Standardized Featured Image

Hi All, I've used catch base in the past, and now I'm reconsidering it as my current theme is frustrating in some aspects. One problem that I have is that I want a standardized featured image size to show regardless of the size of the image itself. For example, I like the size of the featured image in this article: https://smallfirmlegalmarketing.com/seo-for-lawyers-the-essential-guide But this was easy because I created my own image. There are times where I'm just taking an image off the web, which can be any size. For example, this featured image is far too big: https://smallfirmlegalmarketing.com/ruby-receptionists-review-biggest-name-call-centers Is there a custom css code to make every featured image the same standard size?