input(type='checkbox', id='play')
label.play(for='play') Animation

.container background: white !important;
View Compiled
html, body
  background: #111
  font-family: sans-serif

#play
  display: none

.play
  padding: 1rem
  color: white
  background: #666
  display: inline-block
  border-radius: 2px
  margin: 1rem
  cursor: pointer
  user-select: none

      

#play:checked
  ~ .play
    background: seagreen
  ~ .container
    animation: scenario 0s forwards
  
.container
  display: inline-block
  padding: 1rem
  background: white !important
  margin: 1rem
    
    
@keyframes scenario
  to
    background: #358

External CSS

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External JavaScript

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