body {
    position: relative;
    background-color: #0090f8;
}
html, body {
    margin: 0;
    padding: 0;
    width: 100%;
    min-height: 100vh; 
}
main {
    overflow: auto;
}
.clouds {
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background: url(../assets/main/Sky_Clouds.png) repeat center top;
    animation: movethyclouds 20s linear infinite;
    z-index: -2;
    opacity: 0.5;
}
.bottomclouds {
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background: url(../assets/main/Sky_BottomClouds.png) repeat-x center bottom;
    z-index: -1;
}
@keyframes movethyclouds {
    from {
        background-position: 0 center;
    }
    to {
        background-position: 600px center;
    }
}