beta version (5.1.1130.26)

[tamer]

Thanks, the font has changed in the settings, but not in the bookmarks. Does the font change in your bookmarks as well?

Yes, it does. Try to set the background or clearly distinguishable font to verify it. Try this one:

Code:

settings-ui,
bookmarks-app,
downloads-manager,
extensions-manager {
    font-family: 'Comic Sans MS';
    background: red;
}