et level0 = 0, left0 = 0, width0 = 0;
	let nav = [], navIndex, matchval;
	let inverted = false;
	const levels = Array(85);
	for (let h = 0; h < levels.length; h++) {
		levels[h] = [];
	}

	const canvas = document.getElementById('canvas');
	const c = canvas.getContext('2d');
	const hl = document.getElementById('hl');
	const status = document.getElementById('status');

	const canvasWidth = canvas.offsetWidth;
	const canvasHeight = canvas.offsetHeight;
	canvas.style.width = canvasWidth + 'px';
	canvas.width = 