attr()

attr() 使用 html 属性值

.tech-item:hover::after {
  content: attr(data-title);
  position: absolute;
  top: -10px;
  left: 20px;
  z-index: 1000;
  text-align: center;
  width: max-content;
  background: #f00;
  color: #fff;
  padding: 0 6px;
  height: 25px;
  line-height: 25px;
  font-size: 12px;
}