Hi @chrissy,
Sorry for the incomplete answer. Master Slider is just one of the options.
You can enable or disable the buttons in the Admin Dashboard using Integral Options > Welcome section.
Styles of the buttons are located in the style.css file on lines 237-295, I highly recommend you to overwrite those rules at Appearance > Customize > Additional CSS, instead of just changing it in the style.css.
You can also edit code of the buttons in the sections/hero.php file.
Cheers,
Piotrek
