block-negative-4-ref2.html (343B)
1 <!DOCTYPE html> 2 <html> 3 <head> 4 <style type="text/css"> 5 html, body { 6 margin: 0; padding: 5px; 7 } 8 #positive, #negative { 9 height: 20px; 10 background-color: blue; 11 } 12 #margin { 13 height: 10px; 14 } 15 #negative { 16 background-color: green; 17 } 18 </style> 19 </head> 20 <body> 21 <div id="positive"></div> 22 <div id="margin"></div> 23 <div id="negative"></div> 24 </body> 25 </html>