/* ==========================================================================
   人工智能训练师（四级 / 中级工）实操题库全解系统 - 现代化全响应式样式表
   30 套全解精析 · 真实环境运行实测认证 · 纯净版
   特别针对长文本、复杂表格、多代码段进行人机工效学排版优化
   ========================================================================== */

:root {
  /* 基础主色调 */
  --primary: #2563eb;
  --primary-hover: #1d4ed8;
  --primary-light: #eff6ff;
  --primary-border: #bfdbfe;
  
  /* 模块专属主题色 */
  --mod1-color: #0284c7;
  --mod1-bg: #f0f9ff;
  --mod1-border: #bae6fd;
  
  --mod2-color: #d97706;
  --mod2-bg: #fffbeb;
  --mod2-border: #fde68a;
  
  --mod3-color: #7c3aed;
  --mod3-bg: #f5f3ff;
  --mod3-border: #ddd6fe;

  /* 状态辅助色 */
  --success: #10b981;
  --success-bg: #ecfdf5;
  --success-border: #a7f3d0;
  --danger: #ef4444;
  --danger-bg: #fef2f2;
  --danger-border: #fecaca;
  --warning: #f59e0b;
  --warning-bg: #fffbeb;
  --warning-border: #fde68a;

  /* 背景与中性文字 */
  --bg-main: #f8fafc;
  --bg-card: #ffffff;
  --bg-card-subtle: #f1f5f9;
  --bg-sidebar: #ffffff;
  --bg-code: #0f172a;
  --text-main: #0f172a;
  --text-secondary: #475569;
  --text-muted: #94a3b8;
  --border: #e2e8f0;
  --border-dark: #cbd5e1;

  /* 字体排印 */
  --font-sans: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", sans-serif;
  --font-mono: "Fira Code", "Cascadia Code", Consolas, Monaco, "Courier New", monospace;
  --base-font-size: 1rem;
  --base-line-height: 1.68;

  /* 阴影与圆角 */
  --shadow-sm: 0 1px 2px 0 rgb(0 0 0 / 0.05);
  --shadow: 0 4px 6px -1px rgb(0 0 0 / 0.07), 0 2px 4px -2px rgb(0 0 0 / 0.07);
  --shadow-lg: 0 10px 15px -3px rgb(0 0 0 / 0.08), 0 4px 6px -4px rgb(0 0 0 / 0.08);
  --radius: 12px;
  --radius-sm: 6px;
  --radius-lg: 16px;
}

[data-theme="dark"] {
  --primary: #3b82f6;
  --primary-hover: #60a5fa;
  --primary-light: #1e293b;
  --primary-border: #2563eb;

  --bg-main: #0b1120;
  --bg-card: #131d31;
  --bg-card-subtle: #1e293b;
  --bg-sidebar: #0f172a;
  --bg-code: #030712;
  --text-main: #f8fafc;
  --text-secondary: #94a3b8;
  --text-muted: #64748b;
  --border: #1e293b;
  --border-dark: #334155;

  --mod1-bg: #082f49;
  --mod1-border: #0284c7;
  --mod2-bg: #451a03;
  --mod2-border: #d97706;
  --mod3-bg: #2e1065;
  --mod3-border: #7c3aed;

  --success-bg: #064e3b;
  --success-border: #059669;
  --danger-bg: #450a0a;
  --danger-border: #dc2626;
}

/* 字体缩放预设 */
html {
  font-size: 15px;
  --base-font-size: 15px;
}
html.font-scale-sm {
  font-size: 13.5px;
  --base-font-size: 13.5px;
}
html.font-scale-md {
  font-size: 15px;
  --base-font-size: 15px;
}
html.font-scale-lg {
  font-size: 17.5px;
  --base-font-size: 17.5px;
}
html.font-scale-xl {
  font-size: 19.5px;
  --base-font-size: 19.5px;
}

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

html, body {
  font-family: var(--font-sans);
  background-color: var(--bg-main);
  color: var(--text-main);
  line-height: var(--base-line-height);
  font-size: 1rem;
  -webkit-font-smoothing: antialiased;
  min-height: 100vh;
}

/* 顶部导航栏 */
.navbar {
  position: sticky;
  top: 0;
  z-index: 50;
  background: rgba(255, 255, 255, 0.92);
  backdrop-filter: blur(14px);
  -webkit-backdrop-filter: blur(14px);
  border-bottom: 1px solid var(--border);
  min-height: 64px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 8px 24px;
  gap: 16px;
  transition: background-color 0.3s;
}

[data-theme="dark"] .navbar {
  background: rgba(15, 23, 42, 0.92);
}

.nav-brand {
  display: flex;
  align-items: center;
  gap: 12px;
  text-decoration: none;
  color: var(--text-main);
  flex-shrink: 0;
}

.brand-icon {
  width: 38px;
  height: 38px;
  border-radius: 10px;
  background: linear-gradient(135deg, var(--primary) 0%, #4f46e5 100%);
  display: flex;
  align-items: center;
  justify-content: center;
  color: white;
  font-size: 1.333rem;
  box-shadow: 0 4px 10px rgba(37, 99, 235, 0.25);
  flex-shrink: 0;
}

.brand-title {
  font-size: 1.067rem;
  font-weight: 700;
  letter-spacing: -0.01em;
  display: flex;
  align-items: center;
  gap: 8px;
}

.brand-badge {
  font-size: 0.733rem;
  font-weight: 600;
  padding: 2px 7px;
  border-radius: 12px;
  background: var(--primary-light);
  color: var(--primary);
  border: 1px solid var(--primary-border);
}

.brand-subtitle {
  font-size: 0.8rem;
  color: var(--text-secondary);
  font-weight: 400;
}

/* 导航栏动作按钮组 */
.nav-actions {
  display: flex;
  align-items: center;
  gap: 8px;
  flex-wrap: wrap;
}

.btn {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  padding: 6px 12px;
  font-size: 0.867rem;
  font-weight: 500;
  border-radius: var(--radius-sm);
  border: 1px solid var(--border);
  background: var(--bg-card);
  color: var(--text-main);
  cursor: pointer;
  transition: all 0.2s;
  white-space: nowrap;
}

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

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

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

/* 字体调节小工具 */
.font-controls {
  display: inline-flex;
  align-items: center;
  border: 1px solid var(--border);
  border-radius: var(--radius-sm);
  background: var(--bg-card);
  overflow: hidden;
}

.font-btn {
  border: none;
  background: transparent;
  padding: 5px 9px;
  font-size: 0.8rem;
  font-weight: 600;
  color: var(--text-secondary);
  cursor: pointer;
  transition: background 0.2s;
}

.font-btn:hover {
  background: var(--primary-light);
  color: var(--primary);
}

.font-btn.active {
  background: var(--primary);
  color: white;
}

/* 页面主体两栏布局 */
.layout-container {
  display: flex;
  min-height: calc(100vh - 64px);
}

/* 左侧侧边栏 */
.sidebar {
  width: 380px;
  flex-shrink: 0;
  background: var(--bg-sidebar);
  border-right: 1px solid var(--border);
  display: flex;
  flex-direction: column;
  height: calc(100vh - 64px);
  position: sticky;
  top: 64px;
}

.sidebar-header {
  padding: 16px;
  border-bottom: 1px solid var(--border);
  display: flex;
  flex-direction: column;
  gap: 12px;
  background: var(--bg-sidebar);
}

.search-box {
  position: relative;
  display: flex;
  align-items: center;
}

.search-icon {
  position: absolute;
  left: 12px;
  font-size: 0.933rem;
  color: var(--text-muted);
  pointer-events: none;
}

.search-input {
  width: 100%;
  padding: 8px 34px 8px 36px;
  font-size: 0.9rem;
  border: 1px solid var(--border);
  border-radius: var(--radius-sm);
  background: var(--bg-main);
  color: var(--text-main);
  outline: none;
  transition: border-color 0.2s, box-shadow 0.2s;
}

.search-input:focus {
  border-color: var(--primary);
  box-shadow: 0 0 0 3px rgba(37, 99, 235, 0.12);
  background: var(--bg-card);
}

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

.filter-chip {
  padding: 4px 10px;
  font-size: 0.8rem;
  font-weight: 500;
  border-radius: 20px;
  border: 1px solid var(--border);
  background: var(--bg-card);
  color: var(--text-secondary);
  cursor: pointer;
  transition: all 0.2s;
  white-space: nowrap;
}

.filter-chip:hover {
  border-color: var(--primary-border);
  color: var(--primary);
}

.filter-chip.active {
  background: var(--primary);
  border-color: var(--primary);
  color: white;
  font-weight: 600;
}

/* 侧边栏题目列表 */
.sidebar-list {
  flex: 1;
  overflow-y: auto;
  padding: 10px;
  display: flex;
  flex-direction: column;
  gap: 6px;
}

.question-item {
  padding: 12px 14px;
  border-radius: 10px;
  border: 1px solid transparent;
  background: var(--bg-card);
  cursor: pointer;
  transition: all 0.2s cubic-bezier(0.4, 0, 0.2, 1);
  display: flex;
  flex-direction: column;
  gap: 6px;
  position: relative;
}

.question-item:hover {
  background: var(--bg-card-subtle);
  border-color: var(--border-dark);
  transform: translateY(-1px);
}

.question-item.active {
  background: var(--primary-light);
  border-color: var(--primary-border);
  box-shadow: 0 2px 8px rgba(37, 99, 235, 0.1);
}

[data-theme="dark"] .question-item.active {
  background: rgba(37, 99, 235, 0.16);
  border-color: var(--primary);
}

.question-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 8px;
}

.question-badges {
  display: flex;
  align-items: center;
  gap: 6px;
  flex-wrap: wrap;
}

.q-code-badge {
  font-family: var(--font-mono);
  font-size: 0.733rem;
  font-weight: 700;
  padding: 2px 6px;
  border-radius: 4px;
  background: var(--bg-card-subtle);
  color: var(--text-secondary);
  border: 1px solid var(--border);
}

.q-points-badge {
  font-size: 0.733rem;
  font-weight: 700;
  padding: 2px 6px;
  border-radius: 4px;
  background: rgba(16, 185, 129, 0.12);
  color: var(--success);
}

.q-type-badge {
  font-size: 0.733rem;
  padding: 2px 6px;
  border-radius: 4px;
  background: rgba(14, 165, 233, 0.1);
  color: #0284c7;
}

.question-title {
  font-size: 0.9rem;
  font-weight: 600;
  line-height: 1.45;
  color: var(--text-main);
}

.question-subinfo {
  display: flex;
  align-items: center;
  justify-content: space-between;
  font-size: 0.767rem;
  color: var(--text-muted);
}

.verified-tag {
  display: inline-flex;
  align-items: center;
  gap: 3px;
  color: var(--success);
  font-weight: 600;
}

/* 右侧内容主展区 */
.content-area {
  flex: 1;
  padding: 28px 36px 64px 36px;
  overflow-y: auto;
  max-width: 1320px;
  margin: 0 auto;
  width: 100%;
}

/* 题目主头部区域 */
.detail-header-card {
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 24px 28px;
  margin-bottom: 24px;
  box-shadow: var(--shadow-sm);
  display: flex;
  flex-direction: column;
  gap: 16px;
  position: relative;
}

.detail-top-row {
  display: flex;
  align-items: flex-start;
  justify-content: space-between;
  gap: 16px;
}

.detail-title-group {
  display: flex;
  flex-direction: column;
  gap: 8px;
}

.detail-title {
  font-size: 1.467rem;
  font-weight: 700;
  line-height: 1.35;
  color: var(--text-main);
  letter-spacing: -0.015em;
}

.detail-meta-tags {
  display: flex;
  align-items: center;
  gap: 8px;
  flex-wrap: wrap;
}

.meta-tag {
  display: inline-flex;
  align-items: center;
  gap: 5px;
  font-size: 0.833rem;
  font-weight: 600;
  padding: 3px 10px;
  border-radius: 6px;
  background: var(--bg-card-subtle);
  color: var(--text-secondary);
  border: 1px solid var(--border);
}

.meta-tag-highlight {
  background: var(--primary-light);
  color: var(--primary);
  border-color: var(--primary-border);
}

.meta-tag-verified {
  background: var(--success-bg);
  color: var(--success);
  border-color: var(--success-border);
}

.detail-actions-bar {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 12px;
  padding-top: 14px;
  border-top: 1px solid var(--border);
  flex-wrap: wrap;
}

/* 核心内容卡片 (Card) */
.section-card {
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  margin-bottom: 20px;
  box-shadow: var(--shadow-sm);
  overflow: hidden;
  transition: border-color 0.2s, box-shadow 0.2s;
  scroll-margin-top: 80px;
}

.section-card:hover {
  border-color: var(--border-dark);
}

.section-header {
  padding: 16px 22px;
  background: var(--bg-card);
  border-bottom: 1px solid transparent;
  display: flex;
  align-items: center;
  justify-content: space-between;
  cursor: pointer;
  user-select: none;
  transition: background-color 0.2s;
}

.section-header:hover {
  background: var(--bg-card-subtle);
}

.section-card.open .section-header {
  border-bottom-color: var(--border);
}

.section-title {
  display: flex;
  align-items: center;
  gap: 10px;
  font-size: 1.067rem;
  font-weight: 700;
  color: var(--text-main);
}

.section-title-icon {
  font-size: 1.2rem;
}

.section-toggle-icon {
  font-size: 0.933rem;
  color: var(--text-muted);
  transition: transform 0.25s cubic-bezier(0.4, 0, 0.2, 1);
}

.section-card.open .section-toggle-icon {
  transform: rotate(180deg);
}

.section-content {
  display: none;
  padding: 22px;
  animation: fadeIn 0.2s ease-in-out;
}

.section-card.open .section-content {
  display: block;
}

@keyframes fadeIn {
  from { opacity: 0; transform: translateY(-4px); }
  to { opacity: 1; transform: translateY(0); }
}

/* 排版优化：长文本段落与背景说明 */
.scenario-desc-box {
  background: var(--bg-main);
  border: 1px solid var(--border);
  border-radius: 8px;
  padding: 16px 18px;
  margin-bottom: 18px;
  font-size: 0.967rem;
  line-height: 1.75;
  color: var(--text-main);
}

.scenario-title {
  font-size: 0.867rem;
  font-weight: 700;
  text-transform: uppercase;
  color: var(--text-secondary);
  letter-spacing: 0.05em;
  margin-bottom: 6px;
  display: flex;
  align-items: center;
  gap: 6px;
}

/* 考核任务清单 */
.req-list {
  display: flex;
  flex-direction: column;
  gap: 12px;
  margin-top: 14px;
}

.req-item {
  display: flex;
  align-items: flex-start;
  gap: 10px;
  padding: 12px 14px;
  border-radius: 8px;
  background: var(--bg-card-subtle);
  border: 1px solid var(--border);
  font-size: 0.967rem;
  line-height: 1.65;
}

.req-badge {
  font-size: 0.733rem;
  font-weight: 700;
  padding: 2px 7px;
  border-radius: 12px;
  background: var(--primary);
  color: white;
  flex-shrink: 0;
  margin-top: 2px;
}

/* 表格优雅排版 (Dense Tables) */
.table-responsive-wrapper {
  width: 100%;
  overflow-x: auto;
  margin: 16px 0;
  border: 1px solid var(--border);
  border-radius: 8px;
  box-shadow: 0 1px 3px rgba(0, 0, 0, 0.03);
}

.custom-data-table {
  width: 100%;
  border-collapse: collapse;
  font-size: 0.9rem;
  line-height: 1.6;
  text-align: left;
}

.custom-data-table th {
  background: var(--bg-card-subtle);
  color: var(--text-main);
  font-weight: 700;
  padding: 11px 14px;
  border-bottom: 1px solid var(--border);
  white-space: nowrap;
}

.custom-data-table td {
  padding: 10px 14px;
  border-bottom: 1px solid var(--border);
  color: var(--text-secondary);
  vertical-align: top;
}

.custom-data-table tr:last-child td {
  border-bottom: none;
}

.custom-data-table tbody tr:hover {
  background: rgba(37, 99, 235, 0.03);
}

[data-theme="dark"] .custom-data-table tbody tr:hover {
  background: rgba(255, 255, 255, 0.03);
}

.custom-data-table tbody tr:nth-child(even) {
  background: rgba(0, 0, 0, 0.015);
}

[data-theme="dark"] .custom-data-table tbody tr:nth-child(even) {
  background: rgba(255, 255, 255, 0.015);
}

/* 代码块展示盒子 (macOS Terminal Style) */
.code-container {
  background: var(--bg-code);
  border-radius: 10px;
  border: 1px solid #1e293b;
  margin: 16px 0;
  overflow: hidden;
  box-shadow: var(--shadow);
}

.code-container-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 9px 14px;
  background: #1e293b;
  border-bottom: 1px solid #334155;
}

.code-window-dots {
  display: flex;
  align-items: center;
  gap: 6px;
}

.dot {
  width: 11px;
  height: 11px;
  border-radius: 50%;
}
.dot-red { background: #ef4444; }
.dot-yellow { background: #f59e0b; }
.dot-green { background: #10b981; }

.code-lang-label {
  font-family: var(--font-mono);
  font-size: 0.767rem;
  color: #94a3b8;
  font-weight: 600;
  text-transform: uppercase;
}

.copy-code-btn {
  background: #334155;
  color: #f1f5f9;
  border: none;
  font-size: 0.8rem;
  padding: 4px 10px;
  border-radius: 5px;
  cursor: pointer;
  display: flex;
  align-items: center;
  gap: 5px;
  transition: all 0.2s;
}

.copy-code-btn:hover {
  background: var(--primary);
  color: white;
}

.copy-code-btn.copied {
  background: #059669 !important;
  color: #ffffff !important;
  box-shadow: 0 0 10px rgba(16, 185, 129, 0.4);
}

.code-content-wrapper {
  padding: 14px 16px;
  overflow-x: auto;
  font-family: var(--font-mono);
  font-size: 0.9rem;
  line-height: 1.65;
  color: #e2e8f0;
}

.code-line {
  display: flex;
  gap: 14px;
}

.code-line-num {
  color: #64748b;
  user-select: none;
  min-width: 24px;
  text-align: right;
  font-size: 0.8rem;
}

.code-comment { color: #6ee7b7; font-style: italic; }
.code-cmd { color: #38bdf8; font-weight: 600; }
.code-kw { color: #f472b6; font-weight: 600; }
.code-str { color: #fde047; }
.code-prompt { color: #94a3b8; user-select: none; }

/* 终端输出日志盒子 */
.terminal-output-box {
  background: #030712;
  border: 1px solid #1f2937;
  border-radius: 8px;
  padding: 12px 14px;
  margin: 12px 0;
  font-family: var(--font-mono);
  font-size: 0.867rem;
  line-height: 1.6;
  color: #4ade80;
  overflow-x: auto;
  white-space: pre-wrap;
  word-break: break-all;
}

.terminal-output-title {
  color: #9ca3af;
  font-size: 0.733rem;
  font-weight: 700;
  text-transform: uppercase;
  margin-bottom: 6px;
  display: flex;
  align-items: center;
  gap: 5px;
}

/* 官方实测图片展区 */
.screenshot-gallery {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(280px, 1fr));
  gap: 16px;
  margin: 18px 0;
}

.screenshot-card {
  border: 1px solid var(--border);
  border-radius: 8px;
  overflow: hidden;
  background: var(--bg-card);
  box-shadow: var(--shadow-sm);
  transition: transform 0.2s, box-shadow 0.2s;
  cursor: pointer;
}

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

.screenshot-img-wrapper {
  width: 100%;
  height: 180px;
  background: #000;
  display: flex;
  align-items: center;
  justify-content: center;
  overflow: hidden;
}

.screenshot-img {
  max-width: 100%;
  max-height: 100%;
  object-fit: contain;
  transition: transform 0.3s;
}

.screenshot-card:hover .screenshot-img {
  transform: scale(1.03);
}

.screenshot-info {
  padding: 10px 12px;
}

.screenshot-name {
  font-family: var(--font-mono);
  font-size: 0.8rem;
  font-weight: 700;
  color: var(--primary);
  margin-bottom: 3px;
}

.screenshot-desc {
  font-size: 0.8rem;
  color: var(--text-secondary);
  line-height: 1.4;
}

/* 实测验证报告卡片 */
.verification-card {
  border: 1px solid var(--success-border);
  background: var(--success-bg);
  border-radius: 8px;
  padding: 16px 18px;
  margin: 16px 0;
  display: flex;
  flex-direction: column;
  gap: 10px;
}

.verif-badge-row {
  display: flex;
  align-items: center;
  gap: 8px;
  font-size: 0.933rem;
  font-weight: 700;
  color: #065f46;
}

[data-theme="dark"] .verif-badge-row {
  color: #34d399;
}

.verif-text {
  font-size: 0.9rem;
  line-height: 1.65;
  color: #047857;
  white-space: pre-wrap;
}

[data-theme="dark"] .verif-text {
  color: #a7f3d0;
}

/* 官方评分与否定项卡片 */
.rubric-table {
  width: 100%;
  border-collapse: collapse;
  margin: 14px 0;
  font-size: 0.9rem;
}

.rubric-table th {
  background: var(--bg-card-subtle);
  padding: 10px 14px;
  font-weight: 700;
  border-bottom: 1px solid var(--border);
  color: var(--text-main);
  text-align: left;
}

.rubric-table td {
  padding: 10px 14px;
  border-bottom: 1px solid var(--border);
  color: var(--text-secondary);
}

.rubric-score {
  font-family: var(--font-mono);
  font-weight: 700;
  color: var(--primary);
}

.negation-box {
  background: var(--danger-bg);
  border: 1px solid var(--danger-border);
  border-radius: 8px;
  padding: 14px 16px;
  margin-top: 14px;
  color: #991b1b;
}

[data-theme="dark"] .negation-box {
  color: #fca5a5;
}

.negation-title {
  font-size: 0.9rem;
  font-weight: 700;
  display: flex;
  align-items: center;
  gap: 6px;
  margin-bottom: 6px;
}

.negation-content {
  font-size: 0.867rem;
  line-height: 1.6;
}

/* 考场秘籍避坑列表 */
.pitfall-list {
  display: flex;
  flex-direction: column;
  gap: 10px;
}

.pitfall-item {
  padding: 12px 14px;
  border-radius: 8px;
  background: var(--warning-bg);
  border: 1px solid var(--warning-border);
  font-size: 0.9rem;
  line-height: 1.65;
  color: #92400e;
}

[data-theme="dark"] .pitfall-item {
  color: #fcd34d;
}

/* 模态弹窗 (Modal) */
.modal-backdrop {
  display: none;
  position: fixed;
  inset: 0;
  background: rgba(0, 0, 0, 0.65);
  backdrop-filter: blur(4px);
  z-index: 100;
  align-items: center;
  justify-content: center;
  padding: 20px;
}

.modal-backdrop.open {
  display: flex;
}

.modal-container {
  background: var(--bg-card);
  border-radius: var(--radius-lg);
  width: 100%;
  max-width: 900px;
  max-height: 90vh;
  display: flex;
  flex-direction: column;
  box-shadow: 0 25px 50px -12px rgba(0, 0, 0, 0.35);
  border: 1px solid var(--border);
  overflow: hidden;
  animation: modalPop 0.25s cubic-bezier(0.16, 1, 0.3, 1);
}

@keyframes modalPop {
  from { opacity: 0; transform: scale(0.96); }
  to { opacity: 1; transform: scale(1); }
}

.modal-header {
  padding: 16px 22px;
  border-bottom: 1px solid var(--border);
  display: flex;
  align-items: center;
  justify-content: space-between;
}

.modal-title {
  font-size: 1.133rem;
  font-weight: 700;
  color: var(--text-main);
}

.modal-close-btn {
  background: none;
  border: none;
  font-size: 1.467rem;
  cursor: pointer;
  color: var(--text-muted);
  width: 32px;
  height: 32px;
  border-radius: 6px;
  display: flex;
  align-items: center;
  justify-content: center;
}

.modal-close-btn:hover {
  background: var(--bg-card-subtle);
  color: var(--text-main);
}

.modal-body {
  padding: 22px;
  overflow-y: auto;
  font-size: 0.933rem;
  line-height: 1.7;
}

/* 浮动 Toast 消息 */
.toast-msg {
  position: fixed;
  bottom: 24px;
  right: 24px;
  background: #1e293b;
  color: white;
  padding: 10px 18px;
  border-radius: 8px;
  font-size: 0.9rem;
  font-weight: 500;
  box-shadow: 0 10px 15px -3px rgba(0, 0, 0, 0.3);
  z-index: 1000;
  transform: translateY(100px);
  opacity: 0;
  transition: transform 0.3s cubic-bezier(0.16, 1, 0.3, 1), opacity 0.3s;
  pointer-events: none;
  display: flex;
  align-items: center;
  gap: 8px;
}

.toast-msg.show {
  transform: translateY(0);
  opacity: 1;
}

/* 响应式断点适配 */
@media (max-width: 1024px) {
  .sidebar {
    width: 320px;
  }
  .content-area {
    padding: 20px;
  }
}

/* ==========================================================================
   名师深度精讲专属高阶样式 (Teacher Masterclass Panel)
   ========================================================================== */
.lecture-card {
  border: 1px solid rgba(99, 102, 241, 0.4) !important;
  box-shadow: 0 4px 20px -2px rgba(99, 102, 241, 0.08) !important;
  position: relative;
  overflow: hidden;
}

[data-theme="dark"] .lecture-card {
  border-color: rgba(129, 140, 248, 0.4) !important;
  box-shadow: 0 4px 20px -2px rgba(99, 102, 241, 0.18) !important;
}

.lecture-card .section-header {
  background: linear-gradient(90deg, rgba(99, 102, 241, 0.08) 0%, rgba(168, 85, 247, 0.04) 100%);
  border-bottom: 1px solid rgba(99, 102, 241, 0.18);
}

.lecture-header-banner {
  background: linear-gradient(135deg, #4338ca 0%, #6366f1 50%, #7c3aed 100%);
  color: #ffffff;
  padding: 22px 24px;
  border-radius: 10px;
  margin-bottom: 22px;
  box-shadow: 0 10px 18px -3px rgba(79, 70, 229, 0.25);
}

.lecture-banner-badge {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  background: rgba(255, 255, 255, 0.22);
  backdrop-filter: blur(8px);
  padding: 4px 12px;
  border-radius: 9999px;
  font-size: 0.8rem;
  font-weight: 700;
  letter-spacing: 0.04em;
  margin-bottom: 12px;
}

.lecture-banner-title {
  font-size: 1.3rem;
  font-weight: 800;
  line-height: 1.4;
  margin-bottom: 10px;
  letter-spacing: -0.01em;
}

.lecture-banner-tagline {
  font-size: 0.967rem;
  line-height: 1.6;
  border-left: 3px solid rgba(255, 255, 255, 0.7);
  padding: 10px 14px;
  border-radius: 6px;
  background: rgba(0, 0, 0, 0.16);
  font-weight: 500;
}

.lecture-sections-list {
  display: flex;
  flex-direction: column;
  gap: 18px;
}

.lecture-section-box {
  background: var(--bg-main);
  border: 1px solid var(--border);
  border-radius: 10px;
  overflow: hidden;
  transition: transform 0.2s, box-shadow 0.2s, border-color 0.2s;
}

.lecture-section-box:hover {
  border-color: rgba(99, 102, 241, 0.5);
  box-shadow: var(--shadow);
}

.lecture-section-header {
  padding: 12px 18px;
  background: var(--bg-card);
  border-bottom: 1px solid var(--border);
  display: flex;
  align-items: center;
  gap: 10px;
  font-size: 1.033rem;
  font-weight: 700;
  color: var(--text-main);
}

.lecture-section-icon {
  font-size: 1.25rem;
  display: flex;
  align-items: center;
  justify-content: center;
}

.lecture-section-body {
  padding: 18px 22px;
  font-size: 0.95rem;
  line-height: 1.78;
  color: var(--text-main);
}

.lecture-section-body p {
  margin-bottom: 12px;
}

.lecture-section-body p:last-child {
  margin-bottom: 0;
}

.lecture-section-body ul, .lecture-section-body ol {
  padding-left: 22px;
  margin-bottom: 12px;
}

.lecture-section-body li {
  margin-bottom: 6px;
}

.lecture-section-body code {
  background: var(--bg-card-subtle);
  color: #b45309;
  padding: 2px 6px;
  border-radius: 4px;
  font-family: var(--font-mono);
  font-size: 0.9em;
  border: 1px solid var(--border);
}

[data-theme="dark"] .lecture-section-body code {
  color: #fcd34d;
  background: #1e293b;
}

.lecture-callout {
  padding: 12px 16px;
  border-radius: 8px;
  margin: 12px 0;
  border-left: 4px solid;
  line-height: 1.65;
}

.lecture-callout-warning {
  background: var(--warning-bg);
  border-color: var(--warning);
  color: #92400e;
}

[data-theme="dark"] .lecture-callout-warning {
  color: #fef3c7;
}

.lecture-callout-info {
  background: var(--primary-light);
  border-color: var(--primary);
  color: #1e40af;
}

[data-theme="dark"] .lecture-callout-info {
  color: #dbeafe;
}

.btn-lecture {
  background: linear-gradient(135deg, #4f46e5 0%, #7c3aed 100%) !important;
  color: #ffffff !important;
  border: none !important;
  font-weight: 700 !important;
  box-shadow: 0 2px 8px rgba(79, 70, 229, 0.35);
  transition: all 0.2s ease-in-out;
}

.btn-lecture:hover {
  background: linear-gradient(135deg, #4338ca 0%, #6d28d9 100%) !important;
  box-shadow: 0 4px 12px rgba(79, 70, 229, 0.45);
  transform: translateY(-1px);
}

.meta-tag-lecture {
  background: linear-gradient(135deg, rgba(99, 102, 241, 0.15) 0%, rgba(168, 85, 247, 0.15) 100%) !important;
  color: #4f46e5 !important;
  border-color: rgba(99, 102, 241, 0.35) !important;
  font-weight: 700;
  transition: all 0.2s ease-in-out;
}

[data-theme="dark"] .meta-tag-lecture {
  color: #a5b4fc !important;
  border-color: rgba(165, 180, 252, 0.35) !important;
}

.meta-tag-lecture:hover {
  background: linear-gradient(135deg, rgba(99, 102, 241, 0.25) 0%, rgba(168, 85, 247, 0.25) 100%) !important;
  transform: translateY(-1px);
}

.lecture-tag-badge {
  background: linear-gradient(135deg, #4f46e5 0%, #7c3aed 100%);
  color: #ffffff;
  font-size: 0.733rem;
  font-weight: 700;
  padding: 2px 8px;
  border-radius: 9999px;
  margin-left: 8px;
  vertical-align: middle;
  letter-spacing: 0.02em;
}

.lecture-h3 {
  font-size: 1.05rem;
  font-weight: 700;
  color: #4f46e5;
  margin: 18px 0 10px 0;
  display: flex;
  align-items: center;
  gap: 6px;
}

[data-theme="dark"] .lecture-h3 {
  color: #a5b4fc;
}

.lecture-h4 {
  font-size: 0.967rem;
  font-weight: 700;
  color: var(--text-main);
  margin: 14px 0 8px 0;
}

.lecture-locked-placeholder {
  transition: all 0.3s ease;
}

@media (max-width: 768px) {
  .navbar {
    flex-wrap: wrap;
    padding: 10px 16px;
    height: auto;
  }
  .layout-container {
    flex-direction: column;
  }
  .sidebar {
    width: 100%;
    height: auto;
    position: static;
    border-right: none;
    border-bottom: 1px solid var(--border);
  }
  .sidebar-list {
    max-height: 280px;
    overflow-y: auto;
    -webkit-overflow-scrolling: touch;
  }
  .filter-chips {
    flex-wrap: nowrap;
    overflow-x: auto;
    -webkit-overflow-scrolling: touch;
    padding-bottom: 6px;
  }
  .content-area {
    padding: 16px;
  }
}

/* 打印样式适配 */
@media print {
  .navbar, .sidebar, .detail-actions-bar, .copy-code-btn, .modal-backdrop {
    display: none !important;
  }
  .layout-container {
    display: block;
  }
  .content-area {
    padding: 0;
    max-width: 100%;
  }
  .section-card {
    border: 1px solid #ccc !important;
    break-inside: avoid;
    margin-bottom: 15px;
  }
  .section-content {
    display: block !important;
  }
  body {
    background: #fff !important;
    color: #000 !important;
  }
}