Vue 用label在div中画一条垂直居中的线条

<div id='three_dot_view'>
   <label class="gray_line"></label>
</div>

#three_dot_view, {
  width: 330px;
  height: 20px;
}

.gray_line {
  background: #e5e5e5;
  width: 80px;
  height: 2px;
  float: left;
  margin: 10px 5px;
}