:root{
  --bg:#f6f7f5; /* 轻纸张底色 */
  --ink:#1f2933; /* 深色文字 */
  --muted:#6b7280; /* 次要文案 */
  --accent:#4aa3c6; /* 湖蓝点缀 */
  --accent-2:#8aa6a2; /* 青灰 */
  --max-width:1320px; /* 在1120-1440区间选择 */
  --gap:22px;
  --sans: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial, "Noto Sans CJK SC", "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", sans-serif;
}

/* Reset & base */
*{box-sizing:border-box}
html,body{height:100%;background:var(--bg);color:var(--ink);font-family:var(--sans);margin:0}
a{color:inherit;text-decoration:none}

/* Header: 报刊双层报头 */
.site-header{padding:10px 18px 18px;border-bottom:1px solid rgba(31,41,51,0.06);background:linear-gradient(180deg, rgba(250,251,250,0) 0%, rgba(255,255,255,0.6) 100%)}
.header-top{display:flex;justify-content:space-between;font-size:13px;color:var(--muted);padding:2px 0}
.header-main{display:flex;align-items:center;justify-content:space-between;padding-top:6px}
.site-title{font-weight:700;font-size:18px;letter-spacing:0.02em;text-align:center}
.site-title a{color:var(--ink)}
.nav-left,.nav-right{color:var(--muted);font-size:14px}

/* Page container */
.page-wrap{display:flex;justify-content:center;padding:28px 16px 60px}
.page-grid{width:100%;max-width:var(--max-width);display:grid;grid-template-columns:1fr;gap:var(--gap)}

/* Left related (desktop only) */
.related-left{display:none}
.related-left .aside-title{font-size:15px;color:var(--accent-2);margin:0 0 12px}
.related-list{display:flex;flex-direction:column;gap:10px;color:var(--muted);font-size:14px}

/* Article styles */
.article{background:transparent;padding:0}
.article-header{margin-bottom:18px}
.title{font-weight:800;color:var(--ink);margin:0 0 8px;line-height:1.05;font-family:var(--sans);font-size:clamp(28px,4.4vw,44px)}
.meta{display:flex;gap:12px;font-size:13px;color:var(--muted);margin-bottom:12px}
.lead{margin:0;color:var(--muted);line-height:1.6}

.article-body{padding-top:6px}
.content-wrapper{display:block}
.content{color:var(--ink);line-height:1.8;white-space:normal}

/* FAQ: 横线问答列表 */
.faq-section{margin-top:24px}
.section-title{font-size:16px;color:var(--accent-2);margin:0 0 12px}
.faq-list{border-top:1px solid rgba(31,41,51,0.06)}
.faq-list > *{padding:12px 0;border-bottom:1px solid rgba(31,41,51,0.06);color:var(--muted)}

/* Ads: independent containers, no floating */
.ad{background:transparent;padding:12px 0;text-align:center;color:var(--muted);font-size:13px}

/* Related bottom (mobile three-column pattern) */
.related-bottom{display:none;margin-top:18px}
.related-grid{display:grid;grid-template-columns:repeat(3,1fr);gap:10px;font-size:14px;color:var(--muted)}
.related-grid > *{padding:8px;border-radius:4px;border:1px solid rgba(31,41,51,0.04);background:transparent}

/* Footer */
.site-footer{border-top:1px solid rgba(31,41,51,0.06);padding:18px 16px;text-align:center;color:var(--muted);font-size:13px}

/* VISUAL SIGNATURE: 大面积留白配紧凑字阶 */
/* 使用留白与紧凑标题层级来形成识别 */

/* Desktop layout (min-width:1024px) - required */
@media (min-width:1024px){
  .page-grid{display:grid;grid-template-columns:320px 1fr;gap:36px;align-items:start}
  .related-left{display:block;padding-right:8px}
  /* Article area uses asymmetric inner layout: summary narrow left, content offset right */
  .article{padding-left:8px}
  .article-header{padding-top:6px}
  .lead{max-width:52%;margin-left:0}
  .content-wrapper{margin-top:18px;padding-left:6%;}
  .content{max-width:78ch;font-size:16px}
  /* Ensure desktop has a distinct spatial swap: related left, content right */
  .related-list a{display:block;padding:6px 2px;color:var(--accent);border-left:3px solid transparent}
  .related-list a:hover{border-left-color:var(--accent)}
  .related-left .related-list{padding-top:4px}
  /* related-bottom not used on desktop */
  .related-bottom{display:none}
}

/* Mobile layout (max-width:767px) - required */
@media (max-width:767px){
  .page-wrap{padding:18px 12px 40px}
  .page-grid{grid-template-columns:1fr}
  .related-left{display:none}
  .article{padding:0}
  .title{font-size:22px;line-height:1.12}
  .meta{flex-direction:row;gap:8px;font-size:12px}
  .lead{margin-top:8px}
  .content{font-size:15px}
  /* Mobile: linear order required by mobile_contract — title, 摘要, 正文, FAQ, 推荐 */
  /* related-bottom becomes visible as three-column short cards */
  .related-bottom{display:block}
  .related-grid{grid-template-columns:repeat(3,1fr)}
  /* Ensure no horizontal scroll at 320px */
  body,html{overflow-x:hidden}
  .content{word-break:break-word}
  .ad{font-size:13px}
}

/* Intermediate widths (768px - 1023px) keep moderate density */
@media (min-width:768px) and (max-width:1023px){
  .page-grid{max-width:960px}
  .title{font-size:28px}
  .lead{max-width:100%}
  .related-left{display:none}
  .related-bottom{display:block}
}

/* Accessibility & small tweaks */
.title, .section-title, .aside-title{color:var(--ink)}
.meta time{color:var(--muted)}