art;
      }
    </style>
  </head>

  <body>
    <section class="preview">
      <article class="scroller">
        <h1>Sticky Heading</h1>
        <section>
          <h2>Section one</h2>
        </section>
        <section>
          <h2>Section two</h2>
        </section>
        <section>
          <h2>Section three</h2>
        </section>
      </article>
    </section>

    <textarea class="playable playable-css" style="height: 170px">
.scroller {
  height: 300px;
  overflow-y: scroll;
  scroll-snap-