:root {
  --bg: #f2f2f7;
  --card: #ffffff;
  --text: #1c1c1e;
  --secondary: #6e6e73;
  --accent: #1d7a5e;
  --accent-text: #ffffff;
  --chip: #e5e5ea;
}
@media (prefers-color-scheme: dark) {
  :root {
    --bg: #000000;
    --card: #1c1c1e;
    --text: #f2f2f7;
    --secondary: #98989f;
    --accent: #4fc799;
    --accent-text: #00140d;
    --chip: #2c2c2e;
  }
}
* { box-sizing: border-box; }
body {
  margin: 0;
  background: var(--bg);
  color: var(--text);
  font: 17px/1.45 -apple-system, BlinkMacSystemFont, "SF Pro Text", system-ui, sans-serif;
  -webkit-font-smoothing: antialiased;
}
main { max-width: 460px; margin: 0 auto; padding: 56px 16px 40px; }
.brand { font-weight: 700; color: var(--accent); margin: 0 0 24px; letter-spacing: -0.01em; }
h1 { font-size: 32px; line-height: 1.15; letter-spacing: -0.02em; margin: 0 0 12px; }
.lede { color: var(--secondary); margin: 0 0 28px; }
.card { background: var(--card); border-radius: 22px; padding: 20px; }
.button, button {
  display: block; width: 100%; text-align: center; text-decoration: none;
  font: inherit; font-weight: 600; border: 0; border-radius: 14px; padding: 15px; cursor: pointer;
}
.button { background: var(--accent); color: var(--accent-text); }
.secondary { background: var(--chip); color: var(--text); }
.hint { color: var(--secondary); font-size: 15px; margin: 18px 0 8px; }
.code {
  font: 600 28px/1.2 ui-monospace, "SF Mono", Menlo, monospace; letter-spacing: 0.08em;
  text-align: center; margin: 4px 0 14px; word-break: break-all;
}
.small { color: var(--secondary); font-size: 13px; margin-top: 20px; }