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HTML 

              
                <input type="button" class="switch active" onclick="this.classList.toggle('active'); alert('Turn this button '+(this.classList.contains('active')?'on':'off'));" value="Toggle me" title="Toggle me" />

<input type="button" class="switch" onclick="this.classList.toggle('active'); alert('Turn this button '+(this.classList.contains('active')?'on':'off'));" value="Toggle me" title="Toggle me" />

<input type="button" class="switch" onclick="this.classList.toggle('active'); alert('Turn this button '+(this.classList.contains('active')?'on':'off'));" value="Toggle me" title="Toggle me" disabled />

<input type="button" class="switch vertical" onclick="this.classList.toggle('active'); alert('Turn this button '+(this.classList.contains('active')?'on':'off'));" value="Toggle me" title="Toggle me" />
!

CSS 

              
                input.switch {
  width: 0;
  overflow: hidden;
  padding-left: 68px;
  background: #c5c5c5 url() 2px center / auto 32px no-repeat;
  border-radius: 18px;
  border: 0;
  color: transparent;
  height: 36px;
  transition: all 0.3s ease-in-out;
}
input.switch:not([disabled]) {cursor: pointer;}
input.switch.active {
  background-color: #8ab82e;
  background-position: calc(100% - 2px) center;
}
input.switch.vertical {transform: rotate(-90deg);}









/* base64 encoded circle svgs */
input.switch {
  background-image: url('data:image/svg+xml;base64,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');
}
input.switch[disabled] {
  background-image: url('data:image/svg+xml;base64,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');
}



/* for presentation only */
html, body {height: 100%;}
body {display: flex; justify-content: center; align-items: center; flex-direction: column; gap: 30px;}
input.switch.vertical {margin-top: 15px;}
!

JS 

              
                /* 

Hey Adam, here is a(nother) remake of one of your GUI challenges. I used a button instead of a checkbox (input with type 'button' and class 'switch'). I see a switch as a button with a state. A checkbox requires a save action, while a button fires the action immediately. I think most people want the latter (nowadays). The state is stored in the class (for brevity), but could also be stored in a data property (nicer). These buttons have high accessibility by default and are super easy to use: one HTML element and a few lines of CSS is all there is to it! Try tabbing on these ones! I am looking forward to your next GUI challenge. Have a great day!

https://web.dev/shows/gui-challenges/_KqccADghcA/

*/
!
999px

Console