:root{
  --bg:#f7f8fa; --panel:#fff; --ink:#1f2328; --muted:#5b6570;
  --brand:#0b6bcb; --brand2:#0a4f92; --line:#e4e7eb; --code-bg:#f6f8fa;
  --sidebar:#0f1b2d; --sidebar-ink:#c9d4e2;
}
*{box-sizing:border-box}
html,body{margin:0;padding:0}
body{font-family:-apple-system,"Segoe UI","Microsoft YaHei",Roboto,Helvetica,Arial,sans-serif;
  color:var(--ink);background:var(--bg);line-height:1.75;font-size:16px}
a{color:var(--brand);text-decoration:none}
a:hover{text-decoration:underline}

/* sidebar */
.sidebar{position:fixed;top:0;left:0;bottom:0;width:280px;background:var(--sidebar);
  color:var(--sidebar-ink);padding:18px 14px;overflow-y:auto;z-index:20;transition:transform .25s}
.sidebar .brand{font-size:18px;font-weight:700;margin-bottom:14px}
.sidebar .brand a{color:#fff}
.nav-item{display:flex;align-items:center;gap:10px;padding:9px 10px;border-radius:8px;color:var(--sidebar-ink);font-size:14.5px}
.nav-item:hover{background:rgba(255,255,255,.08);text-decoration:none}
.nav-item.active{background:var(--brand);color:#fff}
.nav-idx{display:inline-flex;width:22px;height:22px;border-radius:6px;background:rgba(255,255,255,.12);
  align-items:center;justify-content:center;font-size:12px;flex:none}
.nav-item.active .nav-idx{background:rgba(255,255,255,.28)}
.nav-sep{height:1px;background:rgba(255,255,255,.12);margin:12px 4px}
.nav-foot{margin-top:18px;font-size:11.5px;color:#7e8da0;padding:0 10px;line-height:1.6}

/* content */
.content{margin-left:280px;padding:40px 56px 80px;max-width:980px}
.doc{background:var(--panel);border:1px solid var(--line);border-radius:14px;padding:40px 46px;box-shadow:0 1px 3px rgba(0,0,0,.04)}
.doc h1{font-size:30px;line-height:1.3;margin:0 0 24px;padding-bottom:16px;border-bottom:2px solid var(--line)}
.doc h2{font-size:24px;margin:38px 0 14px;padding-top:6px}
.doc h3{font-size:19px;margin:28px 0 10px}
.doc p{margin:14px 0}
.doc img.doc-img{max-width:100%;height:auto;border:1px solid var(--line);border-radius:8px;margin:6px 4px 6px 0;vertical-align:middle;background:#fff}
figure{margin:22px 0;text-align:center;background:var(--code-bg);border:1px solid var(--line);border-radius:10px;padding:16px}
figure img{max-width:100%}
figcaption{color:var(--muted);font-size:14px;margin-top:10px}

code{font-family:"SFMono-Regular",Consolas,"Liberation Mono",Menlo,monospace}
:not(pre)>code{background:#eceff3;padding:.12em .4em;border-radius:5px;font-size:.9em;color:#b02a37}
pre.code-block{background:var(--code-bg);border:1px solid var(--line);border-radius:10px;padding:16px 18px;overflow:auto;font-size:13.5px;line-height:1.6}
pre.code-block code{background:none;padding:0;color:inherit;font-size:13.5px}

table{border-collapse:collapse;width:100%;margin:18px 0;font-size:14.5px}
th,td{border:1px solid var(--line);padding:9px 12px;text-align:left}
th{background:var(--code-bg)}
blockquote{margin:16px 0;padding:10px 18px;border-left:4px solid var(--brand);background:#f0f6ff;color:#33475b;border-radius:0 8px 8px 0}

/* tabs */
.tabs{border:1px solid var(--line);border-radius:10px;margin:20px 0;overflow:hidden}
.tab-bar{display:flex;flex-wrap:wrap;background:var(--code-bg);border-bottom:1px solid var(--line)}
.tab-btn{border:0;background:none;padding:10px 18px;font-size:14px;cursor:pointer;color:var(--muted);border-bottom:2px solid transparent}
.tab-btn:hover{color:var(--ink)}
.tab-btn.active{color:var(--brand);border-bottom-color:var(--brand);background:#fff;font-weight:600}
.tab-panel{display:none;padding:6px 20px 16px}
.tab-panel.active{display:block}
.hands-on{border-left:4px solid #2da44e;background:#f6fef9;padding:10px 18px;border-radius:0 8px 8px 0;margin:14px 0}
.hands-on :first-child{margin-top:8px}

/* chart */
.chart{margin:22px 0;border:1px solid var(--line);border-radius:10px;padding:16px;background:#fff}
.chart-title{font-size:13px;color:var(--muted);margin-bottom:8px}
.chart .mermaid{text-align:center;color:var(--muted);font-size:13px;background:none;border:0;padding:6px 0}

/* spoiler */
details.spoiler{margin:16px 0;border:1px solid var(--line);border-radius:10px;background:var(--code-bg);padding:2px 0}
details.spoiler>summary{cursor:pointer;padding:12px 18px;font-weight:600;list-style:none}
details.spoiler>summary::-webkit-details-marker{display:none}
details.spoiler>summary::before{content:"▸ ";color:var(--brand)}
details.spoiler[open]>summary::before{content:"▾ "}
.spoiler-body{padding:4px 18px 14px}

/* pager */
.pager{display:flex;justify-content:space-between;gap:16px;margin-top:44px;padding-top:22px;border-top:1px solid var(--line)}
.pager-link{flex:1;max-width:46%;border:1px solid var(--line);border-radius:10px;padding:12px 16px;color:var(--ink)}
.pager-link:hover{border-color:var(--brand);text-decoration:none}
.pager-link span{display:block;font-size:12px;color:var(--muted)}
.pager-link.next{text-align:right}

/* home cards */
.card-grid{display:grid;grid-template-columns:repeat(auto-fill,minmax(280px,1fr));gap:16px;margin:26px 0}
.card{display:flex;gap:14px;align-items:center;border:1px solid var(--line);border-radius:12px;padding:18px;background:#fff;color:var(--ink)}
.card:hover{border-color:var(--brand);box-shadow:0 4px 14px rgba(11,107,203,.12);text-decoration:none;transform:translateY(-1px)}
.card-idx{width:44px;height:44px;flex:none;border-radius:10px;background:linear-gradient(135deg,var(--brand),var(--brand2));color:#fff;display:flex;align-items:center;justify-content:center;font-size:20px;font-weight:700}
.card-title{font-size:16px;font-weight:600}
.card-sub{font-size:13px;color:var(--muted)}
.note{margin-top:26px;padding:16px 20px;background:#fff8e6;border:1px solid #f0d98c;border-radius:10px;color:#6b5900;font-size:14px}

.menu-toggle{display:none}

/* responsive */
@media (max-width:960px){
  .sidebar{transform:translateX(-100%)}
  body.nav-open .sidebar{transform:translateX(0);box-shadow:0 0 40px rgba(0,0,0,.4)}
  .content{margin-left:0;padding:16px}
  .doc{padding:22px 18px}
  .menu-toggle{display:block;position:fixed;top:12px;left:12px;z-index:30;background:var(--brand);color:#fff;
    width:40px;height:40px;border-radius:8px;text-align:center;line-height:40px;cursor:pointer;font-size:18px}
  .doc h1{font-size:24px}
  pre.code-block{font-size:12.5px}
}