Help to customize blog title in web and mobile version

I add the code below to customize text in the blog post. The desktop version works well, but the mobile looks bad. The space between the text is too big. How can I fixed the mobile version without affect the desktop version?

/* Blog title*/
h1.blog-title a {
    font-size: 25px;
  line-height: 30px;
    font-weight: 500 !important;
}

thanks! 

share site url pls

8 hours ago, E-W said:

BUT, if you use rem instead of px the line height will be responsive to the device. 

I agree, setting the line height to 1.2em instead of 30px will keep the line height responsive to the text size changes on mobile.

Thanks you so much!
 I use the line-height: 1.2em; and look much better now 🙂