an other issue in the new ff 143 theme

### Guidelines

- [x] I have read [how to report a new issue](https://github.com/Aris-t2/CustomCSSforFx/issues/4)
- [x] I have used the [latest release](https://github.com/Aris-t2/CustomCSSforFx/releases/latest)
- [x] I have set the `toolkit.legacyUserProfileCustomizations.stylesheets` in `about:config` to `true`

### Does the issue occur without any files inside /chrome/ folder?

Yes

### Description of the Issue

this is another issue with latest ff 143 see these pictures:
https://postimg.cc/ZWm188vq
and this:
https://postimg.cc/232bRGms
how to rehave fastforward and rewind buttons in solid grey theme?
as happened with old firefox 56.0.2 and waterfox classic
thxs in adv
cheers

### System information

- OS & OS version: win 10 home64
- DPI/HiDPI/scaling value, if not 100% (e.g. 125%, 150%...):
- Firefox version: 143
- Firefox theme (e.g. default, build in light/dark, external theme + link): default

Start by reviewing the linked screenshots and the current solid grey theme CSS in the repository, then reproduce the toolbar in Firefox 143 with the reported settings. Trace how the fast-forward and rewind buttons are styled or hidden and compare the result with the described Firefox 56.0.2 appearance. Done means both buttons are visible and match the solid grey theme.

Written by the indexing model from the issue text.