.sound-toggle__button {
    animation-name: fade-in;
    animation-delay: 0s;
    animation-duration: .3s;
    animation-fill-mode: both;
    animation-timing-function: cubic-bezier(.165,.84,.44,1);
    height: 15px;
    width: 23px;
    opacity: 0;
    display: flex;
    align-items: flex-end;
    justify-content: space-between;
    border: 0;
    padding: 0;
    appearance: none;
    background: transparent;
  }

  .sound-btn{
    position: fixed;
    bottom: 4%;
    right: 6%;
    z-index: 2;
  }

  #bars, #bars-muted {
    height: 30px;
    left: 50%;
    margin: -30px 0 0 -20px;
    position: absolute;
    top: 50%;
    width: 40px;
  }

  #bars{
    display: none;
  }

  #bars-muted{
    display: block;
  }

  #bars:hover, #bars-muted:hover{
    cursor: pointer;
  }

  .bar-muted{
    background: #d5d5d5;
    bottom: 1px;
    height: 3px;
    position: absolute;
    width: 3px;
  }

  .bar-muted:nth-child(1)  { left: 1px; }
  .bar-muted:nth-child(2)  { left: 5px; }
  .bar-muted:nth-child(3)  { left: 9px; }
  .bar-muted:nth-child(4)  { left: 13px; }
  .bar-muted:nth-child(5)  { left: 17px; }
  .bar-muted:nth-child(6)  { left: 21px; }
  .bar-muted:nth-child(7)  { left: 25px; }
  .bar-muted:nth-child(8)  { left: 29px; }

  .bar {
    background: #d5d5d5;
    bottom: 1px;
    height: 3px;
    position: absolute;
    width: 3px;      
    animation: sound 0ms -800ms linear infinite alternate;
  }

  .bar:nth-child(1)  { left: 1px; animation-duration: 474ms; }
  .bar:nth-child(2)  { left: 5px; animation-duration: 433ms; }
  .bar:nth-child(3)  { left: 9px; animation-duration: 407ms; }
  .bar:nth-child(4)  { left: 13px; animation-duration: 458ms; }
  .bar:nth-child(5)  { left: 17px; animation-duration: 400ms; }
  .bar:nth-child(6)  { left: 21px; animation-duration: 427ms; }
  .bar:nth-child(7)  { left: 25px; animation-duration: 441ms; }
  .bar:nth-child(8)  { left: 29px; animation-duration: 419ms; }

  
  @keyframes sound {
    0% {
        opacity: .35;
        height: 3px; 
    }
    100% {
        opacity: 1;       
        height: 28px;        
    }
  }