console
var box = document.querySelector('.box')
var bg = document.querySelector('.bg')
box.onclick = function(){
alert(1)
}
bg.onclick = function(){
alert(2)
}
<div class="flex">
<div class="box flex-item"></div>
</div>
<div class="bg flex"></div>
.box{
width: 100px;
height: 100px;
background-color: #3b98e0;
transform: rotatey(180deg);
-webkit-transform-style: preserve-3d;
transform-style: preserve-3d;
}
.bg{
position: fixed;
top: 0;
bottom: 0;
left: 0;
right: 0;
background-color:#dfdfdf;
opacity: 0.5;
}
.flex{
display: -webkit-box;
display: -webkit-flex;
display: flex;
}
.flex-item{
-webkit-box-flex: 1;
-webkit-flex: 1;
flex: 1;
width: 0%;
}