/* Knowledge Hub Page specific styling */

.hub-hero {
  background: linear-gradient(135deg, var(--color-primary-light) 0%, #ffffff 100%);
  padding: 11rem 0 5rem 0;
  text-align: center;
  border-bottom: 1px solid var(--color-border);
}

.hub-hero-subtitle {
  font-family: var(--font-body);
  font-size: 0.85rem;
  font-weight: 700;
  color: var(--color-accent);
  text-transform: uppercase;
  letter-spacing: 0.1em;
  display: block;
  margin-bottom: 0.75rem;
}

.hub-hero-title {
  margin-bottom: 1.25rem;
  font-size: clamp(2.2rem, 5vw, 3.5rem);
}

.hub-hero-desc {
  max-width: 600px;
  margin: 0 auto;
  font-size: 1.05rem;
  color: var(--color-text-muted);
}

/* Hub Controls: Search and Filters */
.hub-controls {
  margin-top: -2.5rem;
  position: relative;
  z-index: 10;
  margin-bottom: 4rem;
}

.search-filter-container {
  background: var(--color-card-bg);
  border: 1px solid var(--color-border);
  border-radius: 20px;
  box-shadow: var(--shadow-md);
  padding: 1.5rem;
  display: flex;
  flex-direction: column;
  gap: 1.5rem;
}

@media (min-width: 768px) {
  .search-filter-container {
    padding: 2rem;
  }
}

.search-bar-wrapper {
  position: relative;
  width: 100%;
}

.search-input {
  width: 100%;
  padding: 1rem 1.25rem 1rem 3rem;
  font-family: var(--font-body);
  font-size: 1rem;
  border: 1px solid var(--color-border);
  border-radius: 50px;
  outline: none;
  background-color: var(--color-primary-light);
  transition: all var(--transition-fast);
  color: var(--color-text-dark);
}

.search-input:focus {
  border-color: var(--color-primary);
  background-color: #ffffff;
  box-shadow: 0 0 0 4px var(--color-primary-glow);
}

.search-icon {
  position: absolute;
  left: 1.15rem;
  top: 50%;
  transform: translateY(-50%);
  color: var(--color-text-muted);
  pointer-events: none;
}

.categories-filter-wrapper {
  width: 100%;
  display: flex;
  flex-direction: column;
  gap: 0.75rem;
}

.filter-label {
  font-family: var(--font-body);
  font-size: 0.82rem;
  font-weight: 700;
  color: var(--color-text-muted);
  text-transform: uppercase;
  letter-spacing: 0.05em;
}

.categories-list {
  display: flex;
  flex-wrap: wrap;
  gap: 0.75rem 0.5rem;
}

.category-pill {
  padding: 0.5rem 1.25rem;
  font-family: var(--font-body);
  font-size: 0.88rem;
  font-weight: 500;
  border-radius: 50px;
  background-color: var(--color-primary-light);
  color: var(--color-primary-dark);
  border: 1px solid transparent;
  cursor: pointer;
  transition: all var(--transition-fast);
}

.category-pill:hover {
  background-color: var(--color-primary);
  color: var(--color-text-light);
}

.category-pill.active {
  background-color: var(--color-primary-dark);
  color: var(--color-text-light);
  box-shadow: 0 4px 10px var(--color-primary-glow);
}

/* Featured Article Section */
.featured-section {
  margin-bottom: 4rem;
}

.featured-card {
  display: grid;
  grid-template-columns: 1fr;
  background: var(--color-card-bg);
  border: 1px solid var(--color-border);
  border-radius: 24px;
  box-shadow: var(--shadow-sm);
  overflow: hidden;
  transition: all var(--transition-normal);
}

.featured-card:hover {
  transform: translateY(-4px);
  box-shadow: var(--shadow-md);
  border-color: var(--color-primary);
}

@media (min-width: 992px) {
  .featured-card {
    grid-template-columns: 1.2fr 1fr;
  }
}

.featured-image-wrapper {
  position: relative;
  min-height: 250px;
  overflow: hidden;
}

@media (min-width: 992px) {
  .featured-image-wrapper {
    min-height: 400px;
  }
}

.featured-image {
  width: 100%;
  height: 100%;
  object-fit: cover;
  transition: transform var(--transition-slow);
}

.featured-card:hover .featured-image {
  transform: scale(1.03);
}

.featured-badge {
  position: absolute;
  top: 1.5rem;
  left: 1.5rem;
  background: var(--color-accent);
  color: var(--color-text-light);
  font-family: var(--font-body);
  font-size: 0.75rem;
  font-weight: 700;
  text-transform: uppercase;
  padding: 0.35rem 0.85rem;
  border-radius: 50px;
  letter-spacing: 0.05em;
}

.featured-content {
  padding: 2rem;
  display: flex;
  flex-direction: column;
  justify-content: center;
}

@media (min-width: 992px) {
  .featured-content {
    padding: 3rem;
  }
}

.featured-label {
  font-size: 0.8rem;
  font-weight: 700;
  color: var(--color-accent);
  text-transform: uppercase;
  letter-spacing: 0.08em;
  margin-bottom: 0.75rem;
}

.featured-title {
  font-size: clamp(1.6rem, 3vw, 2.2rem);
  margin-bottom: 1.25rem;
  line-height: 1.25;
}

.featured-desc {
  font-size: 1rem;
  line-height: 1.6;
  color: var(--color-text-muted);
  margin-bottom: 2rem;
}

.featured-meta {
  display: flex;
  gap: 1rem;
  font-family: var(--font-body);
  font-size: 0.85rem;
  color: var(--color-text-muted);
  margin-bottom: 2rem;
  align-items: center;
}

.featured-meta-dot {
  font-size: 0.5rem;
  color: var(--color-border);
}

/* Articles Grid */
.articles-grid-section {
  margin-bottom: 6rem;
}

.grid-header {
  margin-bottom: 2rem;
  display: flex;
  justify-content: space-between;
  align-items: center;
  border-bottom: 1px solid var(--color-border);
  padding-bottom: 1rem;
}

.grid-header-title {
  font-size: 1.6rem;
  font-weight: 500;
}

.results-count {
  font-family: var(--font-body);
  font-size: 0.9rem;
  color: var(--color-text-muted);
}

.articles-grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: 2rem;
}

@media (min-width: 768px) {
  .articles-grid {
    grid-template-columns: repeat(2, 1fr);
  }
}

@media (min-width: 992px) {
  .articles-grid {
    grid-template-columns: repeat(3, 1fr);
  }
}

.article-card {
  background: var(--color-card-bg);
  border: 1px solid var(--color-border);
  border-radius: 20px;
  overflow: hidden;
  box-shadow: var(--shadow-sm);
  display: flex;
  flex-direction: column;
  height: 100%;
  transition: all var(--transition-normal);
}

.article-card:hover {
  transform: translateY(-5px);
  box-shadow: var(--shadow-md);
  border-color: var(--color-primary);
}

.card-img-wrapper {
  position: relative;
  height: 200px;
  overflow: hidden;
  background-color: var(--color-primary-light);
}

.card-img {
  width: 100%;
  height: 100%;
  object-fit: cover;
  transition: transform var(--transition-slow);
}

.article-card:hover .card-img {
  transform: scale(1.05);
}

.card-badge {
  position: absolute;
  top: 1rem;
  left: 1rem;
  background: rgba(255, 255, 255, 0.95);
  color: var(--color-primary-dark);
  font-family: var(--font-body);
  font-size: 0.72rem;
  font-weight: 600;
  text-transform: uppercase;
  padding: 0.25rem 0.75rem;
  border-radius: 50px;
  border: 1px solid var(--color-border);
  letter-spacing: 0.02em;
}

.card-body-content {
  padding: 1.75rem;
  display: flex;
  flex-direction: column;
  flex: 1;
}

.card-meta {
  display: flex;
  gap: 0.75rem;
  font-family: var(--font-body);
  font-size: 0.78rem;
  color: var(--color-text-muted);
  margin-bottom: 0.75rem;
  align-items: center;
}

.card-meta-dot {
  font-size: 0.4rem;
  color: var(--color-border);
}

.card-title-text {
  font-size: 1.25rem;
  margin-bottom: 0.85rem;
  line-height: 1.35;
  color: var(--color-primary-dark);
  display: -webkit-box;
  -webkit-line-clamp: 2;
  -webkit-box-orient: vertical;
  overflow: hidden;
  min-height: 2.7rem;
}

.card-excerpt-text {
  font-size: 0.92rem;
  line-height: 1.5;
  color: var(--color-text-muted);
  margin-bottom: 1.5rem;
  display: -webkit-box;
  -webkit-line-clamp: 3;
  -webkit-box-orient: vertical;
  overflow: hidden;
  min-height: 4.14rem;
}

.card-cta-wrapper {
  margin-top: auto;
  border-top: 1px solid var(--color-border);
  padding-top: 1.25rem;
}

.card-read-link {
  display: flex;
  align-items: center;
  justify-content: space-between;
  font-family: var(--font-body);
  font-size: 0.88rem;
  font-weight: 600;
  color: var(--color-primary);
  transition: color var(--transition-fast);
}

.article-card:hover .card-read-link {
  color: var(--color-accent-dark);
}

/* Empty State */
.no-results {
  text-align: center;
  padding: 4rem 2rem;
  background: var(--color-card-bg);
  border: 1px solid var(--color-border);
  border-radius: 24px;
  width: 100%;
}

.no-results-icon {
  font-size: 3rem;
  margin-bottom: 1rem;
  display: block;
}

.no-results h3 {
  font-size: 1.4rem;
  margin-bottom: 0.5rem;
}

.no-results p {
  color: var(--color-text-muted);
  margin-bottom: 1.5rem;
}

/* Hub CTA Widget */
.hub-cta-section {
  margin-bottom: 6rem;
}

.hub-cta-card {
  background: linear-gradient(135deg, var(--color-primary) 0%, var(--color-primary-dark) 100%);
  color: var(--color-text-light);
  border-radius: 24px;
  padding: 3rem 2rem;
  text-align: center;
  box-shadow: var(--shadow-md);
  position: relative;
  overflow: hidden;
}

@media (min-width: 768px) {
  .hub-cta-card {
    padding: 4rem;
  }
}

.hub-cta-card h2 {
  color: var(--color-text-light);
  font-size: 2.2rem;
  margin-bottom: 1rem;
}

.hub-cta-card p {
  color: rgba(255, 255, 255, 0.85);
  max-width: 600px;
  margin: 0 auto 2.5rem auto;
  font-size: 1.05rem;
}

.hub-cta-buttons {
  display: flex;
  gap: 1rem;
  justify-content: center;
  flex-wrap: wrap;
}

/* Layout Wrapper for Sidebar Directory & Main Grid */
.hub-content-wrapper {
  display: grid;
  grid-template-columns: 1fr;
  gap: 2.5rem;
  margin-top: 2rem;
  align-items: start;
}

@media (min-width: 992px) {
  .hub-content-wrapper {
    grid-template-columns: 280px 1fr;
  }
}

/* Sidebar Directory Pane styling */
.hub-sidebar {
  display: block;
}

.sidebar-card {
  background-color: var(--color-primary-dark);
  border: 1px solid rgba(255, 255, 255, 0.08);
  border-radius: 20px;
  padding: 1.75rem 1.5rem;
  box-shadow: var(--shadow-md);
  position: sticky;
  top: 7rem;
  max-height: 80vh;
  overflow-y: auto;
  color: var(--color-text-light);
}

/* Custom Scrollbar for Sidebar */
.sidebar-card::-webkit-scrollbar {
  width: 5px;
}
.sidebar-card::-webkit-scrollbar-track {
  background: transparent;
}
.sidebar-card::-webkit-scrollbar-thumb {
  background: rgba(255, 255, 255, 0.15);
  border-radius: 10px;
}
.sidebar-card::-webkit-scrollbar-thumb:hover {
  background: rgba(255, 255, 255, 0.3);
}

.sidebar-title {
  font-family: var(--font-heading);
  font-size: 1.3rem;
  font-style: italic;
  color: var(--color-accent-light);
  margin-bottom: 1.5rem;
  border-bottom: 1px solid rgba(255, 255, 255, 0.08);
  padding-bottom: 0.75rem;
}

.sidebar-group-item {
  margin-bottom: 0.5rem;
  display: flex;
  flex-direction: column;
}

.sidebar-group-header {
  font-family: var(--font-body);
  font-size: 0.78rem;
  font-weight: 700;
  color: rgba(255, 255, 255, 0.65);
  text-transform: uppercase;
  letter-spacing: 0.08em;
  padding: 0.55rem 0.75rem;
  cursor: pointer;
  display: flex;
  justify-content: space-between;
  align-items: center;
  border-radius: 8px;
  background-color: rgba(255, 255, 255, 0.02);
  border: 1px solid rgba(255, 255, 255, 0.03);
  transition: all var(--transition-fast);
  user-select: none;
}

.sidebar-group-header:hover {
  background-color: rgba(255, 255, 255, 0.06);
  color: #ffffff;
  border-color: rgba(255, 255, 255, 0.08);
}

.sidebar-group-chevron {
  width: 12px;
  height: 12px;
  fill: none;
  stroke: currentColor;
  stroke-width: 2.5;
  stroke-linecap: round;
  stroke-linejoin: round;
  transition: transform var(--transition-normal);
  color: rgba(255, 255, 255, 0.4);
}

.sidebar-group-header:hover .sidebar-group-chevron {
  color: #ffffff;
}

/* Subcategory Links */
.sidebar-group-links-list {
  list-style: none;
  padding: 0.4rem 0 0 0.5rem;
  margin: 0;
  display: flex;
  flex-direction: column;
  gap: 0.35rem;
  overflow: hidden;
  max-height: 500px;
  opacity: 1;
  transition: max-height 0.35s cubic-bezier(0.16, 1, 0.3, 1),
              opacity 0.35s cubic-bezier(0.16, 1, 0.3, 1),
              padding 0.35s cubic-bezier(0.16, 1, 0.3, 1);
}

/* Collapsed state */
.sidebar-group-item.collapsed .sidebar-group-links-list {
  max-height: 0;
  opacity: 0;
  padding-top: 0;
  padding-bottom: 0;
  pointer-events: none;
}

.sidebar-group-item.collapsed .sidebar-group-chevron {
  transform: rotate(-90deg);
}

.sidebar-group-links-list li {
  line-height: 1.35;
}

.sidebar-article-nav-link {
  color: rgba(255, 255, 255, 0.75);
  font-size: 0.82rem;
  text-decoration: none;
  transition: all var(--transition-fast);
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 0.35rem 0.5rem;
  border-radius: 6px;
  width: 100%;
}

.sidebar-article-nav-link:hover {
  color: var(--color-accent-light);
  background-color: rgba(255, 255, 255, 0.04);
  padding-left: 0.75rem;
}

.article-icon-bullet {
  width: 6px;
  height: 6px;
  fill: var(--color-accent);
  opacity: 0.6;
  flex-shrink: 0;
  transition: transform var(--transition-fast);
}

.sidebar-article-nav-link:hover .article-icon-bullet {
  transform: scale(1.3);
  opacity: 1;
}

/* ============================================
   MOBILE RESPONSIVE ENHANCEMENTS
   ============================================ */
@media (max-width: 768px) {
  .hub-hero {
    padding: 6.5rem 1rem 3rem 1rem;
  }
  .hub-controls {
    margin-top: -1.5rem;
    margin-bottom: 2.5rem;
  }
  .categories-list {
    flex-wrap: nowrap;
    overflow-x: auto;
    -webkit-overflow-scrolling: touch;
    padding-bottom: 0.5rem;
    scrollbar-width: none;
    -ms-overflow-style: none;
  }
  .categories-list::-webkit-scrollbar {
    display: none;
  }
  .category-pill {
    flex-shrink: 0;
    white-space: nowrap;
    padding: 0.45rem 1rem;
    font-size: 0.82rem;
  }
  .search-filter-container {
    padding: 1.25rem 1rem;
    border-radius: 16px;
  }
  .featured-content {
    padding: 1.5rem 1.25rem;
  }
  .featured-title {
    font-size: 1.45rem;
  }
  .featured-desc {
    font-size: 0.92rem;
    margin-bottom: 1.25rem;
  }
  .card-body-content {
    padding: 1.25rem;
  }
}