body {
    font-family: Arial black;
    margin: 0;
    padding: 0;
    background-color: lightseagreen;
}

.banner {
    background-color: lightseagreen;
    color: lightpink;
    text-align: center;
    padding: 50px 0;
}

.startbutton {
    height: 40px;
    align-items: center;
    margin-left: 43%;
    margin-right: 43%;
    width: 14%;
    font-size: 20px;
    background: rgba(lightpink, .1);
    color: lightpink;
    background-color: lightseagreen;
    box-shadow: 0px 0px 0px 5px rgba(white, 0.95);
    border: 3px solid white;
    transition: .3s all ease-in-out;
    border-radius: 40px;
    position: relative;
    top: -30px
}

.startbutton:hover {
    background: rgba(black, 0.2);
    box-shadow: 0px 0px 10px 5px rgba(255, 255, 255, 255)
}

.topp {
    background-color: black;
    background-size: 100%;
    color: #ccc;
    width: 800px;
    height: 100px;
    border-radius: 20px;
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin: auto;
    margin-top: 1%;
}

#buttonleft {
    border-radius: 50%;
    color: lightpink;
    background-color: lightseagreen;
    margin-left: 2%;
    width: 40px;
    height: 40px;
}

#buttonleft:hover {
    background-color: rgb(255, 127, 236);
}

#buttonright {
    border-radius: 50%;
    color: lightpink;
    background-color: lightseagreen;
    margin-right: 2%;
    width: 40px;
    height: 40px;
}

#buttonright:hover {
    background-color: rgb(255, 127, 236);
}

#titletop {
    color: lightpink;
}

#yt {
    display: flex;
    align-content: center;
    justify-content: center;
}

#conteneur {
    display: flexbox;
    background-color: lightseagreen;
    color: lightpink;
    position: relative;
    top: -40px;
    height: 800px;
}

#reponse {
    display: vertical;
    margin: 0% 0% 0%;
}

.button:hover {
    background-color: lightseagreen;
}

.buttontest {
    display: none;
    height: 40px;
    font-size: 20px;
    align-items: center;
    margin-left: 43%;
    margin-right: 43%;
    width: 14%;
    background: rgba(lightpink, .1);
    color: lightpink;
    background-color: lightseagreen;
    box-shadow: 0px 0px 0px 5px rgba(white, 0.95);
    border: 3px solid white;
    transition: .3s all ease-in-out;
    border-radius: 40px;
    position: relative;
    top: 30px
}

.buttontest:hover {
    background: rgba(black, 0.2);
    box-shadow: 0px 0px 10px 5px rgba(255, 255, 255, 255)
}