main {
    grid-template-areas: "box1" "box4" "box2" "box3";
    grid-template-columns: auto;
    padding-bottom: 2em;
    grid-gap: 0;
}

figure,
.form figure {
    width: 90%;
    margin: auto;
}

.form main {
    grid-template-columns: auto;
}

.form main h1:first-child {
    grid-column: 1;
}

.form main section:nth-child(2){
    grid-column: 1;
    grid-row: 3;
}

.form main section:nth-child(3){
    grid-column: 1;
    grid-row: 2;
}

.form main section:nth-child(4){
    grid-column: 1;
    grid-row: 4;
}