body {
  margin: 0;
  padding: 16px;
  font-family: system-ui, sans-serif;
  line-height: 1.7;
  color: #222;
}

h2 {
  font-size: 1rem;
  margin: 24px 0 8px;
}

h2:first-of-type {
  margin-top: 0;
}

.controls {
  margin-bottom: 16px;
  padding: 12px;
  background: #f4f4f4;
  border-radius: 6px;
  font-size: .875rem;
}

.controls label {
  margin-inline-end: 12px;
}

.note {
  font-size: .8125rem;
  color: #555;
}

@supports not (row-rule: 1px solid) {
  .needs-gap-decorations::before {
    content: "このデモはCSS Gap Decorationsを使っています。Chrome / Edge 149以降でご覧ください。";
    display: block;
    padding: 10px;
    margin-bottom: 16px;
    background: #000;
    color: #fff;
    text-align: center;
  }
}