Post titles too big when viewing on mobile

Hi, please could someone help me, my post titles are way too big when viewed on mobile, they’re fine on desktop or tablet but absolutely huge on mobile. I have already tried the Custom CSS below:

/* Adjust the title font size for mobile devices / @media (max-width: 767px) { .post-title { font-size: 18px; / You can adjust this value to your preference */
}
}

I made sure to change the .post-title to my themes CSS class and I purged all cache’s and regenerated CSS files in elementor and it still hasn’t worked.

My Theme is Ocean WP.

I have tried everything I can find online without success so if anyone could help that would be greatly appreciated!

Thank you!!