prefer-targeted-element-iframe.html

<!DOCTYPE html>
<html>
  <body>
    <style>
      .scroller {
        overflow: scroll;
        width: 350px;
        height: 350px;
        border: solid 1px black;
        scroll-snap-type: y mandatory;
        position: relative;
        resize: both;
      }
      .large-space {
        height: 300vh;
        width: 300vw;
        position: absolute;
      }
      .snap {
        scroll-snap-align: start;
      }
      .box {
        width: 100px;
        height: 100px;
        background-color: green;
        display: inline-block;
        position: relative;
      }
      .grid {
        position: absolute;
        width: 350px;
        height: 350px;
      }
      .snap:target {
        background-color: blue;
      }
    </style>
    <div class="scroller" id="scroller">
      <div class="large-space"></div>
      <div class="grid" id="grid">
        <div id="box1" class="snap box">Box 1</div>
        <div id="box2" class="snap box">Box 2</div>
        <div id="box3" class="snap box">Box 3</div>
        <div id="box4" class="snap box">Box 4</div>
        <div id="box5" class="snap box">Box 5</div>
        <div id="box6" class="snap box">Box 6</div>
        <div id="box7" class="snap box">Box 7</div>
        <div id="box8" class="snap box">Box 8</div>
        <div id="box9" class="snap box">Box 9</div>
      </div>
    </div>
  </body>
</html>

chromium/third_party/blink/web_tests/external/wpt/css/css-scroll-snap/snap-after-relayout/multiple-aligned-targets/prefer-targeted-element-iframe.html