body {
    background: linear-gradient(90deg, gray, black, #383838, #202020, #282828, black);
    height: 140vh;
}

.credit {
    background: transparent;
    color: white;
    width: 200px;

    position: fixed;
    top: 90%;
    left: 93%;
    transform: translate(-50%, -50%);

    text-align: center;
    font-size: 15px;
}

.logo {
    width: 10vh;
    position: fixed;
    top: 0%;
    left: 0%;

    user-select: none;
}

.More_info_outsond {
    width: 850px;
    height: 400px;
    background: rgba(255, 255, 255, 0.07);
    color: white;
    border-radius: 15px;

    position: absolute;
    top: 40%;
    left: 50%;
    transform: translate(-50%, -50%);

    font-size: 14px;
    text-align: center;
}

    .More_info_outsond span {
        width: 780px;

        position: fixed;
        top: 50%;
        left: 50%;
        transform: translate(-50%, -50%);

        font-size: 18px;
    }

#retour_btn {
    width: 65px;
    height: 25px;
    background: red;
    color: white;
    border-radius: 20px;

    position: absolute;
    top: 6%;
    left: 5%;
    transform: translate(-50%, -50%);

    z-index: 9999;
    user-select: none;
    text-align: center;
    cursor: pointer;
}

.tuto_vidéo_outsond {
    width: 800px;
    height: 500px;
    background: rgba(0, 0, 0, 0.4);
    color: white;
    border-radius: 10vh;

    position: absolute;
    top: 50%;
    left: 50%;
    transform: translate(-50%, 40%);

    z-index: 9999;
}

.tuto_vidéo_outsond h1 {
    position: absolute;
    top: 3%;
    left: 10%;
    transform: translateX(-50%, -50%);

    text-align: center;
}

.tuto_vidéo_outsond video {
    width: 550px;
    height: 350px;
    max-height: 350px;
    border-radius: 15px;

    position: absolute;
    top: 60%;
    left: 50%;
    transform: translate(-50%, -50%);

    z-index: 9999;
}