It’s simple. Set your image crop dimensions and use this line in your CSS:
img { object-fit: cover; }That’s it. No need for unsemantic, wrapping divs or any other nonsense.
This technique works great for cropping awkwardly-sized avatar pictures down to squares or circles. Take this wide photo of a bear below for example. Once object-fit: cover is applied to the image and a width and height are set, the photo crops and centers itself.