.bg-img {
    background: linear-gradient(to left, rgba(0, 0, 0, 0.55), rgba(0, 0, 0, 0.55)), url("../img/forest_bg.jpg") no-repeat center;
    background-size: cover;
}

#navbar {
    transition: 0.4s;
}

.navbar-hidden {
    background: transparent;
}

.navbar-visible {
    background-color: #1c1d1f;
}



.nav-tabs .nav-item .nav-link {
    color: #FFF;
}

.nav-tabs .nav-item .nav-link.active {
    color: black;
}


.link-white {
    color: white;
    transition: 100ms;
}

.link-white:hover,
footer a:focus {
    color: lightgray;
}

.popup-hidden {
    visibility: hidden;
}
.popup-show {
    visibility: visible;
}