.centered-grid-item {
    width: 100%;
}

@media (min-width: 640px) {
    .centered-grid-item {
        width: calc((100% - 0.5rem * 1) / 2);
    }
}

@media (min-width: 768px) {
    .centered-grid-item {
        width: calc((100% - 0.5rem * 2) / 3);
    }
}

@media (min-width: 1024px) {
    .centered-grid-item {
        width: calc((100% - 0.5rem * 3) / 4);
    }
}

@media (min-width: 1280px) {
    .centered-grid-item {
        width: calc((100% - 0.5rem * 5) / 6);
    }
}