Calendar Block Mobile-Version Event Thumbnail Does Not Show

Site URL: https://www.citystringensemble.com

Hi, the MOBILE version of my homepage does not show the event thumbnail pictures in the calendar block. Instead, it's a difficult to see grey colour as my page background is black. The event thumbnail shows on the desktop version of the site and is working perfectly.

I have researched for help on the forum and have found a custom code to change the colour of event dates on the mobile calendar to gold which is much clearer for now, but I would like these to be the event thumbnail images instead.

Does anyone know of a way to have the thumbnails show up in the calendar block on mobile?

The site is www.citystringensemble.com (scroll down for the calendar block in question)

Thank you for your help!

I see you solved with this CSS code?

@media screen and (max-width:640px) {
td.has-event {
    background: gold !important;
}
}

I am also wanting my event calendar to show the thumbnail on mobile