Off-canvas close button not working

I have copied and pasted the example code from your site for the Close button that you can add to the Off-Canvas menu. But for some reason it is not working. I created a codepen here:

The menu button to open the off-canvas menu works just fine and also can close it. But I was wanting to use the overlap menu (data-transition=“overlap”) but then on mobile the menu button would be hidden, so I would need a close button. But I just cannot figure out why it’s not working.

The close button z-index is below the anchor links.

If you add a z-index to the .close-button class it works:

Code Pen:

.close-button, .close-button.medium {

Thanks so much, I somehow missed this response.