/* ===========================================================
   COURSES LISTING & COURSE DETAIL
=========================================================== */

.course-filter-bar {
  display: flex; gap: 10px; margin-bottom: 34px; flex-wrap: wrap;
}
.filter-chip {
  padding: 9px 18px; border-radius: 100px; border: 1.5px solid var(--border);
  background: var(--white); font-size: 13.5px; font-weight: 600; color: var(--text-muted);
  transition: all 0.15s ease;
}
.filter-chip.active, .filter-chip:hover { border-color: var(--navy-800); color: var(--navy-800); background: var(--white); }

.course-grid { display: grid; grid-template-columns: repeat(3, 1fr); gap: 24px; }
.course-card { overflow: hidden; }
.course-card-thumb { position: relative; aspect-ratio: 16/9; overflow: hidden; }
.course-card-thumb img { width: 100%; height: 100%; object-fit: cover; }
.course-card-body { padding: 22px; }
.course-card-body h3 { font-size: 17px; margin: 10px 0 8px; }
.course-card-body p { font-size: 13.5px; color: var(--text-muted); margin-bottom: 14px; }
.course-meta { display: flex; align-items: center; gap: 14px; font-size: 12.5px; color: var(--text-muted); margin-bottom: 14px; }
.course-meta span { display: flex; align-items: center; gap: 4px; }

#coursesEmptyState, #coursesLoading { text-align: center; padding: 60px 0; color: var(--text-muted); grid-column: 1 / -1; }

/* Course detail page */
.course-detail-hero {
  background: linear-gradient(160deg, var(--navy-900) 0%, var(--navy-700) 100%);
  padding: 50px 0 70px; color: white;
}
.course-detail-hero .container { display: grid; grid-template-columns: 1.3fr 1fr; gap: 50px; align-items: start; }
.course-detail-hero h1 { color: white; font-size: clamp(26px, 4vw, 36px); margin: 14px 0; }
.course-detail-hero p.desc { color: rgba(255,255,255,0.72); font-size: 15.5px; margin-bottom: 20px; }
.course-detail-meta { display: flex; gap: 20px; flex-wrap: wrap; font-size: 13.5px; color: rgba(255,255,255,0.75); margin-bottom: 20px; }

.buy-card {
  background: var(--white); border-radius: var(--radius-lg); padding: 26px;
  box-shadow: var(--shadow-lg); color: var(--text-main); position: sticky; top: 100px;
}
.buy-card img { border-radius: var(--radius-sm); margin-bottom: 18px; aspect-ratio: 16/9; object-fit: cover; }
.buy-price { display: flex; align-items: baseline; gap: 10px; margin-bottom: 4px; }
.buy-price .now { font-family: var(--font-display); font-weight: 800; font-size: 28px; }
.buy-price .old { text-decoration: line-through; color: var(--text-muted); }
.buy-price .off { color: var(--success); font-size: 13px; font-weight: 700; }
.buy-card p.note { font-size: 12.5px; color: var(--text-muted); margin: 14px 0; text-align: center; }
.buy-includes { margin-top: 18px; display: flex; flex-direction: column; gap: 10px; }
.buy-includes li { font-size: 13.5px; display: flex; gap: 8px; align-items: flex-start; }
.buy-includes li::before { content: "✓"; color: var(--teal-dark); font-weight: 800; }

.curriculum-module { border: 1px solid var(--border); border-radius: var(--radius-md); margin-bottom: 14px; overflow: hidden; }
.curriculum-module-head {
  padding: 18px 22px; display: flex; justify-content: space-between; align-items: center;
  cursor: pointer; background: var(--white);
}
.curriculum-module-head h4 { font-size: 15.5px; }
.curriculum-module-head span { font-size: 13px; color: var(--text-muted); }
.curriculum-lessons { display: none; border-top: 1px solid var(--border); }
.curriculum-lessons.open { display: block; }
.curriculum-lesson {
  padding: 14px 22px; display: flex; justify-content: space-between; align-items: center;
  font-size: 14px; border-bottom: 1px solid var(--border);
}
.curriculum-lesson:last-child { border-bottom: none; }
.curriculum-lesson .left { display: flex; align-items: center; gap: 10px; color: var(--text-main); }

@media (max-width: 1024px) { .course-grid { grid-template-columns: repeat(2, 1fr); } }
@media (max-width: 900px) {
  .course-detail-hero .container { grid-template-columns: 1fr; }
  .buy-card { position: static; }
}
@media (max-width: 640px) { .course-grid { grid-template-columns: 1fr; } }