Submition Form

#parent {
    display: list-item;
    align-items: stretch;
}

#form {
    display: list-item;
    align-items: center;
}

#small-div {
    text-align: center;
    width: 100%;
    height: 100%;

}

body {
    width: 100%;
    height: 100%;
}

<!DOCTYPE html>
<html>
<title>Submition Form</title>
<body>

<div id="parent">

    <div id="small-div">
        <p>sign up
        <p>Sign up to learn the most important skill of 21st century</p>
        </p>

        <form class="form">
            <input type="text" name="firstname" placeholder="YOUR NAME">
            <br>
            <input type="number" name="phonenumber" placeholder="PHONE NUMBER">
            <br>
            <input type="email" name="email" placeholder="EMAIL">
            <br>
            <input type="text" name="address" placeholder="ADRRESS">
            <br>
            <input type="text" name="college" placeholder="COLLEGE/SCHOOL/UNIVERSITY">
            <br>
            <input type="radio" name="courses" value="btech">
            <label for="btech">B.tech| </label>
            <input type="radio" name="courses" value="mtech">
            <label for="mtech">M.tech| </label>
            <input type="radio" name="courses" value="bca">
            <label for="bca">B.C.A| </label>
            <input type="radio" name="courses" value="mca">
            <label for="mca">M.C.A| </label>
            <input type="radio" name="courses" value="other">
            <label for="other">Other| </label>
            <br>
            <input type="radio" name="Discipline" value="CS">
            <label for="CS">CS| </label>
            <input type="radio" name="Discipline" value="IT">
            <label for="IT">IT| </label>
            <input type="radio" name="Discipline" value="SE">
            <label for="SE">SE| </label>
            <input type="radio" name="Discipline" value="EE">
            <label for="EE">EE| </label>
            <input type="radio" name="Discipline" value="ECE">
            <label for="ECE">ECE| </label>
            <input type="radio" name="Discipline" value="EEE">
            <label for="EEE">EEE| </label>
            <input type="radio" name="Discipline" value="Other">
            <label for="Other">Other| </label>


        </form>

    </div>
</div>


</body>
</html>