用CSS3做出逐渐发光的方格边框实现步骤

<div>
         <img src="http://tva2.sinaimg.cn/crop.0.0.180.180.180/6830a53bjw8f2qo4xzc2zj20500500t0.jpg"/>
         <div>
                   <p>CSS3 逐渐发光的方格边框</p>
                   <p>CSS3 逐渐发光的方格边框</p>
         </div>
</div>
Css代码
.light{
         background: #fff;
         width: 180px;
         height: 180px;
         margin: 100px auto;
         position: relative;
         text-align: center;
         color: #333;
         transform:translate3d(0,0,0);
 
}
.light-inner{
         padding: 60px 30px 0;
         pointer-events: none;
         position: absolute;
         left: 0;
         top: 0;
         bottom: 0;
         right: 0;
         text-align: center;
         transition: background 0.35s;
         backface-visibility: hidden;
}
.light-inner:before, .light-inner:after{
         display: block;
         content: "";
         position: absolute;
         left: 30px;
         top: 30px;
         right: 30px;
         bottom: 30px;
         border: 1px solid #fff;
         opacity: 0;
         transition: opacity 0.35s, transform 0.35s;
}
.light-inner:before{
         border-left: 0;
         border-right: 0;
         transform:scaleX(0,1);
}
.light-inner:after{
         border-top: 0;
         border-bottom: 0;
         transform: scaleY(1,0);
}
.light:hover .light-inner{
         background: #458fd2
}
.light:hover .light-inner:before, .light:hover .light-inner:after{
         opacity: 1;
         transform: scale3d(1,1,1);
}
 
.light-inner p{
         transition: opacity .35s, transform 0.35s;
         transform: translate3d(0,20px,0);
         color: #fff;
         opacity: 0;
         line-height: 30px;
}
.light:hover .light-inner p{
         transform: translate3d(0,0,0);
         opacity: 1;
}