:root{color-scheme:light dark;--fg:#111;--bg:#fff;--mut:#666;--acc:#2563eb;--bd:#d4d4d8}
@media (prefers-color-scheme:dark){:root{--fg:#eee;--bg:#111;--mut:#9a9a9a;--bd:#3f3f46}}
*{box-sizing:border-box}body{margin:0;font:17px/1.4 -apple-system,system-ui,sans-serif;background:var(--bg);color:var(--fg)}
main{max-width:460px;margin:0 auto;padding:28px 20px calc(28px + env(safe-area-inset-bottom))}
h1{font-size:24px;margin:0 0 8px}label{display:block;font-weight:600;margin:16px 0 6px}
.row{display:flex;gap:8px}input{flex:1;min-width:0;font-size:18px;padding:12px;border:1px solid var(--bd);border-radius:10px;background:transparent;color:inherit}
button{font:inherit;border-radius:10px;padding:12px 14px;border:1px solid var(--bd);background:transparent;color:inherit}
.primary{background:var(--acc);border-color:var(--acc);color:#fff;font-weight:600}.wide{width:100%;margin-top:12px}
button:disabled{opacity:.5}.muted{color:var(--mut)}.small{font-size:14px}.err{color:#dc2626}
.code{font:700 40px/1 ui-monospace,Menlo,monospace;letter-spacing:.2em;text-align:center;margin:16px 0}.foot{margin-top:32px}