/*
 * ================================================================
 * Legal Report Theme — 法律报告页面通用样式
 * ================================================================
 * 风格：仿古纸张 + 金色调，专业法律/研究报告用途
 * 字体：Noto Serif SC（标题）+ Noto Sans SC（正文）
 * 使用方式：在 HTML <head> 中引入本文件
 *   <link rel="preconnect" href="https://fonts.googleapis.com">
 *   <link href="https://fonts.googleapis.com/css2?family=Noto+Serif+SC:wght@400;600;700&family=Noto+Sans+SC:wght@300;400;500;700&display=swap" rel="stylesheet">
 *   <link rel="stylesheet" href="legal-report-theme.css">
 * ================================================================
 */

/* ── CSS 变量（配色系统） ── */
:root {
  --ink: #1a1614;               /* 主文字色（近黑） */
  --ink-mid: #3d3530;           /* 正文文字色 */
  --ink-light: #6b6058;         /* 次要文字色 */
  --ink-muted: #9e9690;         /* 辅助说明色 */
  --parchment: #f8fbff;         /* 页面背景 */
  --parchment-deep: #dce8f6;    /* 卡片/区块背景 */
  --gold: #102a56;              /* 主强调色（藏蓝） */
  --gold-light: #2559a0;        /* 次强调色（亮蓝） */
  --gold-pale: #e0ecfa;         /* 浅蓝填充（引用背景） */
  --red-accent: #8b2020;        /* 备用强调色（深红） */
  --border: rgba(16, 42, 86, 0.2);      /* 默认边框 */
  --border-strong: rgba(16, 42, 86, 0.4); /* 强边框 */
}

/* ── Reset ── */
* { box-sizing: border-box; margin: 0; padding: 0; }
html { scroll-behavior: smooth; }

/* ── 全局基础 ── */
body {
  font-family: 'Noto Sans SC', 'PingFang SC', 'Microsoft YaHei', sans-serif;
  background: var(--parchment);
  color: var(--ink);
  font-size: 15px;
  line-height: 1.8;
}

/* ════════════════════════════════════
   导航栏 Navigation
   用法：<nav> <span class="nav-brand"> + <ul class="nav-links">
   ════════════════════════════════════ */
nav {
  position: fixed;
  top: 0; left: 0; right: 0;
  z-index: 100;
  background: rgba(248, 251, 255, 0.96);
  border-bottom: 0.5px solid var(--border-strong);
  padding: 0 2rem;
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: 56px;
  backdrop-filter: blur(8px);
}

.nav-brand {
  font-family: 'Noto Serif SC', serif;
  font-size: 13px;
  font-weight: 600;
  color: var(--gold);
  letter-spacing: 0.05em;
  white-space: nowrap;
}

.nav-links {
  display: flex;
  gap: 1.5rem;
  list-style: none;
}

.nav-links a {
  font-size: 12px;
  color: var(--ink-light);
  text-decoration: none;
  letter-spacing: 0.03em;
  transition: color 0.2s;
}

.nav-links a:hover { color: var(--gold); }

/* ════════════════════════════════════
   Hero 区域
   用法：<header class="hero">
     <div class="report-label">联合研究报告</div>
     <h1>标题</h1>
     <p class="hero-subtitle">副标题</p>
     <div class="meta-row"><span>信息</span>...</div>
   </header>
   ════════════════════════════════════ */
.hero {
  padding: 120px 2rem 80px;
  max-width: 900px;
  margin: 0 auto;
  text-align: center;
  position: relative;
}

.hero::before {
  content: '';
  position: absolute;
  top: 80px; left: 50%; transform: translateX(-50%);
  width: 1px;
  height: 40px;
  background: linear-gradient(to bottom, transparent, var(--border-strong));
}

.report-label {
  display: inline-block;
  font-size: 11px;
  letter-spacing: 0.15em;
  color: var(--gold);
  border: 0.5px solid var(--border-strong);
  padding: 4px 14px;
  margin-bottom: 2rem;
  text-transform: uppercase;
}

h1 {
  font-family: 'Noto Serif SC', serif;
  font-size: clamp(24px, 4vw, 40px);
  font-weight: 700;
  color: var(--ink);
  line-height: 1.3;
  letter-spacing: -0.01em;
  margin-bottom: 1rem;
}

.hero-subtitle {
  font-size: 14px;
  color: var(--ink-light);
  margin-bottom: 2.5rem;
  font-family: 'Noto Serif SC', serif;
}

.meta-row {
  display: flex;
  justify-content: center;
  gap: 2rem;
  font-size: 12px;
  color: var(--ink-muted);
  letter-spacing: 0.03em;
  border-top: 0.5px solid var(--border);
  border-bottom: 0.5px solid var(--border);
  padding: 14px 0;
  flex-wrap: wrap;
}

.meta-row span::before {
  content: '— ';
  color: var(--border-strong);
}

/* ════════════════════════════════════
   布局容器
   ════════════════════════════════════ */
.container {
  max-width: 900px;
  margin: 0 auto;
  padding: 0 2rem;
}

/* ════════════════════════════════════
   目录 Table of Contents
   用法：<div class="toc-section">
     <div class="toc-title">目录</div>
     <div class="toc-grid">
       <a href="#id" class="toc-item">
         <span class="toc-num">第X章</span>标题
       </a>
     </div>
   </div>
   ════════════════════════════════════ */
.toc-section {
  background: var(--parchment-deep);
  border: 0.5px solid var(--border);
  padding: 2rem 2.5rem;
  margin: 3rem 0;
}

.toc-title {
  font-size: 11px;
  letter-spacing: 0.12em;
  color: var(--gold);
  text-transform: uppercase;
  margin-bottom: 1.5rem;
  font-family: 'Noto Sans SC', sans-serif;
  font-weight: 500;
}

.toc-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 0.5rem 3rem;
}

.toc-item {
  display: flex;
  gap: 1rem;
  align-items: baseline;
  font-size: 13px;
  text-decoration: none;
  color: var(--ink-mid);
  padding: 4px 0;
  border-bottom: 0.5px dashed var(--border);
  transition: color 0.2s;
}

.toc-item:hover { color: var(--gold); }

.toc-num {
  font-size: 11px;
  color: var(--gold-light);
  font-family: 'Noto Serif SC', serif;
  flex-shrink: 0;
  width: 2rem;
}

/* ════════════════════════════════════
   章节 Chapter
   用法：<section class="chapter" id="ch1">
     <div class="chapter-header">
       <span class="chapter-num">第一章</span>
       <h2>章节标题</h2>
     </div>
     内容...
   </section>
   ════════════════════════════════════ */
.chapter {
  padding: 4rem 0 2rem;
  border-top: 1px solid var(--border);
}

.chapter-header {
  margin-bottom: 2.5rem;
}

.chapter-num {
  font-size: 11px;
  letter-spacing: 0.12em;
  color: var(--gold);
  text-transform: uppercase;
  font-family: 'Noto Sans SC', sans-serif;
  font-weight: 500;
  display: block;
  margin-bottom: 0.5rem;
}

h2 {
  font-family: 'Noto Serif SC', serif;
  font-size: clamp(20px, 2.5vw, 28px);
  font-weight: 700;
  color: var(--ink);
  line-height: 1.3;
  letter-spacing: -0.01em;
}

h3 {
  font-family: 'Noto Serif SC', serif;
  font-size: 17px;
  font-weight: 600;
  color: var(--ink-mid);
  margin: 2rem 0 0.75rem;
  padding-left: 1rem;
  border-left: 2px solid var(--gold-light);
}

h4 {
  font-size: 14px;
  font-weight: 500;
  color: var(--ink-mid);
  margin: 1.5rem 0 0.5rem;
}

p {
  font-size: 14px;
  color: var(--ink-mid);
  line-height: 1.9;
  margin-bottom: 1rem;
}

/* ════════════════════════════════════
   引言块 Pull Quote
   用法：<div class="pull-quote"><p>引用内容</p></div>
   ════════════════════════════════════ */
.pull-quote {
  border-left: 3px solid var(--gold);
  padding: 1rem 1.5rem;
  margin: 2rem 0;
  background: var(--gold-pale);
}

.pull-quote p {
  font-family: 'Noto Serif SC', serif;
  font-size: 15px;
  color: var(--ink);
  font-style: italic;
  margin: 0;
}

/* ════════════════════════════════════
   要点列表 Key Points
   用法：<div class="key-points">
     <div class="key-points-label">标签文字</div>
     <div class="key-point-item">
       <div class="key-point-dot"></div>
       <span>内容</span>
     </div>
   </div>
   ════════════════════════════════════ */
.key-points {
  background: var(--parchment-deep);
  border: 0.5px solid var(--border);
  padding: 1.5rem 2rem;
  margin: 2rem 0;
}

.key-points-label {
  font-size: 11px;
  letter-spacing: 0.1em;
  color: var(--gold);
  text-transform: uppercase;
  font-weight: 500;
  margin-bottom: 1rem;
}

.key-point-item {
  display: flex;
  gap: 0.75rem;
  margin-bottom: 0.6rem;
  font-size: 13.5px;
  color: var(--ink-mid);
  line-height: 1.7;
}

.key-point-dot {
  width: 5px;
  height: 5px;
  background: var(--gold);
  border-radius: 50%;
  flex-shrink: 0;
  margin-top: 9px;
}

/* ════════════════════════════════════
   能力卡片网格 Capability Grid
   用法：<div class="capability-grid">
     <div class="capability-card">
       <div class="cap-number">01</div>
       <div class="cap-title">标题</div>
       <div class="cap-desc">描述</div>
     </div>
   </div>
   ════════════════════════════════════ */
.capability-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
  gap: 1px;
  background: var(--border);
  border: 0.5px solid var(--border);
  margin: 2rem 0;
  overflow: hidden;
}

.capability-card {
  background: var(--parchment);
  padding: 1.5rem;
}

.cap-number {
  font-family: 'Noto Serif SC', serif;
  font-size: 28px;
  font-weight: 700;
  line-height: 1;
  margin-bottom: 0.5rem;
  color: var(--border-strong);
}

.cap-title {
  font-size: 13px;
  font-weight: 500;
  color: var(--gold);
  margin-bottom: 0.5rem;
}

.cap-desc {
  font-size: 12.5px;
  color: var(--ink-light);
  line-height: 1.7;
}

/* ════════════════════════════════════
   时间轴 Timeline
   用法：<div class="timeline">
     <div class="timeline-item">
       <div class="timeline-period">时间段</div>
       <div class="timeline-title">标题</div>
       <div class="timeline-desc">描述</div>
     </div>
   </div>
   ════════════════════════════════════ */
.timeline {
  margin: 2rem 0;
  position: relative;
  padding-left: 2rem;
}

.timeline::before {
  content: '';
  position: absolute;
  left: 0; top: 8px; bottom: 8px;
  width: 1px;
  background: var(--border-strong);
}

.timeline-item {
  position: relative;
  margin-bottom: 2rem;
  padding-left: 1.5rem;
}

.timeline-item::before {
  content: '';
  position: absolute;
  left: -2rem;
  top: 6px;
  width: 8px; height: 8px;
  border-radius: 50%;
  background: var(--gold);
  border: 2px solid var(--parchment);
  outline: 1px solid var(--gold);
}

.timeline-period {
  font-size: 11px;
  letter-spacing: 0.1em;
  color: var(--gold);
  font-weight: 500;
  margin-bottom: 0.3rem;
}

.timeline-title {
  font-size: 14px;
  font-weight: 500;
  color: var(--ink);
  margin-bottom: 0.4rem;
}

.timeline-desc {
  font-size: 13px;
  color: var(--ink-light);
  line-height: 1.7;
}

/* ════════════════════════════════════
   服务领域卡片 Service Domains
   用法：<div class="service-domains">
     <div class="service-domain">
       <span class="sd-icon">字</span>
       <div class="sd-title">标题</div>
       <div class="sd-desc">描述</div>
     </div>
   </div>
   ════════════════════════════════════ */
.service-domains {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
  gap: 1rem;
  margin: 2rem 0;
}

.service-domain {
  border: 0.5px solid var(--border-strong);
  padding: 1.25rem;
  position: relative;
  overflow: hidden;
}

.service-domain::after {
  content: '';
  position: absolute;
  bottom: 0; left: 0; right: 0;
  height: 2px;
  background: var(--gold);
  transform: scaleX(0);
  transform-origin: left;
  transition: transform 0.3s ease;
}

.service-domain:hover::after { transform: scaleX(1); }

.sd-icon {
  font-size: 22px;
  margin-bottom: 0.75rem;
  display: block;
  color: var(--gold);
  font-family: 'Noto Serif SC', serif;
  font-weight: 700;
}

.sd-title {
  font-size: 13px;
  font-weight: 500;
  color: var(--ink);
  margin-bottom: 0.4rem;
}

.sd-desc {
  font-size: 12px;
  color: var(--ink-light);
  line-height: 1.6;
}

/* ════════════════════════════════════
   客户画像卡片 Client Cards
   用法：<div class="client-grid">
     <div class="client-card">
       <div class="client-type">类型标签</div>
       <div class="client-name">客户名称</div>
       <ul class="client-needs">
         <li>需求项</li>
       </ul>
     </div>
   </div>
   ════════════════════════════════════ */
.client-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(260px, 1fr));
  gap: 1.5rem;
  margin: 2rem 0;
}

.client-card {
  border: 0.5px solid var(--border);
  padding: 1.5rem;
  background: var(--parchment);
}

.client-type {
  font-size: 11px;
  letter-spacing: 0.1em;
  color: var(--gold);
  text-transform: uppercase;
  font-weight: 500;
  margin-bottom: 0.5rem;
}

.client-name {
  font-family: 'Noto Serif SC', serif;
  font-size: 16px;
  font-weight: 600;
  color: var(--ink);
  margin-bottom: 1rem;
  padding-bottom: 0.75rem;
  border-bottom: 0.5px solid var(--border);
}

.client-needs {
  list-style: none;
  font-size: 12.5px;
  color: var(--ink-light);
  line-height: 1.7;
}

.client-needs li {
  padding: 3px 0;
  padding-left: 1rem;
  position: relative;
}

.client-needs li::before {
  content: '›';
  position: absolute;
  left: 0;
  color: var(--gold-light);
}

/* ════════════════════════════════════
   数据统计横幅 Stats Banner
   用法：<div class="stats-banner">
     <div class="stat-cell">
       <div class="stat-number">42%</div>
       <div class="stat-label">说明文字</div>
     </div>
   </div>
   ════════════════════════════════════ */
.stats-banner {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 1px;
  background: var(--border-strong);
  border: 0.5px solid var(--border-strong);
  margin: 3rem 0;
  overflow: hidden;
}

.stat-cell {
  background: var(--parchment-deep);
  padding: 1.5rem;
  text-align: center;
}

.stat-number {
  font-family: 'Noto Serif SC', serif;
  font-size: 32px;
  font-weight: 700;
  color: var(--gold);
  line-height: 1;
  margin-bottom: 0.4rem;
}

.stat-label {
  font-size: 12px;
  color: var(--ink-light);
  letter-spacing: 0.03em;
}

/* ════════════════════════════════════
   趋势列表 Trend List
   用法：<div class="trend-list">
     <div class="trend-item">
       <div class="trend-num">01</div>
       <div>
         <div class="trend-content-title">标题</div>
         <div class="trend-content-desc">描述</div>
       </div>
     </div>
   </div>
   ════════════════════════════════════ */
.trend-list {
  display: grid;
  gap: 1rem;
  margin: 2rem 0;
}

.trend-item {
  display: grid;
  grid-template-columns: 56px 1fr;
  gap: 1.25rem;
  align-items: start;
  padding: 1.25rem;
  border: 0.5px solid var(--border);
  background: var(--parchment);
  transition: border-color 0.2s;
}

.trend-item:hover { border-color: var(--border-strong); }

.trend-num {
  font-family: 'Noto Serif SC', serif;
  font-size: 36px;
  font-weight: 700;
  color: var(--border);
  line-height: 1;
  text-align: center;
  padding-top: 2px;
}

.trend-content-title {
  font-size: 14px;
  font-weight: 500;
  color: var(--ink);
  margin-bottom: 0.4rem;
}

.trend-content-desc {
  font-size: 13px;
  color: var(--ink-light);
  line-height: 1.7;
}

/* ════════════════════════════════════
   前言/引言块 Foreword
   用法：<div class="foreword">
     <p>称谓行</p>
     <p>正文段落...</p>
   </div>
   ════════════════════════════════════ */
.foreword {
  padding: 3rem;
  background: var(--parchment-deep);
  border: 0.5px solid var(--border);
  margin: 2rem 0;
  position: relative;
}

.foreword::before {
  content: '❝';
  font-family: 'Noto Serif SC', serif;
  font-size: 64px;
  color: var(--gold-pale);
  position: absolute;
  top: 16px;
  left: 20px;
  line-height: 1;
}

.foreword p {
  font-family: 'Noto Serif SC', serif;
  font-size: 14.5px;
  color: var(--ink-mid);
  line-height: 2;
  text-indent: 2em;
}

.foreword p:first-child {
  text-indent: 0;
  font-weight: 600;
  font-size: 15px;
}

/* ════════════════════════════════════
   合作机构横幅 Partners Bar
   用法：<div class="partners-bar">
     <div class="partner-item">
       <div class="partner-role">角色</div>
       <div class="partner-name">机构名称</div>
     </div>
   </div>
   ════════════════════════════════════ */
.partners-bar {
  display: flex;
  justify-content: center;
  gap: 0;
  margin: 2rem 0;
  border: 0.5px solid var(--border-strong);
  overflow: hidden;
}

.partner-item {
  flex: 1;
  text-align: center;
  padding: 1rem;
  border-right: 0.5px solid var(--border-strong);
  background: var(--parchment-deep);
}

.partner-item:last-child { border-right: none; }

.partner-role {
  font-size: 10px;
  letter-spacing: 0.1em;
  color: var(--gold);
  text-transform: uppercase;
  margin-bottom: 4px;
}

.partner-name {
  font-size: 12.5px;
  font-weight: 500;
  color: var(--ink-mid);
}

/* ════════════════════════════════════
   页脚 Footer
   用法：<footer>
     <div class="footer-inner">
       <div>
         <div class="footer-col-title">栏目标题</div>
         <p class="footer-text">内容</p>
       </div>
     </div>
     <div class="footer-bottom">
       <span>版权信息</span>
       <span>日期</span>
     </div>
   </footer>
   ════════════════════════════════════ */
footer {
  margin-top: 5rem;
  padding: 3rem 2rem;
  border-top: 1px solid var(--border-strong);
  background: var(--parchment-deep);
}

.footer-inner {
  max-width: 900px;
  margin: 0 auto;
  display: grid;
  grid-template-columns: 1fr 1fr 1fr;
  gap: 2rem;
}

.footer-col-title {
  font-size: 11px;
  letter-spacing: 0.1em;
  color: var(--gold);
  text-transform: uppercase;
  font-weight: 500;
  margin-bottom: 0.75rem;
}

.footer-text {
  font-size: 12px;
  color: var(--ink-light);
  line-height: 1.7;
}

.footer-bottom {
  max-width: 900px;
  margin: 2rem auto 0;
  padding-top: 1.5rem;
  border-top: 0.5px solid var(--border);
  display: flex;
  justify-content: space-between;
  align-items: center;
  font-size: 11px;
  color: var(--ink-muted);
  letter-spacing: 0.03em;
}

/* ════════════════════════════════════
   阅读进度条 Reading Progress
   用法：<div class="reading-progress" id="progress"></div>
   JS：window.addEventListener('scroll', () => {
     const pct = scrollTop / (scrollHeight - clientHeight) * 100;
     document.getElementById('progress').style.width = pct + '%';
   });
   ════════════════════════════════════ */
.reading-progress {
  position: fixed;
  top: 56px;
  left: 0;
  width: 0%;
  height: 2px;
  background: var(--gold);
  z-index: 99;
  transition: width 0.1s linear;
}

/* ════════════════════════════════════
   返回顶部按钮 Back to Top
   用法：<a href="#" class="back-top" id="backTop">↑</a>
   JS：控制 .visible 类的添加/移除
   ════════════════════════════════════ */
.back-top {
  position: fixed;
  bottom: 2rem;
  right: 2rem;
  width: 40px; height: 40px;
  background: var(--parchment-deep);
  border: 0.5px solid var(--border-strong);
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 16px;
  color: var(--gold);
  cursor: pointer;
  text-decoration: none;
  opacity: 0;
  transform: translateY(8px);
  transition: opacity 0.3s, transform 0.3s;
}

.back-top.visible {
  opacity: 1;
  transform: translateY(0);
}

/* ════════════════════════════════════
   响应式 Responsive
   ════════════════════════════════════ */
@media (max-width: 640px) {
  .toc-grid { grid-template-columns: 1fr; }
  .stats-banner { grid-template-columns: 1fr; }
  .footer-inner { grid-template-columns: 1fr; }
  .nav-links { display: none; }
  .partners-bar { flex-direction: column; }
  .partner-item { border-right: none; border-bottom: 0.5px solid var(--border-strong); }
  .partner-item:last-child { border-bottom: none; }
}

@media print {
  nav, .reading-progress, .back-top { display: none; }
  body { background: white; }
  .hero { padding-top: 2rem; }
}
