问Chrome中的显示表和表格单元格错误

EN

<div class="circle">
  <div class="content">
      <span><h3>heading</h3><p>slogan goes here</p></span>
  </div>
</div>

.circle {
  position: relative;
  width: 0;
  height: 0;
  padding: 20%;
  margin: 1em auto;
  border-radius: 50%;
  background: #a7cd80;
}

.content {
  position: absolute;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  display: table;
  overflow: hidden;  
}
.content span{
  display: table-cell;
  vertical-align: middle;
  text-align: center;
 }
h3{
    line-height: 1px;
}