.header-main {
    width: 100%;
    height: var(--header-height);
    background-color: var(--header-color);
    display: flex;
    justify-content: space-between;
    position: fixed;
    top: 0;
    z-index: 100;
}

.header-main-logo {
    width: fit-content;
    height: 100%;
    padding-left: calc(var(--header-height) / 2);
    display: flex;
}

.header-main-logo img {
    height: calc(var(--header-height) / 1.5);
    align-self: center;
}

.header-main-nav {
    display: flex;
    width: fit-content;
    height: 100%;
}

.header-main-nav ul {
    height: 100%;
    /* padding-left: 40px; */
    display: flex;
    align-self: center;
    list-style: none;
    margin-left: 30px;
}

.header-main-nav ul li {
    position: relative;
    /* display: inline;
    float: left; */
}

.header-main-nav ul li a {
    padding: 0 10px 0 10px;
    font-size: 16px;
    font-family: Georgia, 'Times New Roman', Times, serif;
    line-height: var(--header-height);
    background-color: white;
    color: black;
    display: block;
    height: 100%;
    transition: all ease-in-out 100ms;
}

.header-main-nav ul li a:hover {
    background-color: var(--site-color-01-hover);
    color: var(--pitt-blue);
}


/* DROPDOWN STYLING */
.header-main ul li ul {
    visibility: hidden;
    opacity: 0;
    display: none;
    position: absolute;
    left: -30px;
    transition: all ease-in-out 100ms;
}

.header-main ul li ul li a {
    white-space: nowrap;
}

ul li:hover>ul {
    visibility: visible;
    opacity: 1;
    display: block;
}


/* SOCIAL MEDIA STYLING */
.header-main-sm {
    width: fit-content;
    height: 100%;
    padding-right: calc(var(--header-height) / 2);
    display: flex;
    align-items: center;
    column-gap: calc(var(--header-height) / 2);
}

.header-main-sm-linkedin {
    width: calc(var(--header-height) / 1.5);
    height: calc(var(--header-height) / 1.5);
    background-image: url(../img/linkedin_logo_02.png);
    background-repeat: no-repeat;
    background-size: cover;
}

.header-main-sm-scholar {
    width: calc(var(--header-height) / 1.5);
    height: calc(var(--header-height) / 1.5);
    background-image: url(../img/Google_Scholar_logo.svg.png);
    background-repeat: no-repeat;
    background-size: cover;
}

.header-main-sm-research-gate {
    width: calc(var(--header-height) / 1.5);
    height: calc(var(--header-height) / 1.5);
    background-image: url(../img/RG_Logo.02_Black.White.png);
    background-repeat: no-repeat;
    background-size: cover;
}