How can i center the form called form_login horizontally and vertically in my page ?
Here is the HTML I'm using right now:
<body>
    <form id="form_login">
        <p>
            <input type="text" id="username" placeholder="username" />
        </p>
        <p>
            <input type="password" id="password" placeholder="password" />
        </p>
        <p>
            <input type="text" id="server" placeholder="server" />
        </p>
        <p>
            <button id="submitbutton" type="button">Se connecter</button>
        </p>
    </form>
</body>
I have tried to do the following css but my form is never centered :
#form_login {
    left: 50%;
    top: 50%;
    margin-left: -25%;
    position: absolute;
    margin-top: -25%;
}
 
     
     
     
     
     
     
     
     
    