OnTake / Youtube Custom Theme v3

// ==UserScript==
// @name         Youtube Custom Theme v3
// @namespace    https://xe0f9.github.io/
// @version      2021.3.31
// @description  Maybe
// @author       Louis Dalibard
// @match        https://www.youtube.com/*
// @grant        none
// @copyright 2020, OnTake (https://openuserjs.org/users/OnTake)
// @license MIT
// ==/UserScript==

//Customisation variables

//Customisation Text
const textfont = "\"Exo 2\""; // Goldman ; Roboto Mono ; Noto Sans ; Open Sans ; Roboto ; Ubuntu ; Space Grotesk ; Noto Sans JP ; Source Sans Pro ; Anton ; Libre Baskerville ; Exo 2 ; Advent Pro

//Customisation colors

//Customisation misc
const cornerradius = "10px";
const cornerradiussmall = "10px";

function setcss() {
    var csselement = document.createElement("style");
    csselement.className = "youtube-skin-css";
    // CSS Imports
    csselement.innerHTML = "@import url('https://fonts.googleapis.com/css2?family=Goldman&family=Noto+Sans&family=Open+Sans&family=Roboto&family=Roboto+Mono&family=Space+Grotesk&family=Ubuntu&family=Noto+Sans+JP&family=Source+Sans+Pro&family=Anton&family=Libre+Baskerville&family=Exo+2&family=Advent+Pro&display=swap');";
    // Set Body CSS
    csselement.innerHTML += "body{"
    csselement.innerHTML += "font-family:" + textfont + ";"
    csselement.innerHTML += "}";
    // Set Searchbar CSS
    csselement.innerHTML += "#search-input.ytd-searchbox-spt input {"
    csselement.innerHTML += "font-family:" + textfont + ";"
    csselement.innerHTML += "}";
    // Set Video Player CSS
    csselement.innerHTML += ".html5-video-player {"
    csselement.innerHTML += "font-family:" + textfont + ";"
    csselement.innerHTML += "}";
    // Set Captions CSS
    csselement.innerHTML += ".ytp-caption-segment {"
    csselement.innerHTML += "font-family:" + textfont + " !important;"
    csselement.innerHTML += "}";
    // Variables
    let root = document.documentElement;
    root.style.setProperty('--paper-font-subhead_-_font-family', textfont);
    //root.style.setProperty('--dark-primary-color', darkprimarycolor);
    // Add stylesheet to HTML document
    document.head.appendChild(csselement);
}

(function() {
    'use strict';
    //Set CSS
    setcss();
})();