.topheader{
    box-shadow: 0 4px 5px var(--navbar-shallow-color);
    position: fixed;
    background-color: var(--secundary-color);
    left: 0;
    top: 0;
    width: 100%;
    z-index: 100;
}

.topnav{
    display: flex;
    justify-content: space-between;
    padding: 15px;
    max-width: 1600px;
    margin: 0 auto;
}

/* logo */

.logo {
    width: 350px;
    margin-left: 5px;
}

.logo img {
    width: 75%;
    margin-top: 10px;

}

/* menu */

.menu{
    display: flex;
    list-style: none;
    margin: 0;
    padding: 0;
}

.menu li {
    padding: 0 30px;
}

.menu a{
    font-size: 18px;
    font-weight: 600;
    line-height: 100px;
    text-transform: uppercase;
    position: relative;
}

.menu a::after{
    content: "";
    background-color: var(--primary-color);
    position: absolute;
    left: 0;
    top: calc(100% + 4px);
    width: 100%;
    height: 4px;

    opacity: 0;
    transition: opacity 0.3s;
}

.menu a.selected::after,
.menu a:hover::after {
  opacity: 0.8;
}

.menu a:hover {
    color: var(--primary-color);
}