.prt-main {
    max-width: 1200px;
    margin: 0 auto;
    padding: 60px 40px 100px;
}

/* ── Hero ── */
.prt-hero { margin-bottom: 52px; }

.prt-label {
    font-size: 11px;
    font-weight: 700;
    letter-spacing: .2em;
    text-transform: uppercase;
    color: var(--navy);
    display: block;
    margin-bottom: 12px;
}

.prt-title {
    font-family: var(--serif);
    font-size: clamp(36px, 5vw, 56px);
    font-weight: 800;
    color: var(--text);
    margin-bottom: 10px;
    line-height: 1.1;
}

.prt-sub {
    font-size: 16px;
    color: var(--muted);
}

/* ── Layout ── */
.prt-layout {
    display: block;
}

/* ── Sidebar ── */
.prt-sidebar {
    display: flex;
    flex-direction: column;
    gap: 8px;
    position: sticky;
    top: 24px;
}

.prt-tab {
    display: flex;
    align-items: center;
    gap: 12px;
    padding: 12px 16px;
    border: 1px solid var(--gray);
    background: white;
    cursor: pointer;
    transition: .15s;
    text-align: left;
    font-family: var(--sans);
    font-size: 14px;
    font-weight: 500;
    color: var(--text);
}

.prt-tab:hover { background: #f5f6fb; }

.prt-tab--active {
    background: var(--navy);
    color: white;
    border-color: var(--navy);
}

.prt-tab-logo {
    height: 28px;
    width: auto;
    object-fit: contain;
    flex-shrink: 0;
    filter: none;
}

.prt-tab--active .prt-tab-logo {
    filter: brightness(0) invert(1);
}

.prt-loading, .prt-placeholder {
    font-size: 14px;
    color: var(--muted);
}

/* ── Detail ── */
.prt-detail {
    border: 1px solid var(--gray);
    padding: 40px;
    background: white;
}

.prt-detail-header {
    display: flex;
    gap: 32px;
    align-items: flex-start;
    padding-bottom: 32px;
    border-bottom: 1px solid var(--gray);
    margin-bottom: 36px;
}

.prt-detail-logo {
    height: 160px;
    width: auto;
    object-fit: contain;
    flex-shrink: 0;
}

.prt-detail-name {
    font-family: var(--serif);
    font-size: 28px;
    font-weight: 700;
    color: var(--text);
    margin-bottom: 10px;
}

.prt-detail-desc {
    font-size: 15px;
    line-height: 1.75;
    color: var(--muted);
    margin-bottom: 14px;
}

.prt-detail-link {
    font-size: 13px;
    font-weight: 600;
    color: var(--navy);
    text-decoration: none;
}
.prt-detail-link:hover { text-decoration: underline; }

/* ── Articles grid ── */
.prt-articles-title {
    font-size: 11px;
    font-weight: 700;
    letter-spacing: .18em;
    text-transform: uppercase;
    color: var(--navy);
    margin-bottom: 20px;
}

.prt-articles-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(260px, 1fr));
    gap: 20px;
}

.prt-article-card {
    display: flex;
    flex-direction: column;
    border: 1px solid var(--gray);
    text-decoration: none;
    color: inherit;
    transition: box-shadow .2s, transform .2s;
}

.prt-article-card:hover {
    box-shadow: 0 6px 24px rgba(26,31,143,.1);
    transform: translateY(-2px);
}

.prt-article-img {
    height: 200px;
    background-size: cover;
    background-position: center 20%;
    flex-shrink: 0;
}

.prt-article-body {
    padding: 16px 18px 18px;
    display: flex;
    flex-direction: column;
    gap: 6px;
    flex: 1;
}

.prt-article-tag {
    font-size: 10px;
    font-weight: 700;
    letter-spacing: .15em;
    text-transform: uppercase;
    color: var(--navy);
}

.prt-article-title {
    font-family: var(--serif);
    font-size: 15px;
    font-weight: 700;
    line-height: 1.35;
    color: var(--text);
}

.prt-article-excerpt {
    font-size: 13px;
    color: var(--muted);
    line-height: 1.55;
    flex: 1;
}

.prt-article-author {
    font-size: 11px;
    color: var(--muted);
    margin-top: 4px;
    padding-top: 10px;
    border-top: 1px solid var(--gray);
}

@media (max-width: 768px) {
    .prt-main { padding: 40px 20px 60px; }
    .prt-layout { grid-template-columns: 1fr; }
    .prt-sidebar { position: static; flex-direction: row; flex-wrap: wrap; }
    .prt-detail { padding: 24px; }
    .prt-detail-header { flex-direction: column; gap: 16px; }
}