*{margin:0;padding:0;}
div{
  width:200px;
   overflow-x:auto;
   border:1px solid #ddd;
  
}
ul{
    width:400px;
	 display:flex;
}
li{
	flex:1;
  list-style:none;
  background:#ddd;
  border:1px solid #ccc;
}