/* ═══════════════════════════════════════════════════
   COURSE DETAIL PAGE — CSS
   Professional product detail page styling
   ═══════════════════════════════════════════════════ */

/* ── Breadcrumb ── */
.breadcrumb {
  display: flex;
  align-items: center;
  gap: 8px;
  padding: 16px 0;
  font-size: 0.85rem;
  color: var(--text-muted);
}
.breadcrumb a {
  color: var(--text-muted);
  text-decoration: none;
  transition: color 0.2s;
}
.breadcrumb a:hover { color: var(--accent-gold); }
.breadcrumb__sep { opacity: 0.4; }
.breadcrumb__current { color: var(--text-secondary); }

/* ── Hero Section ── */
.course-hero {
  display: grid;
  grid-template-columns: 1fr 380px;
  gap: 48px;
  padding: 32px 0 48px;
  align-items: start;
}

.course-hero__main { display: flex; flex-direction: column; gap: 20px; }

.course-hero__badges { display: flex; gap: 8px; flex-wrap: wrap; }

.course-hero__badge {
  display: inline-flex;
  align-items: center;
  gap: 4px;
  padding: 4px 12px;
  border-radius: 20px;
  font-size: 0.75rem;
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 0.5px;
}
.course-hero__badge--category {
  background: rgba(212, 175, 55, 0.15);
  color: var(--accent-gold);
  border: 1px solid rgba(212, 175, 55, 0.3);
}
.course-hero__badge--tag {
  background: rgba(239, 68, 68, 0.15);
  color: #ef4444;
  border: 1px solid rgba(239, 68, 68, 0.3);
}

.course-hero__title {
  font-family: var(--font-display);
  font-size: clamp(1.8rem, 4vw, 2.8rem);
  font-weight: 700;
  line-height: 1.2;
  color: var(--text-primary);
}

.course-hero__desc {
  font-size: 1.05rem;
  color: var(--text-secondary);
  line-height: 1.7;
}

.course-hero__meta {
  display: flex;
  flex-wrap: wrap;
  gap: 20px;
  padding: 16px 0;
  border-top: 1px solid rgba(255,255,255,0.06);
  border-bottom: 1px solid rgba(255,255,255,0.06);
}

.course-meta-item {
  display: flex;
  align-items: center;
  gap: 8px;
  font-size: 0.85rem;
  color: var(--text-muted);
}
.course-meta-item__icon {
  font-size: 1.1rem;
  opacity: 0.7;
}
.course-meta-item__value {
  color: var(--text-secondary);
  font-weight: 500;
}

/* ── Purchase Card (Sticky Sidebar) ── */
.purchase-card {
  position: sticky;
  top: 100px;
  background: linear-gradient(135deg, rgba(20,20,30,0.95), rgba(15,15,25,0.98));
  border: 1px solid rgba(255,255,255,0.08);
  border-radius: 16px;
  padding: 28px;
  backdrop-filter: blur(20px);
  box-shadow: 0 20px 60px rgba(0,0,0,0.4);
}

.purchase-card__image {
  width: 100%;
  aspect-ratio: 16/9;
  border-radius: 12px;
  overflow: hidden;
  background: linear-gradient(135deg, #0a0a1a, #1a0a2e);
  display: flex;
  align-items: center;
  justify-content: center;
  margin-bottom: 20px;
}
.purchase-card__image img {
  width: 100%;
  height: 100%;
  object-fit: cover;
}
.purchase-card__image .purchase-card__emoji {
  font-size: 4rem;
}

.purchase-card__price {
  display: flex;
  align-items: baseline;
  gap: 12px;
  margin-bottom: 6px;
}
.purchase-card__price-current {
  font-size: 2.2rem;
  font-weight: 700;
  color: var(--text-primary);
}
.purchase-card__price-original {
  font-size: 1.1rem;
  color: var(--text-muted);
  text-decoration: line-through;
}
.purchase-card__price-free {
  font-size: 2.2rem;
  font-weight: 700;
  color: #22c55e;
}

.purchase-card__discount {
  display: inline-block;
  background: rgba(239, 68, 68, 0.15);
  color: #ef4444;
  font-size: 0.8rem;
  font-weight: 600;
  padding: 3px 10px;
  border-radius: 6px;
  margin-bottom: 20px;
}

.purchase-card__buy {
  display: block;
  width: 100%;
  padding: 14px;
  border: none;
  border-radius: 10px;
  font-size: 1rem;
  font-weight: 600;
  cursor: pointer;
  text-align: center;
  text-decoration: none;
  transition: all 0.3s ease;
  margin-bottom: 12px;
}
.purchase-card__buy--primary {
  background: linear-gradient(135deg, var(--accent-gold), #b8962e);
  color: #000;
}
.purchase-card__buy--primary:hover {
  transform: translateY(-2px);
  box-shadow: 0 8px 30px rgba(212,175,55,0.3);
}
.purchase-card__buy--free {
  background: linear-gradient(135deg, #22c55e, #16a34a);
  color: #fff;
}

.purchase-card__features {
  list-style: none;
  padding: 0;
  margin: 20px 0 0;
  display: flex;
  flex-direction: column;
  gap: 10px;
}
.purchase-card__features li {
  display: flex;
  align-items: center;
  gap: 8px;
  font-size: 0.85rem;
  color: var(--text-secondary);
}
.purchase-card__features li::before {
  content: '✓';
  color: #22c55e;
  font-weight: 700;
  flex-shrink: 0;
}

.purchase-card__guarantee {
  display: flex;
  align-items: center;
  gap: 8px;
  padding: 12px;
  margin-top: 16px;
  background: rgba(212,175,55,0.06);
  border: 1px solid rgba(212,175,55,0.15);
  border-radius: 8px;
  font-size: 0.8rem;
  color: var(--text-muted);
}
.purchase-card__guarantee-icon { font-size: 1.2rem; flex-shrink: 0; }

/* ── Navigation Tabs ── */
.course-nav {
  display: flex;
  gap: 4px;
  padding: 4px;
  background: rgba(255,255,255,0.03);
  border: 1px solid rgba(255,255,255,0.06);
  border-radius: 12px;
  margin-bottom: 40px;
  overflow-x: auto;
  -webkit-overflow-scrolling: touch;
}
.course-nav__tab {
  padding: 10px 20px;
  border-radius: 8px;
  font-size: 0.85rem;
  font-weight: 500;
  color: var(--text-muted);
  cursor: pointer;
  border: none;
  background: transparent;
  white-space: nowrap;
  transition: all 0.2s ease;
}
.course-nav__tab:hover { color: var(--text-secondary); background: rgba(255,255,255,0.04); }
.course-nav__tab.is-active {
  color: var(--accent-gold);
  background: rgba(212,175,55,0.1);
  border: 1px solid rgba(212,175,55,0.2);
}

/* ── Content Sections ── */
.course-content { display: grid; grid-template-columns: 1fr 380px; gap: 48px; padding-bottom: 80px; }
.course-content__main { min-width: 0; }

.course-section {
  margin-bottom: 48px;
  scroll-margin-top: 80px;
}
.course-section__title {
  font-family: var(--font-display);
  font-size: 1.5rem;
  font-weight: 700;
  color: var(--text-primary);
  margin-bottom: 20px;
  display: flex;
  align-items: center;
  gap: 10px;
}
.course-section__title-icon { font-size: 1.3rem; }

/* ── Overview ── */
.course-overview {
  font-size: 1rem;
  color: var(--text-secondary);
  line-height: 1.8;
  white-space: pre-line;
}

/* ── Gallery ── */
.course-gallery {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(280px, 1fr));
  gap: 16px;
}
.course-gallery__item {
  border-radius: 12px;
  overflow: hidden;
  aspect-ratio: 16/9;
  cursor: pointer;
  position: relative;
  border: 1px solid rgba(255,255,255,0.06);
  transition: transform 0.3s ease, box-shadow 0.3s ease;
}
.course-gallery__item:hover {
  transform: scale(1.02);
  box-shadow: 0 8px 30px rgba(0,0,0,0.4);
}
.course-gallery__item img {
  width: 100%;
  height: 100%;
  object-fit: cover;
}
.course-gallery__empty {
  grid-column: 1 / -1;
  padding: 40px;
  text-align: center;
  color: var(--text-muted);
  font-size: 0.9rem;
  background: rgba(255,255,255,0.02);
  border: 1px dashed rgba(255,255,255,0.1);
  border-radius: 12px;
}

/* ── Curriculum ── */
.course-curriculum {
  list-style: none;
  padding: 0;
  display: flex;
  flex-direction: column;
  gap: 0;
  counter-reset: curriculum;
}
.course-curriculum__item {
  counter-increment: curriculum;
  display: flex;
  align-items: flex-start;
  gap: 14px;
  padding: 16px 18px;
  border: 1px solid rgba(255,255,255,0.05);
  border-bottom: none;
  background: rgba(255,255,255,0.02);
  transition: background 0.2s;
}
.course-curriculum__item:first-child { border-radius: 12px 12px 0 0; }
.course-curriculum__item:last-child { border-radius: 0 0 12px 12px; border-bottom: 1px solid rgba(255,255,255,0.05); }
.course-curriculum__item:only-child { border-radius: 12px; border-bottom: 1px solid rgba(255,255,255,0.05); }
.course-curriculum__item:hover { background: rgba(255,255,255,0.04); }

.course-curriculum__num {
  width: 28px;
  height: 28px;
  min-width: 28px;
  border-radius: 8px;
  background: rgba(212,175,55,0.12);
  color: var(--accent-gold);
  font-size: 0.75rem;
  font-weight: 700;
  display: flex;
  align-items: center;
  justify-content: center;
}
.course-curriculum__num::before { content: counter(curriculum); }

.course-curriculum__text {
  font-size: 0.92rem;
  color: var(--text-secondary);
  line-height: 1.5;
  padding-top: 3px;
}

/* ── Method ── */
.course-method {
  display: flex;
  flex-direction: column;
  gap: 16px;
}
.course-method__step {
  display: flex;
  gap: 14px;
  padding: 18px;
  background: rgba(255,255,255,0.02);
  border: 1px solid rgba(255,255,255,0.06);
  border-radius: 12px;
  transition: all 0.2s;
}
.course-method__step:hover {
  background: rgba(212,175,55,0.04);
  border-color: rgba(212,175,55,0.15);
}
.course-method__step-num {
  width: 32px;
  height: 32px;
  min-width: 32px;
  border-radius: 50%;
  background: linear-gradient(135deg, var(--accent-gold), #b8962e);
  color: #000;
  font-size: 0.8rem;
  font-weight: 700;
  display: flex;
  align-items: center;
  justify-content: center;
}
.course-method__step-text {
  font-size: 0.92rem;
  color: var(--text-secondary);
  line-height: 1.6;
  padding-top: 5px;
}

/* ── Instructor ── */
.instructor-card {
  display: flex;
  gap: 20px;
  padding: 24px;
  background: rgba(255,255,255,0.02);
  border: 1px solid rgba(255,255,255,0.06);
  border-radius: 16px;
}
.instructor-card__avatar {
  width: 72px;
  height: 72px;
  min-width: 72px;
  border-radius: 50%;
  background: linear-gradient(135deg, var(--accent-gold), #b8962e);
  color: #000;
  font-size: 1.8rem;
  font-weight: 700;
  display: flex;
  align-items: center;
  justify-content: center;
}
.instructor-card__name {
  font-size: 1.1rem;
  font-weight: 600;
  color: var(--text-primary);
  margin-bottom: 4px;
}
.instructor-card__role {
  font-size: 0.85rem;
  color: var(--accent-gold);
  margin-bottom: 8px;
}
.instructor-card__bio {
  font-size: 0.88rem;
  color: var(--text-muted);
  line-height: 1.6;
}

/* ── Related Products ── */
.related-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(260px, 1fr));
  gap: 20px;
}

/* ── Share Button ── */
.share-btn {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  padding: 8px 16px;
  border: 1px solid rgba(255,255,255,0.1);
  border-radius: 8px;
  background: transparent;
  color: var(--text-muted);
  font-size: 0.8rem;
  cursor: pointer;
  transition: all 0.2s;
}
.share-btn:hover { border-color: var(--accent-gold); color: var(--accent-gold); }

/* ── Lightbox ── */
.lightbox {
  position: fixed;
  inset: 0;
  z-index: 9999;
  background: rgba(0,0,0,0.92);
  display: none;
  align-items: center;
  justify-content: center;
  cursor: pointer;
}
.lightbox.is-open { display: flex; }
.lightbox img {
  max-width: 90vw;
  max-height: 90vh;
  border-radius: 8px;
  box-shadow: 0 20px 60px rgba(0,0,0,0.5);
}

/* ── Responsive ── */
@media (max-width: 900px) {
  .course-hero { grid-template-columns: 1fr; gap: 28px; }
  .course-content { grid-template-columns: 1fr; }

  /* Purchase card flows naturally in the page (NOT a fixed popup bar).
     Viewer reads the course details first, then reaches the buy card. */
  .purchase-card {
    position: static;
    border-radius: 16px;
    padding: 22px;
  }
  .purchase-card__image { display: none; }
  .course-content__sidebar { display: none; }
}

@media (max-width: 600px) {
  .course-gallery { grid-template-columns: 1fr; }
  .course-hero__meta { gap: 12px; }
  .course-nav { gap: 2px; }
  .course-nav__tab { padding: 8px 14px; font-size: 0.8rem; }
}