:root { --bg: #f6f5ef; --card: #fff; --ink: #0d2523; --abyss: #012624; --gold: #f3d300; --line: #d9dfdc; }
@media (prefers-color-scheme: dark) { :root { --bg: #0a1a19; --card: #11302d; --ink: #eef3f1; --line: #244743; } }
* { box-sizing: border-box; }
body { margin: 0; min-height: 100vh; display: grid; place-items: center; background: var(--bg); color: var(--ink);
  font-family: system-ui, "Assistant", sans-serif; padding: 16px; }
.box { background: var(--card); border: 1px solid var(--line); border-radius: 14px; padding: 24px; width: min(380px, 100%); }
h1 { margin: 0 0 16px; color: var(--abyss); font-size: 1.5rem; }
@media (prefers-color-scheme: dark) { h1 { color: var(--gold); } }
label { display: block; font-weight: 700; }
input { display: block; width: 100%; margin-top: 6px; padding: 10px; font: inherit; border: 1px solid var(--line);
  border-radius: 8px; background: var(--card); color: var(--ink); }
button { margin-top: 16px; width: 100%; padding: 10px; font: inherit; font-weight: 800; border: 0; border-radius: 8px;
  background: var(--abyss); color: var(--gold); cursor: pointer; }
.err { color: #c0392b; font-weight: 700; }