JS
(quick guide & example)
FULLSCREEN - ENTIRE PAGE document.documentElement. requestFullscreen();
FULLSCREEN - SINGLE SECTION document.getElementById("ID"). requestFullscreen();
EXIT FULL SCREEN document.exitFullscreen();
FULLSCREEN MODE CHANGED document.addEventListener( "fullscreenchange", () => { if (document.fullscreenElement ===null) { FULLSCREEN OFF } else { FULLSCREEN ON } });
FULLSCREEN MODE ERROR document.addEventListener( "fullscreenerror", () => { DO SOMETHING } );