.area{
    background: #121212;  
     /* background: -webkit-linear-gradient(to left, #8f94fb, #4e54c8); */
     width: 100%;
     position:fixed;
     min-height: 400vh !important;
     height: 100%;
    /*THE .AREA HEIGHT NEEDS TO BE THE SAME VALUE AS THE .CIRCLES HEIGHT*/
     z-index:-1;
}
 .circles{
     position: absolute;
     top: 0;
     left: 0;
     width: 100%;
     min-height: 400vh !important;
     height: 100%;
     position:fixed;
    /*THE .AREA HEIGHT NEEDS TO BE THE SAME VALUE AS THE .CIRCLES HEIGHT*/
     overflow: hidden;
}
 .circles li{
     position:fixed;
     display: block;
     list-style: none;
     width: 20px;
     height: 20px;
     background: rgba(255, 255, 255, 0.2);
     animation: animate 25s linear infinite;
     bottom: -150px;
}
 .circles li:nth-child(1){
     left: 25%;
     width: 80px;
     height: 80px;
     animation-delay: 0s;
}
 .circles li:nth-child(2){
     left: 10%;
     width: 20px;
     height: 20px;
     animation-delay: 2s;
     animation-duration: 12s;
}
 .circles li:nth-child(3){
     left: 70%;
     width: 20px;
     height: 20px;
     animation-delay: 4s;
}
 .circles li:nth-child(4){
     left: 40%;
     width: 60px;
     height: 60px;
     animation-delay: 0s;
     animation-duration: 18s;
}
 .circles li:nth-child(5){
     left: 65%;
     width: 20px;
     height: 20px;
     animation-delay: 0s;
}
 .circles li:nth-child(6){
     left: 75%;
     width: 110px;
     height: 110px;
     animation-delay: 3s;
}
 .circles li:nth-child(7){
     left: 35%;
     width: 150px;
     height: 150px;
     animation-delay: 7s;
}
 .circles li:nth-child(8){
     left: 50%;
     width: 25px;
     height: 25px;
     animation-delay: 15s;
     animation-duration: 45s;
}
 .circles li:nth-child(9){
     left: 20%;
     width: 15px;
     height: 15px;
     animation-delay: 2s;
     animation-duration: 35s;
}
 .circles li:nth-child(10){
     left: 85%;
     width: 150px;
     height: 150px;
     animation-delay: 0s;
     animation-duration: 11s;
}
 @keyframes animate {
     0%{
         transform: translateY(0) rotate(0deg);
         opacity: 1;
         border-radius: 0;
    }
     100%{
         transform: translateY(-1000px) rotate(720deg);
         opacity: 0;
         border-radius: 50%;
    }
}