jsFiddle is the perfect solution; it provides a custom environment (based on user selections) to test (or fiddle with) your JavaScript, HTML, and CSS ... page includes a line of buttons to use ...

Using CSS and JavaScript ... Right-click the HTML page you want to edit and select "Open With." Click your HTML editor in the list of programs. Load each image into a JavaScript array.

Not only that, but programming is also constantly in demand, so it's a reliable skill set to fall back on ... that will teach you how to code in HTML, CSS, JavaScript, Bootstrap, PHP, MySQL ...