body:before {
content: " ";
height: 100vh;
width: 100vw;
display: block;
position: fixed;
top: 0;
left: 0;
z-index: 100;
background-image: url('kiraa.gif');
background-size: cover;
background-repeat: no-repeat;
background-position:center;
animation: yourAnimation 1s ease 1s 1 normal forwards;
pointer-events: none;}
@keyframes yourAnimation { 0.0%{ opacity: 1;} 75%{ opacity: 1; } 100%{ opacity: 0;}
}