/* Core variables and reset */
:root{
  --bg:#ffffff;
  --ink:#111111;
  --muted:#666666;
  --accent:#c30b0b; /* 朱红 */
  --header-bg:#0f0f0f; /* 深色报头 */
  --max-width-clamp: clamp(1120px, 80vw, 1360px);
  --gap:24px;
  --base-line:20px; /* baseline grid */
  --sub-line:10px;  /* secondary baseline */
  --surface-border: #e6e6e6;
  --radius:2px; /* square small rounding */
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial, "Noto Sans", "PingFang SC", "Hiragino Sans GB", sans-serif;
  color-scheme: light;
}
*{box-sizing:border-box}
html,body{height:100%;background:var(--bg);color:var(--ink);margin:0}
img,svg,video{max-width:100%;height:auto}
a{color:var(--accent);text-decoration:none}
ul{margin:0;padding:0;list-style:none}
/* Header: narrow, dark */
.site-header{background:var(--header-bg);color:#fff}
.header-inner{max-width:var(--max-width-clamp);margin:0 auto;padding:12px 20px;display:flex;align-items:center;justify-content:space-between}
.site-name{font-weight:700;color:#fff;text-decoration:none}
.site-nav ul{display:flex;gap:18px;font-size:14px;color:#ddd}
.site-nav li{opacity:.95}
/* Page wrapper and container */
.page-wrapper{padding:24px 12px}
.container{max-width:var(--max-width-clamp);margin:0 auto}
/* Article grid: sets base layout but desktop rules override */
.article-grid{display:block}
.article-head h1{margin:18px 0 6px;font-size:28px;line-height:1.08;font-weight:700;color:var(--ink);max-height:calc(1.08 * 2 * 28px);overflow:visible}
.meta-row{display:flex;gap:12px;font-size:13px;color:var(--muted);align-items:center;margin-bottom:10px}
.summary{margin:8px 0 18px;color:var(--muted);line-height:1.6}
/* Main column and side note default stacking for mobile */
.main-col{width:100%}
.content{background:var(--bg);padding:18px;border:1px solid var(--surface-border);border-radius:var(--radius);line-height:1.9;color:var(--ink);font-size:16px}
/* Visual signature: double baseline grid in content area */
.content{
  background-image:
    repeating-linear-gradient(transparent, transparent calc(var(--sub-line) - 1px), rgba(0,0,0,0.02) calc(var(--sub-line) - 1px), rgba(0,0,0,0.02) var(--sub-line)),
    repeating-linear-gradient(transparent, transparent calc(var(--base-line) - 1px), rgba(0,0,0,0.03) calc(var(--base-line) - 1px), rgba(0,0,0,0.03) var(--base-line));
  background-size: auto;
  background-repeat:repeat-y;
  background-attachment: local;
}
/* Surface square info blocks for aside */
.side-note{margin-top:18px}
.note-surface{background:#fff;border:1px solid var(--surface-border);padding:14px}
.note-surface h3{margin:0 0 8px;font-size:15px}
.note-item{padding:8px 0;border-top:1px solid var(--surface-border);font-size:13px}
.note-item:first-of-type{border-top:0;padding-top:0}
.muted{color:var(--muted)}
/* Sections */
.section-title{font-size:15px;margin:20px 0 10px;color:var(--ink);border-left:3px solid var(--accent);padding-left:10px}
.faq-block .faq-list ol{padding-left:20px;margin:0}
.faq-block .faq-list li{margin:10px 0;line-height:1.6}
.related-list{display:block}
.related-list > * + *{border-top:1px solid var(--surface-border);padding-top:10px;margin-top:10px}
.related-list a{display:flex;justify-content:space-between;align-items:center;color:var(--ink);padding:6px 0}
.related-list time{color:var(--muted);font-size:13px}
/* Ad slots are independent containers, non-floating */
.ad-slot{margin:18px 0;padding:12px;border:1px dashed var(--surface-border);background:#fff;color:var(--muted);font-size:14px}
/* Footer */
.site-footer{border-top:1px solid var(--surface-border);padding:18px 0;margin-top:30px}
.footer-inner{max-width:var(--max-width-clamp);margin:0 auto;padding:0 20px;color:var(--muted);font-size:13px}
/* Desktop specific layout: 10/2 asymmetric grid */
@media (min-width:1024px){
  .page-wrapper{padding:40px 20px}
  .article-grid{display:grid;grid-template-columns:repeat(12,1fr);column-gap:28px;align-items:start;row-gap:20px}
  .article-head{grid-column:1 / -1;padding:8px 0}
  .main-col{grid-column:1 / span 10}
  .side-note{grid-column:11 / span 2}
  .side-note{position:relative;top:6px}
  .article-head h1{font-size:44px;line-height:1.02;margin:6px 0 10px;max-height: calc(44px * 2 * 1.02)}
  .summary{font-size:16px}
  .content{font-size:17px;padding:22px}
  .note-surface{border-radius:0}
  /* ensure content column is spacious and not narrow like phone */
  .container{padding:0}
}
/* Mobile layout rules: independent reflow, side-note moves below title */
@media (max-width:767px){
  :root{--base-line:18px;--sub-line:9px}
  .header-inner{padding:10px 14px}
  .site-nav ul{gap:12px;font-size:13px}
  .page-wrapper{padding:12px}
  .article-head h1{font-size:20px;line-height:1.06;margin:8px 0}
  .meta-row{flex-direction:row;gap:8px;font-size:12px}
  .summary{font-size:14px}
  .content{padding:14px;font-size:15px}
  .article-grid{display:block}
  .side-note{margin-top:12px}
  .note-surface{padding:12px}
  .section-title{margin-top:16px}
  .ad-slot{margin:14px 0}
  /* ensure no horizontal scroll at 320px */
  .container{padding:0 10px}
}
/* Accessibility and focus */
a:focus, button:focus{outline:2px solid var(--accent);outline-offset:3px}