nav {
    display: flex;
    justify-content: center;
    padding: 20px;
    position: fixed;
    top : 0;
    left: 50%;
    transform: translateX(-50%);
    width : 100%;
    
}
.nav-1 {
    width : 150px;
    height : 50px;
    background-color: black;
    color: white;
    padding: 10px 15px;
    cursor: pointer;
    border-radius: 2px;
    transition: all 0.2s linear;
    margin-right: 10px;
}
.nav-1:hover {
    background-color: white;
    color: black;
    border: 1px black solid!important;
}
.visible {
    display: block!important;
}
.line {
    background-color : black;
    height : 2px;
    width : 60%;
    margin: 10px auto 20px auto;
    position: fixed;
    top : 50px;
    left: 50%;
    transform: translateX(-50%);
    

}