Switching from Classic to Modern Player

We want to switch to using the Modern player rather than the classic.

However, we have an issue.  The Classic player includes a border around the content, we've used our own buttons for navigation that on the edge of the screen area.

Within the Classic Player these are fine as there's a 15 pixel border, so the button is well away from the edge.  However, switch to Modern player and this border is gone.  This leaves the buttons right on the edge.

Question: Can I add a border to the Modern player?

Classic - HAS BORDER

Modern - NO BORDER