:root{
  --bg:#ffffff;
  --bg-soft:#f6f8fb;
  --bg-panel:#fbfcfe;
  --ink:#0f172a;
  --ink-2:#334155;
  --ink-3:#64748b;
  --line:#e6ebf2;
  --brand:#2d6bff;
  --brand-soft:#eaf1ff;
  --p0:#e11d48;
  --p0-soft:#fff1f3;
  --p1:#d97706;
  --p1-soft:#fff7ed;
  --p2:#0d9488;
  --p2-soft:#ecfdf8;
  --p3:#64748b;
  --p3-soft:#f1f5f9;
  --radius:14px;
  --shadow:0 1px 2px rgba(15,23,42,.04),0 8px 24px rgba(15,23,42,.06);
  --maxw:1080px;
  font-synthesis:none;
}
*{box-sizing:border-box}
html{scroll-behavior:smooth}
body{
  margin:0;background:var(--bg);color:var(--ink);
  font-family:-apple-system,BlinkMacSystemFont,"Segoe UI","PingFang SC","Hiragino Sans GB","Microsoft YaHei",sans-serif;
  line-height:1.7;font-size:16px;-webkit-font-smoothing:antialiased;
}
a{color:var(--brand);text-decoration:none}
a:hover{text-decoration:underline}
.wrap{max-width:var(--maxw);margin:0 auto;padding:0 24px}

/* top nav */
.topnav{position:sticky;top:0;z-index:20;background:rgba(255,255,255,.86);backdrop-filter:blur(10px);
  border-bottom:1px solid var(--line)}
.topnav .wrap{display:flex;align-items:center;gap:18px;height:60px}
.brand{font-weight:800;letter-spacing:-.02em;color:var(--ink);font-size:17px;white-space:nowrap}
.brand b{color:var(--brand)}
.navlinks{display:flex;gap:4px;flex-wrap:wrap;margin-left:auto;overflow-x:auto;align-items:center}
.navlinks a{color:var(--ink-2);font-size:14px;padding:7px 11px;border-radius:9px;white-space:nowrap}
.navlinks a:hover{background:var(--bg-soft);text-decoration:none}
.navlinks a.active{background:var(--brand-soft);color:var(--brand);font-weight:600}

/* language switcher */
.lang-switch{position:relative;flex-shrink:0;margin-left:8px}
.lang-current{background:#1e293b;color:#fff;border:none;border-radius:999px;padding:7px 14px;font-size:13px;font-weight:600;cursor:pointer;display:flex;align-items:center;gap:6px;white-space:nowrap}
.lang-current::after{content:"";width:0;height:0;border-left:4px solid transparent;border-right:4px solid transparent;border-top:4px solid currentColor;opacity:.7}
.lang-menu{position:absolute;top:calc(100% + 8px);right:0;background:#1e293b;border-radius:12px;box-shadow:0 12px 28px rgba(0,0,0,.28);padding:6px;min-width:150px;display:none;z-index:50}
.lang-switch.open .lang-menu{display:flex;flex-direction:column}
.lang-menu a{color:#e2e8f0;font-size:13px;padding:8px 12px;border-radius:8px;white-space:nowrap}
.lang-menu a:hover{background:#334155;text-decoration:none;color:#fff}
.lang-menu a.active{background:#334155;color:#fff;font-weight:600}

/* hero */
.hero{background:linear-gradient(180deg,#f8fbff 0%,#ffffff 100%);border-bottom:1px solid var(--line)}
.hero .wrap{padding:54px 24px 46px}
.eyebrow{display:inline-block;font-size:13px;font-weight:600;color:var(--brand);background:var(--brand-soft);
  padding:5px 12px;border-radius:999px;margin-bottom:16px}
.hero h1{font-size:38px;line-height:1.2;margin:0 0 14px;letter-spacing:-.025em;font-weight:800}
.hero p.lead{font-size:18px;color:var(--ink-2);max-width:720px;margin:0}
.stats{display:flex;gap:28px;flex-wrap:wrap;margin-top:30px}
.stat{display:flex;flex-direction:column}
.stat b{font-size:26px;color:var(--ink);font-weight:800;letter-spacing:-.02em}
.stat span{font-size:13px;color:var(--ink-3)}

/* sections */
section{padding:40px 0}
h2{font-size:26px;letter-spacing:-.02em;margin:0 0 8px;font-weight:800}
h3{font-size:19px;margin:30px 0 10px;font-weight:700}
h4{font-size:16px;margin:18px 0 6px;font-weight:700;color:var(--ink)}
.sub{color:var(--ink-3);margin:0 0 22px;font-size:15px}
p{color:var(--ink-2);margin:10px 0}
ul,ol{color:var(--ink-2);padding-left:22px}
li{margin:5px 0}

/* cards */
.grid{display:grid;gap:16px}
.grid.c2{grid-template-columns:repeat(2,1fr)}
.grid.c3{grid-template-columns:repeat(3,1fr)}
.card{background:var(--bg-panel);border:1px solid var(--line);border-radius:var(--radius);padding:20px;box-shadow:var(--shadow)}
.card h4{margin-top:0}
.card p{margin:6px 0 0;font-size:14.5px}

/* priority badges */
.badge{display:inline-flex;align-items:center;font-size:12px;font-weight:700;padding:2px 9px;border-radius:999px;letter-spacing:.02em}
.badge.P0{background:var(--p0-soft);color:var(--p0)}
.badge.P1{background:var(--p1-soft);color:var(--p1)}
.badge.P2{background:var(--p2-soft);color:var(--p2)}
.badge.P3{background:var(--p3-soft);color:var(--p3)}

/* tables */
table{width:100%;border-collapse:collapse;margin:14px 0;font-size:14.5px;background:#fff;border:1px solid var(--line);border-radius:var(--radius);overflow:hidden}
th,td{text-align:left;padding:11px 13px;border-bottom:1px solid var(--line);vertical-align:top}
th{background:var(--bg-soft);color:var(--ink);font-weight:700;font-size:13.5px}
tr:last-child td{border-bottom:none}
td code,code{background:var(--bg-soft);border:1px solid var(--line);border-radius:6px;padding:1px 6px;font-size:13px;color:#0b3b8c;font-family:"SF Mono",ui-monospace,Menlo,Consolas,monospace}

/* callouts */
.note{border-left:4px solid var(--brand);background:var(--brand-soft);padding:14px 18px;border-radius:10px;margin:16px 0;color:var(--ink-2);font-size:14.5px}
.note.good{border-color:var(--p2);background:var(--p2-soft)}
.note.warn{border-color:var(--p1);background:var(--p1-soft)}
.note b{color:var(--ink)}

/* field block */
.field{border:1px solid var(--line);border-radius:var(--radius);padding:0;margin:18px 0;overflow:hidden;background:#fff;box-shadow:var(--shadow)}
.field .head{display:flex;align-items:center;gap:10px;padding:14px 18px;background:var(--bg-panel);border-bottom:1px solid var(--line)}
.field .head .zh{font-weight:700;font-size:17px}
.field .head .en{color:var(--ink-3);font-family:"SF Mono",ui-monospace,Menlo,Consolas,monospace;font-size:13px}
.field .body{padding:14px 18px}
.field .body p{margin:8px 0;font-size:14.5px}

/* footer */
footer{border-top:1px solid var(--line);background:var(--bg-soft);margin-top:30px}
footer .wrap{padding:26px 24px;color:var(--ink-3);font-size:13.5px;display:flex;justify-content:space-between;flex-wrap:wrap;gap:10px}

/* toc */
.toc{background:var(--bg-panel);border:1px solid var(--line);border-radius:var(--radius);padding:16px 20px;margin:18px 0}
.toc a{display:block;padding:4px 0;font-size:14.5px}

/* RTL adjustments */
body.rtl{direction:rtl}
body.rtl .wrap{padding:0 24px}
body.rtl .navlinks{margin-left:0;margin-right:auto}
body.rtl .lang-switch{margin-left:0;margin-right:8px}
body.rtl .lang-menu{right:auto;left:0}
body.rtl table th,body.rtl table td{text-align:right}
body.rtl ul,body.rtl ol{padding-left:0;padding-right:22px}
body.rtl .note{border-left:none;border-right:4px solid var(--brand)}

@media (max-width:720px){
  .grid.c2,.grid.c3{grid-template-columns:1fr}
  .hero h1{font-size:30px}
  table{font-size:13px}
  th,td{padding:9px 10px}
}