<!DOCTYPE html>
<html>
	<head>
		<meta charset="utf-8">
		<meta name="viewport" content="width=device-width">
		<title>Test</title>
		<style>
			canvas {
				border: 1px dashed blue;
			}
		</style>
	</head>
	<body>
		<canvas id="main" width="50" height="300"></canvas>

		<script src="script.js"></script>
	</body>
</html>