CSS: 100% width or height while keeping aspect ratio?

Question

Currently, with STYLE, I can use width: 100% and auto on the height (or vice versa), but I still can\'t constrain the image into a specific positio

Answer 1

Simple elegant working solution:

img {
  width: 600px;  /*width of parent container*/
  height: 350px; /*height of parent container*/
  object-fit: contain;
  position: relative;
  top: 50%;
  transform: translateY(-50%);
}