h1 {
    color:rgb(255, 255, 255);
    font-weight: bold;
}
body, html {
    background: #ffffff;
  }
  
  .container {
    position: absolute;
    left: 50%;
    top: 50%;
    transform: translate(-50%,-50%);
    margin: 0 auto 0;
  }
  
  .button--pulse {
    position: relative;
    display: block;
    border: 2.5px solid #000000;
    width: 10px;
    height: 10px; 
    border-radius: 50%;
    cursor: pointer;
    -webkit-animation: pulse 5.0s infinite cubic-bezier(0.25, 0.46, 0.45, 0.94);
    animation: pulse 5.0s infinite cubic-bezier(0.25, 0.46, 0.45, 0.94); 
  }
  
  .button--pulse::before {
    content: '';
    display: inline-block;
    width: 5px;
    height: 5px;
    border-radius: 50%;
    background: #CC3333;
    position: absolute;
    box-shadow: 0 0 0 0 rgba(186, 49, 39, 0.5);
    left: 50%;
    top: 50%;
    -ms-transform: translate(-50%,-50%); /* IE 9 */
    -webkit-transform: translate(-50%,-50%); /* Safari and Chrome */
    transform: translate(-50%,-50%);
    -webkit-animation: pulse-shadow 2.0s infinite cubic-bezier(0.25, 0.46, 0.45, 0.94);
    animation: pulse-shadow 2.0s infinite cubic-bezier(0.25, 0.46, 0.45, 0.94);
  }
  
  @keyframes pulse {
    0% { 
      transform: scale(.8); 
    }
    70% {
      transform: scale(1);
    }
      100% {
      transform: scale(.8);
    }
  }
  
  @keyframes pulse-shadow {
    0% {}
    70% {
      box-shadow: 0 0 0 15px rgba(186,49,39, 0);
    }
      100% {
      box-shadow: 0 0 0 0 rgba(20,0,20, 0);
    }
  }