/* general header */

.header-container {
    display: flex;
	position: fixed; /* always at top */
	top: 0;
	height: 32px;
	width: 100%;
    align-items: center;
    justify-content: space-between;
    background-color: var(--header-bg-color);
    padding: 10px 0px;
    border-bottom-left-radius: 20px;
	border-bottom-right-radius: 20px;
	box-shadow: 1px 1px 26px 1px rgba(0,0,0,0.62);
	z-index: 1000; /* in front of other content */
	transition: transform 0.3s, opacity 0.2s, margin 0.4s;
}

/* left header part (with icon and title) */

.header-left {
    display: flex;
    align-items: center;
}

.header-icon {
    margin: 10px;
}

.header-title a {
  font-size: 1.5em;
  font-weight: bold;
  text-decoration: none;
  color: var(--header-title-color);
}

.header-title a:hover {
  color: var(--header-title-hover-color);
}
/* right header part (with navigation and links) */

.header-nav {
    display: flex;
	color: var(--header-link-color);
    align-items: stretch;
    justify-content: center;
    list-style: none;
    padding: 0 20px;
    margin-bottom: 13px;
    z-index: 1001;
}

.header-nav-item {
    position: relative;
    flex: 1;
}

/* nav links (two versions: -extra) */

.header-nav-link {
    display: block;
    padding: 10px 20px;
    text-decoration: none;
    color: var(--header-link-color);
    font-size: 1em;
    transition: font-size 0.1s, color 0.1s, background-color 0.1s;
	border-radius: 20px;
    border-bottom: 2px;
}

.header-nav-item:hover .header-nav-link {
    background-color: var(--header-hover-bg-color);
    color: var(--header-hover-color);
    font-size: 1.05em;
	font-weight: 700;
}

/* tooltip */
.header-nav-link::before {
  content: attr(data-tooltip);
  font-size: 0.7em;
  position: absolute;
  bottom: 60%;
  left: 50%;
  transform: translateX(-50%);
  background-color: rgba(0, 0, 0, 0.8);
  color: #fff;
  padding: 5px 10px;
  border-radius: 5px;
  white-space: nowrap;
  opacity: 0;
  pointer-events: none;
  cursor: pointer;
  transition: opacity 0.2s ease-in-out;
  z-index: 1002;
}

.header-nav-link:hover::before {
  opacity: 1; 
  pointer-events: auto;
}

.header-nav-link-extra {
    display: block;
    padding: 9px;
	margin: 1px 25px 1px 15px;
    text-decoration: none;
	color: var(--header-link-color);
    font-size: 0.8em;
    transition: font-size 0.1s, color 0.1s, background-color 0.1s;
	border-radius: 100%;
}
.header-nav-item:hover .header-nav-link-extra {
    background-color: var(--header-hover-bg-color);
    color: var(--header-hover-color);
    font-size: 0.85em;
	font-weight: 700;
}

/* submenus */

.header-submenu {
    display: none;
    position: absolute;
    top: 100%;
    left: 0;
    background-color: var(--header-bg-color);
    padding: 0;
    border-bottom-left-radius: 20px;
	border-bottom-right-radius: 20px;
    box-shadow: 0 4px 6px rgba(0, 0, 0, 0.1);
}

.header-nav-item:hover .header-submenu {
    display: block;
}

.header-submenu-item {
    list-style: none;
}

.header-submenu-link {
    display: block;
    padding: 10px 20px;
    text-decoration: none;
    color: var(--header-link-color);
    font-size: 0.9em;
    transition: color 0.1s, background-color 0.1s, font-size 0.1s;
}

.header-submenu-link:hover {
    background-color: var(--header-hover-bg-color);
    color: var(--header-hover-color);
	font-weight: 700;
	font-size: 1.01em;
}

.header-nav-link.current-page {
    border-radius: 0px;
    border-top-left-radius: 20px;
    border-top-right-radius: 20px;
    border-bottom: 2px solid black;
    padding: 9.5px 20px;
}
.header-nav-link-extra.current-page {
    background-color: var(--header-hover-bg-color);
}
.header-submenu-link.current-page {
    font-weight: 700;
}