grid-template-areas: ""; Is it possible to span a particular div across multiple rows & columns?
For example:
.container-3{
    display: grid;
    grid-template-area: 
    "m m m m h h h h h h h h "
    "m c c c c c c c c c c c"
    "m f f f f f f f f f f f";
    gap:10px;
    padding-bottom: 500px;
}
.header1{
    grid-area: h ;
}
.menu1{
    grid-area: m;
    background-color: orange;
}
.content1{
    grid-area: c;
}
.footer1{
    grid-area: f;
}