body {
  font-family: system-ui, sans-serif;
  max-width: 720px;
  margin: 0 auto;
  padding: 1rem;
  color: #1a1a1a;
  background: #fafafa;
}

h1 {
  font-size: 1.5rem;
}

section {
  margin-bottom: 2rem;
}

canvas {
  max-width: 100%;
  border: 1px solid #ddd;
  border-radius: 8px;
}

ul {
  list-style: none;
  padding: 0;
}

li {
  padding: 0.4rem 0;
  border-bottom: 1px solid #eee;
  font-size: 0.9rem;
}

button {
  font-size: 1rem;
  padding: 0.6rem 1.2rem;
  border-radius: 8px;
  border: none;
  background: #2a9d8f;
  color: white;
  cursor: pointer;
}

@media (prefers-color-scheme: dark) {
  body { background: #14171a; color: #e6e6e6; }
  li { border-bottom-color: #2a2f34; }
  canvas { border-color: #2a2f34; }
}