hi, thank you for your answer.
It doesnt work!
I’m using a child theme, that i don’t loose my settings after a theme update.
So i created a folder enfold-child/css/custom.css:

/* General Custom CSS */
/*
Desktop Styles
================================================== */
/* Note: Add new css to the media query below that you want to only effect the desktop view of your site */

@media only screen and (min-width: 768px) {
  /* Add your Desktop Styles here */

    #top div div.product .woocommerce-tabs ul.tabs li a {
    padding: 9px 20px 10px 20px;

}
}
/*
Mobile Styles
================================================== */
/* Note: Add new css to the media query below that you want to only effect the Mobile and Tablet Portrait view */

@media only screen and (max-width: 767px) {
  /* Add your Mobile Styles here */

}

Can I don’t use the style.css in the main child theme folder?

And how can I use Quick CSS?

Thank you for your answers.
Regards
Laenggi