:root {
  --bg: #f3f3f1; --surface: #fcfcfb; --border: #e2e1dc; --text: #0b0b0b; --muted: #52514e;
  --accent: #2a78d6; --accent-text: #fff; --critical: #d03b3b; --critical-bg: #fbeaea;
  color-scheme: light;
}
@media (prefers-color-scheme: dark) {
  :root:not([data-theme="light"]) {
    --bg: #111110; --surface: #1a1a19; --border: #2e2e2c; --text: #f0efec; --muted: #c3c2b7;
    --accent: #3987e5; --critical-bg: #3a1c1c; color-scheme: dark;
  }
}
* { box-sizing: border-box; }
body { margin: 0; min-height: 100vh; display: grid; place-items: center; padding: 16px;
  background: var(--bg); color: var(--text);
  font: 15px/1.5 system-ui, -apple-system, "Segoe UI", Roboto, sans-serif; }
.card { width: 100%; max-width: 380px; background: var(--surface); border: 1px solid var(--border);
  border-radius: 14px; padding: 28px; box-shadow: 0 8px 30px rgba(0,0,0,.06); }
.brand { display: flex; gap: 12px; align-items: center; margin-bottom: 22px; }
h1 { font-size: 18px; margin: 0; }
.brand p { margin: 0; color: var(--muted); font-size: 13px; }
label { display: block; font-size: 13px; font-weight: 600; margin: 14px 0 6px; }
input { width: 100%; padding: 10px 12px; font: inherit; color: inherit; background: var(--bg);
  border: 1px solid var(--border); border-radius: 8px; }
input:focus { outline: 2px solid var(--accent); outline-offset: 1px; border-color: transparent; }
button { width: 100%; margin-top: 22px; padding: 11px; font: inherit; font-weight: 600; cursor: pointer;
  background: var(--accent); color: var(--accent-text); border: 0; border-radius: 8px; }
button:hover { filter: brightness(1.08); }
.error { background: var(--critical-bg); color: var(--critical); border-radius: 8px; padding: 10px 12px;
  font-size: 14px; border-left: 3px solid var(--critical); }