/* ══════════════════════════════════════════════════════════════
   Content pages — changelog.html and about.html.
   - Changelog timeline: entries live only in changelog.html (the home
     page lists the newest three as headlines, styled in index.html).
   - About page: data-source grid, citation list, contact card.
   Uses the theme tokens every page defines (--navy, --navy-mid, --text,
   --slate, --blue, --blue-light, --border, --border-light, --um-orange,
   --um-green, --cyan, --surface, --surface-raised, --radius, ...).
   ══════════════════════════════════════════════════════════════ */
.changelog-list {
    max-width: 780px;
    margin: 0 auto;
    position: relative;
    padding-left: 1rem;
}
.changelog-list::before {
    content: '';
    position: absolute;
    left: 6px;
    top: 6px;
    bottom: 6px;
    width: 1px;
    background: var(--border-light);
}
.changelog-entry {
    position: relative;
    display: grid;
    grid-template-columns: 110px 1fr;
    gap: 1.25rem;
    padding: 0.75rem 0 0.75rem 1.25rem;
    align-items: baseline;
}
.changelog-entry::before {
    content: '';
    position: absolute;
    left: -0.25rem;
    top: 1.1rem;
    width: 9px;
    height: 9px;
    border-radius: 50%;
    background: var(--um-orange);
    box-shadow: 0 0 0 3px var(--navy);
}
.changelog-entry:not(:first-child)::before {
    background: var(--slate);
    box-shadow: 0 0 0 3px var(--navy);
}
.changelog-date {
    font-size: 0.72rem;
    font-weight: 600;
    color: var(--slate);
    letter-spacing: 0.06em;
    text-transform: uppercase;
    white-space: nowrap;
    font-variant-numeric: tabular-nums;
}
.changelog-text {
    font-size: 0.92rem;
    color: var(--text);
    line-height: 1.6;
}
.changelog-text strong { color: var(--blue-light); font-weight: 600; }
.changelog-text a {
    color: var(--blue);
    text-decoration: underline;
    text-decoration-thickness: 1px;
    text-underline-offset: 2px;
    transition: color 0.15s;
}
.changelog-text a:hover { color: var(--cyan); }
.changelog-footer {
    text-align: center;
    margin-top: 1.5rem;
    font-size: 0.82rem;
    color: var(--slate);
}
.changelog-footer a {
    color: var(--blue-light);
    text-decoration: none;
    border-bottom: 1px dotted currentColor;
    transition: color 0.2s, border-color 0.2s;
}
.changelog-footer a:hover { color: var(--cyan); border-color: var(--cyan); }
@media (max-width: 600px) {
    .changelog-entry {
        grid-template-columns: 1fr;
        gap: 0.25rem;
        padding-left: 1rem;
    }
    .changelog-date { font-size: 0.68rem; }
    .changelog-text { font-size: 0.85rem; }
}

/* ── About page ─────────────────────────────────────────────── */
.about-page { padding-top: 0.5rem; }
.about-toc {
    display: flex;
    flex-wrap: wrap;
    justify-content: center;
    gap: 6px 10px;
    max-width: 900px;
    margin: 1.75rem auto 0;
    padding: 0 24px;
}
.about-toc a {
    font-size: 0.8rem;
    font-weight: 500;
    color: var(--slate);
    text-decoration: none;
    padding: 5px 12px;
    border: 1px solid var(--border-light);
    border-radius: 999px;
    transition: color 0.15s, border-color 0.15s;
}
.about-toc a:hover { color: var(--text); border-color: var(--um-green); }
.about-page section { scroll-margin-top: 64px; }
.about-page #about .content-section { padding-top: 2.5rem; }
.about-page .section-desc a, .about-page .source-card a { color: var(--blue); }

/* Data source grid */
.source-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
    gap: 1.25rem;
    margin-top: 2rem;
}
.source-card {
    background: var(--navy-mid);
    border: 1px solid var(--border);
    border-radius: var(--radius);
    padding: 1.5rem;
}
.source-card h3 { color: var(--text); margin-bottom: 0.5rem; font-size: 0.95rem; }
.source-card p { color: var(--slate); font-size: 0.85rem; line-height: 1.6; }
.source-card a { color: var(--blue); text-decoration: none; }
.source-card a:hover { text-decoration: underline; }

/* Citations */
.cite-list { display: flex; flex-direction: column; gap: 1rem; max-width: 840px; margin: 0 auto; }
.cite-pub { background: var(--navy-mid); border: 1px solid var(--border); border-radius: var(--radius); padding: 1.25rem 1.5rem; }
.cite-pub-label { font-size: 0.7rem; font-weight: 700; text-transform: uppercase; letter-spacing: 0.06em; color: var(--text-dim); margin-bottom: 0.5rem; }
.cite-pub-text { font-size: 0.875rem; line-height: 1.7; color: var(--slate); font-family: 'JetBrains Mono', monospace; word-break: break-word; }
.cite-pub-text a { color: var(--blue); text-decoration: none; }
.cite-pub-text a:hover { text-decoration: underline; }
.cite-pub-text em { font-style: italic; }
.cite-copy-landing { display: inline-flex; align-items: center; gap: 4px; margin-top: 0.75rem; padding: 4px 12px; font-size: 0.75rem; font-weight: 600; font-family: 'DM Sans', sans-serif; background: var(--surface); border: 1px solid var(--border-light); border-radius: 4px; color: var(--slate); cursor: pointer; transition: all 0.2s; }
.cite-copy-landing:hover { background: var(--um-green-tint); border-color: var(--um-green); color: var(--blue); }
.cite-copy-landing.copied { background: rgba(34,150,100,0.12); border-color: rgba(34,150,100,0.4); color: #1e7a4e; }
.cite-bibtex-landing { display: inline-flex; align-items: center; gap: 6px; padding: 8px 20px; font-size: 0.875rem; font-weight: 600; font-family: 'DM Sans', sans-serif; background: var(--um-green); border: 1px solid var(--um-green); border-radius: 6px; color: #ffffff; cursor: pointer; transition: all 0.2s; }
.cite-bibtex-landing:hover { background: var(--um-green-deep); border-color: var(--um-green-deep); }
.cite-bibtex-landing.copied { background: rgba(34,150,100,0.12); border-color: rgba(34,150,100,0.4); color: #1e7a4e; }

/* Contact card (own class: the shared stylesheet's .contact-section
   title rule is white-on-light) */
.about-contact { background: var(--surface); border-top: 1px solid var(--border); text-align: center; padding: 4rem 24px; color: var(--text); }
.about-contact .section-title { color: var(--text); }
.about-contact .contact-info { max-width: 500px; margin: 2rem auto 0; background: var(--surface-raised); padding: 2rem; border-radius: var(--radius-lg); border: 1px solid var(--border); }
.about-contact .contact-info a { color: var(--blue); }
.about-disclaimer { margin: 12px auto 0; padding-top: 10px; border-top: 1px solid var(--border); font-size: 0.72rem; color: var(--text-dim); max-width: 700px; line-height: 1.5; }
@media (max-width: 768px) {
    .about-page .content-section { padding: 3rem 16px; }
    .about-page .section-title { font-size: 1.4rem; }
}