Hey @core365,
I’ll show you some custom CSS to achieve a responsive tab behavior but please note that it is to our understanding that you will learn Flexbox and continue to work on the custom CSS to achieve what you need.
I’d recommend that you first see the result or the behavior the custom CSS would be doing. Please watch this screencast: https://youtu.be/hiudVkXn_KE
The custom CSS used is this:
@media (max-width:640px) {
.x-tabs-list ul {
flex-wrap: wrap;
}
.x-tabs-list li {
flex: 1 1 auto;
}
}
Add it to your page’s Content CSS or Theme Options > CSS for global application.
You can change auto
in the code to a fixed value to get a uniform size.

Hope that helps and thank you for understanding.