Caja de herramientas

.dos, .tres, .cuatro {
    display: grid;
    gap: 2rem;
}
@media (min-width: 768px)
.dos {
    grid-template-columns: 1fr 1fr;
.tres {
    grid-template-columns: 1fr 1fr 1fr;
.cuatro {
    grid-template-columns: 1fr 1fr 1fr 1fr;    
}

img {
	width: 100%;
    max-width: 100%;
    height: auto;
}