html,
body,
#intro {
  height: 100%;
}
body {
  position: relative;
}

#intro {
  background: url("../img/header-bg.jpg") no-repeat center center fixed;
  -webkit-background-size: cover;
  -moz-background-size: cover;
  -o-background-size: cover;
  background-size: cover;
}

.top-nav-collapse {
  background-color: #24355c;
}
.navbar.navbar-dark .navbar-nav .nav-item .nav-link.active {
  color: #fff;
  font-weight: bolder;
  transition: 0.35s;
  background: transparent;
  padding-top: 5px;
  border-top: 3px solid #45aed6;
}
@media (max-width: 768px) {
  .navbar:not(.top-nav-collapse) {
    background-color: #24355c;
  }
}

@media (min-width: 800px) and (max-width: 850px) {
  .navbar:not(.top-nav-collapse) {
    background-color: #24355c;
  }
}

* {
  box-sizing: border-box;
}

.imgbox {
  position: relative;
  width: 100%;
}

.image {
  display: block;
  width: 100%;
  height: auto;
}

.imgoverlay {
  position: absolute;
  bottom: 0;
  background: rgb(0, 0, 0);
  background: rgba(0, 0, 0, 0.5);
  /* Black see-through */
  color: #f1f1f1;
  width: 100%;
  transition: 0.5s ease;
  opacity: 0;
  color: white;
  font-size: 20px;
  padding: 20px;
  text-align: center;
}

.imgbox:hover .imgoverlay {
  opacity: 1;
}