将按钮粘贴到可滚动div的右上角

<div class="scrollable-div">
  <!-- 其他内容 -->
  <button class="scrollable-button">按钮</button>
</div>

.scrollable-div {
  position: relative;
  overflow: auto;
  /* 其他样式 */
}

.scrollable-button {
  position: absolute;
  top: 0;
  right: 0;
  z-index: 999;
  /* 其他样式 */
}

const scrollableDiv = document.querySelector('.scrollable-div');
const scrollableButton = document.querySelector('.scrollable-button');

scrollableDiv.addEventListener('scroll', function() {
  const scrollTop = scrollableDiv.scrollTop;
  const scrollLeft = scrollableDiv.scrollLeft;
  
  scrollableButton.style.top = scrollTop + 'px';
  scrollableButton.style.right = -scrollLeft + 'px';
});