JSFiddle - React, Tailwind, and code Playground

HTML

<canvas id="canvas1" width="500" height="500"></canvas>

JavaScript

var can = document.getElementById('canvas1');
var c = can.getContext('2d');

    c.lineCap="round";
    c.fillStyle="#353535";
    c.translate(100,100);
    function slit(p){
        shade = 256*p;
        th = 2*Math.PI*p;
        cos = Math.cos(th);
        sin = Math.sin(th);
        c.strokeStyle = '#'+((shade<<16)+(shade<<8)+shade).toString(16);
        c.beginPath();
        c.moveTo(55*cos, 55*sin);
        c.lineTo(84*cos, 84*sin);
        c.stroke();
        c.closePath();
    }
    c.lineWidth=0;
    c.arc(0,0,100,0,Math.PI*2);
    c.fill();
    c.lineWidth=7;
    for(var i = 0;i<1;i+=0.05){slit(i);}