@-moz-keyframes rotation {
    100% { -moz-transform: rotate(-360deg);
    }
}
@-webkit-keyframes rotation {
    100% { -webkit-transform: rotate(-360deg);
    }
}
@keyframes rotation {
    100% { -webkit-transform: rotate(-360deg); transform:rotate(-360deg);
    }
}

@keyframes cloud {
    0%{
        transform: translateX(-60%);
    }
    100%{
        transform: translateX(40%);
    }

}

html {
    margin: 0 auto;
    box-sizing: border-box;
    font-size: 62.5%;
}
*,
*:before,
*:after {
    box-sizing: inherit;
}

.flex{
    display: flex;
}
main{
    flex-grow:1;
    justify-content: center;
    align-items: center;
    overflow: hidden;
    position: relative;
}
body{
    /*background-image: url(/picture/fond_acceuil.jpg);*/
    /*background-repeat: no-repeat;*/
    /*background-size: cover;*/
    background: url(/picture/fond_acceuil.jpg) no-repeat center fixed;
    -webkit-background-size: cover; /* pour anciens Chrome et Safari */
    background-size: cover; /* version standardisée */
    /*font-family: 'David Libre', serif;*/
    font-family: 'Cantarell', sans-serif;
    min-height: 100vh;
    flex-direction: column;
}
main h1 {
    text-align: center;
    font-size: 5rem;
    text-shadow: 1rem 1rem 2rem white, 0 0 1rem white, 0 0 0.2rem white;
    display: none;
}
main article{
    position: relative;
    flex-direction: column;
    justify-content: center;
    align-items: center;
}
main article>p{
    text-align: center;
    font-size: 3rem;
    margin: 2%;
    padding: 0 5% ;
    text-shadow: 1rem 1rem 2rem white, 0 0 1rem white, 0 0 0.2rem white;
    z-index: 1;
}
main section>article>img{
    max-width: 20%;
    display: none;
    -webkit-animation:rotation 8s linear infinite;
    -moz-animation:rotation 8s linear infinite;
    animation:rotation 8s linear infinite;
}
.cloud1{
    position: absolute;
    top:-300px;
    animation: cloud 20s linear infinite;
    -webkit-animation:cloud 20s linear infinite;
    -moz-animation:cloud 20s linear infinite;
}

@media screen and (max-width: 640px) {

    main section > article > img{
        order: 1;
        max-width: 75%;
    }
    main article>p{
        order: 2;
    }
    main article> h1{
        margin: 50px 5%;
        font-size: 4rem;
    }

}