Hi there,
Thanks for reaching out to us.
Did you mean this portion? https://prnt.sc/tbeNL7AK-nn-
Then please use the following code in your custom CSS:
body.com-content.view-article .page-header h1 {
font-size: 70px;
}
You can change the font size as per your need in the above code:)
Note: Path towards custom CSS(Joomla 4): System>Site Templates Styles> Click on your current default template name then choose Template Options. Then find custom CSS within the custom code.
https://prnt.sc/5mBuSRh907N3
https://prnt.sc/ooiq-lkMEXr_
https://prnt.sc/nunlX-f5AhK1
Best Regards