How to change size of specific font for mobile?

Can I please get some help? I need to change this font size on mobile because it looks huge. I don't want to mess up with other font, tho, so I'm not sure whether I need specific code? Thanks a lot!! 

Can you share link to this page? We can check easier

21 hours ago, tuanphan said:

Can you share link to this page? We can check easier

https://www.festifyrentals.com/blog/blog-post-title-one-ce7zg only on mobile it looks huge

7 hours ago, tuanphan said:

You can use this code to Website > Website Tools > Custom CSS

/* blog title on mobile */
@media screen and (max-width:767px) {
div.blog-item-title h1 {
    font-size: 30px !important;
}
}

 

worked out! thank you so much