html,
body {
    display: block;
    width: 100%;
    height: 100%;
    padding: 0;
    background: #000;
}

main section {
    display: block;
    width: 100%;
    min-height: 100vh;
}

h1 {
    color: white;
    margin-left: 20px;
    margin-top: 20px;
    font-family: 'Comfortaa', cursive;
    font-size: 3em;
}

main section:nth-child(1) {
    background: url("https://images.unsplash.com/photo-1459802071246-377c0346da93?ixlib=rb-0.3.5&q=85&fm=jpg&crop=entropy&cs=srgb&ixid=eyJhcHBfaWQiOjE0NTg5fQ&s=ab2d16da7bc6a2f19e43c7699aa9b391");
}

main section:nth-child(2) {
    background: url("https://images.unsplash.com/photo-1493130952181-47e36589f64d?ixlib=rb-0.3.5&q=85&fm=jpg&crop=entropy&cs=srgb&ixid=eyJhcHBfaWQiOjE0NTg5fQ&s=1a14e7273680d4598d928c39ee058618");
}

main section:nth-child(3) {
    background: url("https://images.unsplash.com/reserve/wPCyys8TPCHY3GXm2N2D_ssp_inthewoods_1.jpg?ixlib=rb-0.3.5&q=85&fm=jpg&crop=entropy&cs=srgb&ixid=eyJhcHBfaWQiOjE0NTg5fQ&s=654d988a19f43ca9ac27f2eacbe2a554");
}

#image {
    display: block;
    position: fixed;
    width: 50%;
    height: 60%;
    top: 25vh;
    left: 25.5vw;
    z-index: 9999;
    background: url(../animal.png);
    background-size: cover;
}

#image2 {
    opacity: 0.5;
    display: block;
    position: fixed;
    width: 50%;
    height: 60%;
    top: 25vh;
    left: 25.5vw;
    z-index: 9999;
    background: url(../animal_copie.png);
    background-size: cover;
}


@media screen and (min-width:768px) and (max-width:992px) {
    #image {
        width: 100%;
        height: 90%;
        left: 25vw;
    }

    #image2 {
        width: 100%;
        height: 90%;
        left: 25vw;
    }
}

@media screen and (min-width:576px) and (max-width:768px) {
    #image {
        width: 100%;
        height: 90%;
        left: 15vw;
    }

    #image2 {
        width: 100%;
        height: 90%;
        left: 15vw;
    }
}

@media screen and (min-width:200px) and (max-width:576px) {
    #image {
        width: 100%;
        height: 70%;
        left: 0vw;
    }

    #image2 {
        width: 100%;
        height: 70%;
        left: 0vw;
    }
}