.related-materials {
    margin-top: 2rem;
    border: 1px solid var(--border-color, #e0e0e0);
    border-radius: 12px;
    padding: 1.5rem;
    background: var(--card-bg, #fff);
    box-shadow: 0 8px 24px rgba(0, 0, 0, 0.04);
}

.related-materials__header {
    display: flex;
    align-items: center;
    justify-content: space-between;
    margin-bottom: 1rem;
}

.related-materials__title {
    font-size: 1.35rem;
    font-weight: 700;
    margin: 0;
}

.related-materials__groups {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(220px, 1fr));
    gap: 1.25rem;
}

.related-group {
    border-radius: 10px;
    border: 1px solid var(--border-subtle, #f0f0f0);
    padding: 1rem;
    background: var(--card-subtle, #fafafa);
}

.related-group__title {
    font-size: 1.05rem;
    margin: 0 0 0.4rem;
}

.related-group__description {
    margin: 0 0 0.75rem;
    color: var(--text-muted, #666);
    font-size: 0.9rem;
}

.related-group__list {
    list-style: none;
    margin: 0;
    padding: 0;
    display: grid;
    gap: 0.75rem;
}

.related-item {
    display: flex;
    align-items: flex-start;
    gap: 0.5rem;
}

.related-item__link {
    flex: 1;
    text-decoration: none;
    color: var(--text-primary, #1e1e1e);
}

.related-item__link:hover .related-item__title {
    text-decoration: underline;
}

.related-item__title {
    font-weight: 600;
    display: block;
}

.related-item__subtitle {
    display: block;
    font-size: 0.85rem;
    color: var(--text-muted, #666);
    margin-top: 0.15rem;
}

.related-item__badge {
    font-size: 0.9rem;
    color: var(--text-muted, #999);
}

.related-item__note {
    display: block;
    margin-left: auto;
    font-size: 0.8rem;
    color: var(--text-muted, #888);
}

@media (max-width: 768px) {
    .related-materials {
        padding: 1.25rem;
    }

    .related-materials__groups {
        grid-template-columns: 1fr;
    }
}