:root{
  --bg:#fbfaf7; --surface:#ffffff; --text:#1d1f1e; --muted:#5f6663; --line:#e4e2dc;
  --accent:#1f6f54; --accent-soft:#e3f0ea; --star:#e2a400;
  --radius:14px; --max:760px;
  color-scheme: light;
}
@media (prefers-color-scheme: dark){
  :root:not([data-theme="light"]){
    --bg:#141615; --surface:#1c1f1e; --text:#eceeed; --muted:#a3aaa6; --line:#2d3230;
    --accent:#5cc79d; --accent-soft:#1e3229; --star:#f2c443;
    color-scheme: dark;
  }
}
:root[data-theme="dark"]{
  --bg:#141615; --surface:#1c1f1e; --text:#eceeed; --muted:#a3aaa6; --line:#2d3230;
  --accent:#5cc79d; --accent-soft:#1e3229; --star:#f2c443;
  color-scheme: dark;
}
*{box-sizing:border-box}
html{-webkit-text-size-adjust:100%}
body{margin:0;background:var(--bg);color:var(--text);
  font:16px/1.75 -apple-system,BlinkMacSystemFont,"Segoe UI","PingFang TC","Noto Sans TC","Microsoft JhengHei",sans-serif}
a{color:var(--accent)}
.wrap{max-width:var(--max);margin:0 auto;padding:0 16px}
header.top{border-bottom:1px solid var(--line);background:var(--surface)}
header.top .wrap{display:flex;align-items:center;justify-content:space-between;gap:12px;min-height:60px;flex-wrap:wrap}
.logo{display:flex;align-items:center;gap:10px;font-weight:700;text-decoration:none;color:var(--text);letter-spacing:.01em}
.logo svg{flex:none}
.logo small{font-weight:500;color:var(--muted)}
nav.links{display:flex;gap:16px;font-size:15px}
nav.links a{color:var(--muted);text-decoration:none}
nav.links a:hover,nav.links a[aria-current]{color:var(--text)}
main{padding:40px 0 64px}
h1{font-size:30px;line-height:1.3;margin:0 0 8px}
h2{font-size:21px;line-height:1.4;margin:40px 0 8px}
h3{font-size:17px;margin:24px 0 4px}
p,li{color:var(--text)}
.muted{color:var(--muted)}
.lang{display:inline-flex;gap:8px;margin:8px 0 24px;font-size:14px}
.lang a{padding:4px 12px;border:1px solid var(--line);border-radius:999px;text-decoration:none;color:var(--muted);background:var(--surface)}
.card{background:var(--surface);border:1px solid var(--line);border-radius:var(--radius);padding:20px 22px;margin:16px 0}
.mail{display:inline-block;font-weight:600;font-size:18px;padding:10px 18px;border-radius:10px;background:var(--accent-soft);text-decoration:none;word-break:break-all}
hr.split{border:0;border-top:1px solid var(--line);margin:56px 0 0}
footer{border-top:1px solid var(--line);padding:24px 0;font-size:14px;color:var(--muted)}
footer .wrap{display:flex;gap:16px;flex-wrap:wrap;justify-content:space-between}
footer a{color:var(--muted)}
details{border-bottom:1px solid var(--line);padding:12px 0}
summary{cursor:pointer;font-weight:600}
details p{margin:8px 0 0}
/* home */
.hero{padding:32px 0 8px}
.hero .big{font-size:44px;line-height:1.15;font-weight:800;margin:0 0 12px;letter-spacing:-.01em}
.hero .big em{font-style:normal;color:var(--accent)}
.hero p.lead{font-size:19px;color:var(--muted);max-width:34em;margin:0}
.badge{display:inline-block;font-size:13px;font-weight:600;color:var(--accent);background:var(--accent-soft);padding:4px 12px;border-radius:999px;margin-bottom:16px}
.grid{display:grid;grid-template-columns:repeat(3,1fr);gap:14px;margin:32px 0}
.grid .card{margin:0}
.grid h3{margin:0 0 4px}
.grid p{margin:0;color:var(--muted);font-size:15px}
.demo{display:flex;gap:10px;margin:32px 0 8px}
.demo div{flex:1;aspect-ratio:1;border-radius:12px;background:linear-gradient(135deg,#c9d7cf,#8fb3a2);position:relative;opacity:.45}
.demo div.best{opacity:1;outline:3px solid var(--accent);outline-offset:2px}
.demo div.best::after{content:"★";position:absolute;top:8px;right:10px;color:var(--star);font-size:20px;text-shadow:0 1px 2px rgba(0,0,0,.3)}
@media (max-width:640px){
  .grid{grid-template-columns:1fr}
  .hero .big{font-size:34px}
  h1{font-size:25px}
}
/* 購買、領取序號、管理裝置 */
.btn{display:inline-flex;align-items:center;justify-content:center;gap:8px;font:inherit;font-weight:700;font-size:18px;padding:14px 22px;border-radius:12px;border:0;background:var(--accent);color:#fff;text-decoration:none;cursor:pointer;width:100%}
.btn:disabled{opacity:.5;cursor:default}
.btn.ghost{background:var(--surface);color:var(--text);border:1px solid var(--line);font-weight:600;font-size:15px;padding:8px 14px;width:auto}
.small-link{display:block;text-align:center;margin-top:14px;font-size:14px;color:var(--muted)}
.field{width:100%;font:inherit;padding:12px 14px;border:1px solid var(--line);border-radius:10px;background:var(--bg);color:var(--text);margin:6px 0 14px}
.price{font-size:36px;font-weight:800;margin:4px 0 0}
.ticks{list-style:none;padding:0;margin:16px 0 20px}
.ticks li{padding-left:26px;position:relative;margin:4px 0}
.ticks li::before{content:"✓";position:absolute;left:0;color:var(--accent);font-weight:700}
.keybox{font:600 22px/1.4 ui-monospace,SFMono-Regular,Menlo,Consolas,monospace;letter-spacing:.04em;padding:16px;border-radius:12px;background:var(--accent-soft);text-align:center;word-break:break-all;margin:12px 0}
.dev{display:flex;align-items:center;justify-content:space-between;gap:12px;border-top:1px solid var(--line);padding:12px 0}
.dev:first-of-type{border-top:0}
.note{font-size:14px;color:var(--muted)}
.spin{display:inline-block;width:18px;height:18px;border:3px solid var(--accent-soft);border-top-color:var(--accent);border-radius:50%;animation:sp 1s linear infinite;vertical-align:-3px}
@keyframes sp{to{transform:rotate(360deg)}}