/* ============================================
   PCB Design Knowledge Base - Stylesheet
   ============================================ */

/* CSS Variables */
:root {
  /* Colors - Light Theme */
  --primary-color: #2563eb;
  --primary-dark: #1d4ed8;
  --primary-light: #3b82f6;
  --secondary-color: #0ea5e9;
  --accent-color: #06b6d4;
  
  --bg-color: #f8fafc;
  --bg-secondary: #f1f5f9;
  --bg-card: #ffffff;
  --bg-sidebar: #1e293b;
  --bg-sidebar-hover: #334155;
  
  --text-primary: #1e293b;
  --text-secondary: #475569;
  --text-muted: #94a3b8;
  --text-light: #e2e8f0;
  
  --border-color: #e2e8f0;
  --border-light: #f1f5f9;
  
  --success-color: #10b981;
  --warning-color: #f59e0b;
  --error-color: #ef4444;
  --info-color: #3b82f6;
  
  /* Shadows */
  --shadow-sm: 0 1px 2px 0 rgb(0 0 0 / 0.05);
  --shadow-md: 0 4px 6px -1px rgb(0 0 0 / 0.1);
  --shadow-lg: 0 10px 15px -3px rgb(0 0 0 / 0.1);
  
  /* Spacing */
  --spacing-xs: 0.25rem;
  --spacing-sm: 0.5rem;
  --spacing-md: 1rem;
  --spacing-lg: 1.5rem;
  --spacing-xl: 2rem;
  --spacing-2xl: 3rem;
  
  /* Layout */
  --sidebar-width: 280px;
  --header-height: 60px;
  --content-max-width: 1200px;
  
  /* Typography */
  --font-sans: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial, sans-serif;
  --font-mono: "SFMono-Regular", Consolas, "Liberation Mono", Menlo, monospace;
  
  /* Transitions */
  --transition-fast: 150ms ease;
  --transition-normal: 250ms ease;
  --transition-slow: 350ms ease;
  
  /* Border Radius */
  --radius-sm: 4px;
  --radius-md: 8px;
  --radius-lg: 12px;
  --radius-full: 9999px;
}

/* Dark Theme */
[data-theme="dark"] {
  --bg-color: #0f172a;
  --bg-secondary: #1e293b;
  --bg-card: #1e293b;
  --bg-sidebar: #020617;
  --bg-sidebar-hover: #1e293b;
  
  --text-primary: #f1f5f9;
  --text-secondary: #cbd5e1;
  --text-muted: #64748b;
  --text-light: #94a3b8;
  
  --border-color: #334155;
  --border-light: #1e293b;
  
  --shadow-sm: 0 1px 2px 0 rgb(0 0 0 / 0.3);
  --shadow-md: 0 4px 6px -1px rgb(0 0 0 / 0.4);
  --shadow-lg: 0 10px 15px -3px rgb(0 0 0 / 0.4);
}

/* Reset & Base */
*, *::before, *::after {
  box-sizing: border-box;
  margin: 0;
  padding: 0;
}

html {
  scroll-behavior: smooth;
  scroll-padding-top: calc(var(--header-height) + var(--spacing-lg));
}

body {
  font-family: var(--font-sans);
  font-size: 16px;
  line-height: 1.6;
  color: var(--text-primary);
  background-color: var(--bg-color);
  transition: background-color var(--transition-normal), color var(--transition-normal);
  min-height: 100vh;
}

/* Typography */
h1, h2, h3, h4, h5, h6 {
  font-weight: 600;
  line-height: 1.3;
  color: var(--text-primary);
  margin-bottom: var(--spacing-md);
}

h1 { font-size: 2.25rem; }
h2 { font-size: 1.875rem; }
h3 { font-size: 1.5rem; }
h4 { font-size: 1.25rem; }
h5 { font-size: 1.125rem; }
h6 { font-size: 1rem; }

p {
  margin-bottom: var(--spacing-md);
  color: var(--text-secondary);
}

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

a:hover {
  color: var(--primary-dark);
  text-decoration: underline;
}

strong, b {
  font-weight: 600;
}

code {
  font-family: var(--font-mono);
  font-size: 0.875em;
  background: var(--bg-secondary);
  padding: 0.125rem 0.375rem;
  border-radius: var(--radius-sm);
  color: var(--primary-dark);
}

[data-theme="dark"] code {
  color: var(--primary-light);
}

pre {
  font-family: var(--font-mono);
  font-size: 0.875rem;
  background: var(--bg-secondary);
  padding: var(--spacing-md);
  border-radius: var(--radius-md);
  overflow-x: auto;
  margin-bottom: var(--spacing-md);
  border: 1px solid var(--border-color);
}

pre code {
  background: transparent;
  padding: 0;
  color: var(--text-primary);
}

/* Layout */
.app-container {
  display: flex;
  min-height: 100vh;
}

/* Sidebar */
.sidebar {
  position: fixed;
  top: 0;
  left: 0;
  width: var(--sidebar-width);
  height: 100vh;
  background: var(--bg-sidebar);
  color: var(--text-light);
  overflow-y: auto;
  z-index: 100;
  transition: transform var(--transition-normal);
}

.sidebar-header {
  padding: var(--spacing-lg);
  border-bottom: 1px solid rgba(255, 255, 255, 0.1);
  position: sticky;
  top: 0;
  background: var(--bg-sidebar);
  z-index: 10;
}

.sidebar-logo {
  display: flex;
  align-items: center;
  gap: var(--spacing-sm);
  color: #fff;
  font-size: 1.25rem;
  font-weight: 700;
  text-decoration: none;
}

.sidebar-logo:hover {
  text-decoration: none;
}

.sidebar-logo svg {
  width: 32px;
  height: 32px;
  fill: var(--primary-color);
}

.sidebar-subtitle {
  font-size: 0.75rem;
  color: var(--text-muted);
  margin-top: var(--spacing-xs);
  text-transform: uppercase;
  letter-spacing: 0.05em;
}

/* Navigation */
.nav-section {
  padding: var(--spacing-md) 0;
  border-bottom: 1px solid rgba(255, 255, 255, 0.05);
}

.nav-section:last-child {
  border-bottom: none;
}

.nav-section-title {
  padding: var(--spacing-sm) var(--spacing-lg);
  font-size: 0.7rem;
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 0.1em;
  color: var(--text-muted);
}

.nav-link {
  display: flex;
  align-items: center;
  padding: var(--spacing-sm) var(--spacing-lg);
  color: var(--text-light);
  font-size: 0.9rem;
  transition: all var(--transition-fast);
  border-left: 3px solid transparent;
  text-decoration: none;
}

.nav-link:hover {
  background: var(--bg-sidebar-hover);
  color: #fff;
  text-decoration: none;
}

.nav-link.active {
  background: rgba(37, 99, 235, 0.15);
  color: var(--primary-light);
  border-left-color: var(--primary-color);
}

.nav-link svg {
  width: 18px;
  height: 18px;
  margin-right: var(--spacing-sm);
  flex-shrink: 0;
}

/* Main Content */
.main-content {
  flex: 1;
  margin-left: var(--sidebar-width);
  min-height: 100vh;
}

/* Header */
.header {
  position: sticky;
  top: 0;
  height: var(--header-height);
  background: var(--bg-card);
  border-bottom: 1px solid var(--border-color);
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 0 var(--spacing-xl);
  z-index: 50;
  backdrop-filter: blur(8px);
  background: rgba(255, 255, 255, 0.9);
}

[data-theme="dark"] .header {
  background: rgba(15, 23, 42, 0.9);
}

.header-left {
  display: flex;
  align-items: center;
  gap: var(--spacing-md);
}

.menu-toggle {
  display: none;
  background: transparent;
  border: none;
  color: var(--text-primary);
  cursor: pointer;
  padding: var(--spacing-sm);
  border-radius: var(--radius-sm);
}

.menu-toggle:hover {
  background: var(--bg-secondary);
}

.menu-toggle svg {
  width: 24px;
  height: 24px;
}

.breadcrumb {
  display: flex;
  align-items: center;
  gap: var(--spacing-sm);
  font-size: 0.875rem;
  color: var(--text-muted);
}

.breadcrumb a {
  color: var(--text-muted);
}

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

.breadcrumb-separator {
  color: var(--text-muted);
}

.header-right {
  display: flex;
  align-items: center;
  gap: var(--spacing-md);
}

/* Search */
.search-container {
  position: relative;
}

.search-input {
  width: 280px;
  padding: var(--spacing-sm) var(--spacing-md);
  padding-left: 2.5rem;
  border: 1px solid var(--border-color);
  border-radius: var(--radius-full);
  background: var(--bg-secondary);
  color: var(--text-primary);
  font-size: 0.875rem;
  transition: all var(--transition-fast);
}

.search-input:focus {
  outline: none;
  border-color: var(--primary-color);
  box-shadow: 0 0 0 3px rgba(37, 99, 235, 0.1);
}

.search-input::placeholder {
  color: var(--text-muted);
}

.search-icon {
  position: absolute;
  left: var(--spacing-md);
  top: 50%;
  transform: translateY(-50%);
  color: var(--text-muted);
  width: 16px;
  height: 16px;
}

.search-results {
  position: absolute;
  top: calc(100% + var(--spacing-sm));
  left: 0;
  right: 0;
  background: var(--bg-card);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-md);
  box-shadow: var(--shadow-lg);
  max-height: 400px;
  overflow-y: auto;
  display: none;
  z-index: 100;
}

.search-results.active {
  display: block;
}

.search-result-item {
  display: block;
  padding: var(--spacing-sm) var(--spacing-md);
  color: var(--text-primary);
  border-bottom: 1px solid var(--border-color);
  transition: background var(--transition-fast);
}

.search-result-item:last-child {
  border-bottom: none;
}

.search-result-item:hover {
  background: var(--bg-secondary);
  text-decoration: none;
}

.search-result-item .result-title {
  font-weight: 500;
  display: block;
}

.search-result-item .result-path {
  font-size: 0.75rem;
  color: var(--text-muted);
}

/* Theme Toggle */
.theme-toggle {
  background: transparent;
  border: none;
  color: var(--text-primary);
  cursor: pointer;
  padding: var(--spacing-sm);
  border-radius: var(--radius-sm);
  display: flex;
  align-items: center;
  justify-content: center;
  transition: background var(--transition-fast);
}

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

.theme-toggle svg {
  width: 20px;
  height: 20px;
}

.theme-toggle .sun-icon { display: none; }
.theme-toggle .moon-icon { display: block; }

[data-theme="dark"] .theme-toggle .sun-icon { display: block; }
[data-theme="dark"] .theme-toggle .moon-icon { display: none; }

/* Content Area */
.content-wrapper {
  padding: var(--spacing-2xl);
  max-width: var(--content-max-width);
  margin: 0 auto;
}

.page-header {
  margin-bottom: var(--spacing-2xl);
  padding-bottom: var(--spacing-lg);
  border-bottom: 1px solid var(--border-color);
}

.page-title {
  font-size: 2rem;
  font-weight: 700;
  margin-bottom: var(--spacing-sm);
  color: var(--text-primary);
}

.page-description {
  font-size: 1.125rem;
  color: var(--text-secondary);
  max-width: 800px;
}

/* Cards */
.card-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(300px, 1fr));
  gap: var(--spacing-lg);
  margin-bottom: var(--spacing-2xl);
}

.card {
  background: var(--bg-card);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-lg);
  padding: var(--spacing-lg);
  transition: all var(--transition-normal);
}

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

.card-icon {
  width: 48px;
  height: 48px;
  background: linear-gradient(135deg, var(--primary-color), var(--secondary-color));
  border-radius: var(--radius-md);
  display: flex;
  align-items: center;
  justify-content: center;
  margin-bottom: var(--spacing-md);
}

.card-icon svg {
  width: 24px;
  height: 24px;
  color: #fff;
}

.card-title {
  font-size: 1.125rem;
  font-weight: 600;
  margin-bottom: var(--spacing-sm);
  color: var(--text-primary);
}

.card-description {
  font-size: 0.875rem;
  color: var(--text-secondary);
  margin-bottom: var(--spacing-md);
}

.card-link {
  display: inline-flex;
  align-items: center;
  font-size: 0.875rem;
  font-weight: 500;
  color: var(--primary-color);
}

.card-link svg {
  width: 16px;
  height: 16px;
  margin-left: var(--spacing-xs);
  transition: transform var(--transition-fast);
}

.card-link:hover svg {
  transform: translateX(4px);
}

/* Section */
.section {
  margin-bottom: var(--spacing-2xl);
}

.section-title {
  font-size: 1.5rem;
  font-weight: 600;
  margin-bottom: var(--spacing-lg);
  padding-bottom: var(--spacing-sm);
  border-bottom: 2px solid var(--primary-color);
  display: inline-block;
}

.section-intro {
  font-size: 1.125rem;
  color: var(--text-secondary);
  margin-bottom: var(--spacing-xl);
  max-width: 800px;
}

/* Content Blocks */
.content-block {
  background: var(--bg-card);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-lg);
  padding: var(--spacing-xl);
  margin-bottom: var(--spacing-lg);
}

.content-block h3 {
  font-size: 1.25rem;
  margin-bottom: var(--spacing-md);
}

.content-block h4 {
  font-size: 1.1rem;
  margin-bottom: var(--spacing-sm);
}

.content-block p {
  margin-bottom: var(--spacing-md);
}

.content-block ul, .content-block ol {
  margin-bottom: var(--spacing-md);
  padding-left: var(--spacing-xl);
}

.content-block li {
  margin-bottom: var(--spacing-sm);
  color: var(--text-secondary);
}

.content-block strong {
  color: var(--text-primary);
}

/* Tables */
.table-container {
  overflow-x: auto;
  margin-bottom: var(--spacing-lg);
}

table {
  width: 100%;
  border-collapse: collapse;
  font-size: 0.9rem;
}

th, td {
  padding: var(--spacing-sm) var(--spacing-md);
  text-align: left;
  border-bottom: 1px solid var(--border-color);
}

th {
  background: var(--bg-secondary);
  font-weight: 600;
  color: var(--text-primary);
}

tr:hover td {
  background: var(--bg-secondary);
}

td {
  color: var(--text-secondary);
}

/* Info Boxes */
.info-box {
  padding: var(--spacing-md);
  border-radius: var(--radius-md);
  margin-bottom: var(--spacing-md);
  border-left: 4px solid;
}

.info-box.info {
  background: rgba(59, 130, 246, 0.1);
  border-color: var(--info-color);
}

.info-box.warning {
  background: rgba(245, 158, 11, 0.1);
  border-color: var(--warning-color);
}

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

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

.info-box-title {
  font-weight: 600;
  margin-bottom: var(--spacing-xs);
  display: flex;
  align-items: center;
  gap: var(--spacing-sm);
}

.info-box-title svg {
  width: 18px;
  height: 18px;
}

.info-box p:last-child {
  margin-bottom: 0;
}

/* Code Blocks with Syntax Highlighting */
.code-block {
  position: relative;
  margin-bottom: var(--spacing-md);
}

.code-block pre {
  margin: 0;
}

.code-block .copy-btn {
  position: absolute;
  top: var(--spacing-sm);
  right: var(--spacing-sm);
  background: var(--bg-card);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-sm);
  padding: var(--spacing-xs) var(--spacing-sm);
  font-size: 0.75rem;
  cursor: pointer;
  color: var(--text-muted);
  transition: all var(--transition-fast);
}

.code-block .copy-btn:hover {
  background: var(--bg-secondary);
  color: var(--text-primary);
}

/* Syntax Highlighting */
.token.keyword { color: #c678dd; }
.token.string { color: #98c379; }
.token.number { color: #d19a66; }
.token.comment { color: #5c6370; font-style: italic; }
.token.function { color: #61afef; }
.token.operator { color: #56b6c2; }
.token.punctuation { color: #abb2bf; }
.token.class-name { color: #e5c07b; }
.token.property { color: #e06c75; }
.token.boolean { color: #d19a66; }

/* Back to Top */
.back-to-top {
  position: fixed;
  bottom: var(--spacing-xl);
  right: var(--spacing-xl);
  width: 48px;
  height: 48px;
  background: var(--primary-color);
  color: #fff;
  border: none;
  border-radius: var(--radius-full);
  cursor: pointer;
  display: flex;
  align-items: center;
  justify-content: center;
  box-shadow: var(--shadow-lg);
  opacity: 0;
  visibility: hidden;
  transition: all var(--transition-normal);
  z-index: 90;
}

.back-to-top.visible {
  opacity: 1;
  visibility: visible;
}

.back-to-top:hover {
  background: var(--primary-dark);
  transform: translateY(-4px);
}

.back-to-top svg {
  width: 24px;
  height: 24px;
}

/* Footer */
.footer {
  padding: var(--spacing-xl);
  border-top: 1px solid var(--border-color);
  text-align: center;
  color: var(--text-muted);
  font-size: 0.875rem;
}

/* TOC (Table of Contents) */
.toc {
  background: var(--bg-secondary);
  border-radius: var(--radius-md);
  padding: var(--spacing-lg);
  margin-bottom: var(--spacing-xl);
}

.toc-title {
  font-size: 0.875rem;
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 0.05em;
  color: var(--text-muted);
  margin-bottom: var(--spacing-md);
}

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

.toc-list li {
  margin-bottom: var(--spacing-xs);
}

.toc-list a {
  color: var(--text-secondary);
  font-size: 0.9rem;
  display: block;
  padding: var(--spacing-xs) 0;
  transition: color var(--transition-fast);
}

.toc-list a:hover {
  color: var(--primary-color);
  text-decoration: none;
}

/* Responsive */
@media (max-width: 1024px) {
  .sidebar {
    transform: translateX(-100%);
  }
  
  .sidebar.open {
    transform: translateX(0);
  }
  
  .main-content {
    margin-left: 0;
  }
  
  .menu-toggle {
    display: flex;
  }
  
  .search-input {
    width: 200px;
  }
}

@media (max-width: 768px) {
  .header {
    padding: 0 var(--spacing-md);
  }
  
  .search-container {
    display: none;
  }
  
  .content-wrapper {
    padding: var(--spacing-lg);
  }
  
  .page-title {
    font-size: 1.5rem;
  }
  
  .card-grid {
    grid-template-columns: 1fr;
  }
  
  .content-block {
    padding: var(--spacing-md);
  }
  
  .table-container {
    font-size: 0.8rem;
  }
  
  th, td {
    padding: var(--spacing-xs) var(--spacing-sm);
  }
}

@media (max-width: 480px) {
  .header-left {
    gap: var(--spacing-sm);
  }
  
  .breadcrumb {
    display: none;
  }
  
  .content-wrapper {
    padding: var(--spacing-md);
  }
  
  .page-title {
    font-size: 1.25rem;
  }
}

/* Print */
@media print {
  .sidebar,
  .header,
  .back-to-top,
  .search-container {
    display: none !important;
  }
  
  .main-content {
    margin-left: 0;
  }
  
  .content-wrapper {
    padding: 0;
  }
}

/* Animations */
@keyframes fadeIn {
  from { opacity: 0; }
  to { opacity: 1; }
}

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

.animate-fade-in {
  animation: fadeIn var(--transition-normal) ease-out;
}

.animate-slide-up {
  animation: slideUp var(--transition-slow) ease-out;
}

/* Stagger children */
.stagger-children > * {
  opacity: 0;
  animation: slideUp var(--transition-slow) ease-out forwards;
}

.stagger-children > *:nth-child(1) { animation-delay: 0ms; }
.stagger-children > *:nth-child(2) { animation-delay: 50ms; }
.stagger-children > *:nth-child(3) { animation-delay: 100ms; }
.stagger-children > *:nth-child(4) { animation-delay: 150ms; }
.stagger-children > *:nth-child(5) { animation-delay: 200ms; }
.stagger-children > *:nth-child(6) { animation-delay: 250ms; }
.stagger-children > *:nth-child(7) { animation-delay: 300ms; }
.stagger-children > *:nth-child(8) { animation-delay: 350ms; }

/* Highlight for search */
.highlight {
  background: rgba(245, 158, 11, 0.3);
  padding: 0 2px;
  border-radius: 2px;
}

/* Scrollbar */
::-webkit-scrollbar {
  width: 8px;
  height: 8px;
}

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

::-webkit-scrollbar-thumb {
  background: var(--text-muted);
  border-radius: var(--radius-full);
}

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

/* Selection */
::selection {
  background: rgba(37, 99, 235, 0.3);
}