:root{--bg:#f4f2ed;--surface:#fff;--ink:#18212f;--muted:#5b6676;--line:#e1ddd3;--accent:#2457c5;--accent-ink:#fff}
@media (prefers-color-scheme:dark){:root{--bg:#10151d;--surface:#19212c;--ink:#e8ecf2;--muted:#9aa5b4;--line:#2a3442;--accent:#8cb0f2;--accent-ink:#0d1726;color-scheme:dark}}
*{box-sizing:border-box}
html,body{margin:0;height:100%}
body{background:var(--bg);color:var(--ink);font:16px/1.5 system-ui,-apple-system,"Segoe UI",Roboto,Arial,sans-serif;display:grid;place-items:center;padding:16px}
.gate{background:var(--surface);border:1px solid var(--line);border-radius:22px;padding:32px 28px;max-width:420px;width:100%;text-align:center;display:grid;gap:14px;justify-items:center}
.mark{width:72px;height:72px}
h1{margin:0;font-size:26px;letter-spacing:-.01em}
p{margin:0}
.lead{color:var(--muted)}
.muted{color:var(--muted)} .small{font-size:13px}
.btn{display:inline-block;border:0;border-radius:14px;background:var(--accent);color:var(--accent-ink);font:inherit;font-weight:700;padding:13px 22px;cursor:pointer;text-decoration:none}
.btn:focus-visible{outline:3px solid var(--ink);outline-offset:2px}
#step-code{display:grid;gap:12px;justify-items:center}
.code{font:800 34px/1 ui-monospace,SFMono-Regular,Menlo,monospace;letter-spacing:.08em;padding:14px 18px;border:2px dashed var(--line);border-radius:14px}
.msg{color:#c8162f;min-height:1.5em}
.foot{margin-top:6px}
a{color:var(--accent)}
[hidden]{display:none!important}