body {
  font-family: 'Inter', sans-serif;
  background: #fff;
  color: #111;
  padding: 1.5em;
  max-width: 800px;
  margin: 0 auto;
}
h1 {
  font-size: 2em;
  margin-bottom: 1em;
  border-bottom: 1px solid #ccc;
  padding-bottom: 0.25em;
}
canvas {
  background: #f8f8f8;
  border-radius: 12px;
  padding: 1em;
}