Conteneur de formulaire

HTML

<div class="container overflow-hidden">
    <div class="row">
        <div class="col-sm-12 col-md-4 margin-top-block-xl">
            <aside class="gnb-progress-steps-nav">
                <h2>Comment postuler</h2>
                <ul class="gnb-progress-steps-circle">
                    <li class="complete">
                        <div><a href="#">1. Lire et accepter les termes</a></div>
                    </li>
                    <li class="current">
                        <div>2. Coordonnées</div>
                    </li>
                    <li>
                        <div>3. Demande de subvention</div>
                    </li>
                    <li>
                        <div>4. Examiner et soumettre</div>
                    </li>
                </ul>
            </aside>
        </div>
        <div class="col margin-top-block-xl">
            <article class="form-column margin-top-0 ">
                <form class="gnb-form-container-gray">
                    <h2>Coordonnées</h2>
                    <p>Entrez vos coordonnées et sélectionnez votre langue préférée.</p>
                    <div class="row row-cols-1 margin-bottom-md">
                        <div class="col">
                            <label for="firstname">Prénom<span class="required">*</span><span
                                    class="sr-only">obligatoire</span></label>
                            <input type="text" required name="firstname" id="firstname" />
                        </div>
                        <div class="col">
                            <label for="lastname">Nom de famille<span class="required">*</span><span
                                    class="sr-only">obligatoire</span></label>
                            <input type="text" required name="lastname" id="lastname" />
                        </div>
                        <div class="col">
                            <label for="email">Adresse e-mail<span class="required">*</span><span
                                    class="sr-only">obligatoire</span></label>
                            <input type="email" required name="email" id="email" />
                        </div>
                        <div class="col">
                            <label for="emailconfirmation">Confirmer l'adresse e-mail<span
                                    class="required">*</span><span
                                    class="sr-only">obligatoire</span></label>
                            <input type="email" required name="email" id="emailconfirmation" />
                        </div>
                        <div class="col">
                            <label for="phone">Numéro de téléphone</label>
                            <input type="text" style="max-width: 10em;" id="phone" />
                        </div>
                    </div>
                    <h3>Langue préférée</h3>

                    <fieldset class="gnb-radio-buttons-expanded">
                        <legend>Choisissez votre langue préférée pour la communication concernant votre
                            demande.<span class="required">*</span><span
                                class="sr-only">obligatoire</span></legend>
                        <div class="set">
                            <div class="row">
                                <div class="col-sm-6"><label for="english"><input id="english"
                                            type="radio" name="languagepreference" required
                                            value="English"><span
                                            class="label-title">English</span></label>
											</div>
                                <div class="col-sm-6"><label for="francais"><input id="francais"
                                            type="radio" name="languagepreference" required
                                            value="Français"><span
                                            class="label-title">Français</span></label>
                                </div>
                            </div>
                        </div>
                    </fieldset>
                    <hr />
                    <button class="gnb-button">Suivant</button> 
					<button type="button" class="gnb-btn-secondary">Retour en arrière</button>
                </form>
            </article>
        </div>
    </div>
</div>