/* 基础变量与重置 */
:root{
  --bg: #fff;
  --text: #111;
  --muted: #666;
  --accent: #a80000; /* 克制朱红 */
  --rule: #e9e9e9;
  --masthead-width: 220px;
  --max-site-width: 1280px; /* 保持在1120-1440范围内（在桌面媒体生效） */
  --gap: 28px;
  --sans: -apple-system, BlinkMacSystemFont, "Helvetica Neue", "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", Arial, sans-serif;
}
*{box-sizing:border-box}
html,body{height:100%;margin:0;background:var(--bg);color:var(--text);font-family:var(--sans);-webkit-font-smoothing:antialiased;-moz-osx-font-smoothing:grayscale}
a{color:inherit;text-decoration:none}
.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}

/* 整体布局 */
.site-outer{display:flex;flex-direction:column;min-height:100vh}
.masthead{background:transparent;color:var(--text);padding:18px 16px;border-right:0;width:100%}
.masthead-top{display:flex;flex-direction:column;align-items:stretch}
.masthead-nav{display:flex;align-items:center;justify-content:center;gap:12px;font-weight:600}
.masthead-nav .site-link{font-size:1rem}
.masthead-nav .nav-left,.masthead-nav .nav-right{font-size:0.95rem;color:var(--muted)}
.masthead-body{padding:16px 0}
.masthead-label{font-size:0.9rem;color:var(--muted);letter-spacing:0.02em}
.masthead-rule{border:0;border-top:1px solid var(--rule);margin:10px 0}
.ad{font-size:0.9rem;color:var(--muted);padding:6px 0}

.site-inner{width:100%;margin:0 auto;padding:24px;flex:1}
.article{max-width:100%;margin:0 auto}
.article-header{display:flex;flex-wrap:wrap;align-items:flex-start;gap:18px;margin-bottom:18px}
.title-wrap{flex:1 1 60%;min-width:280px}
.article-title{margin:0;font-size:28px;line-height:1.15;font-weight:700;word-break:break-word}
/* 视觉识别：标题首字强调 */
.article-title::first-letter{color:var(--accent);font-weight:900}
.meta{margin-top:8px;color:var(--muted);font-size:0.9rem}
.summary{flex:0 0 320px;color:var(--muted);font-size:0.98rem}

/* 内容与边注网格 */
.article-grid{display:block}
.article-body{min-width:0}
.content{margin-top:6px}
.content p{line-height:1.85;margin:0 0 1em;color:var(--text)}
.side-note{margin-top:18px;border-top:1px solid var(--rule);padding-top:12px}
.side-title{margin:0;font-weight:700;color:var(--muted)}
.side-desc{margin:6px 0 0;color:var(--muted);font-size:0.95rem}

.section-title{font-size:1.05rem;margin:20px 0 10px;color:var(--text);font-weight:700}
.faq-list{border-top:1px solid var(--rule);padding-top:12px}
.faq-list > * + *{border-top:1px solid var(--rule);padding-top:12px;margin-top:12px}
.related-list{display:grid;grid-template-columns:repeat(3,1fr);gap:12px}
.related-list > *{padding:10px;background:transparent;border:0;border-left:3px solid transparent}
.related-list > *:hover{border-left-color:var(--accent)}

.site-footer{padding:18px 24px;border-top:1px solid var(--rule);font-size:0.95rem;color:var(--muted)}

/* 手机端: 320px - 767px */
@media (max-width:767px){
  :root{--gap:18px}
  .masthead{display:block;padding:12px}
  .masthead-nav{justify-content:center;gap:8px}
  .masthead-body{padding:8px 0}
  .masthead-label{display:none}
  .masthead{border-right:0}
  .site-inner{padding:16px}
  .article-header{flex-direction:column;align-items:stretch}
  .title-wrap{order:1}
  .article-title{font-size:22px}
  .summary{order:2;flex:1 1 auto;width:100%;margin-top:8px}
  .article-grid{display:block}
  .side-note{order:4;border-top:1px solid var(--rule);padding-top:12px}
  .ad{padding:10px 0}
  .related-list{grid-template-columns:1fr;gap:10px}
  /* 避免横向滚动 */
  body,html{overflow-x:hidden}
}

/* 桌面端: >=1024px，精确实现纵向刊头与9/3网格 */
@media (min-width:1024px){
  .site-inner{display:grid;grid-template-columns:var(--masthead-width) 1fr;gap:var(--gap);align-items:start;max-width:var(--max-site-width);padding:32px;min-width:1120px}
  .masthead{position:static;width:var(--masthead-width);padding:28px 18px}
  /* 将 masthead 放在左侧：通过 grid 布局，header 放置在左列 */
  header.masthead{grid-column:1 / 2;grid-row:1}
  main.site-inner > article{grid-column:2 / 3}
  .article-header{display:grid;grid-template-columns:1fr 320px;grid-column:1 / -1;align-items:start;gap:20px}
  /* 标题跨主区（跨越内容与边注之上） */
  .article-grid{display:grid;grid-template-columns:9fr 3fr;gap:28px;margin-top:6px}
  .article-body{grid-column:1 / 2}
  .side-note{grid-column:2 / 3;border-top:0;padding-top:0}
  .article-title{font-size:32px}
  .summary{align-self:start}
  .related-list{grid-template-columns:repeat(3,1fr)}
}

/* 可访问性与阅读舒适度 */
.content img{max-width:100%;height:auto}
.content pre, .content code{font-family:monospace;font-size:0.95rem;background:transparent;padding:6px;border-radius:2px}

/* 禁止阴影类样式以符合 forbidden_pattern */
*{box-shadow:none}