1<!doctype html> 2<html> 3<head> 4<style> 5body { 6 background-image: 7 linear-gradient(45deg, #000000 25%, transparent 25%), 8 linear-gradient(-45deg, #000000 25%, transparent 25%), 9 linear-gradient(45deg, transparent 75%, #000000 75%), 10 linear-gradient(-45deg, transparent 75%, #000000 75%); 11 12 background-size:80px 80px; 13 background-position: 0 0, 0 80px, 80px -80px, -80px 0px; 14} 15</style> 16</head> 17<body> 18</body> 19</html> 20