body{overflow:hidden;}
.login{ height:260px;width:260px;padding: 20px;background-color:rgba(0,0,0,0.5);border-radius: 4px;position:absolute;left: 50%;top: 50%; margin:-150px 0 0 -150px;z-index:99;}
.login h1{ text-align:center; color:#fff; font-size:24px; margin-bottom:20px; }
.form_code{ position:relative; }
.form_code .code{ position:absolute; right:0; top:1px; cursor:pointer; }
.login_btn{ width:100%; }