html5手机登录表单，手机注册表单，弹出表单，手机弹出。

HTML结构

<div class="demo"> 
<nav class="main_nav"> 
<ul> 
<li><a class="cd-signin" href="#0">登录</a></li> 
<li><a class="cd-signup" href="#0">注册</a></li> 
</ul> 
</nav> 
</div> 
 
<div class="cd-user-modal"> 
<div class="cd-user-modal-container"> 
<ul class="cd-switcher"> 
<li><a href="#0">用户登录</a></li> 
<li><a href="#0">注册新用户</a></li> 
</ul> 
<div id="cd-login"> <!-- 登录表单 -->
<form class="cd-form"> 
<p class="fieldset"> 
<label class="image-replace cd-username" for="signin-username">用户名</label> 
<input class="full-width has-padding has-border" id="signin-username" type="text" placeholder="输入用户名"> 
</p> 
<p class="fieldset"> 
<label class="image-replace cd-password" for="signin-password">密码</label> 
<input class="full-width has-padding has-border" id="signin-password" type="text" placeholder="输入密码"> 
</p> 
<p class="fieldset"> 
<input type="checkbox" id="remember-me" checked> 
<label for="remember-me">记住登录状态</label> 
</p> 
<p class="fieldset"> 
<input class="full-width2" type="submit" value="登 录"> 
</p> 
</form> 
</div> 
<div id="cd-signup"> <!-- 注册表单 -->
<form class="cd-form"> 
<p class="fieldset"> 
<label class="image-replace cd-username" for="signup-username">用户名</label> 
<input class="full-width has-padding has-border" id="signup-username" type="text" placeholder="输入用户名"> 
</p> 
<p class="fieldset"> 
<label class="image-replace cd-email" for="signup-email">邮箱</label> 
<input class="full-width has-padding has-border" id="signup-email" type="email" placeholder="输入mail"> 
</p> 
<p class="fieldset"> 
<label class="image-replace cd-password" for="signup-password">密码</label> 
<input class="full-width has-padding has-border" id="signup-password" type="text" placeholder="输入密码"> 
</p> 
<p class="fieldset"> 
<input type="checkbox" id="accept-terms"> 
<label for="accept-terms">我已阅读并同意 <a href="#0">用户协议</a></label> 
</p> 
<p class="fieldset"> 
<input class="full-width2" type="submit" value="注册新用户"> 
</p> 
</form> 
</div> 
<a href="#0" class="cd-close-form">关闭</a> 
</div> 
</div>