/* =============================================================================
   PAGE-SPECIFIC: COURSES CATALOG
============================================================================= */

/* Promo Banner */
.promo-banner-section {
  padding: clamp(36px, 5vw, 56px) 0 var(--space-6);
}
.promo-banner-link {
  display: block;
  border-radius: var(--radius-lg);
  overflow: hidden;
  box-shadow: 0 6px 20px var(--shadow-dark-banner);
  transition: transform var(--transition-base), box-shadow var(--transition-base);
}
.promo-banner-link:hover {
  transform: translateY(-3px);
  box-shadow: 0 12px 28px var(--shadow-dark-banner-hover);
}
.promo-banner-img {
  width: 100%;
  height: auto;
  display: block;
  object-fit: cover;
}

/* Intro & Heading */
.courses-intro {
  margin-top: var(--space-4);
  margin-bottom: var(--space-7);
}
.section-tag-red {
  color: var(--primary);
  font-size: var(--font-size-4xl);
  font-weight: 700;
  letter-spacing: -0.5px;
  margin-bottom: var(--space-3);
}
.section-description {
  color: var(--color-text-tertiary);
  font-size: var(--font-size-base);
  line-height: 1.7;
  max-width: 980px;
}

/* Filter Tabs */
.category-tabs-container {
  margin: var(--space-7) 0 var(--space-8);
}
.category-tabs-grid {
  display: flex;
  flex-wrap: wrap;
  justify-content: center;
  gap: var(--space-3);
}
.category-tab-btn {
  display: inline-flex;
  align-items: center;
  gap: 10px;
  background: var(--color-surface-card);
  border: 1px solid var(--color-border-subtle);
  border-radius: var(--radius-md);
  padding: 12px 18px;
  font-size: var(--font-size-sm);
  font-weight: var(--font-weight-semibold);
  color: var(--color-text-primary);
  box-shadow: var(--shadow-xs);
  transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
  user-select: none;
  cursor: pointer;
  text-decoration: none;
  position: relative;
  overflow: hidden;
}
.category-tab-btn::before {
  content: '';
  position: absolute;
  top: 0;
  left: -100%;
  width: 100%;
  height: 100%;
  background: linear-gradient(90deg, transparent, rgba(234, 88, 12, 0.1), transparent);
  transition: left 0.5s ease;
}
.category-tab-btn:hover::before {
  left: 100%;
}
.category-tab-btn:hover {
  border-color: var(--primary);
  color: var(--primary);
  transform: translateY(-2px);
  box-shadow: 0 4px 12px var(--color-primary-shadow);
}
.category-tab-btn.active {
  background: linear-gradient(135deg, var(--color-primary-light) 0%, var(--color-info-light) 100%);
  border-color: var(--primary);
  color: var(--primary);
  box-shadow: 0 4px 12px var(--shadow-accent);
  transform: translateY(-1px);
}
.category-icon-wrapper {
  width: 24px;
  height: 24px;
  display: flex;
  align-items: center;
  justify-content: center;
  color: var(--primary);
  transition: transform 0.3s ease;
}
.category-tab-btn:hover .category-icon-wrapper {
  transform: scale(1.1);
}
.category-tab-btn.active .category-icon-wrapper,
.category-tab-btn:hover .category-icon-wrapper {
  color: var(--primary);
}

/* Smooth page transitions */
.category-group-block {
  animation: fadeInUp 0.5s ease-out;
}

@keyframes fadeInUp {
  from {
    opacity: 0;
    transform: translateY(20px);
  }
  to {
    opacity: 1;
    transform: translateY(0);
  }
}

/* Department Section Groups */
.category-group-block {
  margin-bottom: var(--space-10);
  scroll-margin-top: 24px;
}
.category-group-title {
  font-size: var(--font-size-xl);
  font-weight: 700;
  color: var(--primary);
  margin-bottom: var(--space-5);
  position: relative;
  display: inline-flex;
  align-items: center;
  gap: 10px;
}
.category-group-title::after {
  content: '';
  position: absolute;
  bottom: -6px;
  left: 0;
  width: 44px;
  height: 3px;
  background: var(--primary);
  border-radius: 2px;
}

/* Courses Grid */
.courses-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 28px;
}

/* =============================================================================
   COURSE CARD (Synchronized 1:1 with Homepage Popular Courses UI & UX)
============================================================================= */
.courses-grid .course-card {
  background: var(--color-surface-card);
  border: 1px solid var(--color-border-frost);
  border-radius: var(--radius-lg, 12px);
  overflow: hidden;
  padding: 0;
  display: flex;
  flex-direction: column;
  box-shadow: 0 4px 20px var(--shadow-dark-subtle);
  transition: transform 300ms cubic-bezier(0.4, 0, 0.2, 1), 
              box-shadow 300ms cubic-bezier(0.4, 0, 0.2, 1), 
              border-color 300ms ease;
  cursor: pointer;
  position: relative;
  min-width: 0;
  animation: fadeInScale 0.4s ease-out backwards;
}

/* Stagger animation for cards */
.courses-grid .course-card:nth-child(1) { animation-delay: 0.05s; }
.courses-grid .course-card:nth-child(2) { animation-delay: 0.1s; }
.courses-grid .course-card:nth-child(3) { animation-delay: 0.15s; }
.courses-grid .course-card:nth-child(4) { animation-delay: 0.2s; }
.courses-grid .course-card:nth-child(5) { animation-delay: 0.25s; }
.courses-grid .course-card:nth-child(6) { animation-delay: 0.3s; }

@keyframes fadeInScale {
  from {
    opacity: 0;
    transform: scale(0.95) translateY(10px);
  }
  to {
    opacity: 1;
    transform: scale(1) translateY(0);
  }
}

.courses-grid .course-card:hover {
  transform: translateY(-5px);
  box-shadow: 0 14px 32px var(--shadow-dark-medium-alt);
  border-color: var(--border-color);
}

/* Shimmer effect on hover */
.courses-grid .course-card::after {
  content: '';
  position: absolute;
  top: 0;
  left: -100%;
  width: 50%;
  height: 100%;
  background: linear-gradient(90deg, transparent, rgba(255, 255, 255, 0.3), transparent);
  transition: left 0.6s ease;
  pointer-events: none;
}

.courses-grid .course-card:hover::after {
  left: 100%;
}

/* Thumbnail Wrapper */
.courses-grid .card-thumb-wrapper {
  position: relative;
  width: 100%;
  aspect-ratio: 16 / 9.5;
  overflow: hidden;
}

.courses-grid .thumb-bg {
  width: 100%;
  height: 100%;
  object-fit: cover;
  display: block;
  transition: transform 450ms ease;
}

.courses-grid .course-card:hover .thumb-bg {
  transform: scale(1.04);
}

/* Card Body */
.courses-grid .card-body {
  padding: clamp(16px, 2.2vw, 22px);
  display: flex;
  flex-direction: column;
  flex-grow: 1;
}

/* Category Label */
.courses-grid .card-category-link {
  text-decoration: none;
  display: inline-block;
  align-self: flex-start;
}

.courses-grid .card-category {
  font-size: 13.5px;
  font-weight: 700;
  color: var(--primary);
  margin-bottom: 8px;
  letter-spacing: 0.1px;
  transition: color 200ms ease;
}

.courses-grid .card-category-link:hover .card-category {
  color: var(--color-primary-dark, #be123c);
}

/* Card Anchor Links for Crawlability */
.courses-grid .card-thumb-link {
  display: block;
  width: 100%;
  height: 100%;
  text-decoration: none;
}

/* Card Title */
.courses-grid .card-title {
  font-size: clamp(1.05rem, 1.2vw, 1.18rem);
  font-weight: 700;
  color: var(--color-text-primary, #1e293b);
  line-height: 1.4;
  margin-bottom: 16px;
  min-height: 48px;
  display: -webkit-box;
  -webkit-line-clamp: 2;
  -webkit-box-orient: vertical;
  overflow: hidden;
}

.courses-grid .card-title-link {
  color: inherit;
  text-decoration: none;
  transition: color 200ms ease;
}

.courses-grid .course-card:hover .card-title-link {
  color: var(--primary, #e11d48);
}

/* Card Footer Row */
.courses-grid .card-footer-row {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 12px;
  margin-top: auto;
  padding-top: 14px;
  border-top: 1px solid #f1f2f4;
  flex-wrap: wrap;
}

/* Course Fee */
.courses-grid .course-fee {
  font-size: 14.5px;
  font-weight: 700;
  color: var(--color-text-primary, #1e293b);
  white-space: nowrap;
}

/* View Details Outline Red Button */
.courses-grid .btn-view-details {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  padding: 7px 16px;
  border-radius: var(--radius-sm, 6px);
  border: 1.5px solid var(--primary);
  color: var(--primary);
  font-size: 12.5px;
  font-weight: 600;
  background-color: transparent;
  text-decoration: none;
  transition: all 200ms ease;
  white-space: nowrap;
  cursor: pointer;
}

.courses-grid .btn-view-details:hover {
  background-color: var(--primary);
  color: var(--text-inverse);
  box-shadow: 0 4px 12px var(--color-primary-shadow-md);
  transform: translateY(-1px);
}

/* Responsive Breakpoints */
@media (max-width: 992px) {
  .courses-grid {
    grid-template-columns: repeat(2, 1fr);
    gap: var(--space-5);
  }
}

@media (max-width: 640px) {
  .courses-grid {
    grid-template-columns: 1fr;
  }
}