A TamperMonkey script that hides the Reddit post list "underlay" when you open a post thread

main.js

// ==UserScript==
// @name         RedditHider
// @namespace    https://www.reddit.com
// @version      0.2
// @description  Hide Reddit main page when a thread is opened
// @author       Ricky Cook
// @include      https://www.reddit.com/*
// @grant        none
// @updateURL    https://gist.githubusercontent.com/RickyCook/72fc3a971a638b10864d98ffe3fc2ffd/raw/main.js
// ==/UserScript==

(function() {
    var toggleEls = []
    function isOverlay() {
        return document.location.pathname.startsWith('/r/')
    }
    function underlayEls() {
        var wrapper = document.getElementsByClassName('m-commentspage')[0]
        if (!wrapper) return toggleEls
        return Array.from(wrapper.parentElement.children).filter(function(el) {
            if (el === wrapper) return false
            if (el.tagName.toUpperCase() !== 'DIV') return false
            return true
        })
    }
    function ensureState(hidden) {
        toggleEls = underlayEls()
        for (var el of toggleEls) {
            el.style.visibility = hidden ? 'hidden' : null
        }
    }

    var lastPath = null, lastHidden = null
    setInterval(function() {
        if (document.location.pathname === lastPath) return
        console.log('changed location')
        lastPath = document.location.pathname
        ensureState(isOverlay())
    }, 100)
})()