:root {
  --color-bg: #f5f5f5;
  --color-card: #ffffff;
  --color-text: #202020;
  --color-muted: #6b6b6b;
  --color-primary: #202020;
  --color-on-primary: #ffffff;
  --color-border: #e2e2e2;
  --radius: 8px;
}

@media (prefers-color-scheme: dark) {
  :root {
    --color-bg: #121212;
    --color-card: #1e1e1e;
    --color-text: #f2f2f2;
    --color-muted: #a0a0a0;
    --color-primary: #ffffff;
    --color-on-primary: #202020;
    --color-border: #333333;
  }
}

* { box-sizing: border-box; }

body {
  margin: 0;
  min-height: 100vh;
  display: flex;
  align-items: center;
  justify-content: center;
  padding: 16px;
  background: var(--color-bg);
  color: var(--color-text);
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Helvetica, Arial, sans-serif;
}

.card {
  width: 100%;
  max-width: 400px;
  padding: 32px 24px;
  background: var(--color-card);
  border-radius: 16px;
  text-align: center;
}

h1 { font-size: 24px; margin: 0 0 8px; }
p { color: var(--color-muted); line-height: 1.5; margin: 0 0 24px; }

.reference {
  margin: 0 0 24px;
  padding: 16px;
  border: 1px solid var(--color-border);
  border-radius: var(--radius);
}
.reference span { display: block; font-size: 13px; color: var(--color-muted); }
.reference strong { font-size: 22px; letter-spacing: 1px; }

.button {
  display: block;
  padding: 14px 24px;
  margin: 0 0 12px;
  border-radius: var(--radius);
  font-weight: 600;
  text-decoration: none;
  background: var(--color-primary);
  color: var(--color-on-primary);
}
.button.secondary {
  background: transparent;
  color: var(--color-text);
  border: 1px solid var(--color-border);
}

[hidden] { display: none !important; }
.note { font-size: 13px; margin: 12px 0 0; }