header {
    position: fixed;
    top: 0.5rem;
    left: 0.5rem;
    width: calc(100% - 1rem);
    height: 4rem;
    background-color: rgba(0, 0, 0, 0.5);
    border-radius: 999px;
    z-index: 10;
    transition: 300ms;
}

header nav {
    display: flex;
    flex-direction: row;
    flex-wrap: nowrap;
    align-items: center;
    justify-items: start;
    justify-content: start;
    position: absolute;
    top: 0px;
    left: 0px;
    width: 100%;
    height: 100%;
    gap: 1rem;
    padding-left: 1rem;
    padding-left: 1rem;
}

header nav a,
header nav a:visited {
    position: relative;
    color: rgb(209, 255, 242);
    text-decoration: none;
    font-weight: bold;
    font-size: 1.25rem;
}

header nav a::after {
    content: "";
    position: absolute;
    bottom: 0px;
    left: 0px;
    width: 0%;
    transition: 200ms;
    height: 0.1rem;
    background-color: rgb(209, 255, 242);
}

header nav a:hover::after {
    width: 100%;
}