Selector('#TableOfContents') : null;
    var toggleTocElem = document.getElementById('toggle-toc');
    var singleContentsElem = document.querySelector('.single__contents');
    var navbar = document.querySelector('.navbar');
    var tocFlexbox = document.querySelector('.toc__flexbox');
    var tocFlexboxOuter = document.querySelector('.toc__flexbox--outer');
    var expandContents = document.querySelectorAll('.expand__content');
    var boxContents = document.querySelectorAll('.box');
    var notAllowedTit