themes/main_theme.tres is the project theme. It holds Godot's default look for
every control type the game uses, plus named styles for the game's own look
(popups, the background, spacers, list rows, title and text sizes, highlights)
and a palette for the popup dimming. Scenes and scripts name these styles
instead of setting colours, sizes or style boxes, and the five old theme files
are gone. themes/README.md explains the styles and how to make a new theme.
The screenshot tour now uses the real character pictures, so the layout
baseline is taken again. Screenshots are pixel-identical to before, and
test_theme.gd checks that the look stays in the theme.
The quiz (song, playlist, players, music player and the popups opened from
it) moves into Quiz.tscn and the top panel into TopBar.tscn. The main window
keeps only the top bar, the quiz and the popups opened from the top bar, so
other views can be added next to the quiz later. Every node keeps its place
on screen.
Screenshots of every UI state before and after are pixel-identical, and a
layout test checks each node against a baseline taken before the split.
Sansan