x
<html><title>W3.JS</title><link rel="stylesheet" href="https://www.w3schools.com/w3css/4/w3.css"><script src="https://www.w3schools.com/lib/w3.js"></script><body><div class="w3-container"><p><button class="w3-btn w3-green" onclick="w3.hide('p')">Hide all p elements</button></p><div class="w3-panel w3-green"><h2>London</h2><p>London is the capital city of England.</p><p>It is the most populous city in the United Kingdom.</p><p>Population over 13 million inhabitants.</p></div></div></body></html>