:root {
  color-scheme: light;
  --bg: #f5f8f6;
  --surface: #ffffff;
  --text: #15201a;
  --muted: #5a6761;
  --line: #d3ddd8;
  --accent: #00873c;
  --on-accent: #ffffff;
  --code-bg: #e5f6ec;
  --shadow: 0 1px 2px rgba(16, 40, 26, 0.04), 0 10px 30px rgba(16, 40, 26, 0.08);
}

@media (prefers-color-scheme: dark) {
  :root {
    color-scheme: dark;
    --bg: #0e1311;
    --surface: #151b18;
    --text: #e4ebe7;
    --muted: #9ba8a1;
    --line: #34413a;
    --accent: #5fd68e;
    --on-accent: #0b1a11;
    --code-bg: rgba(95, 214, 142, 0.14);
    --shadow: none;
  }
}

* { box-sizing: border-box; }

[hidden] { display: none !important; }

html { -webkit-text-size-adjust: 100%; }

body {
  margin: 0;
  min-height: 100vh;
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  gap: 24px;
  padding: 24px 16px;
  background: var(--bg);
  color: var(--text);
  font: 16px/1.6 "Be Vietnam Pro", system-ui, -apple-system, "Segoe UI", Roboto, sans-serif;
  -webkit-font-smoothing: antialiased;
}

.card {
  width: 100%;
  max-width: 440px;
  padding: 32px 24px;
  background: var(--surface);
  border: 1px solid var(--line);
  border-radius: 24px;
  box-shadow: var(--shadow);
  text-align: center;
}

.app-icon {
  display: block;
  margin: 0 auto 16px;
  border-radius: 18px;
}

h1 {
  margin: 0 0 8px;
  font-size: 1.5rem;
  line-height: 1.3;
  font-weight: 700;
}

p { margin: 0 0 16px; }

.code-label {
  margin: 24px 0 4px;
  color: var(--muted);
  font-size: 0.875rem;
}

.code {
  display: inline-block;
  margin: 0 0 24px;
  padding: 8px 20px;
  border-radius: 12px;
  background: var(--code-bg);
  font-size: 2rem;
  font-weight: 700;
  letter-spacing: 0.12em;
  font-variant-numeric: tabular-nums;
}

.button {
  display: flex;
  align-items: center;
  justify-content: center;
  min-height: 48px;
  margin: 0 0 12px;
  padding: 10px 20px;
  border: 1px solid var(--accent);
  border-radius: 999px;
  color: var(--accent);
  font-weight: 600;
  text-decoration: none;
}

.button.primary {
  background: var(--accent);
  color: var(--on-accent);
}

.button:focus-visible,
.footer a:focus-visible {
  outline: 3px solid var(--accent);
  outline-offset: 3px;
}

.hint,
.note {
  margin: 8px 0 0;
  color: var(--muted);
  font-size: 0.875rem;
}

.footer {
  display: flex;
  flex-wrap: wrap;
  justify-content: center;
  gap: 8px 24px;
  font-size: 0.875rem;
}

.footer a {
  display: inline-flex;
  align-items: center;
  min-height: 48px;
  color: var(--accent);
  text-underline-offset: 3px;
}