.webp #mainHeader {
    background: linear-gradient(180deg, rgba(33, 71, 84, .9), rgba(33, 71, 84, .9)), url(images/martinique7_tab.a7f4c103.webp) 50%
}

.no-webp #mainHeader {
    background: linear-gradient(180deg, rgba(33, 71, 84, .9), rgba(33, 71, 84, .9)), url(https://www.keyliance.fr/build/images/martinique7_tab.738bdbb0.jpg) 50%
}

article h2:first-child {
    margin-top: 0
}

article h2 {
    margin-top: 32px
}

iframe {
    border: none;
    height: 400px;
    margin: 15px 0 20px;
    max-width: 800px;
    width: 100%
}

@media(min-width:1000px) {
    .webp #mainHeader {
        background: linear-gradient(180deg, rgba(33, 71, 84, .9), rgba(33, 71, 84, .9)), url(https://www.keyliance.fr/build/images/martinique7_desktop.c8b40e0c.webp) 50%
    }

    .no-webp #mainHeader {
        background: linear-gradient(180deg, rgba(33, 71, 84, .9), rgba(33, 71, 84, .9)), url(https://www.keyliance.fr/build/images/martinique7_desktop.0565bb6d.jpg) 50%
    }

    article h2 {
        margin-top: 40px
    }

    iframe {
        display: block;
        height: 420px;
        margin: 30px auto 45px;
        max-width: 950px
    }
}

@media(min-width:1200px) {
    article h2 {
        margin-top: 50px
    }
}