Код на jsfiddle.first-form {
display:block;
width:200px;
margin:100px auto;
padding:10px;
background-color:white;
border:3px solid #fff;
border-radius:10px;
}
.first-form input{
margin: 10px;
height: 22px;
border:1px solid #249FEB;
border-radius:5px;
box-shadow: 0 0 10px rgba(35,155,230,0.7);
padding-left:10px;
color:#999;
}
.first-form button{
display:block;
width:120px;
margin:10px auto;
background-color:#239AE3;
border:1px solid #249FEB;
border-radius:5px;
color:white;
}
<div class='first-form' >
<form id='input_form' action='register' name='input_name_form' method='post'>
<input name='name_input' type='text' placeholder='login'><br/>
<input name='mail_input' type='text' placeholder='mail'><br/>
<input name='pass_input' type='password' placeholder='password'><br/>
<button>
Sign up for Titanium
</button>
</form>