Hi @loraincray
Try this instead,
@media screen and (max-width: 768px) {
h4.entry-title {font-size: 14px !important;}
}
That is for mobile phones and tablets only.
If you want to reduce it for all devices, edit the font-size on line 51 of the style.css file by going to Appearance > Editor.
Then find h4.entry-title
Hope that fixes the issue.