:root {
  --bg: #fff8f3;
  --card: #ffffff;
  --ink: #1f1b16;
  --muted: #50453a;
  --primary: #3d4ab8;
  --on-primary: #ffffff;
  --line: #d4c4b5;
}
@media (prefers-color-scheme: dark) {
  :root {
    --bg: #17130e;
    --card: #241f1a;
    --ink: #ebe1d9;
    --muted: #d4c4b5;
    --primary: #bcc2ff;
    --on-primary: #11208f;
    --line: #50453a;
  }
}
* { box-sizing: border-box; }
body {
  margin: 0;
  min-height: 100vh;
  display: grid;
  place-items: center;
  padding: 16px;
  background: var(--bg);
  color: var(--ink);
  font: 16px/1.5 system-ui, -apple-system, "Segoe UI", Roboto, sans-serif;
}
.card {
  width: 100%;
  max-width: 440px;
  background: var(--card);
  border: 1px solid var(--line);
  border-radius: 24px;
  padding: 32px 24px;
  text-align: center;
}
.card.left { text-align: left; }
.card.wide { max-width: 720px; margin: 24px 0; }
h3 { font-size: .98rem; margin: 16px 0 4px; }
.small-top { font-size: .85rem; margin-top: 0; }
.todo { background: #ffe08a; color: #3a2b00; padding: 0 4px; border-radius: 4px; }
h1 { font-size: 1.5rem; line-height: 1.25; margin: 12px 0; }
h2 { font-size: 1.05rem; margin: 20px 0 6px; }
p, li { color: var(--muted); }
.code-label { margin: 20px 0 0; font-size: .8rem; letter-spacing: .08em; text-transform: uppercase; }
.code { font: 700 2.2rem/1.2 ui-monospace, "Roboto Mono", monospace; letter-spacing: .25em; color: var(--ink); margin: 4px 0 16px; }
.hint { font-size: .9rem; }
.button {
  display: inline-block;
  margin-top: 12px;
  padding: 12px 22px;
  border-radius: 999px;
  background: var(--primary);
  color: var(--on-primary);
  text-decoration: none;
  font-weight: 600;
}
.small { font-size: .85rem; margin-top: 24px; }
a { color: var(--primary); }