I am working with images, and I ran across a problem with aspect ratios.
Very similar to some answers here, but in my case I had images that sometimes were taller, sometimes larger.
This style worked like a charm to make sure that all images use all available space, keep the ratio and not cuts:
.img {
object-fit: contain;
max-width: 100%;
max-height: 100%;
width: auto;
height: auto;
}