body {
    margin: 0;
}
header {
    width: 100%;
    height: 20vh;
    background: linear-gradient(to bottom, hsl(215, 100%, 50%), hsl(221, 100%, 55%));
}
main{
    display: flex;
    width: 100%;
    background-color: antiquewhite;
    height: 70vh;
}
section.main {
    width: 70%;
    height: 100%;
}
aside {
    width: 30%;
    height: 100%;
    background-color: aqua;
}

footer {
    width: 100%;
    height: 20vh;
    background: linear-gradient(to bottom, hsl(134, 100%, 50%), hsl(91, 100%, 55%));
}