FEM Loopstudios Landing Page

A lot of the underlying code was reused from a previous Frontend Mentor challenge, namely the Intro Section with Dropdown Navigation. I just made some changes, like in mobile mode, when the hamburger menu is clicked the menu drops down instead of sliding from the right. Therefore the logo and the 'x' close button will continue to be shown.

There is one thing that I couldn't solve for now. When in Firefox with the developer tools open, I get overflow warnings. Even when I completely removed the CSS stylesheet, it still gives me overflow warnings.

After thinking about it for a while, I did notice that some of the overflow warnings were blinking out when the element(s) that had them were visible in the window. If they've scrolled off up or down, and weren't visible anymore then the overflow warning would come back again. Is this how it should be?