css实现内凹圆

实现效果

html

<div id="post-form">
	 <div class="formbox"></div>
	 <div class="rightform"></div>
</div>

css 样式

#post-form{
    padding:50px 10px;
    background:#fff;
    margin:30px auto;
    width:90%;
    border-radius:10px;
    position:relative;
}
 .formbox{
      position: absolute;
      top: 50%;
      left:-2px;
      transform: translate(-50%,-50%);
      width: 20px;
      height:20px;
      background:#2EB267;
      z-index:9;
      border-radius:50%;
 }
   .rightform{
        position: absolute;
        top: 50%;
        right:-23px;
        transform: translate(-50%,-50%);
        width: 20px;
        height:20px;
        background:#2EB267;
        z-index:9;
        border-radius:50%;
   }