:root {
  --bg: #ffffff;
  --text: #1f2937;
  --muted: #6b7280;
  --border: #e5e7eb;
  --accent: #2563eb;
}

* {
  box-sizing: border-box;
}

html {
  font-size: 16px;
}

body {
  margin: 0;

  background: var(--bg);
  color: var(--text);

  font-family:
    Inter,
    system-ui,
    -apple-system,
    BlinkMacSystemFont,
    "Segoe UI",
    sans-serif;

  line-height: 1.6;
}

header {
  border-bottom: 1px solid var(--border);
}

nav {
  max-width: 900px;

  margin: 0 auto;
  padding: 1rem 1.5rem;

  display: flex;
  gap: 1rem;
}

main {
  max-width: 900px;

  margin: 0 auto;
  padding: 3rem 1.5rem;
}

footer {
  max-width: 900px;

  margin: 0 auto;
  padding: 2rem 1.5rem;

  color: var(--muted);

  border-top: 1px solid var(--border);
}

h1 {
  margin-top: 0;
  margin-bottom: 1rem;

  font-size: 2.5rem;
  line-height: 1.1;
}

h2 {
  margin-top: 3rem;
  margin-bottom: 1rem;

  padding-bottom: 0.5rem;

  border-bottom: 1px solid var(--border);

  font-size: 1.5rem;
}

p {
  margin-bottom: 1rem;
}

ul {
  padding-left: 1.25rem;
}

li {
  margin-bottom: 0.5rem;
}

a {
  color: var(--accent);
  text-decoration: none;
}

a:hover {
  text-decoration: underline;
}

code {
  padding: 0.15rem 0.35rem;

  border-radius: 4px;

  background: #f3f4f6;

  font-size: 0.95rem;
}

pre {
  padding: 1rem;

  border: 1px solid var(--border);
  border-radius: 8px;

  background: #fafafa;

  overflow-x: auto;
}

.demo-card {
  padding: 1rem;

  border: 1px solid var(--border);
  border-radius: 8px;

  background: #fafafa;
}

.playground {
  display: flex;
  flex-direction: column;
  gap: 1rem;
}

.playground-btn {
  width: fit-content;

  padding: 0.65rem 1rem;

  border: 1px solid var(--border);
  border-radius: 6px;

  background: white;

  cursor: pointer;

  font: inherit;
}

.playground-btn:hover:not(:disabled) {
  background: #f8fafc;
}

.playground-btn:disabled {
  opacity: 0.7;
  cursor: not-allowed;
}

.product-card {
  padding: 1rem;

  border: 1px solid var(--border);
  border-radius: 8px;

  background: white;
}

.product-card h4 {
  margin-top: 0;
  margin-bottom: 0.75rem;
}

.product-card ul {
  margin: 0;
}

.error-message {
  color: #dc2626;
}