Draft: Add Matcha CSS and clean up HTML/CSS some

[momijizukamori]

Not ready for merge yet (still needs dark mode images and I kind of want to throw a minimal background on the page body), but up for preview.

• Standardized labels (capitalized, with a trailing : when input field is after the label)
• Added Matcha CSS with some tweaks
• Updated HTML to add Matcha classes and remove now-unnecessary elements
• Updated a bunch of absolute positioning of elements to use flex instead

[github-actions]

PR Preview Action v1.6.0
Preview removed because the pull request was closed.
2025-05-13 19:05 UTC

[acestronautical]

I like Matcha CSS, but the UI probably needs a bigger facelift than this.

I've been wondering if a style similar to https://acestronautical.github.io/bookcover-js/ would make sense.

Except have three panels. |page/sig info panel| |pdf preview in middle| |settings pane on left|

[momijizukamori]

I think that would be too much info, too wide - I expect to get pushback on the width of this version honestly, even though I think it's a fairly reasonable content area.

I agree that we do still need to consider some bigger changes, UI-wise, but those are going to take a bunch of discussing, and in the meantime this is kind of a general sprucing-up and accessibility improvement.

[daun]

This is great! I'm currently using the updated version from the PR preview of this branch over the current live version and am liking it very much :)