#7109 was added in to make Plotly.js work better in strict CSP environments (specifically, ones which disallow inline CSS); however, it seems some of that work was broken by the migration to ESBuild.

For example, we no longer produce a separateplotly.css file (see recent comments on that PR).

@camdecoster recently added#7527 which makes it easier to test different CSPs in the devtools.

There's at least one obvious issue when inline styles are disallowed, which is that the modebar button styling is completely broken: