WordPress Text Color Issue: Desktop vs. Mobile

Hello,

The text colors on my website appear to be opposites when opening my site on desktop vs. mobile. I’m working on building my WordPress site for mobile, but I keep running into this issue. When the text is black on the desktop, it appears white on mobile; when I change the text to white and save on desktop, the text turns black on mobile. I would like them to be the same color.

Additionally, how do I make changes to the mobile version of the site without interfering with the layout of the desktop version? I would like to edit it separately from the desktop version.

Please let me know if anyone can help! Would love to get this fixed ASAP. Thanks!

The page I need help with: [log in to see the link]