/* courses.css */

.page-header {
  text-align: center;
  max-width: 800px;
  margin: 0 auto;
}

.page-header h1 {
  font-size: 3rem;
  margin-bottom: var(--spacing-sm);
}

.page-header p {
  color: var(--text-secondary);
  font-size: 1.2rem;
  margin-bottom: var(--spacing-lg);
}

.filters {
  display: flex;
  justify-content: center;
  gap: var(--spacing-md);
  margin-top: var(--spacing-lg);
  flex-wrap: wrap;
}

.filter-btn {
  background: var(--bg-surface);
  border: 1px solid var(--border-color);
  color: var(--text-secondary);
  padding: 0.5rem 1.2rem;
  border-radius: 20px;
  cursor: pointer;
  transition: all var(--transition-fast);
  font-family: var(--font-family);
  font-weight: 500;
}

.filter-btn:hover, .filter-btn.active {
  background: var(--primary-accent);
  color: white;
  border-color: var(--primary-accent);
  box-shadow: 0 4px 10px rgba(88, 166, 255, 0.3);
}

/* Playback Layout */
.playback-body {
  background-color: #000;
  height: 100vh;
  overflow: hidden;
  display: flex;
  flex-direction: column;
}

.back-btn {
  color: var(--text-secondary);
  font-weight: 500;
}

.back-btn:hover {
  color: var(--primary-accent);
}

.divider {
  width: 1px;
  height: 20px;
  background-color: var(--border-color);
}

.course-title-nav {
  font-weight: 600;
  color: white;
}

.playback-layout {
  display: flex;
  flex: 1;
  overflow: hidden;
  margin-top: 70px; /* Account for navbar */
}

.video-section {
  flex: 1;
  display: flex;
  flex-direction: column;
  overflow-y: auto;
  padding: var(--spacing-md);
  background-color: #0b0f15;
}

.video-wrapper {
  aspect-ratio: 16/9;
  width: 100%;
  max-width: 1200px;
  margin: 0 auto;
  background-color: #000;
  border-radius: 12px;
  overflow: hidden;
  position: relative;
  box-shadow: 0 10px 30px rgba(0,0,0,0.5);
}

.video-player {
  width: 100%;
  height: 100%;
  position: relative;
  background: radial-gradient(circle at center, #1a202c 0%, #000 100%);
}

.placeholder-poster {
  position: absolute;
  top: 0; left: 0; right: 0; bottom: 0;
  display: flex;
  flex-direction: column;
  justify-content: center;
  align-items: center;
  color: white;
}

.play-button-large {
  width: 80px;
  height: 80px;
  background: var(--primary-accent);
  border-radius: 50%;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 2rem;
  cursor: pointer;
  margin-bottom: var(--spacing-md);
  box-shadow: 0 0 30px rgba(88, 166, 255, 0.4);
  transition: transform var(--transition-fast);
}

.play-button-large:hover {
  transform: scale(1.1);
}

.video-controls {
  position: absolute;
  bottom: 0;
  left: 0;
  right: 0;
  padding: 1rem;
  background: linear-gradient(to top, rgba(0,0,0,0.8), transparent);
  display: flex;
  align-items: center;
  gap: 1rem;
}

.control-icon {
  color: white;
  cursor: pointer;
}

.progress-bar {
  flex: 1;
  height: 4px;
  background: rgba(255,255,255,0.3);
  border-radius: 2px;
  cursor: pointer;
}

.progress {
  height: 100%;
  background: var(--primary-accent);
  border-radius: 2px;
  position: relative;
}

.progress::after {
  content: '';
  position: absolute;
  right: -5px;
  top: -4px;
  width: 12px;
  height: 12px;
  background: white;
  border-radius: 50%;
}

.time {
  color: white;
  font-size: 0.85rem;
  font-family: monospace;
}

.course-details {
  max-width: 1200px;
  margin: var(--spacing-lg) auto;
  width: 100%;
}

.details-header {
  display: flex;
  justify-content: space-between;
  align-items: flex-start;
  margin-bottom: var(--spacing-md);
}

.instructor {
  display: flex;
  align-items: center;
  gap: var(--spacing-sm);
  margin-bottom: var(--spacing-md);
  padding: var(--spacing-sm) 0;
  border-top: 1px solid var(--border-color);
  border-bottom: 1px solid var(--border-color);
}

.avatar {
  width: 40px;
  height: 40px;
  border-radius: 50%;
  background: linear-gradient(135deg, #4fd1c5, #319795);
}

.text-sm {
  font-size: 0.85rem;
  color: var(--text-secondary);
}

.description p {
  color: var(--text-secondary);
  line-height: 1.8;
}

/* Sidebar */
.syllabus-sidebar {
  width: 380px;
  border-left: 1px solid var(--border-color);
  background-color: var(--bg-surface);
  display: flex;
  flex-direction: column;
  padding: var(--spacing-md);
  overflow-y: auto;
}

.syllabus-sidebar h3 {
  margin-bottom: var(--spacing-sm);
}

.progress-text {
  display: flex;
  justify-content: space-between;
  font-size: 0.85rem;
  color: var(--text-secondary);
  margin-bottom: var(--spacing-xs);
}

.progress-bar-bg {
  width: 100%;
  height: 6px;
  background: var(--border-color);
  border-radius: 3px;
  overflow: hidden;
}

.progress-bar-fill {
  height: 100%;
  background: var(--primary-accent);
}

.lesson-list {
  display: flex;
  flex-direction: column;
  gap: var(--spacing-xs);
}

.lesson-item {
  display: flex;
  align-items: center;
  gap: var(--spacing-sm);
  padding: var(--spacing-sm);
  border-radius: 8px;
  cursor: pointer;
  transition: background var(--transition-fast);
}

.lesson-item:hover {
  background: rgba(255, 255, 255, 0.05);
}

.lesson-item.active {
  background: rgba(88, 166, 255, 0.1);
  border: 1px solid rgba(88, 166, 255, 0.2);
}

.lesson-item.playing h4 {
  color: var(--primary-accent);
}

.lesson-status {
  width: 24px;
  height: 24px;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 0.85rem;
  border-radius: 50%;
  background: var(--border-color);
}

.lesson-status.completed {
  background: #48bb78;
  color: white;
}

.lesson-item.playing .lesson-status {
  background: var(--primary-accent);
  color: white;
}

.lesson-info h4 {
  font-size: 0.95rem;
  margin-bottom: 2px;
}

.lesson-info span {
  font-size: 0.75rem;
  color: var(--text-secondary);
}

/* Auth Paywall Overlay */
.auth-overlay {
  position: absolute;
  top: 0; left: 0; right: 0; bottom: 0;
  background: rgba(13, 17, 23, 0.85);
  backdrop-filter: blur(8px);
  display: flex;
  align-items: center;
  justify-content: center;
  z-index: 20;
}

.auth-content {
  text-align: center;
  padding: var(--spacing-xl);
  border-radius: 16px;
  max-width: 500px;
  background: var(--bg-surface);
  border: 1px solid var(--border-color);
  box-shadow: 0 10px 40px rgba(0,0,0,0.5);
}

.auth-content h3 {
  font-size: 2rem;
  margin-bottom: var(--spacing-sm);
  color: var(--primary-accent);
}

.auth-content p {
  color: var(--text-secondary);
  font-size: 1.1rem;
  margin-bottom: var(--spacing-lg);
}

.auth-actions {
  display: flex;
  flex-direction: column;
  gap: var(--spacing-md);
}

@media screen and (min-width: 480px) {
  .auth-actions {
    flex-direction: row;
    justify-content: center;
  }
}