.form-block {
    background: var(--light-grey--section-background);
    display: flex;
    gap: 50px;
    padding: 50px;
}

.form-block .item {
    width: calc(1/2*100% - (1 - 1/2)*50px);
}

@media only screen and (max-width:991px) {
    .form-block {
        flex-wrap: wrap;
        padding: 0 0 50px;
    }

    .form-block .item {
        width: 100%;
    }
}