Hi Marko,
1. To reduce the size of your title and tagline on mobile:
@media (max-width: 768px) {
.main-title {
font-size: 30px;
}
.site-description {
font-size: 20px;
}
}
2. To change the font size of the H1 tags:
@media (max-width: 768px) {
h1 {
font-size: 30px;
}
}
Adding CSS: https://generatepress.com/knowledgebase/adding-css/
3. What plugin are you using for the sticky menu? I suggest using our Menu Plus add-on as it’s optimized for GP and does the same thing 🙂