JSFiddle - React, Tailwind, and code Playground

HTML

<div id="navigation"></div>

JavaScript

var navigation = '<div class="container">'
navigation += '<a href="index.html"><img src="homeicon.jpg" width="50" alt="Home"></a>'
navigation += '<div class="redhover">'
navigation += '<div class="dropdown">'
navigation += '<button class="dropbtn">GCSEs</button>'
navigation += '<div class="dropdown-content">'
navigation += '<a href="chemistry.html">Chemistry</a>'
navigation += '<a href="biology.html">Biology</a>'
navigation += '</div>'
navigation += '</div>'
navigation += '<div class="dropdown">'
navigation += '<button class="dropbtn">A-Levels</button>'
navigation += '<div class="dropdown-content">'
navigation += '<a href="chemistry.html">Chemistry</a>'
navigation += '<a href="biology.html">Biology</a>'
navigation += '</div>'
navigation += '</div>'
navigation += '<div class="dropdown">'
navigation += '<button class="dropbtn">University</button>'
navigation += '<div class="dropdown-content">'
navigation += '<a href="chemistry.html">Telecommunications</a>'
navigation += '<a href="biology.html">Electronic Engineering</a>'
navigation += '</div>'
navigation += '</div>'
navigation += '<div class="dropdown">'
navigation += '<button class="dropbtn">More</button>'
navigation += '<div class="dropdown-content">'
navigation += '<a href="biology.html">About me</a>'
navigation += '<a href="https://www.youtube.com/channel/">Youtube</a>'
navigation += '</div>'
navigation += '</div>'
navigation += '</div>'
navigation += '</div>'

document.getElementById("navigation").innerHTML = navigation;