/* ==========================================================================
   IELTS CORE - Authentic Cambridge CDI Materials & Practice Catalog (Screenshot 4)
   ========================================================================== */

/* 1. Global Reset & Theme Variables */
:root {
  --vx-cat-bg: #f8fafc;
  --vx-cat-surface: #ffffff;
  --vx-cat-border: #e2e8f0;
  --vx-cat-border-focus: #10b981;
  --vx-cat-text: #0f172a;
  --vx-cat-text-muted: #64748b;
  --vx-cat-text-light: #94a3b8;
  --vx-cat-emerald-start: #2ec487;
  --vx-cat-emerald-end: #10b981;
  --vx-cat-gold: #fbbf24;
  --vx-cat-cta-start: #ff5722;
  --vx-cat-cta-end: #f43f5e;
}

body.materials-page {
  background-color: var(--vx-cat-bg);
  color: var(--vx-cat-text);
  font-family: 'DM Sans', -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
  margin: 0;
  padding: 0;
}

/* 2. Top Red Announcement Banner */
.vx-top-notification-banner {
  background: linear-gradient(90deg, #dc2626 0%, #e11d48 100%);
  color: #ffffff;
  font-size: 13.5px;
  font-weight: 500;
  padding: 8px 16px;
  text-align: center;
  position: relative;
  z-index: 100;
  box-shadow: 0 1px 3px rgba(0, 0, 0, 0.1);
}

.vx-top-notification-content {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  max-width: 1200px;
  margin: 0 auto;
  line-height: 1.4;
}

.vx-top-fire {
  font-size: 15px;
}

.vx-top-text {
  letter-spacing: 0.01em;
}

.vx-offer-countdown {
  display: inline-block;
  font-variant-numeric: tabular-nums;
  font-weight: 700;
  background: rgba(0, 0, 0, 0.2);
  padding: 2px 8px;
  border-radius: 4px;
  margin: 0 4px;
  letter-spacing: 0.04em;
}

.vx-top-claim-link {
  color: #ffffff;
  font-weight: 700;
  text-decoration: underline;
  text-underline-offset: 3px;
  transition: opacity 0.15s;
  margin-left: 4px;
}

.vx-top-claim-link:hover {
  opacity: 0.9;
}

/* 3. Main App Layout: 2 Columns (Left Sidebar + Content) */
.vx-catalog-shell {
  display: flex;
  min-height: calc(100vh - 40px);
  width: 100%;
}

/* 4. Left Sidebar Navigation */
.vx-catalog-sidebar {
  width: 260px;
  flex-shrink: 0;
  background: var(--vx-cat-surface);
  border-right: 1px solid var(--vx-cat-border);
  display: flex;
  flex-direction: column;
  position: sticky;
  top: 0;
  height: 100vh;
  overflow-y: auto;
  z-index: 40;
}

.vx-catalog-sidebar::-webkit-scrollbar {
  width: 5px;
}

.vx-catalog-sidebar::-webkit-scrollbar-thumb {
  background: #cbd5e1;
  border-radius: 4px;
}

/* Brand Header */
.vx-sidebar-brand {
  display: flex;
  align-items: center;
  gap: 12px;
  padding: 20px 24px;
  text-decoration: none;
  border-bottom: 1px solid var(--vx-cat-border);
}

.vx-sidebar-logo {
  height: 32px;
  width: auto;
  display: block;
}

.vx-sidebar-brand-title {
  font-size: 16px;
  font-weight: 800;
  color: var(--vx-cat-text);
  letter-spacing: 0.05em;
}

/* Sidebar Nav Groups */
.vx-sidebar-nav {
  display: flex;
  flex-direction: column;
  padding: 12px 0;
}

.vx-sidebar-section-title {
  font-size: 11px;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 0.06em;
  color: var(--vx-cat-text-light);
  padding: 14px 24px 6px;
}

.vx-sidebar-item {
  display: flex;
  align-items: center;
  gap: 12px;
  padding: 9px 24px;
  font-size: 13.5px;
  font-weight: 500;
  color: var(--vx-cat-text-muted);
  text-decoration: none;
  border-left: 3px solid transparent;
  transition: all 0.15s ease;
  cursor: pointer;
  background: none;
  border-top: none;
  border-right: none;
  border-bottom: none;
  text-align: left;
  width: 100%;
}

.vx-sidebar-item:hover {
  background: #f1f5f9;
  color: var(--vx-cat-text);
}

.vx-sidebar-item.active {
  background: #ecfdf5;
  color: #065f46;
  font-weight: 600;
  border-left-color: #10b981;
}

.vx-sidebar-icon {
  font-size: 16px;
  line-height: 1;
  display: flex;
  align-items: center;
  justify-content: center;
  width: 18px;
}

.vx-sidebar-badge {
  margin-left: auto;
  font-size: 11px;
  font-weight: 700;
  padding: 2px 7px;
  border-radius: 12px;
  background: #f1f5f9;
  color: #64748b;
}

.vx-sidebar-item.active .vx-sidebar-badge {
  background: #d1fae5;
  color: #047857;
}

.vx-sidebar-lock-icon {
  margin-left: auto;
  font-size: 13px;
  color: #94a3b8;
}

/* Sidebar Utilities Divider */
.vx-sidebar-divider {
  height: 1px;
  background: var(--vx-cat-border);
  margin: 10px 20px;
}

/* Sidebar User Profile Card */
.vx-sidebar-user-card {
  margin-top: auto;
  padding: 16px 20px;
  border-top: 1px solid var(--vx-cat-border);
  background: #fafafa;
  display: flex;
  align-items: center;
  gap: 12px;
}

.vx-user-avatar {
  width: 36px;
  height: 36px;
  border-radius: 50%;
  background: linear-gradient(135deg, #10b981, #059669);
  color: #ffffff;
  font-weight: 700;
  font-size: 14px;
  display: flex;
  align-items: center;
  justify-content: center;
  flex-shrink: 0;
  overflow: hidden;
}

.vx-user-avatar img {
  width: 100%;
  height: 100%;
  object-fit: cover;
}

.vx-user-info {
  display: flex;
  flex-direction: column;
  overflow: hidden;
  line-height: 1.25;
}

.vx-user-name {
  font-size: 13px;
  font-weight: 600;
  color: var(--vx-cat-text);
  white-space: nowrap;
  overflow: hidden;
  text-overflow: ellipsis;
}

.vx-user-email {
  font-size: 11px;
  color: var(--vx-cat-text-muted);
  white-space: nowrap;
  overflow: hidden;
  text-overflow: ellipsis;
}

.vx-user-logout-btn {
  margin-left: auto;
  background: none;
  border: none;
  color: #94a3b8;
  cursor: pointer;
  padding: 4px;
  display: flex;
  align-items: center;
  justify-content: center;
  border-radius: 4px;
  transition: color 0.15s, background 0.15s;
}

.vx-user-logout-btn:hover {
  color: #ef4444;
  background: #fee2e2;
}

/* 5. Main Content Panel */
.vx-catalog-main {
  flex: 1;
  padding: 24px 36px 60px;
  max-width: 1240px;
  margin: 0 auto;
  width: 100%;
  box-sizing: border-box;
}

/* Mobile Nav Toggle Button */
.vx-catalog-mobile-bar {
  display: none;
  align-items: center;
  justify-content: space-between;
  padding: 12px 16px;
  background: var(--vx-cat-surface);
  border-bottom: 1px solid var(--vx-cat-border);
  margin: -24px -36px 20px;
}

.vx-mobile-drawer-toggle {
  background: none;
  border: 1px solid var(--vx-cat-border);
  border-radius: 6px;
  padding: 6px 10px;
  display: flex;
  align-items: center;
  gap: 6px;
  font-size: 13px;
  font-weight: 600;
  color: var(--vx-cat-text);
  cursor: pointer;
}

/* Breadcrumb Navigation */
.vx-catalog-breadcrumb {
  display: flex;
  align-items: center;
  gap: 8px;
  font-size: 13px;
  color: var(--vx-cat-text-muted);
  margin-bottom: 22px;
}

.vx-catalog-breadcrumb a {
  color: var(--vx-cat-text-muted);
  text-decoration: none;
  transition: color 0.15s;
}

.vx-catalog-breadcrumb a:hover {
  color: var(--vx-cat-text);
}

.vx-catalog-breadcrumb .sep {
  color: #cbd5e1;
}

.vx-catalog-breadcrumb .current {
  color: var(--vx-cat-text);
  font-weight: 600;
}

/* Category Header Banner */
.vx-cat-header-wrap {
  display: flex;
  align-items: center;
  gap: 16px;
  margin-bottom: 24px;
}

.vx-cat-icon-badge {
  width: 46px;
  height: 46px;
  border-radius: 12px;
  background: #ecfdf5;
  color: #059669;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 24px;
  flex-shrink: 0;
  border: 1px solid #d1fae5;
}

.vx-cat-title-block {
  display: flex;
  flex-direction: column;
}

.vx-cat-title {
  font-size: 24px;
  font-weight: 700;
  color: var(--vx-cat-text);
  margin: 0 0 4px;
  letter-spacing: -0.01em;
}

.vx-cat-subtitle {
  font-size: 14px;
  color: var(--vx-cat-text-muted);
  margin: 0;
}

/* Quick Format Filter Tabs */
.vx-type-tabs {
  display: flex;
  align-items: center;
  gap: 8px;
  margin-bottom: 18px;
  overflow-x: auto;
  padding-bottom: 2px;
}

.vx-type-tab {
  display: inline-flex;
  align-items: center;
  gap: 7px;
  padding: 8px 16px;
  border-radius: 999px;
  border: 1.5px solid var(--vx-cat-border);
  background: var(--vx-cat-surface);
  color: var(--vx-cat-text-muted);
  font-size: 13px;
  font-weight: 650;
  cursor: pointer;
  transition: all 0.15s ease;
  white-space: nowrap;
  font-family: inherit;
}

.vx-type-tab:hover {
  background: #f8fafc;
  border-color: #cbd5e1;
  color: var(--vx-cat-text);
  transform: translateY(-1px);
}

.vx-type-tab.active {
  background: #245bc7;
  border-color: #245bc7;
  color: #ffffff;
  box-shadow: 0 4px 12px rgba(36,91,199, 0.25);
}

.vx-type-tab.active .material-symbols-outlined {
  color: #ffffff !important;
}

body.night-mode .vx-type-tab,
html[data-theme="dark"] .vx-type-tab {
  background: #313234;
  border-color: #444548;
  color: #d4d5d8;
}

body.night-mode .vx-type-tab.active,
html[data-theme="dark"] .vx-type-tab.active {
  background: #3f64ac;
  border-color: #3f64ac;
  color: #e1e2e5;
}

/* Search Bar Row */
.vx-search-row {
  display: flex;
  gap: 10px;
  margin-bottom: 16px;
}

.vx-search-input-wrap {
  flex: 1;
  position: relative;
  display: flex;
  align-items: center;
}

.vx-search-icon {
  position: absolute;
  left: 14px;
  color: var(--vx-cat-text-light);
  font-size: 18px;
  pointer-events: none;
}

.vx-search-input {
  width: 100%;
  height: 44px;
  padding: 0 40px 0 42px;
  border: 1px solid var(--vx-cat-border);
  border-radius: 8px;
  background: var(--vx-cat-surface);
  font-size: 14px;
  color: var(--vx-cat-text);
  box-shadow: 0 1px 2px rgba(0, 0, 0, 0.03);
  outline: none;
  transition: border-color 0.15s, box-shadow 0.15s;
}

.vx-search-input:focus {
  border-color: #10b981;
  box-shadow: 0 0 0 3px rgba(16, 185, 129, 0.15);
}

.vx-search-clear {
  position: absolute;
  right: 12px;
  background: none;
  border: none;
  font-size: 18px;
  color: #94a3b8;
  cursor: pointer;
  padding: 4px;
}

.vx-search-btn {
  height: 44px;
  padding: 0 24px;
  background: #0f172a;
  color: #ffffff;
  border: none;
  border-radius: 8px;
  font-size: 14px;
  font-weight: 600;
  cursor: pointer;
  display: flex;
  align-items: center;
  gap: 8px;
  transition: background 0.15s;
}

.vx-search-btn:hover {
  background: #1e293b;
}

/* 5 Filter Dropdowns Row */
.vx-filters-row {
  display: flex;
  gap: 10px;
  flex-wrap: wrap;
  margin-bottom: 20px;
}

.vx-filter-select {
  height: 38px;
  padding: 0 32px 0 14px;
  border: 1px solid var(--vx-cat-border);
  border-radius: 8px;
  background: var(--vx-cat-surface) url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' width='12' height='12' viewBox='0 0 24 24' fill='none' stroke='%2364748b' stroke-width='2.5' stroke-linecap='round' stroke-linejoin='round'%3E%3Cpolyline points='6 9 12 15 18 9'%3E%3C/polyline%3E%3C/svg%3E") no-repeat right 10px center;
  appearance: none;
  font-size: 13.5px;
  font-weight: 500;
  color: #334155;
  cursor: pointer;
  transition: border-color 0.15s;
  outline: none;
}

.vx-filter-select:hover,
.vx-filter-select:focus {
  border-color: #94a3b8;
}

/* Results Count */
.vx-results-count-bar {
  font-size: 13px;
  color: var(--vx-cat-text-muted);
  font-weight: 500;
  margin-bottom: 22px;
  display: flex;
  align-items: center;
  justify-content: space-between;
}

.vx-results-count-bar .vx-reset-link {
  color: #10b981;
  font-weight: 600;
  text-decoration: none;
  cursor: pointer;
  background: none;
  border: none;
  padding: 0;
  font-size: 13px;
}

.vx-results-count-bar .vx-reset-link:hover {
  text-decoration: underline;
}

/* 6. 3-Column Responsive Cards Grid */
.vx-cards-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 24px;
}

@media (max-width: 1080px) {
  .vx-cards-grid {
    grid-template-columns: repeat(2, 1fr);
  }
}

@media (max-width: 680px) {
  .vx-cards-grid {
    grid-template-columns: 1fr;
  }
}

/* Individual Card */
.vx-test-card {
  background: var(--vx-cat-surface);
  border-radius: 14px;
  border: 1px solid var(--vx-cat-border);
  overflow: hidden;
  display: flex;
  flex-direction: column;
  transition: transform 0.2s cubic-bezier(0.16, 1, 0.3, 1), box-shadow 0.2s cubic-bezier(0.16, 1, 0.3, 1), border-color 0.2s ease;
  box-shadow: 0 1px 3px rgba(0, 0, 0, 0.04);
}

.vx-test-card:hover {
  transform: translateY(-3px);
  box-shadow: 0 12px 24px -6px rgba(0, 0, 0, 0.08), 0 4px 8px -4px rgba(0, 0, 0, 0.04);
  border-color: #cbd5e1;
}

/* Top Card Graphic Banner */
.vx-card-graphic {
  height: 180px;
  position: relative;
  display: flex;
  flex-direction: column;
  justify-content: space-between;
  padding: 14px 16px;
  color: #ffffff;
  background: linear-gradient(135deg, var(--vx-cat-emerald-start) 0%, var(--vx-cat-emerald-end) 100%);
  overflow: hidden;
}

.vx-test-card.skill-listening .vx-card-graphic {
  background: linear-gradient(135deg, #38bdf8 0%, #0284c7 100%);
}

.vx-test-card.skill-writing .vx-card-graphic {
  background: linear-gradient(135deg, #a78bfa 0%, #7c3aed 100%);
}

.vx-test-card.skill-speaking .vx-card-graphic {
  background: linear-gradient(135deg, #f472b6 0%, #db2777 100%);
}

.vx-card-graphic-top {
  display: flex;
  justify-content: space-between;
  align-items: center;
  z-index: 2;
}

.vx-card-badge-max {
  font-size: 11px;
  font-weight: 800;
  padding: 3px 8px;
  border-radius: 6px;
  background: #fbbf24;
  color: #78350f;
  display: flex;
  align-items: center;
  gap: 4px;
  letter-spacing: 0.04em;
  box-shadow: 0 1px 2px rgba(0, 0, 0, 0.1);
}

.vx-card-badge-passage {
  font-size: 12px;
  font-weight: 600;
  padding: 3px 10px;
  border-radius: 6px;
  background: rgba(0, 0, 0, 0.25);
  color: #ffffff;
  backdrop-filter: blur(4px);
  letter-spacing: 0.02em;
}

/* Center Graphic Shape */
.vx-card-graphic-center {
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  margin: auto;
  text-align: center;
  gap: 8px;
  z-index: 2;
}

.vx-card-center-icon {
  font-size: 34px;
  line-height: 1;
  opacity: 0.95;
  filter: drop-shadow(0 2px 4px rgba(0, 0, 0, 0.15));
}

.vx-card-volume-label {
  font-size: 14px;
  font-weight: 600;
  color: rgba(255, 255, 255, 0.95);
  letter-spacing: 0.02em;
  text-shadow: 0 1px 2px rgba(0, 0, 0, 0.2);
}

/* Card Bottom Content */
.vx-card-body {
  padding: 18px 20px 20px;
  display: flex;
  flex-direction: column;
  flex: 1;
}

.vx-card-title {
  font-size: 15px;
  font-weight: 700;
  color: var(--vx-cat-text);
  line-height: 1.35;
  margin: 0 0 6px;
}

.vx-card-sub-pack {
  font-size: 12px;
  color: var(--vx-cat-text-muted);
  font-weight: 500;
  margin-bottom: 12px;
  display: flex;
  align-items: center;
  gap: 6px;
}

/* Question Type Badges */
.vx-card-qtypes {
  display: flex;
  flex-wrap: wrap;
  gap: 6px;
  margin-bottom: 18px;
}

.vx-qtype-chip {
  font-size: 11.5px;
  font-weight: 500;
  padding: 3px 8px;
  border-radius: 6px;
  background: #f1f5f9;
  color: #475569;
  border: 1px solid var(--vx-cat-border);
}

.vx-qtype-more {
  font-size: 11.5px;
  font-weight: 600;
  padding: 3px 8px;
  border-radius: 6px;
  background: #f8fafc;
  color: var(--vx-cat-text-muted);
}

/* Card CTA Buttons */
.vx-card-actions {
  margin-top: auto;
  display: flex;
  gap: 8px;
  width: 100%;
}

.vx-card-cta-btn {
  width: 100%;
  height: 42px;
  border-radius: 8px;
  font-size: 14px;
  font-weight: 700;
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 6px;
  cursor: pointer;
  text-decoration: none;
  border: none;
  transition: transform 0.15s, opacity 0.15s, box-shadow 0.15s;
}

.vx-card-cta-btn.primary {
  background: linear-gradient(135deg, var(--vx-cat-cta-start) 0%, var(--vx-cat-cta-end) 100%);
  color: #ffffff;
  box-shadow: 0 2px 6px rgba(244, 63, 94, 0.25);
}

.vx-card-cta-btn.primary:hover {
  opacity: 0.95;
  transform: translateY(-1px);
  box-shadow: 0 4px 10px rgba(244, 63, 94, 0.35);
}

.vx-card-cta-btn.review {
  background: #f1f5f9;
  color: var(--vx-cat-text);
  border: 1px solid #cbd5e1;
}

.vx-card-cta-btn.review:hover {
  background: #e2e8f0;
}

.vx-card-cta-btn.unlock {
  background: linear-gradient(135deg, #5b8de6 0%, #245bc7 100%);
  color: #ffffff;
  box-shadow: 0 2px 6px rgba(36,91,199, 0.25);
}

.vx-card-cta-btn.unlock:hover {
  opacity: 0.95;
  transform: translateY(-1px);
}

/* 7. Loading and Empty States */
.vx-loading-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 24px;
}

.vx-skeleton-card {
  height: 320px;
  background: #ffffff;
  border-radius: 14px;
  border: 1px solid var(--vx-cat-border);
  position: relative;
  overflow: hidden;
}

.vx-skeleton-card::after {
  content: '';
  position: absolute;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  background: linear-gradient(90deg, transparent, rgba(255, 255, 255, 0.4), transparent);
  animation: vxSkeletonShimmer 1.5s infinite;
}

@keyframes vxSkeletonShimmer {
  0% { transform: translateX(-100%); }
  100% { transform: translateX(100%); }
}

.vx-catalog-empty {
  text-align: center;
  padding: 60px 20px;
  background: var(--vx-cat-surface);
  border-radius: 14px;
  border: 1px solid var(--vx-cat-border);
  grid-column: 1 / -1;
}

.vx-catalog-empty-icon {
  font-size: 48px;
  color: var(--vx-cat-text-light);
  margin-bottom: 12px;
}

.vx-catalog-empty h3 {
  font-size: 18px;
  font-weight: 700;
  color: var(--vx-cat-text);
  margin: 0 0 6px;
}

.vx-catalog-empty p {
  font-size: 14px;
  color: var(--vx-cat-text-muted);
  margin: 0 0 16px;
}

/* 8. Mobile Responsiveness (< 1024px) */
@media (max-width: 1024px) {
  .vx-catalog-sidebar {
    position: fixed;
    top: 0;
    left: -280px;
    height: 100vh;
    transition: left 0.25s cubic-bezier(0.16, 1, 0.3, 1);
    box-shadow: 4px 0 16px rgba(0, 0, 0, 0.1);
  }

  .vx-catalog-sidebar.open {
    left: 0;
  }

  .vx-sidebar-backdrop {
    display: none;
    position: fixed;
    inset: 0;
    background: rgba(0, 0, 0, 0.4);
    z-index: 35;
  }

  .vx-sidebar-backdrop.active {
    display: block;
  }

  .vx-catalog-mobile-bar {
    display: flex;
  }

  .vx-catalog-main {
    padding: 20px 20px 60px;
  }
}