@import url('https://fonts.googleapis.com/css2?family=Inter:wght@400;500;600;700;800;900&family=JetBrains+Mono:wght@400;500;600&display=swap');

:root {
  --primary-gradient: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
  --secondary-gradient: linear-gradient(135deg, #f093fb 0%, #f5576c 100%);
  --success-gradient: linear-gradient(135deg, #4facfe 0%, #00f2fe 100%);
  
  --primary-color: #667eea;
  --primary-dark: #5a67d8;
  --primary-light: #7c8ef8;
  --accent-color: #f5576c;
  --success-color: #00f2fe;
  --warning-color: #f093fb;
  --error-color: #ff6b6b;

  --bg-primary: #0a0a0a;
  --bg-secondary: #141414;
  --bg-card: #1a1a1a;
  --bg-code: #0d0d0d;

  --text-primary: #ffffff;
  --text-secondary: #a0a0a0;
  --text-muted: #707070;
  --text-light: #ffffff;

  --border-color: #2a2a2a;
  --border-hover: #4a4a4a;

  --glass-bg: rgba(26, 26, 26, 0.8);
  --glass-border: rgba(255, 255, 255, 0.1);

  --shadow-sm: 0 2px 8px rgba(0, 0, 0, 0.3);
  --shadow-md: 0 4px 16px rgba(0, 0, 0, 0.4);
  --shadow-lg: 0 8px 32px rgba(0, 0, 0, 0.5);
  --shadow-xl: 0 16px 64px rgba(102, 126, 234, 0.3);

  --transition-fast: 0.2s cubic-bezier(0.4, 0, 0.2, 1);
  --transition-normal: 0.3s cubic-bezier(0.4, 0, 0.2, 1);
  --transition-slow: 0.5s cubic-bezier(0.4, 0, 0.2, 1);

  --radius-sm: 0.5rem;
  --radius-md: 0.75rem;
  --radius-lg: 1rem;
  --radius-xl: 1.5rem;

  --font-primary: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
  --font-mono: 'JetBrains Mono', 'Menlo', 'Monaco', 'Courier New', monospace;
}

[data-theme="light"] {
  --bg-primary: #f8f9fa;
  --bg-secondary: #ffffff;
  --bg-card: #ffffff;
  --bg-code: #1a1a2e;

  --text-primary: #1a1a2e;
  --text-secondary: #4a4a4a;
  --text-muted: #7a7a7a;

  --border-color: #e0e0e0;
  --border-hover: #c0c0c0;

  --glass-bg: rgba(255, 255, 255, 0.9);
  --glass-border: rgba(0, 0, 0, 0.1);
}

* {
  margin: 0;
  padding: 0;
  box-sizing: border-box;
}

html {
  font-size: 16px;
  scroll-behavior: smooth;
}

body {
  font-family: var(--font-primary);
  background: var(--bg-primary);
  color: var(--text-primary);
  line-height: 1.6;
  overflow-x: hidden;
  transition: background var(--transition-normal), color var(--transition-normal);
}

/* 动态背景 */
body::before {
  content: '';
  position: fixed;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  background: 
    radial-gradient(circle at 20% 80%, rgba(102, 126, 234, 0.15) 0%, transparent 50%),
    radial-gradient(circle at 80% 20%, rgba(245, 87, 108, 0.15) 0%, transparent 50%),
    radial-gradient(circle at 40% 40%, rgba(0, 242, 254, 0.1) 0%, transparent 50%);
  z-index: -1;
  animation: gradientShift 15s ease infinite;
}

@keyframes gradientShift {
  0%, 100% { transform: scale(1) rotate(0deg); }
  50% { transform: scale(1.1) rotate(5deg); }
}

.container {
  display: flex;
  min-height: 100vh;
}

.sidebar {
  width: 280px;
  background: var(--glass-bg);
  backdrop-filter: blur(20px);
  -webkit-backdrop-filter: blur(20px);
  border-right: 1px solid var(--glass-border);
  position: fixed;
  height: 100vh;
  overflow-y: auto;
  display: flex;
  flex-direction: column;
  transition: transform var(--transition-normal), background var(--transition-normal);
  z-index: 100;
}

.sidebar-header {
  padding: 2rem 1.5rem;
  border-bottom: 1px solid var(--glass-border);
  background: var(--primary-gradient);
  position: relative;
  overflow: hidden;
}

.sidebar-header::before {
  content: '';
  position: absolute;
  top: -50%;
  left: -50%;
  width: 200%;
  height: 200%;
  background: linear-gradient(45deg, transparent, rgba(255, 255, 255, 0.1), transparent);
  animation: shimmer 3s infinite;
}

@keyframes shimmer {
  0% { transform: translateX(-100%) rotate(45deg); }
  100% { transform: translateX(100%) rotate(45deg); }
}

.sidebar-header h1 {
  font-size: 1.75rem;
  font-weight: 900;
  margin-bottom: 0.375rem;
  letter-spacing: -0.025em;
  position: relative;
  z-index: 1;
}

.subtitle {
  font-size: 0.9375rem;
  opacity: 0.95;
  font-weight: 500;
  letter-spacing: 0.025em;
  position: relative;
  z-index: 1;
}

.sidebar-nav {
  flex: 1;
  padding: 1rem 0;
}

.nav-list {
  list-style: none;
}

.nav-item {
  margin: 0.25rem 0;
}

.nav-link {
  display: flex;
  align-items: center;
  gap: 0.75rem;
  padding: 0.875rem 1.5rem;
  color: var(--text-secondary);
  text-decoration: none;
  transition: all var(--transition-fast);
  border-left: 3px solid transparent;
  font-weight: 500;
  font-size: 0.9375rem;
  line-height: 1.5;
  letter-spacing: 0.00625em;
  border-radius: 0 var(--radius-sm) var(--radius-sm) 0;
  margin-right: 1rem;
}

.nav-link:hover {
  background: var(--bg-card);
  color: var(--primary-color);
  border-left-color: var(--primary-color);
  transform: translateX(4px);
}

.nav-link.active {
  background: var(--primary-gradient);
  color: white;
  border-left-color: white;
  font-weight: 700;
  box-shadow: var(--shadow-md);
  transform: translateX(0);
}

.nav-icon {
  font-size: 1.25rem;
  width: 1.5rem;
  text-align: center;
}

.sidebar-footer {
  padding: 1.5rem;
  border-top: 1px solid var(--glass-border);
  background: var(--glass-bg);
  backdrop-filter: blur(20px);
  -webkit-backdrop-filter: blur(20px);
}

.progress-bar {
  height: 6px;
  background: var(--bg-card);
  border-radius: var(--radius-sm);
  overflow: hidden;
  margin-bottom: 0.75rem;
  box-shadow: inset 0 2px 4px rgba(0, 0, 0, 0.2);
}

.progress-fill {
  height: 100%;
  background: var(--success-gradient);
  border-radius: var(--radius-sm);
  transition: width var(--transition-slow);
  width: 0%;
  position: relative;
  overflow: hidden;
}

.progress-fill::after {
  content: '';
  position: absolute;
  top: 0;
  left: -100%;
  width: 100%;
  height: 100%;
  background: linear-gradient(90deg, transparent, rgba(255, 255, 255, 0.4), transparent);
  animation: progressShimmer 2s infinite;
}

@keyframes progressShimmer {
  0% { left: -100%; }
  100% { left: 100%; }
}

.progress-text {
  font-size: 0.8125rem;
  color: var(--text-secondary);
  font-weight: 600;
  letter-spacing: 0.025em;
}

.main-content {
  flex: 1;
  margin-left: 280px;
  padding: 2rem 3rem 2rem 3rem;
  max-width: 1200px;
}

.mobile-menu-toggle {
  display: none;
  position: fixed;
  top: 1rem;
  left: 1rem;
  width: 3rem;
  height: 3rem;
  border-radius: var(--radius-md);
  background: var(--primary-gradient);
  border: none;
  cursor: pointer;
  z-index: 1000;
  box-shadow: var(--shadow-lg);
  transition: all var(--transition-fast);
  align-items: center;
  justify-content: center;
  color: white;
  font-size: 1.25rem;
}

.mobile-menu-toggle:hover {
  transform: scale(1.05);
  box-shadow: var(--shadow-xl);
}

.mobile-menu-toggle:active {
  transform: scale(0.95);
}

.menu-icon {
  font-size: 1.25rem;
}

.content-wrapper {
  display: flex;
  flex-direction: column;
  gap: 1.75rem;
}

.section {
  display: none;
  animation: sectionFadeIn var(--transition-normal);
}

.section.active {
  display: block;
}

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

.section-header {
  display: flex;
  align-items: center;
  gap: 1rem;
  margin-bottom: 1.5rem;
  padding-bottom: 1rem;
  border-bottom: 2px solid var(--border-color);
}

.section-title {
  font-size: 2.5rem;
  font-weight: 800;
  color: var(--text-primary);
  letter-spacing: -0.025em;
  background: var(--primary-gradient);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}

.section-badge {
  padding: 0.375rem 0.875rem;
  background: var(--secondary-gradient);
  color: white;
  font-size: 0.8125rem;
  font-weight: 700;
  border-radius: var(--radius-sm);
  text-transform: uppercase;
  letter-spacing: 0.05em;
  box-shadow: var(--shadow-sm);
}

.card {
  background: var(--glass-bg);
  backdrop-filter: blur(20px);
  -webkit-backdrop-filter: blur(20px);
  border-radius: var(--radius-lg);
  padding: 2rem;
  box-shadow: var(--shadow-md);
  border: 1px solid var(--glass-border);
  transition: all var(--transition-normal);
  margin-bottom: 1.5rem;
  position: relative;
  overflow: hidden;
}

.card::before {
  content: '';
  position: absolute;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  background: linear-gradient(135deg, rgba(102, 126, 234, 0.05) 0%, transparent 50%);
  opacity: 0;
  transition: opacity var(--transition-normal);
}

.card:hover {
  box-shadow: var(--shadow-xl);
  transform: translateY(-4px);
  border-color: var(--primary-color);
}

.card:hover::before {
  opacity: 1;
}

.card h3 {
  font-size: 1.5rem;
  font-weight: 700;
  color: var(--text-primary);
  margin-bottom: 1rem;
  display: flex;
  align-items: center;
  gap: 0.75rem;
  letter-spacing: -0.0125em;
  position: relative;
  z-index: 1;
}

.card h3::before {
  content: '';
  width: 4px;
  height: 1.5rem;
  background: var(--primary-gradient);
  border-radius: var(--radius-sm);
}

.card p {
  color: var(--text-secondary);
  margin-bottom: 1rem;
  line-height: 1.8;
  font-size: 1.0625rem;
  letter-spacing: 0.00625em;
  position: relative;
  z-index: 1;
}

.feature-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(240px, 1fr));
  gap: 1.25rem;
  margin-top: 1.5rem;
}

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

.feature-item::before {
  content: '';
  position: absolute;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  background: var(--primary-gradient);
  opacity: 0;
  transition: opacity var(--transition-normal);
}

.feature-item:hover {
  border-color: var(--primary-color);
  transform: translateY(-8px) scale(1.02);
  box-shadow: var(--shadow-xl);
}

.feature-item:hover::before {
  opacity: 0.1;
}

.feature-icon {
  font-size: 2.5rem;
  margin-bottom: 1rem;
  position: relative;
  z-index: 1;
}

.feature-item h4 {
  font-size: 1.125rem;
  font-weight: 700;
  color: var(--text-primary);
  margin-bottom: 0.625rem;
  letter-spacing: -0.00625em;
  position: relative;
  z-index: 1;
}

.feature-item p {
  font-size: 0.9375rem;
  color: var(--text-secondary);
  margin: 0;
  line-height: 1.6;
  letter-spacing: 0.00625em;
  position: relative;
  z-index: 1;
}

.code-block {
  background: var(--bg-code);
  border-radius: var(--radius-lg);
  overflow: hidden;
  margin: 1.5rem 0;
  box-shadow: var(--shadow-lg);
  border: 1px solid var(--border-color);
  position: relative;
}

.code-header {
  display: flex;
  justify-content: space-between;
  align-items: center;
  padding: 0.75rem 1rem;
  background: rgba(255, 255, 255, 0.05);
  border-bottom: 1px solid var(--border-color);
  gap: 0.5rem;
}

.code-header-left {
  display: flex;
  align-items: center;
  gap: 0.75rem;
}

.code-header span {
  color: var(--text-secondary);
  font-size: 0.8125rem;
  font-weight: 600;
  font-family: var(--font-mono);
  letter-spacing: 0.0125em;
}

.code-header-actions {
  display: flex;
  align-items: center;
  gap: 0.5rem;
}

.collapse-btn {
  background: rgba(255, 255, 255, 0.1);
  color: var(--text-secondary);
  border: 1px solid var(--border-color);
  padding: 0.375rem 0.75rem;
  border-radius: var(--radius-sm);
  font-size: 0.75rem;
  font-weight: 600;
  cursor: pointer;
  transition: all var(--transition-fast);
  font-family: var(--font-primary);
  letter-spacing: 0.0125em;
  display: flex;
  align-items: center;
  gap: 0.375rem;
}

.collapse-btn:hover {
  background: rgba(255, 255, 255, 0.2);
  color: var(--text-primary);
  border-color: var(--border-hover);
}

.collapse-btn .arrow {
  transition: transform var(--transition-fast);
}

.collapse-btn.collapsed .arrow {
  transform: rotate(-90deg);
}

.copy-btn {
  background: var(--primary-gradient);
  color: white;
  border: none;
  padding: 0.375rem 0.75rem;
  border-radius: var(--radius-sm);
  font-size: 0.8125rem;
  font-weight: 600;
  cursor: pointer;
  transition: all var(--transition-fast);
  font-family: var(--font-primary);
  letter-spacing: 0.0125em;
  box-shadow: var(--shadow-sm);
}

.copy-btn:hover {
  transform: scale(1.05);
  box-shadow: var(--shadow-md);
}

.copy-btn:active {
  transform: scale(0.95);
}

.code-block pre {
  padding: 1.5rem;
  overflow-x: auto;
  margin: 0;
  transition: max-height var(--transition-normal), opacity var(--transition-normal), padding var(--transition-normal);
  max-height: 500px;
}

.code-block.collapsed pre {
  max-height: 0;
  padding-top: 0;
  padding-bottom: 0;
  opacity: 0;
  overflow: hidden;
}

.code-block .expand-hint {
  text-align: center;
  padding: 0.5rem;
  color: var(--text-muted);
  font-size: 0.75rem;
  cursor: pointer;
  transition: all var(--transition-fast);
  border-top: 1px solid var(--border-color);
  display: none;
}

.code-block.collapsed .expand-hint {
  display: block;
}

.code-block .expand-hint:hover {
  color: var(--primary-color);
  background: rgba(102, 126, 234, 0.05);
}

.code-block code {
  font-family: var(--font-mono);
  font-size: 0.9375rem;
  line-height: 1.8;
  color: #e2e8f0;
  letter-spacing: 0;
}

.comparison-table {
  overflow-x: auto;
  margin: 2rem 0;
  border-radius: var(--radius-lg);
  box-shadow: var(--shadow-md);
}

.comparison-table table {
  width: 100%;
  border-collapse: collapse;
  font-size: 0.9375rem;
  background: var(--bg-card);
  border-radius: var(--radius-lg);
  overflow: hidden;
}

.comparison-table th,
.comparison-table td {
  padding: 1rem 1.25rem;
  text-align: left;
  border-bottom: 1px solid var(--border-color);
  border-right: 1px solid var(--border-color);
  line-height: 1.6;
  letter-spacing: 0.00625em;
}

.comparison-table th:last-child,
.comparison-table td:last-child {
  border-right: none;
}

.comparison-table th {
  background: var(--primary-gradient);
  font-weight: 700;
  color: white;
  position: sticky;
  top: 0;
  padding: 1.125rem 1.25rem;
  letter-spacing: 0.0125em;
}

.comparison-table tr:hover td {
  background: rgba(102, 126, 234, 0.1);
}

.comparison-table .highlight {
  background: rgba(102, 126, 234, 0.2);
  color: var(--primary-color);
  font-weight: 700;
}

.feature-list {
  list-style: none;
  padding: 0;
}

.feature-list li {
  padding: 0.75rem 0;
  padding-left: 1.5rem;
  position: relative;
  color: var(--text-secondary);
  line-height: 1.8;
  font-size: 1.0625rem;
  letter-spacing: 0.00625em;
  font-weight: 400;
}

.feature-list li::before {
  content: '✓';
  position: absolute;
  left: 0;
  color: var(--success-color);
  font-weight: 800;
  font-size: 1.125rem;
}

.feature-list li strong {
  color: var(--text-primary);
  font-weight: 700;
}

.theme-toggle {
  position: fixed;
  bottom: 1.5rem;
  right: 1.5rem;
  width: 3rem;
  height: 3rem;
  border-radius: 50%;
  background: var(--primary-gradient);
  border: none;
  cursor: pointer;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 1.25rem;
  box-shadow: var(--shadow-lg);
  transition: all var(--transition-fast);
  z-index: 1000;
}

.theme-toggle:hover {
  transform: scale(1.1) rotate(15deg);
  box-shadow: var(--shadow-xl);
}

.theme-icon {
  font-size: 1.25rem;
}

.theme-toggle:active {
  transform: scale(0.95);
}

@media (max-width: 1024px) {
  .mobile-menu-toggle {
    display: flex;
  }

  .sidebar {
    transform: translateX(-100%);
  }

  .sidebar.open {
    transform: translateX(0);
  }

  .main-content {
    margin-left: 0;
    padding: 1.5rem;
    padding-top: 5rem;
  }

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

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

@media (max-width: 768px) {
  .card {
    padding: 1.5rem;
  }

  .code-block pre {
    padding: 1.25rem;
    font-size: 0.875rem;
  }

  .theme-toggle {
    bottom: 1rem;
    right: 1rem;
    width: 2.5rem;
    height: 2.5rem;
  }

  .comparison-table {
    font-size: 0.875rem;
  }

  .comparison-table th,
  .comparison-table td {
    padding: 0.75rem 1rem;
  }

  .section-title {
    font-size: 1.75rem;
  }
}

@media (max-width: 480px) {
  .main-content {
    padding: 1rem;
  }

  .section-title {
    font-size: 1.5rem;
  }

  .section-header {
    flex-direction: column;
    align-items: flex-start;
  }

  .card {
    padding: 1.25rem;
  }

  .feature-item {
    padding: 1.25rem;
  }
}

::-webkit-scrollbar {
  width: 8px;
  height: 8px;
}

::-webkit-scrollbar-track {
  background: var(--bg-secondary);
}

::-webkit-scrollbar-thumb {
  background: var(--border-color);
  border-radius: var(--radius-sm);
}

::-webkit-scrollbar-thumb:hover {
  background: var(--border-hover);
}

@media (prefers-reduced-motion: reduce) {
  * {
    animation-duration: 0.01ms !important;
    animation-iteration-count: 1 !important;
    transition-duration: 0.01ms !important;
  }
}

.print-only {
  display: none;
}

@media print {
  .sidebar,
  .theme-toggle {
    display: none;
  }
  
  .main-content {
    margin-left: 0;
    padding: 0;
  }
  
  .card {
    box-shadow: none;
    border: 1px solid #000;
  }
  
  .code-block {
    background: #fff;
    border: 1px solid #000;
  }
  
  .code-block code {
    color: #000;
  }
  
  a {
    text-decoration: underline;
  }
}