How to write CSS in AI form output?

Hi! Have a look here: https://meowapps.com/how-to-customize-css-wordpress/ ?? Don’t write CSS directly in the output. Style the input.

It is a little difficult for me study it, In fact, I just want change the output tile, the color is dark and size is too big, I try to write such css, but it seems not work:

title h2 {
font-size: 25px;
color: #00ff00;
}

Do you have the link to your chatbot?

This is one of my chatbot, I use it make article

https://www.metatyphon.com/articleassistant2/