*{box-sizing:border-box}
:root{
  --yellow:#ffd51e;
  --blue:#3aa9df;
  --black:#111;
  --red:#ff4038;
  --paper:#fff;
  --muted:#5d6470;
}
html{scroll-behavior:smooth}
body{
  margin:0;
  font-family:Arial,"Microsoft YaHei","PingFang SC",sans-serif;
  color:var(--black);
  background:#fff;
}
.wrap{width:min(1080px,calc(100% - 30px));margin:0 auto}
.narrow{width:min(860px,calc(100% - 30px))}
.topbar{
  position:sticky;top:0;z-index:20;
  background:var(--yellow);
  border-bottom:3px solid var(--black);
}
.nav{
  height:66px;display:flex;align-items:center;justify-content:space-between;gap:20px
}
.brand{text-decoration:none}
.brand span{
  display:inline-block;background:#fff;border:3px solid #111;
  padding:8px 15px;font-weight:900;box-shadow:4px 4px 0 #111;transform:rotate(-2deg)
}
.nav nav{display:flex;gap:24px}
.nav nav a{text-decoration:none;font-size:13px;font-weight:900}
.hero{
  position:relative;overflow:hidden;background:var(--blue);
  border-bottom:3px solid var(--black)
}
.burst{
  position:absolute;inset:-50%;
  background:repeating-conic-gradient(from 0deg,rgba(255,255,255,.12) 0deg 10deg,transparent 10deg 22deg)
}
.hero-inner{
  position:relative;z-index:2;display:grid;grid-template-columns:1.25fr .75fr;
  gap:48px;align-items:center;padding:70px 0
}
.hero-card,.device-card{
  background:#fff;border:4px solid #111;box-shadow:8px 8px 0 #111
}
.hero-card{padding:30px;transform:rotate(-1deg)}
.eyebrow{
  display:inline-block;background:var(--yellow);border:2px solid #111;
  padding:4px 8px;font-size:11px;font-weight:900;margin-bottom:12px
}
.hero h1{font-size:42px;line-height:1.05;margin:0 0 14px}
.hero p{font-size:15px;line-height:1.8;color:#333;margin:0}
.primary-btn,.download-btn,.guide-btn{
  display:inline-flex;align-items:center;justify-content:center;
  text-decoration:none;font-weight:900;border:3px solid #111;
  box-shadow:4px 4px 0 #111;transition:.15s
}
.primary-btn{margin-top:22px;background:var(--red);color:#fff;padding:12px 18px}
.primary-btn:hover,.download-btn:hover,.guide-btn:hover{
  transform:translate(2px,2px);box-shadow:2px 2px 0 #111
}
.device-card{
  padding:36px 24px;text-align:center;transform:rotate(4deg)
}
.device-icons{font-size:54px;letter-spacing:6px;margin-bottom:16px}
.section{padding:68px 0}
.bordered{border-top:2px solid #111}
.section-title{
  display:table;margin:0 auto 30px;background:#111;color:#fff;
  padding:9px 15px;font-size:19px;font-weight:900;
  transform:rotate(-2deg);box-shadow:4px 4px 0 var(--yellow)
}
.download-grid{
  display:grid;grid-template-columns:repeat(2,1fr);gap:22px
}
.download-card{
  position:relative;border:3px solid #111;background:#fff;
  padding:24px;box-shadow:6px 6px 0 #111;min-height:260px
}
.download-card:nth-child(2n){transform:rotate(.6deg)}
.download-card:nth-child(2n+1){transform:rotate(-.6deg)}
.os-row{display:flex;align-items:center;justify-content:space-between;gap:12px}
.os-icon{font-size:42px}
.status{
  background:#e9f7ec;border:2px solid #111;padding:4px 9px;font-size:10px;font-weight:900
}
.download-card h2{font-size:24px;margin:14px 0 8px}
.download-card p{color:var(--muted);font-size:13px;line-height:1.7}
.meta{
  display:grid;grid-template-columns:1fr 1fr;gap:8px;margin:18px 0
}
.meta div{border:2px solid #111;background:#f8f8f8;padding:8px 10px;font-size:11px}
.actions{display:flex;gap:10px;flex-wrap:wrap}
.download-btn{background:var(--yellow);padding:10px 15px}
.guide-btn{background:#fff;padding:10px 15px}
.disabled{opacity:.45;pointer-events:none}
.steps{display:grid;grid-template-columns:repeat(2,1fr);gap:18px}
.steps article{
  position:relative;border:3px solid #111;padding:22px;background:#fff;box-shadow:5px 5px 0 #111
}
.step-no{
  display:inline-block;background:var(--yellow);border:2px solid #111;
  padding:3px 8px;font-size:11px;font-weight:900
}
.steps h3{font-size:17px;margin:14px 0 8px}
.steps p{font-size:12px;color:var(--muted);line-height:1.7}
.notice{
  margin-top:22px;border:3px solid #111;background:#fff3bf;padding:18px;box-shadow:5px 5px 0 #111
}
.notice strong{font-size:15px}
.notice p{margin:7px 0 0;font-size:12px;line-height:1.7}
footer{background:#111;color:#fff;text-align:center;padding:24px 0;font-size:12px}
.loading{grid-column:1/-1;text-align:center;padding:30px;color:#666}
@media(max-width:760px){
  .nav nav{display:none}
  .hero-inner{grid-template-columns:1fr;padding:42px 0}
  .hero h1{font-size:33px}
  .device-card{width:min(360px,92%);margin:0 auto}
  .download-grid,.steps{grid-template-columns:1fr}
  .download-card{transform:none!important}
}