.chart-wrapper {
 width: 95vh;
 margin: auto;
} 

const ctx = document.getElementById('myChart') as HTMLCanvasElement

//この2つの値を設定するだけ!!
const percentage = 76 //グラフのパーセンテージ(76%)
const backgroundColor = 'rgba(255, 0, 0, 1)' //グラフの色(赤)

new Chart(ctx, {
  type: 'doughnut',
  data: {
    datasets: [{
      data: [percentage, 100 - percentage],
      backgroundColor: [
        backgroundColor, //赤色
        'rgba(0, 0, 0, 0)',
      ],
      borderWidth: 0
    }]
  }
})