:root{
  --ink: #083826; /* 墨绿 */
  --paper: #f6f3ea; /* 米白 */
  --muted: #6b6b6b;
  --line: #e6e3da;
  --max-page: 1280px;
  --content-width: 860px; /* 正文宽度 */
  --title-width: 980px; /* 标题区宽度（与正文不同） */
  --gap: 24px;
  --radius: 4px;
  --font-sans: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial, "Noto Sans", "PingFang SC", "Hiragino Sans GB", "Microsoft Yahei", sans-serif;
}

*{box-sizing:border-box}
html,body{height:100%;margin:0;background:var(--paper);color:var(--ink);font-family:var(--font-sans);-webkit-font-smoothing:antialiased}
a{color:inherit;text-decoration:none}
.page{margin:24px auto;padding:0 20px}

/* Header */
.site-header{background:transparent;padding:12px 0 8px;border-bottom:1px solid var(--line)}
.header-top{display:flex;align-items:center;justify-content:space-between;gap:12px;max-width:var(--max-page);margin:0 auto;padding:0 20px}
.brand{font-weight:700;color:var(--ink)}
.col-index{display:flex;gap:14px;font-size:14px;color:var(--muted)}
.col-index .col{padding:4px 6px}
.header-slim{height:6px;background:transparent;max-width:var(--max-page);margin:8px auto 0}

/* Title area */
.title-area{max-width:var(--max-page);margin:18px auto;padding:0 20px}
.title-wrap{width:var(--title-width);max-width:100%}
.page-title{font-size:28px;line-height:1.25;margin:0 0 12px 0;font-weight:700;text-align:left}
.title-lines{height:4px;border-top:3px solid var(--ink);border-bottom:1px solid var(--line);width:42%;margin-top:-6px}

/* Article */
.content-area{max-width:var(--max-page);margin:0 auto;padding:20px;background:transparent}
.content-area .meta{font-size:13px;color:var(--muted);margin-bottom:12px}
.summary{background:#fff;border:1px solid var(--line);padding:14px;border-radius:var(--radius);margin-bottom:18px}
.summary-label{display:block;color:var(--ink);font-weight:600;margin-bottom:6px}
.desc{margin:0;color:var(--muted)}

.body{background:#fff;border:1px solid var(--line);padding:26px;border-radius:var(--radius);line-height:1.75;color:#222}
.body-inner{max-width:var(--content-width);margin:0 auto}
.body p{margin:0 0 12px}

/* Ad slots (non-floating) */
.ad-slot{max-width:var(--max-page);margin:18px auto;padding:12px;border:1px dashed var(--line);background:transparent;color:var(--muted);text-align:center;font-size:13px}
.ad-top{margin-top:8px}

/* FAQ - left question, right answer on desktop */
.faq{margin-top:22px}
.faq .section-title{font-size:16px;margin:0 0 12px;color:var(--ink)}
.faq-list{background:#fff;border:1px solid var(--line);padding:12px;border-radius:var(--radius)}
.faq-list > *{padding:10px 0;border-bottom:1px solid var(--line);display:flex;gap:12px}
.faq-list > *:last-child{border-bottom:none}
.faq-question{flex:0 0 32%;color:var(--ink);font-weight:600}
.faq-answer{flex:1;color:#333}

/* Related - keyword index style */
.related{margin-top:22px}
.related .section-title{font-size:16px;margin:0 0 12px;color:var(--ink)}
.related-list{background:#fff;border:1px solid var(--line);padding:14px;border-radius:var(--radius)}
.related-list ul{list-style:none;padding:0;margin:0;display:grid;grid-template-columns:repeat(3,1fr);gap:8px}
.related-list li{padding:6px 8px;border:1px solid var(--line);background:transparent;font-size:14px;color:var(--ink);word-break:break-word}
.related-list a{color:var(--ink)}

/* Footer */
.site-footer{max-width:var(--max-page);margin:26px auto;padding:12px 20px;text-align:center;color:var(--muted)}

/* Desktop specific rules */
@media (min-width:1024px){
  .page{width:1200px;min-width:1120px;max-width:1440px;padding:0}
  .header-top{padding:0}
  .title-wrap{width:var(--title-width)}
  .page-title{font-size:34px}
  .content-area{padding:28px}
  .summary{padding:18px}
  .body{padding:32px}
  .body-inner{width:var(--content-width)}
  /* Ensure distinct desktop structure: title area wider than content, content centered at ~860px */
  .title-area{display:flex;justify-content:flex-start}
  .title-wrap{margin-left:0}
  /* FAQ table-like: left question right answer enforced above */
  .faq-list > *{align-items:flex-start}
  /* Related three-column grid enforced */
  .related-list ul{grid-template-columns:repeat(3,1fr)}
}

/* Mobile specific rules */
@media (max-width:767px){
  :root{--content-width:100%}
  .page{margin:0;padding:0 12px}
  .header-top{padding:10px 0;flex-direction:row;align-items:center}
  .col-index{display:none} /* 简化移动导航 */
  .header-slim{height:4px}
  .title-wrap{width:100%}
  .page-title{font-size:20px}
  .title-lines{width:36%}
  .content-area{padding:12px}
  .summary{margin-bottom:12px}
  .body{padding:16px}
  .body-inner{width:100%}
  .ad-slot{margin:14px 0}
  /* FAQ stacked on mobile */
  .faq-list > *{display:block;padding:10px 0}
  .faq-question{display:block;margin-bottom:6px;flex:auto}
  .faq-answer{display:block}
  /* Related becomes single column list */
  .related-list ul{grid-template-columns:1fr}
  .related-list li{font-size:15px}
  .site-footer{padding:16px}
  /* Ensure no horizontal scroll on narrow screens */
  html,body{overflow-x:hidden}
}

/* Accessibility and density */
.page-title, .section-title{letter-spacing:0.2px}
.summary, .body, .faq-list, .related-list{line-height:1.6}

/* Visual signature: large whitespace with compact typographic scale enforced via margins and measured widths */