@keyframes blinking {
    0%, 49% {
      background-color: #4a83a8;
    }
    50%, 100% {
      background-color: #396480;
    }
  }

#idleCountdown {
    border-radius:0 0 0 5px;
    position:fixed;
    right:0px;
    top:0px;
    padding: 0;
    font-size: .6em;
    max-height:0;
    min-width:38px;
    text-align:center;
    visibility: collapse;
    z-index: 1000000;
}

#idleCountdown.active {
    padding: 2px 5px;
    background: #4a83a8;
    color: #fff;
    max-height:18px;
    visibility: visible;
    height:18px;
    animation: blinking 3s infinite; 
    
}