Wow! Looks great to me. I can see the borders you mention.
I will try it later from my laptop, I use my cellphone 90% of time.
Thank you for testing and sharing your screen shot.
I'll have to take a long look at all the other websites I routinely visit in Firefox to see if they have similar issues. Yeah, it's worth checking your monitor as well to lower the contrast/brightness settings which are often set too high on default.
So far looking at other websites they all have the same attributes of excessive borders, etc. using Firefox. Too bad, as I suspect Mozilla could fix such things if they really wanted to. Probably the vendor of this forum, Xenforo as well. Though there are also developers out there that fundamentally take offense at users being able to alter the colors of their websites. A position I once held as a former website designer.
And then there is the intention of Google to totally control such things and exclusively set any design standards given their present domination of the browser market. That it's "Google Chrome's way or the highway".
I'm fine with Brave's use of the Chrome engine but with
suped-up privacy features that Google has no intention of ever using. I'll take privacy over dark mode for sure. In the meantime one of the simplest things to do is to consider
reducing the contrast and brightness of one's monitor.