JSFiddle - React, Tailwind, and code Playground
by Roman
HTML
<canvas id="tutorial" width="1920" height="1980" style="width:100%; height:100%"></canvas>
CSS
canvas { background: #c0c9c9;}
JavaScript
var canvas = document.getElementById('tutorial');
if (canvas.getContext) {
var ctx = canvas.getContext('2d');
var widthCanvas = 960;
var heightCanvas = 1910;
var widthWhiteLine = 250;
var startY = 0;
//shadow
ctx.shadowColor = '#111';
ctx.shadowBlur = 20;
//right top stroke
ctx.beginPath();
ctx.lineWidth = widthWhiteLine;
ctx.shadowColor = '#111';
ctx.shadowBlur = 20;
ctx.strokeStyle = '#f2f2f2';
ctx.moveTo( 1920 + widthWhiteLine /1.5 , 0);
ctx.lineTo(widthCanvas - widthWhiteLine /1.6, widthCanvas + widthWhiteLine *1.4);
ctx.stroke();
//left top stroke
ctx.beginPath();
ctx.lineWidth = widthWhiteLine;
ctx.strokeStyle = '#f2f2f2';
ctx.moveTo(-widthWhiteLine /1.4 , startY);
ctx.lineTo(widthCanvas + widthWhiteLine / 1.6, widthCanvas + widthWhiteLine *1.4);
ctx.stroke();
//left bottom stroke
ctx.beginPath();
ctx.lineWidth = widthWhiteLine;
ctx.strokeStyle = '#f2f2f2';
ctx.moveTo(-widthWhiteLine /1.4, heightCanvas);
ctx.lineTo(widthCanvas + widthWhiteLine / 1.6, widthCanvas - widthWhiteLine *1.4);
ctx.stroke();
ctx.closePath;
//right...