:root {
  --text: #000;
  --muted: #707579;
  --accent: #2481cc;
  --accent-hover: #1a8ad5;
  --bg: #eef1f4;
  --card: #fff;
  --line: #dfe1e5;
  --warn: #8a5a00;
  --warn-bg: #fff6e0;
  --error: #c0392b;
  --ok: #2e7d32;
}
@media (prefers-color-scheme: dark) {
  :root {
    --text: #fff;
    --muted: #a0a4a8;
    --accent: #1c93e3;
    --accent-hover: #2a9ef1;
    --bg: #0f1012;
    --card: #1e1e1e;
    --line: #333;
    --warn: #ffd27a;
    --warn-bg: #3a2f14;
    --error: #ff7a6b;
    --ok: #7bd389;
  }
}
* { box-sizing: border-box; }
[hidden] { display: none !important; }
html, body { margin: 0; min-height: 100%; }
body {
  font-family: Roboto, -apple-system, BlinkMacSystemFont, "Segoe UI", "Helvetica Neue", Arial, sans-serif;
  color: var(--text);
  background: var(--bg);
  -webkit-text-size-adjust: 100%;
  display: flex;
  justify-content: center;
  padding: 24px 16px;
}
.card {
  width: 100%;
  max-width: 420px;
  background: var(--card);
  border-radius: 14px;
  padding: 24px 20px;
  box-shadow: 0 2px 12px rgba(0, 0, 0, .08);
  line-height: 1.45;
}
h1 { font-size: 22px; margin: 0 0 16px; }
p { margin: 0 0 14px; }
.muted { color: var(--muted); }
.small { font-size: 14px; }
.warn { background: var(--warn-bg); color: var(--warn); border-radius: 10px; padding: 10px 12px; font-size: 15px; }
.error { color: var(--error); font-size: 15px; }
.ok { color: var(--ok); font-size: 20px; font-weight: 600; }
label { display: block; font-weight: 500; margin: 4px 0 6px; }
input {
  width: 100%;
  font-size: 18px;
  padding: 12px;
  border: 1px solid var(--line);
  border-radius: 10px;
  background: transparent;
  color: var(--text);
  margin-bottom: 12px;
}
input:focus { outline: 2px solid var(--accent); border-color: transparent; }
button, .button {
  display: block;
  width: 100%;
  font: inherit;
  font-size: 17px;
  font-weight: 600;
  text-align: center;
  text-decoration: none;
  border: 0;
  border-radius: 10px;
  padding: 14px;
  margin: 0 0 12px;
  cursor: pointer;
}
.primary { background: var(--accent); color: #fff; }
.primary:hover { background: var(--accent-hover); }
.secondary { background: transparent; color: var(--accent); border: 1px solid var(--line); }
.spinner {
  width: 36px;
  height: 36px;
  margin: 8px auto 16px;
  border: 3px solid var(--line);
  border-top-color: var(--accent);
  border-radius: 50%;
  animation: spin .9s linear infinite;
}
#waiting p { text-align: center; }
@keyframes spin { to { transform: rotate(360deg); } }