W3.css and Dreamweaver?

[jodel_from_aol]

I am the owner of the Red Hen Publications website, which is in serious need of a rebuild/redesign due to proliferating glitches in my dropdown menus which is now affecting the buttons in the nav bar which do not even have dropdowns. (No. I do not know what is causing this. I have not changed the .css style sheets since I uploaded the site, and this was not present at that time. But over the past 2 years the site has become more and more affected.)

The site was built in Dreamweaver CC2021, and since you people wrote the Classroom in a Book, I figured that this would be an appropriate place to get some suggestions. I will say that so long as the program runs on my iMac I will probably continue to use it, but my own preferences are for something other than the dummy site which was built by following the instructions of the book. I avoided Bootstrap when building my own site, but then, the current site was intended as a stop-gap. The previous build, done in CS6 back in 2013 depended upon Spry assets which are no longer supported.

I am seeing a heading for W3.css methods of producing various effects in a site. Are these supported in Dreamweaver CC2021? I would just as soon not start counting on using something that the program cannot handle.