CSS でスクロールバーの高さをカスタマイズするにはどうすればよいですか?

<code class="css">.wrapper {
  overflow-y: scroll;
  width: 100%;
  height: 100%;

  /* Create a fake scroll track */
  &::after {
    content: '';
    position: absolute;
    width: 5px;
    height: calc(100% - 20px);
    z-index: -1;
    top: 10px;
    background: #666;
    right: -1px;
  }

  /* Customize the scrollbar properties */
  &::-webkit-scrollbar {
    width: 5px;
  }

  &::-webkit-scrollbar-track {
    background: transparent;
  }

  &::-webkit-scrollbar-corner {
    background: transparent;
  }

  &::-webkit-scrollbar-thumb {
    background-color: red;
    border: none;
    border-radius: 5px;
  }

  /* Define the end and start points of the scrollbar thumb */
  &::-webkit-scrollbar-track-piece:end {
    margin-bottom: 10px;
  }

  &::-webkit-scrollbar-track-piece:start {
    margin-top: 10px;
  }
}</code>