To dstillman,

This no longer occurs in this mode.
To rule out issues caused by add-ons, I removed all of them, yet the problem persists.

While restarting in Troubleshooting Mode ensures proper display, I rely on the conveniences provided by add-ons and cannot continue using Zotero in this mode. My current plan is to proceed with caution by downgrading to Zotero 6, but this will also prevent my add-ons from updating to their latest versions.

Finally, I began to wonder if the problem lay with my computer – perhaps a software or display issue? After all, Zotero was working fine on my other machines.

The following two images show the plugin interface after removing all plugins and the main page, which still has issues.

https://s3.amazonaws.com/zotero.org/images/forums/u10796878/s2zfmmialsvg1zcjfwyb.png
https://s3.amazonaws.com/zotero.org/images/forums/u10796878/9awsvqbvvv1740hdnkwq.png

What kind of computer and graphics card? I'd guess that it's related to your graphics driver. If you have a control panel for your graphics card, try setting it to treat Zotero the same as it treats Firefox.

No, it wouldn't be about GPU performance. Zotero runs fine on computers with integrated graphics cards (and much older computers than yours).

You still might have some sort of control panel for the integrated graphics card. I'd check there to see if you can set any sort of exclusion or special settings for Zotero.

Beyond that, I suspect disabled setting layers.acceleration.disabled to true in the Config Editor of the Zotero settings and restarting Zotero would fix this, but that would slow down Zotero's performance and should only be done if you can't figure out another solution.