:root{--bg:#f2f5f9;--card:#fff;--ink:#14202e;--mute:#5d6b7c;--line:#d9e0e8;--acc:#1f5fa8}
@media (prefers-color-scheme:dark){:root{--bg:#0f1722;--card:#17212f;--ink:#e6edf5;--mute:#93a1b2;--line:#2a3646;--acc:#5aa0ec}}
*{box-sizing:border-box}body{margin:0;min-height:100vh;display:grid;place-items:center;background:var(--bg);color:var(--ink);font:16px/1.4 system-ui,-apple-system,"Segoe UI",Roboto,sans-serif;padding:16px}
.box{width:100%;max-width:360px;background:var(--card);border:1px solid var(--line);border-radius:14px;padding:24px}
h1{margin:0;font-size:22px}.sub{color:var(--mute);margin:4px 0 18px;font-size:14px}
label{display:block;font-size:13px;color:var(--mute);margin:12px 0}input{display:block;width:100%;margin-top:6px;padding:12px;border:1px solid var(--line);border-radius:10px;background:transparent;color:var(--ink);font-size:16px}
button{width:100%;margin-top:14px;padding:13px;border:0;border-radius:10px;background:var(--acc);color:#fff;font-size:16px;font-weight:600}.err{color:#c0392b;font-size:14px}