You don’t need to find the spot in the original stylesheet ??
You can target an element like .entry-title by adding additonal CSS in a couple of ways:
If you’re building a child theme (this is preferable to modifying the original theme directly, because it protects your edits from being erased in an update), you can put the new CSS right in the child theme style.css file – it doesn’t need all of the original theme’s CSS, just the styles you want to add or change.
Another (simpler) options is to use the Additional CSS panel in the Customizer (assuming you’re running at least WordPress 4.7) or with something like the Jetpack Plugin using the Custom CSS Module.
In either case, you can change the size of page titles with this snippet:
.entry-title {
font-size: 32px;
}
Let me know if I can be of any more help!
