Font Size

Yes. Please provide a link to a page on your site where we can see this. Thanks. Note: Your link will be public and we will not later remove it.

https://jualayamhias.com/sejarah-dan-asal-usul-ayam-serama/

Thank you for concern, and this is the link

This ups the font size by 25% inside the post:

.post-content-inner {
    font-size: 125%;
}

To add or override CSS: use the “Additional CSS” option in the customizer. https://codex.www.ads-software.com/CSS#Custom_CSS_in_WordPress

Learn to use the Chrome Developer Tools or Firefox Developer Tools to help you see and test changes to your CSS.