fixed定位
<!DOCTYPE html> <html lang="en"> <head> <meta charset="UTF-8"> <title>fixed</title> <style type="text/css"> .div1{ position: fixed; left: 100%; top: 50%; margin-left: -200px;/*向左移动一个DIV的宽度就可以显示了的*/ margin-top: -100px; width: 200px; height: 200px; border: 1px solid blue; background: pink; z-index: 999; } .div2{ margin: 0 auto; width: 500px; height: 1000px; border: 1px solid blue; background: silver; } </style> </head> <body> <div class="div1"> 11111111111111111111 </div> <div class="div2"></div> </body> </html>
原文：http://www.cnblogs.com/qianjilou/p/6368817.html