CSS to change the font size and line spacing inside the Slide

Hi. How can you change the font size, line spacing and slide size attributes? of the presentation made by the Strong Testimonial slide.

In the link, attached, in which I am testing… I successfully managed to adjust it at the bottom… But at the top of the page, with the slide, although it works well, it takes up a lot of screen space. It doesn’t look pretty.

I have tested the CSS in the appearance area of the astra theme with the Elementor layout designer.

I clarify that I am just learning CSS.

Thank you

stayfreee

The page I need help with: [log in to see the link]