<!DOCTYPE html>
<html>
<meta charset="utf-8">
<title>CSS Test Reference</title>
<style>
  .line {
    display: flex;
  }

  .container {
    writing-mode: horizontal-tb;
    direction: ltr;
    block-size: 200px;
    inline-size: 200px;
    overflow-y: hidden;
    margin: 10px;
    background: deepskyblue;
  }

  .content {
    inline-size: 100%;
    block-size: 200%;
    background: lightsalmon;
  }

  .width-auto {
    scrollbar-width: auto;
  }

  .width-thin {
    scrollbar-width: thin;
  }

  .width-none {
    scrollbar-width: none;
  }

  .gutter-stable {
    scrollbar-gutter: stable;
  }

  .gutter-both {
    scrollbar-gutter: stable both-edges;
  }
  </style>

  <div class="line">
    <div id="stable-auto" class="container gutter-stable width-none">
      <div class="content"></div>
    </div>
    <div id="both-auto" class="container gutter-both width-none">
      <div class="content"></div>
    </div>
  </div>

  <div class="line">
    <div id="stable-thin" class="container gutter-stable width-auto">
      <div class="content"></div>
    </div>
    <div id="both-thin" class="container gutter-both width-auto">
      <div class="content"></div>
    </div>
  </div>

  <div class="line">
    <div id="stable-none" class="container gutter-stable width-thin">
      <div class="content"></div>
    </div>
    <div id="both-none" class="container gutter-both width-thin">
      <div class="content"></div>
    </div>
  </div>
</html>
