canvas(width="870", height="800")

canvas {
  // outline: 1px dashed crimson;
  transform: scale(0.5);
  transform-origin: 0 0;
}

function draw() {
  const canvas = document.querySelector("canvas");

  if (canvas.getContext) {
    var ctx = canvas.getContext("2d");

    ctx.beginPath();

    ctx.moveTo(800, 100);
    ctx.bezierCurveTo(860, 270, 850, 600, 650, 750);
    ctx.bezierCurveTo(500, 850, 50, 750, 20, 500);
    ctx.bezierCurveTo(0, 200, 750, -80, 800, 100);

    ctx.fillStyle = "crimson";
    ctx.fill();
  }
}

draw();