:root { --bg: #f4f6fa; --panel: #fff; --ink: #1b2330; --muted: #5d6b80; --line: #e2e7ef; --brand: #2f6fdf; }
@media (prefers-color-scheme: dark) {
  :root { --bg: #0f141b; --panel: #161d27; --ink: #e6ebf2; --muted: #9aa7b8; --line: #263142; --brand: #5b8ff0; }
}
* { box-sizing: border-box; }
body { margin: 0; min-height: 100vh; display: grid; place-items: center; background: var(--bg); color: var(--ink);
  font: 15px/1.5 system-ui, -apple-system, "Segoe UI", Roboto, Arial, sans-serif; padding: 16px; }
.card { width: min(380px, 100%); background: var(--panel); border: 1px solid var(--line); border-radius: 14px; padding: 28px; }
.logo { font-size: 30px; color: var(--brand); }
h1 { margin: 4px 0 0; font-size: 20px; }
.sub { margin: 0 0 18px; color: var(--muted); font-size: 13.5px; }
label { display: block; font-size: 13.5px; font-weight: 600; margin-bottom: 12px; }
input { display: block; width: 100%; margin-top: 4px; padding: 9px 11px; border: 1px solid var(--line); border-radius: 8px;
  font: inherit; background: var(--panel); color: var(--ink); }
button { width: 100%; padding: 10px; border: 0; border-radius: 8px; background: var(--brand); color: #fff; font: inherit; font-weight: 600; cursor: pointer; }
.err { color: #c03030; font-size: 14px; }