:root {
  --bg: #fff8f0;
  --card: #ffffff;
  --text: #3b2a1f;
  --muted: #6e5646;
  --accent: #e07a3f;
  --on-accent: #ffffff;
  --error: #b3261e;
  color-scheme: light dark;
}

@media (prefers-color-scheme: dark) {
  :root {
    --bg: #1f1813;
    --card: #2b221b;
    --text: #f5e9de;
    --muted: #c9b3a2;
    --accent: #f0955e;
    --on-accent: #1f1813;
    --error: #f2b8b5;
  }
}

* { box-sizing: border-box; }

body {
  margin: 0;
  min-height: 100vh;
  display: flex;
  align-items: center;
  justify-content: center;
  padding: 16px;
  background: var(--bg);
  color: var(--text);
  font-family: -apple-system, BlinkMacSystemFont, "PingFang TC", "Hiragino Sans", sans-serif;
  line-height: 1.5;
}

.card {
  width: 100%;
  max-width: 420px;
  padding: 32px 24px;
  border-radius: 20px;
  background: var(--card);
  text-align: center;
}

h1 { margin: 0 0 8px; font-size: 1.6rem; }
.muted { color: var(--muted); margin: 4px 0; }
.error { color: var(--error); }

.code {
  margin: 4px 0 12px;
  font-size: 2rem;
  font-weight: 700;
  letter-spacing: 0.3em;
  font-variant-numeric: tabular-nums;
  overflow-wrap: anywhere;
}

button, .store {
  display: inline-block;
  min-height: 44px;
  padding: 10px 20px;
  border-radius: 999px;
  font: inherit;
  font-weight: 600;
  text-decoration: none;
  cursor: pointer;
}

button {
  border: 1px solid var(--accent);
  background: transparent;
  color: var(--accent);
}

.store {
  margin-top: 20px;
  border: none;
  background: var(--accent);
  color: var(--on-accent);
}

.steps {
  margin: 24px 0 0;
  padding-left: 1.4em;
  text-align: left;
  color: var(--muted);
}