Enhancement
A select HTML element has no CSS class. This ensures that global CSS selectors are written. This leads to conflicts when plugins etc. are introduced into the code that have their own CSS styles for their select elements.
Improvement
Include a CSS class in the SelectControl when drawing and adapt all CSS files.
Test
Start the application and check all select fields. Check that the class is present in every select element and that they have the same design as before the changes.