效果图：

<div class="separator">
    文本
</div>

.separator {
  width: 40%;
  border-style: dashed;
  display: flex;
  align-items: center;
  color: #e2e2e2;
  font-size: 14px;
  line-height: 20px;
  border-color: #e2e2e2;
  border-width: 0;
}

.separator::before {
  content: '';
  flex: 1;
  box-sizing: border-box;
  height: 1px;
  border-color: inherit;
  border-style: inherit;
  border-width: 2px 0 0;
  margin-right: 5px;
  padding: 0;
  outline: none;
}

.separator::after {
  content: '';
  flex: 1;
  box-sizing: border-box;
  height: 1px;
  border-color: inherit;
  border-style: inherit;
  border-width: 2px 0 0;
  margin-left: 5px;
  padding: 0;
  outline: none;
}