Css login

<style>

       *{ 
           font-size: 14px; 
           font-family: sans-serif; 
       } 
       form.registro{ 
           background: none repeat scroll 0 0 #F1F1F1; 
           border: 1px solid #DDDDDD; 
           margin: 0 auto; 
           padding: 20px; 
           width: 278px; 
           box-shadow:0px 0px 20px black;  
           border-radius:10px;  
           position:relative; 
           top:30px; 
       } 
       form.registro div { 
           margin-bottom: 15px; 
           overflow: hidden; 
       } 
       form.registro div label { 
           display: block; 
           float: left; 
           line-height: 25px; 
       } 
       form.registro div input[type="text"], form.registro div input[type="password"] {
           border: 1px solid #DCDCDC; 
           float: right; 
           padding: 4px; 
       } 
       form.registro div input[type="submit"] { 
           background: none repeat scroll 0 0 #DEDEDE; 
           border: 1px solid #C6C6C6; 
           float: right; 
           font-weight: bold; 
           padding: 4px 20px; 
       } 
       .error{ 
           color: red; 
           font-weight: bold; 
           margin: 10px; 
           text-align: center; 
       } 

</style>

<form action="" method="post" class="registro">

<label>Usuario:</label> <input type="text" name="usuario">

<label>Clave:</label> <input type="password" name="password">

<label>Repetir Clave:</label> <input type="password" name="repassword">

<input type="submit" name="enviar" value="Registrar">

<input type="submit" name="comprobar" value="Comprobar">

</form>