html, body {
    height: 100%;
    margin: 0;
  }

  body {
    background: black;
    display: flex;
    align-items: center;
    justify-content: center;
  }
  canvas {
    border: 5px solid white;
  }
    #scor  {
    position: fixed;
    bottom: 0;
    text-align:center;
}

      #start
      {
          position:fixed;
          width: 400px;
          height: 400px;
          margin: auto;
          background-image: url("butonstart.png");
      }
.alert {
  padding: 10px;
  background-color: #2196F3;
  color: white;
  margin-bottom: 15px;
    text-align: center;
    width:100%;
}
#closebtn {
  margin-left: 15px;
  color: white;
  font-weight: bold;
  float: right;
  font-size: 22px;
  line-height: 20px;
    cursor: pointer;
}