/* ABOUTME: Main stylesheet for 物理实验平台 */

/* Reset and base styles */
* {
  margin: 0;
  padding: 0;
  box-sizing: border-box;
}

:root {
  --primary: #1a73e8;
  --primary-dark: #1557b0;
  --teal: #0d9488;
  --teal-dark: #0a7a70;
  --bg-white: #ffffff;
  --bg-light: #f8fafc;
  --bg-gray: #f1f5f9;
  --text-dark: #1e293b;
  --text-medium: #475569;
  --text-light: #64748b;
  --border: #e2e8f0;
  --shadow-sm: 0 1px 2px rgba(0,0,0,0.05);
  --shadow-md: 0 4px 6px -1px rgba(0,0,0,0.07), 0 2px 4px -2px rgba(0,0,0,0.05);
  --shadow-lg: 0 10px 15px -3px rgba(0,0,0,0.08), 0 4px 6px -4px rgba(0,0,0,0.05);
  --shadow-hover: 0 20px 25px -5px rgba(0,0,0,0.1), 0 8px 10px -6px rgba(0,0,0,0.05);
  --amber: #f59e0b;
  --amber-bg: #fffbeb;
  --amber-border: #fde68a;
  --green: #10b981;
  --radius: 12px;
  --radius-sm: 8px;
  --transition: all 0.2s ease;
}

body {
  font-family: -apple-system, BlinkMacSystemFont, 'PingFang SC', 'Microsoft YaHei', 'Segoe UI', sans-serif;
  background: var(--bg-light);
  color: var(--text-dark);
  line-height: 1.75;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}

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

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

/* ===== Navigation ===== */
.navbar {
  position: sticky;
  top: 0;
  z-index: 100;
  background: var(--bg-white);
  border-bottom: 1px solid var(--border);
  box-shadow: var(--shadow-sm);
}

.navbar-inner {
  max-width: 1200px;
  margin: 0 auto;
  padding: 0 24px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: 64px;
}

.navbar-logo {
  display: flex;
  align-items: center;
  gap: 10px;
  font-size: 1.25rem;
  font-weight: 700;
  color: var(--text-dark);
}

.navbar-logo svg {
  width: 32px;
  height: 32px;
}

.navbar-links {
  display: flex;
  align-items: center;
  gap: 8px;
  list-style: none;
}

.navbar-links a {
  display: inline-block;
  padding: 6px 16px;
  border-radius: 8px;
  font-size: 0.9375rem;
  color: var(--text-medium);
  font-weight: 500;
  transition: var(--transition);
}

.navbar-links a:hover {
  background: var(--bg-gray);
  color: var(--primary);
}

.mobile-menu-btn {
  display: none;
  background: none;
  border: none;
  cursor: pointer;
  padding: 8px;
  color: var(--text-medium);
}

/* ===== Hero Section ===== */
.hero {
  background: linear-gradient(135deg, #1a73e8 0%, #0d9488 100%);
  color: #fff;
  padding: 80px 24px;
  text-align: center;
  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(255,255,255,0.08) 0%, transparent 50%),
    radial-gradient(circle at 80% 20%, rgba(255,255,255,0.06) 0%, transparent 50%);
  pointer-events: none;
}

.hero-decoration {
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  bottom: 0;
  pointer-events: none;
  opacity: 0.12;
}

.hero-content {
  position: relative;
  z-index: 1;
  max-width: 800px;
  margin: 0 auto;
}

.hero h1 {
  font-size: 3rem;
  font-weight: 800;
  margin-bottom: 16px;
  letter-spacing: -0.02em;
  line-height: 1.2;
}

.hero .subtitle {
  font-size: 1.1875rem;
  opacity: 0.9;
  line-height: 1.6;
  font-weight: 400;
}

.hero .badge {
  display: inline-block;
  margin-top: 24px;
  padding: 8px 20px;
  background: rgba(255,255,255,0.15);
  border: 1px solid rgba(255,255,255,0.25);
  border-radius: 999px;
  font-size: 0.875rem;
  backdrop-filter: blur(4px);
}

/* ===== Section ===== */
.section {
  max-width: 1200px;
  margin: 0 auto;
  padding: 60px 24px;
}

.section-title {
  font-size: 1.75rem;
  font-weight: 700;
  color: var(--text-dark);
  margin-bottom: 8px;
}

.section-desc {
  color: var(--text-light);
  font-size: 1rem;
  margin-bottom: 36px;
}

/* ===== Experiment Cards ===== */
.card-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 24px;
}

.card {
  background: var(--bg-white);
  border-radius: var(--radius);
  border: 1px solid var(--border);
  padding: 28px;
  transition: var(--transition);
  display: flex;
  flex-direction: column;
  position: relative;
  overflow: hidden;
}

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

.card-tag {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  padding: 4px 12px;
  background: linear-gradient(135deg, var(--primary), var(--teal));
  color: #fff;
  border-radius: 999px;
  font-size: 0.8125rem;
  font-weight: 600;
  margin-bottom: 16px;
  width: fit-content;
}

.card-tag-optional,
.card-tag-required,
.card-tag-sim {
  display: inline-block;
  padding: 1px 8px;
  border-radius: 999px;
  font-size: 0.6875rem;
  font-weight: 500;
  margin-left: 2px;
}
.card-tag-required {
  background: rgba(255,255,255,0.3);
}
.card-tag-optional {
  background: rgba(255,255,255,0.3);
}
.card-tag-sim {
  background: rgba(255,255,255,0.3);
}

.card-chapter {
  font-size: 0.8125rem;
  color: var(--teal);
  font-weight: 600;
  margin-bottom: 8px;
}

.card h3 {
  font-size: 1.1875rem;
  font-weight: 700;
  color: var(--text-dark);
  margin-bottom: 10px;
  line-height: 1.4;
}

.card p {
  font-size: 0.9375rem;
  color: var(--text-light);
  line-height: 1.6;
  flex: 1;
}

.card-link {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  margin-top: 20px;
  font-size: 0.9375rem;
  font-weight: 600;
  color: var(--primary);
  transition: var(--transition);
}

.card-link:hover {
  gap: 10px;
  color: var(--primary-dark);
}

.card-link svg {
  width: 16px;
  height: 16px;
  transition: var(--transition);
}

/* ===== Footer ===== */
.footer {
  background: var(--text-dark);
  color: rgba(255,255,255,0.6);
  text-align: center;
  padding: 32px 24px;
  font-size: 0.875rem;
}

/* ===== Breadcrumb ===== */
.breadcrumb {
  max-width: 900px;
  margin: 0 auto;
  padding: 20px 24px 0;
  font-size: 0.875rem;
  color: var(--text-light);
}

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

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

.breadcrumb span {
  margin: 0 8px;
  color: var(--border);
}

/* ===== Experiment Detail ===== */
.exp-detail {
  max-width: 900px;
  margin: 0 auto;
  padding: 32px 24px 80px;
}

.exp-header {
  margin-bottom: 40px;
}

.exp-header .exp-tag {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  padding: 4px 14px;
  background: linear-gradient(135deg, var(--primary), var(--teal));
  color: #fff;
  border-radius: 999px;
  font-size: 0.8125rem;
  font-weight: 600;
  margin-bottom: 12px;
}

.exp-tag-optional {
  display: inline-block;
  padding: 1px 8px;
  background: rgba(255,255,255,0.3);
  border-radius: 999px;
  font-size: 0.6875rem;
  font-weight: 500;
}

.exp-header h1 {
  font-size: 2rem;
  font-weight: 800;
  color: var(--text-dark);
  margin-bottom: 8px;
  line-height: 1.3;
}

.exp-header .exp-chapter {
  font-size: 0.9375rem;
  color: var(--teal);
  font-weight: 600;
}

.exp-section {
  margin-bottom: 36px;
}

.exp-section h2 {
  font-size: 1.25rem;
  font-weight: 700;
  color: var(--text-dark);
  margin-bottom: 16px;
  padding-bottom: 8px;
  border-bottom: 2px solid var(--bg-gray);
  display: flex;
  align-items: center;
  gap: 10px;
}

.exp-section h2 .icon {
  width: 24px;
  height: 24px;
  color: var(--primary);
  flex-shrink: 0;
}

.exp-section ul,
.exp-section ol {
  padding-left: 24px;
  margin-bottom: 8px;
}

.exp-section li {
  margin-bottom: 8px;
  line-height: 1.75;
  color: var(--text-medium);
}

.exp-section ol li::marker {
  color: var(--primary);
  font-weight: 600;
}

/* ===== Data Table ===== */
.data-table-wrapper {
  overflow-x: auto;
  margin-top: 12px;
  border-radius: var(--radius-sm);
  border: 1px solid var(--border);
}

.data-table {
  width: 100%;
  border-collapse: collapse;
  font-size: 0.9375rem;
}

.data-table th {
  background: var(--bg-gray);
  padding: 12px 16px;
  text-align: center;
  font-weight: 600;
  color: var(--text-dark);
  border-bottom: 2px solid var(--border);
  white-space: nowrap;
}

.data-table td {
  padding: 10px 16px;
  text-align: center;
  border-bottom: 1px solid var(--border);
  color: var(--text-medium);
}

.data-table tbody tr:nth-child(even) {
  background: var(--bg-light);
}

.data-table tbody tr:hover {
  background: #eef2ff;
}

/* ===== Notice Box ===== */
.notice-box {
  background: var(--amber-bg);
  border: 1px solid var(--amber-border);
  border-left: 4px solid var(--amber);
  border-radius: var(--radius-sm);
  padding: 20px 24px;
  margin-top: 12px;
}

.notice-box ul {
  padding-left: 20px;
  margin: 0;
}

.notice-box li {
  color: #92400e;
  margin-bottom: 6px;
  font-size: 0.9375rem;
}

/* ===== Collapsible ===== */
.collapsible {
  border: 1px solid var(--border);
  border-radius: var(--radius-sm);
  overflow: hidden;
  margin-top: 12px;
}

.collapsible-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 14px 20px;
  background: var(--bg-white);
  cursor: pointer;
  font-weight: 600;
  color: var(--text-dark);
  transition: var(--transition);
  border: none;
  width: 100%;
  text-align: left;
  font-size: 0.9375rem;
}

.collapsible-header:hover {
  background: var(--bg-light);
}

.collapsible-header svg {
  width: 20px;
  height: 20px;
  color: var(--text-light);
  transition: transform 0.2s ease;
  flex-shrink: 0;
}

.collapsible-header.active svg {
  transform: rotate(180deg);
}

.collapsible-body {
  max-height: 0;
  overflow: hidden;
  transition: max-height 0.3s ease;
}

.collapsible-body-inner {
  padding: 0 20px 20px;
}

/* ===== Back Button ===== */
.back-btn {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 10px 24px;
  background: var(--bg-white);
  border: 1px solid var(--border);
  border-radius: var(--radius-sm);
  color: var(--text-medium);
  font-weight: 600;
  font-size: 0.9375rem;
  cursor: pointer;
  transition: var(--transition);
  margin-top: 24px;
}

.back-btn:hover {
  border-color: var(--primary);
  color: var(--primary);
  box-shadow: var(--shadow-sm);
}

.back-btn svg {
  width: 18px;
  height: 18px;
}

/* ===== Sub-section in steps ===== */
.sub-section {
  margin-top: 20px;
  margin-bottom: 16px;
}

.sub-section h3 {
  font-size: 1rem;
  font-weight: 700;
  color: var(--teal);
  margin-bottom: 10px;
}

/* ===== Interactive Simulation ===== */
.sim-section {
  margin-top: 40px;
  padding-top: 32px;
  border-top: 2px solid var(--border);
}
.sim-section-title {
  font-size: 1.5rem;
  font-weight: 700;
  color: var(--primary);
  margin-bottom: 8px;
  display: flex;
  align-items: center;
  gap: 10px;
}
.sim-section-title::before {
  content: '';
  display: inline-block;
  width: 4px;
  height: 28px;
  background: linear-gradient(135deg, var(--primary), var(--teal));
  border-radius: 2px;
}
.sim-desc {
  color: var(--text-secondary);
  font-size: 0.95rem;
  margin-bottom: 20px;
}
.sim-layout,
.sim-container {
  display: grid;
  grid-template-columns: 1fr 320px;
  gap: 24px;
  margin-bottom: 24px;
}
@media (max-width: 900px) {
  .sim-layout,
  .sim-container { grid-template-columns: 1fr; }
}
/* sim-container 的直接子元素 sim-data（如 exp7）强制放右列 */
.sim-container > .sim-data {
  grid-column: 2;
}
@media (max-width: 900px) {
  .sim-container > .sim-data { grid-column: 1; }
}
.sim-canvas-wrap {
  background: #0f172a;
  border-radius: 12px;
  overflow: hidden;
  position: relative;
}
.sim-canvas-wrap canvas {
  display: block;
  width: 100%;
  height: auto;
}
.sim-controls {
  background: var(--bg-light);
  border-radius: 12px;
  padding: 20px;
  display: flex;
  flex-direction: column;
  gap: 14px;
}
.sim-control-group label {
  display: block;
  font-size: 0.85rem;
  font-weight: 600;
  color: var(--text-primary);
  margin-bottom: 4px;
}
.sim-control-group .sim-val {
  float: right;
  font-weight: 400;
  color: var(--primary);
  font-family: 'Courier New', monospace;
}
.sim-control-group input[type="range"] {
  width: 100%;
  height: 6px;
  -webkit-appearance: none;
  appearance: none;
  background: #e2e8f0;
  border-radius: 3px;
  outline: none;
  cursor: pointer;
}
.sim-control-group input[type="range"]::-webkit-slider-thumb {
  -webkit-appearance: none;
  width: 18px;
  height: 18px;
  border-radius: 50%;
  background: var(--primary);
  cursor: pointer;
  box-shadow: 0 1px 4px rgba(0,0,0,.2);
}
.sim-control-group select {
  width: 100%;
  padding: 6px 10px;
  border: 1px solid var(--border);
  border-radius: 6px;
  font-size: 0.9rem;
  background: #fff;
  cursor: pointer;
}
.sim-btns {
  display: flex;
  gap: 8px;
  margin-top: 4px;
}
.sim-btn {
  flex: 1;
  padding: 8px 12px;
  border: none;
  border-radius: 8px;
  font-size: 0.9rem;
  font-weight: 600;
  cursor: pointer;
  transition: background .2s;
}
.sim-btn-start {
  background: var(--primary);
  color: #fff;
}
.sim-btn-start:hover { background: #1557b0; }
.sim-btn-pause {
  background: var(--teal);
  color: #fff;
}
.sim-btn-pause:hover { background: #0a7a6f; }
.sim-btn-reset {
  background: #e2e8f0;
  color: var(--text-primary);
}
.sim-btn-reset:hover { background: #cbd5e1; }
.sim-data {
  background: #0f172a;
  border-radius: 8px;
  padding: 12px 16px;
  font-family: 'Courier New', monospace;
  font-size: 0.82rem;
  color: #94a3b8;
  line-height: 1.7;
}
.sim-data span { color: #38bdf8; font-weight: 600; }
.sim-data .val-warn { color: #fbbf24; }
.sim-data .val-ok { color: #34d399; }

/* ===== Content Tabs (below simulation) ===== */
.content-tabs {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
  margin-top: 16px;
  margin-bottom: 16px;
}
.content-tab-btn {
  padding: 8px 18px;
  border: 1.5px solid var(--border);
  border-radius: 8px;
  background: var(--bg-white);
  font-size: 0.9rem;
  font-weight: 500;
  color: var(--text-medium);
  cursor: pointer;
  transition: var(--transition);
  display: flex;
  align-items: center;
  gap: 6px;
}
.content-tab-btn:hover {
  border-color: var(--primary);
  color: var(--primary);
  background: #eff6ff;
}
.content-tab-btn.active {
  border-color: var(--primary);
  background: var(--primary);
  color: #fff;
}
.content-tab-btn svg {
  width: 16px;
  height: 16px;
}
.content-panel {
  max-height: 0;
  overflow: hidden;
  transition: max-height 0.35s ease;
}
.content-panel.open {
  max-height: 2000px;
}
.content-panel-inner {
  background: var(--bg-white);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 24px;
  margin-bottom: 16px;
}
.content-panel-inner h3 {
  font-size: 1.1rem;
  font-weight: 600;
  color: var(--text-dark);
  margin-bottom: 12px;
  display: flex;
  align-items: center;
  gap: 8px;
}
.content-panel-inner h3 svg {
  width: 20px;
  height: 20px;
  color: var(--primary);
}
.content-panel-inner ol,
.content-panel-inner ul {
  padding-left: 20px;
}
.content-panel-inner li {
  margin-bottom: 6px;
  line-height: 1.8;
}
.content-panel-inner .notice-box {
  background: var(--amber-bg);
  border: 1px solid var(--amber-border);
  border-radius: var(--radius-sm);
  padding: 16px;
}

/* ===== Responsive ===== */
@media (max-width: 1024px) {
  .card-grid {
    grid-template-columns: repeat(2, 1fr);
  }
}

@media (max-width: 768px) {
  .navbar-links {
    display: none;
    position: absolute;
    top: 64px;
    left: 0;
    right: 0;
    background: var(--bg-white);
    flex-direction: column;
    padding: 16px;
    border-bottom: 1px solid var(--border);
    box-shadow: var(--shadow-md);
  }

  .navbar-links.open {
    display: flex;
  }

  .mobile-menu-btn {
    display: block;
  }

  .hero {
    padding: 48px 20px;
  }

  .hero h1 {
    font-size: 2rem;
  }

  .hero .subtitle {
    font-size: 1rem;
  }

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

  .section {
    padding: 40px 16px;
  }

  .exp-detail {
    padding: 24px 16px 60px;
  }

  .exp-header h1 {
    font-size: 1.5rem;
  }
}

/* ===== Print Styles ===== */
@media print {
  .navbar, .footer, .back-btn, .breadcrumb {
    display: none !important;
  }

  .hero {
    display: none !important;
  }

  body {
    background: #fff;
    color: #000;
  }

  .exp-detail {
    max-width: 100%;
    padding: 0;
  }

  .data-table {
    font-size: 0.8125rem;
  }

  .notice-box {
    border: 1px solid #ccc;
    background: #fefefe;
  }
}