[defanor]

> I expect "Org mode is for keeping notes [...]" to take up about three lines. What's going wrong for you?

It takes 4 lines here, but the issue is with horizontal overflow: "planning" is in the end of the first line for me, and it's cut on the last "n" (with no horizontal scroll). Below that, "developed by many others." is cut on "h" in "others". That's in FF 68, where it's also aligned to the right side, while in FF 78 it is centered. All the other elements are centered in FF 68 too.

It moves to the left and becomes readable (i.e., all words are fully visible) when I remove font settings (org.css:32) and the --body-left ones, or if "display: flex" is disabled altogether, but not sure what's the exact issue. There's "overflow-x: hidden" in the CSS, which probably contributes to it.

Edit: apparently it's similar to the issue reported by john-aj here.