.skip-link {
    background: rgb(211, 211, 211);
    color: rgb(57, 52, 134);
    left: 50%;
    padding: 8px;
    position: absolute;
    transform: translateY(-100%);
    transition: transform 0.3s;
}
  
.skip-link:focus {
    transform: translateY(0%);
}

.credit-line {
    margin: 1rem 0;
}

/* headings */

.sr-only {
    position:absolute;
    left:-10000px;
    top:auto;
    width:1px;
    height:1px;
    overflow:hidden;
}

hgroup:after {
    display: block;
    max-width: 100px;
    margin-top: 1rem;
    border-bottom: 0.125rem solid var(--primary);
    content: "";
}

/* buttons */

article > footer > a {
    margin: 0.5em;
}

article > footer > a:hover {
    background-color: #1095c1;
}

/* metadata */

details summary, details > dl > dt {
    text-transform: uppercase;
    font-weight: bold;
}

details[open]>summary:not(:focus) {
    color: var(--primary);
}

/* book cover */

.book-cover-container {
    display: grid;
    grid-template-columns: repeat(2, 1fr);
    grid-template-rows: 1fr;
    grid-column-gap: 0px;
    grid-row-gap: 0px;
}

.title-card {
    height: 90vh;
    padding: 5rem;
    display: grid;
    grid-template-columns: repeat(2, 1fr);
    grid-template-rows: 1fr;
    grid-column-gap: 24px;
    grid-row-gap: 0px;
}

.title-card-body {
    top: 50%;
}

.title-card-cover img {
        width: 50%;
        height: auto;
}