/* Palette and variables */
:root{
  --bg: #fff6eb; /* 奶油白 */
  --brand: #3b2b23; /* 深棕 */
  --muted: #7a6b63;
  --line: rgba(59,43,35,0.12);
  --max-width-1: 1320px;
  --max-width-2: 1200px;
  --gap: 20px;
  --font-sans: -apple-system,BlinkMacSystemFont,Segoe UI,Roboto,Helvetica,Arial,'Microsoft YaHei','PingFang SC',sans-serif;
}

/* Basic reset */
*{box-sizing:border-box}
html,body{height:100%}
body{
  margin:0;
  font-family:var(--font-sans);
  background:var(--bg);
  color:var(--brand);
  -webkit-font-smoothing:antialiased;
  -moz-osx-font-smoothing:grayscale;
  line-height:1.45;
  font-size:15px; /* 紧凑 */
}
.container{margin:0 auto;padding:0 var(--gap)}
.container.narrow{max-width:1100px}

/* Header: 双层报头但第二层极窄 */
.topbar{border-bottom:1px solid var(--line);background:transparent}
.topbar .container{display:flex;align-items:center;justify-content:space-between;padding:10px 16px}
.brand a{color:var(--brand);text-decoration:none;font-weight:700}

.masthead{border-bottom:1px solid var(--line);}
.masthead .container{display:flex;align-items:center;justify-content:space-between;padding:18px 16px}
.logo-text{margin:0;font-size:18px;color:var(--brand);font-weight:700}
.main-nav ul{display:flex;gap:18px;list-style:none;margin:0;padding:0}
.main-nav a, .main-nav span{color:var(--muted);text-decoration:none;font-size:14px}

.nav-slim{border-top:1px solid var(--line);border-bottom:1px solid var(--line);}
.nav-slim .container{padding:6px 16px}
.category-strip{overflow:auto}
.category-strip ul{display:flex;gap:12px;list-style:none;margin:0;padding:0}
.category-strip span{display:inline-block;padding:6px 12px;min-height:44px;line-height:44px;color:var(--brand);font-size:13px}

.ad-top{padding:12px 16px;border-bottom:1px solid var(--line)}

/* Page layout grid */
.page-wrap{padding:18px 0}
.page-container{margin:0 auto}
.content-grid{display:block}

/* Article */
.article{background:transparent}
.article-header h1{margin:0 0 8px 0;font-size:26px;line-height:1.18;color:var(--brand);font-weight:700;display:block;border-left:4px solid var(--brand);padding-left:12px}
.article-header .meta{display:flex;gap:12px;color:var(--muted);font-size:13px;margin-top:8px}
.summary{margin-top:14px;color:var(--muted);font-size:14px;padding:12px 0;border-top:1px solid var(--line);}

.article-body{margin-top:18px;color:var(--brand);font-size:15px;line-height:1.6}
.article-body p{margin:0 0 12px}

.ad-middle{margin:18px 0;padding:12px;border-top:1px solid var(--line);border-bottom:1px solid var(--line)}

.faq{margin-top:18px;border-top:1px solid var(--line);padding-top:12px}
.faq h3{margin:0 0 8px 0;font-size:16px}
.faq-inner{color:var(--brand);font-size:14px}
.faq-inner ol{padding-left:20px}

.related{margin-top:18px;border-top:1px solid var(--line);padding-top:12px}
.related h3{margin:0 0 8px 0}
.related-grid{display:grid;grid-template-columns:repeat(4,1fr);gap:10px;font-size:13px}
.related-grid a{color:var(--brand);text-decoration:none}

/* Sidebar */
.sidebar{margin-top:18px;padding-left:22px}
.sidebar .vline{position:absolute;left:0;top:0;width:1px;background:var(--brand);opacity:0.08;height:100%}
.sidebar-block{border:1px solid var(--line);padding:12px 10px;margin-bottom:12px}
.sidebar-block h4{margin:0 0 8px 0;font-size:13px;color:var(--brand)}
.keywords{color:var(--muted);font-size:13px}
.small-meta ul{margin:0;padding-left:18px;color:var(--muted);font-size:13px}

/* Footer */
.site-footer{border-top:1px solid var(--line);padding:14px 0;margin-top:30px}
.site-footer small{color:var(--muted)}

/* Visual signature: 1px 竖线贯穿页面 */
body:before{content:"";position:fixed;left:60px;top:0;height:100vh;width:1px;background:var(--brand);opacity:0.06;pointer-events:none}

/* Desktop layout - distinct structure */
@media (min-width:1024px){
  .page-container{margin:0 auto;display:block;padding:0 20px}
  /* Ensure container width grows on larger screens; for wide screens keep within expected band */
  @supports (width:clamp(1px,1px,1px)){}
}

@media (min-width:1280px){
  .page-container{max-width:var(--max-width-2);}
  .content-grid{display:grid;grid-template-columns:1fr 300px;gap:28px;align-items:start}
  .sidebar{position:relative;padding-left:28px}
  .article-header h1{font-size:30px}
  .article-body{font-size:16px}
}

@media (min-width:1440px){
  .page-container{max-width:var(--max-width-1)}
  .content-grid{grid-template-columns:1fr 320px}
}

/* Mobile layout - independent reflow, sidebar moves below, slim nav scroll */
@media (max-width:767px){
  .topbar .container{padding:8px 12px}
  .masthead .container{padding:12px}
  .nav-slim .container{padding:6px 8px}
  .category-strip ul{gap:8px}
  .page-container{padding:0 12px}
  .content-grid{display:block}
  .article-header h1{font-size:20px;padding-left:8px;border-left:3px solid var(--brand)}
  .article-header .meta{flex-direction:column;gap:6px}
  .summary{padding:10px 0}
  .article-body{font-size:15px}
  .sidebar{padding:0;margin-top:18px}
  .sidebar .vline{display:none}
  .related-grid{grid-template-columns:repeat(2,1fr);gap:8px}
  .category-strip span{min-height:44px;padding:6px 14px}
  /* Ensure tappable areas >=44px */
  .main-nav a, .main-nav span{padding:10px 6px;display:inline-block}
}

/* Accessibility & low visual noise */
a{color:var(--brand)}
a:focus{outline:2px dashed rgba(59,43,35,0.18);outline-offset:2px}

/* Avoid rounded corners and heavy shadows */
*{border-radius:0}