HTML5でログインフォームの書き方
HTML
<section class="loginform cf">
<form name="login" action="/path" method="POST" accept-charset="utf-8">
<ul>
<li><label for="usermail">Login Name</label>
<input type="text" name="loginName" placeholder="login name" required></li>
<li><label for="password">Password</label>
<input type="password" name="password" placeholder="password" required></li>
<li><input type="submit" value="Login"></li>
</ul>
</form>
</section>
CSSは参考リンク参照
参考
http://www.hongkiat.com/blog/html5-loginpage/