1 <!DOCTYPE html> 2 <html> 3 <head lang="en"> 4 <meta charset="UTF-8"> 5 <title></title> 6 <style type="text/css"> 7 8 div{ 9 border-style: solid; 10 border-color: blueviolet; 11 border-width: 2px; 12 height: 200px; 13 14 //塌缩collapse 15 } 16 </style> 17 </head> 18 <body> 19 20 <div></div> 21 </body> 22 </html>