@media (max-width: 768px) {

    header {
        display: none;
    }

    .mobile-navbar {
        position: fixed;
        top: 0;
        left: 0;
        z-index: 999;
        width: 100%;
        height: 100%;
        background-color: rgba(0, 0, 0, 0.8);
        display: block;
    }

    .mobile-navbar.open {
        display: flex;
        align-items: center;
        justify-content: center;
    }

    .mobile-navbar-toggle {
        color: #000;
        font-size: 24px;
        cursor: pointer;
        margin-bottom: 10px;
    }

    .burger-line {
        width: 25px;
        height: 3px;
        background-color: #000;
        margin-bottom: 5px;
    }

    .mobile-navbar-menu {
        list-style: none;
        padding: 0;
        margin: 0;

    }

    .mobile-navbar-menu.open {
        display: block;
    }

    .mobile-navbar-menu li {
        margin-bottom: 10px;
    }

    .mobile-navbar-menu li a {
        color: #000;
        text-decoration: none;
        transition: color 0.3s;
    }

    .mobile-navbar-menu li a:hover {
        color: #aaa;
    }

    .part-one-section {
        flex-direction: column;
        margin-top: 48px;
        text-align: center;
    }

    .cercle {
        width: 200px;
        height: 200px;
        margin: 0;
        display: flex;
        justify-content: flex-start;
        margin: auto;
        margin-top: 30px;
    }

    .part-one-text-section {
        display: flex;
        justify-content: center;
        flex-direction: column;
        align-items: center;
        margin-left: 0;
    }

    .title-part-one {
        font-size: 38px;
        margin-left: 8px;
        margin-bottom: 20px;
    }

    .text-part-one {
        width: auto;
        text-align: center;
        margin-left: 16px;
        margin-right: 16px;
        font-size: 28px;
    }

    .part-left {
        margin: auto;
    }

    .part-right {
        margin: auto;
    }

    .title-section-left {
        font-size: 40px;
        display: flex;
        justify-content: center;
        margin-bottom: 20px;
        text-align: center;
        margin-top: 93.200px;
    }

    .text-section-left {
        margin-left: 16px;
        margin-right: 16px;
        font-size: 22px;
        margin-bottom: 16px;
        margin-top: 26px;
        text-align: center;
    }

    .line-separation {
        margin-top: 26px;
    }

    .line-separation-cv {
        margin-top: 26px;
        margin-bottom: 0;
    }

    .title-section-right {
        width: auto;
        margin: auto;
        justify-content: center;
        margin-top: 16px;
        margin-bottom: 16px;
        margin-right: 16px;
        margin-left: 16px;
        margin-top: 26px;
        font-size: 40px;
        margin-top: 93.200px;
        text-align: center;
    }

    .text-section-right {
        font-size: 22px;
        margin-left: 16px;
        margin-right: 16px;
        text-align: center;
    }

    .strong-txt {
        text-align: center;
    }

    .li-txt {
        font-size: 22px;
        text-align: center;
    }

    .li-txt-last {
        font-size: 22px;
        margin-bottom: 0;
        margin-right: 8px;
        text-align: center;
    }

    .part-Forms {
        margin: 0;
        padding: 32px;
        width: auto;
        justify-content: center;
    }

    .title-section-center {
        margin-top: 26px;
    }

    .text-section-center {
        font-size: 22px;
        padding-right: 16px;
        padding-left: 16px;
    }

    .form-row {
        gap: 0;
        flex-direction: column;
    }



    .background-section-img {
        margin-left: 0;
        margin-right: 0;
    }

    .footer-line-row {
        flex-direction: column;
        text-align: center;
    }

    .txt-footer-line {
        font-size: 16px;
        margin: 0;
    }

    .footer-line-row-phrase {
        flex-direction: column;
        text-align: center;
        justify-content: center;
    }

    .img-illu-footer-phrase {
        margin: 0;
    }

    .footer-line-white {
        width: auto;
    }

    .txt-footer-line-phrase {
        font-size: 16px;
    }

    .contact-forms-device {
        display: flex;
        flex-direction: column;
        align-content: center;
        justify-content: center;
        align-items: center;
        margin-left: 0;
        margin-right: 0;
    }

    .object {
        width: 100%;
    }

    .submit {
        width: 100%;
    }

    #object {
        width: 100%;
    }

    #message {
        width: 100%;
    }

    .submit {
        justify-content: center;
        display: flex;
    }

    .obj {
        width: 100%;
    }

    .msg {
        width: 100%;
    }

    .part-Forms {
        padding: 0;
    }

    h2.title-section-left {
        margin-top: 0;
    }

    .menu-burger {
        display: block;
    }

    /* vidéo */

    .container-video {
        flex-direction: column;
    }

    .sidebar {
        width: 100%;
        margin-top: 16px;
    }

    .video-list {
        flex-direction: column;
        overflow-x: hidden;
        overflow-y: hidden;
        white-space: nowrap;
        width: auto;
        margin: auto;
        margin-left: 16px;
        margin-right: 16px;
    }

    .video {
        margin-right: 0;
        border-bottom: none;
        border-right: 1px solid #ccc;
    }

    .video:last-child {
        margin-right: 0;
        border-right: none;
    }

    .video-thumbnail {
        width: 80px;
        height: 100%;
        object-fit: cover;
    }

    .video-title {
        width: 80px;
        
    }

    .main-video {
        display: flex;
        justify-content: center;
        width: 100%;
margin: auto;
    }

    .img-logo-qvt{
        width: 340px;
        display: flex;
        align-items: center;
        justify-content: center;
        margin: auto;
        margin-bottom: 100px;
    }

    .qvt-logo{
        margin-top: 0;
    }
    
}