Userscript for Mangaupdates - reduces font size and padding

// ==UserScript==
// @name        Mangaupdates smaller font size & padding
// @description Reduces the font size from 14 to 12 and reduces padding between list entries
// @match       *://www.mangaupdates.com/*
// @version     1.0
// @grant       none
// ==/UserScript==

function addGlobalStyle(css) {
var head, style;
head = document.getElementsByTagName('head')[0];
if (!head) { return; }
style = document.createElement('style');
style.type = 'text/css';
style.innerHTML = css;
head.appendChild(style);
}

addGlobalStyle('html { font-size: 12px ! important; }');
addGlobalStyle('.p-1 { padding: 0.1rem ! important; }');