:root{--bg:#fff;--fg:#2c3e50;--muted:#6b7280;--border:#e5e7eb;--accent:#3eaf7c;--side:#f7f8fa;--code:#f6f8fa;--promo:#fffbea}
@media (prefers-color-scheme:dark){:root{--bg:#1b1b1f;--fg:#dfdfd6;--muted:#9ca3af;--border:#333;--accent:#5fd3a0;--side:#161618;--code:#202127;--promo:#2a2618}}
*{box-sizing:border-box}html{scroll-behavior:smooth}
body{margin:0;font:16px/1.75 -apple-system,BlinkMacSystemFont,"Segoe UI","PingFang SC","Hiragino Sans GB","Microsoft YaHei",sans-serif;color:var(--fg);background:var(--bg)}
a{color:var(--accent);text-decoration:none}a:hover{text-decoration:underline}
.topbar{position:fixed;top:0;left:0;right:0;height:56px;display:flex;align-items:center;gap:12px;padding:0 20px;border-bottom:1px solid var(--border);background:var(--bg);z-index:20}
.brand{font-weight:700;font-size:18px;color:var(--fg)}.topbar-right{margin-left:auto;font-size:14px;color:var(--muted)}
.menu-btn{display:none;font-size:20px;background:none;border:1px solid var(--border);border-radius:6px;padding:2px 8px;color:var(--fg);cursor:pointer}
.layout{display:flex;padding-top:56px}
.sidebar{position:fixed;top:56px;bottom:0;left:0;width:280px;overflow-y:auto;padding:16px 12px 40px;border-right:1px solid var(--border);background:var(--side);font-size:14.5px}
.sb-home{display:block;padding:6px 10px;font-weight:600;color:var(--fg)}
.sb-group{margin-top:8px}.sb-group summary{cursor:pointer;padding:6px 10px;list-style:none;font-weight:600}.sb-group summary::-webkit-details-marker{display:none}
.sb-group summary::before{content:"▸";display:inline-block;width:14px;color:var(--muted);transition:.15s}.sb-group[open] summary::before{transform:rotate(90deg)}
.sb-group-title{color:var(--fg)}.sb-group ul{list-style:none;margin:0;padding:0 0 0 14px}
.sb-group li a{display:block;padding:5px 10px;border-left:2px solid transparent;color:var(--fg);opacity:.85}
.sb-group li a:hover{opacity:1;text-decoration:none;background:rgba(62,175,124,.08)}
.sidebar a.active{color:var(--accent);border-left-color:var(--accent);font-weight:600;opacity:1}
.content{margin-left:280px;margin-right:240px;flex:1;min-width:0;padding:24px 48px 64px}
.article{max-width:860px;margin:0 auto}
.article h1{font-size:2em;line-height:1.3;margin:.4em 0 .5em;border-bottom:1px solid var(--border);padding-bottom:.3em}
.article h2{font-size:1.5em;margin:2em 0 .8em;padding-bottom:.3em;border-bottom:1px solid var(--border)}
.article h3{font-size:1.25em;margin:1.6em 0 .6em}.article h4{font-size:1.05em}
.article h2 a.anchor,.article h3 a.anchor{opacity:0;margin-left:.3em;font-weight:400}.article h2:hover a.anchor,.article h3:hover a.anchor{opacity:1}
.article-meta{font-size:13px;color:var(--muted);margin:-.2em 0 1.5em;word-break:break-all}
.article img{max-width:100%;height:auto;display:block;margin:12px auto;border-radius:6px}
.article table{border-collapse:collapse;display:block;overflow-x:auto;margin:1em 0;font-size:.95em}
.article th,.article td{border:1px solid var(--border);padding:8px 12px;text-align:left;vertical-align:top}.article th{background:var(--side)}
.article blockquote{margin:1em 0;padding:.3em 1em;border-left:4px solid var(--accent);background:var(--side);color:var(--muted)}
.article code{font:.9em/1.6 "SFMono-Regular",Menlo,Consolas,monospace;background:var(--code);padding:.15em .4em;border-radius:4px}
.article pre.code-block{position:relative;background:var(--code);padding:14px 16px;border-radius:8px;overflow-x:auto;line-height:1.55}
.article pre.code-block code{background:none;padding:0;font-size:.88em}
.article pre.mermaid{background:none;text-align:center;overflow-x:auto}
.promo{border:1px dashed var(--border);background:var(--promo);border-radius:8px;padding:8px 16px;margin:1.5em 0;font-size:.95em}
.promo::before{content:"以下为原站推广内容";display:block;font-size:12px;color:var(--muted);margin-bottom:4px}
.prev-next{display:flex;justify-content:space-between;gap:16px;margin-top:48px;padding-top:20px;border-top:1px solid var(--border)}
.prev-next a{padding:10px 14px;border:1px solid var(--border);border-radius:8px;max-width:48%}
.site-footer{max-width:860px;margin:48px auto 0;padding-top:16px;border-top:1px solid var(--border);font-size:13px;color:var(--muted)}
.toc{position:fixed;top:56px;right:0;bottom:0;width:240px;overflow-y:auto;padding:24px 16px;font-size:13px;border-left:1px solid var(--border)}
.toc-title{font-weight:600;margin-bottom:8px;color:var(--muted)}.toc ul{list-style:none;margin:0;padding:0}
.toc li a{display:block;padding:3px 0 3px 10px;border-left:2px solid var(--border);color:var(--muted);line-height:1.5}
.toc li.toc-l3 a{padding-left:24px}.toc li a.active,.toc li a:hover{color:var(--accent);border-left-color:var(--accent);text-decoration:none}
.footnotes{font-size:.9em;color:var(--muted)}
.topbar-cross{font-weight:600;color:var(--accent)}
.sb-cross{color:var(--accent)!important;font-weight:600}
.cross-promo{display:flex;align-items:center;gap:16px;margin:40px 0 0;padding:18px 20px;border-radius:12px;border:1px solid var(--border);background:linear-gradient(135deg,rgba(62,175,124,.10),rgba(62,175,124,.02));position:relative}
.cross-promo .cp-badge{position:absolute;top:-10px;left:16px;font-size:11px;padding:2px 8px;border-radius:999px;background:var(--accent);color:#fff;letter-spacing:.5px}
.cross-promo .cp-body{flex:1;min-width:0}.cross-promo .cp-body strong{display:block;font-size:1.05em;margin-bottom:4px}.cross-promo .cp-body p{margin:0;font-size:.93em;color:var(--muted);line-height:1.6}
.cross-promo .cp-btn{flex-shrink:0;padding:10px 18px;border-radius:999px;background:var(--accent);color:#fff;font-weight:600;font-size:.95em;white-space:nowrap}.cross-promo .cp-btn:hover{text-decoration:none;filter:brightness(1.08)}
@media (max-width:640px){.cross-promo{flex-direction:column;align-items:flex-start}}
@media (max-width:1280px){.toc{display:none}.content{margin-right:0}}
@media (max-width:900px){.menu-btn{display:inline-block}.sidebar{transform:translateX(-100%);transition:.2s;z-index:30;width:280px}.sidebar.open{transform:none}.content{margin-left:0;padding:16px 18px 48px}.article h1{font-size:1.6em}}