You can enlarge the main window by clicking on the double arrows on the black bar at the bottom of the video screen. This black bar allows you to press pause and adjust the volume of the video. The double arrows can be found on the far right of the black bar.
Press the “Esc” key to reduce the main window to normal size.
You can find a video explaining how to use the Cool Kids site under the “HELP” tab on the Main Menu.