CSS code for colours not appearing in mobile site

Site URL: http://othevents.com

Hi! Need help! I have the dates shaded in green with a custom code. But the green is not showing up in the mobile version.  This is the code I used:
/* Dates colors (all) */
ul.itemlist.itemlist--iseventscollection {
  background: #6CD84E;

What else should I do?

I see green on mobile here. Do you still need help on this?

Also, I see some pages have very long content, you can add back to top button on mobile/tablet.

If you want this, I will give the back to top code.