CSS force image resize and keep aspect ratio

Question

I am working with images, and I ran across a problem with aspect ratios.

Answer 1

I would suggest for a responsive approach the best practice would be using the Viewport units and min/max attributes as follows:

img{
  display: block;
  width: 12vw;
  height:12vw;
  max-width:100%;
  min-width:100px;
  min-height:100px;
  object-fit:contain;
}