仅使用CSS将文本转换为带有作为工具提示的内容的图标

<span class="tooltip">文本</span>

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

.tooltip::before {
  content: "";
  position: absolute;
  top: -20px;
  left: 50%;
  transform: translateX(-50%);
  width: 100px;
  height: 20px;
  background-color: #000;
  color: #fff;
  text-align: center;
  line-height: 20px;
  font-size: 12px;
  opacity: 0;
  visibility: hidden;
  transition: opacity 0.3s, visibility 0.3s;
}

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

.tooltip::after {
  content: "";
  position: absolute;
  top: -10px;
  left: 50%;
  transform: translateX(-50%);
  border-width: 5px;
  border-style: solid;
  border-color: transparent transparent #000 transparent;
  opacity: 0;
  visibility: hidden;
  transition: opacity 0.3s, visibility 0.3s;
}

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