SUMMARY Breeze button style for hover state currently only highlight border of the button. This looks a bit strange with flat toolbar buttons and plasmashell ui elements. I suggest to add background highlight to them also similarly how it looks when button is clicked. This will make button hover selection prettier and more consistent with other ui elements like application launcher app hover style. STEPS TO REPRODUCE 1. 2. 3. OBSERVED RESULT EXPECTED RESULT SOFTWARE/OS VERSIONS Windows: macOS: Linux/KDE Plasma: (available in About System) KDE Plasma Version: KDE Frameworks Version: Qt Version: ADDITIONAL INFORMATION
At the moment I'm afraid this style is intentional. There's no need for consistency between buttons and list items because they aren't the same kind of UI element. In general things that aren't the same don't need to look the same, and if they do, it can even be confusing. You're welcome to use a different theme if you have different aesthetic preferences.