如何更改工具提示背景颜色？

<span class="tooltip">Hover over me</span>

.tooltip {
  position: relative;
  display: inline-block;
  cursor: pointer;
}

.tooltip::after {
  content: "";
  position: absolute;
  top: 100%;
  left: 50%;
  transform: translateX(-50%);
  padding: 5px;
  background-color: #f1f1f1; /* 设置背景颜色 */
  color: #000;
  border-radius: 5px;
  font-size: 12px;
  opacity: 0;
  transition: opacity 0.3s;
  visibility: hidden;
}

.tooltip:hover::after {
  opacity: 1;
  visibility: visible;
}