JSFiddle - React, Tailwind, and code Playground

HTML

<button>
    Click me to turn the lights
</button>

<img src="http://myworldfacts.com/wp-content/uploads/2015/02/Horse-22.jpg" width="200">

CSS

body {
    background: black;
}

img {
    display: block;
    margin-top: 50px;
}

JavaScript

var state = 'off';

$('button').click(function(){
    
    if(state == 'off'){
      // turn on the lights
      $('body').css('background','white');
      state = 'on';
    }
    
    else {
      // turn off the lights
      $('body').css('background','black');
      state = 'off';
    }    
    
});