@keyframes animate {
    0%{
        transform: translateY(0) rotate(0deg);
        opacity: 1;
        border-radius: 0;
    }
    100%{
        transform: translateY(-1000px) rotate(720deg);
        opacity: 0;
        border-radius: 50%;
    }
}

.background {
    position: fixed;
    width: 100vw;
    height: 100vh;
    top: 0;
    left: 0;
    margin: 0;
    padding: 0;
    background: #668833;
    overflow: hidden;
}
.background li {
    position: absolute;
    display: block;
    list-style: none;
    width: 20px;
    height: 20px;
    background: rgba(255, 255, 255, 0.2);
    animation: animate 19s linear infinite;
}




.background li:nth-child(0) {
    left: 62%;
    width: 121px;
    height: 121px;
    bottom: -121px;
    animation-delay: 1s;
}
.background li:nth-child(1) {
    left: 24%;
    width: 127px;
    height: 127px;
    bottom: -127px;
    animation-delay: 4s;
}
.background li:nth-child(2) {
    left: 30%;
    width: 137px;
    height: 137px;
    bottom: -137px;
    animation-delay: 3s;
}
.background li:nth-child(3) {
    left: 69%;
    width: 184px;
    height: 184px;
    bottom: -184px;
    animation-delay: 1s;
}
.background li:nth-child(4) {
    left: 52%;
    width: 114px;
    height: 114px;
    bottom: -114px;
    animation-delay: 5s;
}
.background li:nth-child(5) {
    left: 55%;
    width: 193px;
    height: 193px;
    bottom: -193px;
    animation-delay: 11s;
}
.background li:nth-child(6) {
    left: 79%;
    width: 101px;
    height: 101px;
    bottom: -101px;
    animation-delay: 1s;
}
.background li:nth-child(7) {
    left: 74%;
    width: 124px;
    height: 124px;
    bottom: -124px;
    animation-delay: 5s;
}
.background li:nth-child(8) {
    left: 89%;
    width: 143px;
    height: 143px;
    bottom: -143px;
    animation-delay: 30s;
}
.background li:nth-child(9) {
    left: 80%;
    width: 172px;
    height: 172px;
    bottom: -172px;
    animation-delay: 31s;
}