body {
    background-color: white;
    animation: dayToNight 10s infinite 1.5s;
}

.content {
    position: absolute;
    top: 50%;
    left: 50%;
    transform: translate(-50%, -50%);
    display: block;
}

.sun {
    height: 150px;
    width: 150px;
    border-radius: 50%;
    background-color: #FCD25B;
    border: 3px solid #FCD25B;
    overflow: hidden;
    animation: dayToNight2 10s infinite 1.5s;
}

.shadow {
    height: 170px;
    width: 170px;
    border-radius: 50%;
    background-color: white;
    top: -5px;
    left: 0px;
    animation: moveShadow 10s infinite 1.5s;
}

@keyframes moveShadow {
    0% {
        transform: translateX(150px);
        background-color: white;
    }
    50% {
        transform: translateX(-10px);
        background-color: black;
    }
    100% {
        transform: translateX(-170px);
        background-color: white;
    }
}

@keyframes dayToNight {
    0% {
        background-color: white;
    }
    50% {
        background-color: black;
    }
    100% {
        background-color: white;
    }
}

/*footer*/
.footer{
    margin-bottom: 100%, auto;
}