:root{--bg:#fff;--bg2:#f5f5f7;--ink:#1d1d1f;--mute:#6e6e73;--line:#e0e0e0;--blue:#0066cc;--blue-h:#0071e3;--card:#fff;--hero:#5b73ff}
@media (prefers-color-scheme:dark){:root{--bg:#000;--bg2:#161618;--ink:#f5f5f7;--mute:#a1a1a6;--line:#2c2c2e;--blue:#2997ff;--blue-h:#5ab0ff;--card:#1c1c1e}}
*{box-sizing:border-box}html{scroll-behavior:smooth}
body{margin:0;background:var(--bg);color:var(--ink);font:17px/1.55 -apple-system,BlinkMacSystemFont,"SF Pro Text","Segoe UI",system-ui,sans-serif;-webkit-font-smoothing:antialiased}
a{color:var(--blue);text-decoration:none}a:hover{text-decoration:underline}
img{max-width:100%;height:auto}
.wrap{max-width:980px;margin:0 auto;padding:0 20px}
nav{position:sticky;top:0;z-index:5;background:color-mix(in srgb,var(--bg) 80%,transparent);backdrop-filter:saturate(180%) blur(16px);border-bottom:1px solid var(--line)}
nav .wrap{display:flex;align-items:center;gap:22px;height:48px;font-size:14px}
nav .brand{font-weight:600;color:var(--ink);display:flex;align-items:center;gap:8px;margin-right:auto}
nav .brand img{width:26px;height:26px}
nav a.l{color:var(--ink);opacity:.8}nav a.l:hover{opacity:1;text-decoration:none}
.btn{display:inline-block;background:var(--blue);color:#fff!important;padding:11px 22px;border-radius:980px;font-size:17px;font-weight:600;border:0}
.btn:hover{background:var(--blue-h);text-decoration:none}
.btn.sm{padding:6px 14px;font-size:14px}
.btn.ghost{background:transparent;color:var(--blue)!important;border:1px solid var(--blue)}
.btn.off{background:var(--mute);cursor:default;opacity:.7}
.hero{background:var(--bg2);text-align:center;padding:56px 0 0;overflow:hidden}
.hero h1{font-size:clamp(36px,7vw,64px);line-height:1.05;letter-spacing:-.02em;margin:.2em 0 .25em}
.hero p.lead{font-size:clamp(19px,3vw,26px);color:var(--mute);max-width:640px;margin:0 auto 1.4em}
.hero .cta{display:flex;gap:14px;justify-content:center;flex-wrap:wrap}
.hero img{display:block;margin:28px auto 0;width:min(440px,78vw)}
.note{font-size:13px;color:var(--mute);margin-top:14px}
section{padding:72px 0}section.alt{background:var(--bg2)}
h2{font-size:clamp(28px,4.5vw,40px);line-height:1.1;letter-spacing:-.015em;margin:0 0 .5em;text-align:center}
.sub{text-align:center;color:var(--mute);font-size:21px;max-width:660px;margin:0 auto 2.2em}
.grid{display:grid;gap:18px;grid-template-columns:repeat(auto-fit,minmax(260px,1fr))}
.card{background:var(--card);border:1px solid var(--line);border-radius:18px;padding:26px}
.card h3{margin:.1em 0 .3em;font-size:21px}.card p{margin:0;color:var(--mute)}
.card .ic{font-size:30px;line-height:1}
.rules{columns:2 280px;column-gap:34px;max-width:760px;margin:0 auto;padding:0;list-style:none}
.rules li{break-inside:avoid;padding:9px 0;border-bottom:1px solid var(--line)}.rules b{display:block}.rules span{color:var(--mute);font-size:15px}
.steps{counter-reset:s;display:grid;gap:18px;grid-template-columns:repeat(auto-fit,minmax(240px,1fr))}
.steps div{background:var(--card);border:1px solid var(--line);border-radius:18px;padding:26px}
.steps div:before{counter-increment:s;content:counter(s);display:grid;place-items:center;width:34px;height:34px;border-radius:50%;background:var(--blue);color:#fff;font-weight:700;margin-bottom:12px}
.steps h3{margin:0 0 .3em;font-size:19px}.steps p{margin:0;color:var(--mute);font-size:16px}
code,kbd{font:14px ui-monospace,SFMono-Regular,Menlo,monospace;background:var(--bg2);border:1px solid var(--line);border-radius:6px;padding:1px 6px}
article{max-width:720px;margin:0 auto;padding:56px 20px 72px}
article h1{font-size:clamp(32px,5vw,48px);letter-spacing:-.02em;line-height:1.1;margin:0 0 .4em}
article h2{text-align:left;font-size:26px;margin:1.6em 0 .4em}
article p,article li{color:var(--ink)}article .mute{color:var(--mute)}
details{border-bottom:1px solid var(--line);padding:14px 0}summary{cursor:pointer;font-weight:600}
details p{color:var(--mute);margin:.6em 0 0}
.dl{background:var(--bg2);border-radius:22px;padding:32px;text-align:center;margin:26px 0}
footer{border-top:1px solid var(--line);padding:30px 0 44px;font-size:13px;color:var(--mute)}
footer .wrap{display:flex;flex-wrap:wrap;gap:8px 22px}footer .r{margin-left:auto}
.ver{margin:.6em 0 1.6em;padding-left:1em;border-left:3px solid var(--blue)}.ver h2{margin:0}