.cuadrados {
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    z-index: -1;
}

.cuadrados li {
    position: absolute;
    list-style: none;
    display: block;
    width: 40px;
    height: 40px;
    background-color: rgba(255, 255, 255, 0.15);
    bottom: -160px;
    -webkit-animation: square 25s infinite linear;
    -moz-animation: square 25s infinite linear;
    animation: square 25s infinite linear;
    border-radius: 20%;
}

.cuadrados li:nth-child(1) {
    left: 10%;
}

.cuadrados li:nth-child(2) {
    left: 20%;
    width: 80px;
    height: 80px;
    -webkit-animation-delay: 0.8s;
    -moz-animation-delay: 0.8s;
    animation-delay: 0.8s;
    -webkit-animation-duration: 1s;
    -moz-animation-duration: 1s;
    animation-duration: 1s;
}

.cuadrados li:nth-child(3) {
    left: 25%;
    -webkit-animation-delay: 0.8s;
    -moz-animation-delay: 0.8s;
    animation-delay: 0.8s;
    -webkit-animation-duration: 3s;
    -moz-animation-duration: 3s;
    animation-duration: 3s;
}

.cuadrados li:nth-child(4) {
    left: 40%;
    width: 60px;
    height: 60px;
    -webkit-animation-delay: 0.5s;
    -moz-animation-delay: 0.5s;
    animation-delay: 0.5s;
    -webkit-animation-duration: 2s;
    -moz-animation-duration: 2s;
    animation-duration: 2s;
    background-color: rgba(255, 255, 255, 0.25);
}

.cuadrados li:nth-child(5) {
    left: 70%;
}

.cuadrados li:nth-child(6) {
    left: 80%;
    width: 120px;
    height: 120px;
    -webkit-animation-delay: 0.5s;
    -moz-animation-delay: 0.5s;
    animation-delay: 0.5s;
    -webkit-animation-duration: 2s;
    -moz-animation-duration: 2s;
    animation-duration: 2s;
    background-color: rgba(255, 255, 255, 0.2);
}

.cuadrados li:nth-child(7) {
    left: -15%;
    width: 160px;
    height: 160px;
    -webkit-animation-delay: 0.5s;
    -moz-animation-delay: 0.5s;
    animation-delay: 0.5s;
    -webkit-animation-duration: 2s;
    -moz-animation-duration: 2s;
    animation-duration: 2s;
}

.cuadrados li:nth-child(8) {
    left: 55%;
    width: 20px;
    height: 20px;
    -webkit-animation-delay: 0.5s;
    -moz-animation-delay: 0.5s;
    animation-delay: 0.5s;
    -webkit-animation-duration: 2s;
    -moz-animation-duration: 2s;
    animation-duration: 2s;
}

.cuadrados li:nth-child(9) {
    left: 25%;
    width: 10px;
    height: 10px;
    -webkit-animation-delay: 0.5s;
    -moz-animation-delay: 0.5s;
    animation-delay: 0.5s;
    -webkit-animation-duration: 2s;
    -moz-animation-duration: 2s;
    animation-duration: 2s;
    background-color: rgba(255, 255, 255, 0.3);
}

.cuadrados li:nth-child(10) {
    left: 90%;
    width: 160px;
    height: 160px;
    -webkit-animation-delay: 1.2s;
    -moz-animation-delay: 1.2s;
    animation-delay: 1.2s;
    -webkit-animation-duration: 2s;
    -moz-animation-duration: 2s;
    animation-duration: 2s;
}

.cuadrados li:nth-child(11) {
    left: 15%;
    width: 17px;
    height: 17px;
    -webkit-animation-duration: 2s;
    -moz-animation-duration: 2s;
    animation-duration: 2s;
    background-color: rgba(255, 255, 255, 0.5);
}

.cuadrados li:nth-child(12) {
    left: 20%;
    width: 5px;
    height: 5px;
    -webkit-animation-delay: 0.5s;
    -moz-animation-delay: 0.5s;
    animation-delay: 0.5s;
    -webkit-animation-duration: 2s;
    -moz-animation-duration: 2s;
    animation-duration: 2s;
    background-color: rgba(255, 255, 255, 0.1);
}

.cuadrados li:nth-child(13) {
    left: 45%;
    width: 8px;
    height: 8px;
    -webkit-animation-delay: 0.5s;
    -moz-animation-delay: 0.5s;
    animation-delay: 0.5s;
    -webkit-animation-duration: 1s;
    -moz-animation-duration: 1s;
    animation-duration: 1s;
    background-color: rgba(255, 255, 255, 0.3);
}

.cuadrados li:nth-child(14) {
    left: 50%;
    width: 120px;
    height: 120px;
    -webkit-animation-delay: 1s;
    -moz-animation-delay: 1s;
    animation-delay: 1s;
    -webkit-animation-duration: 2s;
    -moz-animation-duration: 2s;
    animation-duration: 2s;
    background-color: rgba(255, 255, 255, 0.35);
}

.cuadrados li:nth-child(15) {
    left: 67%;
    width: 50px;
    height: 50px;
    -webkit-animation-delay: 1s;
    -moz-animation-delay: 1s;
    animation-delay: 1s;
    -webkit-animation-duration: 1s;
    -moz-animation-duration: 1s;
    animation-duration: 1s;
    background-color: rgba(255, 255, 255, 0.5);
}

.cuadrados li:nth-child(16) {
    left: 75%;
    width: 20px;
    height: 20px;
    -webkit-animation-delay: 1s;
    -moz-animation-delay: 1s;
    animation-delay: 1s;
    -webkit-animation-duration: 2s;
    -moz-animation-duration: 2s;
    animation-duration: 2s;
    background-color: rgba(255, 255, 255, 0.3);
}

.cuadrados li:nth-child(17) {
    left: 10%;
    width: 10px;
    height: 10px;
    -webkit-animation-delay: 1s;
    -moz-animation-delay: 1s;
    animation-delay: 1s;
    -webkit-animation-duration: 2s;
    -moz-animation-duration: 2s;
    animation-duration: 2s;
    background-color: rgba(255, 255, 255, 0.45);
}

.cuadrados li:nth-child(18) {
    left: 55%;
    width: 10px;
    height: 10px;
    -webkit-animation-delay: 1s;
    -moz-animation-delay: 1s;
    animation-delay: 1s;
    -webkit-animation-duration: 1s;
    -moz-animation-duration: 1s;
    animation-duration: 1s;
    background-color: rgba(255, 255, 255, 0.4);
}

.cuadrados li:nth-child(19) {
    left: 59%;
    width: 10px;
    height: 10px;
    -webkit-animation-delay: 1s;
    -moz-animation-delay: 1s;
    animation-delay: 1s;
    -webkit-animation-duration: 1s;
    -moz-animation-duration: 1s;
    animation-duration: 1s;
    background-color: rgba(255, 255, 255, 0.4);
}

.cuadrados li:nth-child(20) {
    left: 5%;
    width: 15px;
    height: 15px;
    -webkit-animation-delay: 1s;
    -moz-animation-delay: 1s;
    animation-delay: 1s;
    -webkit-animation-duration: 1s;
    -moz-animation-duration: 1s;
    animation-duration: 1s;
    background-color: rgba(255, 255, 255, 0.25);
}


/* * Animaciones */

@-webkit-keyframes square {
    0% {
        -webkit-transform: translateY(0);
        transform: translateY(0);
    }
    100% {
        -webkit-transform: translateY(-100%) rotate(600deg);
        transform: translateY(-100%) rotate(600deg);
    }
}

@-moz-keyframes square {
    0% {
        -moz-transform: translateY(0);
        transform: translateY(0);
    }
    100% {
        -moz-transform: translateY(-100%) rotate(600deg);
        transform: translateY(-100%) rotate(600deg);
    }
}

@keyframes square {
    0% {
        -webkit-transform: Scale(0) translateY(0);
        transform: Scale(0) translateY(0);
    }
    100% {
        -webkit-transform: Scale(1.9) translateY(-1500px);
        transform: Scale(1.9) translateY(-1500px);
    }
}


/*

objeto
<ul class="cuadrados">
            <li></li>
            <li></li>
            <li></li>
            <li></li>
            <li></li>
            <li></li>
            <li></li>
            <li></li>
            <li></li>
            <li></li>
            <li></li>
            <li></li>
            <li></li>
            <li></li>
            <li></li>
            <li></li>
            <li></li>
        </ul>
        
        
        */