Font header size problem

Hi,
I have a problem when changing / wanting to change the font size in the “Astrid” theme in the “Header text” and “Header small text” sections. After entering my text in both sections, I go to the font adjustment view -> “H3 font size” / “H4 font size” I change from the standard size to, in the order “36” and “46” save the sketch and go to the preview page and surprise … The font size has not changed, it has been saved but didn’t affect on page. When I go back to the settings, my values are saved but only after trying to change the font size, it adjusts to the value again, but again after saving the sketch, the saved value is not applied in preview, why? Of course, I also changed the font size constants in the “style.css” file, but this change does not affect the font size on page also, please help !? Any hint?

P.S.
I didn’t paste the link to the site because I got so confused with the changes that I did, so I get rid of the whole theme and wrote here for help (: