<!-- BEGIN COPY / PASTE -->
        <style>
            .custom-valid-feedback {
                color: #28a745; /* Custom green color */
                font-weight: bold;
            }

            .custom-invalid-feedback {
                color: #dc3545; /* Custom red color */
                font-weight: bold;
            }
        </style>

        <form class="needs-validation" novalidate>
            <div class="mb-3">
                <label for="validationCustom01" class="form-label">First name</label>
                <input type="text" class="form-control" id="validationCustom01" required>
                <div class="custom-valid-feedback">
                    Looks good!
                </div>
                <div class="custom-invalid-feedback">
                    Please provide a valid first name.
                </div>
            </div>
            <button class="btn btn-primary" type="submit">Submit form</button>
        </form>
        <!-- END COPY / PASTE -->