html, body {
    height: 100%;
}

body {
    margin: 0;

    background: linear-gradient(-45deg,#FFD89B, #FFE2B4, #FFECCE, #FFF6E8, #FFFFFF);
    background-size: 400% 400%;
    animation: gradient 10s ease infinite;
}

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