.card1{
    position: relative;
    width: 400px;
    top:300px;
}
body{
     background: url("bg.jpg");
     animation-name:myfirst;
     animation-duration:12s;
     animation-delay:2s;
     animation-iteration-count:infinite;
 }
@keyframes myfirst
{
    0%   {background:url("bg.jpg");}
    50%  {background:url("bg6.jpg");}
    67%  {background:url("bg5.jpg");}
    100% {background:url("bg.jpg");}
}