Better Youtube Theatre Mode

Enlarges the media player to fill the entire screen with theatre mode.

You will need to install an extension such as Tampermonkey, Greasemonkey or Violentmonkey to install this script.

You will need to install an extension such as Tampermonkey or Violentmonkey to install this script.

You will need to install an extension such as Tampermonkey or Violentmonkey to install this script.

You will need to install an extension such as Tampermonkey or Userscripts to install this script.

You will need to install an extension such as Tampermonkey to install this script.

You will need to install a user script manager extension to install this script.

(I already have a user script manager, let me install it!)

You will need to install an extension such as Stylus to install this style.

You will need to install an extension such as Stylus to install this style.

You will need to install an extension such as Stylus to install this style.

You will need to install a user style manager extension to install this style.

You will need to install a user style manager extension to install this style.

You will need to install a user style manager extension to install this style.

(I already have a user style manager, let me install it!)

// ==UserScript==
// @name         Better Youtube Theatre Mode
// @namespace    http://tampermonkey.net/
// @version      1.7
// @description  Enlarges the media player to fill the entire screen with theatre mode.
// @author       shanish_ @discord
// @match        https://www.youtube.com/*
// @icon         https://www.google.com/s2/favicons?domain=youtube.com
// @grant        none
// @run-at       document-start
// ==/UserScript==


/**

A simple script to fix youtube's CSS to set the containers height to 100vh - navbar height

**/

// Injects CSS into the header of the document.
function addStyle(styleText){
    let s = document.createElement('style')
    s.setAttribute("id", "youtubetheater");
    s.appendChild(document.createTextNode(styleText))
    document.getElementsByTagName('head')[0].appendChild(s)
}

// I do not like this but youtube is a single page app and they may delete the style sheet after it in injected.
// To ensure it stays, it will check every second but this is nothing to performance.
setInterval(
loadCss,1000)

function loadCss() {
    'use strict';
    if(document.getElementById("youtubetheater")){return;}

        // Applys css to the page to resize the media player to the entire screen.
    addStyle(`


:fullscreen #player-full-bleed-container,:fullscreen #full-bleed-container {
max-height: calc(100vh) !important;
}
:has([is-theater-mode]) #player-full-bleed-container,:has([is-theater-mode]) #full-bleed-container{
    max-height:calc(100vh - 52px)!important;
    height:100vh!important;
}

   `)
};