chromium/third_party/blink/web_tests/external/wpt/css/css-scroll-snap/support/scroll-target-margin-001-iframe.html

<!DOCTYPE html>
<title>iframe for #target and scroll-margin with snapping off (y</title>
<style type='text/css'>
  html, body {
    margin: 0; padding: 0;
  }
  html {
    /* to make failing more obvious */
    background: 0 1em / 100% 1em linear-gradient(red, red) repeat-x fixed;
    /* avoid anti-aliasing issues */
    font: 20px/1 sans-serif;
    scrollbar-width: none;
  }
  div {
    height: 1em;
  }
  #target { scroll-margin: 2em 0 1em; } /* snap area is exact fit for snapport */
  #stripe { background: green;        } /* color part of the snap area         */
  .fail   { color: red;               } /* make failing more obvious           */

  /* emulate `scrollbar-width: none` for browsers that don't support it yet */
  ::-webkit-scrollbar { display: none; }
</style>

<div></div>
<div></div>
<div></div>
<div></div>
<div class="fail">FAIL</div>
<div></div>
<div id="stripe"></div>
<div id="target"></div>
<div></div>
<div class="fail">FAIL</div>
<div></div>
<div></div>
<div></div>
<div></div>