body {
    background-color: Azure;
}
html, body {
    width: 100%;
    height:100%;
}

body {
    background: linear-gradient(-45deg, #F7BBA9, #F39EBF, #91D3EA, #91EAD5);
    background-size: 400% 1600%;
    animation: gradient 45s ease infinite;
}

@keyframes gradient {
    0% {
        background-position: 0% 50%;
    }
    50% {
        background-position: 100% 50%;
    }
    100% {
        background-position: 0% 50%;
    }
}