:root {
  color-scheme: light dark;
  --bg: #f6f7f9; --surface: #fff; --border: #d9dde4; --text: #16191d;
  --muted: #667085; --accent: #2f6df6; --danger: #d3453a;
}
@media (prefers-color-scheme: dark) {
  :root { --bg: #16181d; --surface: #1e2128; --border: #343945; --text: #e6e8ec; --muted: #98a0af; --accent: #5b8cff; --danger: #f0736a; }
}
* { box-sizing: border-box; }
body {
  margin: 0; min-height: 100dvh; display: grid; place-items: center; padding: 20px;
  background: var(--bg); color: var(--text);
  font: 14px/1.5 -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Arial, sans-serif;
  -webkit-text-size-adjust: 100%;
}
.card {
  width: min(360px, 100%); padding: 26px 22px; text-align: center;
  background: var(--surface); border: 1px solid var(--border); border-radius: 18px;
  box-shadow: 0 8px 30px rgba(16, 24, 40, .1);
}
.logo { width: 34px; height: 34px; color: var(--accent); }
h1 { margin: 10px 0 2px; font-size: 19px; letter-spacing: -.01em; }
.sub { margin: 0 0 18px; color: var(--muted); font-size: 13px; }
input {
  width: 100%; height: 44px; padding: 0 12px; margin-bottom: 10px;
  border: 1px solid var(--border); border-radius: 12px;
  background: var(--bg); color: var(--text); font-size: 16px;
}
input:focus { outline: 2px solid var(--accent); outline-offset: 1px; border-color: transparent; }
button {
  width: 100%; height: 44px; border: 0; border-radius: 12px;
  background: var(--accent); color: #fff; font-size: 15px; font-weight: 600; cursor: pointer;
}
button:hover { filter: brightness(1.07); }
button:disabled { opacity: .6; cursor: default; }
.err { color: var(--danger); font-size: 13px; margin: 12px 0 0; }
.hint { color: var(--muted); font-size: 12px; margin: 16px 0 0; }