/* 全局变量与版式 */
:root{
  --bg:#fbfaf6; /* 轻纸张底色 */
  --text:#111;
  --muted:#666;
  --accent:#b90d0d; /* 朱红强调 */
  --max-width-desktop:1320px; /* 在 1120-1440 范围内，采用中点 */
  --side-width:280px;
  --gap:28px;
  --title-font-family: Georgia, 'Times New Roman', serif;
  --content-font-family: system-ui, -apple-system, 'Segoe UI', Roboto, 'Helvetica Neue', Arial, 'Noto Sans', sans-serif;
}

/* 基础重置 */
*{box-sizing:border-box}
html,body{height:100%}
body{
  margin:0;
  color:var(--text);
  background:var(--bg);
  font-family:var(--content-font-family);
  line-height:1.65;
  -webkit-font-smoothing:antialiased;
  -moz-osx-font-smoothing:grayscale;
}

/* 站头：左右分置编辑部报头，站名居中 */
.site-header{padding:12px 20px;border-bottom:1px solid rgba(0,0,0,0.06);background:linear-gradient(90deg,transparent,transparent)}
.header-row{display:flex;align-items:center;justify-content:space-between;max-width:var(--max-width-desktop);margin:0 auto}
.header-left,.header-right{flex:1}
.header-center{flex:0 0 auto;text-align:center}
.site-title{font-weight:700;color:var(--text);text-decoration:none;font-size:18px}
.nav-item{color:var(--muted);margin-right:14px;font-size:13px}
.nav-item:last-child{margin-right:0}

/* 页面主体容器：桌面端宽度限制按合同 */
.page-wrap{padding:30px 20px 60px;display:flex;justify-content:center}
.sheet-area{width:100%;max-width:var(--max-width-desktop)}

/* 文章总体布局：桌面为偏移纸张效果；移动端单列 */
.article{background:transparent;margin:0}
.article-meta{font-size:13px;color:var(--muted);display:flex;gap:12px;align-items:center}
.article-title{font-family:var(--title-font-family);font-weight:700;color:var(--text);margin:12px 0 8px;font-size:28px;line-height:1.06;display:block}
.summary{color:var(--muted);margin:0 0 18px}

/* 内容与边注组合：非对称双栏 */
.content-frame{display:grid;grid-template-columns:1fr var(--side-width);gap:var(--gap);align-items:start}
.content-main{min-width:0}
.side-note{font-size:13px;color:var(--muted)}
.side-block{margin-bottom:14px}
.side-label{font-weight:600;color:var(--accent);font-size:12px;margin-bottom:6px}
.side-value{color:var(--text)}

/* 视觉签名：正文双层基线网格感 */
.content-text{
  background-color:transparent;
  padding-right:12px;
  color:var(--text);
  /* 双层基线：两套重复横线叠加，细线与次密线 */
  background-image:
    repeating-linear-gradient(0deg, rgba(0,0,0,0.03) 0px, rgba(0,0,0,0.03) 1px, transparent 1px, transparent 22px),
    repeating-linear-gradient(0deg, rgba(0,0,0,0.02) 0px, rgba(0,0,0,0.02) 1px, transparent 1px, transparent 44px);
  background-size:100% 22px,100% 44px;
  background-position: left top, left top;
  padding:8px 8px 20px 0;
}

.content-text p{margin:0 0 12px}
.content-text h2, .content-text h3{margin:18px 0 8px}
.content-text ul, .content-text ol{margin:0 0 12px 20px}

/* 广告区样式（不可悬浮/覆盖） */
.ad-zone{margin:20px 0;padding:10px;border-top:1px dashed rgba(0,0,0,0.06);color:var(--muted);font-size:13px}
.ad-top{max-width:var(--max-width-desktop);margin:12px auto}

/* FAQ 与 相关阅读 布局 */
.faq-section h2, .related-section h2{font-size:16px;margin:18px 0 10px;color:var(--accent)}
.faq-grid{display:grid;grid-template-columns:1fr 1fr;gap:18px}
.faq-grid dl{margin:0}
.faq-grid dt{font-weight:700;margin-bottom:6px}
.faq-grid dd{margin:0 0 12px;color:var(--muted)}

.related-grid{display:grid;grid-template-columns:repeat(3,1fr);gap:14px}
.related-grid > *{padding:10px;border-left:3px solid transparent;border-top:0;border-bottom:0}
.related-grid a{color:var(--text);text-decoration:none}

/* 页脚 */
.site-footer{border-top:1px solid rgba(0,0,0,0.06);padding:18px 20px;text-align:center;color:var(--muted);font-size:13px}

/* 桌面端专属规则（>=1024px）-- 必需有独立桌面结构 */
@media (min-width:1024px){
  .page-wrap{padding:48px 20px}
  .sheet-area{min-width:1120px;max-width:1440px}

  /* 偏移纸张效果：文章像偏移纸张一样置于宽背景上，标题向左越出正文基线 */
  .article{position:relative}
  .content-frame{align-items:start}
  .article-title{font-size:40px;margin-left:-56px;padding-left:8px;border-top:3px solid var(--accent);border-bottom:1px solid rgba(0,0,0,0.06);display:inline-block}
  .content-main{transform:translateX(-40px)}
  .side-note{position:relative;top:4px}
  .related-grid{grid-template-columns:repeat(3,1fr)}
}

/* 手机端规则（<=767px）：取消偏移与越界，回到安全边距，FAQ 单列 */
@media (max-width:767px){
  .header-row{padding:0 6px}
  .page-wrap{padding:16px 12px}
  .sheet-area{max-width:100%}

  .content-frame{grid-template-columns:1fr;gap:12px}
  .side-note{order:2}
  .content-main{transform:none}
  .article-title{margin-left:0;font-size:20px;border-top:none;border-bottom:1px solid rgba(0,0,0,0.04);padding-top:6px}

  .faq-grid{grid-template-columns:1fr}
  .related-grid{grid-template-columns:1fr}

  /* 宽度320时避免横向滚动 */
  body{min-width:0}
}

/* 中间断点（768-1023）采用较紧凑布局但非桌面偏移 */
@media (min-width:768px) and (max-width:1023px){
  .sheet-area{max-width:880px}
  .article-title{font-size:26px;margin-left:0}
  .content-frame{grid-template-columns:1fr var(--side-width)}
}

/* 可视性与可访问性微调 */
h1{line-height:1.02}
a{color:var(--accent)}