.image-mosaic 
{   
    margin-left: 20%;
    margin-right: 20%;
    display: grid;
    gap: 1rem;
    grid-template-columns: repeat(auto-fit, minmax(240px, 1fr));
    grid-auto-rows: 145px;
}
  
.card
{
    filter:grayscale(0.8);
    cursor: pointer;
    display: flex;
    flex-direction: column;
    justify-content: center;
    align-items: center;
    background-size:contain;
    background-position :center;
    background-repeat: no-repeat;
    height: 100%;
    width: 100%;
    transition: all 500ms;
    overflow: auto;
}

.card:hover
{
  filter:grayscale(0);
  height: 105%;
  width: 105%;
  transform: translate3d(-2.5%,-2.5%,0);
}

@media screen and (min-width: 600px) 
{
    .card-tall 
    {
      grid-row: span 2 / auto;
    }
  
    .card-wide 
    {
      grid-column: span 2 / auto;
    }
}