/* Palette & base */
:root{
  --bg:#f6f7f5; /* 轻纸张底色 */
  --ink:#182026;
  --muted:#5b6b6b;
  --accent:#4aa6c7; /* 湖蓝 */
  --accent-deep:#2f8ea6; /* 青灰偏深 */
  --sig-reverse:#183f47; /* 相关推荐反向色块 */
  --page-min:1120px;
  --page-max:1440px;
  --content-width:860px; /* 正文宽度约860px */
  --gap:22px;
  --font-sans:-apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, 'Helvetica Neue', Arial, 'Noto Sans SC', 'PingFang SC', 'Hiragino Sans GB', 'Microsoft YaHei', sans-serif;
}

*{box-sizing:border-box}
html,body{height:100%}
body{
  margin:0;
  font-family:var(--font-sans);
  background:var(--bg);
  color:var(--ink);
  line-height:1.65;
  -webkit-font-smoothing:antialiased;
}

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

/* Header: 报刊双层报头（两行） */
.site-header{padding:18px 0 8px;border-bottom:1px solid rgba(24,32,38,0.06)}
.header-row{display:flex;align-items:center;justify-content:space-between;padding:6px 20px}
.header-top{font-size:13px;color:var(--muted)}
.header-top .header-center{flex:0 0 auto;text-align:center;font-weight:700}
.header-top .home-link{font-size:16px;letter-spacing:0.02em}
.header-band{font-size:12px;color:var(--muted);border-top:1px solid rgba(24,32,38,0.04);padding-top:8px}
.header-band .band-left{font-weight:600}
.header-band .band-issue{opacity:0.85}

/* Page wrapper and width constraints
   Desktop contract: page container between 1120px—1440px
*/
.page-wrapper{padding:18px 12px 40px}
.page-width{margin:0 auto;width:100%;max-width:1280px}

/* Article head & title composition
   标题压左并用粗细横线构图
*/
.article-head{margin:18px 12px 10px}
.title-band{display:block;padding:6px 0 12px}
.title-band h1{margin:0;padding:0;font-size:28px;font-weight:800;letter-spacing:-0.01em;text-align:left;color:var(--ink)}
.title-decor{display:flex;align-items:center;gap:10px;margin-top:10px}
.title-decor .thick-line{display:inline-block;height:6px;width:48px;background:var(--accent-deep);border-radius:2px}
.title-decor .thin-line{display:inline-block;height:2px;width:220px;background:linear-gradient(90deg,var(--accent) 0%,rgba(74,166,199,0.5) 100%);opacity:0.9}

.meta{display:flex;flex-wrap:wrap;align-items:center;gap:8px;font-size:13px;color:var(--muted);margin-top:12px}
.meta .keywords{margin-left:6px;color:var(--muted)}
.description{margin:14px 0 18px;color:var(--muted);max-width:100%}

/* Content: 正文居中、宽度约860px */
.content{background:transparent;max-width:var(--content-width);margin:0 auto;padding:0 6px}
.content :where(p,ul,ol,blockquote){color:var(--ink);margin:0 0 1em}

/* FAQ pattern: 主题色顶部边线问答区 */
.faq{max-width:var(--content-width);margin:26px auto 14px;padding:12px 6px;border-top:4px solid var(--accent);}
.faq h2{margin:0 0 10px;font-size:16px;color:var(--accent-deep)}
.faq-body{color:var(--muted)}

/* Related: 反向色块标题栏 + 编号列表 */
.related{max-width:var(--content-width);margin:18px auto;padding:0}
.related h2{margin:0 0 8px;padding:10px 12px;background:var(--sig-reverse);color:#fff;font-size:15px}
.related-body{padding:10px 12px}
.related-body ol{margin:0;padding-left:20px}
.related-body ol li{margin:8px 0;color:var(--muted)}

/* Ad containers: independent, not floating */
.ad-slot{max-width:var(--content-width);margin:20px auto;padding:8px 12px;color:var(--muted);font-size:13px;border-radius:4px;background:transparent}
.ad-slot > *{display:block}

/* Footer */
.site-footer{border-top:1px solid rgba(24,32,38,0.06);padding:18px 12px;text-align:center;color:var(--muted);font-size:13px}

/* Desktop specific rules (>=1024px) distinct layout
   - page container between 1120px—1440px
   - title area and正文使用不同宽度，正文约860px居中
   - 无侧栏宽屏阅读
   - 相关推荐底部三列展开
*/
@media (min-width:1024px){
  .page-width{width:1200px;min-width:var(--page-min);max-width:var(--page-max);padding:0 20px}
  .title-band h1{font-size:36px}
  .title-decor .thin-line{width:360px}
  .article-head{padding:12px 6px 18px}
  .content{padding:0}
  .faq{padding:18px}
  .related-body{display:grid;grid-template-columns:repeat(3,1fr);gap:14px;padding:14px}
  .related-body > *{background:rgba(24,32,38,0.03);padding:10px;border-radius:2px}
  .related-body ol{padding-left:18px}
  .ad-slot{padding:12px}
}

/* Mobile specific rules (<=767px)
   - 正文全宽减安全边距
   - 底部三列变单列
   - 防止横向滚动、文字截断或控件重叠
*/
@media (max-width:767px){
  .page-wrapper{padding:12px 14px 30px}
  .page-width{max-width:100%;padding:0}
  .header-row{padding:6px 8px}
  .title-band h1{font-size:20px}
  .title-decor .thin-line{display:none}
  .title-decor .thick-line{width:34px;height:5px}
  .article-head{margin-bottom:10px}
  .description{font-size:14px}
  .content{max-width:100%;margin:0;padding:0 2px}
  .faq,.related,.ad-slot{max-width:100%;margin-left:0;margin-right:0;padding-left:0;padding-right:0}
  .faq{border-top-width:3px;padding:10px}
  .related-body{display:block;padding:8px}
  .related-body > *{margin-bottom:10px}
  .related-body ol{padding-left:18px}
  .ad-slot{padding:10px}
  .site-footer{padding:14px}
}

/* Accessibility & density
   - 舒展的行距与空白（density: 舒展）
*/
h1,h2,h3{line-height:1.15}
p,li{line-height:1.8}

/* Visual signature & forbidden pattern enforcement note (CSS-level):
   - no right-side热门文章 layout is created; layout stays single-column centered article on desktop
*/