/* Reset and Base Styles */
* {
  margin: 0;
  padding: 0;
  box-sizing: border-box;
}

/* Prevent horizontal overflow globally */
* {
  max-width: 100%;
}

pre, code {
  overflow-wrap: break-word;
  word-wrap: break-word;
}

:root {
  /* Light theme colors */
  --primary-color: #2563eb;
  --primary-hover: #1d4ed8;
  --secondary-color: #64748b;
  --accent-color: #f59e0b;
  --success-color: #10b981;
  --error-color: #ef4444;
  --warning-color: #f59e0b;

  --bg-primary: #ffffff;
  --bg-secondary: #f8fafc;
  --bg-tertiary: #f1f5f9;
  --bg-code: #1e293b;

  --text-primary: #1e293b;
  --text-secondary: #64748b;
  --text-muted: #94a3b8;
  --text-inverse: #ffffff;

  --border-color: #e2e8f0;
  --border-hover: #cbd5e1;

  --shadow-sm: 0 1px 2px 0 rgb(0 0 0 / 0.05);
  --shadow-md: 0 4px 6px -1px rgb(0 0 0 / 0.1), 0 2px 4px -2px rgb(0 0 0 / 0.1);
  --shadow-lg: 0 10px 15px -3px rgb(0 0 0 / 0.1), 0 4px 6px -4px rgb(0 0 0 / 0.1);
  --shadow-xl: 0 20px 25px -5px rgb(0 0 0 / 0.1), 0 8px 10px -6px rgb(0 0 0 / 0.1);

  --radius-sm: 0.375rem;
  --radius-md: 0.5rem;
  --radius-lg: 0.75rem;
  --radius-xl: 1rem;

  --font-sans: "Inter", -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, sans-serif;
  --font-mono: "Fira Code", "Monaco", "Cascadia Code", "Roboto Mono", monospace;

  --transition: all 0.2s ease-in-out;
  --transition-slow: all 0.3s ease-in-out;
}

/* Dark theme colors */
[data-theme="dark"] {
  --bg-primary: #0f172a;
  --bg-secondary: #1e293b;
  --bg-tertiary: #334155;
  --bg-code: #0f172a;

  --text-primary: #f8fafc;
  --text-secondary: #cbd5e1;
  --text-muted: #64748b;
  --text-inverse: #1e293b;

  --border-color: #334155;
  --border-hover: #475569;
}

html {
  overflow-x: hidden;
}

body {
  font-family: var(--font-sans);
  line-height: 1.6;
  color: var(--text-primary);
  background-color: var(--bg-primary);
  transition: var(--transition);
  overflow-x: hidden;
  max-width: 100vw;
}

/* Typography */
h1,
h2,
h3,
h4,
h5,
h6 {
  font-weight: 600;
  line-height: 1.3;
  margin-bottom: 0.5rem;
}

h1 {
  font-size: 2.5rem;
}
h2 {
  font-size: 2rem;
}
h3 {
  font-size: 1.5rem;
}
h4 {
  font-size: 1.25rem;
}
h5 {
  font-size: 1.125rem;
}
h6 {
  font-size: 1rem;
}

p {
  margin-bottom: 1rem;
  color: var(--text-secondary);
}

a {
  color: var(--primary-color);
  text-decoration: none;
  transition: var(--transition);
}

a:hover {
  color: var(--primary-hover);
}

/* Container */
.container {
  max-width: 1200px;
  margin: 0 auto;
  padding: 0 1rem;
  overflow-x: hidden;
  width: 100%;
  box-sizing: border-box;
}

/* Navigation */
.navbar {
  background-color: var(--bg-primary);
  border-bottom: 1px solid var(--border-color);
  position: sticky;
  top: 0;
  z-index: 1000;
  backdrop-filter: blur(10px);
  transition: var(--transition);
}

.nav-container {
  display: flex;
  justify-content: space-between;
  align-items: center;
  padding: 1rem;
  max-width: 1200px;
  margin: 0 auto;
}

.nav-logo {
  display: flex;
  align-items: center;
  gap: 0.5rem;
  font-size: 1.25rem;
  font-weight: 700;
  color: var(--primary-color);
}

.nav-logo i {
  font-size: 1.5rem;
}

.nav-menu {
  display: flex;
  list-style: none;
  align-items: center;
  gap: 2rem;
}

.nav-item {
  position: relative;
}

.nav-link {
  color: var(--text-primary);
  font-weight: 500;
  padding: 0.5rem 1rem;
  border-radius: var(--radius-md);
  transition: var(--transition);
  display: flex;
  align-items: center;
  gap: 0.5rem;
}

.nav-link:hover,
.nav-link.active {
  background-color: var(--bg-secondary);
  color: var(--primary-color);
}

/* Dropdown */
.dropdown-content {
  position: absolute;
  top: 100%;
  left: 0;
  background-color: var(--bg-primary);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-md);
  box-shadow: var(--shadow-lg);
  min-width: 200px;
  opacity: 0;
  visibility: hidden;
  transform: translateY(-10px);
  transition: var(--transition);
  z-index: 1000;
}

.dropdown:hover .dropdown-content {
  opacity: 1;
  visibility: visible;
  transform: translateY(0);
}

.dropdown-content a {
  display: block;
  padding: 0.75rem 1rem;
  color: var(--text-primary);
  border-bottom: 1px solid var(--border-color);
  transition: var(--transition);
}

.dropdown-content a:last-child {
  border-bottom: none;
}

.dropdown-content a:hover,
.dropdown-content a.active {
  background-color: var(--bg-secondary);
  color: var(--primary-color);
}

/* Theme Toggle */
.theme-toggle {
  background: none;
  border: 1px solid var(--border-color);
  color: var(--text-primary);
  padding: 0.5rem;
  border-radius: var(--radius-md);
  cursor: pointer;
  transition: var(--transition);
  display: flex;
  align-items: center;
  justify-content: center;
  width: 40px;
  height: 40px;
}

.theme-toggle:hover {
  background-color: var(--bg-secondary);
  border-color: var(--border-hover);
}

/* Hamburger Menu */
.hamburger {
  display: none;
  flex-direction: column;
  cursor: pointer;
  gap: 4px;
}

.hamburger .bar {
  width: 25px;
  height: 3px;
  background-color: var(--text-primary);
  transition: var(--transition);
}

/* Buttons */
.btn {
  display: inline-flex;
  align-items: center;
  gap: 0.5rem;
  padding: 0.875rem 1.75rem;
  border: none;
  border-radius: var(--radius-lg);
  font-weight: 600;
  text-decoration: none;
  cursor: pointer;
  transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
  font-size: 0.875rem;
  line-height: 1;
  position: relative;
  overflow: hidden;
}

.btn::before {
  content: '';
  position: absolute;
  top: 0;
  left: -100%;
  width: 100%;
  height: 100%;
  background: linear-gradient(90deg, transparent, rgba(255,255,255,0.2), transparent);
  transition: left 0.5s;
}

.btn:hover::before {
  left: 100%;
}

.btn-primary {
  background: linear-gradient(135deg, var(--primary-color), var(--primary-hover));
  color: white;
  box-shadow: 0 4px 15px rgba(99, 102, 241, 0.3);
}

.btn-primary:hover {
  background: linear-gradient(135deg, var(--primary-hover), var(--primary-color));
  color: white;
  transform: translateY(-2px);
  box-shadow: 0 8px 25px rgba(99, 102, 241, 0.4);
}

.btn-secondary {
  background-color: var(--bg-secondary);
  color: var(--text-primary);
  border: 2px solid var(--border-color);
  box-shadow: 0 4px 15px rgba(0, 0, 0, 0.1);
}

.btn-secondary:hover {
  background-color: var(--bg-tertiary);
  border-color: var(--primary-color);
  color: var(--primary-color);
  transform: translateY(-2px);
  box-shadow: 0 8px 25px rgba(0, 0, 0, 0.15);
}

.btn-success {
  background: linear-gradient(135deg, var(--success-color), #059669);
  color: white;
  box-shadow: 0 4px 15px rgba(16, 185, 129, 0.3);
}

.btn-success:hover {
  background: linear-gradient(135deg, #059669, var(--success-color));
  color: white;
  transform: translateY(-2px);
  box-shadow: 0 8px 25px rgba(16, 185, 129, 0.4);
}

/* Hero Section */
.hero {
  padding: 3rem 0;
  background: linear-gradient(135deg, var(--bg-primary) 0%, var(--bg-secondary) 100%);
  position: relative;
  overflow: hidden;
}

.hero::before {
  content: '';
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  bottom: 0;
  background: radial-gradient(circle at 20% 80%, rgba(120, 119, 198, 0.1) 0%, transparent 50%),
              radial-gradient(circle at 80% 20%, rgba(255, 119, 198, 0.1) 0%, transparent 50%);
  pointer-events: none;
}

.hero-content {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 2rem;
  align-items: center;
  max-width: 1000px;
  margin: 0 auto;
  padding: 0 1rem;
  position: relative;
  z-index: 1;
}

.hero-title {
  font-size: 2.5rem;
  font-weight: 700;
  margin-bottom: 1rem;
  background: linear-gradient(135deg, var(--primary-color), var(--accent-color));
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
  line-height: 1.1;
  letter-spacing: -0.02em;
}

.hero-subtitle {
  font-size: 1rem;
  color: var(--text-secondary);
  margin-bottom: 1.5rem;
  line-height: 1.6;
  font-weight: 400;
}

.hero-buttons {
  display: flex;
  gap: 1rem;
  flex-wrap: wrap;
}

.hero-visual {
  display: flex;
  justify-content: center;
  position: relative;
}

.code-preview {
  background-color: var(--bg-code);
  border-radius: var(--radius-lg);
  overflow: hidden;
  box-shadow: 0 15px 30px -12px rgba(0, 0, 0, 0.25);
  max-width: 100%;
  transform: perspective(1000px) rotateY(-5deg) rotateX(2deg);
  transition: transform 0.3s ease;
  font-size: 0.8rem;
}

.code-preview:hover {
  transform: perspective(1000px) rotateY(-2deg) rotateX(1deg);
}

.code-header {
  background-color: #374151;
  padding: 0.5rem 0.75rem;
  display: flex;
  align-items: center;
  gap: 0.75rem;
}

.code-dots {
  display: flex;
  gap: 0.375rem;
}

.code-dots span {
  width: 10px;
  height: 10px;
  border-radius: 50%;
  background-color: #6b7280;
}

.code-dots span:nth-child(1) {
  background-color: #ef4444;
}
.code-dots span:nth-child(2) {
  background-color: #f59e0b;
}
.code-dots span:nth-child(3) {
  background-color: #10b981;
}

.code-title {
  color: #d1d5db;
  font-size: 0.75rem;
  font-family: var(--font-mono);
}

.code-preview pre {
  padding: 1rem;
  margin: 0;
  background: transparent;
  color: #e5e7eb;
  font-family: var(--font-mono);
  font-size: 0.75rem;
  line-height: 1.5;
  overflow-x: auto;
}

/* Features Section */
.features {
  padding: 4rem 0;
  background-color: var(--bg-secondary);
}

.section-title {
  text-align: center;
  font-size: 1.75rem;
  font-weight: 700;
  margin-bottom: 2rem;
  color: var(--text-primary);
}

.features-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
  gap: 2rem;
  max-width: 1200px;
  margin: 0 auto;
  padding: 0 1rem;
}

.feature-card {
  background-color: var(--bg-primary);
  padding: 2rem;
  border-radius: var(--radius-lg);
  box-shadow: var(--shadow-md);
  text-align: center;
  transition: var(--transition);
  border: 1px solid var(--border-color);
}

.feature-card:hover {
  transform: translateY(-5px);
  box-shadow: var(--shadow-lg);
}

.feature-icon {
  width: 60px;
  height: 60px;
  background: linear-gradient(135deg, var(--primary-color), var(--accent-color));
  border-radius: 50%;
  display: flex;
  align-items: center;
  justify-content: center;
  margin: 0 auto 1rem;
  color: white;
  font-size: 1.5rem;
}

.feature-card h3 {
  font-size: 1.25rem;
  font-weight: 600;
  margin-bottom: 1rem;
  color: var(--text-primary);
}

.feature-card p {
  color: var(--text-secondary);
  line-height: 1.6;
}

/* Learning Path Section */
.learning-path {
  padding: 3rem 0;
  background: linear-gradient(135deg, var(--bg-primary) 0%, var(--bg-secondary) 100%);
  position: relative;
}

.learning-path::before {
  content: '';
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  bottom: 0;
  background: radial-gradient(circle at 30% 20%, rgba(99, 102, 241, 0.05) 0%, transparent 50%);
  pointer-events: none;
}

.path-container {
  max-width: 900px;
  margin: 0 auto;
  padding: 0 1rem;
  position: relative;
  z-index: 1;
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 1.5rem;
}

.path-item {
  display: flex;
  align-items: flex-start;
  gap: 1rem;
  padding: 1.5rem;
  background: rgba(255, 255, 255, 0.05);
  backdrop-filter: blur(10px);
  border-radius: var(--radius-lg);
  border: 1px solid rgba(255, 255, 255, 0.1);
  transition: all 0.4s cubic-bezier(0.4, 0, 0.2, 1);
  position: relative;
  overflow: hidden;
}

.path-item::before {
  content: '';
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  bottom: 0;
  background: linear-gradient(135deg, rgba(99, 102, 241, 0.1), rgba(168, 85, 247, 0.1));
  opacity: 0;
  transition: opacity 0.3s ease;
}

.path-item:hover::before {
  opacity: 1;
}

.path-item:hover {
  transform: translateY(-5px);
  box-shadow: 0 15px 30px rgba(0, 0, 0, 0.15);
  border-color: rgba(99, 102, 241, 0.3);
}

.path-number {
  width: 40px;
  height: 40px;
  background: linear-gradient(135deg, var(--primary-color), var(--accent-color));
  color: white;
  border-radius: 50%;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 1.25rem;
  font-weight: 700;
  flex-shrink: 0;
  box-shadow: 0 8px 20px rgba(99, 102, 241, 0.3);
  position: relative;
  z-index: 2;
}

.path-content h3 {
  font-size: 1.25rem;
  font-weight: 700;
  margin-bottom: 0.5rem;
  color: var(--text-primary);
  position: relative;
  z-index: 2;
}

.path-content p {
  color: var(--text-secondary);
  margin-bottom: 1rem;
  font-size: 0.875rem;
  line-height: 1.5;
  position: relative;
  z-index: 2;
}

.path-link {
  color: var(--primary-color);
  font-weight: 600;
  display: inline-flex;
  align-items: center;
  gap: 0.5rem;
  transition: all 0.3s ease;
  text-decoration: none;
  padding: 0.375rem 0.75rem;
  border-radius: var(--radius-md);
  background: rgba(99, 102, 241, 0.1);
  position: relative;
  z-index: 2;
  font-size: 0.875rem;
}

.path-link:hover {
  color: var(--primary-hover);
  transform: translateX(3px);
  background: rgba(99, 102, 241, 0.2);
}

/* Quick Start Section */
.quick-start {
  padding: 5rem 0;
  background: linear-gradient(135deg, var(--bg-secondary) 0%, var(--bg-primary) 100%);
  position: relative;
}

.quick-start::before {
  content: '';
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  bottom: 0;
  background: radial-gradient(circle at 70% 80%, rgba(168, 85, 247, 0.05) 0%, transparent 50%);
  pointer-events: none;
}

.quick-start-content {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 4rem;
  align-items: center;
  max-width: 1200px;
  margin: 0 auto;
  padding: 0 1rem;
  position: relative;
  z-index: 1;
}

.quick-start-text h3 {
  font-size: 2.25rem;
  font-weight: 700;
  margin-bottom: 1.5rem;
  color: var(--text-primary);
  line-height: 1.2;
}

.quick-start-text p {
  font-size: 1.125rem;
  color: var(--text-secondary);
  margin-bottom: 2.5rem;
  line-height: 1.6;
}

.quick-start-list {
  list-style: none;
  margin-bottom: 2.5rem;
}

.quick-start-list li {
  display: flex;
  align-items: center;
  gap: 1rem;
  margin-bottom: 1rem;
  color: var(--text-secondary);
  padding: 0.75rem;
  background: rgba(99, 102, 241, 0.05);
  border-radius: var(--radius-md);
  transition: all 0.3s ease;
}

.quick-start-list li:hover {
  background: rgba(99, 102, 241, 0.1);
  transform: translateX(5px);
}

.quick-start-list i {
  color: var(--success-color);
  font-size: 1.25rem;
  width: 20px;
  text-align: center;
}

.demo-card {
  background: rgba(255, 255, 255, 0.05);
  backdrop-filter: blur(10px);
  border-radius: var(--radius-xl);
  padding: 2.5rem;
  box-shadow: 0 25px 50px rgba(0, 0, 0, 0.15);
  border: 1px solid rgba(255, 255, 255, 0.1);
  position: relative;
  overflow: hidden;
}

.demo-card::before {
  content: '';
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  bottom: 0;
  background: linear-gradient(135deg, rgba(99, 102, 241, 0.1), rgba(168, 85, 247, 0.1));
  opacity: 0.5;
}

.demo-card h4 {
  font-size: 1.5rem;
  font-weight: 700;
  margin-bottom: 1.5rem;
  color: var(--text-primary);
  position: relative;
  z-index: 2;
}

.demo-code {
  background-color: var(--bg-code);
  border-radius: var(--radius-lg);
  padding: 1.5rem;
  margin-bottom: 1.5rem;
  box-shadow: inset 0 2px 4px rgba(0, 0, 0, 0.3);
  position: relative;
  z-index: 2;
}

.demo-code pre {
  margin: 0;
  color: #e5e7eb;
  font-family: var(--font-mono);
  font-size: 0.875rem;
  line-height: 1.5;
}

.demo-output {
  display: flex;
  align-items: center;
  gap: 0.5rem;
  padding: 0.75rem;
  background-color: var(--bg-tertiary);
  border-radius: var(--radius-md);
  border-left: 4px solid var(--success-color);
}

.output-label {
  font-weight: 600;
  color: var(--text-primary);
  font-size: 0.875rem;
}

.output-text {
  color: var(--success-color);
  font-family: var(--font-mono);
  font-size: 0.875rem;
}

/* Page Container */
.page-container {
  display: grid;
  grid-template-columns: 280px 1fr;
  min-height: calc(100vh - 80px);
  gap: 0;
}

/* Sidebar */
.sidebar {
  background-color: var(--bg-secondary);
  border-right: 1px solid var(--border-color);
  padding: 2rem 0;
  position: sticky;
  top: 80px;
  height: calc(100vh - 80px);
  overflow-y: auto;
}

.sidebar-content {
  padding: 0 1.5rem;
}

.sidebar h3 {
  font-size: 1.125rem;
  font-weight: 600;
  margin-bottom: 1rem;
  color: var(--text-primary);
}

.toc {
  list-style: none;
}

.toc li {
  margin-bottom: 0.5rem;
}

.toc a {
  display: block;
  padding: 0.5rem 0.75rem;
  color: var(--text-secondary);
  border-radius: var(--radius-md);
  transition: var(--transition);
  font-size: 0.875rem;
}

.toc a:hover {
  background-color: var(--bg-primary);
  color: var(--primary-color);
}

/* Main Content */
.main-content {
  padding: 2rem;
  max-width: none;
  overflow-x: hidden;
  width: 100%;
  box-sizing: border-box;
}

.content-header {
  margin-bottom: 3rem;
  text-align: center;
}

.content-header h1 {
  font-size: 2.5rem;
  font-weight: 700;
  margin-bottom: 0.5rem;
  color: var(--text-primary);
}

.content-header p {
  font-size: 1.125rem;
  color: var(--text-secondary);
  margin-bottom: 2rem;
}

/* Progress Bar */
.progress-bar {
  width: 100%;
  height: 8px;
  background-color: var(--bg-tertiary);
  border-radius: var(--radius-sm);
  overflow: hidden;
}

.progress-fill {
  height: 100%;
  background: linear-gradient(90deg, var(--primary-color), var(--accent-color));
  border-radius: var(--radius-sm);
  transition: width 0.3s ease;
  width: 0%;
}

/* Content Sections */
.content-sections {
  margin-bottom: 3rem;
}

.content-section {
  margin-bottom: 2rem;
  overflow-x: hidden;
  width: 100%;
  box-sizing: border-box;
}

/* Accordion */
.accordion-item {
  background-color: var(--bg-primary);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-lg);
  margin-bottom: 1rem;
  overflow: hidden;
  transition: var(--transition);
}

.accordion-item:hover {
  box-shadow: var(--shadow-md);
}

.accordion-header {
  padding: 1.5rem;
  cursor: pointer;
  display: flex;
  justify-content: space-between;
  align-items: center;
  background-color: var(--bg-secondary);
  transition: var(--transition);
}

.accordion-header:hover {
  background-color: var(--bg-tertiary);
}

.accordion-header h2 {
  display: flex;
  align-items: center;
  gap: 0.75rem;
  font-size: 1.25rem;
  font-weight: 600;
  color: var(--text-primary);
  margin: 0;
}

.accordion-header i:last-child {
  transition: transform 0.3s ease;
  color: var(--text-secondary);
}

.accordion-item.active .accordion-header i:last-child {
  transform: rotate(180deg);
}

.accordion-content {
  max-height: 0;
  overflow: hidden;
  transition: max-height 0.3s ease;
  width: 100%;
  box-sizing: border-box;
}

.topic-content {
  padding: 2rem;
  display: flex;
  flex-direction: column;
  overflow-x: hidden;
  width: 100%;
  box-sizing: border-box;
}

/* Code Blocks */
.code-block {
  background-color: var(--bg-code);
  border-radius: var(--radius-lg);
  margin: 1.5rem 0;
  overflow: hidden;
  box-shadow: var(--shadow-md);
  position: relative;
  z-index: 1;
  order: 1;
  width: 100%;
  max-width: 100%;
  box-sizing: border-box;
}

.code-block .code-header {
  background-color: #374151;
  padding: 0.75rem 1rem;
  display: flex;
  justify-content: space-between;
  align-items: center;
}

.copy-btn {
  background: none;
  border: 1px solid #6b7280;
  color: #d1d5db;
  padding: 0.25rem 0.75rem;
  border-radius: var(--radius-sm);
  font-size: 0.75rem;
  cursor: pointer;
  transition: var(--transition);
  display: flex;
  align-items: center;
  gap: 0.25rem;
}

.copy-btn:hover {
  background-color: #4b5563;
  border-color: #9ca3af;
}

.code-block pre {
  padding: 1.5rem;
  margin: 0;
  background: transparent;
  color: #e5e7eb;
  font-family: var(--font-mono);
  font-size: 0.875rem;
  line-height: 1.6;
  overflow-x: auto;
  white-space: pre-wrap;
  word-wrap: break-word;
  max-width: 100%;
}

/* Info Boxes */
.info-box {
  background-color: var(--bg-secondary);
  border: 1px solid var(--border-color);
  border-left: 4px solid var(--primary-color);
  border-radius: var(--radius-md);
  padding: 1rem;
  margin: 1.5rem 0;
  display: flex;
  align-items: flex-start;
  gap: 0.75rem;
  position: relative;
  z-index: 1;
  order: 2; /* Ensure info-boxes appear after code blocks */
}

.info-box i {
  color: var(--primary-color);
  font-size: 1.125rem;
  margin-top: 0.125rem;
  flex-shrink: 0;
}

.info-box p {
  margin: 0;
  color: var(--text-secondary);
}

/* Output Box */
.output-box {
  background-color: var(--bg-tertiary);
  border: 1px solid var(--border-color);
  border-left: 4px solid var(--success-color);
  border-radius: var(--radius-md);
  padding: 1rem;
  margin: 1.5rem 0;
}

.output-box h4 {
  color: var(--text-primary);
  margin-bottom: 0.5rem;
  font-size: 1rem;
}

.output-box pre {
  margin: 0;
  color: var(--success-color);
  font-family: var(--font-mono);
  font-size: 0.875rem;
  background: transparent;
}

/* Syntax Box */
.syntax-box {
  background-color: var(--bg-tertiary);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-md);
  padding: 1rem;
  margin: 1rem 0;
  text-align: center;
}

.syntax-box code {
  font-family: var(--font-mono);
  font-size: 1rem;
  color: var(--primary-color);
  font-weight: 500;
}

/* Data Types Grid */
.data-types-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
  gap: 1.5rem;
  margin: 1.5rem 0;
}

.data-type-card {
  background-color: var(--bg-secondary);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-md);
  padding: 1.5rem;
}

.data-type-card h4 {
  color: var(--text-primary);
  margin-bottom: 1rem;
  font-size: 1.125rem;
}

.data-type-card ul {
  list-style: none;
}

.data-type-card li {
  padding: 0.25rem 0;
  color: var(--text-secondary);
  font-family: var(--font-mono);
  font-size: 0.875rem;
}

/* Operators Grid */
.operators-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
  gap: 1.5rem;
  margin: 1.5rem 0;
}

.operator-category {
  background-color: var(--bg-secondary);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-md);
  padding: 1.5rem;
}

.operator-category h4 {
  color: var(--text-primary);
  margin-bottom: 1rem;
  font-size: 1rem;
}

.operator-category ul {
  list-style: none;
}

.operator-category li {
  padding: 0.25rem 0;
  color: var(--text-secondary);
  font-size: 0.875rem;
}

.operator-category code {
  font-family: var(--font-mono);
  background-color: var(--bg-tertiary);
  padding: 0.125rem 0.25rem;
  border-radius: var(--radius-sm);
  color: var(--primary-color);
  font-weight: 500;
}

/* OOP Pillars */
.oop-pillars {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
  gap: 1.5rem;
  margin: 2rem 0;
}

.pillar-card {
  background-color: var(--bg-secondary);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-lg);
  padding: 2rem;
  text-align: center;
  transition: var(--transition);
}

.pillar-card:hover {
  transform: translateY(-5px);
  box-shadow: var(--shadow-md);
}

.pillar-icon {
  width: 60px;
  height: 60px;
  background: linear-gradient(135deg, var(--primary-color), var(--accent-color));
  border-radius: 50%;
  display: flex;
  align-items: center;
  justify-content: center;
  margin: 0 auto 1rem;
  color: white;
  font-size: 1.5rem;
}

.pillar-card h4 {
  font-size: 1.25rem;
  font-weight: 600;
  margin-bottom: 0.75rem;
  color: var(--text-primary);
}

.pillar-card p {
  color: var(--text-secondary);
  font-size: 0.875rem;
  line-height: 1.5;
}

/* Access Modifiers Grid */
.access-modifiers-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
  gap: 1.5rem;
  margin: 1.5rem 0;
}

.access-modifier-card {
  background-color: var(--bg-secondary);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-md);
  padding: 1.5rem;
  text-align: center;
}

.access-modifier-card h4 {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 0.5rem;
  color: var(--text-primary);
  margin-bottom: 0.75rem;
  font-size: 1.125rem;
}

.access-modifier-card p {
  color: var(--text-secondary);
  font-size: 0.875rem;
  margin: 0;
}

/* STL Components */
.stl-components {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
  gap: 1.5rem;
  margin: 2rem 0;
}

.component-card {
  background-color: var(--bg-secondary);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-lg);
  padding: 2rem;
  text-align: center;
  transition: var(--transition);
}

.component-card:hover {
  transform: translateY(-5px);
  box-shadow: var(--shadow-md);
}

.component-icon {
  width: 60px;
  height: 60px;
  background: linear-gradient(135deg, var(--primary-color), var(--accent-color));
  border-radius: 50%;
  display: flex;
  align-items: center;
  justify-content: center;
  margin: 0 auto 1rem;
  color: white;
  font-size: 1.5rem;
}

.component-card h4 {
  font-size: 1.25rem;
  font-weight: 600;
  margin-bottom: 0.75rem;
  color: var(--text-primary);
}

.component-card p {
  color: var(--text-secondary);
  font-size: 0.875rem;
  line-height: 1.5;
}

/* Project Features */
.project-features {
  background-color: var(--bg-secondary);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-md);
  padding: 1.5rem;
  margin: 1.5rem 0;
  width: 100%;
  max-width: 100%;
  box-sizing: border-box;
  overflow-x: hidden;
}

.project-features h3 {
  color: var(--text-primary);
  margin-bottom: 1rem;
  font-size: 1.125rem;
}

.project-features ul {
  list-style: none;
  margin: 0;
}

.project-features li {
  display: flex;
  align-items: center;
  gap: 0.5rem;
  padding: 0.25rem 0;
  color: var(--text-secondary);
}

.project-features li::before {
  content: "✓";
  color: var(--success-color);
  font-weight: bold;
  font-size: 1rem;
}

/* Navigation Buttons */
.navigation-buttons {
  display: flex;
  justify-content: space-between;
  align-items: center;
  margin-top: 3rem;
  padding-top: 2rem;
  border-top: 1px solid var(--border-color);
}

/* Quiz Styles */
.quiz-container {
  max-width: 900px;
  margin: 0 auto;
  padding: 2rem 1rem;
  min-height: calc(100vh - 160px);
}

/* Enhanced Quiz Header */
.quiz-header {
  text-align: center;
  margin-bottom: 4rem;
  position: relative;
}

.quiz-hero {
  position: relative;
  padding: 3rem 0;
  border-radius: var(--radius-xl);
  background: linear-gradient(135deg, 
    rgba(37, 99, 235, 0.1) 0%, 
    rgba(79, 70, 229, 0.1) 50%, 
    rgba(147, 51, 234, 0.1) 100%);
  backdrop-filter: blur(20px);
  border: 1px solid rgba(255, 255, 255, 0.1);
  overflow: hidden;
}

.hero-bg-animation {
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  bottom: 0;
  z-index: -1;
}

.floating-shapes {
  position: absolute;
  width: 100%;
  height: 100%;
}

.shape {
  position: absolute;
  background: linear-gradient(45deg, var(--primary-color), var(--accent-color));
  border-radius: 50%;
  opacity: 0.1;
  animation: float 6s ease-in-out infinite;
  will-change: transform;
  transform: translateZ(0);
}

.shape-1 {
  width: 60px;
  height: 60px;
  top: 20%;
  left: 10%;
  animation-delay: 0s;
}

.shape-2 {
  width: 40px;
  height: 40px;
  top: 60%;
  right: 15%;
  animation-delay: 2s;
}

.shape-3 {
  width: 80px;
  height: 80px;
  bottom: 20%;
  left: 60%;
  animation-delay: 4s;
}

@keyframes float {
  0%, 100% { transform: translateY(0px) rotate(0deg); }
  50% { transform: translateY(-20px) rotate(180deg); }
}

.quiz-header h1 {
  font-size: 3rem;
  font-weight: 700;
  margin-bottom: 1rem;
  color: var(--text-primary);
  background: linear-gradient(135deg, var(--primary-color), var(--accent-color));
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}

.quiz-header p {
  font-size: 1.25rem;
  color: var(--text-secondary);
  margin-bottom: 2rem;
  max-width: 600px;
  margin-left: auto;
  margin-right: auto;
}

.quiz-stats-overview {
  display: flex;
  justify-content: center;
  gap: 2rem;
  margin-top: 2rem;
}

.stat-card {
  background: rgba(255, 255, 255, 0.1);
  backdrop-filter: blur(10px);
  border: 1px solid rgba(255, 255, 255, 0.2);
  border-radius: var(--radius-lg);
  padding: 1.5rem;
  display: flex;
  align-items: center;
  gap: 1rem;
  transition: var(--transition);
  cursor: pointer;
}

.stat-card:hover {
  transform: translateY(-5px);
  box-shadow: 0 10px 25px rgba(37, 99, 235, 0.2);
}

.stat-icon {
  font-size: 2rem;
  width: 50px;
  height: 50px;
  display: flex;
  align-items: center;
  justify-content: center;
  background: linear-gradient(135deg, var(--primary-color), var(--accent-color));
  border-radius: 50%;
  color: white;
}

.stat-info {
  text-align: left;
}

.stat-number {
  font-size: 1.5rem;
  font-weight: 700;
  color: var(--text-primary);
  margin-bottom: 0.25rem;
}

.stat-label {
  font-size: 0.875rem;
  color: var(--text-secondary);
  text-transform: uppercase;
  font-weight: 500;
  letter-spacing: 0.05em;
}

/* Enhanced Selection Header */
.selection-header {
  text-align: center;
  margin-bottom: 3rem;
}

.selection-header h2 {
  font-size: 2rem;
  font-weight: 600;
  color: var(--text-primary);
  margin-bottom: 0.5rem;
}

.selection-header p {
  font-size: 1.125rem;
  color: var(--text-secondary);
}

/* Enhanced Quiz Topics */
.quiz-topics {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(320px, 1fr));
  gap: 2rem;
  margin-bottom: 3rem;
}

.quiz-topic-card {
  background: linear-gradient(135deg, var(--bg-primary), var(--bg-secondary));
  border: 1px solid var(--border-color);
  border-radius: var(--radius-xl);
  padding: 2rem;
  text-align: center;
  cursor: pointer;
  transition: all 0.3s ease;
  box-shadow: var(--shadow-sm);
  position: relative;
  overflow: hidden;
}

.quiz-topic-card::before {
  content: '';
  position: absolute;
  top: 0;
  left: -100%;
  width: 100%;
  height: 100%;
  background: linear-gradient(90deg, transparent, rgba(255,255,255,0.1), transparent);
  transition: left 0.5s;
}

.quiz-topic-card:hover::before {
  left: 100%;
}

.quiz-topic-card:hover {
  transform: translateY(-8px);
  box-shadow: 0 15px 35px rgba(37, 99, 235, 0.15);
  border-color: var(--primary-color);
}

.card-header {
  display: flex;
  justify-content: space-between;
  align-items: flex-start;
  margin-bottom: 1.5rem;
}

.quiz-topic-card .topic-icon {
  width: 70px;
  height: 70px;
  background: linear-gradient(135deg, var(--primary-color), var(--accent-color));
  border-radius: 50%;
  display: flex;
  align-items: center;
  justify-content: center;
  color: white;
  font-size: 1.75rem;
  box-shadow: 0 4px 15px rgba(37, 99, 235, 0.3);
}

.difficulty-badge {
  padding: 0.5rem 1rem;
  border-radius: var(--radius-full);
  font-size: 0.75rem;
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 0.05em;
}

.difficulty-badge.beginner {
  background: linear-gradient(135deg, #10b981, #34d399);
  color: white;
}

.difficulty-badge.intermediate {
  background: linear-gradient(135deg, #f59e0b, #fbbf24);
  color: white;
}

.difficulty-badge.advanced {
  background: linear-gradient(135deg, #ef4444, #f87171);
  color: white;
}

.quiz-topic-card h3 {
  font-size: 1.5rem;
  font-weight: 600;
  margin-bottom: 0.75rem;
  color: var(--text-primary);
}

.quiz-topic-card p {
  color: var(--text-secondary);
  margin-bottom: 1.5rem;
  line-height: 1.6;
}

.topic-stats {
  display: flex;
  justify-content: center;
  gap: 2rem;
  font-size: 0.875rem;
  color: var(--text-muted);
  margin-bottom: 1.5rem;
}

.topic-stats span {
  display: flex;
  align-items: center;
  gap: 0.5rem;
}

.progress-preview {
  margin-top: 1rem;
  text-align: left;
}

.progress-bar-mini {
  height: 4px;
  background-color: var(--bg-tertiary);
  border-radius: var(--radius-full);
  overflow: hidden;
  margin-bottom: 0.5rem;
}

.progress-fill-mini {
  height: 100%;
  background: linear-gradient(90deg, var(--primary-color), var(--accent-color));
  border-radius: var(--radius-full);
  transition: width 0.3s ease;
}

.progress-text {
  font-size: 0.75rem;
  color: var(--text-muted);
  font-weight: 500;
}

.card-glow {
  position: absolute;
  top: -50%;
  left: -50%;
  width: 200%;
  height: 200%;
  background: radial-gradient(circle, rgba(37, 99, 235, 0.1) 0%, transparent 70%);
  opacity: 0;
  transition: opacity 0.3s ease;
  pointer-events: none;
}

.quiz-topic-card:hover .card-glow {
  opacity: 1;
}

/* Enhanced Quiz Content */
.quiz-header-nav {
  display: flex;
  justify-content: space-between;
  align-items: center;
  margin-bottom: 2rem;
  padding-bottom: 1rem;
  border-bottom: 1px solid var(--border-color);
}

.back-to-topics-btn {
  display: flex;
  align-items: center;
  gap: 0.5rem;
  background: var(--bg-secondary);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-md);
  padding: 0.75rem 1rem;
  color: var(--text-primary);
  text-decoration: none;
  transition: var(--transition);
  cursor: pointer;
  font-size: 0.875rem;
}

.back-to-topics-btn:hover {
  background: var(--bg-tertiary);
  border-color: var(--primary-color);
  transform: translateX(-3px);
}

.quiz-tools {
  display: flex;
  gap: 0.5rem;
}

.tool-btn {
  background: var(--bg-secondary);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-md);
  padding: 0.75rem;
  color: var(--text-primary);
  cursor: pointer;
  transition: var(--transition);
  font-size: 0.875rem;
}

.tool-btn:hover {
  background: var(--primary-color);
  color: white;
  border-color: var(--primary-color);
}

.quiz-progress {
  background: linear-gradient(135deg, var(--bg-secondary), var(--bg-primary));
  border: 1px solid var(--border-color);
  border-radius: var(--radius-xl);
  padding: 2rem;
  margin-bottom: 2rem;
  box-shadow: var(--shadow-sm);
}

.progress-info {
  display: flex;
  justify-content: space-between;
  align-items: center;
  margin-bottom: 1.5rem;
  font-weight: 500;
  color: var(--text-primary);
}

.timer-container {
  display: flex;
  align-items: center;
  gap: 0.5rem;
  background: rgba(37, 99, 235, 0.1);
  padding: 0.5rem 1rem;
  border-radius: var(--radius-full);
  color: var(--primary-color);
  font-weight: 600;
}

.progress-bar {
  height: 8px;
  background-color: var(--bg-tertiary);
  border-radius: var(--radius-full);
  overflow: hidden;
  margin-bottom: 1rem;
}

.progress-fill {
  height: 100%;
  background: linear-gradient(90deg, var(--primary-color), var(--accent-color));
  border-radius: var(--radius-full);
  transition: width 0.3s ease;
}

.progress-steps {
  display: flex;
  justify-content: space-between;
  margin-top: 1rem;
}

.progress-step {
  width: 12px;
  height: 12px;
  border-radius: 50%;
  background-color: var(--bg-tertiary);
  transition: var(--transition);
}

.progress-step.completed {
  background: linear-gradient(135deg, var(--primary-color), var(--accent-color));
}

.progress-step.current {
  background: linear-gradient(135deg, var(--primary-color), var(--accent-color));
  box-shadow: 0 0 0 4px rgba(37, 99, 235, 0.3);
}

.question-container {
  background: linear-gradient(135deg, var(--bg-primary), var(--bg-secondary));
  border: 1px solid var(--border-color);
  border-radius: var(--radius-xl);
  padding: 2rem;
  margin-bottom: 2rem;
  box-shadow: var(--shadow-sm);
  position: relative;
}

.question-header {
  display: flex;
  align-items: flex-start;
  gap: 1rem;
  margin-bottom: 2rem;
}

.question-number-badge {
  background: linear-gradient(135deg, var(--primary-color), var(--accent-color));
  color: white;
  border-radius: 50%;
  width: 40px;
  height: 40px;
  display: flex;
  align-items: center;
  justify-content: center;
  font-weight: 600;
  font-size: 0.875rem;
  flex-shrink: 0;
}

.question-container h2 {
  flex: 1;
  font-size: 1.5rem;
  font-weight: 600;
  margin: 0;
  color: var(--text-primary);
  line-height: 1.5;
}

.code-snippet {
  background-color: var(--bg-code);
  border-radius: var(--radius-lg);
  margin: 1.5rem 0;
  overflow: hidden;
  border: 1px solid rgba(255, 255, 255, 0.1);
}

.code-header {
  display: flex;
  justify-content: space-between;
  align-items: center;
  padding: 1rem 1.5rem;
  background: rgba(0, 0, 0, 0.3);
  border-bottom: 1px solid rgba(255, 255, 255, 0.1);
}

.code-title {
  color: #e5e7eb;
  font-size: 0.875rem;
  font-weight: 500;
}

.copy-code-btn {
  background: transparent;
  border: 1px solid rgba(255, 255, 255, 0.2);
  border-radius: var(--radius-md);
  padding: 0.25rem 0.75rem;
  color: #e5e7eb;
  cursor: pointer;
  transition: var(--transition);
  font-size: 0.75rem;
}

.copy-code-btn:hover {
  background: rgba(255, 255, 255, 0.1);
  border-color: var(--primary-color);
}

.code-snippet pre {
  margin: 0;
  padding: 1.5rem;
  color: #e5e7eb;
  font-family: var(--font-mono);
  font-size: 0.875rem;
  line-height: 1.6;
  overflow-x: auto;
}

.options-container {
  display: grid;
  gap: 1rem;
}

.option {
  background: linear-gradient(135deg, var(--bg-secondary), var(--bg-primary));
  border: 2px solid var(--border-color);
  border-radius: var(--radius-lg);
  padding: 1rem 1.5rem;
  cursor: pointer;
  transition: all 0.3s ease;
  display: flex;
  align-items: center;
  gap: 1rem;
  position: relative;
  overflow: hidden;
}

.option::before {
  content: '';
  position: absolute;
  top: 0;
  left: -100%;
  width: 100%;
  height: 100%;
  background: linear-gradient(90deg, transparent, rgba(37, 99, 235, 0.1), transparent);
  transition: left 0.5s;
}

.option:hover::before {
  left: 100%;
}

.option:hover {
  border-color: var(--primary-color);
  transform: translateX(5px);
  box-shadow: 0 4px 15px rgba(37, 99, 235, 0.2);
}

.option.selected {
  border-color: var(--primary-color);
  background: linear-gradient(135deg, rgba(37, 99, 235, 0.1), rgba(79, 70, 229, 0.05));
}

.option.correct {
  border-color: var(--success-color);
  background: linear-gradient(135deg, rgba(16, 185, 129, 0.1), rgba(34, 197, 94, 0.05));
}

.option.incorrect {
  border-color: var(--error-color);
  background: linear-gradient(135deg, rgba(239, 68, 68, 0.1), rgba(248, 113, 113, 0.05));
}

.option-letter {
  width: 35px;
  height: 35px;
  background: var(--bg-tertiary);
  border-radius: 50%;
  display: flex;
  align-items: center;
  justify-content: center;
  font-weight: 600;
  color: var(--text-primary);
  flex-shrink: 0;
  transition: var(--transition);
}

.option.selected .option-letter {
  background: linear-gradient(135deg, var(--primary-color), var(--accent-color));
  color: white;
}

.option.correct .option-letter {
  background: linear-gradient(135deg, var(--success-color), #34d399);
  color: white;
}

.option.incorrect .option-letter {
  background: linear-gradient(135deg, var(--error-color), #f87171);
  color: white;
}

.option-text {
  color: var(--text-primary);
  font-weight: 500;
  line-height: 1.5;
}

.quiz-controls {
  display: flex;
  justify-content: space-between;
  align-items: center;
  gap: 1rem;
  padding: 1.5rem;
  background: var(--bg-secondary);
  border-radius: var(--radius-lg);
  border: 1px solid var(--border-color);
}

.control-center {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 0.5rem;
}

.question-counter {
  background: var(--bg-primary);
  padding: 0.5rem 1rem;
  border-radius: var(--radius-full);
  border: 1px solid var(--border-color);
  font-weight: 600;
  color: var(--text-primary);
  font-size: 0.875rem;
}

/* Enhanced Quiz Results */
.quiz-results {
  background: linear-gradient(135deg, var(--bg-primary), var(--bg-secondary));
  border-radius: var(--radius-xl);
  padding: 2rem;
  margin-bottom: 2rem;
  border: 1px solid var(--border-color);
}

.results-header {
  text-align: center;
  margin-bottom: 3rem;
}

.score-circle-container {
  position: relative;
  width: 150px;
  height: 150px;
  margin: 0 auto 2rem;
}

.score-circle {
  width: 100%;
  height: 100%;
  transform: rotate(-90deg);
}

.score-bg {
  fill: none;
  stroke: var(--bg-tertiary);
  stroke-width: 8;
}

.score-progress {
  fill: none;
  stroke: url(#scoreGradient);
  stroke-width: 8;
  stroke-linecap: round;
  stroke-dasharray: 339.3;
  stroke-dashoffset: 339.3;
  transition: stroke-dashoffset 2s ease-in-out;
}

.score-text {
  position: absolute;
  top: 50%;
  left: 50%;
  transform: translate(-50%, -50%);
  text-align: center;
}

.score-text span {
  display: block;
  font-size: 2.5rem;
  font-weight: 700;
  background: linear-gradient(135deg, var(--primary-color), var(--accent-color));
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}

.score-text small {
  font-size: 0.875rem;
  color: var(--text-secondary);
  text-transform: uppercase;
  font-weight: 500;
  letter-spacing: 0.05em;
}

.results-header h2 {
  font-size: 2rem;
  font-weight: 600;
  color: var(--text-primary);
  margin-bottom: 0.5rem;
}

.results-header p {
  font-size: 1.125rem;
  color: var(--text-secondary);
  margin-bottom: 1.5rem;
}

.performance-badge {
  display: inline-flex;
  align-items: center;
  gap: 0.5rem;
  background: linear-gradient(135deg, var(--success-color), #34d399);
  color: white;
  padding: 0.75rem 1.5rem;
  border-radius: var(--radius-full);
  font-weight: 600;
  font-size: 0.875rem;
}

.results-stats {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(150px, 1fr));
  gap: 1.5rem;
  margin-bottom: 3rem;
}

.result-stat {
  background: rgba(255, 255, 255, 0.05);
  backdrop-filter: blur(10px);
  border: 1px solid rgba(255, 255, 255, 0.1);
  border-radius: var(--radius-lg);
  padding: 1.5rem;
  text-align: center;
  transition: var(--transition);
}

.result-stat:hover {
  transform: translateY(-5px);
  box-shadow: 0 10px 25px rgba(37, 99, 235, 0.15);
}

.results-breakdown {
  margin-bottom: 3rem;
}

.results-breakdown h3 {
  font-size: 1.5rem;
  font-weight: 600;
  color: var(--text-primary);
  margin-bottom: 1.5rem;
  text-align: center;
}

.breakdown-container {
  background: var(--bg-secondary);
  border-radius: var(--radius-lg);
  padding: 1.5rem;
  border: 1px solid var(--border-color);
}

.results-actions {
  display: flex;
  justify-content: center;
  gap: 1rem;
  flex-wrap: wrap;
}

.progress-info {
  display: flex;
  justify-content: space-between;
  align-items: center;
  margin-bottom: 1rem;
  font-weight: 500;
  color: var(--text-primary);
}

.question-container {
  background-color: var(--bg-primary);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-lg);
  padding: 2rem;
  margin-bottom: 2rem;
}

.question-container h2 {
  font-size: 1.5rem;
  font-weight: 600;
  margin-bottom: 1.5rem;
  color: var(--text-primary);
  line-height: 1.4;
}

.code-snippet {
  background-color: var(--bg-code);
  border-radius: var(--radius-md);
  padding: 1.5rem;
  margin: 1.5rem 0;
  overflow-x: auto;
}

.code-snippet pre {
  margin: 0;
  color: #e5e7eb;
  font-family: var(--font-mono);
  font-size: 0.875rem;
  line-height: 1.6;
}

.options-container {
  display: grid;
  gap: 1rem;
}

.option {
  background-color: var(--bg-secondary);
  border: 2px solid var(--border-color);
  border-radius: var(--radius-md);
  padding: 1rem 1.5rem;
  cursor: pointer;
  transition: var(--transition);
  display: flex;
  align-items: center;
  gap: 1rem;
}

.option:hover {
  border-color: var(--primary-color);
  background-color: var(--bg-tertiary);
}

.option.selected {
  border-color: var(--primary-color);
  background-color: rgba(37, 99, 235, 0.1);
}

.option.correct {
  border-color: var(--success-color);
  background-color: rgba(16, 185, 129, 0.1);
}

.option.incorrect {
  border-color: var(--error-color);
  background-color: rgba(239, 68, 68, 0.1);
}

.option-letter {
  width: 30px;
  height: 30px;
  background-color: var(--bg-tertiary);
  border-radius: 50%;
  display: flex;
  align-items: center;
  justify-content: center;
  font-weight: 600;
  color: var(--text-primary);
  flex-shrink: 0;
}

.option.selected .option-letter {
  background-color: var(--primary-color);
  color: white;
}

.option.correct .option-letter {
  background-color: var(--success-color);
  color: white;
}

.option.incorrect .option-letter {
  background-color: var(--error-color);
  color: white;
}

.option-text {
  color: var(--text-primary);
  font-weight: 500;
}

.quiz-controls {
  display: flex;
  justify-content: space-between;
  align-items: center;
  gap: 1rem;
}

/* Quiz Results */
.results-header {
  text-align: center;
  margin-bottom: 3rem;
}

.score-circle {
  width: 150px;
  height: 150px;
  border-radius: 50%;
  background: conic-gradient(var(--primary-color) 0deg, var(--primary-color) 0deg, var(--bg-tertiary) 0deg);
  display: flex;
  align-items: center;
  justify-content: center;
  margin: 0 auto 2rem;
  position: relative;
}

.score-circle::before {
  content: "";
  position: absolute;
  width: 120px;
  height: 120px;
  background-color: var(--bg-primary);
  border-radius: 50%;
}

.score-text {
  position: relative;
  z-index: 1;
  text-align: center;
}

.score-text span {
  display: block;
  font-size: 2rem;
  font-weight: 700;
  color: var(--primary-color);
}

.score-text small {
  color: var(--text-secondary);
  font-size: 0.875rem;
}

.results-header h2 {
  font-size: 2rem;
  font-weight: 700;
  margin-bottom: 0.5rem;
  color: var(--text-primary);
}

.results-stats {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 2rem;
  margin-bottom: 3rem;
}

.stat-item {
  text-align: center;
  background-color: var(--bg-secondary);
  border-radius: var(--radius-lg);
  padding: 2rem;
  border: 1px solid var(--border-color);
}

.stat-number {
  font-size: 2.5rem;
  font-weight: 700;
  color: var(--primary-color);
  margin-bottom: 0.5rem;
}

.stat-label {
  color: var(--text-secondary);
  font-weight: 500;
}

.results-breakdown {
  background-color: var(--bg-secondary);
  border-radius: var(--radius-lg);
  padding: 2rem;
  margin-bottom: 3rem;
  border: 1px solid var(--border-color);
}

.results-actions {
  display: flex;
  justify-content: center;
  gap: 1rem;
  flex-wrap: wrap;
}

/* Footer */
.footer {
  background: var(--bg-secondary);
  border-top: 1px solid rgba(255, 255, 255, 0.1);
  padding: 1.5rem 0;
  margin-top: 2rem;
}

.footer-bottom {
  text-align: center;
  color: var(--text-muted);
  font-size: 0.875rem;
  max-width: 1000px;
  margin: 0 auto;
  padding: 0 1rem;
}

/* Responsive Design */
@media (max-width: 1024px) {
  .page-container {
    grid-template-columns: 250px 1fr;
  }

  .hero-content {
    grid-template-columns: 1fr;
    gap: 2rem;
    text-align: center;
  }

  .hero-title {
    font-size: 3rem;
  }

  .quick-start-content {
    grid-template-columns: 1fr;
    gap: 2rem;
  }
}

@media (max-width: 768px) {
  .page-container {
    grid-template-columns: 1fr;
  }

  .sidebar {
    display: none;
  }

  .nav-menu {
    position: fixed;
    top: 80px;
    left: -100%;
    width: 100%;
    height: calc(100vh - 80px);
    background-color: var(--bg-primary);
    flex-direction: column;
    justify-content: flex-start;
    align-items: center;
    padding: 2rem 0;
    transition: left 0.3s ease;
    border-top: 1px solid var(--border-color);
  }

  .nav-menu.active {
    left: 0;
  }

  .hamburger {
    display: flex;
  }

  .hamburger.active .bar:nth-child(2) {
    opacity: 0;
  }

  .hamburger.active .bar:nth-child(1) {
    transform: translateY(7px) rotate(45deg);
  }

  .hamburger.active .bar:nth-child(3) {
    transform: translateY(-7px) rotate(-45deg);
  }

  .hero-title {
    font-size: 2rem;
  }

  .hero-buttons {
    justify-content: center;
  }

  .features-grid {
    grid-template-columns: 1fr;
  }

  .path-container {
    grid-template-columns: 1fr;
    gap: 1rem;
  }

  .path-item {
    flex-direction: column;
    text-align: center;
    gap: 1rem;
    padding: 1.25rem;
  }

  .main-content {
    padding: 1rem;
  }

  .navigation-buttons {
    flex-direction: column;
    gap: 1rem;
  }

  .quiz-topics {
    grid-template-columns: 1fr;
    gap: 1.5rem;
  }

  .quiz-stats-overview {
    flex-direction: column;
    gap: 1rem;
  }

  .stat-card {
    justify-content: center;
  }

  .quiz-header h1 {
    font-size: 2.5rem;
  }

  .quiz-hero {
    padding: 2rem 1rem;
  }

  .quiz-header-nav {
    flex-direction: column;
    gap: 1rem;
    align-items: stretch;
  }

  .quiz-controls {
    flex-direction: column;
    gap: 1rem;
  }

  .control-center {
    order: -1;
  }

  .question-header {
    flex-direction: column;
    align-items: stretch;
    gap: 1rem;
  }

  .question-number-badge {
    align-self: flex-start;
  }

  .results-stats {
    grid-template-columns: repeat(2, 1fr);
    gap: 1rem;
  }

  .results-actions {
    flex-direction: column;
    align-items: center;
    gap: 1rem;
  }

  .topic-stats {
    flex-direction: column;
    gap: 0.5rem;
  }

  .card-header {
    flex-direction: column;
    gap: 1rem;
    align-items: center;
  }
}

@media (max-width: 480px) {
  .hero-title {
    font-size: 2rem;
  }

  .section-title {
    font-size: 2rem;
  }

  .content-header h1 {
    font-size: 2rem;
  }

  .quiz-header h1 {
    font-size: 2rem;
  }

  .quiz-hero {
    padding: 1.5rem 0.5rem;
  }

  .stat-card {
    padding: 1rem;
  }

  .stat-icon {
    font-size: 1.5rem;
    width: 40px;
    height: 40px;
  }

  .stat-number {
    font-size: 1.25rem;
  }

  .quiz-topic-card {
    padding: 1.5rem;
  }

  .topic-icon {
    width: 60px !important;
    height: 60px !important;
    font-size: 1.5rem !important;
  }

  .question-container {
    padding: 1.5rem;
  }

  .score-circle-container {
    width: 120px;
    height: 120px;
  }

  .score-text span {
    font-size: 2rem;
  }

  .btn {
    padding: 0.75rem 1rem;
    font-size: 0.875rem;
  }

  .quiz-controls {
    flex-direction: column;
    gap: 1rem;
  }

  .quiz-controls .btn {
    width: 100%;
    justify-content: center;
  }
}

/* Animation Classes */
.fade-in {
  animation: fadeIn 0.5s ease-in-out;
}

.slide-in-left {
  animation: slideInLeft 0.5s ease-in-out;
}

.slide-in-right {
  animation: slideInRight 0.5s ease-in-out;
}

.bounce-in {
  animation: bounceIn 0.6s ease-in-out;
}

@keyframes fadeIn {
  from {
    opacity: 0;
    transform: translateY(20px);
  }
  to {
    opacity: 1;
    transform: translateY(0);
  }
}

@keyframes slideInLeft {
  from {
    opacity: 0;
    transform: translateX(-50px);
  }
  to {
    opacity: 1;
    transform: translateX(0);
  }
}

@keyframes slideInRight {
  from {
    opacity: 0;
    transform: translateX(50px);
  }
  to {
    opacity: 1;
    transform: translateX(0);
  }
}

@keyframes bounceIn {
  0% {
    opacity: 0;
    transform: scale(0.3);
  }
  50% {
    opacity: 1;
    transform: scale(1.05);
  }
  70% {
    transform: scale(0.9);
  }
  100% {
    opacity: 1;
    transform: scale(1);
  }
}

/* Utility Classes */
.text-center {
  text-align: center;
}
.text-left {
  text-align: left;
}
.text-right {
  text-align: right;
}

.mt-1 {
  margin-top: 0.25rem;
}
.mt-2 {
  margin-top: 0.5rem;
}
.mt-3 {
  margin-top: 0.75rem;
}
.mt-4 {
  margin-top: 1rem;
}

.mb-1 {
  margin-bottom: 0.25rem;
}
.mb-2 {
  margin-bottom: 0.5rem;
}
.mb-3 {
  margin-bottom: 0.75rem;
}
.mb-4 {
  margin-bottom: 1rem;
}

.p-1 {
  padding: 0.25rem;
}
.p-2 {
  padding: 0.5rem;
}
.p-3 {
  padding: 0.75rem;
}
.p-4 {
  padding: 1rem;
}

.hidden {
  display: none;
}
.block {
  display: block;
}
.flex {
  display: flex;
}
.grid {
  display: grid;
}

.w-full {
  width: 100%;
}
.h-full {
  height: 100%;
}

/* Print Styles */
@media print {
  .navbar,
  .sidebar,
  .navigation-buttons,
  .footer {
    display: none;
  }

  .page-container {
    grid-template-columns: 1fr;
  }

  .main-content {
    padding: 0;
  }

  .accordion-content {
    max-height: none !important;
  }

  .code-block {
    break-inside: avoid;
  }
}

/* Additional UI Elements for Enhanced Basics Page */

/* Rules List */
.rules-list ul {
  list-style: none;
  padding-left: 0;
}

.rules-list li {
  padding: 0.5rem 0;
  color: var(--text-secondary);
  position: relative;
  padding-left: 1.5rem;
}

.rules-list li::before {
  content: "✓";
  position: absolute;
  left: 0;
  color: var(--success-color);
  font-weight: bold;
}

/* Loop Types Grid */
.loop-types-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
  gap: 1.5rem;
  margin: 1.5rem 0;
}

.loop-type-card {
  background: linear-gradient(135deg, var(--bg-secondary) 0%, var(--bg-tertiary) 100%);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-lg);
  padding: 1.5rem;
  text-align: center;
  transition: var(--transition);
}

.loop-type-card:hover {
  transform: translateY(-2px);
  box-shadow: var(--shadow-lg);
}

.loop-type-card h4 {
  color: var(--primary-color);
  margin-bottom: 0.5rem;
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 0.5rem;
}

.loop-type-card i {
  font-size: 1.25rem;
}

/* Control Statements */
.control-statements {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
  gap: 1rem;
  margin: 1.5rem 0;
}

.control-item {
  background-color: var(--bg-secondary);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-md);
  padding: 1rem;
  text-align: center;
}

.control-item h4 {
  color: var(--primary-color);
  margin-bottom: 0.5rem;
  font-family: var(--font-mono);
}

.control-item p {
  color: var(--text-secondary);
  font-size: 0.875rem;
  margin: 0;
}

/* Function Parameters Info */
.parameters-info {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
  gap: 1rem;
  margin: 1.5rem 0;
}

.param-type {
  background-color: var(--bg-secondary);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-md);
  padding: 1rem;
  text-align: center;
}

.param-type h4 {
  color: var(--primary-color);
  margin-bottom: 0.5rem;
}

.param-type p {
  color: var(--text-secondary);
  font-size: 0.875rem;
  margin: 0;
}

/* String Operations */
.string-operations {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
  gap: 1rem;
  margin: 1.5rem 0;
}

.operation-item {
  background-color: var(--bg-secondary);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-md);
  padding: 1rem;
}

.operation-item code {
  font-family: var(--font-mono);
  background-color: var(--bg-tertiary);
  padding: 0.25rem 0.5rem;
  border-radius: var(--radius-sm);
  color: var(--primary-color);
  font-weight: 500;
  display: block;
  margin-bottom: 0.5rem;
}

.operation-item p {
  color: var(--text-secondary);
  font-size: 0.875rem;
  margin: 0;
}

/* Pointer Operators */
.pointer-operators {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
  gap: 1rem;
  margin: 1.5rem 0;
}

.operator-item {
  background-color: var(--bg-secondary);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-md);
  padding: 1rem;
  text-align: center;
}

.operator-item code {
  font-family: var(--font-mono);
  background-color: var(--bg-tertiary);
  padding: 0.25rem 0.5rem;
  border-radius: var(--radius-sm);
  color: var(--primary-color);
  font-weight: 500;
  font-size: 1.25rem;
  display: block;
  margin-bottom: 0.5rem;
}

.operator-item p {
  color: var(--text-secondary);
  font-size: 0.875rem;
  margin: 0;
}

/* Benefits List */
.benefits-list {
  list-style: none;
  padding-left: 0;
}

.benefits-list li {
  padding: 0.75rem 0;
  color: var(--text-secondary);
  position: relative;
  padding-left: 2rem;
  border-bottom: 1px solid var(--border-color);
}

.benefits-list li:last-child {
  border-bottom: none;
}

.benefits-list li::before {
  content: "🎯";
  position: absolute;
  left: 0;
  font-size: 1.25rem;
}

.benefits-list strong {
  color: var(--text-primary);
}

/* Enhanced Info Boxes */
.info-box {
  background: linear-gradient(135deg, var(--bg-secondary) 0%, var(--bg-tertiary) 100%);
  border-left: 4px solid var(--accent-color);
  padding: 1rem 1.5rem;
  margin: 1.5rem 0;
  border-radius: var(--radius-md);
  box-shadow: var(--shadow-sm);
  display: block;
  clear: both;
  position: relative;
  z-index: 1;
}

.info-box i {
  color: var(--accent-color);
  margin-right: 0.5rem;
  font-size: 1.125rem;
}

/* Ensure info-box appears after code-block */
.code-block + .info-box {
  margin-top: 1.5rem;
  order: 10;
  float: none !important;
  position: static !important;
}

.performance-table + .info-box {
  margin-top: 1.5rem;
}

/* Force proper flow for containers section */
.content-section .topic-content {
  display: block;
}

.content-section .topic-content > * {
  display: block;
  position: relative;
}

/* Output Box */
.output-box {
  background-color: var(--bg-code);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-md);
  padding: 1rem;
  margin: 1rem 0;
}

.output-box h4 {
  color: var(--text-inverse);
  margin-bottom: 0.5rem;
  font-size: 0.875rem;
  text-transform: uppercase;
  letter-spacing: 0.5px;
}

.output-box pre {
  margin: 0;
  color: var(--success-color);
  font-family: var(--font-mono);
  font-size: 0.875rem;
}

/* Enhanced Mobile Responsiveness */
@media (max-width: 768px) {
  .loop-types-grid,
  .control-statements,
  .parameters-info,
  .string-operations,
  .pointer-operators {
    grid-template-columns: 1fr;
  }
  
  .data-types-grid {
    grid-template-columns: 1fr;
  }
  
  .operators-grid {
    grid-template-columns: repeat(2, 1fr);
  }
}

@media (max-width: 480px) {
  .operators-grid {
    grid-template-columns: 1fr;
  }
}

/* New UI Elements for Enhanced Content */

/* Why C++ Grid */
.why-cpp-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
  gap: 1.5rem;
  margin: 2rem 0;
}

.reason-card {
  background: linear-gradient(135deg, var(--bg-secondary) 0%, var(--bg-tertiary) 100%);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-lg);
  padding: 2rem;
  text-align: center;
  transition: var(--transition);
}

.reason-card:hover {
  transform: translateY(-5px);
  box-shadow: var(--shadow-lg);
}

.reason-card i {
  font-size: 2.5rem;
  color: var(--primary-color);
  margin-bottom: 1rem;
}

.reason-card h4 {
  color: var(--text-primary);
  margin-bottom: 0.75rem;
  font-size: 1.25rem;
}

.reason-card p {
  color: var(--text-secondary);
  font-size: 0.875rem;
  margin: 0;
  line-height: 1.5;
}

/* Feature List */
.feature-list {
  list-style: none;
  padding-left: 0;
}

.feature-list li {
  padding: 0.75rem 0;
  color: var(--text-secondary);
  position: relative;
  padding-left: 2rem;
  border-bottom: 1px solid var(--border-color);
}

.feature-list li:last-child {
  border-bottom: none;
}

.feature-list li::before {
  content: "⚡";
  position: absolute;
  left: 0;
  font-size: 1.25rem;
}

.feature-list strong {
  color: var(--text-primary);
}

/* Timeline */
.timeline {
  position: relative;
  padding: 2rem 0;
}

.timeline::before {
  content: '';
  position: absolute;
  left: 50%;
  top: 0;
  bottom: 0;
  width: 2px;
  background: linear-gradient(to bottom, var(--primary-color), var(--accent-color));
  transform: translateX(-50%);
}

.timeline-item {
  display: flex;
  align-items: center;
  margin-bottom: 2rem;
  position: relative;
}

.timeline-item:nth-child(even) {
  flex-direction: row-reverse;
}

.timeline-date {
  background: linear-gradient(135deg, var(--primary-color), var(--accent-color));
  color: white;
  padding: 0.75rem 1.5rem;
  border-radius: var(--radius-lg);
  font-weight: 600;
  min-width: 100px;
  text-align: center;
  position: relative;
  z-index: 2;
}

.timeline-content {
  background-color: var(--bg-secondary);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-lg);
  padding: 1.5rem;
  margin: 0 2rem;
  flex: 1;
  box-shadow: var(--shadow-sm);
}

.timeline-content h4 {
  color: var(--text-primary);
  margin-bottom: 0.5rem;
  font-size: 1.125rem;
}

.timeline-content p {
  color: var(--text-secondary);
  margin: 0;
  font-size: 0.875rem;
}

/* Applications Grid */
.applications-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
  gap: 2rem;
  margin: 2rem 0;
}

.app-category {
  background-color: var(--bg-secondary);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-lg);
  padding: 2rem;
  text-align: center;
  transition: var(--transition);
}

.app-category:hover {
  transform: translateY(-5px);
  box-shadow: var(--shadow-md);
}

.app-category i {
  font-size: 2.5rem;
  color: var(--primary-color);
  margin-bottom: 1rem;
}

.app-category h4 {
  color: var(--text-primary);
  margin-bottom: 1rem;
  font-size: 1.25rem;
}

.app-category ul {
  list-style: none;
  padding: 0;
}

.app-category li {
  padding: 0.25rem 0;
  color: var(--text-secondary);
  font-size: 0.875rem;
}

/* Setup Requirements */
.setup-requirements {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
  gap: 2rem;
  margin: 2rem 0;
}

.requirement-card {
  background-color: var(--bg-secondary);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-lg);
  padding: 2rem;
  transition: var(--transition);
}

.requirement-card:hover {
  box-shadow: var(--shadow-md);
}

.requirement-card h4 {
  display: flex;
  align-items: center;
  gap: 0.75rem;
  color: var(--text-primary);
  margin-bottom: 1rem;
  font-size: 1.25rem;
}

.requirement-card i {
  font-size: 1.5rem;
  color: var(--primary-color);
}

.requirement-card ul {
  list-style: none;
  padding: 0;
}

.requirement-card li {
  padding: 0.5rem 0;
  color: var(--text-secondary);
  position: relative;
  padding-left: 1.5rem;
}

.requirement-card li::before {
  content: "✓";
  position: absolute;
  left: 0;
  color: var(--success-color);
  font-weight: bold;
}

/* Step Cards */
.setup-steps {
  display: grid;
  gap: 1.5rem;
  margin: 2rem 0;
}

.step-card {
  background-color: var(--bg-secondary);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-lg);
  padding: 2rem;
  position: relative;
  transition: var(--transition);
}

.step-card:hover {
  transform: translateX(10px);
  box-shadow: var(--shadow-md);
}

.step-number {
  position: absolute;
  top: -15px;
  left: 2rem;
  background: linear-gradient(135deg, var(--primary-color), var(--accent-color));
  color: white;
  width: 40px;
  height: 40px;
  border-radius: 50%;
  display: flex;
  align-items: center;
  justify-content: center;
  font-weight: 700;
  font-size: 1.125rem;
}

.step-card h4 {
  color: var(--text-primary);
  margin-bottom: 1rem;
  margin-top: 0.5rem;
  font-size: 1.25rem;
}

.step-card p {
  color: var(--text-secondary);
  margin-bottom: 1rem;
  line-height: 1.6;
}

/* Enhanced Mobile Responsiveness for New Elements */
@media (max-width: 768px) {
  .why-cpp-grid,
  .applications-grid,
  .setup-requirements {
    grid-template-columns: 1fr;
  }
  
  .timeline::before {
    left: 20px;
  }
  
  .timeline-item {
    flex-direction: column !important;
    align-items: flex-start;
    padding-left: 3rem;
  }
  
  .timeline-item:nth-child(even) {
    flex-direction: column !important;
  }
  
  .timeline-date {
    margin-bottom: 1rem;
  }
  
  .timeline-content {
    margin: 0;
  }
}

@media (max-width: 480px) {
  .reason-card,
  .app-category,
  .requirement-card {
    padding: 1.5rem;
  }
  
  .step-card {
    padding: 1.5rem;
  }
  
  .step-number {
    width: 35px;
    height: 35px;
    font-size: 1rem;
  }
}

/* Compilation Pipeline Styles */
.compilation-pipeline {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 1rem;
  margin: 2rem 0;
}

.pipeline-step {
  background: var(--bg-secondary);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-lg);
  padding: 2rem;
  width: 100%;
  max-width: 600px;
  text-align: center;
  transition: var(--transition);
}

.pipeline-step:hover {
  border-color: var(--primary-color);
  transform: translateY(-2px);
  box-shadow: var(--shadow-lg);
}

.pipeline-step.final {
  background: linear-gradient(135deg, var(--primary-color), var(--accent-color));
  color: var(--text-inverse);
  border-color: var(--primary-color);
}

.step-icon {
  background: var(--primary-color);
  color: var(--text-inverse);
  width: 60px;
  height: 60px;
  border-radius: 50%;
  display: flex;
  align-items: center;
  justify-content: center;
  margin: 0 auto 1rem;
  font-size: 1.5rem;
}

.pipeline-step.final .step-icon {
  background: rgba(255, 255, 255, 0.2);
}

.pipeline-arrow {
  font-size: 2rem;
  color: var(--primary-color);
  margin: 0.5rem 0;
}

.pipeline-step h4 {
  color: var(--text-primary);
  margin-bottom: 0.5rem;
  font-size: 1.25rem;
}

.pipeline-step.final h4 {
  color: var(--text-inverse);
}

.pipeline-step p {
  color: var(--text-secondary);
  margin-bottom: 1rem;
}

.pipeline-step.final p {
  color: rgba(255, 255, 255, 0.9);
}

.pipeline-step ul {
  text-align: left;
  margin-left: 1rem;
}

.pipeline-step li {
  color: var(--text-secondary);
  margin-bottom: 0.25rem;
}

.pipeline-step.final li {
  color: rgba(255, 255, 255, 0.9);
}

/* Compilation Commands Styles */
.compilation-commands {
  margin: 2rem 0;
}

.compilation-commands h4 {
  color: var(--text-primary);
  margin: 2rem 0 1rem;
  font-size: 1.1rem;
}

.compiler-flags {
  background: var(--bg-secondary);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-md);
  padding: 1.5rem;
  margin: 1rem 0;
}

.compiler-flags ul {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
  gap: 0.5rem;
  list-style: none;
}

.compiler-flags li {
  display: flex;
  align-items: center;
  padding: 0.5rem 0;
  color: var(--text-secondary);
}

.compiler-flags code {
  background: var(--accent-color);
  color: var(--text-inverse);
  padding: 0.25rem 0.5rem;
  border-radius: var(--radius-sm);
  font-family: var(--font-mono);
  font-size: 0.875rem;
  margin-right: 0.5rem;
  min-width: 80px;
  text-align: center;
}

/* Build Systems Styles */
.build-systems {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
  gap: 2rem;
  margin: 2rem 0;
}

.build-system-card {
  background: var(--bg-secondary);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-lg);
  padding: 2rem;
  transition: var(--transition);
}

.build-system-card:hover {
  border-color: var(--primary-color);
  transform: translateY(-2px);
  box-shadow: var(--shadow-md);
}

.build-system-card h4 {
  color: var(--text-primary);
  margin-bottom: 1rem;
  display: flex;
  align-items: center;
  gap: 0.5rem;
}

.build-system-card i {
  color: var(--primary-color);
}

.build-system-card p {
  color: var(--text-secondary);
  margin-bottom: 1rem;
}

.online-compilers {
  background: var(--bg-secondary);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-md);
  padding: 1.5rem;
  margin: 1rem 0;
}

.online-compilers ul {
  list-style: none;
}

.online-compilers li {
  padding: 0.5rem 0;
  border-bottom: 1px solid var(--border-color);
  color: var(--text-secondary);
}

.online-compilers li:last-child {
  border-bottom: none;
}

.online-compilers strong {
  color: var(--primary-color);
}

/* Responsive Design for Compilation Pipeline */
@media (max-width: 768px) {
  .pipeline-step {
    padding: 1.5rem;
  }
  
  .step-icon {
    width: 50px;
    height: 50px;
    font-size: 1.25rem;
  }
  
  .pipeline-arrow {
    font-size: 1.5rem;
  }
  
  .compiler-flags ul {
    grid-template-columns: 1fr;
  }
  
  .build-systems {
    grid-template-columns: 1fr;
  }
}

/* Structures Section Styles */
.concept-cards {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
  gap: 1.5rem;
  margin: 2rem 0;
}

.concept-card {
  background: var(--bg-secondary);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-lg);
  padding: 1.5rem;
  text-align: center;
  transition: var(--transition);
}

.concept-card:hover {
  border-color: var(--primary-color);
  transform: translateY(-2px);
  box-shadow: var(--shadow-md);
}

.concept-card h4 {
  color: var(--text-primary);
  margin-bottom: 1rem;
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 0.5rem;
}

.concept-card i {
  color: var(--primary-color);
}

.concept-card p {
  color: var(--text-secondary);
  margin-bottom: 0.5rem;
}

.concept-card code {
  background: var(--accent-color);
  color: var(--text-inverse);
  padding: 0.25rem 0.5rem;
  border-radius: var(--radius-sm);
  font-family: var(--font-mono);
  font-size: 0.875rem;
}

/* Debugging Section Styles */
.error-types {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
  gap: 2rem;
  margin: 2rem 0;
}

.error-card {
  background: var(--bg-secondary);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-lg);
  padding: 2rem;
  transition: var(--transition);
}

.error-card:hover {
  border-color: var(--error-color);
  box-shadow: var(--shadow-md);
}

.error-card h4 {
  color: var(--text-primary);
  margin-bottom: 1rem;
  display: flex;
  align-items: center;
  gap: 0.5rem;
}

.error-card i {
  color: var(--error-color);
}

.error-card p {
  color: var(--text-secondary);
  margin-bottom: 1rem;
}

.error-card ul {
  list-style-type: disc;
  margin-left: 1.5rem;
}

.error-card li {
  color: var(--text-secondary);
  margin-bottom: 0.5rem;
}

.debug-techniques {
  margin: 2rem 0;
}

.technique-item {
  background: var(--bg-secondary);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-md);
  padding: 2rem;
  margin-bottom: 2rem;
}

.technique-item h4 {
  color: var(--text-primary);
  margin-bottom: 1rem;
  display: flex;
  align-items: center;
  gap: 0.5rem;
}

.technique-item i {
  color: var(--primary-color);
}

.technique-item p {
  color: var(--text-secondary);
  margin-bottom: 1rem;
}

.debug-tools {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
  gap: 2rem;
  margin: 2rem 0;
}

.tool-card {
  background: var(--bg-secondary);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-lg);
  padding: 1.5rem;
  transition: var(--transition);
}

.tool-card:hover {
  border-color: var(--primary-color);
  transform: translateY(-2px);
  box-shadow: var(--shadow-md);
}

.tool-card h4 {
  color: var(--text-primary);
  margin-bottom: 1rem;
  display: flex;
  align-items: center;
  gap: 0.5rem;
}

.tool-card i {
  color: var(--primary-color);
}

.tool-card p {
  color: var(--text-secondary);
  margin-bottom: 1rem;
}

.tool-card code {
  background: var(--bg-code);
  color: var(--text-inverse);
  padding: 0.5rem;
  border-radius: var(--radius-sm);
  font-family: var(--font-mono);
  display: block;
  margin-top: 0.5rem;
}

.debugging-tips {
  background: var(--bg-secondary);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-lg);
  padding: 2rem;
  margin: 2rem 0;
}

.debugging-tips h3 {
  color: var(--text-primary);
  margin-bottom: 1rem;
}

.debugging-tips ul {
  list-style: none;
}

.debugging-tips li {
  color: var(--text-secondary);
  margin-bottom: 1rem;
  padding-left: 1.5rem;
  position: relative;
}

.debugging-tips li::before {
  content: "💡";
  position: absolute;
  left: 0;
  top: 0;
}

/* Best Practices Section Styles */
.best-practice-section {
  margin: 2rem 0;
}

.best-practice-section h4 {
  color: var(--text-primary);
  margin-bottom: 1rem;
  display: flex;
  align-items: center;
  gap: 0.5rem;
}

.best-practice-section i {
  color: var(--primary-color);
}

.code-comparison {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
  gap: 2rem;
  margin: 1rem 0;
}

.good-code,
.bad-code {
  border-radius: var(--radius-lg);
  overflow: hidden;
}

.good-code h5 {
  background: var(--success-color);
  color: var(--text-inverse);
  padding: 0.75rem 1rem;
  margin: 0;
  font-size: 1rem;
}

.bad-code h5 {
  background: var(--error-color);
  color: var(--text-inverse);
  padding: 0.75rem 1rem;
  margin: 0;
  font-size: 1rem;
}

.principles-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
  gap: 2rem;
  margin: 2rem 0;
}

.principle-card {
  background: var(--bg-secondary);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-lg);
  padding: 2rem;
  text-align: center;
  transition: var(--transition);
}

.principle-card:hover {
  border-color: var(--primary-color);
  transform: translateY(-2px);
  box-shadow: var(--shadow-md);
}

.principle-card h4 {
  color: var(--text-primary);
  margin-bottom: 0.5rem;
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 0.5rem;
}

.principle-card i {
  color: var(--primary-color);
}

.principle-card p {
  color: var(--text-secondary);
  margin-bottom: 0.5rem;
}

.principle-card p:first-of-type {
  font-weight: 600;
  color: var(--text-primary);
}

.organization-tips {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
  gap: 2rem;
  margin: 2rem 0;
}

.tip-item {
  background: var(--bg-secondary);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-lg);
  padding: 1.5rem;
}

.tip-item h4 {
  color: var(--text-primary);
  margin-bottom: 1rem;
  display: flex;
  align-items: center;
  gap: 0.5rem;
}

.tip-item i {
  color: var(--primary-color);
}

.tip-item ul {
  list-style-type: disc;
  margin-left: 1.5rem;
}

.tip-item li {
  color: var(--text-secondary);
  margin-bottom: 0.5rem;
}

.safety-tips {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(350px, 1fr));
  gap: 2rem;
  margin: 2rem 0;
}

.safety-card {
  background: var(--bg-secondary);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-lg);
  padding: 2rem;
}

.safety-card h4 {
  color: var(--text-primary);
  margin-bottom: 1rem;
  display: flex;
  align-items: center;
  gap: 0.5rem;
}

.safety-card i {
  color: var(--warning-color);
}

.safety-card ul {
  list-style-type: disc;
  margin-left: 1.5rem;
}

.safety-card li {
  color: var(--text-secondary);
  margin-bottom: 0.5rem;
}

.code-example {
  margin: 3rem 0;
}

.code-example h3 {
  color: var(--text-primary);
  margin-bottom: 1.5rem;
  text-align: center;
}

.success-box {
  background: linear-gradient(135deg, var(--success-color), #059669);
  color: var(--text-inverse);
  border-radius: var(--radius-lg);
  padding: 2rem;
  margin: 3rem 0;
  text-align: center;
}

.success-box i {
  font-size: 2rem;
  margin-bottom: 1rem;
}

.success-box p {
  font-size: 1.1rem;
  margin: 0;
}

/* Responsive Design for New Sections */
@media (max-width: 768px) {
  .concept-cards,
  .error-types,
  .debug-tools,
  .principles-grid,
  .organization-tips,
  .safety-tips {
    grid-template-columns: 1fr;
  }
  
  .code-comparison {
    grid-template-columns: 1fr;
  }
  
  .technique-item,
  .concept-card,
  .error-card,
  .tool-card,
  .principle-card,
  .tip-item,
  .safety-card {
    padding: 1.5rem;
  }
}

/* OOP-Specific Styles */

/* Enhanced OOP Pillars */
.oop-pillars {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
  gap: 2rem;
  margin: 2rem 0;
}

.pillar-card {
  background: var(--bg-secondary);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-lg);
  padding: 2rem;
  text-align: center;
  transition: var(--transition);
  position: relative;
  overflow: hidden;
}

.pillar-card::before {
  content: '';
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  height: 4px;
  background: linear-gradient(90deg, var(--primary-color), var(--accent-color));
}

.pillar-card:hover {
  transform: translateY(-5px);
  box-shadow: var(--shadow-lg);
  border-color: var(--primary-color);
}

.pillar-icon {
  background: linear-gradient(135deg, var(--primary-color), var(--accent-color));
  color: var(--text-inverse);
  width: 80px;
  height: 80px;
  border-radius: 50%;
  display: flex;
  align-items: center;
  justify-content: center;
  margin: 0 auto 1.5rem;
  font-size: 2rem;
}

.pillar-card h4 {
  color: var(--text-primary);
  margin-bottom: 1rem;
  font-size: 1.25rem;
}

.pillar-card p {
  color: var(--text-secondary);
  line-height: 1.6;
  margin-bottom: 1rem;
}

.pillar-example {
  background: var(--bg-tertiary);
  padding: 1rem;
  border-radius: var(--radius-md);
  margin-top: 1rem;
  font-style: italic;
  color: var(--text-secondary);
}

.pillar-example strong {
  color: var(--primary-color);
}

/* Why OOP Grid */
.why-oop-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
  gap: 1.5rem;
  margin: 2rem 0;
}

/* Comparison Table */
.comparison-table {
  background: var(--bg-secondary);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-lg);
  overflow: hidden;
  margin: 2rem 0;
}

.comparison-header {
  display: grid;
  grid-template-columns: 1fr 1fr;
  background: var(--primary-color);
}

.comparison-title {
  padding: 1rem;
  color: var(--text-inverse);
  font-weight: 600;
  text-align: center;
}

.comparison-row {
  display: grid;
  grid-template-columns: 1fr 1fr;
  border-bottom: 1px solid var(--border-color);
}

.comparison-row:last-child {
  border-bottom: none;
}

.comparison-item {
  padding: 1rem;
  display: flex;
  align-items: center;
  gap: 0.5rem;
}

.comparison-item:first-child {
  border-right: 1px solid var(--border-color);
}

.text-success {
  color: var(--success-color);
}

.text-error {
  color: var(--error-color);
}

/* Real World Examples */
.real-world-examples {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
  gap: 2rem;
  margin: 2rem 0;
}

.example-card {
  background: var(--bg-secondary);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-lg);
  padding: 2rem;
  transition: var(--transition);
}

.example-card:hover {
  border-color: var(--primary-color);
  transform: translateY(-2px);
  box-shadow: var(--shadow-md);
}

.example-card h4 {
  color: var(--text-primary);
  margin-bottom: 1rem;
  display: flex;
  align-items: center;
  gap: 0.5rem;
}

.example-card i {
  color: var(--primary-color);
}

.example-card ul {
  list-style: none;
  margin-left: 0;
}

.example-card li {
  color: var(--text-secondary);
  margin-bottom: 0.5rem;
  padding-left: 1rem;
  position: relative;
}

.example-card li::before {
  content: "▸";
  color: var(--primary-color);
  position: absolute;
  left: 0;
}

/* Member Function Types */
.member-function-types {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
  gap: 2rem;
  margin: 2rem 0;
}

.function-type-card {
  background: var(--bg-secondary);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-lg);
  padding: 2rem;
  transition: var(--transition);
}

.function-type-card:hover {
  border-color: var(--primary-color);
  transform: translateY(-2px);
  box-shadow: var(--shadow-md);
}

.function-type-card h4 {
  color: var(--text-primary);
  margin-bottom: 1rem;
  display: flex;
  align-items: center;
  gap: 0.5rem;
}

.function-type-card i {
  color: var(--primary-color);
}

/* Static Points */
.static-points {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
  gap: 2rem;
  margin: 2rem 0;
}

.point-card {
  background: var(--bg-secondary);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-lg);
  padding: 1.5rem;
  text-align: center;
  transition: var(--transition);
}

.point-card:hover {
  border-color: var(--primary-color);
  transform: translateY(-2px);
  box-shadow: var(--shadow-md);
}

.point-card h4 {
  color: var(--text-primary);
  margin-bottom: 1rem;
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 0.5rem;
}

.point-card i {
  color: var(--primary-color);
}

/* Access Modifiers Grid */
.access-modifiers-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
  gap: 2rem;
  margin: 2rem 0;
}

.access-modifier-card {
  background: var(--bg-secondary);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-lg);
  padding: 2rem;
  transition: var(--transition);
}

.access-modifier-card:hover {
  border-color: var(--primary-color);
  transform: translateY(-2px);
  box-shadow: var(--shadow-md);
}

.access-modifier-card h4 {
  color: var(--text-primary);
  margin-bottom: 1rem;
  display: flex;
  align-items: center;
  gap: 0.5rem;
}

.access-modifier-card i {
  color: var(--primary-color);
}

.access-modifier-card ul {
  list-style-type: disc;
  margin-left: 1.5rem;
}

.access-modifier-card li {
  color: var(--text-secondary);
  margin-bottom: 0.5rem;
}

/* Inheritance Types */
.inheritance-types {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
  gap: 1.5rem;
  margin: 2rem 0;
}

.inheritance-type {
  background: var(--bg-secondary);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-md);
  padding: 1.5rem;
  text-align: center;
  transition: var(--transition);
}

.inheritance-type:hover {
  border-color: var(--primary-color);
  transform: translateY(-2px);
  box-shadow: var(--shadow-md);
}

.inheritance-type h4 {
  color: var(--text-primary);
  margin-bottom: 0.5rem;
}

.inheritance-type p {
  color: var(--text-secondary);
  font-size: 0.9rem;
}

/* Operator Types */
.operator-types {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
  gap: 2rem;
  margin: 2rem 0;
}

/* Polymorphism Types */
.polymorphism-types {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
  gap: 1.5rem;
  margin: 2rem 0;
}

.polymorphism-type {
  background: var(--bg-secondary);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-md);
  padding: 1.5rem;
  text-align: center;
  transition: var(--transition);
}

.polymorphism-type:hover {
  border-color: var(--primary-color);
  transform: translateY(-2px);
  box-shadow: var(--shadow-md);
}

.polymorphism-type h4 {
  color: var(--text-primary);
  margin-bottom: 1rem;
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 0.5rem;
}

.polymorphism-type ul {
  list-style: none;
  padding: 0;
  margin: 0;
}

.polymorphism-type li {
  color: var(--text-secondary);
  font-size: 0.9rem;
  margin-bottom: 0.5rem;
  padding-left: 1.5rem;
  position: relative;
}

.polymorphism-type li::before {
  content: "▶";
  position: absolute;
  left: 0;
  color: var(--primary-color);
  font-size: 0.8rem;
}

/* Abstraction Types */
.abstraction-types {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
  gap: 1.5rem;
  margin: 2rem 0;
}

.abstraction-type {
  background: var(--bg-secondary);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-md);
  padding: 1.5rem;
  text-align: center;
  transition: var(--transition);
}

.abstraction-type:hover {
  border-color: var(--primary-color);
  transform: translateY(-2px);
  box-shadow: var(--shadow-md);
}

.abstraction-type h4 {
  color: var(--text-primary);
  margin-bottom: 0.5rem;
}

.abstraction-type p {
  color: var(--text-secondary);
  font-size: 0.9rem;
}

.operator-category {
  background: var(--bg-secondary);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-lg);
  padding: 2rem;
}

.operator-category h4 {
  color: var(--text-primary);
  margin-bottom: 1rem;
}

.operator-category ul {
  list-style-type: disc;
  margin-left: 1.5rem;
}

.operator-category li {
  color: var(--text-secondary);
  margin-bottom: 0.5rem;
}

/* Friend Usage */
.friend-usage {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
  gap: 2rem;
  margin: 2rem 0;
}

.usage-item {
  background: var(--bg-secondary);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-lg);
  padding: 2rem;
  text-align: center;
  transition: var(--transition);
}

.usage-item:hover {
  border-color: var(--primary-color);
  transform: translateY(-2px);
  box-shadow: var(--shadow-md);
}

.usage-item i {
  color: var(--primary-color);
  font-size: 2rem;
  margin-bottom: 1rem;
}

.usage-item h4 {
  color: var(--text-primary);
  margin-bottom: 1rem;
}

.usage-item p {
  color: var(--text-secondary);
}

/* Relationship Comparison */
.relationship-comparison {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(350px, 1fr));
  gap: 2rem;
  margin: 2rem 0;
}

.relationship-card {
  background: var(--bg-secondary);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-lg);
  padding: 2rem;
  transition: var(--transition);
}

.relationship-card:hover {
  border-color: var(--primary-color);
  transform: translateY(-2px);
  box-shadow: var(--shadow-md);
}

.relationship-card h4 {
  color: var(--text-primary);
  margin-bottom: 1rem;
  display: flex;
  align-items: center;
  gap: 0.5rem;
}

.relationship-card i {
  color: var(--primary-color);
}

.relationship-card p {
  color: var(--text-secondary);
  margin-bottom: 0.5rem;
}

.relationship-card p strong {
  color: var(--text-primary);
}

/* SOLID Principles */
.solid-principles {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
  gap: 2rem;
  margin: 2rem 0;
}

.principle-card {
  background: var(--bg-secondary);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-lg);
  padding: 2rem;
  transition: var(--transition);
  position: relative;
}

.principle-card:hover {
  border-color: var(--primary-color);
  transform: translateY(-2px);
  box-shadow: var(--shadow-md);
}

.principle-letter {
  position: absolute;
  top: -10px;
  left: 20px;
  background: var(--primary-color);
  color: var(--text-inverse);
  width: 40px;
  height: 40px;
  border-radius: 50%;
  display: flex;
  align-items: center;
  justify-content: center;
  font-weight: bold;
  font-size: 1.2rem;
}

.principle-card h4 {
  color: var(--text-primary);
  margin: 1rem 0;
  padding-left: 30px;
}

.principle-card p {
  color: var(--text-secondary);
  margin-bottom: 1rem;
}

/* Design Patterns */
.design-patterns {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
  gap: 1.5rem;
  margin: 2rem 0;
}

.pattern-card {
  background: var(--bg-secondary);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-lg);
  padding: 1.5rem;
  text-align: center;
  transition: var(--transition);
}

.pattern-card:hover {
  border-color: var(--accent-color);
  transform: translateY(-2px);
  box-shadow: var(--shadow-md);
}

.pattern-card h4 {
  color: var(--text-primary);
  margin-bottom: 1rem;
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 0.5rem;
}

.pattern-card i {
  color: var(--accent-color);
}

.pattern-card p {
  color: var(--text-secondary);
  font-size: 0.9rem;
}

/* Best Practices Grid */
.best-practices-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
  gap: 2rem;
  margin: 2rem 0;
}

.practice-item {
  background: var(--bg-secondary);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-lg);
  padding: 2rem;
}

.practice-item h4 {
  color: var(--text-primary);
  margin-bottom: 1rem;
  display: flex;
  align-items: center;
  gap: 0.5rem;
}

.practice-item i {
  color: var(--primary-color);
}

.practice-item ul {
  list-style-type: disc;
  margin-left: 1.5rem;
}

.practice-item li {
  color: var(--text-secondary);
  margin-bottom: 0.5rem;
}

/* Responsive Design for OOP Components */
@media (max-width: 768px) {
  .oop-pillars,
  .why-oop-grid,
  .real-world-examples,
  .member-function-types,
  .static-points,
  .access-modifiers-grid,
  .inheritance-types,
  .polymorphism-types,
  .abstraction-types,
  .operator-types,
  .friend-usage,
  .relationship-comparison,
  .solid-principles,
  .design-patterns,
  .best-practices-grid {
    grid-template-columns: 1fr;
  }
  
  .comparison-row {
    grid-template-columns: 1fr;
  }
  
  .comparison-item:first-child {
    border-right: none;
    border-bottom: 1px solid var(--border-color);
  }
  
  .pillar-card,
  .example-card,
  .function-type-card,
  .point-card,
  .access-modifier-card,
  .polymorphism-type,
  .abstraction-type,
  .inheritance-type,
  .relationship-card,
  .principle-card {
    padding: 1.5rem;
  }
  
  .pillar-icon {
    width: 60px;
    height: 60px;
    font-size: 1.5rem;
  }
}

/* Advanced C++ Specific Styles */

/* Advanced Features Grid */
.advanced-features-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
  gap: 1.5rem;
  margin: 2rem 0;
}

.feature-card {
  background: var(--bg-secondary);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-md);
  padding: 1.5rem;
  text-align: center;
  transition: var(--transition);
  position: relative;
  overflow: hidden;
}

.feature-card::before {
  content: '';
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  height: 3px;
  background: linear-gradient(90deg, var(--primary-color), var(--secondary-color));
}

.feature-card:hover {
  transform: translateY(-5px);
  box-shadow: var(--shadow-lg);
  border-color: var(--primary-color);
}

.feature-card i {
  font-size: 2.5rem;
  color: var(--primary-color);
  margin-bottom: 1rem;
}

.feature-card h4 {
  color: var(--text-primary);
  margin-bottom: 0.5rem;
  font-weight: 600;
}

.feature-card p {
  color: var(--text-secondary);
  font-size: 0.9rem;
  line-height: 1.5;
}

/* C++ Timeline */
.cpp-timeline {
  position: relative;
  margin: 2rem 0;
  padding: 1rem 0;
}

.cpp-timeline::before {
  content: '';
  position: absolute;
  left: 50%;
  top: 0;
  bottom: 0;
  width: 2px;
  background: var(--primary-color);
  transform: translateX(-50%);
}

.timeline-item {
  display: flex;
  margin-bottom: 2rem;
  position: relative;
}

/* Left side items */
.timeline-item-left {
  flex-direction: row;
  justify-content: flex-end;
}

.timeline-item-left .timeline-content {
  text-align: right;
  margin-right: 2rem;
}

/* Right side items */
.timeline-item-right {
  flex-direction: row-reverse;
  justify-content: flex-end;
}

.timeline-item-right .timeline-content {
  text-align: left;
  margin-left: 2rem;
}

/* Fallback for nth-child if classes aren't used */
.timeline-item:nth-child(odd):not(.timeline-item-right) {
  flex-direction: row;
  justify-content: flex-end;
}

.timeline-item:nth-child(odd):not(.timeline-item-right) .timeline-content {
  text-align: right;
  margin-right: 2rem;
  margin-left: 0;
}

.timeline-item:nth-child(even):not(.timeline-item-left) {
  flex-direction: row-reverse;
  justify-content: flex-end;
}

.timeline-item:nth-child(even):not(.timeline-item-left) .timeline-content {
  text-align: left;
  margin-left: 2rem;
  margin-right: 0;
}

.timeline-year {
  background: var(--primary-color);
  color: white;
  padding: 0.5rem 1rem;
  border-radius: 20px;
  font-weight: bold;
  font-size: 0.9rem;
  min-width: 80px;
  text-align: center;
  position: relative;
  z-index: 2;
}

.timeline-content {
  background: var(--bg-secondary);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-md);
  padding: 1rem;
  flex: 1;
  max-width: 300px;
}

.timeline-content h4 {
  color: var(--text-primary);
  margin-bottom: 0.5rem;
  font-size: 1rem;
}

.timeline-content p {
  color: var(--text-secondary);
  font-size: 0.85rem;
  margin: 0;
}

/* Skills Comparison */
.skills-comparison {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 2rem;
  margin: 2rem 0;
}

.prerequisite-column,
.skills-column {
  background: var(--bg-secondary);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-md);
  padding: 1.5rem;
}

.prerequisite-column h4,
.skills-column h4 {
  color: var(--text-primary);
  margin-bottom: 1rem;
  display: flex;
  align-items: center;
  gap: 0.5rem;
}

.prerequisite-column h4 i {
  color: var(--success-color);
}

.skills-column h4 i {
  color: var(--warning-color);
}

.prerequisite-column ul,
.skills-column ul {
  list-style: none;
  padding: 0;
  margin: 0;
}

.prerequisite-column li,
.skills-column li {
  color: var(--text-secondary);
  margin-bottom: 0.5rem;
  padding-left: 1.5rem;
  position: relative;
  font-size: 0.9rem;
}

.prerequisite-column li::before {
  content: "✓";
  position: absolute;
  left: 0;
  color: var(--success-color);
  font-weight: bold;
}

.skills-column li::before {
  content: "🎯";
  position: absolute;
  left: 0;
}

/* Applications Grid */
.applications-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
  gap: 1rem;
  margin: 2rem 0;
}

.application-card {
  background: var(--bg-secondary);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-md);
  padding: 1rem;
  text-align: center;
  transition: var(--transition);
}

.application-card:hover {
  transform: translateY(-3px);
  box-shadow: var(--shadow-md);
  border-color: var(--primary-color);
}

.application-card i {
  font-size: 1.8rem;
  color: var(--primary-color);
  margin-bottom: 0.5rem;
}

.application-card h4 {
  color: var(--text-primary);
  margin-bottom: 0.3rem;
  font-size: 0.9rem;
}

.application-card p {
  color: var(--text-secondary);
  font-size: 0.8rem;
  margin: 0;
}

/* Template Benefits */
.template-benefits {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(220px, 1fr));
  gap: 1.5rem;
  margin: 2rem 0;
}

.benefit-card {
  background: var(--bg-secondary);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-md);
  padding: 1.5rem;
  text-align: center;
  transition: var(--transition);
  position: relative;
}

.benefit-card::after {
  content: '';
  position: absolute;
  bottom: 0;
  left: 50%;
  width: 0;
  height: 3px;
  background: var(--primary-color);
  transition: var(--transition);
  transform: translateX(-50%);
}

.benefit-card:hover::after {
  width: 100%;
}

.benefit-card:hover {
  transform: translateY(-2px);
  box-shadow: var(--shadow-md);
}

.benefit-card i {
  font-size: 2rem;
  color: var(--primary-color);
  margin-bottom: 1rem;
}

.benefit-card h4 {
  color: var(--text-primary);
  margin-bottom: 0.5rem;
}

.benefit-card p {
  color: var(--text-secondary);
  font-size: 0.9rem;
}

/* Concept Explanation */
.concept-explanation {
  background: linear-gradient(135deg, var(--bg-secondary), var(--bg-tertiary));
  border: 1px solid var(--border-color);
  border-left: 4px solid var(--primary-color);
  border-radius: var(--radius-md);
  padding: 1.5rem;
  margin: 1.5rem 0;
}

.concept-explanation p {
  color: var(--text-secondary);
  margin: 0;
  font-style: italic;
}

/* Best Practices Grid */
.best-practices-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 2rem;
  margin: 2rem 0;
}

.practice-card {
  background: var(--bg-secondary);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-md);
  padding: 1.5rem;
}

.practice-card.avoid {
  border-left: 4px solid var(--error-color);
}

.practice-card:not(.avoid) {
  border-left: 4px solid var(--success-color);
}

.practice-card h4 {
  color: var(--text-primary);
  margin-bottom: 1rem;
  display: flex;
  align-items: center;
  gap: 0.5rem;
}

.practice-card:not(.avoid) h4 i {
  color: var(--success-color);
}

.practice-card.avoid h4 i {
  color: var(--error-color);
}

.practice-card ul {
  list-style: none;
  padding: 0;
  margin: 0;
}

.practice-card li {
  color: var(--text-secondary);
  margin-bottom: 0.5rem;
  padding-left: 1.5rem;
  position: relative;
  font-size: 0.9rem;
}

.practice-card:not(.avoid) li::before {
  content: "✓";
  position: absolute;
  left: 0;
  color: var(--success-color);
  font-weight: bold;
}

.practice-card.avoid li::before {
  content: "✗";
  position: absolute;
  left: 0;
  color: var(--error-color);
  font-weight: bold;
}

/* Performance Box */
.performance-box {
  background: linear-gradient(135deg, var(--primary-color-light), var(--secondary-color-light));
  border: 1px solid var(--primary-color);
  border-radius: var(--radius-md);
  padding: 1.5rem;
  margin: 1.5rem 0;
  position: relative;
  overflow: hidden;
}

.performance-box::before {
  content: '';
  position: absolute;
  top: -50%;
  right: -50%;
  width: 100%;
  height: 100%;
  background: radial-gradient(circle, rgba(255,255,255,0.1) 0%, transparent 70%);
  animation: performance-glow 3s ease-in-out infinite alternate;
}

@keyframes performance-glow {
  from { opacity: 0.5; }
  to { opacity: 1; }
}

.performance-box i {
  color: var(--primary-color);
  margin-right: 0.5rem;
}

.performance-box p {
  color: var(--text-primary);
  margin: 0;
  font-weight: 500;
  position: relative;
  z-index: 1;
}

/* Responsive adjustments for Advanced C++ components */
@media (max-width: 768px) {
  .advanced-features-grid,
  .template-benefits,
  .applications-grid {
    grid-template-columns: 1fr;
  }
  
  .skills-comparison,
  .best-practices-grid {
    grid-template-columns: 1fr;
  }
  
  .cpp-timeline::before {
    left: 20px;
  }
  
  .timeline-item,
  .timeline-item-left,
  .timeline-item-right {
    flex-direction: row !important;
    margin-left: 40px;
    justify-content: flex-start !important;
  }
  
  .timeline-item .timeline-content,
  .timeline-item-left .timeline-content,
  .timeline-item-right .timeline-content {
    text-align: left !important;
    margin-left: 1rem !important;
    margin-right: 0 !important;
  }
  
  .timeline-year {
    min-width: 60px;
    font-size: 0.8rem;
    padding: 0.3rem 0.5rem;
  }
  
  .feature-card,
  .benefit-card,
  .application-card {
    padding: 1rem;
  }
}

/* Smart Pointer Specific Styles */

/* Memory Evolution */
.memory-evolution {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
  gap: 1rem;
  margin: 2rem 0;
}

.evolution-step {
  background: var(--bg-secondary);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-md);
  padding: 1.5rem;
  text-align: center;
  transition: var(--transition);
}

.evolution-step:first-child {
  border-left: 4px solid var(--error-color);
}

.evolution-step:nth-child(2) {
  border-left: 4px solid var(--warning-color);
}

.evolution-step:last-child {
  border-left: 4px solid var(--success-color);
}

.evolution-step h4 {
  color: var(--text-primary);
  margin-bottom: 1rem;
  font-size: 1rem;
}

.evolution-step code {
  background: var(--bg-tertiary);
  color: var(--primary-color);
  padding: 0.5rem;
  border-radius: var(--radius-sm);
  font-family: 'Fira Code', monospace;
  display: block;
  margin: 0.5rem 0;
  font-size: 0.85rem;
}

.evolution-step p {
  color: var(--text-secondary);
  font-size: 0.9rem;
  margin: 0;
}

/* Smart Pointer Types */
.smart-pointer-types {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
  gap: 1.5rem;
  margin: 2rem 0;
}

.pointer-type-card {
  background: var(--bg-secondary);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-lg);
  padding: 2rem;
  text-align: center;
  transition: var(--transition);
  position: relative;
  overflow: hidden;
}

.pointer-type-card::before {
  content: '';
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  height: 4px;
  background: linear-gradient(90deg, var(--primary-color), var(--secondary-color));
}

.pointer-type-card:hover {
  transform: translateY(-5px);
  box-shadow: var(--shadow-lg);
  border-color: var(--primary-color);
}

.pointer-icon {
  font-size: 3rem;
  margin-bottom: 1rem;
  height: 80px;
  display: flex;
  align-items: center;
  justify-content: center;
}

.pointer-type-card h4 {
  color: var(--text-primary);
  margin-bottom: 0.5rem;
  font-size: 1.2rem;
}

.pointer-type-card p {
  color: var(--primary-color);
  font-weight: 600;
  margin-bottom: 1rem;
}

.pointer-type-card ul {
  list-style: none;
  padding: 0;
  margin: 0;
  text-align: left;
}

.pointer-type-card li {
  color: var(--text-secondary);
  margin-bottom: 0.5rem;
  padding-left: 1.2rem;
  position: relative;
  font-size: 0.9rem;
}

.pointer-type-card li::before {
  content: "▶";
  position: absolute;
  left: 0;
  color: var(--primary-color);
  font-size: 0.8rem;
}

/* Decision Tree */
.decision-tree {
  background: var(--bg-secondary);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-lg);
  padding: 2rem;
  margin: 2rem 0;
}

.decision-node h4 {
  color: var(--text-primary);
  text-align: center;
  margin-bottom: 2rem;
  font-size: 1.2rem;
}

.decision-branches {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
  gap: 1.5rem;
}

.decision-branch {
  text-align: center;
  padding: 1rem;
  background: var(--bg-tertiary);
  border-radius: var(--radius-md);
  border: 1px solid var(--border-color);
}

.condition {
  color: var(--text-primary);
  font-weight: 600;
  margin-bottom: 0.5rem;
}

.arrow {
  font-size: 1.5rem;
  color: var(--primary-color);
  margin: 0.5rem 0;
}

.result {
  background: var(--primary-color);
  color: white;
  padding: 0.5rem;
  border-radius: var(--radius-sm);
  margin-bottom: 0.5rem;
  font-weight: 600;
}

.result code {
  background: rgba(255,255,255,0.2);
  padding: 0.2rem 0.4rem;
  border-radius: 3px;
  font-family: 'Fira Code', monospace;
}

.example {
  color: var(--text-secondary);
  font-size: 0.8rem;
  font-style: italic;
}

/* Smart Pointer Patterns */
.smart-pointer-patterns {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
  gap: 1.5rem;
  margin: 2rem 0;
}

.pattern-card {
  background: var(--bg-secondary);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-md);
  padding: 1.5rem;
  transition: var(--transition);
}

.pattern-card:hover {
  transform: translateY(-2px);
  box-shadow: var(--shadow-md);
  border-color: var(--primary-color);
}

.pattern-card h4 {
  color: var(--text-primary);
  margin-bottom: 1rem;
  display: flex;
  align-items: center;
  gap: 0.5rem;
  font-size: 1rem;
}

.pattern-card h4 i {
  color: var(--primary-color);
}

.pattern-card code {
  background: var(--bg-tertiary);
  color: var(--primary-color);
  padding: 0.5rem;
  border-radius: var(--radius-sm);
  font-family: 'Fira Code', monospace;
  display: block;
  margin: 0.5rem 0;
  font-size: 0.85rem;
  overflow-x: auto;
}

.pattern-card p {
  color: var(--text-secondary);
  font-size: 0.9rem;
  margin: 0;
}

/* Performance Comparison Table */
.performance-comparison {
  margin: 2rem 0;
  overflow-x: auto;
}

.comparison-table {
  width: 100%;
  border-collapse: collapse;
  background: var(--bg-secondary);
  border-radius: var(--radius-md);
  overflow: hidden;
  box-shadow: var(--shadow-sm);
}

.comparison-table th,
.comparison-table td {
  padding: 1rem;
  text-align: left;
  border-bottom: 1px solid var(--border-color);
}

.comparison-table th {
  background: var(--primary-color);
  color: white;
  font-weight: 600;
  font-size: 0.9rem;
}

.comparison-table td {
  color: var(--text-secondary);
  font-size: 0.9rem;
}

.comparison-table td:first-child {
  color: var(--text-primary);
  font-weight: 600;
}

.comparison-table tr:hover {
  background: var(--bg-tertiary);
}

/* Enhanced Performance Table Styles */
.performance-table {
  margin: 2rem 0;
}

.performance-table h3,
.performance-table h4 {
  color: var(--text-primary);
  margin-bottom: 1rem;
  display: flex;
  align-items: center;
  gap: 0.5rem;
}

.performance-table h3 i,
.performance-table h4 i {
  color: var(--primary-color);
}

.table-container {
  overflow-x: auto;
  border-radius: var(--radius-md);
  box-shadow: var(--shadow-sm);
}

.comparison-table th i {
  margin-right: 0.3rem;
  opacity: 0.8;
}

/* Performance Badges */
.performance-badge {
  display: inline-block;
  padding: 0.25rem 0.5rem;
  border-radius: var(--radius-sm);
  font-size: 0.8rem;
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 0.5px;
}

.performance-badge.excellent {
  background: linear-gradient(135deg, #10b981, #059669);
  color: white;
}

.performance-badge.good {
  background: linear-gradient(135deg, #3b82f6, #2563eb);
  color: white;
}

.performance-badge.fair {
  background: linear-gradient(135deg, #f59e0b, #d97706);
  color: white;
}

.performance-badge.poor {
  background: linear-gradient(135deg, #ef4444, #dc2626);
  color: white;
}

/* Version Badges */
.version-badge {
  display: inline-block;
  padding: 0.2rem 0.4rem;
  border-radius: var(--radius-sm);
  font-size: 0.7rem;
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 0.3px;
  margin: 0 0.1rem;
}

.version-badge.cpp98 {
  background: linear-gradient(135deg, #6366f1, #4f46e5);
  color: white;
}

.version-badge.cpp11 {
  background: linear-gradient(135deg, #8b5cf6, #7c3aed);
  color: white;
}

.version-badge.cpp14 {
  background: linear-gradient(135deg, #ec4899, #db2777);
  color: white;
}

.version-badge.cpp17 {
  background: linear-gradient(135deg, #f97316, #ea580c);
  color: white;
}

.version-badge.cpp20 {
  background: linear-gradient(135deg, #06b6d4, #0891b2);
  color: white;
}

/* Code styling in tables */
.comparison-table code {
  background: var(--bg-tertiary);
  padding: 0.2rem 0.4rem;
  border-radius: var(--radius-sm);
  font-family: var(--font-mono);
  font-size: 0.8rem;
  color: var(--primary-color);
  border: 1px solid var(--border-color);
}

.comparison-table small {
  color: var(--text-muted);
  font-style: italic;
}

/* Responsive table design */
@media (max-width: 768px) {
  .table-container {
    font-size: 0.8rem;
  }
  
  .comparison-table th,
  .comparison-table td {
    padding: 0.5rem;
  }
  
  .performance-badge,
  .version-badge {
    font-size: 0.6rem;
    padding: 0.15rem 0.3rem;
  }
  
  .comparison-table code {
    font-size: 0.7rem;
    padding: 0.1rem 0.3rem;
  }
  
  .performance-table h3,
  .performance-table h4 {
    font-size: 1.1rem;
  }
}

@media (max-width: 480px) {
  .comparison-table th i {
    display: none;
  }
  
  .performance-table h3 i,
  .performance-table h4 i {
    display: none;
  }
}

/* Warning Box */
.warning-box {
  background: linear-gradient(135deg, var(--warning-light), var(--warning-lighter));
  border: 1px solid var(--warning-color);
  border-radius: var(--radius-md);
  padding: 1.5rem;
  margin: 1.5rem 0;
}

.warning-box i {
  color: var(--warning-color);
  margin-right: 0.5rem;
  font-size: 1.2rem;
}

.warning-box p {
  color: var(--text-primary);
  margin: 0 0 1rem 0;
  font-weight: 600;
}

.warning-box ul {
  list-style: none;
  padding: 0;
  margin: 0;
}

.warning-box li {
  color: var(--text-secondary);
  margin-bottom: 0.5rem;
  padding-left: 1.5rem;
  position: relative;
}

.warning-box li::before {
  content: "⚠";
  position: absolute;
  left: 0;
  color: var(--warning-color);
}

.warning-box code {
  background: rgba(255,255,255,0.8);
  color: var(--warning-dark);
  padding: 0.2rem 0.4rem;
  border-radius: 3px;
  font-family: 'Fira Code', monospace;
  font-size: 0.85rem;
}

/* Responsive adjustments for smart pointer components */
@media (max-width: 768px) {
  .memory-evolution,
  .smart-pointer-types,
  .smart-pointer-patterns {
    grid-template-columns: 1fr;
  }
  
  .decision-branches {
    grid-template-columns: 1fr;
  }
  
  .performance-comparison {
    font-size: 0.8rem;
  }
  
  .comparison-table th,
  .comparison-table td {
    padding: 0.5rem;
  }
}

/* Metaprogramming Concepts */
.metaprogramming-concepts {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
  gap: 1.5rem;
  margin: 2rem 0;
}

.concept-card {
  background: var(--bg-secondary);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-md);
  padding: 1.5rem;
  text-align: center;
  transition: var(--transition);
  position: relative;
  overflow: hidden;
}

.concept-card::before {
  content: '';
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  height: 3px;
  background: linear-gradient(90deg, var(--primary-color), var(--secondary-color));
}

.concept-card:hover {
  transform: translateY(-3px);
  box-shadow: var(--shadow-md);
  border-color: var(--primary-color);
}

.concept-card h4 {
  color: var(--text-primary);
  margin-bottom: 0.5rem;
  font-size: 1rem;
}

.concept-card p {
  color: var(--text-secondary);
  font-size: 0.9rem;
  margin: 0;
}

/* Best Practices Grid */
.practices-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
  gap: 2rem;
  margin: 2rem 0;
}

.practice-category {
  background: var(--bg-secondary);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-lg);
  padding: 2rem;
  transition: var(--transition);
}

.practice-category:nth-child(1) {
  border-left: 4px solid var(--primary-color);
}

.practice-category:nth-child(2) {
  border-left: 4px solid var(--success-color);
}

.practice-category:nth-child(3) {
  border-left: 4px solid var(--warning-color);
}

.practice-category:nth-child(4) {
  border-left: 4px solid var(--secondary-color);
}

.practice-category:hover {
  transform: translateY(-2px);
  box-shadow: var(--shadow-md);
}

.practice-category h4 {
  color: var(--text-primary);
  margin-bottom: 1.5rem;
  display: flex;
  align-items: center;
  gap: 0.5rem;
  font-size: 1.1rem;
}

.practice-category:nth-child(1) h4 i {
  color: var(--primary-color);
}

.practice-category:nth-child(2) h4 i {
  color: var(--success-color);
}

.practice-category:nth-child(3) h4 i {
  color: var(--warning-color);
}

.practice-category:nth-child(4) h4 i {
  color: var(--secondary-color);
}

.practice-category ul {
  list-style: none;
  padding: 0;
  margin: 0;
}

.practice-category li {
  color: var(--text-secondary);
  margin-bottom: 0.8rem;
  padding-left: 1.5rem;
  position: relative;
  font-size: 0.9rem;
  line-height: 1.4;
}

.practice-category li::before {
  content: "✓";
  position: absolute;
  left: 0;
  color: var(--success-color);
  font-weight: bold;
}

/* Additional responsive styles for new components */
@media (max-width: 768px) {
  .metaprogramming-concepts,
  .practices-grid {
    grid-template-columns: 1fr;
  }
  
  .practice-category {
    padding: 1.5rem;
  }
}

/* Exception Handling Styles */
.exception-principles {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: 1rem;
    margin: 1.5rem 0;
}

.principle-card {
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    color: white;
    padding: 1.5rem;
    border-radius: 10px;
    text-align: center;
    box-shadow: 0 4px 15px rgba(102, 126, 234, 0.3);
    transition: transform 0.3s ease;
}

.principle-card:hover {
    transform: translateY(-5px);
}

.principle-card h4 {
    margin: 0 0 0.5rem 0;
    font-size: 1.1rem;
}

.principle-card p {
    margin: 0;
    font-size: 0.9rem;
    opacity: 0.9;
}

.safety-levels {
    display: flex;
    gap: 1rem;
    margin: 1.5rem 0;
    flex-wrap: wrap;
}

.safety-level {
    flex: 1;
    min-width: 200px;
    padding: 1.5rem;
    border-radius: 10px;
    text-align: center;
    color: white;
    font-weight: 500;
}

.safety-level.basic {
    background: linear-gradient(135deg, #f093fb 0%, #f5576c 100%);
}

.safety-level.strong {
    background: linear-gradient(135deg, #4facfe 0%, #00f2fe 100%);
}

.safety-level.nothrow {
    background: linear-gradient(135deg, #43e97b 0%, #38f9d7 100%);
}

.safety-level h4 {
    margin: 0 0 0.5rem 0;
    font-size: 1.2rem;
}

.safety-level p {
    margin: 0;
    font-size: 0.9rem;
    opacity: 0.9;
}

.exception-best-practices {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 2rem;
    margin: 2rem 0;
}

.exception-best-practices .practice-category {
    background: var(--card-bg);
    border-radius: 10px;
    padding: 1.5rem;
    border-left: 4px solid var(--primary-color);
}

.exception-best-practices .practice-category.do {
    border-left-color: #28a745;
}

.exception-best-practices .practice-category.dont {
    border-left-color: #dc3545;
}

.exception-best-practices .practice-category h4 {
    margin: 0 0 1rem 0;
    color: var(--text-color);
}

.exception-best-practices .practice-category.do h4 {
    color: #28a745;
}

.exception-best-practices .practice-category.dont h4 {
    color: #dc3545;
}

.exception-best-practices .practice-category ul {
    margin: 0;
    padding-left: 1.5rem;
}

.exception-best-practices .practice-category li {
    margin-bottom: 0.5rem;
    color: var(--text-muted);
}

/* Design Patterns Styles */
.pattern-categories {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
    gap: 1.5rem;
    margin: 2rem 0;
}

.pattern-categories .pattern-category {
    background: var(--card-bg);
    border-radius: 10px;
    padding: 1.5rem;
    text-align: center;
    border: 2px solid transparent;
    transition: all 0.3s ease;
}

.pattern-categories .pattern-category:hover {
    border-color: var(--primary-color);
    transform: translateY(-5px);
    box-shadow: 0 10px 25px rgba(0, 0, 0, 0.1);
}

.pattern-categories .pattern-category i {
    font-size: 2.5rem;
    color: var(--primary-color);
    margin-bottom: 1rem;
    display: block;
}

.pattern-categories .pattern-category h4 {
    margin: 0 0 0.5rem 0;
    color: var(--text-color);
}

.pattern-categories .pattern-category p {
    margin: 0;
    color: var(--text-muted);
    font-size: 0.9rem;
}

.pattern-guide {
    background: var(--card-bg);
    border-radius: 10px;
    padding: 2rem;
    margin: 2rem 0;
}

.guide-row {
    display: flex;
    align-items: center;
    justify-content: space-between;
    padding: 1rem 0;
    border-bottom: 1px solid var(--border-color);
}

.guide-row:last-child {
    border-bottom: none;
}

.guide-row .use-case {
    flex: 1;
    font-weight: 500;
    color: var(--text-color);
}

.guide-row .arrow {
    font-size: 1.5rem;
    color: var(--primary-color);
    margin: 0 1rem;
}

.guide-row .pattern {
    flex: 1;
    text-align: right;
    background: var(--primary-color);
    color: white;
    padding: 0.5rem 1rem;
    border-radius: 20px;
    font-weight: 500;
    font-size: 0.9rem;
}

/* Performance Optimization Styles */
.performance-principles {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
    gap: 1.5rem;
    margin: 2rem 0;
}

.optimization-checklist {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: 2rem;
    margin: 2rem 0;
}

.optimization-checklist .checklist-category {
    background: var(--card-bg);
    border-radius: 10px;
    padding: 1.5rem;
    border-left: 4px solid var(--primary-color);
}

.optimization-checklist .checklist-category h4 {
    margin: 0 0 1rem 0;
    color: var(--primary-color);
    display: flex;
    align-items: center;
    gap: 0.5rem;
}

.optimization-checklist .checklist-category ul {
    margin: 0;
    padding-left: 1.5rem;
}

.optimization-checklist .checklist-category li {
    margin-bottom: 0.5rem;
    color: var(--text-muted);
    line-height: 1.4;
}

.comparison-table {
    width: 100%;
    border-collapse: collapse;
    margin: 2rem 0;
    background: var(--card-bg);
    border-radius: 10px;
    overflow: hidden;
    box-shadow: 0 4px 15px rgba(0, 0, 0, 0.1);
}

.comparison-table th,
.comparison-table td {
    padding: 1rem;
    text-align: left;
    border-bottom: 1px solid var(--border-color);
}

.comparison-table th {
    background: var(--primary-color);
    color: white;
    font-weight: 600;
}

.comparison-table tr:nth-child(even) {
    background: rgba(0, 0, 0, 0.02);
}

.comparison-table tr:hover {
    background: rgba(var(--primary-color-rgb), 0.1);
}

.comparison-table td strong {
    color: var(--primary-color);
}

/* Enhanced responsive adjustments */
@media (max-width: 768px) {
    .exception-best-practices {
        grid-template-columns: 1fr;
        gap: 1rem;
    }
    
    .safety-levels {
        flex-direction: column;
        gap: 1rem;
    }
    
    .guide-row {
        flex-direction: column;
        align-items: flex-start;
        gap: 0.5rem;
    }
    
    .guide-row .pattern {
        text-align: left;
        align-self: stretch;
    }
    
    .comparison-table {
        font-size: 0.8rem;
    }
    
    .comparison-table th,
    .comparison-table td {
        padding: 0.5rem;
    }
    
    .exception-principles,
    .pattern-categories,
    .performance-principles,
    .optimization-checklist {
        grid-template-columns: 1fr;
    }
}

/* Dark mode adjustments */
[data-theme="dark"] .principle-card,
[data-theme="dark"] .safety-level {
    box-shadow: 0 4px 15px rgba(0, 0, 0, 0.3);
}

[data-theme="dark"] .comparison-table tr:nth-child(even) {
    background: rgba(255, 255, 255, 0.02);
}

[data-theme="dark"] .comparison-table tr:hover {
    background: rgba(var(--primary-color-rgb), 0.15);
}

[data-theme="dark"] .pattern-categories .pattern-category:hover {
    box-shadow: 0 10px 25px rgba(0, 0, 0, 0.3);
}

/* Global overflow prevention */
body, html {
  overflow-x: hidden;
}

*:not(pre):not(code) {
  overflow-wrap: break-word;
  word-wrap: break-word;
}

/* Ensure all containers stay within viewport */
.container, .main-content, .content-section, .accordion-content, .topic-content, .code-block, .project-features {
  max-width: 100%;
  overflow-x: hidden;
  box-sizing: border-box;
}

/* Make pre elements responsive */
pre {
  overflow-x: auto;
  white-space: pre-wrap;
  word-wrap: break-word;
  max-width: 100%;
  font-size: 0.75rem;
}

@media (max-width: 768px) {
  pre {
    font-size: 0.7rem;
    padding: 1rem;
  }
  
  .main-content {
    padding: 1rem;
  }
  
  .topic-content {
    padding: 1rem;
  }
}