/* ============================================================
   吃瓜网新闻事实核查与谣言粉碎平台 - 主样式表
   吃瓜大赛 | lcm1eo.cn
   版本: 1.0.0 | Mobile-First响应式设计
   ============================================================ */

/* ============================================================
   1. CSS 变量定义（Design Tokens）
   ============================================================ */
:root {
  /* 主色调：深沉的蓝灰色，传递权威、稳重、专业的品牌形象 */
  --primary: #37474F;
  /* 辅助色：稍浅的蓝灰色，用于次级导航、边框或次要文本 */
  --secondary: #455A64;
  /* 背景色：极浅的灰白色，提供舒适的阅读环境 */
  --bg: #FAFAFA;
  /* 卡片背景色：纯白色 */
  --card-bg: #FFFFFF;
  /* 强调色/真实标签色：沉稳的绿色 */
  --accent: #4CAF50;
  /* 危险色/虚假标签色：醒目的红色 */
  --danger: #F44336;
  /* 警告色/存疑标签色：明亮的橙黄色 */
  --warning: #FF9800;
  /* 信息色：蓝色，用于"断章取义"等标签 */
  --info: #2196F3;
  /* 半真半假：蓝紫色 */
  --mixed: #9C27B0;
  /* 主文本色 */
  --text: #1A1A1A;
  /* 次文本色 */
  --text-muted: #757575;
  /* 边框与分割线颜色 */
  --border: #E0E0E0;
  /* 阴影 */
  --shadow-sm: 0 1px 3px rgba(0,0,0,0.08);
  --shadow-md: 0 4px 12px rgba(0,0,0,0.12);
  --shadow-lg: 0 8px 24px rgba(0,0,0,0.16);
  /* 圆角 */
  --radius-sm: 4px;
  --radius-md: 8px;
  --radius-lg: 12px;
  /* 间距系统 */
  --space-xs: 4px;
  --space-sm: 8px;
  --space-md: 16px;
  --space-lg: 24px;
  --space-xl: 32px;
  --space-2xl: 48px;
  --space-3xl: 64px;
  /* 字体 */
  --font-sans: "PingFang SC", "Microsoft YaHei", "Noto Sans SC", -apple-system, BlinkMacSystemFont, sans-serif;
  --font-mono: "Roboto Mono", "Courier New", Consolas, monospace;
  /* 过渡动效 */
  --transition: 0.25s ease;
  --transition-slow: 0.4s ease;
  /* 最大宽度 */
  --max-width: 1280px;
  --content-width: 900px;
}

/* ============================================================
   2. CSS Reset & 基础样式
   ============================================================ */
*, *::before, *::after {
  box-sizing: border-box;
  margin: 0;
  padding: 0;
}

html {
  font-size: 16px;
  scroll-behavior: smooth;
  -webkit-text-size-adjust: 100%;
}

body {
  font-family: var(--font-sans);
  font-size: 1rem;
  line-height: 1.7;
  color: var(--text);
  background-color: var(--bg);
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}

img, video {
  max-width: 100%;
  height: auto;
  display: block;
}

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

a:hover {
  color: var(--accent);
}

ul, ol {
  list-style: none;
}

button {
  cursor: pointer;
  border: none;
  background: none;
  font-family: inherit;
}

input, textarea, select {
  font-family: inherit;
  font-size: inherit;
}

/* ============================================================
   3. 工具类
   ============================================================ */
.container {
  width: 100%;
  max-width: var(--max-width);
  margin: 0 auto;
  padding: 0 var(--space-md);
}

.sr-only {
  position: absolute;
  width: 1px;
  height: 1px;
  padding: 0;
  margin: -1px;
  overflow: hidden;
  clip: rect(0,0,0,0);
  white-space: nowrap;
  border: 0;
}

.text-muted { color: var(--text-muted); }
.text-center { text-align: center; }
.text-right { text-align: right; }
.font-bold { font-weight: 700; }
.font-mono { font-family: var(--font-mono); }

/* ============================================================
   4. 全局头部 (Header)
   ============================================================ */
.site-header {
  position: sticky;
  top: 0;
  z-index: 1000;
  background: var(--primary);
  box-shadow: var(--shadow-md);
}

.header-top {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: var(--space-md) 0;
  gap: var(--space-md);
}

.site-logo {
  display: flex;
  align-items: center;
  gap: var(--space-sm);
  text-decoration: none;
  flex-shrink: 0;
}

.site-logo img {
  width: 40px;
  height: 40px;
  border-radius: var(--radius-sm);
  object-fit: contain;
}

.site-logo-text {
  font-size: 1.25rem;
  font-weight: 700;
  color: #fff;
  letter-spacing: -0.02em;
}

.site-logo-text span {
  color: #4CAF50;
}

/* 搜索框 */
.header-search {
  flex: 1;
  max-width: 520px;
  position: relative;
}

.header-search-form {
  display: flex;
  align-items: center;
  background: rgba(255,255,255,0.12);
  border: 1px solid rgba(255,255,255,0.25);
  border-radius: 50px;
  overflow: hidden;
  transition: background var(--transition), border-color var(--transition);
}

.header-search-form:focus-within {
  background: rgba(255,255,255,0.2);
  border-color: rgba(255,255,255,0.5);
}

.header-search-input {
  flex: 1;
  padding: 10px var(--space-md);
  background: transparent;
  border: none;
  color: #fff;
  font-size: 0.9rem;
  outline: none;
}

.header-search-input::placeholder {
  color: rgba(255,255,255,0.6);
}

.header-search-btn {
  padding: 10px var(--space-md);
  color: rgba(255,255,255,0.8);
  transition: color var(--transition);
  font-size: 1rem;
}

.header-search-btn:hover {
  color: #fff;
}

/* 头部操作区 */
.header-actions {
  display: flex;
  align-items: center;
  gap: var(--space-sm);
  flex-shrink: 0;
}

.btn-submit-tip {
  display: inline-flex;
  align-items: center;
  gap: var(--space-xs);
  padding: 8px var(--space-md);
  background: var(--danger);
  color: #fff;
  border-radius: 50px;
  font-size: 0.85rem;
  font-weight: 600;
  transition: background var(--transition), transform var(--transition);
  white-space: nowrap;
}

.btn-submit-tip:hover {
  background: #d32f2f;
  color: #fff;
  transform: translateY(-1px);
}

/* 汉堡菜单 */
.menu-toggle {
  display: none;
  flex-direction: column;
  gap: 5px;
  padding: 8px;
  color: #fff;
}

.menu-toggle span {
  display: block;
  width: 22px;
  height: 2px;
  background: currentColor;
  border-radius: 2px;
  transition: transform var(--transition), opacity var(--transition);
}

/* 主导航 */
.main-nav {
  border-top: 1px solid rgba(255,255,255,0.1);
}

.nav-list {
  display: flex;
  align-items: center;
  gap: 0;
}

.nav-item {
  position: relative;
}

.nav-link {
  display: block;
  padding: 12px var(--space-md);
  color: rgba(255,255,255,0.85);
  font-size: 0.9rem;
  font-weight: 500;
  transition: color var(--transition), background var(--transition);
  white-space: nowrap;
}

.nav-link:hover,
.nav-link.active {
  color: #fff;
  background: rgba(255,255,255,0.1);
}

.nav-link.active::after {
  content: '';
  position: absolute;
  bottom: 0;
  left: 0;
  right: 0;
  height: 2px;
  background: var(--accent);
}

/* ============================================================
   5. 实时辟谣快讯跑马灯 (Ticker)
   ============================================================ */
.news-ticker {
  background: var(--secondary);
  color: #fff;
  padding: 8px 0;
  overflow: hidden;
}

.ticker-inner {
  display: flex;
  align-items: center;
  gap: var(--space-lg);
}

.ticker-label {
  flex-shrink: 0;
  background: var(--danger);
  color: #fff;
  padding: 2px 10px;
  border-radius: var(--radius-sm);
  font-size: 0.75rem;
  font-weight: 700;
  letter-spacing: 0.05em;
}

.ticker-track {
  flex: 1;
  overflow: hidden;
  position: relative;
}

.ticker-content {
  display: flex;
  gap: var(--space-3xl);
  animation: ticker-scroll 40s linear infinite;
  white-space: nowrap;
}

.ticker-content:hover {
  animation-play-state: paused;
}

.ticker-item {
  display: inline-flex;
  align-items: center;
  gap: var(--space-sm);
  font-size: 0.85rem;
  cursor: pointer;
  transition: color var(--transition);
}

.ticker-item:hover {
  color: #a5d6a7;
}

.ticker-badge {
  display: inline-block;
  padding: 1px 6px;
  border-radius: 3px;
  font-size: 0.7rem;
  font-weight: 700;
  background: var(--danger);
  color: #fff;
}

.ticker-badge.verified {
  background: var(--accent);
}

@keyframes ticker-scroll {
  0% { transform: translateX(0); }
  100% { transform: translateX(-50%); }
}

/* ============================================================
   6. 真假判定标签组件 (Fact-Check Stamp)
   ============================================================ */
.fc-stamp {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  padding: 4px 12px;
  border-radius: var(--radius-sm);
  font-size: 0.75rem;
  font-weight: 700;
  letter-spacing: 0.06em;
  text-transform: uppercase;
  font-family: var(--font-mono);
  border: 2px solid currentColor;
  position: relative;
  white-space: nowrap;
}

.fc-stamp--false {
  color: var(--danger);
  background: rgba(244,67,54,0.08);
}

.fc-stamp--true {
  color: var(--accent);
  background: rgba(76,175,80,0.08);
}

.fc-stamp--unverified {
  color: var(--warning);
  background: rgba(255,152,0,0.08);
}

.fc-stamp--misleading {
  color: #F9A825;
  background: rgba(249,168,37,0.08);
}

.fc-stamp--mixed {
  color: var(--mixed);
  background: rgba(156,39,176,0.08);
}

/* 大印章版本（文章详情页） */
.fc-stamp--large {
  font-size: 1rem;
  padding: 8px 20px;
  border-width: 3px;
  transform: rotate(-3deg);
  animation: stamp-appear 0.4s cubic-bezier(0.175, 0.885, 0.32, 1.275) forwards;
}

@keyframes stamp-appear {
  0% { transform: rotate(-3deg) scale(0.5); opacity: 0; }
  100% { transform: rotate(-3deg) scale(1); opacity: 1; }
}

/* 卡片角标版本 */
.fc-stamp--badge {
  position: absolute;
  top: var(--space-sm);
  left: var(--space-sm);
  font-size: 0.65rem;
  padding: 3px 8px;
  border-radius: var(--radius-sm);
  z-index: 2;
}

/* ============================================================
   7. 卡片组件
   ============================================================ */
.card {
  background: var(--card-bg);
  border-radius: var(--radius-md);
  box-shadow: var(--shadow-sm);
  border: 1px solid var(--border);
  overflow: hidden;
  transition: box-shadow var(--transition), transform var(--transition);
}

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

.card-thumb {
  position: relative;
  overflow: hidden;
  aspect-ratio: 16/9;
}

.card-thumb img {
  width: 100%;
  height: 100%;
  object-fit: cover;
  transition: transform var(--transition-slow);
}

.card:hover .card-thumb img {
  transform: scale(1.04);
}

.card-body {
  padding: var(--space-md);
}

.card-meta {
  display: flex;
  align-items: center;
  gap: var(--space-sm);
  margin-bottom: var(--space-sm);
  flex-wrap: wrap;
}

.card-category {
  font-size: 0.7rem;
  font-weight: 600;
  color: var(--text-muted);
  text-transform: uppercase;
  letter-spacing: 0.05em;
}

.card-date {
  font-size: 0.75rem;
  color: var(--text-muted);
  font-family: var(--font-mono);
}

.card-title {
  font-size: 1rem;
  font-weight: 700;
  line-height: 1.4;
  margin-bottom: var(--space-sm);
  color: var(--text);
  display: -webkit-box;
  -webkit-line-clamp: 2;
  -webkit-box-orient: vertical;
  overflow: hidden;
}

.card-title a {
  color: inherit;
}

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

.card-excerpt {
  font-size: 0.875rem;
  color: var(--text-muted);
  line-height: 1.6;
  display: -webkit-box;
  -webkit-line-clamp: 2;
  -webkit-box-orient: vertical;
  overflow: hidden;
  margin-bottom: var(--space-sm);
}

.card-footer {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: var(--space-sm) var(--space-md);
  border-top: 1px solid var(--border);
  font-size: 0.75rem;
  color: var(--text-muted);
}

.card-stats {
  display: flex;
  gap: var(--space-md);
}

.card-stat {
  display: flex;
  align-items: center;
  gap: 4px;
}

/* ============================================================
   8. 证据链展示面板 (Evidence Chain Panel)
   ============================================================ */
.evidence-chain {
  position: relative;
  padding-left: var(--space-xl);
}

.evidence-chain::before {
  content: '';
  position: absolute;
  left: 11px;
  top: 0;
  bottom: 0;
  width: 2px;
  background: linear-gradient(to bottom, var(--accent), var(--border));
}

.evidence-node {
  position: relative;
  margin-bottom: var(--space-xl);
  padding: var(--space-md) var(--space-lg);
  background: var(--card-bg);
  border-radius: var(--radius-md);
  border: 1px solid var(--border);
  box-shadow: var(--shadow-sm);
  transition: border-color var(--transition), box-shadow var(--transition);
}

.evidence-node.active {
  border-color: var(--accent);
  box-shadow: 0 0 0 3px rgba(76,175,80,0.15);
}

.evidence-node::before {
  content: '';
  position: absolute;
  left: calc(-1 * var(--space-xl) - 5px);
  top: var(--space-lg);
  width: 12px;
  height: 12px;
  border-radius: 50%;
  background: var(--accent);
  border: 2px solid var(--card-bg);
  box-shadow: 0 0 0 2px var(--accent);
}

.evidence-node-time {
  font-size: 0.75rem;
  color: var(--text-muted);
  font-family: var(--font-mono);
  margin-bottom: var(--space-xs);
}

.evidence-node-title {
  font-size: 0.95rem;
  font-weight: 700;
  color: var(--text);
  margin-bottom: var(--space-sm);
}

.evidence-node-content {
  font-size: 0.875rem;
  color: var(--text-muted);
  line-height: 1.6;
}

.evidence-node-img {
  margin-top: var(--space-sm);
  border-radius: var(--radius-sm);
  overflow: hidden;
  cursor: pointer;
}

.evidence-node-img img {
  width: 100%;
  max-height: 300px;
  object-fit: cover;
  transition: transform var(--transition);
}

.evidence-node-img:hover img {
  transform: scale(1.02);
}

/* ============================================================
   9. 核查进度条 (Investigation Progress Bar)
   ============================================================ */
.progress-track {
  display: flex;
  align-items: flex-start;
  gap: 0;
  position: relative;
  padding: var(--space-lg) 0;
}

.progress-track::before {
  content: '';
  position: absolute;
  top: calc(var(--space-lg) + 16px);
  left: 16px;
  right: 16px;
  height: 3px;
  background: var(--border);
  z-index: 0;
}

.progress-step {
  flex: 1;
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: var(--space-sm);
  position: relative;
  z-index: 1;
  cursor: pointer;
}

.progress-dot {
  width: 32px;
  height: 32px;
  border-radius: 50%;
  background: var(--border);
  border: 3px solid var(--card-bg);
  box-shadow: 0 0 0 2px var(--border);
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 0.75rem;
  font-weight: 700;
  color: var(--text-muted);
  transition: all var(--transition);
}

.progress-step.completed .progress-dot {
  background: var(--accent);
  box-shadow: 0 0 0 2px var(--accent);
  color: #fff;
}

.progress-step.active .progress-dot {
  background: var(--warning);
  box-shadow: 0 0 0 2px var(--warning);
  color: #fff;
  animation: pulse-dot 1.5s ease-in-out infinite;
}

@keyframes pulse-dot {
  0%, 100% { box-shadow: 0 0 0 2px var(--warning); }
  50% { box-shadow: 0 0 0 6px rgba(255,152,0,0.3); }
}

.progress-label {
  font-size: 0.75rem;
  color: var(--text-muted);
  text-align: center;
  max-width: 80px;
  line-height: 1.3;
}

.progress-step.completed .progress-label,
.progress-step.active .progress-label {
  color: var(--text);
  font-weight: 600;
}

/* 进度条填充线 */
.progress-track .progress-fill {
  position: absolute;
  top: calc(var(--space-lg) + 16px);
  left: 16px;
  height: 3px;
  background: var(--accent);
  z-index: 0;
  transition: width var(--transition-slow);
}

/* ============================================================
   10. 谣言传播路径图 (Rumor Propagation Map)
   ============================================================ */
.propagation-map {
  background: var(--card-bg);
  border-radius: var(--radius-lg);
  border: 1px solid var(--border);
  overflow: hidden;
  position: relative;
}

.propagation-map-canvas {
  width: 100%;
  height: 400px;
  display: block;
}

.propagation-tooltip {
  position: absolute;
  background: var(--primary);
  color: #fff;
  padding: var(--space-sm) var(--space-md);
  border-radius: var(--radius-md);
  font-size: 0.8rem;
  pointer-events: none;
  z-index: 10;
  max-width: 200px;
  box-shadow: var(--shadow-md);
  opacity: 0;
  transition: opacity var(--transition);
}

.propagation-tooltip.visible {
  opacity: 1;
}

/* ============================================================
   11. 专家评审卡片 (Expert Review Card)
   ============================================================ */
.expert-card {
  background: var(--card-bg);
  border-radius: var(--radius-md);
  border: 1px solid var(--border);
  padding: var(--space-lg);
  box-shadow: var(--shadow-sm);
  display: flex;
  gap: var(--space-md);
  transition: box-shadow var(--transition), transform var(--transition);
}

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

.expert-avatar {
  flex-shrink: 0;
  width: 64px;
  height: 64px;
  border-radius: 50%;
  overflow: hidden;
  border: 2px solid var(--border);
}

.expert-avatar img {
  width: 100%;
  height: 100%;
  object-fit: cover;
}

.expert-info {
  flex: 1;
}

.expert-name {
  font-size: 1rem;
  font-weight: 700;
  color: var(--text);
  margin-bottom: 2px;
}

.expert-name a {
  color: inherit;
}

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

.expert-title {
  font-size: 0.8rem;
  color: var(--text-muted);
  margin-bottom: var(--space-sm);
}

.expert-field {
  display: inline-block;
  padding: 2px 8px;
  background: rgba(55,71,79,0.08);
  color: var(--primary);
  border-radius: 50px;
  font-size: 0.7rem;
  font-weight: 600;
  margin-bottom: var(--space-sm);
}

.expert-quote {
  font-size: 0.875rem;
  color: var(--text-muted);
  line-height: 1.6;
  font-style: italic;
  border-left: 3px solid var(--accent);
  padding-left: var(--space-sm);
}

/* ============================================================
   12. 首页 Hero 区域
   ============================================================ */
.hero-section {
  position: relative;
  background: var(--primary);
  color: #fff;
  overflow: hidden;
}

.hero-bg {
  position: absolute;
  inset: 0;
  z-index: 0;
}

.hero-bg img {
  width: 100%;
  height: 100%;
  object-fit: cover;
  opacity: 0.25;
}

.hero-content {
  position: relative;
  z-index: 1;
  padding: var(--space-3xl) 0;
}

.hero-grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: var(--space-xl);
}

.hero-main {
  display: flex;
  flex-direction: column;
  gap: var(--space-md);
}

.hero-stamp-wrap {
  display: flex;
  align-items: center;
  gap: var(--space-md);
}

.hero-title {
  font-size: clamp(1.5rem, 4vw, 2.5rem);
  font-weight: 800;
  line-height: 1.2;
  color: #fff;
}

.hero-excerpt {
  font-size: 1rem;
  color: rgba(255,255,255,0.8);
  line-height: 1.7;
  max-width: 600px;
}

.hero-cta {
  display: inline-flex;
  align-items: center;
  gap: var(--space-sm);
  padding: 12px var(--space-xl);
  background: var(--accent);
  color: #fff;
  border-radius: 50px;
  font-weight: 700;
  font-size: 0.95rem;
  transition: background var(--transition), transform var(--transition);
  align-self: flex-start;
}

.hero-cta:hover {
  background: #388E3C;
  color: #fff;
  transform: translateY(-2px);
}

/* ============================================================
   13. 统计数据区
   ============================================================ */
.stats-bar {
  background: var(--secondary);
  color: #fff;
  padding: var(--space-lg) 0;
}

.stats-grid {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: var(--space-md);
}

.stat-item {
  text-align: center;
  padding: var(--space-md);
}

.stat-number {
  font-size: 2rem;
  font-weight: 800;
  font-family: var(--font-mono);
  color: var(--accent);
  display: block;
  line-height: 1;
  margin-bottom: 4px;
}

.stat-label {
  font-size: 0.8rem;
  color: rgba(255,255,255,0.7);
}

/* ============================================================
   14. 区块标题
   ============================================================ */
.section-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  margin-bottom: var(--space-xl);
  padding-bottom: var(--space-md);
  border-bottom: 2px solid var(--border);
}

.section-title {
  font-size: 1.375rem;
  font-weight: 800;
  color: var(--text);
  position: relative;
  padding-left: var(--space-md);
}

.section-title::before {
  content: '';
  position: absolute;
  left: 0;
  top: 0;
  bottom: 0;
  width: 4px;
  background: var(--primary);
  border-radius: 2px;
}

.section-link {
  font-size: 0.875rem;
  color: var(--primary);
  font-weight: 600;
  display: flex;
  align-items: center;
  gap: 4px;
}

.section-link:hover {
  color: var(--accent);
}

/* ============================================================
   15. 报告网格
   ============================================================ */
.reports-grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: var(--space-lg);
}

/* ============================================================
   16. 筛选标签栏
   ============================================================ */
.filter-bar {
  display: flex;
  align-items: center;
  gap: var(--space-sm);
  flex-wrap: wrap;
  margin-bottom: var(--space-xl);
}

.filter-btn {
  padding: 6px 16px;
  border-radius: 50px;
  font-size: 0.8rem;
  font-weight: 600;
  border: 1.5px solid var(--border);
  color: var(--text-muted);
  background: var(--card-bg);
  transition: all var(--transition);
  cursor: pointer;
}

.filter-btn:hover,
.filter-btn.active {
  border-color: var(--primary);
  color: var(--primary);
  background: rgba(55,71,79,0.06);
}

.filter-btn.filter-false.active {
  border-color: var(--danger);
  color: var(--danger);
  background: rgba(244,67,54,0.06);
}

.filter-btn.filter-true.active {
  border-color: var(--accent);
  color: var(--accent);
  background: rgba(76,175,80,0.06);
}

/* ============================================================
   17. 折叠面板 (Accordion)
   ============================================================ */
.accordion-item {
  border: 1px solid var(--border);
  border-radius: var(--radius-md);
  overflow: hidden;
  margin-bottom: var(--space-sm);
}

.accordion-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: var(--space-md) var(--space-lg);
  background: var(--card-bg);
  cursor: pointer;
  user-select: none;
  transition: background var(--transition);
}

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

.accordion-title {
  font-size: 0.95rem;
  font-weight: 600;
  color: var(--text);
}

.accordion-icon {
  width: 20px;
  height: 20px;
  display: flex;
  align-items: center;
  justify-content: center;
  transition: transform var(--transition);
  color: var(--text-muted);
  flex-shrink: 0;
}

.accordion-item.open .accordion-icon {
  transform: rotate(180deg);
}

.accordion-body {
  max-height: 0;
  overflow: hidden;
  transition: max-height 0.35s ease, padding var(--transition);
}

.accordion-item.open .accordion-body {
  max-height: 2000px;
}

.accordion-content {
  padding: var(--space-md) var(--space-lg);
  font-size: 0.9rem;
  color: var(--text-muted);
  line-height: 1.7;
  border-top: 1px solid var(--border);
}

/* ============================================================
   18. 灯箱 (Lightbox)
   ============================================================ */
.lightbox-overlay {
  position: fixed;
  inset: 0;
  background: rgba(0,0,0,0.92);
  z-index: 9999;
  display: flex;
  align-items: center;
  justify-content: center;
  opacity: 0;
  pointer-events: none;
  transition: opacity var(--transition);
}

.lightbox-overlay.active {
  opacity: 1;
  pointer-events: all;
}

.lightbox-img {
  max-width: 90vw;
  max-height: 90vh;
  object-fit: contain;
  border-radius: var(--radius-md);
  box-shadow: var(--shadow-lg);
}

.lightbox-close {
  position: absolute;
  top: var(--space-lg);
  right: var(--space-lg);
  color: #fff;
  font-size: 1.5rem;
  width: 44px;
  height: 44px;
  display: flex;
  align-items: center;
  justify-content: center;
  border-radius: 50%;
  background: rgba(255,255,255,0.1);
  transition: background var(--transition);
}

.lightbox-close:hover {
  background: rgba(255,255,255,0.2);
}

/* ============================================================
   19. 侧边栏
   ============================================================ */
.sidebar {
  display: flex;
  flex-direction: column;
  gap: var(--space-xl);
}

.sidebar-widget {
  background: var(--card-bg);
  border-radius: var(--radius-md);
  border: 1px solid var(--border);
  overflow: hidden;
}

.sidebar-widget-header {
  padding: var(--space-md) var(--space-lg);
  background: var(--primary);
  color: #fff;
  font-size: 0.9rem;
  font-weight: 700;
}

.sidebar-widget-body {
  padding: var(--space-md);
}

.sidebar-list-item {
  display: flex;
  gap: var(--space-sm);
  padding: var(--space-sm) 0;
  border-bottom: 1px solid var(--border);
}

.sidebar-list-item:last-child {
  border-bottom: none;
}

.sidebar-list-item .fc-stamp {
  flex-shrink: 0;
}

.sidebar-list-title {
  font-size: 0.85rem;
  color: var(--text);
  line-height: 1.4;
}

.sidebar-list-title a {
  color: inherit;
}

.sidebar-list-title a:hover {
  color: var(--primary);
}

/* ============================================================
   20. 文章详情页
   ============================================================ */
.article-header {
  padding: var(--space-2xl) 0 var(--space-xl);
}

.article-stamp-area {
  display: flex;
  align-items: center;
  gap: var(--space-lg);
  margin-bottom: var(--space-lg);
  flex-wrap: wrap;
}

.article-title {
  font-size: clamp(1.5rem, 3vw, 2.25rem);
  font-weight: 800;
  line-height: 1.25;
  color: var(--text);
  margin-bottom: var(--space-md);
}

.article-meta {
  display: flex;
  align-items: center;
  gap: var(--space-md);
  flex-wrap: wrap;
  font-size: 0.85rem;
  color: var(--text-muted);
  padding: var(--space-md) 0;
  border-top: 1px solid var(--border);
  border-bottom: 1px solid var(--border);
  margin-bottom: var(--space-xl);
}

.article-author {
  display: flex;
  align-items: center;
  gap: var(--space-xs);
  font-weight: 600;
  color: var(--text);
}

.article-cover {
  border-radius: var(--radius-lg);
  overflow: hidden;
  margin-bottom: var(--space-xl);
  aspect-ratio: 16/9;
}

.article-cover img {
  width: 100%;
  height: 100%;
  object-fit: cover;
}

/* 核查结论框 */
.verdict-box {
  border-radius: var(--radius-lg);
  padding: var(--space-xl);
  margin-bottom: var(--space-xl);
  position: relative;
  overflow: hidden;
}

.verdict-box--false {
  background: rgba(244,67,54,0.06);
  border: 2px solid rgba(244,67,54,0.3);
}

.verdict-box--true {
  background: rgba(76,175,80,0.06);
  border: 2px solid rgba(76,175,80,0.3);
}

.verdict-box--unverified {
  background: rgba(255,152,0,0.06);
  border: 2px solid rgba(255,152,0,0.3);
}

.verdict-title {
  font-size: 0.8rem;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 0.1em;
  color: var(--text-muted);
  margin-bottom: var(--space-sm);
}

.verdict-claim {
  font-size: 1.1rem;
  font-weight: 700;
  color: var(--text);
  line-height: 1.5;
  margin-bottom: var(--space-md);
  font-style: italic;
}

.verdict-conclusion {
  font-size: 0.95rem;
  color: var(--text);
  line-height: 1.7;
}

/* 正文样式 */
.article-body {
  font-size: 1.0625rem;
  line-height: 1.8;
  color: var(--text);
}

.article-body h2 {
  font-size: 1.375rem;
  font-weight: 800;
  margin: var(--space-2xl) 0 var(--space-md);
  color: var(--text);
  padding-left: var(--space-md);
  border-left: 4px solid var(--primary);
}

.article-body h3 {
  font-size: 1.125rem;
  font-weight: 700;
  margin: var(--space-xl) 0 var(--space-sm);
  color: var(--text);
}

.article-body p {
  margin-bottom: var(--space-md);
}

.article-body blockquote {
  border-left: 4px solid var(--accent);
  padding: var(--space-md) var(--space-lg);
  background: rgba(76,175,80,0.05);
  border-radius: 0 var(--radius-md) var(--radius-md) 0;
  margin: var(--space-lg) 0;
  font-style: italic;
  color: var(--text-muted);
}

.article-body .source-link {
  display: inline-flex;
  align-items: center;
  gap: 4px;
  color: var(--primary);
  font-size: 0.875rem;
  font-weight: 600;
  border-bottom: 1px dashed var(--primary);
}

.article-body .source-link:hover {
  color: var(--accent);
  border-color: var(--accent);
}

/* ============================================================
   21. 表单样式
   ============================================================ */
.form-group {
  margin-bottom: var(--space-lg);
}

.form-label {
  display: block;
  font-size: 0.9rem;
  font-weight: 600;
  color: var(--text);
  margin-bottom: var(--space-sm);
}

.form-label .required {
  color: var(--danger);
  margin-left: 2px;
}

.form-control {
  width: 100%;
  padding: 10px var(--space-md);
  border: 1.5px solid var(--border);
  border-radius: var(--radius-md);
  font-size: 0.95rem;
  color: var(--text);
  background: var(--card-bg);
  transition: border-color var(--transition), box-shadow var(--transition);
  outline: none;
}

.form-control:focus {
  border-color: var(--primary);
  box-shadow: 0 0 0 3px rgba(55,71,79,0.12);
}

textarea.form-control {
  resize: vertical;
  min-height: 120px;
  line-height: 1.6;
}

.form-hint {
  font-size: 0.8rem;
  color: var(--text-muted);
  margin-top: var(--space-xs);
}

.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: var(--space-sm);
  padding: 12px var(--space-xl);
  border-radius: var(--radius-md);
  font-size: 0.95rem;
  font-weight: 700;
  transition: all var(--transition);
  cursor: pointer;
  border: 2px solid transparent;
}

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

.btn-primary:hover {
  background: var(--secondary);
  border-color: var(--secondary);
  color: #fff;
  transform: translateY(-1px);
  box-shadow: var(--shadow-md);
}

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

.btn-danger:hover {
  background: #d32f2f;
  border-color: #d32f2f;
  color: #fff;
}

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

.btn-outline:hover {
  background: var(--primary);
  color: #fff;
}

/* ============================================================
   22. 分页
   ============================================================ */
.pagination {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: var(--space-xs);
  margin-top: var(--space-2xl);
}

.page-btn {
  width: 40px;
  height: 40px;
  display: flex;
  align-items: center;
  justify-content: center;
  border-radius: var(--radius-md);
  font-size: 0.9rem;
  font-weight: 600;
  color: var(--text-muted);
  border: 1.5px solid var(--border);
  background: var(--card-bg);
  transition: all var(--transition);
  cursor: pointer;
}

.page-btn:hover,
.page-btn.active {
  background: var(--primary);
  color: #fff;
  border-color: var(--primary);
}

/* ============================================================
   23. 面包屑
   ============================================================ */
.breadcrumb {
  display: flex;
  align-items: center;
  gap: var(--space-xs);
  font-size: 0.85rem;
  color: var(--text-muted);
  padding: var(--space-md) 0;
  flex-wrap: wrap;
}

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

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

.breadcrumb-sep {
  color: var(--border);
}

/* ============================================================
   24. 页脚 (Footer)
   ============================================================ */
.site-footer {
  background: var(--primary);
  color: rgba(255,255,255,0.8);
  padding: var(--space-3xl) 0 0;
  margin-top: var(--space-3xl);
}

.footer-grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: var(--space-2xl);
  padding-bottom: var(--space-2xl);
  border-bottom: 1px solid rgba(255,255,255,0.1);
}

.footer-brand .site-logo {
  margin-bottom: var(--space-md);
}

.footer-desc {
  font-size: 0.875rem;
  line-height: 1.7;
  color: rgba(255,255,255,0.65);
  margin-bottom: var(--space-md);
}

.footer-mission {
  font-size: 0.85rem;
  font-style: italic;
  color: rgba(255,255,255,0.5);
  padding: var(--space-sm) var(--space-md);
  border-left: 3px solid var(--accent);
}

.footer-col-title {
  font-size: 0.85rem;
  font-weight: 700;
  color: #fff;
  text-transform: uppercase;
  letter-spacing: 0.08em;
  margin-bottom: var(--space-md);
}

.footer-links {
  display: flex;
  flex-direction: column;
  gap: var(--space-sm);
}

.footer-links a {
  font-size: 0.875rem;
  color: rgba(255,255,255,0.65);
  transition: color var(--transition);
}

.footer-links a:hover {
  color: #fff;
}

.social-links {
  display: flex;
  gap: var(--space-sm);
  flex-wrap: wrap;
}

.social-link {
  width: 36px;
  height: 36px;
  border-radius: 50%;
  background: rgba(255,255,255,0.1);
  display: flex;
  align-items: center;
  justify-content: center;
  color: rgba(255,255,255,0.7);
  font-size: 0.9rem;
  transition: background var(--transition), color var(--transition);
}

.social-link:hover {
  background: var(--accent);
  color: #fff;
}

.footer-bottom {
  padding: var(--space-lg) 0;
  display: flex;
  align-items: center;
  justify-content: space-between;
  flex-wrap: wrap;
  gap: var(--space-md);
  font-size: 0.8rem;
  color: rgba(255,255,255,0.45);
}

.footer-bottom a {
  color: rgba(255,255,255,0.6);
}

.footer-bottom a:hover {
  color: #fff;
}

/* ============================================================
   25. PWA 安装提示
   ============================================================ */
.pwa-install-banner {
  position: fixed;
  bottom: var(--space-lg);
  left: 50%;
  transform: translateX(-50%) translateY(120%);
  background: var(--primary);
  color: #fff;
  padding: var(--space-md) var(--space-xl);
  border-radius: var(--radius-lg);
  box-shadow: var(--shadow-lg);
  display: flex;
  align-items: center;
  gap: var(--space-md);
  z-index: 9000;
  transition: transform var(--transition-slow);
  max-width: calc(100vw - var(--space-2xl));
  width: 400px;
}

.pwa-install-banner.visible {
  transform: translateX(-50%) translateY(0);
}

.pwa-install-text {
  flex: 1;
  font-size: 0.875rem;
}

.pwa-install-text strong {
  display: block;
  font-size: 0.95rem;
  margin-bottom: 2px;
}

.pwa-install-btn {
  padding: 8px 16px;
  background: var(--accent);
  color: #fff;
  border-radius: var(--radius-md);
  font-size: 0.85rem;
  font-weight: 700;
  white-space: nowrap;
}

.pwa-install-dismiss {
  color: rgba(255,255,255,0.6);
  font-size: 1.2rem;
  line-height: 1;
}

/* ============================================================
   26. 搜索结果页
   ============================================================ */
.search-hero {
  background: var(--primary);
  padding: var(--space-2xl) 0;
}

.search-hero-form {
  display: flex;
  align-items: center;
  background: #fff;
  border-radius: var(--radius-lg);
  overflow: hidden;
  box-shadow: var(--shadow-lg);
  max-width: 680px;
  margin: 0 auto;
}

.search-hero-input {
  flex: 1;
  padding: 16px var(--space-xl);
  border: none;
  font-size: 1.1rem;
  color: var(--text);
  outline: none;
}

.search-hero-btn {
  padding: 16px var(--space-xl);
  background: var(--accent);
  color: #fff;
  font-size: 1rem;
  font-weight: 700;
  transition: background var(--transition);
}

.search-hero-btn:hover {
  background: #388E3C;
}

.search-result-item {
  background: var(--card-bg);
  border: 1px solid var(--border);
  border-radius: var(--radius-md);
  padding: var(--space-lg);
  margin-bottom: var(--space-md);
  display: flex;
  gap: var(--space-lg);
  transition: box-shadow var(--transition);
}

.search-result-item:hover {
  box-shadow: var(--shadow-md);
}

.search-result-thumb {
  flex-shrink: 0;
  width: 120px;
  height: 80px;
  border-radius: var(--radius-sm);
  overflow: hidden;
}

.search-result-thumb img {
  width: 100%;
  height: 100%;
  object-fit: cover;
}

.search-result-body {
  flex: 1;
}

.search-result-title {
  font-size: 1rem;
  font-weight: 700;
  color: var(--text);
  margin-bottom: var(--space-xs);
  line-height: 1.4;
}

.search-result-title a {
  color: inherit;
}

.search-result-title a:hover {
  color: var(--primary);
}

.search-result-excerpt {
  font-size: 0.875rem;
  color: var(--text-muted);
  line-height: 1.6;
  display: -webkit-box;
  -webkit-line-clamp: 2;
  -webkit-box-orient: vertical;
  overflow: hidden;
}

/* ============================================================
   27. 响应式设计（Mobile-First）
   ============================================================ */

/* 平板 (≥ 640px) */
@media (min-width: 640px) {
  .stats-grid {
    grid-template-columns: repeat(4, 1fr);
  }

  .reports-grid {
    grid-template-columns: repeat(2, 1fr);
  }

  .footer-grid {
    grid-template-columns: repeat(2, 1fr);
  }
}

/* 桌面 (≥ 1024px) */
@media (min-width: 1024px) {
  .container {
    padding: 0 var(--space-xl);
  }

  .hero-grid {
    grid-template-columns: 3fr 2fr;
    align-items: center;
  }

  .reports-grid {
    grid-template-columns: repeat(3, 1fr);
  }

  .reports-grid--4col {
    grid-template-columns: repeat(4, 1fr);
  }

  .footer-grid {
    grid-template-columns: 2fr 1fr 1fr 1fr;
  }

  .article-layout {
    display: grid;
    grid-template-columns: 1fr 320px;
    gap: var(--space-2xl);
    align-items: flex-start;
  }

  .menu-toggle {
    display: none;
  }

  .main-nav {
    display: block !important;
  }
}

/* 移动端导航 */
@media (max-width: 1023px) {
  .menu-toggle {
    display: flex;
  }

  .main-nav {
    display: none;
  }

  .main-nav.open {
    display: block;
  }

  .nav-list {
    flex-direction: column;
    padding: var(--space-sm) 0;
  }

  .nav-link {
    padding: 12px var(--space-lg);
  }

  .header-search {
    display: none;
  }

  .hero-content {
    padding: var(--space-2xl) 0;
  }

  .search-result-item {
    flex-direction: column;
  }

  .search-result-thumb {
    width: 100%;
    height: 180px;
  }
}

@media (max-width: 640px) {
  .header-top {
    flex-wrap: wrap;
  }

  .btn-submit-tip span {
    display: none;
  }

  .progress-track {
    flex-direction: column;
    padding-left: var(--space-xl);
  }

  .progress-track::before {
    top: 16px;
    left: 16px;
    bottom: 16px;
    right: auto;
    width: 3px;
    height: auto;
  }

  .progress-fill {
    display: none;
  }

  .progress-step {
    flex-direction: row;
    align-items: center;
    gap: var(--space-md);
  }

  .progress-label {
    text-align: left;
    max-width: none;
  }
}

/* ============================================================
   28. 打印样式
   ============================================================ */
@media print {
  .site-header,
  .news-ticker,
  .site-footer,
  .sidebar,
  .pwa-install-banner {
    display: none;
  }

  body {
    font-size: 12pt;
    color: #000;
    background: #fff;
  }

  .article-body {
    max-width: 100%;
  }
}

/* ============================================================
   29. 无障碍访问
   ============================================================ */
:focus-visible {
  outline: 3px solid var(--accent);
  outline-offset: 2px;
}

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

/* 高对比度模式 */
@media (prefers-contrast: high) {
  :root {
    --border: #000;
    --text-muted: #333;
  }
}