Increase Slider Headline & Subheadline

Does anyone know how to increase the headline and subheadline text on the slider? Can we do this in the font section of the customize or do we need css or is it impossible?

Hi, you can to add this code using custom css plugin. you can adjust the value of the font-size below:

.text-slider .maintitle {
    font-size: 70px;

.text-slider .subtitle {
    font-size: 50px;