:root{
  --paper:#FFFFFF;
  --ink:#111111;
  --ink2:#3F3F46;
  --muted:#5C5C64;
  --faint:#8E8E96;
  --line:#E7E7EA;
  --line2:#F1F1F3;
  --radius:8px;
  --ease:cubic-bezier(.16,1,.3,1);
  --font:-apple-system,BlinkMacSystemFont,"Segoe UI","PingFang SC","Hiragino Sans GB","Microsoft YaHei",sans-serif;
  --mono:ui-monospace,SFMono-Regular,Menlo,Consolas,monospace;
}
*{box-sizing:border-box;margin:0;padding:0}
html{scroll-behavior:smooth}
body{font-family:var(--font);color:var(--ink);background:var(--paper);
  -webkit-font-smoothing:antialiased;text-rendering:optimizeLegibility;
  min-height:100vh;display:flex;flex-direction:column}
a{color:inherit;text-decoration:none}
::selection{background:#111;color:#fff}

.nav{border-bottom:1px solid var(--line);background:rgba(255,255,255,.92);
  backdrop-filter:blur(10px);position:sticky;top:0;z-index:50}
.nav-inner{max-width:1040px;margin:0 auto;padding:0 24px;height:60px;
  display:flex;align-items:center;justify-content:space-between}
.brand{display:flex;align-items:center;gap:9px;font-size:14px;font-weight:700;letter-spacing:.04em}
.brand img{width:24px;height:24px;border-radius:6px;object-fit:cover}
.nav-links{display:flex;gap:22px;font-size:13px;color:var(--muted)}
.nav-links a{position:relative;padding:3px 0;transition:color .2s}
.nav-links a::after{content:"";position:absolute;left:0;bottom:-2px;height:1px;width:0;
  background:var(--ink);transition:width .25s var(--ease)}
.nav-links a:hover{color:var(--ink)}
.nav-links a:hover::after{width:100%}

main{flex:1 0 auto;width:100%}

.hero{max-width:1040px;margin:0 auto;padding:64px 24px 56px;
  display:grid;grid-template-columns:1fr 260px;gap:56px;align-items:start}
.app-icon{width:76px;height:76px;border-radius:18px;overflow:hidden;
  border:1px solid var(--line);background:#fff}
.app-icon img{width:100%;height:100%;object-fit:cover;display:block}
.app-meta{margin-top:18px}
.app-meta h1{font-size:30px;letter-spacing:-.02em;font-weight:800}
.badges{margin-top:10px;display:flex;gap:8px;flex-wrap:wrap}
.badge{font-size:11.5px;padding:3px 9px;border-radius:999px;background:var(--ink);color:#fff}
.badge-line{background:transparent;color:var(--muted);border:1px solid var(--line)}
.desc{margin-top:18px;font-size:14px;line-height:1.95;color:var(--muted);max-width:520px}

.actions{margin-top:26px;display:flex;gap:10px;flex-wrap:wrap}
.btn-primary,.btn-ghost{display:inline-flex;align-items:center;gap:8px;height:46px;
  padding:0 20px;border-radius:var(--radius);font-size:14px;font-weight:600;
  border:1px solid var(--ink);cursor:pointer;font-family:var(--font);
  transition:background .2s,color .2s,transform .2s var(--ease)}
.btn-primary{background:var(--ink);color:#fff}
.btn-primary:hover{transform:translateY(-2px);background:#000}
.btn-ghost{background:transparent;color:var(--ink)}
.btn-ghost:hover{background:var(--ink);color:#fff;transform:translateY(-2px)}
.hint{margin-top:14px;font-size:12px;color:var(--faint);line-height:1.8}

.qr-card{border:1px solid var(--line);border-radius:12px;padding:18px;
  text-align:center;background:#fff}
.qr-box{width:100%;aspect-ratio:1/1;display:grid;place-items:center}
.qr-box img{width:100%;height:100%;display:block;image-rendering:pixelated}
.qr-title{margin-top:12px;font-size:13px;font-weight:600}
.qr-desc{margin-top:5px;font-size:11.5px;color:var(--faint);line-height:1.7}

.features{max-width:1040px;margin:0 auto;padding:0 24px 8px;
  display:grid;grid-template-columns:repeat(3,1fr);border-top:1px solid var(--line)}
.feature{padding:28px 22px 28px 0;border-bottom:1px solid var(--line)}
.feature + .feature{border-left:1px solid var(--line);padding-left:22px}
.feature .no{font-family:var(--mono);font-size:11px;color:var(--faint);letter-spacing:.12em}
.feature h3{margin-top:10px;font-size:15px;font-weight:700}
.feature p{margin-top:9px;font-size:12.5px;line-height:1.9;color:var(--muted)}

.steps{max-width:1040px;margin:0 auto;padding:56px 24px 72px}
.steps-head h2{margin-top:12px;font-size:24px;letter-spacing:-.01em}
.kicker{font-size:11px;letter-spacing:.2em;color:var(--faint)}
.steps ol{list-style:none;margin-top:24px;border-top:1px solid var(--line)}
.steps li{display:flex;gap:16px;align-items:baseline;padding:15px 0;
  border-bottom:1px solid var(--line2);font-size:13.5px;color:var(--ink2)}
.steps li span{font-family:var(--mono);font-size:11.5px;color:var(--faint);min-width:22px}

.footer{border-top:1px solid var(--line);background:var(--paper)}
.footer-inner{max-width:1040px;margin:0 auto;padding:26px 24px 34px;
  display:flex;justify-content:space-between;gap:18px;flex-wrap:wrap;
  font-size:12px;color:var(--faint);line-height:2}
.footer a{color:var(--muted);margin-right:16px;border-bottom:1px solid transparent;transition:.2s}
.footer a:hover{color:var(--ink);border-color:var(--ink)}
.copy{text-align:right}

.toast{position:fixed;left:50%;bottom:32px;transform:translate(-50%,16px);
  background:var(--ink);color:#fff;font-size:13px;padding:10px 18px;border-radius:999px;
  opacity:0;pointer-events:none;transition:.3s var(--ease);z-index:80}
.toast.show{opacity:1;transform:translate(-50%,0)}

body.wechat .qr-card{display:none}

@media (max-width:900px){
  .hero{grid-template-columns:1fr;gap:32px;padding:40px 20px 36px}
  .qr-card{display:none}
  .features{grid-template-columns:1fr;padding:0 20px}
  .feature,.feature + .feature{padding:22px 0;border-left:none}
  .steps{padding:40px 20px 56px}
  .footer-inner{padding:22px 20px 30px;flex-direction:column}
  .copy{text-align:left}
}
@media (max-width:520px){
  .app-meta h1{font-size:26px}
  .actions{flex-direction:column;align-items:stretch}
  .btn-primary,.btn-ghost{justify-content:center}
}