CSS3 Styled Login Form

HTML

<!DOCTYPE html>
<html>
    <head>
        <link href="/Content/login.css" rel="stylesheet" />
        <title>login</title>
    </head>
    <body>
        <form>
            <input type="email" placeholder="email address">
            <input type="submit" value="Sign In">
        </form>
    </body>
</html>

CSS

body {
    background-color: #858585;
}

form {
    padding: 40px;
    background-color: white;
    margin: auto;
    margin-top: 100px;
    width: 400px;
    font-size: 18px;

    border-radius: 10px;
    box-shadow:  0px 0px 8px 5px rgba(0, 0, 0, .4);
    min-height: 100px;

}

input[type=email],
input[type=submit] {
    display: block;
    font-size: 18px;
    margin-bottom: 15px;
}

input[type=email] {
    width: 400px;
    padding: 4px;
    float: right;
}

input[type=submit] {
    padding: 8px;
    width: 100px;
    float: right;
    color:green;
    background: transparent;
    
    
    
    
}