:root{
  --ink:#0F172A; --muted:#4A5875; --bg:#F7F8FC; --card:#FFFFFF; --line:#E2E6F0;
  --accent:#4338CA; --accent-2:#312E81; --soft:#EEF0FF; --teal:#0F766E; --warm:#B45309;
  --shadow:0 12px 32px rgba(15,23,42,.07);
}
*{box-sizing:border-box}
html{scroll-behavior:smooth}
body{margin:0;min-height:100vh;display:flex;flex-direction:column;background:var(--bg);color:var(--ink);
  font:17px/1.68 ui-sans-serif,-apple-system,"Segoe UI",Roboto,Helvetica,Arial,sans-serif;
  -webkit-font-smoothing:antialiased;text-rendering:optimizeLegibility}
main{flex:1 0 auto}
h1,h2,h3{font-family:"Iowan Old Style","Palatino Linotype",Palatino,Georgia,serif;line-height:1.16;
  letter-spacing:-.012em;color:var(--ink)}
h1{font-size:clamp(2.15rem,4.5vw,3.4rem);margin:0 0 16px;font-weight:700}
h2{font-size:clamp(1.5rem,2.5vw,2.05rem);margin:48px 0 16px;font-weight:700}
h3{font-size:1.2rem;margin:28px 0 8px;font-weight:700}
p{margin:0 0 16px;max-width:74ch;color:var(--ink)}
ul,ol{margin:0 0 20px;padding-left:22px;max-width:74ch}
li{margin:0 0 8px}
a{color:var(--accent);text-decoration:underline;text-decoration-thickness:1px;text-underline-offset:3px}
a:hover{color:var(--accent-2)}
a:focus-visible,button:focus-visible,summary:focus-visible{outline:3px solid #6366F1;outline-offset:2px;border-radius:8px}
.wrap{width:min(1120px,100% - 40px);margin:0 auto}
.skip{position:fixed;left:12px;top:-72px;background:#fff;padding:12px 16px;z-index:40;
  border-radius:10px;box-shadow:var(--shadow);font-weight:700;text-decoration:none}
.skip:focus{top:12px}
/* 导航 */
.nav{background:#fff;border-bottom:1px solid var(--line)}
.nav .wrap{display:flex;align-items:center;gap:24px;padding:14px 0;flex-wrap:nowrap}
.brand{display:flex;align-items:center;gap:10px;font-weight:800;font-size:1.04rem;color:var(--ink);
  text-decoration:none;white-space:nowrap}
.brand svg{width:30px;height:30px;display:block}
.brand:hover{color:var(--ink)}
.nav-links{display:flex;align-items:center;gap:24px;margin-left:auto;overflow-x:auto;scrollbar-width:thin}
.nav-links a{font-size:.95rem;font-weight:600;color:var(--muted);text-decoration:none;white-space:nowrap;
  padding:6px 0;border-bottom:2px solid transparent}
.nav-links a:hover{color:var(--accent-2)}
.nav-links a.on{color:var(--accent);border-bottom-color:var(--accent)}
/* Hero */
.hero{background:linear-gradient(180deg,#FFFFFF 0%,#F2F3FB 100%);border-bottom:1px solid var(--line);
  padding-top:56px}
.hero-in{display:grid;grid-template-columns:1.15fr .85fr;gap:48px;align-items:center;padding:0 0 64px}
.hero-copy{max-width:600px}
.kicker{margin:0 0 16px;font-size:.8rem;font-weight:800;letter-spacing:.09em;text-transform:uppercase;
  color:var(--teal)}
.lede{font-size:1.14rem;color:var(--muted);max-width:58ch}
.hero-cta{display:flex;flex-wrap:wrap;gap:16px;margin:24px 0 16px}
.hero-note{margin:0;font-size:.86rem;color:var(--muted)}
.hero-art img{width:100%;height:auto;display:block;border-radius:26px;box-shadow:var(--shadow)}
.hero-topic .hero-in{grid-template-columns:1.06fr .94fr;gap:44px;padding:0 0 44px}
.hero-topic h1{font-size:clamp(1.95rem,3.6vw,2.95rem)}
.hero-topic .hero-copy{max-width:640px}
.hero-topic .lede{font-size:1.06rem}
.hero-topic .hero-art img{border-radius:22px}
.btn{display:inline-flex;align-items:center;justify-content:center;min-height:46px;padding:12px 22px;
  border-radius:999px;background:var(--accent);color:#fff;font-weight:700;font-size:.97rem;
  text-decoration:none;border:1px solid var(--accent);transition:background-color .18s,transform .12s}
.btn:hover{background:var(--accent-2);color:#fff}
.btn:active{transform:scale(.985)}
.btn.ghost{background:#fff;color:var(--accent);border-color:#C7CBF5}
.btn.ghost:hover{background:var(--soft);color:var(--accent-2)}
/* 页面主体 */
.page{padding:36px 0 56px}
.page-head{max-width:820px;margin:0 0 28px}
.page-head .lede{font-size:1.08rem}
.body{max-width:820px}
.callout{background:var(--soft);border:1px solid #D7DAF8;border-left:5px solid var(--accent);
  border-radius:14px;padding:20px 22px;margin:24px 0}
.callout strong{display:block;margin-bottom:6px}
.callout p:last-child{margin-bottom:0}
.tbl-wrap{overflow-x:auto;margin:24px 0;border:1px solid var(--line);border-radius:16px;background:#fff}
table{width:100%;border-collapse:collapse;min-width:640px;font-size:.95rem}
caption{caption-side:top;text-align:left;padding:14px 18px 0;font-size:.86rem;color:var(--muted)}
th,td{padding:12px 16px;text-align:left;border-bottom:1px solid var(--line);vertical-align:top}
th{background:#F4F5FB;font-size:.82rem;letter-spacing:.04em;text-transform:uppercase;color:var(--muted);
  white-space:nowrap}
tbody tr:last-child td{border-bottom:0}
td code,code{background:#F1F2F9;border-radius:6px;padding:2px 6px;font-size:.88em;
  font-family:ui-monospace,SFMono-Regular,Menlo,Consolas,monospace}
/* 卡片阵列 */
.cards{display:grid;grid-template-columns:repeat(auto-fit,minmax(240px,1fr));gap:20px;margin:24px 0}
.card{display:flex;flex-direction:column;background:#fff;border:1px solid var(--line);border-radius:18px;
  padding:22px;text-decoration:none;color:var(--ink);box-shadow:0 2px 0 rgba(15,23,42,.02);
  transition:transform .16s,box-shadow .16s,border-color .16s}
.card:hover{transform:translateY(-2px);box-shadow:var(--shadow);border-color:#C7CBF5;color:var(--ink)}
.card .tag{font-size:.74rem;font-weight:800;letter-spacing:.08em;text-transform:uppercase;color:var(--teal);
  margin-bottom:8px}
.card h3{margin:0 0 8px;font-size:1.08rem}
.card p{margin:0;font-size:.93rem;color:var(--muted);max-width:none}
.card .go{margin-top:14px;font-size:.86rem;font-weight:700;color:var(--accent)}
/* 图 */
figure.ig{margin:28px auto;background:#fff;border:1px solid var(--line);border-radius:16px;padding:14px;
  max-width:100%;overflow-x:auto}
figure.ig img{width:auto;max-width:100%;min-width:560px;height:auto;display:block;margin:0 auto}
figure.ig figcaption{text-align:center;font-size:.82rem;color:var(--muted);margin-top:10px;max-width:70ch;
  margin-left:auto;margin-right:auto}
/* 复制块 */
.copyblock{margin:20px 0;border:1px solid var(--line);border-radius:14px;background:#fff;overflow:hidden}
.copyblock .cb-head{display:flex;align-items:center;justify-content:space-between;gap:16px;
  padding:12px 16px;background:#F4F5FB;border-bottom:1px solid var(--line)}
.copyblock .cb-head span{font-size:.8rem;font-weight:800;letter-spacing:.06em;text-transform:uppercase;
  color:var(--muted)}
.copyblock pre{margin:0;padding:16px;white-space:pre-wrap;word-break:break-word;font-size:.9rem;
  font-family:ui-monospace,SFMono-Regular,Menlo,Consolas,monospace;color:#1F2937}
.cp-btn{display:inline-grid;place-items:center;min-width:104px;min-height:34px;padding:6px 14px;
  border:1px solid #C7CBF5;border-radius:999px;background:#fff;color:var(--accent);font-weight:700;
  font-size:.82rem;cursor:pointer;font-family:inherit}
.cp-btn:hover{background:var(--soft)}
.cp-face{grid-area:1/1;transition:opacity .16s}
.cp-ok{opacity:0}
.cp-btn.on .cp-face{opacity:0}
.cp-btn.on .cp-ok{opacity:1;color:var(--teal)}
/* FAQ */
.faq{border:1px solid var(--line);border-radius:14px;background:#fff;margin:0 0 12px;padding:0 18px}
.faq summary{cursor:pointer;font-weight:700;padding:16px 0;list-style:none;display:flex;gap:12px;
  align-items:flex-start}
.faq summary::-webkit-details-marker{display:none}
.faq summary::before{content:"+";color:var(--accent);font-weight:800;line-height:1.3}
.faq[open] summary::before{content:"\2212"}
.faq .faq-a{padding:0 0 16px 22px;color:var(--muted)}
.faq .faq-a p{margin:0;max-width:70ch}
/* 相关链接 */
.related{margin:40px 0 0;padding:24px;border-radius:18px;background:#fff;border:1px solid var(--line)}
.related strong{display:block;margin-bottom:12px;font-size:.82rem;letter-spacing:.08em;text-transform:uppercase;
  color:var(--muted)}
.related ul{margin:0;padding-left:20px}
/* 页脚 */
footer.site{background:#1E1B4B;color:#C7D2FE;margin-top:56px;padding:44px 0 28px}
footer.site .cols{display:grid;grid-template-columns:1.4fr 1fr 1fr 1fr;gap:32px;
  width:min(1120px,100% - 40px);margin:0 auto}
footer.site strong{color:#fff;display:block;margin-bottom:12px;font-size:.85rem;letter-spacing:.06em;
  text-transform:uppercase}
footer.site p{margin:0;font-size:.9rem;color:#A5B4FC;max-width:34ch}
footer.site a{display:block;color:#C7D2FE;text-decoration:none;font-size:.92rem;padding:5px 0}
footer.site a:hover{color:#fff;text-decoration:underline}
footer.site .legal{width:min(1120px,100% - 40px);margin:28px auto 0;padding-top:18px;
  border-top:1px solid rgba(199,210,254,.18);font-size:.82rem;color:#A5B4FC}
footer.site .legal a{display:inline;padding:0}
/* 404 */
.nf{padding:72px 0;text-align:center}
/* 响应式 */
@media (max-width:900px){
  .hero{padding-top:40px}
  .hero-in{grid-template-columns:1fr;gap:32px;padding:0 0 48px}
  .hero-topic .hero-in{grid-template-columns:1fr;gap:28px;padding-bottom:36px}
  .hero-art{order:-1}
  .nav .wrap{flex-wrap:wrap;gap:12px}
  .nav-links{width:100%;margin-left:0;gap:20px;padding-bottom:4px}
  footer.site .cols{grid-template-columns:1fr 1fr;gap:24px}
}
@media (max-width:620px){
  body{font-size:16.5px}
  .wrap{width:min(1120px,100% - 32px)}
  .hero{padding-top:32px}
  .hero-in{padding:0 0 40px}
  .page{padding:32px 0 40px}
  figure.ig{padding:10px}
  footer.site .cols{grid-template-columns:1fr}
}
@media (prefers-reduced-motion:reduce){
  html{scroll-behavior:auto}
  *,*::before,*::after{animation-duration:.001ms!important;animation-iteration-count:1!important;
    transition-duration:.001ms!important}
  .card:hover{transform:none}
  .btn:active{transform:none}
}