代码部分

<style>
.box{
  width: 100%;
  height: 100px;
  display: flex;
  align-items: center;
  justify-content: center;
  background: linear-gradient(to right, #fff 50%, #000 50%);
}
span{
  font-size: 30px;

  /* 根据背景色计算前景色差值 */
  mix-blend-mode: difference;
  color: #fff;
}
</style>
<div class="box">
  <span>周明博客：zekibu.im</span>
</div>

实现效果

周明博客：zekibu.im