:root{--bg:#f3f5f9;--bg2:#e9edf5;--card:#fff;--card2:#f1f3f8;--line:rgba(15,23,42,.1);--text:#1e293b;--muted:#64748b;--a:#4f46e5;--b:#0891b2;--grad:linear-gradient(135deg,#4f46e5,#0891b2);--r:18px;color-scheme:light;--hd:#0f172a;--body:#334155;--lk:#4f46e5;--lkh:#4338ca;--hdr:rgba(243,245,249,.8);--hdr2:rgba(243,245,249,.98);--w06:rgba(15,23,42,.06);--w12:rgba(15,23,42,.12);--w03:rgba(15,23,42,.03);--w20:rgba(15,23,42,.2);--w09:rgba(15,23,42,.08);--g2:#4f46e5;--g3:#0891b2;--g2b:#6366f1;--cd:#0e7490;--lead:#475569;--cdbg:#eef0fb;--prebg:#f8fafc;--call:#334155;--cp:#64748b;--lg:#94a3b8;--onb:#fff}
html.dark{--bg:#070b14;--bg2:#0b1120;--card:#0f1629;--card2:#131c33;--line:#1c2740;--text:#e6ebf5;--muted:#93a0b8;--a:#6366f1;--b:#22d3ee;--grad:linear-gradient(135deg,#6366f1,#22d3ee);--r:18px;color-scheme:dark;--hd:#fff;--body:#cbd5e6;--lk:#7dd3fc;--lkh:#bae6fd;--hdr:rgba(7,11,20,.72);--hdr2:rgba(7,11,20,.97);--w06:rgba(255,255,255,.06);--w12:rgba(255,255,255,.12);--w03:rgba(255,255,255,.03);--w20:rgba(255,255,255,.2);--w09:rgba(255,255,255,.09);--g2:#a5b4fc;--g3:#67e8f9;--g2b:#c7d2fe;--cd:#a5f3fc;--lead:#c3cde0;--cdbg:#141c33;--prebg:#0a1020;--call:#d5dcf0;--cp:#6b7893;--lg:#5b6680;--onb:#04101f}
*{box-sizing:border-box}
html{scroll-behavior:smooth;-webkit-text-size-adjust:100%}
body{margin:0;background:var(--bg);color:var(--text);font:16px/1.85 -apple-system,BlinkMacSystemFont,"PingFang SC","Hiragino Sans GB","Microsoft YaHei","Noto Sans CJK SC",sans-serif;-webkit-font-smoothing:antialiased;overflow-x:hidden}
body.home::before{content:"";position:absolute;inset:0 0 auto 0;height:760px;background:radial-gradient(800px 420px at 78% -5%,rgba(99,102,241,.35),transparent 65%),radial-gradient(640px 380px at 8% 8%,rgba(34,211,238,.18),transparent 65%);pointer-events:none;z-index:-1}
a{color:var(--lk);text-decoration:none}
a:hover{color:var(--lkh);text-decoration:underline;text-underline-offset:3px}
a:focus-visible,.btn:focus-visible,label:focus-visible{outline:2px solid var(--b);outline-offset:3px;border-radius:6px}
img,svg{max-width:100%}
.wrap{max-width:1080px;margin:0 auto;padding:0 24px}
.skip{position:absolute;left:-999px;top:0;background:var(--b);color:#001;padding:8px 14px;z-index:99}
.skip:focus{left:8px;top:8px}

/* header */
.site-header{position:sticky;top:0;z-index:50;background:var(--hdr);backdrop-filter:saturate(1.4) blur(14px);-webkit-backdrop-filter:saturate(1.4) blur(14px);border-bottom:1px solid var(--w06)}
.bar{display:flex;align-items:center;justify-content:space-between;height:64px;gap:16px}
.brand{display:flex;align-items:center;gap:10px;color:var(--hd);font-weight:700;font-size:17px;letter-spacing:.3px;white-space:nowrap}
.brand:hover{text-decoration:none;color:var(--hd)}
.main-nav ul{display:flex;gap:2px;list-style:none;margin:0;padding:0}
.main-nav a{display:block;padding:6px 12px;border-radius:999px;color:var(--muted);font-size:14.5px;white-space:nowrap}
.main-nav a:hover{color:var(--hd);background:var(--w06);text-decoration:none}
.main-nav a[aria-current=page]{color:var(--hd);background:rgba(99,102,241,.22)}
.nav-toggle{position:absolute;opacity:0;pointer-events:none}
.burger{display:none;width:40px;height:40px;border-radius:10px;cursor:pointer;flex-direction:column;justify-content:center;align-items:center;gap:5px}
.burger span{display:block;width:20px;height:2px;background:var(--hd);border-radius:2px;transition:.2s}

/* home */
.home-body{max-width:1080px;margin:0 auto;padding:0 24px 40px}
.hero{text-align:center;padding:120px 0 96px}
.eyebrow{display:inline-block;margin:0 0 22px;padding:6px 16px;border:1px solid var(--w12);border-radius:999px;color:var(--muted);font-size:13.5px;letter-spacing:2px;background:var(--w03)}
.hero h1{margin:0;font-size:clamp(40px,7.5vw,76px);line-height:1.12;font-weight:800;letter-spacing:1px;background:linear-gradient(90deg,var(--hd) 10%,var(--g2) 55%,var(--g3));-webkit-background-clip:text;background-clip:text;color:transparent}
.hero-sub{max-width:640px;margin:26px auto 0;font-size:clamp(16px,2.2vw,20px);color:var(--muted);line-height:1.8}
.btns{display:flex;gap:14px;justify-content:center;flex-wrap:wrap;margin-top:42px}
.btn{display:inline-block;padding:14px 30px;border-radius:999px;font-weight:600;font-size:16px;border:1px solid transparent;transition:transform .15s,box-shadow .15s,background .15s}
.btn:hover{text-decoration:none;transform:translateY(-2px)}
.btn.primary{background:var(--grad);color:var(--onb);box-shadow:0 10px 30px -8px rgba(99,102,241,.7)}
.btn.primary:hover{color:var(--onb);box-shadow:0 14px 36px -8px rgba(34,211,238,.6)}
.btn.ghost{color:var(--hd);border-color:var(--w20);background:var(--w03)}
.btn.ghost:hover{color:var(--hd);background:var(--w09)}
.section{padding:64px 0 8px}
.section h2{margin:0 0 18px;font-size:clamp(26px,4vw,36px);line-height:1.3;font-weight:800;letter-spacing:.5px;text-align:center;color:var(--hd)}
.section-lead{max-width:760px;margin:0 auto;color:var(--muted);text-align:center;font-size:17px}
.section .cards{margin-top:34px}
.cards.three{grid-template-columns:repeat(3,1fr)}
.tile{height:100%;padding:26px 24px;background:var(--card);border:1px solid var(--line);border-radius:var(--r)}
.tile strong{display:block;font-size:18px;color:var(--hd);margin-bottom:8px}
.tile span{color:var(--muted);font-size:15px;line-height:1.75}
.steps{list-style:none;counter-reset:s;margin:34px 0 0;padding:0;display:grid;grid-template-columns:repeat(3,1fr);gap:18px}
.steps li{counter-increment:s;position:relative;background:var(--card);border:1px solid var(--line);border-radius:var(--r);padding:30px 26px 26px}
.steps li::before{content:"0" counter(s);display:block;font-size:34px;font-weight:800;line-height:1;margin-bottom:14px;background:var(--grad);-webkit-background-clip:text;background-clip:text;color:transparent}
.steps strong{display:block;font-size:18px;color:var(--hd);margin-bottom:6px}
.steps span{color:var(--muted);font-size:15px;line-height:1.75}
.faq-list{max-width:800px;margin:34px auto 0;display:grid;gap:14px}
.faq-item{background:var(--card);border:1px solid var(--line);border-radius:var(--r);padding:22px 26px}
.faq-item h3{margin:0 0 6px;font-size:17px;color:var(--hd)}
.faq-item p{margin:0;color:var(--muted);font-size:15px}
.more{text-align:center;margin:26px 0 0}

/* cards */
.cards{list-style:none;margin:24px 0 0;padding:0;display:grid;grid-template-columns:repeat(auto-fill,minmax(236px,1fr));gap:16px}
.cards li{margin:0}
.cards a{display:flex;flex-direction:column;gap:6px;height:100%;padding:24px 22px;background:var(--card);border:1px solid var(--line);border-radius:var(--r);color:var(--text);transition:transform .18s,border-color .18s,background .18s}
.cards a:hover{text-decoration:none;transform:translateY(-4px);border-color:rgba(99,102,241,.6);background:var(--card2)}
.cards strong{font-size:17px;color:var(--hd);line-height:1.45}
.cards span{color:var(--muted);font-size:14px;line-height:1.7}

/* content pages */
.crumbs{padding:28px 0 0;font-size:13.5px}
.crumbs ol{display:flex;flex-wrap:wrap;list-style:none;margin:0;padding:0;color:var(--muted)}
.crumbs li+li::before{content:"/";margin:0 9px;opacity:.4}
.crumbs a{color:var(--muted)}
.page-head{padding:36px 0 8px;max-width:820px}
.layout{display:grid;grid-template-columns:minmax(0,1fr) 280px;gap:56px;align-items:start;margin-top:12px}
.layout.one{grid-template-columns:minmax(0,1fr)}
.prose{min-width:0}
.prose>:first-child{margin-top:28px}
.side{position:sticky;top:88px;display:flex;flex-direction:column;gap:22px;margin-top:40px;max-height:calc(100vh - 110px);overflow:auto}
.page-head h1{margin:0;padding-bottom:.08em;text-wrap:balance;font-size:clamp(30px,5vw,44px);line-height:1.28;font-weight:800;letter-spacing:.5px;background:linear-gradient(90deg,var(--hd),var(--g2b) 70%,var(--cd));-webkit-background-clip:text;background-clip:text;color:transparent}
.page-head .lead{margin:20px 0 0;font-size:18px;color:var(--lead);line-height:1.85}
.page-head .meta{margin:14px 0 0;font-size:13px;color:var(--muted)}
.toc{margin:0;padding:20px 22px;background:var(--card);border:1px solid var(--line);border-radius:var(--r)}
.toc strong{display:block;margin-bottom:6px;color:var(--hd);font-size:15px}
.toc ol{margin:0;padding-left:20px;font-size:14.5px}
.toc li{margin:5px 0;color:var(--muted);break-inside:avoid}
.prose h2{margin:64px 0 16px;font-size:clamp(23px,3.4vw,29px);line-height:1.4;font-weight:800;color:var(--hd);scroll-margin-top:86px;padding-left:16px;position:relative}
.prose h2::before{content:"";position:absolute;left:0;top:.28em;bottom:.28em;width:4px;border-radius:4px;background:var(--grad)}
.prose h3{margin:34px 0 8px;font-size:19px;color:var(--hd);line-height:1.5}
.prose p{margin:0 0 18px;color:var(--body)}
.prose ul,.prose ol{margin:0 0 20px;padding-left:24px;color:var(--body)}
.prose li{margin:7px 0}
.prose li::marker{color:var(--b)}
.prose strong{color:var(--hd)}
.prose code{padding:2px 7px;border-radius:6px;background:var(--cdbg);border:1px solid var(--line);color:var(--cd);font-size:.9em}
.prose pre{margin:0 0 22px;padding:18px 20px;overflow:auto;background:var(--prebg);border:1px solid var(--line);border-radius:14px;line-height:1.6}
.prose pre code{padding:0;background:none;border:0}
.prose table{width:100%;border-collapse:separate;border-spacing:0;margin:0 0 24px;border:1px solid var(--line);border-radius:14px;overflow:hidden;font-size:15px;display:block;overflow-x:auto}
.prose th,.prose td{padding:12px 16px;text-align:left;border-bottom:1px solid var(--line);vertical-align:top}
.prose th{background:var(--card2);color:var(--hd);white-space:nowrap}
.prose tr:last-child td{border-bottom:0}
.prose td{color:var(--body)}
.callout{margin:0 0 22px;padding:18px 22px;background:rgba(99,102,241,.1);border:1px solid rgba(99,102,241,.35);border-radius:14px}
.callout p{margin:0;color:var(--call)}
.callout.warn{background:rgba(251,191,36,.08);border-color:rgba(251,191,36,.35)}
.sitemap-list{list-style:none;padding:0}
.sitemap-list li{padding:14px 0;border-bottom:1px solid var(--line)}
.sitemap-list span{display:block;color:var(--muted);font-size:14px;margin-top:2px}
.related h2{margin:0 0 12px;font-size:15px;color:var(--hd);padding:0;font-weight:700}
.related h2::before{display:none}
.related .cards{grid-template-columns:1fr;gap:10px;margin:0}
.related .cards a{padding:14px 16px;border-radius:14px}
.related .cards strong{font-size:14.5px}
.related .cards span{font-size:12.5px}

/* footer */
.site-footer{margin-top:96px;border-top:1px solid var(--line);background:var(--bg2);padding:44px 0 36px;text-align:center}
.foot-nav{list-style:none;margin:0 0 22px;padding:0;display:flex;flex-wrap:wrap;gap:6px 22px;justify-content:center;font-size:14px}
.foot-nav a{color:var(--muted)}
.foot-nav a:hover{color:var(--hd)}
.copy{margin:0 0 4px;color:var(--cp);font-size:13px}
.legal{margin:0;color:var(--lg);font-size:12px}

@media(max-width:900px){
.steps,.cards.three{grid-template-columns:1fr}
}
@media(max-width:960px){
.layout{grid-template-columns:minmax(0,1fr);gap:0}
.side{display:contents}
.toc{order:-1;margin:20px 0 0}
.related{order:2;margin-top:56px}
.related .cards{grid-template-columns:repeat(auto-fill,minmax(220px,1fr))}
.prose>:first-child{margin-top:32px}
}
@media(max-width:1000px){
.burger{display:flex}
.main-nav{display:none;position:absolute;left:0;right:0;top:64px;background:var(--hdr2);border-bottom:1px solid var(--line);padding:10px 16px 18px}
.main-nav ul{flex-direction:column;gap:2px}
.main-nav a{padding:12px 14px;border-radius:12px;font-size:16px}
.nav-toggle:checked~.main-nav{display:block}
.nav-toggle:checked+.burger span:nth-child(1){transform:translateY(7px) rotate(45deg)}
.nav-toggle:checked+.burger span:nth-child(2){opacity:0}
.nav-toggle:checked+.burger span:nth-child(3){transform:translateY(-7px) rotate(-45deg)}
.nav-toggle:focus-visible+.burger{outline:2px solid var(--b)}
}
@media(max-width:600px){
body{font-size:15.5px}
.wrap,.home-body{padding-left:18px;padding-right:18px}
.hero{padding:76px 0 64px}
.btn{padding:13px 26px;width:100%;max-width:300px;text-align:center}
.section{padding-top:48px}
.cards{grid-template-columns:1fr 1fr;gap:12px}
.cards.three{grid-template-columns:1fr}
.cards a{padding:18px 16px}
.cards strong{font-size:15.5px}
.cards span{font-size:13px}
.prose h2{margin-top:48px}
}
@media(max-width:380px){.cards{grid-template-columns:1fr}}
@media(prefers-reduced-motion:reduce){*{transition:none!important;scroll-behavior:auto!important}}

/* figures */
figure{margin:0}
.fig,.hero-fig{margin:30px 0;padding:0}
.fig img,.hero-fig img{display:block;width:100%;height:auto;border-radius:16px;border:1px solid var(--line);box-shadow:0 12px 36px rgba(0,0,0,.35);background:var(--prebg)}
.hero-fig{margin:6px 0 26px}
.hero-fig img{aspect-ratio:1200/630;max-height:420px;object-fit:cover}
figcaption{margin-top:10px;font-size:13px;line-height:1.6;color:var(--muted);text-align:center}
@media(max-width:640px){.fig,.hero-fig{margin:22px 0}.hero-fig{margin-top:0}.fig img,.hero-fig img{border-radius:12px}figcaption{font-size:12.5px}}

html.embed body{background:transparent}html.embed body.home::before{display:none}html.embed .site-header,html.embed .site-footer{display:none}

/* 新窗口链接标记：新窗口打开的链接后加 ↗ */
a[target="_blank"]::after{content:"↗";display:inline-block;margin-left:3px;font-size:.85em;text-decoration:none}