<input type="checkbox" id="toggle" />
<label for="toggle" class="toggleWrapper">
    <div class="toggle"></div>
  </label>

<div class="background"></div>

<div class="footer">
  <a href="https://dribbble.com/shots/4707036-Switcher-XXXVIII" target="_blank">Designed by Oleg Frolov</a>
</div>

body {
  position: relative;
  margin: 0;
  padding: 0;
  height: 100vh;
  display: flex;
  align-items: center;
  justify-content: center;
  overflow: hidden;

  input {
    display: none;
  }

  .toggleWrapper {
    z-index: 3;
    display: flex;
    align-items: center;
    justify-content: center;
    cursor: pointer;
    transition: all .2s;
    width: 100px;
    height: 100px;
    border-radius: 50%;
    background-color: #fe4551;
    box-shadow: 0 20px 20px 0 rgba(#fe4551, 0.3);
    
    &:active {
      width: 95px;
      height: 95px;
      box-shadow: 0 15px 15px 0 rgba(#fe4551, 0.5);
      
      .toggle {
        height: 17px;
        width: 17px;
      }
    }
    
    .toggle {
      transition: all 0.2s ease-in-out;
      height: 20px;
      width: 20px;
      background-color: transparent;
      border: 10px solid #fff;
      border-radius: 50%;
      cursor: pointer;
      
      animation: red .7s linear forwards;
    }
  }

  .background {
    position: absolute;
    height: 100vh;
    width: 100vw;
    background-color: #fef5f4;
  }

  input:checked {
    & ~ .background {
      background-color: #f9faf7;
    }
    & + .toggleWrapper {
      background-color: #48e98a;
      box-shadow: 0 20px 20px 0 rgba(#48e98a, 0.3);
      
      &:active {
        box-shadow: 0 15px 15px 0 rgba(#48e98a, 0.5);
      }

      .toggle {
        width: 0;
        background-color: #fff;
        border-color: transparent;
        border-radius: 30px;
        animation: green .7s linear forwards !important;
      }
    }
  }
  
  .footer {
    font-family: "Lucida Sans Unicode", "Lucida Grande", sans-serif;
    position: absolute;
    display: flex;
    flex-direction: column;
    left: calc(50% - 96px);
    bottom: 0;
    font-style: italic;
    font-size: 12px;
    color: #212121;
    background-color: white;
    padding: 15px 20px;
    border-radius: 5px 5px 0 0;
    box-shadow: 0 5px 15px 0 rgba(0, 0, 0, 0.25);
    text-align: center;

    a {
      color: #222;
    }
  }
}

@keyframes red {
  0% {
    height: 30px;
    width: 0;
    border-width: 5px;
  }
  55% {
    height: 13px;
    width: 27px;
    border-width: 10px;
  }
  
  70% {
    height: 20px;
    width: 20px;
    border-width: 10px;
  }
  
  85% {
    height: 15px;
    width: 25px;
    border-width: 10px;
  }
  
  100% {
    height: 20px;
    width: 20px;
    border-width: 10px;
  }
}

@keyframes green {
  0% {
    height: 20px;
    width: 20px;
    border-width: 10px;
  }
  25%, 55%, 85% {
    height: 30px;
    width: 5px;
    border-width: 5px;
  }
  
  40%, 70%, 100% {
    height: 30px;
    width: 0;
    border-width: 5px;
  }
}

// Designed by Oleg Frolov
// https://dribbble.com/shots/4707036-Switcher-XXXVIII