/* Theme variables */
:root{
  --bg:#ffffff;
  --surface:#ffffff;
  --ink:#111213; /* 炭黑 */
  --muted:#7a7a78; /* 暖灰 */
  --accent:#b45a3a; /* 克制的强调色（暖） */
  --rail-bg:#f5f2f0; /* 暖灰背景用于侧栏方形块 */
  --max-desktop:1440px;
  --min-desktop:1120px;
  --container-pad:28px;
  --line-height:1.75;
}

/* Basic reset */
*{box-sizing:border-box}
html,body{height:100%;margin:0;font-family: -apple-system,BlinkMacSystemFont,"Segoe UI",Roboto,"Helvetica Neue",Arial,"Noto Sans",sans-serif;color:var(--ink);background:var(--bg);}
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);border:0}

/* Header */
.site-header{background:#1b1b1b;color:#fff}
.header-top{display:flex;align-items:center;justify-content:space-between;max-width:1200px;margin:0 auto;padding:12px var(--container-pad)}
.brand{font-weight:700;font-size:1rem;color:#fff}
.nav-primary{font-size:0.95rem;opacity:0.9}
.nav-item{margin:0 6px;color:#e9e7e6}
.nav-sep{color:#3a3a3a;margin:0 6px}
.header-slim{background:#111;padding:6px var(--container-pad);border-top:1px solid rgba(255,255,255,0.03)}
.nav-slim{font-size:0.85rem;color:#cfc9c6;display:flex;gap:12px;max-width:1200px;margin:0 auto}

/* Page container */
.page-wrap{padding:20px 0}
.layout-grid{display:grid;gap:20px;max-width:100%;margin:0 auto;padding:0 var(--container-pad)}

/* Left rail boxes: square, flat, no large radii */
.rail-left{display:flex;flex-direction:column;gap:12px}
.rail-box{background:var(--rail-bg);padding:12px;box-shadow:none;border:1px solid rgba(0,0,0,0.04)}
.rail-brand{font-weight:700;font-size:1rem}
.rail-heading{margin:0 0 8px 0;font-size:0.95rem}
.related-list{counter-reset:related}
.related-list > *{display:block}
.related-list li{counter-increment:related;margin:6px 0;list-style:none;padding-left:20px;position:relative}
.related-list li::before{content:counter(related)".";position:absolute;left:0;color:var(--muted);font-weight:600}

.meta-snapshot .meta-row{font-size:0.92rem;color:var(--ink);margin-bottom:6px}
.meta-snapshot .muted{color:var(--muted);font-size:0.88rem}

/* Article */
.content-right{background:var(--surface);padding:18px;border:1px solid rgba(0,0,0,0.04)}
.eyebrow.compact{font-size:0.85rem;color:var(--muted);font-weight:600;margin-bottom:8px}
.article-header{margin-bottom:12px}
.article-title{font-family:Georgia, 'Times New Roman', Times, serif;font-size:1.9rem;line-height:1.15;margin:0;color:var(--ink)}
.article-title::first-letter{color:var(--accent);font-size:2.4rem;font-weight:700}
.article-meta{margin-top:8px;color:var(--muted);font-size:0.9rem}
.article-meta .sep{margin:0 8px;color:var(--muted)}
.summary p{margin:12px 0 0 0;color:var(--muted);line-height:1.6}

.article-body{margin-top:18px;color:var(--ink);font-size:1rem;line-height:var(--line-height)}
.article-body p{margin:0 0 1em}

/* FAQ pattern: theme color top border */
.faq{border-top:3px solid var(--accent);padding-top:12px;margin-top:18px}
.faq h3{margin:0 0 10px 0}
.faq-inner{color:var(--muted)}

/* Ad containers: independent, non-floating */
.ad-container{max-width:1200px;margin:18px auto;padding:12px;border:1px dashed rgba(0,0,0,0.06);background:transparent;text-align:center;font-size:0.95rem;color:var(--muted)}

/* Footer */
.site-footer{padding:18px var(--container-pad);font-size:0.9rem;color:var(--muted);text-align:center}

/* Desktop layout (>=1024px) - reverse rail: left 4 / right 8 */
@media (min-width:1024px){
  .layout-grid{display:grid;grid-template-columns:repeat(12,1fr);gap:28px;width:clamp(var(--min-desktop),90vw,var(--max-desktop));}
  .rail-left{grid-column:1/5}
  .content-right{grid-column:5/13}

  /* Left rail fixed visual density - square blocks */
  .rail-box{border-radius:2px;padding:16px}

  /* Increase title size on desktop */
  .article-title{font-size:2.4rem}
  .article-title::first-letter{font-size:3rem}

  /* Make related list dense but numbered */
  .related-list li{margin:8px 0}
}

/* Mobile layout (<=767px) - single column, left-rail content splits into compact blocks before/after title */
@media (max-width:767px){
  .layout-grid{display:flex;flex-direction:column;gap:12px;padding:0 14px}

  /* Reflow: bring some left rail elements near title by visual order - using duplication via order of containers */
  .rail-left{order:1;display:flex;flex-direction:row;gap:8px;flex-wrap:wrap}
  .rail-box{flex:1 1 auto;padding:10px}
  .brand-box{flex-basis:60%}
  .meta-snapshot{flex-basis:40%;font-size:0.85rem}

  /* Article becomes primary reading block */
  .content-right{order:2;padding:14px}
  .eyebrow.compact{display:block;margin-top:8px}

  /* Adjust title sizing for small screens */
  .article-title{font-size:1.5rem}
  .article-title::first-letter{font-size:1.8rem}

  .ad-container{margin:12px 0}

  /* Ensure no horizontal scroll */
  html,body{overflow-x:hidden}
}

/* Accessibility and density tweaks */
.article-body img{max-width:100%;height:auto}

/* Avoid forbidden patterns: no heavy shadows, no blur, no large radii */
*{transition:none}