<!--
  模板: 极地区域图 (polar area)
  引擎: Chart.js
  数据形态: S3 极简 / S6 构成占比（3-6 子类）
  DOM ID: chart-polar-area
  说明: 扇形角度均等、半径编码数值，适合展示 3-6 个子类相对最大值
  前置: HTML 需内联 chart.js.min.js
-->
(function() {
  const dom = document.getElementById('chart-polar-area');
  const ctx = dom.getContext('2d');
  new Chart(ctx, {
    type: 'polarArea',
    data: {
      labels: ['类别A', '类别B', '类别C', '类别D', '类别E'],
      datasets: [{
        data: [78, 65, 92, 45, 60],
        backgroundColor: [
          'rgba(59,130,246,0.6)', 'rgba(34,197,94,0.6)',
          'rgba(245,158,11,0.6)', 'rgba(239,68,68,0.6)',
          'rgba(168,85,247,0.6)'
        ],
        borderColor: [
          'rgba(59,130,246,1)', 'rgba(34,197,94,1)',
          'rgba(245,158,11,1)', 'rgba(239,68,68,1)',
          'rgba(168,85,247,1)'
        ],
        borderWidth: 2
      }]
    },
    options: {
      responsive: true,
      maintainAspectRatio: false,
      plugins: {
        legend: { position: 'bottom' },
        tooltip: { callbacks: { label: ctx => ctx.label + ': ' + ctx.raw } }
      },
      scales: {
        r: { beginAtZero: true, max: 100, ticks: { stepSize: 20 } }
      }
    }
  });
})();