:root {
  --primary: #4F46E5;
  --primary-light: #EEF2FF;
  --text: #1E293B;
  --text-secondary: #64748B;
  --border: #E2E8F0;
  --bg: #F8FAFC;
  --card: #FFFFFF;
}

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

body {
  font-family: "Microsoft YaHei", "PingFang SC", -apple-system, sans-serif;
  color: var(--text);
  background: var(--bg);
  line-height: 1.75;
}

nav {
  background: var(--card);
  border-bottom: 1px solid var(--border);
  position: sticky;
  top: 0;
  z-index: 100;
}
nav .inner {
  max-width: 960px;
  margin: 0 auto;
  padding: 0 24px;
  height: 56px;
  display: flex;
  align-items: center;
  gap: 32px;
}
nav .logo {
  font-weight: bold;
  font-size: 17px;
  color: var(--primary);
  text-decoration: none;
}
nav a.nav-link {
  color: var(--text-secondary);
  text-decoration: none;
  font-size: 15px;
  padding: 4px 2px;
  border-bottom: 2px solid transparent;
}
nav a.nav-link:hover { color: var(--primary); }
nav a.nav-link.active {
  color: var(--primary);
  border-bottom-color: var(--primary);
  font-weight: 600;
}

.container {
  max-width: 960px;
  margin: 0 auto;
  padding: 40px 24px 80px;
}

.hero {
  background: linear-gradient(135deg, #4F46E5 0%, #7C3AED 100%);
  color: #fff;
  border-radius: 16px;
  padding: 48px 40px;
  margin-bottom: 40px;
}
.hero h1 { font-size: 30px; margin-bottom: 14px; }
.hero p.subtitle { font-size: 16px; opacity: 0.92; max-width: 640px; }
.hero .tags { margin-top: 20px; display: flex; flex-wrap: wrap; gap: 8px; }
.hero .tag {
  background: rgba(255,255,255,0.18);
  border: 1px solid rgba(255,255,255,0.35);
  border-radius: 999px;
  padding: 3px 14px;
  font-size: 13px;
}

.card {
  background: var(--card);
  border: 1px solid var(--border);
  border-radius: 12px;
  padding: 28px 32px;
  margin-bottom: 28px;
}
.card h2 {
  font-size: 21px;
  margin-bottom: 16px;
  padding-bottom: 10px;
  border-bottom: 2px solid var(--primary-light);
}
.card h2 .num { color: var(--primary); margin-right: 8px; }
.card h3 { font-size: 17px; margin: 20px 0 8px; }
.card p { margin: 10px 0; }
.card ul, .card ol { margin: 10px 0 10px 24px; }
.card li { margin: 6px 0; }

.arch-img {
  width: 100%;
  background: #fff;
  border: 1px solid var(--border);
  border-radius: 10px;
  padding: 16px;
  margin: 12px 0;
}

.video-placeholder {
  background: var(--primary-light);
  border: 2px dashed #A5B4FC;
  border-radius: 12px;
  padding: 48px 24px;
  text-align: center;
  color: var(--primary);
}
.video-placeholder .icon { font-size: 40px; margin-bottom: 10px; }

.btn-row { display: flex; gap: 14px; flex-wrap: wrap; margin-top: 8px; }
.btn {
  display: inline-block;
  background: var(--primary);
  color: #fff;
  text-decoration: none;
  padding: 10px 26px;
  border-radius: 8px;
  font-size: 15px;
}
.btn:hover { background: #4338CA; }
.btn.secondary {
  background: #fff;
  color: var(--primary);
  border: 1px solid var(--primary);
}
.btn.secondary:hover { background: var(--primary-light); }

.metric-row {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(160px, 1fr));
  gap: 14px;
  margin: 16px 0;
}
.metric {
  background: var(--primary-light);
  border-radius: 10px;
  padding: 16px;
  text-align: center;
}
.metric .value { font-size: 24px; font-weight: bold; color: var(--primary); }
.metric .label { font-size: 13px; color: var(--text-secondary); margin-top: 4px; }

.callout {
  background: #FFFBEB;
  border-left: 4px solid #F59E0B;
  border-radius: 0 8px 8px 0;
  padding: 14px 18px;
  margin: 14px 0;
  font-size: 14.5px;
}
.callout.info {
  background: #F0F9FF;
  border-left-color: #0EA5E9;
}

/* 报告页样式 */
.report-meta {
  display: flex;
  gap: 10px;
  flex-wrap: wrap;
  margin: 12px 0 20px;
}
.report-meta .pill {
  background: var(--primary-light);
  color: var(--primary);
  border-radius: 999px;
  padding: 3px 14px;
  font-size: 13px;
  font-weight: 600;
}
.report-body h1 { font-size: 22px; margin: 24px 0 12px; }
.report-body h3 {
  font-size: 17px;
  margin: 26px 0 10px;
  padding-left: 10px;
  border-left: 4px solid var(--primary);
}
.report-body p { margin: 8px 0; }
.report-body ul, .report-body ol { margin: 8px 0 8px 22px; }
.report-body li { margin: 5px 0; }
.report-body table {
  width: 100%;
  border-collapse: collapse;
  margin: 14px 0;
  font-size: 14.5px;
}
.report-body th, .report-body td {
  border: 1px solid var(--border);
  padding: 8px 12px;
}
.report-body th { background: var(--primary-light); }
.report-body blockquote {
  background: #F1F5F9;
  border-left: 4px solid #94A3B8;
  padding: 12px 16px;
  margin: 14px 0;
  border-radius: 0 8px 8px 0;
  color: #475569;
  font-size: 14.5px;
}
.report-body code {
  background: var(--primary-light);
  color: var(--primary);
  padding: 1px 7px;
  border-radius: 5px;
  font-size: 13.5px;
}

.toc {
  background: var(--primary-light);
  border-radius: 10px;
  padding: 18px 24px;
  margin-bottom: 28px;
  font-size: 14.5px;
}
.toc a { color: var(--primary); text-decoration: none; }
.toc a:hover { text-decoration: underline; }
.toc ol { margin-left: 20px; }

/* 报告页签 */
.tab-bar {
  display: flex;
  gap: 10px;
  flex-wrap: wrap;
  margin-bottom: 20px;
}
.tab-btn {
  background: #fff;
  border: 1px solid var(--border);
  border-radius: 10px;
  padding: 10px 20px;
  font-size: 15px;
  cursor: pointer;
  color: var(--text-secondary);
  font-family: inherit;
  transition: all 0.15s;
}
.tab-btn:hover { border-color: var(--primary); color: var(--primary); }
.tab-btn.active {
  background: var(--primary);
  border-color: var(--primary);
  color: #fff;
  font-weight: 600;
}
.tab-btn .score { font-size: 13px; opacity: 0.85; margin-left: 6px; }
.report-pane { display: none; }
.report-pane.active { display: block; }

/* 报告内章节导航 */
.chapter-nav {
  background: var(--primary-light);
  border-radius: 10px;
  padding: 14px 18px;
  margin: 4px 0 18px;
  display: flex;
  flex-wrap: wrap;
  gap: 6px 16px;
  align-items: center;
  font-size: 14px;
  scroll-margin-top: 70px;
}
.chapter-nav-label { font-weight: 600; color: var(--primary); }
.chapter-nav a { color: var(--text); text-decoration: none; }
.chapter-nav a:hover { color: var(--primary); text-decoration: underline; }
.report-body h3 { scroll-margin-top: 70px; }
.back-to-nav {
  display: block;
  text-align: right;
  font-size: 13px;
  color: var(--text-secondary);
  text-decoration: none;
  margin: 2px 0 10px;
}
.back-to-nav:hover { color: var(--primary); }

footer {
  text-align: center;
  color: var(--text-secondary);
  font-size: 13px;
  padding: 32px 0;
  border-top: 1px solid var(--border);
  margin-top: 40px;
}