/* Content headings — smaller than browser defaults; body is 1.6rem (16px). */

#mdbook-content h1 {
    font-size: 2.15rem; /* ~21.5px */
    margin-block-start: 0.5em;
    margin-block-end: 0.35em;
}

#mdbook-content h2 {
    font-size: 1.85rem; /* ~18.5px */
    margin-block-start: 1.0em;
    margin-block-end: 0.3em;
}

#mdbook-content h3 {
    font-size: 1.68rem; /* ~16.8px; still above body */
    margin-block-start: 0.9em;
    margin-block-end: 0.25em;
}

.book-logo {
    width: 11rem;      /* ~176px; try 9–14rem */
    max-width: 40%;
    height: auto;
    display: block;
    margin: 0 auto 1.25rem;
}