/* ============================================================
   BrainHub — Courses (hub + player)
   ============================================================ */

/* ── Hub page ── */
.courses-hero { text-align: center; padding: 3rem 0 2.5rem; }
.courses-hero h1 {
  font-family: var(--font-display); font-size: clamp(2rem, 5vw, 3rem);
  font-weight: 800; color: var(--text-900); letter-spacing: -0.03em; margin-bottom: 0.5rem;
}
.courses-hero p { color: var(--text-500); font-size: 1.05rem; max-width: 560px; margin: 0 auto; }

.courses-tabs {
  display: flex; gap: 0.5rem; justify-content: center;
  margin: 2rem 0 2.5rem; flex-wrap: wrap;
}
.courses-tab {
  padding: 0.55rem 1.25rem; border-radius: 60px;
  border: 1.5px solid var(--border); background: var(--card);
  color: var(--text-700); font-size: 0.9rem; font-weight: 700;
  cursor: pointer; transition: var(--transition); font-family: inherit;
}
.courses-tab:hover { border-color: var(--primary); color: var(--primary); }
.courses-tab.active { background: var(--primary); border-color: var(--primary); color: #fff; }

.course-filters {
  display: flex; gap: 0.5rem; flex-wrap: wrap; justify-content: center; margin-bottom: 2rem;
}
.course-filter-pill {
  padding: 0.4rem 1rem; border-radius: 60px; border: 1.5px solid var(--border);
  background: var(--card); color: var(--text-700); font-size: 0.82rem; font-weight: 600;
  cursor: pointer; transition: var(--transition); font-family: inherit;
}
.course-filter-pill:hover { border-color: var(--primary); color: var(--primary); }
.course-filter-pill.active { background: var(--primary-light); border-color: var(--primary); color: var(--primary); }

.course-section-title {
  font-family: var(--font-display); font-size: 1.15rem; font-weight: 800;
  color: var(--text-900); margin: 2.5rem 0 1.25rem; display: flex; align-items: center; gap: 0.6rem;
}
.course-section-title .count { font-size: 0.8rem; font-weight: 600; color: var(--text-400); }

.course-grid {
  display: grid; grid-template-columns: repeat(auto-fill, minmax(270px, 1fr)); gap: 1.25rem;
}

.course-card {
  background: var(--card); border: 1px solid var(--border); border-radius: var(--radius-lg);
  padding: 1.5rem; text-decoration: none; color: inherit;
  display: flex; flex-direction: column; gap: 0.9rem;
  transition: var(--transition); opacity: 0; transform: translateY(10px);
  animation: courseCardIn 0.5s ease forwards;
}
.course-card:hover { transform: translateY(-5px); box-shadow: var(--shadow); border-color: var(--primary); }
@keyframes courseCardIn { to { opacity: 1; transform: translateY(0); } }

.course-icon {
  width: 48px; height: 48px; border-radius: 12px;
  display: flex; align-items: center; justify-content: center; font-size: 1.3rem; flex-shrink: 0;
}
.course-card h3 { font-family: var(--font-display); font-size: 1.05rem; font-weight: 700; color: var(--text-900); }
.course-card p { font-size: 0.85rem; color: var(--text-500); line-height: 1.5; flex: 1; }

.course-meta { display: flex; align-items: center; gap: 0.6rem; flex-wrap: wrap; font-size: 0.75rem; color: var(--text-400); }
.course-level-badge {
  padding: 0.15rem 0.6rem; border-radius: 60px; font-weight: 700; text-transform: capitalize;
  background: var(--bg-muted); color: var(--text-600, var(--text-700));
}
.course-level-badge.beginner { background: #f0fdf4; color: #15803d; }
.course-level-badge.intermediate { background: #fff7ed; color: #c2410c; }
.course-level-badge.advanced { background: #fef2f2; color: #dc2626; }

.course-progress-track { height: 6px; border-radius: 60px; background: var(--bg-muted); overflow: hidden; }
.course-progress-fill { height: 100%; background: var(--primary); border-radius: 60px; transition: width 0.4s ease; }
.course-progress-label { font-size: 0.72rem; color: var(--text-400); font-weight: 600; }

/* External / Coursera directory */
.external-card {
  background: var(--card); border: 1px solid var(--border); border-radius: var(--radius-lg);
  padding: 1.5rem; display: flex; flex-direction: column; gap: 0.75rem;
  text-decoration: none; color: inherit; transition: var(--transition);
  opacity: 0; transform: translateY(10px); animation: courseCardIn 0.5s ease forwards;
}
.external-card:hover { transform: translateY(-5px); box-shadow: var(--shadow); border-color: var(--primary); }
.provider-badge {
  display: inline-flex; align-items: center; gap: 0.35rem; width: fit-content;
  padding: 0.2rem 0.65rem; border-radius: 60px; font-size: 0.7rem; font-weight: 800;
  text-transform: uppercase; letter-spacing: 0.04em;
}
.provider-badge.coursera { background: #eef2ff; color: #2938e0; }
.provider-badge.edx      { background: #fef2f2; color: #b91c1c; }
.provider-badge.youtube  { background: #fef2f2; color: #dc2626; }
.provider-badge.other    { background: var(--bg-muted); color: var(--text-500); }
.external-card h3 { font-family: var(--font-display); font-size: 1rem; font-weight: 700; color: var(--text-900); }
.external-card p { font-size: 0.82rem; color: var(--text-500); line-height: 1.5; flex: 1; }
.external-card .go-link { font-size: 0.8rem; font-weight: 700; color: var(--primary); display: flex; align-items: center; gap: 0.35rem; }
.external-card:hover .go-link { gap: 0.55rem; }

.courses-empty { text-align: center; padding: 3rem 1rem; color: var(--text-500); }

/* ── Course player page ── */
.player-layout { display: grid; grid-template-columns: 300px 1fr; gap: 2.5rem; align-items: start; padding: 2rem 0 5rem; }
@media (max-width: 860px) { .player-layout { grid-template-columns: 1fr; } }

.player-sidebar { position: sticky; top: 90px; background: var(--card); border: 1px solid var(--border); border-radius: var(--radius-lg); padding: 1.25rem; }
@media (max-width: 860px) { .player-sidebar { position: static; } }

.player-course-title { font-family: var(--font-display); font-size: 1.05rem; font-weight: 800; color: var(--text-900); margin-bottom: 0.75rem; }
.player-progress-wrap { margin-bottom: 1.25rem; }
.player-progress-track { height: 8px; border-radius: 60px; background: var(--bg-muted); overflow: hidden; margin-bottom: 0.4rem; }
.player-progress-fill { height: 100%; background: linear-gradient(90deg, var(--primary), var(--accent, #06b6d4)); border-radius: 60px; transition: width 0.5s ease; }
.player-progress-text { font-size: 0.75rem; color: var(--text-500); font-weight: 600; }

.player-module { margin-bottom: 1rem; }
.player-module-title { font-size: 0.7rem; font-weight: 800; text-transform: uppercase; letter-spacing: 0.08em; color: var(--text-400); margin-bottom: 0.4rem; padding-left: 0.25rem; }
.player-lesson {
  display: flex; align-items: center; gap: 0.65rem; padding: 0.6rem 0.6rem;
  border-radius: 10px; cursor: pointer; font-size: 0.85rem; color: var(--text-700);
  transition: var(--transition); border: 1px solid transparent;
}
.player-lesson:hover { background: var(--bg-muted); }
.player-lesson.active { background: var(--primary-light); color: var(--primary); font-weight: 700; border-color: var(--primary); }
.player-lesson-check {
  width: 18px; height: 18px; border-radius: 50%; border: 2px solid var(--border);
  display: flex; align-items: center; justify-content: center; font-size: 0.6rem; flex-shrink: 0; transition: var(--transition);
}
.player-lesson.done .player-lesson-check { background: #22c55e; border-color: #22c55e; color: #fff; }

.player-main { background: var(--card); border: 1px solid var(--border); border-radius: var(--radius-lg); padding: 2rem; min-height: 400px; }
.player-lesson-title { font-family: var(--font-display); font-size: 1.5rem; font-weight: 800; color: var(--text-900); margin-bottom: 0.4rem; }
.player-lesson-duration { font-size: 0.8rem; color: var(--text-400); margin-bottom: 1.5rem; display: flex; align-items: center; gap: 0.4rem; }
.player-video-embed { position: relative; width: 100%; padding-top: 56.25%; margin-bottom: 1.5rem; border-radius: var(--radius-sm); overflow: hidden; background: var(--bg-muted); }
.player-video-embed iframe { position: absolute; inset: 0; width: 100%; height: 100%; border: 0; }
.player-lesson-body { font-size: 0.95rem; line-height: 1.75; color: var(--text-700); }
.player-lesson-body h1, .player-lesson-body h2, .player-lesson-body h3 { font-family: var(--font-display); color: var(--text-900); margin: 1.5rem 0 0.75rem; }
.player-lesson-body p { margin-bottom: 1rem; }
.player-lesson-body code { background: var(--bg-muted); padding: 0.1rem 0.4rem; border-radius: 4px; font-family: 'Courier New', monospace; font-size: 0.85em; }

.player-actions { display: flex; align-items: center; justify-content: space-between; margin-top: 2rem; padding-top: 1.5rem; border-top: 1px solid var(--border); flex-wrap: wrap; gap: 1rem; }
.player-nav-btns { display: flex; gap: 0.6rem; }

.cert-unlock-banner {
  display: flex; align-items: center; justify-content: space-between; gap: 1rem;
  background: linear-gradient(135deg, var(--primary-light), var(--card));
  border: 1.5px dashed var(--primary); border-radius: var(--radius-lg);
  padding: 1.25rem 1.5rem; margin-bottom: 2rem; flex-wrap: wrap;
  animation: certPulse 2.4s ease-in-out infinite;
}
@keyframes certPulse { 0%,100% { box-shadow: 0 0 0 0 rgba(37,99,235,0.15); } 50% { box-shadow: 0 0 0 8px rgba(37,99,235,0); } }
.cert-unlock-banner h4 { font-family: var(--font-display); font-size: 1rem; color: var(--text-900); margin-bottom: 0.2rem; }
.cert-unlock-banner p { font-size: 0.82rem; color: var(--text-500); }