Menu background on mobile

I purchased the pro version. I changed the main menu background to a light gray with blue letters. When viewed on mobile phone, background is still dark gray so menu names in blue are hard to read. How can I fix this? Can view here

Thank you!

that was because the stylesheet for mobile display are not set, you have to using media query to enable it. Try to add this code below, please use custom css plugin to add the code, so your stylesheet will not replaced when you update your theme:

@media screen and (max-width: 991px){
 .has-banner .main-navigation {
   background-color: rgba(232,232,232,0.8);

Fixed! Thanks for the fast response!