      animation: progressanim 2s linear infinite;
    }

    @keyframes progressanim {
      0% {
        background-position: 50px 50px;
      }
      100% {
        background-position: 0 0;
      }
    }
  </style>
  </head>
  <body>
    <canvas id="c" tabindex="1"></canvas>
    <div id="ui">
      <div id="left"><img src="resources/images/left.svg"></div>
      <div style="flex: 0 0 40px;"></div>
      <div id="right"><img src="resources/images/right.svg"></div>
    </div>
    <div id="loading">
      <