HTML、CSS、jQuery を使用してカスタム スクロールバーを作成する方法

<div class="scroll-area">
  <div class="content">
    <!-- 这里是需要滚动的内容 -->
  </div>
</div>
<div class="scrollbar">
  <div class="thumb"></div>
</div>

.scroll-area {
  width: 300px;
  height: 200px;
  overflow: hidden;
  position: relative;
}
.content {
  width: 100%;
  height: 1000px; /* 这里是需要滚动的内容的高度 */
}
.scrollbar {
  position: absolute;
  top: 0;
  right: 0;
  width: 10px;
  height: 100%;
  background-color: #eee;
}
.thumb {
  width: 100%;
  height: 50px; /* 这里是滚动条的高度 */
  background-color: #999;
  cursor: pointer;
}

$(document).ready(function() {
  var $area = $('.scroll-area'),
      $content = $('.content'),
      $scrollbar = $('.scrollbar'),
      $thumb = $('.thumb');
  
  var contentHeight = $content.height(),
      areaHeight = $area.height(),
      scrollbarHeight = (areaHeight / contentHeight) * areaHeight,
      thumbHeight = scrollbarHeight;
  
  $thumb.height(thumbHeight);
  
  $thumb.draggable({
    axis: 'y',
    containment: 'parent',
    drag: function(event, ui) {
      var dragOffset = ui.position.top,
          scrollbarOffset = (dragOffset / areaHeight) * contentHeight;
      
      $content.css('top', -scrollbarOffset);
    }
  });
});