Template:Navgrid/styles.css

.navgrid .simple-group-container tbody {
display: grid;
grid-template-columns: repeat(2, 1fr);
grid-auto-rows: auto;
grid-column-gap: 4px;
grid-row-gap: 4px;
}
.navgrid tr.simple-group-row {
 display: flex;
}
.navgrid td.simple-group {
 width: auto !important;
}
.navgrid td.simple-group::after {
 content: "" !important;
}

.navgrid td.simple-list { border-bottom: none !important; }

@media (max-width: 767.98px) {
    .navgrid .simple-group-container tbody {
        display: flex !important;
        flex-flow: column wrap;
    }
}