非常酷的js图形渐隐导航菜单栏

body { background:#799AE1; margin:0px; font:normal 12px 宋体; } table { border:0px; } td { font:normal 12px 宋体; } img { vertical-align:bottom; border:0px; } a { font:normal 12px 宋体; color:#215DC6; text-decoration:none; } a:hover { color:#428EFF } .sec_menu { border-left:1px solid white; border-