.contacter{
    /*! display none!!!!! */
    display: none;

    position: fixed;
    right: 20px;
    bottom: 20px;

    padding: 10px 20px;
    border: none;
    border-radius: 16px;
    background-color: var(--black);
    z-index: 999;

    font-size: 18px;
    color: var(--white);
    text-decoration: none;
}
.contacter:hover{
    text-decoration: none;
    color: var(--white);
}