.navBox { display: grid; grid-template-columns: 8em 8em 8em 8em; grid-template-rows: auto; gap: .8em; justify-content: center; margin: 1em 0; }

.navItem a {text-align: center;}

.navItem a:hover {filter: grayscale(50%);}

.navC a {background-color: #366;}

.navH a {background-color: #406194;}

.navM a {
    background-color: #DA612C;
}
.navB a {
    background-color: #A60035;
}
.navBox a {
    display: block;
    padding: 0.5em 0;
    text-decoration: none;
    color: #fff;
}
@media only screen and (max-width: 540px) {
    .navBox {
        grid-template-columns: 8em 8em!important;
    }
}