:root{--bg:#f5f5f7;--card:#fff;--ink:#1d1d1f;--muted:#6e6e73;--line:#d2d2d7;--accent:#0071e3;--bad:#d70015}
@media (prefers-color-scheme: dark){:root{--bg:#000;--card:#1c1c1e;--ink:#f5f5f7;--muted:#98989d;--line:#3a3a3c;--accent:#0a84ff;--bad:#ff453a}}
*{box-sizing:border-box}
body{margin:0;min-height:100vh;display:grid;place-items:center;padding:20px;background:var(--bg);color:var(--ink);font:15px/1.4 -apple-system,BlinkMacSystemFont,"SF Pro Text","Segoe UI",system-ui,sans-serif}
form{width:100%;max-width:360px;background:var(--card);border-radius:22px;padding:30px 26px;box-shadow:0 10px 30px rgba(0,0,0,.08)}
h1{margin:0 0 4px;font-size:22px;font-weight:600;letter-spacing:-.02em}
p{margin:0 0 22px;color:var(--muted);font-size:13.5px}
label{display:block;font-size:13px;font-weight:500;margin:14px 0 6px}
input{width:100%;font:inherit;font-size:16px;color:var(--ink);background:transparent;border:1px solid var(--line);border-radius:12px;padding:11px 13px;outline:none}
input:focus{border-color:var(--accent);box-shadow:0 0 0 3px color-mix(in srgb,var(--accent) 22%,transparent)}
#code{letter-spacing:.3em;font-variant-numeric:tabular-nums}
button{width:100%;margin-top:22px;font:inherit;font-weight:600;color:#fff;background:var(--accent);border:0;border-radius:12px;padding:12px;cursor:pointer}
button:disabled{opacity:.6;cursor:default}
#msg{min-height:20px;margin:12px 0 0;color:var(--bad);font-size:13px}