[Feature Request]: configure text size separately from thumbnail size

[aleksejrs]

Guidelines

• [X] I have searched the issue tracker for open and closed issues that are similar to the feature request I want to file, without success.
• [X] I have searched the documentation for information that matches the description of the feature request I want to file, without success.
• [X] This issue contains only one feature request.

Problem Description

FreeTube has only a full page zoom, which assumes that there is an optimal relation between the fonts and thumbnail size that works for all or most users. As a result, thumbnails in a grid of playlists are huge and annoying compared to their captions, and zooming does nothing to change that. https://github.com/FreeTubeApp/FreeTube/issues/4605

Proposed Solution

Separate the text and thumbnail size controls, at least in the settings. Since everything is controlled by CSS, it should be easy to specify a base font size in pixels and a thumbnail size in pixels or ms or ns. Themes could be made external CSS files, so the user could specify the sizes for specific contexts like the playlist windows.

Alternatives Considered

Add buttons to +/- font size and thumbnails on the top panel.

Issue Labels

ease of use improvement, visual improvement

Additional Information

No response

[kommunarr]

This is directly related to a problem of inaccessibility with FreeTube's current design / messiness with our current code that would be great if it could be fixed. The main problem is that we're using absolute pixel units rather than defining everything in terms of rem, and not using set CSS variables corresponding to different size classifications. As a result, we have lots of arbitrary pixel-specific values in different places that are hard to keep track of, and increasing the root font size would have minimal effect currently. Whichever contributor on here who wants to fix this one will most likely have to implement this structural change in tandem.

[ACR-Jeff]

Here is just an example of what I am looking at with the UI Scaled at 100% The top half of that image is the video description area, Bottom obviously is the comments, Scaling the UI to get a decent font size in comments would scale everything on the UI far to large for normal use.