.main-grid {
    display: grid;
    grid-template-areas:
    "header header"
    "left main"
    "footer footer";
    grid-template-columns: 1fr 1fr;
    grid-gap: 20px;
}

header {
    grid-area: header;
    background-color: #7fffd4;
    background-image: url(https://www.pakutaso.com/shared/img/thumb/miyakojima-12693_TP_V.jpg);
    background-size: cover;
}

aside {
    grid-area: left;
    background-color: #98fb98;
}

article {
    grid-area: main ;
    background-color: #e6e6fa;
}

footer {
    grid-area: footer;
    background-color: #7fffd4;
    background-image: url(https://cdn.dribbble.com/users/470545/screenshots/4339126/fish-animation_v1.gif);
    background-size: contain;
    background-repeat: repeat;
}
type="text/css"