/* site-article.css —— 文章页整合样式（单文件） */
/* 基础变量 */
:root{
  --c-text:#111827;--c-muted:#6b7280;--c-border:#e5e7eb;--c-soft:#f8fafc;--c-bg:#ffffff;
  --c-brand:#0ea5e9;--c-brand-2:#3b82f6;--radius:16px;--shadow:0 6px 24px rgba(0,0,0,.07);
  --container:clamp(980px,92vw,1260px);--sidew:300px;
}
*{box-sizing:border-box}
html,body{margin:0;padding:0}
body{font-family:-apple-system,BlinkMacSystemFont,"Segoe UI",Roboto,"PingFang SC","Hiragino Sans GB","Microsoft YaHei",Arial,sans-serif;background:var(--c-bg);color:var(--c-text);line-height:1.75}
a{color:var(--c-brand);text-decoration:none}
a:hover{text-decoration:underline}

/* 顶部阅读进度条 */
.progress{position:fixed;top:0;left:0;height:3px;width:0;background:linear-gradient(90deg,var(--c-brand),var(--c-brand-2));z-index:9999}

/* 布局与卡片 */
.container{width:var(--container);margin:0 auto;padding:24px}
.breadcrumb{font-size:13px;color:var(--c-muted);margin:8px 0 16px}
.breadcrumb a{color:var(--c-muted)}
.grid{display:grid;grid-template-columns:minmax(260px,var(--sidew)) 1fr;gap:28px;align-items:start}
@media (max-width:1024px){.grid{grid-template-columns:1fr}}
.card{background:#fff;border:1px solid var(--c-border);border-radius:var(--radius);box-shadow:var(--shadow)}

/* 左侧栏：目录 + 联系方式 */
.sidebar{position:sticky;top:16px}
.toc{padding:16px}
.toc h3{margin:0 0 10px;font-size:16px}
.toc-nav{max-height:65vh;overflow:auto;padding-right:4px}
.toc-nav a{display:block;padding:6px 10px;border-radius:10px;font-size:14px;color:#64748b;text-decoration:none}
.toc-nav a:hover{background:#f8fafc}
.toc-nav a.h3{padding-left:22px}
.toc-nav a.active{background:linear-gradient(180deg,#eef6ff,#ffffff);border:1px solid #dbeafe;color:#1d4ed8;
  box-shadow:0 6px 18px rgba(29,78,216,.08)}
.toc-empty{color:#9ca3af}

.contact{margin-top:16px;padding:16px}
.contact .row{display:flex;align-items:center;gap:10px;margin:6px 0}
.btn{display:inline-block;padding:10px 14px;border-radius:12px;background:var(--c-brand);color:#fff;text-decoration:none}
.btn.secondary{background:#10b981}

/* 主体文章 */
.post{padding:24px}
.post .post-header{text-align:center}
.post h1{font-size:clamp(24px,2.3vw,34px);margin:6px 0 8px}
.meta{display:flex;flex-wrap:wrap;gap:12px;justify-content:center;color:var(--c-muted);font-size:14px}
.meta span+span::before{content:'·';margin:0 8px;color:#cbd5e1}

.feature{margin:14px 0;border-radius:14px;overflow:hidden}
.feature img{width:100%;height:auto;display:block}

.entry-content{font-size:16px}
.entry-content h2{font-size:22px;margin-top:1.6em}
.entry-content h3{font-size:18px;margin-top:1.1em}
.entry-content img{max-width:100%;border-radius:10px}
.entry-content table{width:100%;border-collapse:collapse}
.entry-content th,.entry-content td{border:1px solid var(--c-border);padding:10px}

/* 标签、分享、上下篇 */
.tags{display:flex;flex-wrap:wrap;gap:8px;margin:16px 0}
.tag{font-size:12px;padding:6px 10px;background:var(--c-soft);border:1px solid var(--c-border);border-radius:999px}
.share{display:flex;gap:12px;align-items:center;border-top:1px solid var(--c-border);padding-top:16px;margin-top:16px;color:var(--c-muted)}
.pn{display:flex;justify-content:space-between;gap:10px;border-top:1px solid var(--c-border);padding-top:18px;margin-top:14px}
.pn a{display:block;padding:10px 12px;border:1px solid var(--c-border);border-radius:10px;background:var(--c-soft)}

/* 相关文章：3 列 × 2 行卡片，上图下文；自适应收缩 */
.related h3{font-size:18px;margin:0 0 10px}
.related-list{list-style:none;padding:0;margin:0;display:grid;grid-template-columns:repeat(3,1fr);gap:16px}
@media (max-width: 900px){ .related-list{ grid-template-columns:repeat(2,1fr); } }
@media (max-width: 640px){ .related-list{ grid-template-columns:1fr; } }
.related-item{display:block;padding:10px;border:1px solid var(--c-border);border-radius:12px;background:#fff}
.related-item:hover{background:var(--c-soft);text-decoration:none}
.ri-thumb{display:block;width:100%;aspect-ratio:4/3;border-radius:10px;overflow:hidden;background:#f1f5f9;border:1px solid var(--c-border);margin-bottom:8px}
.ri-thumb img{width:100%;height:100%;object-fit:cover;display:block}
.ri-title{display:block;font-size:15px;line-height:1.6;color:#0f172a;overflow-wrap:anywhere}