:root {
  color-scheme: light dark;
  --bg: #121820;
  --surface: #2e3846;
  --border: #556274;
  --text: #f4f6f8;
}

@media (prefers-color-scheme: light) {
  :root {
    --bg: #f5f6f8;
    --surface: #ffffff;
    --border: #e5e5e5;
    --text: #121820;
  }
}

* {
  box-sizing: border-box;
}

html,
body {
  margin: 0;
  min-height: 100%;
}

body {
  font-family: system-ui, -apple-system, Segoe UI, sans-serif;
  background: var(--bg);
  color: var(--text);
  display: flex;
  align-items: center;
  justify-content: center;
  padding: 32px 20px;
}

.panel {
  width: 100%;
  max-width: 36rem;
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: 12px;
  padding: 28px;
}

h1 {
  margin: 0;
  font-size: 1.75rem;
  font-weight: 700;
  text-align: center;
}