:root {
  color-scheme: light dark;
  --bg: #ffffff;
  --fg: #16181d;
  --muted: #6b7280;
  --line: #e4e6eb;
  --accent: #2f6feb;
}

@media (prefers-color-scheme: dark) {
  :root {
    --bg: #14161a;
    --fg: #e8eaed;
    --muted: #9aa1ab;
    --line: #2a2e35;
    --accent: #6d9bf5;
  }
}

* { box-sizing: border-box; }

body {
  margin: 0;
  padding: 3rem 1.5rem;
  background: var(--bg);
  color: var(--fg);
  font: 16px/1.6 ui-sans-serif, system-ui, -apple-system, "Segoe UI", sans-serif;
}

#app { max-width: 40rem; margin: 0 auto; }

h1 { margin: 0; font-size: 1.75rem; letter-spacing: -0.01em; }

.sub { margin: 0.25rem 0 2rem; color: var(--muted); }

.card {
  border: 1px solid var(--line);
  border-radius: 10px;
  padding: 1.25rem;
}

button {
  font: inherit;
  padding: 0.5rem 1rem;
  border: 0;
  border-radius: 6px;
  background: var(--accent);
  color: #fff;
  cursor: pointer;
}

button:disabled { opacity: 0.6; cursor: default; }

pre {
  margin: 1rem 0 0;
  padding: 0.75rem;
  overflow-x: auto;
  border-radius: 6px;
  background: color-mix(in srgb, var(--fg) 6%, transparent);
}

.error { color: #d24b4b; }