:root { color-scheme: light dark; --bg: #faf5f5; --fg: #2a1616; --muted: #7a6262; --card: #fff; --line: #e6d5d5; --accent: #8b1a1a; --on-accent: #fff; --error: #b42318; }
@media (prefers-color-scheme: dark) { :root { --bg: #1a1111; --fg: #f5ecec; --muted: #b59d9d; --card: #251818; --line: #4a2e2e; --accent: #c53030; --on-accent: #fff; --error: #fda29b; } }
* { box-sizing: border-box; }
body { margin: 0; min-height: 100vh; display: grid; place-items: center; background: var(--bg); color: var(--fg); font: 16px/1.4 system-ui, sans-serif; }
main { width: min(92vw, 28rem); padding: 1.5rem; background: var(--card); border: 1px solid var(--line); border-radius: 12px; }
h1 { margin: 0 0 .5rem; font-size: 1.2rem; }
p { margin: 0 0 1rem; color: var(--muted); }
form { display: flex; gap: .5rem; }
input, button { font: inherit; padding: .6rem .8rem; border-radius: 8px; border: 1px solid var(--line); background: var(--bg); color: var(--fg); }
input { flex: 1; min-width: 0; letter-spacing: .3em; text-align: center; text-transform: uppercase; }
input:focus { outline: 2px solid var(--accent); outline-offset: 1px; }
form button { background: var(--accent); color: var(--on-accent); border-color: var(--accent); cursor: pointer; }
.msg { min-height: 1.4em; margin: .75rem 0 0; color: var(--error); }
[hidden] { display: none !important; }