.box{
width:300px;
height:300px;
background:-webkit-linear-gradient(-30deg,rgba(255,255,255,0) 0,rgba(255,255,255,0)150px,rgba(255,255,255,1) 170px,rgba(255,255,255,1) 180px,rgba(255,255,255,0) 200px)no-repeat -200px 0,url(images/new_bg.png) no-repeat;
transition:1s;
}
.box:hover{
background-position:300px 0,-100px -100px;
}