/* html,
body {
    margin: 0;
    overflow: hidden;
    width: 100%;
    height: 100%;
    background: transparent;
    background: linear-gradient(to bottom, #000000 0%, #5788fe 100%);
} */

.cbox {
    position: absolute;
    top: 0;
    left: 0;
    z-index: 999;
}

.filter {
    width: 100%;
    height: 100%;
    position: absolute;
    top: 0;
    left: 0;
    background: transparent;
    animation: colorChange 30s ease-in-out infinite;
    animation-fill-mode: both;
    mix-blend-mode: overlay;
}

@keyframes colorChange {
    0%,
    100% {
        opacity: 0;
    }
    50% {
        opacity: .9;
    }
}