:root[data-theme="dark"] {
  --bg-main: #0d1117;
  --bg-surface: #161b22;
  --bg-elevated: #1f2631;
  --bg-code: #0b0e14;
  --border-color: #30363d;
  --text-primary: #e6edf3;
  --text-secondary: #9198a1;
  --text-muted: #6e7681;
  --accent: #10b981;
  --accent-hover: #059669;
  --accent-soft: rgba(16, 185, 129, 0.14);
  --blue: #3b82f6;
  --blue-soft: rgba(59, 130, 246, 0.14);
  --amber: #f59e0b;
  --amber-soft: rgba(245, 158, 11, 0.14);
  --danger: #ef4444;
  --shadow: 0 8px 24px rgba(0, 0, 0, 0.35);
}

:root[data-theme="light"] {
  --bg-main: #f6f8fa;
  --bg-surface: #ffffff;
  --bg-elevated: #eef2f6;
  --bg-code: #1e242c;
  --border-color: #d0d7de;
  --text-primary: #1f2328;
  --text-secondary: #57606a;
  --text-muted: #6e7781;
  --accent: #059669;
  --accent-hover: #047857;
  --accent-soft: rgba(5, 150, 105, 0.12);
  --blue: #2563eb;
  --blue-soft: rgba(37, 99, 235, 0.1);
  --amber: #d97706;
  --amber-soft: rgba(217, 119, 6, 0.12);
  --danger: #dc2626;
  --shadow: 0 6px 20px rgba(31, 35, 40, 0.08);
}

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

body {
  font-family: -apple-system, BlinkMacSystemFont, "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", "Noto Sans CJK SC", sans-serif;
  background-color: var(--bg-main);
  color: var(--text-primary);
  line-height: 1.7;
  overflow-x: hidden;
}

code, pre, textarea {
  font-family: "JetBrains Mono", "Fira Code", "SFMono-Regular", Consolas, "Liberation Mono", Menlo, monospace;
}

/* 顶部栏 */
.topbar {
  position: sticky;
  top: 0;
  z-index: 100;
  height: 62px;
  background: var(--bg-surface);
  border-bottom: 1px solid var(--border-color);
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 0 20px;
  gap: 14px;
}

.topbar-left {
  display: flex;
  align-items: center;
  gap: 10px;
}

.brand {
  display: flex;
  align-items: center;
  gap: 10px;
  cursor: pointer;
}

.brand-badge {
  background: linear-gradient(135deg, #10b981, #2563eb);
  color: #fff;
  font-weight: 800;
  font-size: 14px;
  padding: 5px 9px;
  border-radius: 8px;
  letter-spacing: 0.5px;
}

.brand-title {
  font-weight: 700;
  font-size: 16px;
  line-height: 1.2;
}

.brand-sub {
  font-size: 11px;
  color: var(--text-secondary);
}

.main-tabs {
  display: flex;
  gap: 6px;
  background: var(--bg-main);
  padding: 4px;
  border-radius: 10px;
  border: 1px solid var(--border-color);
}

.tab-btn {
  background: transparent;
  color: var(--text-secondary);
  border: none;
  padding: 7px 14px;
  border-radius: 7px;
  font-size: 13.5px;
  font-weight: 600;
  cursor: pointer;
  display: flex;
  align-items: center;
  gap: 6px;
  transition: all 0.15s ease;
}

.tab-btn:hover {
  color: var(--text-primary);
  background: var(--bg-elevated);
}

.tab-btn.active {
  background: var(--accent);
  color: #ffffff;
}

.pill-count, .pill-gpu {
  font-size: 11px;
  padding: 1px 6px;
  border-radius: 99px;
  background: rgba(255, 255, 255, 0.2);
}

.topbar-right {
  display: flex;
  align-items: center;
  gap: 10px;
}

.search-box input {
  width: 220px;
  padding: 7px 12px;
  border-radius: 8px;
  border: 1px solid var(--border-color);
  background: var(--bg-main);
  color: var(--text-primary);
  font-size: 13px;
}

.search-box input:focus {
  outline: none;
  border-color: var(--accent);
  width: 260px;
}

.lang-switch {
  display: flex;
  border: 1px solid var(--border-color);
  border-radius: 8px;
  overflow: hidden;
}

.lang-btn {
  background: var(--bg-main);
  color: var(--text-secondary);
  border: none;
  padding: 5px 10px;
  font-size: 12px;
  font-weight: 600;
  cursor: pointer;
}

.lang-btn.active {
  background: var(--blue);
  color: #fff;
}

.icon-btn {
  background: var(--bg-elevated);
  color: var(--text-primary);
  border: 1px solid var(--border-color);
  border-radius: 8px;
  width: 34px;
  height: 34px;
  cursor: pointer;
  font-size: 15px;
}

.mobile-menu-btn {
  display: none;
}

/* 视图容器 */
.view-panel {
  display: none;
}

.view-panel.active {
  display: block;
}

/* ==================== 视图 1：闯关路线图 ==================== */
#view-roadmap {
  max-width: 1320px;
  margin: 0 auto;
  padding: 28px 24px 60px;
}

.hero-banner {
  display: grid;
  grid-template-columns: 1.5fr 1fr;
  gap: 24px;
  background: var(--bg-surface);
  border: 1px solid var(--border-color);
  border-radius: 16px;
  padding: 28px;
  margin-bottom: 28px;
  box-shadow: var(--shadow);
}

.hero-eyebrow {
  display: inline-block;
  font-size: 12.5px;
  font-weight: 700;
  color: var(--accent);
  background: var(--accent-soft);
  padding: 4px 10px;
  border-radius: 99px;
  margin-bottom: 10px;
}

.hero-left h1 {
  font-size: 26px;
  line-height: 1.35;
  margin-bottom: 12px;
}

.hero-desc {
  color: var(--text-secondary);
  font-size: 14.5px;
  margin-bottom: 20px;
}

.hero-actions {
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
}

.primary-btn {
  background: var(--accent);
  color: #fff;
  border: none;
  padding: 9px 16px;
  border-radius: 9px;
  font-weight: 600;
  font-size: 13.5px;
  cursor: pointer;
  transition: background 0.15s;
}

.primary-btn:hover {
  background: var(--accent-hover);
}

.secondary-btn {
  background: var(--bg-elevated);
  color: var(--text-primary);
  border: 1px solid var(--border-color);
  padding: 9px 15px;
  border-radius: 9px;
  font-weight: 600;
  font-size: 13.5px;
  cursor: pointer;
}

.secondary-btn:hover {
  border-color: var(--accent);
}

.hero-stats-card {
  background: var(--bg-main);
  border: 1px solid var(--border-color);
  border-radius: 12px;
  padding: 20px;
  display: flex;
  flex-direction: column;
  justify-content: center;
  gap: 12px;
}

.progress-ring-row {
  display: flex;
  justify-content: space-around;
  text-align: center;
}

.stat-big {
  font-size: 26px;
  font-weight: 800;
  color: var(--accent);
}

.stat-label {
  font-size: 12px;
  color: var(--text-secondary);
}

.progress-bar-track {
  height: 8px;
  background: var(--bg-elevated);
  border-radius: 99px;
  overflow: hidden;
}

.progress-bar-fill {
  height: 100%;
  background: linear-gradient(90deg, #10b981, #3b82f6);
  transition: width 0.3s ease;
}

.roadmap-mode-selector {
  display: flex;
  gap: 10px;
  flex-wrap: wrap;
  margin-top: 4px;
}

.roadmap-radio {
  flex: 1;
  display: flex;
  align-items: center;
  gap: 6px;
  background: var(--bg-surface);
  border: 1px solid var(--border-color);
  padding: 7px 10px;
  border-radius: 8px;
  font-size: 12.5px;
  font-weight: 600;
  cursor: pointer;
}

.roadmap-mode-desc {
  font-size: 12px;
  color: var(--text-secondary);
  line-height: 1.5;
}

.roadmap-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(360px, 1fr));
  gap: 18px;
}

.chapter-card {
  background: var(--bg-surface);
  border: 1px solid var(--border-color);
  border-radius: 14px;
  padding: 20px;
  display: flex;
  flex-direction: column;
  justify-content: space-between;
  gap: 14px;
  transition: transform 0.15s, border-color 0.15s;
  cursor: pointer;
  position: relative;
}

.chapter-card:hover {
  transform: translateY(-2px);
  border-color: var(--accent);
}

.chapter-card.completed {
  border-color: rgba(16, 185, 129, 0.6);
}

.card-top-row {
  display: flex;
  justify-content: space-between;
  align-items: center;
  gap: 8px;
}

.step-order-pill {
  font-size: 11.5px;
  font-weight: 700;
  padding: 2px 9px;
  border-radius: 99px;
  background: var(--blue-soft);
  color: var(--blue);
}

.badge-pill {
  font-size: 11.5px;
  font-weight: 600;
  padding: 2px 9px;
  border-radius: 99px;
  background: var(--accent-soft);
  color: var(--accent);
}

.chapter-card h3 {
  font-size: 17px;
  line-height: 1.35;
  margin-top: 6px;
}

.chapter-card-en {
  font-size: 12px;
  color: var(--text-muted);
}

.chapter-card-meta {
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
  font-size: 12px;
  color: var(--text-secondary);
}

.chapter-card-footer {
  display: flex;
  justify-content: space-between;
  align-items: center;
  padding-top: 10px;
  border-top: 1px solid var(--border-color);
}

/* ==================== 视图 2：章节精读 ==================== */
.reader-layout {
  display: grid;
  grid-template-columns: 290px 1fr;
  height: calc(100vh - 62px);
}

.reader-sidebar {
  background: var(--bg-surface);
  border-right: 1px solid var(--border-color);
  padding: 16px;
  display: flex;
  flex-direction: column;
  gap: 16px;
  overflow-y: auto;
}

.sidebar-label {
  font-size: 11.5px;
  font-weight: 700;
  text-transform: uppercase;
  color: var(--text-muted);
  margin-bottom: 8px;
  letter-spacing: 0.5px;
}

.chapter-select {
  width: 100%;
  padding: 9px 10px;
  border-radius: 8px;
  background: var(--bg-main);
  color: var(--text-primary);
  border: 1px solid var(--border-color);
  font-size: 13.5px;
  font-weight: 600;
}

.sidebar-quick-links, .chapter-toc-list {
  display: flex;
  flex-direction: column;
  gap: 4px;
}

.toc-link {
  display: block;
  padding: 6px 10px;
  border-radius: 6px;
  color: var(--text-secondary);
  text-decoration: none;
  font-size: 13px;
  line-height: 1.4;
  transition: background 0.12s;
}

.toc-link:hover {
  background: var(--bg-elevated);
  color: var(--text-primary);
}

.toc-link.special {
  font-weight: 600;
  color: var(--text-primary);
}

.toc-link.level-2 {
  padding-left: 22px;
  font-size: 12.5px;
}

.reader-content {
  overflow-y: auto;
  padding: 32px 24px 90px;
  scroll-behavior: smooth;
}

.reader-inner {
  max-width: 900px;
  margin: 0 auto;
}

.chapter-hero-box {
  background: var(--bg-surface);
  border: 1px solid var(--border-color);
  border-radius: 16px;
  padding: 26px;
  margin-bottom: 24px;
}

.chapter-hero-top {
  display: flex;
  justify-content: space-between;
  align-items: center;
  margin-bottom: 10px;
}

.chapter-hero-box h1 {
  font-size: 28px;
  line-height: 1.3;
}

.chapter-hero-en {
  font-size: 14px;
  color: var(--text-secondary);
  margin-top: 4px;
}

/* 助学四件套卡片 */
.study-card {
  background: var(--bg-surface);
  border: 1px solid var(--border-color);
  border-radius: 14px;
  padding: 22px 24px;
  margin-bottom: 24px;
}

.study-card.intuition-card {
  border-left: 4px solid var(--accent);
}

.study-card.api-card {
  border-left: 4px solid var(--blue);
}

.study-card.quiz-card {
  border-left: 4px solid var(--amber);
}

.study-card-title {
  font-size: 18px;
  font-weight: 700;
  margin-bottom: 14px;
  display: flex;
  align-items: center;
  justify-content: space-between;
}

.intuition-grid {
  display: grid;
  gap: 12px;
}

.intuition-item {
  background: var(--bg-main);
  padding: 12px 16px;
  border-radius: 10px;
  border: 1px solid var(--border-color);
}

.intuition-item-label {
  font-size: 12px;
  font-weight: 700;
  color: var(--accent);
  margin-bottom: 4px;
}

.takeaways-list {
  padding-left: 20px;
  margin-top: 6px;
}

.api-item {
  background: var(--bg-main);
  border: 1px solid var(--border-color);
  border-radius: 10px;
  padding: 14px 16px;
  margin-bottom: 12px;
}

.api-sig {
  font-family: "JetBrains Mono", monospace;
  font-size: 13.5px;
  color: #38bdf8;
  background: var(--bg-code);
  padding: 8px 12px;
  border-radius: 7px;
  margin-bottom: 8px;
  overflow-x: auto;
  white-space: pre-wrap;
}

.api-gotcha {
  margin-top: 8px;
  font-size: 13px;
  background: var(--amber-soft);
  color: var(--text-primary);
  padding: 8px 12px;
  border-radius: 7px;
  border-left: 3px solid var(--amber);
}

/* 随堂微测验 */
.quiz-item {
  background: var(--bg-main);
  border: 1px solid var(--border-color);
  border-radius: 10px;
  padding: 16px;
  margin-bottom: 14px;
}

.quiz-q {
  font-weight: 600;
  margin-bottom: 10px;
}

.quiz-options {
  display: flex;
  flex-direction: column;
  gap: 7px;
}

.quiz-opt-btn {
  text-align: left;
  padding: 9px 13px;
  border-radius: 8px;
  border: 1px solid var(--border-color);
  background: var(--bg-surface);
  color: var(--text-primary);
  cursor: pointer;
  font-size: 13.5px;
}

.quiz-opt-btn:hover {
  border-color: var(--blue);
}

.quiz-opt-btn.correct {
  background: rgba(16, 185, 129, 0.2);
  border-color: var(--accent);
}

.quiz-opt-btn.wrong {
  background: rgba(239, 68, 68, 0.2);
  border-color: var(--danger);
}

.quiz-exp {
  margin-top: 10px;
  padding: 10px 12px;
  border-radius: 8px;
  background: var(--accent-soft);
  font-size: 13px;
}

/* 原书正文渲染样式 */
.book-body-header {
  display: flex;
  justify-content: space-between;
  align-items: center;
  margin: 36px 0 18px;
  padding-bottom: 12px;
  border-bottom: 2px solid var(--border-color);
}

.book-heading-1 {
  font-size: 23px;
  margin: 34px 0 14px;
  padding-bottom: 8px;
  border-bottom: 1px solid var(--border-color);
  color: var(--text-primary);
}

.book-heading-2 {
  font-size: 19px;
  margin: 26px 0 12px;
  color: var(--accent);
}

.book-heading-3 {
  font-size: 16.5px;
  margin: 20px 0 10px;
}

.heading-en-sub {
  display: block;
  font-size: 13px;
  font-weight: 400;
  color: var(--text-muted);
  margin-top: 2px;
}

.book-para {
  margin-bottom: 15px;
  font-size: 15.5px;
}

.step-badge-pill {
  display: inline-block;
  background: var(--blue);
  color: #fff;
  font-weight: 700;
  font-size: 12px;
  padding: 1px 8px;
  border-radius: 6px;
  margin-right: 8px;
}

.bilingual-en {
  margin-top: 6px;
  padding: 8px 12px;
  border-left: 2px solid var(--border-color);
  color: var(--text-secondary);
  font-size: 13.5px;
  background: rgba(128, 128, 128, 0.05);
  border-radius: 0 6px 6px 0;
}

.book-list {
  margin: 0 0 16px 24px;
}

.book-list li {
  margin-bottom: 8px;
  font-size: 15px;
}

.book-code-block {
  background: var(--bg-code);
  border: 1px solid var(--border-color);
  border-radius: 10px;
  margin: 16px 0 20px;
  overflow: hidden;
}

.code-block-bar {
  display: flex;
  justify-content: space-between;
  align-items: center;
  padding: 7px 14px;
  background: rgba(255, 255, 255, 0.04);
  border-bottom: 1px solid var(--border-color);
  font-size: 12px;
  color: var(--text-secondary);
}

.code-block-actions {
  display: flex;
  gap: 8px;
}

.xs-btn {
  background: var(--bg-elevated);
  color: var(--text-primary);
  border: 1px solid var(--border-color);
  padding: 3px 9px;
  border-radius: 6px;
  font-size: 11.5px;
  font-weight: 600;
  cursor: pointer;
}

.xs-btn:hover {
  border-color: var(--accent);
}

.xs-btn.accent {
  background: var(--accent);
  color: #fff;
  border-color: var(--accent);
}

.xs-btn.danger {
  background: rgba(239, 68, 68, 0.2);
  color: #f87171;
  border-color: var(--danger);
}

.book-code-block pre {
  padding: 14px 16px;
  overflow-x: auto;
  font-size: 13.5px;
  line-height: 1.55;
  color: #e6edf3;
}

.inline-code {
  background: var(--bg-elevated);
  color: #38bdf8;
  padding: 2px 6px;
  border-radius: 5px;
  font-size: 0.9em;
}

.book-figure {
  background: var(--bg-surface);
  border: 1px solid var(--border-color);
  border-radius: 12px;
  padding: 16px;
  margin: 20px 0;
  text-align: center;
}

.book-figure img {
  max-width: 100%;
  height: auto;
  border-radius: 8px;
  cursor: zoom-in;
}

.book-figcaption {
  margin-top: 10px;
  font-size: 13.5px;
  color: var(--text-secondary);
}

/* 第 9 章矩阵公式图片透明底保护（保证暗色主题下黑字公式清晰可见） */
.equation-img-box {
  text-align: center;
  margin: 16px 0;
}

.equation-img-box img,
.inline-formula-img {
  background: #f8fafc;
  padding: 4px 8px;
  border-radius: 6px;
  border: 1px solid #cbd5e1;
}

.book-callout {
  border-radius: 10px;
  padding: 14px 18px;
  margin: 18px 0;
  background: var(--blue-soft);
  border-left: 4px solid var(--blue);
}

.book-callout.tip {
  background: var(--accent-soft);
  border-left-color: var(--accent);
}

.book-table-wrap {
  overflow-x: auto;
  margin: 18px 0;
}

.book-table {
  width: 100%;
  border-collapse: collapse;
  font-size: 14px;
}

.book-table th, .book-table td {
  border: 1px solid var(--border-color);
  padding: 9px 12px;
  text-align: left;
}

.book-table th {
  background: var(--bg-elevated);
}

/* ==================== 视图 3：视觉调参实验室 ==================== */
.labs-layout {
  display: grid;
  grid-template-columns: 280px 1fr;
  min-height: calc(100vh - 62px);
}

.labs-sidebar {
  background: var(--bg-surface);
  border-right: 1px solid var(--border-color);
  padding: 14px;
  display: flex;
  flex-direction: column;
  gap: 8px;
  overflow-y: auto;
}

.lab-nav-item {
  padding: 10px 12px;
  border-radius: 10px;
  border: 1px solid var(--border-color);
  background: var(--bg-main);
  cursor: pointer;
  transition: all 0.15s;
}

.lab-nav-item:hover {
  border-color: var(--accent);
}

.lab-nav-item.active {
  background: var(--accent-soft);
  border-color: var(--accent);
}

.lab-nav-ch {
  font-size: 11px;
  font-weight: 700;
  color: var(--accent);
}

.lab-nav-title {
  font-size: 13.5px;
  font-weight: 600;
  margin-top: 2px;
}

.labs-workspace {
  padding: 24px;
  max-width: 1280px;
}

.lab-header-bar {
  display: flex;
  justify-content: space-between;
  align-items: flex-start;
  gap: 16px;
  margin-bottom: 20px;
}

.lab-subtitle {
  color: var(--text-secondary);
  font-size: 14px;
  margin-top: 4px;
}

.lab-header-actions {
  display: flex;
  gap: 10px;
}

.lab-main-grid {
  display: grid;
  grid-template-columns: 340px 1fr;
  gap: 20px;
}

.lab-controls-card, .lab-visual-card {
  background: var(--bg-surface);
  border: 1px solid var(--border-color);
  border-radius: 14px;
  padding: 20px;
}

.control-group {
  margin-bottom: 16px;
}

.control-label {
  display: flex;
  justify-content: space-between;
  font-size: 13px;
  font-weight: 600;
  margin-bottom: 6px;
}

.control-val-badge {
  color: var(--accent);
  font-family: monospace;
}

.sample-pills {
  display: flex;
  flex-wrap: wrap;
  gap: 6px;
  margin-top: 8px;
}

.sample-pill {
  padding: 4px 10px;
  border-radius: 7px;
  font-size: 12px;
  border: 1px solid var(--border-color);
  background: var(--bg-main);
  color: var(--text-secondary);
  cursor: pointer;
}

.sample-pill.active {
  background: var(--blue);
  color: #fff;
  border-color: var(--blue);
}

.upload-row {
  margin-top: 10px;
  display: flex;
  align-items: center;
  gap: 8px;
}

.upload-btn {
  display: inline-block;
  padding: 6px 12px;
  border-radius: 7px;
  background: var(--bg-elevated);
  border: 1px dashed var(--border-color);
  font-size: 12.5px;
  cursor: pointer;
}

.dynamic-controls input[type="range"] {
  width: 100%;
  accent-color: var(--accent);
}

.dynamic-controls select {
  width: 100%;
  padding: 8px 10px;
  border-radius: 8px;
  background: var(--bg-main);
  color: var(--text-primary);
  border: 1px solid var(--border-color);
  font-size: 13px;
}

.divider {
  border: none;
  border-top: 1px solid var(--border-color);
  margin: 14px 0;
}

.lab-metrics-strip {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 8px;
  margin-top: 14px;
}

.metric-chip {
  background: var(--bg-main);
  border: 1px solid var(--border-color);
  padding: 8px 10px;
  border-radius: 8px;
}

.metric-chip-label {
  font-size: 11px;
  color: var(--text-muted);
}

.metric-chip-val {
  font-size: 13.5px;
  font-weight: 700;
  color: var(--accent);
}

.image-compare-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 14px;
  margin-bottom: 14px;
}

.img-box {
  background: var(--bg-main);
  border: 1px solid var(--border-color);
  border-radius: 10px;
  overflow: hidden;
}

.img-box.highlight {
  border-color: var(--accent);
}

.img-box-header {
  padding: 8px 12px;
  font-size: 12.5px;
  font-weight: 600;
  background: var(--bg-elevated);
  display: flex;
  justify-content: space-between;
}

.live-indicator {
  color: var(--accent);
  font-size: 12px;
}

.img-frame {
  min-height: 240px;
  max-height: 360px;
  display: flex;
  align-items: center;
  justify-content: center;
  padding: 10px;
}

.img-frame img {
  max-width: 100%;
  max-height: 330px;
  object-fit: contain;
  border-radius: 6px;
  cursor: zoom-in;
}

.lab-explanation-box {
  background: var(--accent-soft);
  border-left: 4px solid var(--accent);
  padding: 11px 14px;
  border-radius: 8px;
  font-size: 13.5px;
  margin-bottom: 14px;
}

.code-card {
  background: var(--bg-code);
  border: 1px solid var(--border-color);
  border-radius: 10px;
  overflow: hidden;
}

.code-card-header {
  display: flex;
  justify-content: space-between;
  align-items: center;
  padding: 8px 14px;
  background: rgba(255, 255, 255, 0.04);
  border-bottom: 1px solid var(--border-color);
  font-size: 12.5px;
}

.code-pre {
  padding: 12px 14px;
  font-size: 13px;
  color: #e6edf3;
  overflow-x: auto;
}

/* ==================== 视图 4：在线代码沙盒 ==================== */
.sandbox-layout {
  max-width: 1400px;
  margin: 0 auto;
  padding: 18px 24px 40px;
}

.sandbox-toolbar {
  display: flex;
  justify-content: space-between;
  align-items: center;
  flex-wrap: wrap;
  gap: 12px;
  background: var(--bg-surface);
  border: 1px solid var(--border-color);
  padding: 12px 16px;
  border-radius: 12px;
  margin-bottom: 12px;
}

.sandbox-toolbar-left, .sandbox-toolbar-right {
  display: flex;
  align-items: center;
  gap: 10px;
  flex-wrap: wrap;
}

.template-select {
  padding: 7px 12px;
  border-radius: 8px;
  background: var(--bg-main);
  color: var(--text-primary);
  border: 1px solid var(--border-color);
  font-size: 13px;
  min-width: 280px;
}

.engine-selector {
  display: flex;
  gap: 6px;
  background: var(--bg-main);
  padding: 4px 8px;
  border-radius: 8px;
  border: 1px solid var(--border-color);
  font-size: 12.5px;
}

.engine-option {
  display: flex;
  align-items: center;
  gap: 5px;
  cursor: pointer;
  padding: 3px 6px;
}

.colab-control-bar {
  display: flex;
  justify-content: space-between;
  align-items: center;
  background: var(--blue-soft);
  border: 1px solid var(--blue);
  padding: 10px 16px;
  border-radius: 10px;
  margin-bottom: 12px;
  font-size: 13px;
}

.gpu-chip {
  background: var(--blue);
  color: #fff;
  font-weight: 700;
  font-size: 11.5px;
  padding: 2px 8px;
  border-radius: 6px;
  margin-right: 8px;
}

.sandbox-samples-bar {
  display: flex;
  align-items: center;
  flex-wrap: wrap;
  gap: 8px;
  background: var(--bg-surface);
  border: 1px solid var(--border-color);
  padding: 8px 14px;
  border-radius: 10px;
  margin-bottom: 14px;
  font-size: 12.5px;
}

.samples-chips {
  display: flex;
  flex-wrap: wrap;
  gap: 6px;
}

.sample-chip {
  background: var(--bg-elevated);
  border: 1px solid var(--border-color);
  padding: 2px 8px;
  border-radius: 6px;
  font-family: monospace;
  font-size: 12px;
  cursor: pointer;
}

.sample-chip:hover {
  border-color: var(--accent);
  color: var(--accent);
}

.sandbox-main-split {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 16px;
  min-height: 560px;
}

.sandbox-editor-pane, .sandbox-output-pane {
  background: var(--bg-surface);
  border: 1px solid var(--border-color);
  border-radius: 12px;
  overflow: hidden;
  display: flex;
  flex-direction: column;
}

.pane-header {
  padding: 10px 14px;
  background: var(--bg-elevated);
  border-bottom: 1px solid var(--border-color);
  font-size: 12.5px;
  font-weight: 600;
  display: flex;
  justify-content: space-between;
  align-items: center;
}

.hint-text {
  font-size: 11.5px;
  color: var(--text-secondary);
  font-weight: 400;
}

#sandboxCodeEditor {
  flex: 1;
  width: 100%;
  min-height: 480px;
  background: var(--bg-code);
  color: #e6edf3;
  border: none;
  padding: 16px;
  font-size: 13.5px;
  line-height: 1.6;
  resize: vertical;
}

#sandboxCodeEditor:focus {
  outline: none;
}

.sandbox-images-gallery {
  padding: 14px;
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(220px, 1fr));
  gap: 12px;
  min-height: 280px;
  max-height: 380px;
  overflow-y: auto;
}

.sandbox-img-card {
  background: var(--bg-main);
  border: 1px solid var(--border-color);
  border-radius: 8px;
  padding: 8px;
  text-align: center;
}

.sandbox-img-card img {
  max-width: 100%;
  max-height: 220px;
  border-radius: 6px;
  cursor: zoom-in;
}

.sandbox-img-meta {
  font-size: 11.5px;
  color: var(--text-secondary);
  margin-top: 6px;
  font-family: monospace;
}

.sandbox-console {
  background: var(--bg-code);
  color: #a7f3d0;
  padding: 12px 14px;
  font-size: 12.5px;
  min-height: 140px;
  max-height: 220px;
  overflow-y: auto;
  white-space: pre-wrap;
}

/* 搜索弹窗与 Lightbox */
.hidden {
  display: none !important;
}

.search-modal {
  position: fixed;
  inset: 0;
  background: rgba(0, 0, 0, 0.65);
  z-index: 200;
  display: flex;
  justify-content: center;
  padding-top: 70px;
}

.search-modal-content {
  background: var(--bg-surface);
  border: 1px solid var(--border-color);
  border-radius: 14px;
  width: 90%;
  max-width: 720px;
  max-height: 75vh;
  display: flex;
  flex-direction: column;
  box-shadow: var(--shadow);
}

.search-modal-header {
  padding: 14px 18px;
  border-bottom: 1px solid var(--border-color);
  display: flex;
  justify-content: space-between;
  font-weight: 700;
}

.search-results-list {
  padding: 12px;
  overflow-y: auto;
  display: flex;
  flex-direction: column;
  gap: 8px;
}

.search-hit-item {
  padding: 10px 14px;
  border-radius: 8px;
  background: var(--bg-main);
  border: 1px solid var(--border-color);
  cursor: pointer;
}

.search-hit-item:hover {
  border-color: var(--accent);
}

.lightbox {
  position: fixed;
  inset: 0;
  background: rgba(0, 0, 0, 0.88);
  z-index: 300;
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  padding: 24px;
  cursor: zoom-out;
}

.lightbox img {
  max-width: 92vw;
  max-height: 82vh;
  border-radius: 8px;
  background: #fff;
}

.lightbox-caption {
  color: #e6edf3;
  margin-top: 12px;
  font-size: 14px;
  max-width: 800px;
  text-align: center;
}

/* ==================== Colab G4 实跑实验成果库 ==================== */
.g4-showcase-container {
  max-width: 1320px;
  margin: 0 auto;
  padding: 28px 24px 70px;
}

.g4-banner-card {
  display: grid;
  grid-template-columns: 1.5fr 1fr;
  gap: 24px;
  background: var(--bg-surface);
  border: 1px solid var(--blue);
  border-radius: 16px;
  padding: 26px;
  margin-bottom: 28px;
  box-shadow: var(--shadow);
}

.g4-banner-left h2 {
  font-size: 24px;
  line-height: 1.35;
  margin-bottom: 10px;
}

.g4-hw-specs {
  background: var(--bg-main);
  border: 1px solid var(--border-color);
  border-radius: 12px;
  padding: 16px 18px;
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 10px;
  align-content: center;
}

.g4-hw-item {
  background: var(--bg-surface);
  border: 1px solid var(--border-color);
  border-radius: 8px;
  padding: 8px 12px;
}

.g4-hw-label {
  font-size: 11px;
  color: var(--text-muted);
}

.g4-hw-val {
  font-size: 13px;
  font-weight: 700;
  color: #38bdf8;
  margin-top: 2px;
}

.g4-experiments-list {
  display: flex;
  flex-direction: column;
  gap: 24px;
}

.g4-exp-card {
  background: var(--bg-surface);
  border: 1px solid var(--border-color);
  border-left: 4px solid #38bdf8;
  border-radius: 14px;
  padding: 22px 24px;
  box-shadow: var(--shadow);
}

.study-card.g4-chapter-card {
  border-left: 4px solid #38bdf8;
}

.g4-exp-header {
  display: flex;
  justify-content: space-between;
  align-items: flex-start;
  gap: 12px;
  flex-wrap: wrap;
  margin-bottom: 8px;
}

.g4-exp-title {
  font-size: 18px;
  font-weight: 700;
  color: var(--text-primary);
}

.g4-exp-summary {
  color: var(--text-secondary);
  font-size: 14px;
  margin-bottom: 14px;
}

.g4-exp-img-wrap {
  background: #0f172a;
  border: 1px solid var(--border-color);
  border-radius: 10px;
  padding: 10px;
  text-align: center;
  margin-bottom: 14px;
}

.g4-exp-img-wrap img {
  max-width: 100%;
  height: auto;
  border-radius: 6px;
  cursor: zoom-in;
}

.g4-exp-metrics {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(180px, 1fr));
  gap: 10px;
  margin-bottom: 12px;
}

.g4-exp-log {
  background: var(--bg-code);
  color: #a7f3d0;
  border: 1px solid var(--border-color);
  border-radius: 8px;
  padding: 10px 14px;
  font-size: 12.5px;
  line-height: 1.55;
  overflow-x: auto;
  white-space: pre-wrap;
}

@media (max-width: 980px) {
  .hero-banner, .g4-banner-card, .lab-main-grid, .sandbox-main-split, .image-compare-grid {
    grid-template-columns: 1fr;
  }
  .reader-layout, .labs-layout {
    grid-template-columns: 1fr;
  }
  .reader-sidebar {
    display: none;
  }
  .reader-sidebar.mobile-open {
    display: flex;
    position: fixed;
    top: 62px;
    left: 0;
    bottom: 0;
    width: 280px;
    z-index: 150;
  }
  .mobile-menu-btn {
    display: inline-block;
  }
}