ex: 1;
        /* 样式尺寸 */
        width: 50%;
        height: 100%;
        background-color: #fefefe;
      }
    </style>
  </head>
  <body>
    <p>练习canvas动画和文字相关的API</p>
    <div class="wrap">
      <canvas id="bar"></canvas>
      <canvas id="circle"></canvas>
    </div>
  </body>
  <script>
    const MARGIN = 50
    const barWidth = 400
    const barHeight = 100
    const radius = 150
    const circleBg = '#eee'
    let barColor, textColor

    function randomColor() {
    