:root{--blue:#2563eb;--green:#16a34a;--ink:#1e293b;--mut:#64748b;--bg:#f8fafc;--card:#fff;--line:#e2e8f0;--crest:#b45309;}
*{box-sizing:border-box}
body{margin:0;font-family:system-ui,-apple-system,"Segoe UI",Roboto,"Helvetica Neue",Arial,"PingFang SC","Hiragino Sans GB","Microsoft YaHei",sans-serif;color:var(--ink);background:var(--bg);line-height:1.65}
.wrap{max-width:1020px;margin:0 auto;padding:18px}
h1{font-size:24px;margin:6px 0 4px}
h2{font-size:19px;margin:24px 0 8px;border-left:4px solid var(--blue);padding-left:10px}
h3{font-size:16px;margin:14px 0 6px}
.sub{color:var(--mut);margin:0 0 14px}
.card{background:var(--card);border:1px solid var(--line);border-radius:12px;padding:16px;margin:12px 0;box-shadow:0 1px 3px rgba(0,0,0,.04)}
table{border-collapse:collapse;width:100%;font-size:13.5px}
th,td{border:1px solid var(--line);padding:6px 9px;text-align:left;vertical-align:top}
th{background:#f1f5f9}
tr.now{background:#fef9c3}
code,pre,textarea.code{font-family:"SF Mono",ui-monospace,Menlo,Consolas,monospace}
.pipe{font-family:ui-monospace,monospace;font-size:12.5px;background:#0f172a;color:#e2e8f0;padding:12px;border-radius:8px;overflow-x:auto}
.pipe b{color:#fde047}
.badge{display:inline-block;background:#fee2e2;color:#b91c1c;border-radius:6px;padding:0 7px;font-size:12px;font-weight:700}
.crest-tag{display:inline-block;background:#fef3c7;color:var(--crest);border:1px solid #f59e0b;border-radius:6px;padding:0 7px;font-size:11.5px;font-weight:700;margin-left:6px}
.row{display:flex;gap:14px;flex-wrap:wrap;align-items:center}
label{font-weight:600;font-size:13.5px}
input[type=range]{width:220px;vertical-align:middle}
button{background:var(--blue);color:#fff;border:0;border-radius:8px;padding:8px 16px;font-size:14px;cursor:pointer}
button.ghost{background:#fff;color:var(--blue);border:1px solid var(--blue)}
button:disabled{opacity:.5;cursor:wait}
textarea.code{width:100%;min-height:200px;border:1px solid var(--line);border-radius:8px;padding:10px;font-size:12.8px;background:#0f172a;color:#e2e8f0;line-height:1.5}
.readout{font-size:14px;background:#ecfdf5;border:1px solid #a7f3d0;border-radius:8px;padding:10px;margin-top:10px}
.status{font-size:13px;color:var(--mut)}
.err{background:#fef2f2;border:1px solid #fecaca;color:#b91c1c;padding:8px;border-radius:8px;white-space:pre-wrap;font-size:13px;margin-top:8px}
.plot{width:100%}
a{color:var(--blue)}
svg{max-width:100%;height:auto;display:block;margin:6px auto}
.cap{text-align:center;color:var(--mut);font-size:12.5px;margin-top:2px}
/* top nav */
.topnav{background:#0f172a;color:#cbd5e1;padding:8px 0;position:sticky;top:0;z-index:50}
.topnav .wrap{display:flex;gap:14px;align-items:center;padding:0 18px;flex-wrap:wrap}
.topnav a{color:#cbd5e1;text-decoration:none;font-size:13.5px;padding:3px 8px;border-radius:6px}
.topnav a:hover{background:#1e293b}
.topnav a.here{background:#2563eb;color:#fff}
.topnav .brand{font-weight:800;color:#fff;font-size:15px;margin-right:6px}
/* module cards on the nav page */
.grid{display:grid;grid-template-columns:repeat(auto-fill,minmax(300px,1fr));gap:12px}
.mcard{border:1px solid var(--line);border-radius:12px;padding:14px;background:#fff;display:block;text-decoration:none;color:var(--ink);transition:box-shadow .15s}
.mcard:hover{box-shadow:0 4px 14px rgba(0,0,0,.08)}
.mcard .num{display:inline-block;width:26px;height:26px;line-height:26px;text-align:center;background:var(--blue);color:#fff;border-radius:50%;font-size:14px;font-weight:700;margin-right:8px}
.mcard .num.done{background:var(--green)}
.mcard .num.todo{background:#94a3b8}
.mcard h3{margin:0 0 6px;display:flex;align-items:center}
.mcard p{margin:4px 0;font-size:13px;color:var(--mut)}
.mcard .st{font-size:12px;font-weight:700}
.st.done{color:var(--green)} .st.now{color:var(--blue)} .st.todo{color:#94a3b8} .st.skip{color:#b45309}
/* version tabs */
.vtabs{display:flex;gap:6px;flex-wrap:wrap;margin:8px 0}
.vtabs button{background:#fff;color:var(--ink);border:1px solid var(--line);border-radius:8px;padding:6px 12px;font-size:13px}
.vtabs button.on{background:var(--blue);color:#fff;border-color:var(--blue)}
.vtabs button .crest-mini{font-size:10.5px;background:#fef3c7;color:var(--crest);border-radius:4px;padding:0 4px;margin-left:5px}
.gl{margin:10px 0;border:1px solid var(--line);border-radius:10px;overflow:hidden}
.gl summary{cursor:pointer;padding:9px 12px;background:#f8fafc;font-weight:600;font-size:14.5px;list-style:none}
.gl summary::-webkit-details-marker{display:none}
.gl summary::before{content:"\25B8  ";color:var(--blue)}
.gl[open] summary::before{content:"\25BE  "}
.gl .body{padding:6px 14px 12px}
.en{color:#475569;font-size:13.5px}
.zh{margin-top:3px}
.foot{color:var(--mut);font-size:12.5px;margin:26px 0 8px;text-align:center}
.next{display:flex;justify-content:space-between;margin:18px 0}