flex 左邊固定寬度，右邊自適應

<div id="flex"> <div id="left">我在邊，定寬</div> <div id="right">我在右邊，自適應</div> </div> 

#flex{ display: flex; } #left{

 width: 200px;

}
 #right{

 background:green;

 flex:1

  }