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HTML

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CSS

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JavaScript

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HTML 

              
                <h2>Toggle Switch</h2>
<p id="version">Last updated in <a href="https://cdn.watermarkinsights.com/css/rc/1.2/wm-global.css" target="blank">1.2.0</a></p>
<p>Toggle switches may be in one of two positions, usually on or off. Behind the scenes they are marked up as checkboxes.</p>
<p>The HTML structure consists of a container <code>label</code> element with an <code>input</code> followed by a corresponding element with the accessible name and an optional element with text for the state, e.g. ON/OFF. If using the state, you will need to write a script for the onchange event.</p>
<label class="switch-toggle" for="toggle">
  <input type="checkbox" id="toggle">
  <div class="togglelabel">Label for toggle</div>
  <div class="toggletext">off</div>
</label>

<h3>Previous Implementation</h3>
<p>As with the implementation above, our original implementation uses the label to create the visual switch. However, we would add a second label to associate an accessible name with the checkbox. According to web.dev this actually <em>created</em> an accessibility issue, and Lighthouse will flag it as a problem: </p>
<blockquote>If you unintentionally associate multiple labels with a single control, you'll create inconsistent behavior across browsers and assistive technologies: some will read the first label, some will read the last label, and others will read both labels.</blockquote>
<div class="toggle-switch">
  <input type="checkbox" id="oldtoggle">
  <label class="switchtoggle" for="oldtoggle" data-checked="ON"></label>
  <label for="oldtoggle">We shouldn't do this</label>
</div>
!

CSS 

              
                html, body {
  height: auto;
}
body {
  padding: 0 20px 40px;
  font-size: 14px;
}
h2 {
  font-size: 24px;
  font-weight: 600;
  margin-bottom: 0;
  
  &:not(:first-of-type) {
    margin-top: 32px;
  }
  
  + p {
    margin-top: 0;
  }
}
h3 {
  font-size: 22px;
  font-weight: 400;
  margin: 32px 0 0;
  
  + p {
    margin-top: 0;
  }
}

blockquote {
  margin-left: 0;
  padding-left: 20px;
  border-left: 4px solid #e9e7ec;
}

#version {
  font-style: italic;
}

.toggle-switch {
  border: none;
  margin-bottom: 24px;
  outline: 0;
  padding: 0;
  position: relative;
  -webkit-user-select: none;
  -moz-user-select: none;
  -ms-user-select: none;
  user-select: none;

  input {
    opacity: 0;
    padding: 0;
    position: absolute;
    clip: rect(0, 0, 0, 0);

    + .switchtoggle {
      border-radius: 56px;
      transition: left 0.15s ease-out;
      cursor: pointer;
      margin: 0;
      display: inline-block;
      vertical-align: baseline;
      color: transparent;
      background: rgba(255, 255, 255, 0.33);
      border: 1px solid #575195;
      width: 56px;
      height: 26px;
      position: relative;
      text-align: left;

      &:before {
        position: relative;
        content: attr(data-checked);
        border: none;
        background: none;
        width: 39px;
        height: 100%;
        color: var(--wmcolor-text, #4a4a4a);
        font-size: 12px;
        font-weight: bold;
        line-height: 24px;
        text-transform: uppercase;
        text-align: right;
        display: inline-block;
        left: 6px;
      }

      &:after {
        transition: left 0.15s ease-out;
        border-radius: 50%;
        border: 1px solid #575195;
        background: #ffffff;
        content: "\A0";
        display: block;
        position: absolute;
        top: 5px;
        left: 7px;
        width: 13px;
        height: 13px;
      }
    }

    &:checked + .switchtoggle {
      border-color: #575195;

      &:before {
        content: attr(data-checked);
        text-align: left;
        left: 6px;
      }

      &:after {
        left: 34px;
        background: #575195;
      }
    }

    &:disabled + .switchtoggle {
      cursor: default;
      border-color: #6b6b6b;

      &:after {
        display: inline-block;
        font: normal normal normal 24px/1 "Material Design Icons";
        font-size: inherit;
        text-rendering: auto;
        line-height: inherit;
        -webkit-font-smoothing: antialiased;
        -moz-osx-font-smoothing: grayscale;
        background: #6b6b6b;
        font: normal normal normal 24px/1 "Material Design Icons";
        content: "\f33e";
        color: #ffffff;
        font-size: 9px;
        padding-top: 2px;
        padding-right: 1px;
        padding-left: 1px;
      }
    }
  }

  label {
    margin-right: 5px;
    font-size: 12px;
  }

  .switchtoggle + label {
    margin-left: 5px;
    margin-right: 0;
  }
}
!

JS 

              
                const textcontainer = document.querySelector('.toggletext')
document.getElementById('toggle').addEventListener('change', c =>  c.target.checked ? textcontainer.innerHTML = 'on'
  : textcontainer.innerHTML = 'off'
  )
!
999px

Console