:root {
  --bg: #1a1d21;
  --bg-2: #22262c;
  --border: #3d444d;
  --text: #e6edf3;
  --muted: #9aa4b0;
  --accent: #3d9ee0;
  --prompt: #7ec8e3;
  --ui: "Segoe UI", "PingFang SC", "Microsoft YaHei", "Noto Sans SC", sans-serif;
}
* { box-sizing: border-box; }
html, body { height: 100%; margin: 0; }
body {
  font-family: var(--ui);
  background: radial-gradient(1200px 600px at 50% -10%, #24313a, var(--bg));
  color: var(--text);
  display: flex;
  align-items: center;
  justify-content: center;
}
.card {
  width: min(420px, calc(100vw - 32px));
  background: var(--bg-2);
  border: 1px solid var(--border);
  border-radius: 14px;
  padding: 28px 28px 24px;
  box-shadow: 0 16px 48px rgba(0, 0, 0, 0.35);
}
.brand { display: flex; align-items: center; gap: 10px; margin-bottom: 18px; }
.brand .name { font-weight: 700; letter-spacing: 0.04em; }
.brand .sub { color: var(--muted); font-size: 12px; }
h1 { font-size: 22px; margin: 0 0 10px; }
.lead { color: var(--text); line-height: 1.55; margin: 0 0 20px; }
.hint { color: var(--muted); font-size: 13px; line-height: 1.5; margin: 16px 0 0; }
.google {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 10px;
  background: #fff;
  color: #3c4043;
  text-decoration: none;
  font-weight: 600;
  border-radius: 8px;
  padding: 10px 14px;
}
.google:hover { filter: brightness(0.97); }
a { color: var(--prompt); }