Slider positioning

[ian-p-cooke]

i can show some code when i get home but i have a simple enough problem to replicate: when i add a slider to the ui it doesn't center or justify no matter what i've tried. the closest i've come is that with add_sized() it moves towards the center and reacts to window resizing but it's not actually centered.

any ideas as to how to do that? i can center buttons and other elements fine. just not sliders.