ontainer-type: inline-size;
  }
  #target {
    background-color: black;
  }

  /* Matches with or without a scrollbar: */
  @container (max-width: 100px) {
    #target {
      background-color: blue;
    }
  }

  /* Matches only when there's a scrollbar: */
  @container (max-width: 99px) {
    #target {
      background-color: green;
      font-size: 10px;
      transition: 2s steps(2, start) background-color;
    }
  }
</style>
<div id=scrollable>
  <div id=container>
    <div id=target>
      Foo bar foo