:root{
  --ink:#1c2430;
  --mute:#667085;
  --line:#e4e7ec;
  --blue:#1a4d8c;
  --paper:#f7f8fa;
}
*{box-sizing:border-box;margin:0;padding:0}
html{scroll-behavior:smooth}
body{
  font-family:"Segoe UI","PingFang SC","Noto Sans SC",sans-serif;
  background:#fff;
  color:var(--ink);
  line-height:1.55;
}
a{color:inherit;text-decoration:none}
img{max-width:100%;height:auto;display:block}
nav{
  position:sticky;top:0;z-index:10;
  display:flex;align-items:center;justify-content:space-between;
  padding:12px 8vw;background:#fff;border-bottom:1px solid var(--line);
}
.logo{font-weight:700}
.menu{display:flex;gap:22px;font-size:14px;color:var(--mute)}
.menu a:hover{color:var(--ink)}
.btn{
  display:inline-flex;align-items:center;justify-content:center;
  min-height:36px;padding:0 14px;border-radius:999px;
  background:var(--blue);color:#fff;font-size:13px;font-weight:600;
}
.hero{padding:56px 8vw 48px;text-align:center;background:var(--paper)}
.hero.compact{padding:48px 8vw 28px;text-align:left;background:#fff}
.safe{font-size:clamp(22px,3vw,32px);font-weight:700;margin-bottom:12px}
h1{font-size:clamp(20px,2.6vw,28px);font-weight:700}
.sub{margin:10px auto 0;max-width:46ch;color:var(--mute)}
.hero.compact .sub{margin-left:0}
.line{margin:12px 0 28px}
.stage{
  display:grid;grid-template-columns:1fr auto 1fr;gap:20px;align-items:center;
  max-width:860px;margin:0 auto;
}
.huge{
  display:flex;align-items:center;justify-content:center;
  width:220px;height:220px;border-radius:50%;
  background:var(--blue);color:#fff;
  font-size:28px;font-weight:700;letter-spacing:.04em;
  box-shadow:0 16px 32px rgba(26,77,140,.18);
}
.huge.sm{width:160px;height:64px;border-radius:999px;font-size:16px;margin-top:16px}
.huge:hover{filter:brightness(1.06)}
.os{
  background:#fff;border:1px solid var(--line);border-radius:16px;
  padding:20px 16px;text-align:center;
}
.os h3{margin-bottom:6px}
.os p{color:var(--mute);font-size:13px;margin-bottom:10px}
.os a{font-size:13px;color:var(--blue)}
.tags{display:flex;justify-content:center;gap:10px;list-style:none;margin:24px 0 0}
.tags li{
  padding:6px 12px;border:1px solid var(--line);border-radius:999px;
  font-size:12px;background:#fff;color:var(--mute);
}
.hero img{display:block;max-width:640px;height:200px;object-fit:cover;margin:32px auto 0;border-radius:16px;filter:grayscale(.2)}
section{padding:56px 8vw}
section>p{margin:8px 0 24px;color:var(--mute);max-width:56ch}
.cards{display:grid;grid-template-columns:repeat(3,1fr);gap:14px}
.cards article{border:1px solid var(--line);border-radius:14px;padding:18px;background:#fff}
.cards h3{font-size:15px;margin-bottom:8px}
.cards p{color:var(--mute);font-size:14px}
.cards b{display:block;margin-top:12px}
.cards small{color:var(--mute)}
.three{grid-template-columns:repeat(3,1fr)}
.split{display:grid;grid-template-columns:1fr 1fr;gap:36px;align-items:center}
.split img,.docs img{width:100%;height:280px;object-fit:cover;border-radius:16px;border:1px solid var(--line);filter:grayscale(.15)}
.split ul{list-style:none;display:grid;grid-template-columns:1fr 1fr;gap:8px;margin:16px 0 20px}
.split li{border:1px solid var(--line);border-radius:10px;padding:8px 10px;font-size:14px}
details{border-bottom:1px solid var(--line);padding:12px 0}
summary{cursor:pointer;font-weight:600}
details p{margin-top:8px;max-width:70ch;color:var(--mute)}
.ghost{color:var(--blue);font-size:14px}
.ent{margin-top:18px}
.help{display:grid;grid-template-columns:200px 1fr;gap:28px}
.help aside{display:flex;flex-direction:column;gap:8px;position:sticky;top:64px;align-self:start}
.help aside a{color:var(--mute);font-size:14px}
.help aside a:hover{color:var(--blue)}
.docs article{margin-bottom:32px}
.docs img{max-width:460px;height:210px;margin:14px 0}
.policy{margin-top:12px;padding:14px;border:1px solid var(--line);border-radius:12px}
footer{padding:36px 8vw 20px;border-top:1px solid var(--line)}
.cols{display:grid;grid-template-columns:2fr 1fr 1fr 1fr;gap:18px}
.cols h4{font-size:13px;margin-bottom:8px}
.cols a,.cols p{display:block;margin:6px 0;color:var(--mute);font-size:13px}
.copy{margin-top:18px;font-size:12px;color:var(--mute)}
@media (max-width:980px){
  .menu{display:none}
  .stage,.cards,.three,.split,.help,.cols{grid-template-columns:1fr}
  .huge{width:180px;height:180px;margin:0 auto}
}

@media (prefers-reduced-motion:reduce){html{scroll-behavior:auto}*,*::before,*::after{animation:none!important;transition:none!important}}