:root {
  --bg-top: #d3e3ff; --bg: #f2f6ff; --card: #ffffff; --text: #0f1b2d; --muted: #44536b;
  --primary: #1652b8; --border: #d3dceb; --danger: #c62828; --danger-bg: #fde8e8; --ok: #2e7d32;
}
@media (prefers-color-scheme: dark) {
  :root:not([data-theme="light"]) {
    --bg-top: #14305e; --bg: #0a1322; --card: #111c2f; --text: #e2e8f3; --muted: #b8c4d8;
    --primary: #a9c8ff; --border: #2c3b57; --danger: #ff8a80; --danger-bg: #3a1c1c; --ok: #81c784;
  }
}
* { box-sizing: border-box; }
body {
  margin: 0; color: var(--text); background: linear-gradient(180deg, var(--bg-top), var(--bg) 320px) no-repeat, var(--bg);
  font: 16px/1.6 system-ui, -apple-system, "Segoe UI", Roboto, sans-serif;
}
main { max-width: 760px; margin: 0 auto; padding: 32px 16px 64px; }
header { display: flex; align-items: center; gap: 12px; margin-bottom: 8px; }
header img { width: 44px; height: 44px; }
h1 { font-size: 1.6rem; margin: 0; }
h2 { font-size: 1.2rem; margin: 28px 0 8px; }
.card { background: var(--card); border: 1px solid var(--border); border-radius: 18px; padding: 20px 22px; margin-top: 18px; }
.lang { display: flex; gap: 8px; margin: 12px 0 4px; }
.lang a { padding: 6px 14px; border-radius: 999px; border: 1px solid var(--border); color: var(--primary); text-decoration: none; background: var(--card); }
.muted { color: var(--muted); font-size: .92rem; }
a { color: var(--primary); }
label { display: block; font-weight: 600; margin: 14px 0 6px; }
input[type=text], input[type=password] {
  width: 100%; padding: 12px 14px; border-radius: 12px; border: 1px solid var(--border);
  background: var(--bg); color: var(--text); font-size: 1rem;
}
.check { display: flex; gap: 10px; align-items: flex-start; margin-top: 16px; font-weight: 400; }
button {
  margin-top: 18px; width: 100%; padding: 13px; border: 0; border-radius: 999px; font-size: 1rem; font-weight: 600;
  background: var(--danger); color: #fff; cursor: pointer;
}
button:disabled { opacity: .45; cursor: not-allowed; }
.warn { background: var(--danger-bg); border-radius: 14px; padding: 14px 16px; margin-top: 14px; }
#result { margin-top: 16px; font-weight: 600; min-height: 1.5em; }
#result.ok { color: var(--ok); } #result.err { color: var(--danger); }
footer { margin-top: 40px; text-align: center; }