My site has used the same CSS file for well over a decade without any problems, but about 24 hours ago my site’s layout became garbled even though I only added a single class for a new image I’m trying to use for a capital letter, which I’m only testing on one page so far but the entire site (every page) became garbled and remained so even after I restored the original CSS file without any new modifications at all. I found I could partially solve the problem only by removing the comments within the code (i.e. comments using “//” to add notes to myself explaining what different parts of the code do) even though these comments had never caused any problems prior to yesterday. Worse, the only way to fix centering issues for the layout was to get rid of the mobile-friendly layout I added a few years ago and revert back to my site’s original desktop-only format, which probably isn’t going to work well on mobile and may even lead to Google penalties for not being mobile-friendly. This makes no sense, given that the mobile-friendly format had worked fine for several years up until yesterday. Why would comments suddenly mess everything up, and why would the centering code suddenly fail?