Vertically Align Slider Text on Splash Image

Is there a way to vertically align the slider text on the splash image? I see that depending on the screen size, the text moves around between the middle of the screen and the bottom of the screen. On my mobile phone it’s always in the middle. I’d like to make sure the whole thing (Header1 and Header2) are always on the bottom with a mobile phone, and maybe always on the bottom no matter the device. What Custom CSS code would take care of this? Thanks!