wrapping the container to have div card

Question

Hi Team

I have created a container to have div card, but somehow when i select either of the payment options i dont see it and yet have tried to create a css for it. what am i missing from my current code

// html code

<!---Debit card information details form----->
				<div class="card-container">
    <div class="container">
        <div class="creditCardForm" style="display:none;">
            <div class="heading">
                <h1>Confirm Purchase</h1>
            </div>
            <div class="payment">
                <form>
                    <div class="form-group owner">
                        <label for="owner">Owner</label>
                        <input type="text" class="form-control" id="owner">
                    </div>
                    <div class="form-group CVV">
                        <label for="cvv">CVV</label>
                        <input type="text" class="form-control" id="cvv">
                    </div>
                    <div class="form-group" id="card-number-field">
                        <label for="cardNumber">Card Number</label>
                        <input type="text" class="form-control" id="cardNumber">
                    </div>
                    <div class="form-group" id="expiration-date">
                        <label>Expiration Date</label>
                        <select>
                            <option value="01">January</option>
                            <option value="02">February</option>
                            <option value="03">March</option>
                            <option value="04">April</option>
                            <option value="05">May</option>
                            <option value="06">June</option>
                            <option value="07">July</option>
                            <option value="08">August</option>
                            <option value="09">September</option>
                            <option value="10">October</option>
                            <option value="11">November</option>
                            <option value="12">December</option>
                        </select>
                        <select>
                            <option value="16"> 2016</option>
                            <option value="17"> 2017</option>
                            <option value="18"> 2018</option>
                            <option value="19"> 2019</option>
                            <option value="20"> 2020</option>
                            <option value="21"> 2021</option>
                        </select>
                    </div>
                    <div class="form-group" id="credit_cards">
                        <img src="img/visa.jpg" id="visa">
                        <img src="img/mastercard.jpg" id="mastercard">
                        <img src="img/amex.jpg" id="amex">
                    </div>
                    <div class="form-group" id="pay-now">
                        <button type="submit" class="btn btn-primary" id="confirm-purchase">Confirm</button>
                    </div>
                </form>
            </div>
        </div>
    </div>
</div>

// css code
.card-container {
       display: flex;
       justify-content: center;
       align-items: center;
       height: 100vh;
   }