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HTML

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CSS

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CSS Base

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JavaScript

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Babel includes JSX processing.

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HTML 

              
                
<!-- you may want to start your body element off with a class -->
<input id='toggle' class='toggle' type='checkbox'>
<label for='toggle'><span class='type'></span></label>

<h1>JS Style class toggler thingy</h1>

<p>This is a right of passage.</p>

<p>(but there are many different ways to do something like this - that we will talk about later)</p>
!

CSS 

              
                
body {
  font-family: sans-serif;
  color: var(--pe-purple);
  /* some things may be the default stuff like some padding? */
}

body .type::after {
  content: 'new style?';
}



body.hot {
  background-color: var(--pe-red);
  color: var(--pe-yellow);
}

body.hot .type::after {
  content: 'toggle to hot';
}



body.cold {
  background-color: var(--pe-cyan);
  color: var(--pe-blue-dark);
}

body.cold .type::after {
  content: 'toggle to cold';
}


/* one of these could surely be the default - intead of having a neutral to start out with */
!

JS 

              
                
// search the compiled HTML document (document object model) DOM
// understand a few elements
var body = document.querySelector('body');
var toggle = document.querySelector('.toggle');

// define the action
function toggleStyles(event) {
  if (event.target.checked) {
    //alert('checked');
    body.classList.remove('hot');
    body.classList.add('cold');
  } else {
    //alert('not');
    body.classList.remove('cold');
    body.classList.add('hot');
  }
} // a bit naive - because what if there are 30 styles! but totally normal to start the process

// use the action when the toggle is clicked
toggle.addEventListener('click', toggleStyles);
!
999px

Console