During a course, I have to scroll down to see the audio controls.

Try switching your browser to full-screen mode or simply hide some of the toolbars so you can see more of the web page. Here's how to enable full-screen mode in most browsers:

Chrome, Edge Firefox & Internet Explorer: F11
Safari: Control-Command-F

During a class, you can also click on the HELP (?) button and then click "I Need To Adjust The Display Size". Then you can adjust the zoom level of the slide.