Hello, @Wade Yang,
1- I think you didn’t read my previous message. I explain step by step process for how to use the uber menu. Please check my message again and try to follow the steps.
2- In order to solve your issue simply go to the Dashboard >> XStore >> Theme Settings >> Theme Custom CSS >> Global and then paste the below code at the bottom of the CSS box there.
.single-product form.cart table.variations th.label label{font-size:30px !important;}
.single-product ul.st-swatch-size-large li.type-label span{font-size:30px !important;}
Then save settings and check back to your site after clearing the browser cache.
Note: In the above code the word “30” is the size you can change it with the size you want.
Regards 8Themes Team.