:root{
  --bg:#d8dce2;
  --panel:#eceff3;
  --ti:#8a929c;
  --steel:#2c333c;
  --ink:#1a1e24;
  --muted:#5c6570;
  --line:#b4bcc6;
  --hi:#c5ccd4;
  --max:1100px;
}
*{box-sizing:border-box;margin:0;padding:0}
html{background:var(--bg)}
body{font-family:"Segoe UI","Microsoft YaHei",sans-serif;color:var(--ink);background:var(--bg);line-height:1.7}
a{color:inherit;text-decoration:none}
img{display:block;max-width:100%}
ul{list-style:none}
button{font-family:inherit;cursor:pointer}
.container{width:min(var(--max),calc(100% - 40px));margin:0 auto}
.site-header{position:sticky;top:0;z-index:80;background:var(--steel);color:#e6eaee}
.topbar{display:flex;align-items:center;justify-content:space-between;gap:12px;min-height:56px;flex-wrap:wrap}
.brand{display:flex;align-items:center;gap:8px;font-weight:800;letter-spacing:.14em;font-size:12px}
.bolt{width:14px;height:14px;border:2px solid var(--hi);border-radius:2px}
.nav{display:flex;gap:16px;flex-wrap:wrap;font-size:14px;color:#b8c0c8}
.nav a[aria-current="page"]{color:#fff;border-bottom:2px solid var(--hi)}
.btn{
  display:inline-flex;align-items:center;justify-content:center;
  min-height:42px;padding:0 16px;border:1px solid var(--steel);
  background:linear-gradient(180deg,#f4f6f8,#c5ccd4);color:var(--steel);
  font-size:13px;font-weight:800;
}
.btn-fill{background:linear-gradient(180deg,#4a5560,#2c333c);border-color:#1a1e24;color:#eef2f6}
.site-header .btn{border-color:#9aa3ad;color:#eef2f6;background:transparent}
.site-header .btn-fill{background:linear-gradient(180deg,#6a7380,#2c333c)}
.kicker{display:block;font-size:11px;letter-spacing:.2em;color:var(--muted);font-weight:800;margin-bottom:8px}
.section-head{margin-bottom:20px}
.section-head h2{font-size:clamp(22px,3vw,32px);margin-bottom:8px}
.section-head p{color:var(--muted)}
.footer{padding:40px 0 20px;background:var(--steel);color:#c5ccd4}
.footer-grid{display:grid;grid-template-columns:1.4fr .8fr .8fr .9fr;gap:20px}
.footer h3,.footer h4{margin-bottom:10px;color:#fff;font-size:15px}
.footer p,.footer a,.footer li{color:#b8c0c8;font-size:14px}
.footer ul{display:grid;gap:6px}
.copyright{margin-top:20px;padding-top:12px;border-top:1px solid #3e4650;font-size:12px}
img[data-src]{min-height:80px;background:var(--hi)}
.below-fold{content-visibility:auto;contain-intrinsic-size:auto 400px}
@media(max-width:720px){.nav{display:none}.footer-grid{grid-template-columns:1fr}}