.box{position:relative;background:rgba(15,23,42,.8);border-radius:8px!important;border:1px solid #1f223c;float:left;cursor:pointer}.box:before{content:"";background:linear-gradient(45deg,red,#ff7300,#fffb00,#48ff00,#00ffd5,#002bff,#7a00ff,#ff00c8,red);position:absolute;top:-2px;left:-2px;-webkit-background-size:400%;background-size:400%;z-index:-1;filter:blur(5px);width:calc(100% + 4px);height:calc(100% + 4px);animation:animate 20s linear infinite;opacity:0;transition:opacity .3s ease;border-radius:8px!important}.box:hover:before{opacity:1;border-radius:8px!important}.box:after{z-index:-1;content:"";position:absolute;width:100%;height:100%;background:rgba(15,23,42,.8);left:0;top:0}@keyframes animate{0%{background-position:0 0}50%{background-position:400% 0}to{background-position:0 0}}