#silenceBox {
      display: none;
      position: fixed;
      top: 0;
      left: 0;
      width: 100vw;
      height: 100vh;
      background-color: black;
      color: white;
      font-family: Arial, sans-serif;
      text-align: center;
      z-index: 9999;
    }
    #silenceBox div {
      font-size: 6vw;
      margin: 10px;
    }
    #countdown {
      font-weight: bold;
      font-size: 10vw;
    }