51help TIY
码：
<!DOCTYPE html> <html> <head> <style> button { position:absolute; } button#b1 { top:20%;left:25%; nav-index:1; nav-right:#b2; nav-left:#b4; nav-down:#b2; nav-up:#b4; } button#b2 { top:40%;left:50%; nav-index:2; nav-right:#b3; nav-left:#b1; nav-down:#b3; nav-up:#b1; } button#b3 { top:70%;left:25%; nav-index:3; nav-right:#b4; nav-left:#b2; nav-down:#b4; nav-up:#b2; } button#b4 { top:40%;left:0%; nav-index:4; nav-right:#b1; nav-left:#b3; nav-down:#b1; nav-up:#b3; } </style> </head> <body> <button id="b1">Button 1</button> <button id="b2">Button 2</button> <button id="b3">Button 3</button> <button id="b4">Button 4</button> <p><b>注释：</b>目前只有 Opera 支持 nav-* 同时按下 Shift 键。</p> </body> </html>
查看结果: