Corrections in html file for responsiveness

I have an html file that was created via Word (unnecessarily lengthy, but it works) of a document with images that I want to upload to Facebook and have it render correctly both on mobile devices and desktop (responsive). I made a few quick modifications to the html to add viewport code and the text now appears to render just fine. However, I cannot get the jpeg images to render correctly. I tried adjusting using “object-fit: contain” and percentages instead of pixels, but my coding skills are fairly basic and I have not been successful in getting this to work. I would like this corrected and the changes that are made to be highlighted in yellow in a Notepad file, so that I will have a guide to be able to make similar modifications in the future. This is a very quick and minor coding project and I cannot see that an experienced programmer should require more than an hour to do it. I’m willing to pay for up to two hours to get this done, however, and if it is successful, I will have other more extensive work to be done in the future. Thanks.