/* Thematic Stylesheet: Editorial Warm */
:root {
  --bg-primary: #fcfbf7;
  --bg-secondary: #f3f0e6;
  --bg-card: #ffffff;
  --text-primary: #1c1917;
  --text-secondary: #44403c;
  --text-muted: #78716c;
  --accent: #b45309;
  --accent-hover: #92400e;
  --border-color: #e7e2d4;
  --badge-bg: #fef3c7;
  --badge-text: #92400e;
  --ad-bg: #f5f2e9;
}

* {
  box-sizing: border-box;
  margin: 0;
  padding: 0;
}

body {
  background-color: var(--bg-primary);
  color: var(--text-primary);
  font-family: 'Plus Jakarta Sans', system-ui, sans-serif;
  line-height: 1.6;
  -webkit-font-smoothing: antialiased;
}

h1, h2, h3, h4, h5, h6 {
  font-family: Georgia, 'Times New Roman', serif;
  color: var(--text-primary);
  line-height: 1.25;
}

a {
  color: inherit;
  text-decoration: none;
}

/* Layout container */
.container {
  max-width: 1280px;
  margin: 0 auto;
  padding: 0 1.5rem;
}

/* Header & Nav */
.site-header {
  border-bottom: 1px solid var(--border-color);
  background-color: var(--bg-secondary);
  position: sticky;
  top: 0;
  z-index: 50;
  backdrop-filter: blur(8px);
}

.nav-wrapper {
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: 4.25rem;
}

.brand-link {
  display: flex;
  align-items: center;
  gap: 0.75rem;
  font-weight: 700;
  font-size: 1.15rem;
}

.brand-icon {
  width: 2rem;
  height: 2rem;
  background-color: var(--accent);
  color: #ffffff;
  border-radius: 0.5rem;
  display: flex;
  align-items: center;
  justify-content: center;
}

.nav-breadcrumbs {
  display: flex;
  align-items: center;
  gap: 0.5rem;
  font-size: 0.875rem;
  color: var(--text-muted);
}

.nav-breadcrumbs a:hover {
  color: var(--text-primary);
}

/* Main Grid Layout for Video Page */
.video-layout {
  display: grid;
  grid-template-columns: 1fr;
  gap: 2rem;
  padding: 2rem 0 4rem 0;
}

@media (min-width: 1024px) {
  .video-layout {
    grid-template-columns: 1fr 380px;
    align-items: start;
  }
}

/* Responsive Video Embed */
.video-stage {
  background-color: var(--bg-card);
  border: 1px solid var(--border-color);
  border-radius: 0.75rem;
  overflow: hidden;
}

.video-container {
  position: relative;
  width: 100%;
  padding-bottom: 56.25%; /* 16:9 Aspect Ratio */
  background-color: #000000;
}

.video-container iframe {
  position: absolute;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  border: 0;
}

/* Video Details & Meta */
.video-meta-pane {
  padding: 1.5rem;
}

.lesson-badge {
  display: inline-flex;
  align-items: center;
  gap: 0.35rem;
  padding: 0.25rem 0.65rem;
  border-radius: 9999px;
  background-color: var(--badge-bg);
  color: var(--badge-text);
  font-size: 0.75rem;
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 0.05em;
  margin-bottom: 0.75rem;
}

.video-title {
  font-size: 1.75rem;
  font-weight: 700;
  margin-bottom: 1rem;
}

/* Navigation Controls (Next / Prev) */
.nav-controls-bar {
  display: flex;
  flex-wrap: wrap;
  gap: 1rem;
  justify-content: space-between;
  align-items: center;
  padding: 1.25rem 1.5rem;
  border-top: 1px solid var(--border-color);
  border-bottom: 1px solid var(--border-color);
  background-color: var(--bg-secondary);
}

.btn-nav {
  display: inline-flex;
  align-items: center;
  gap: 0.5rem;
  padding: 0.65rem 1.25rem;
  border-radius: 0.5rem;
  font-weight: 600;
  font-size: 0.9rem;
  transition: all 0.2s ease;
  border: 1px solid var(--border-color);
  background-color: var(--bg-card);
  color: var(--text-primary);
}

.btn-nav:hover:not(.disabled) {
  background-color: var(--accent);
  color: #ffffff;
  border-color: var(--accent);
  transform: translateY(-1px);
}

.btn-nav.disabled {
  opacity: 0.4;
  cursor: not-allowed;
  pointer-events: none;
}

.btn-primary {
  background-color: var(--accent);
  color: #ffffff;
  border-color: var(--accent);
}

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

.progress-counter {
  font-size: 0.875rem;
  color: var(--text-muted);
  font-weight: 500;
}

/* Video Description & Content Tabs */
.video-description-section {
  padding: 1.5rem;
  color: var(--text-secondary);
}

.notes-card {
  margin-top: 1.5rem;
  padding: 1.25rem;
  border-radius: 0.5rem;
  background-color: var(--bg-secondary);
  border-left: 3px solid var(--accent);
}

.notes-card h3 {
  font-size: 1rem;
  margin-bottom: 0.75rem;
}

.notes-card ul {
  padding-left: 1.25rem;
}

.hashtag-row {
  display: flex;
  flex-wrap: wrap;
  gap: 0.4rem;
  margin-top: 0.75rem;
}

.hashtag-chip {
  font-size: 0.75rem;
  font-weight: 600;
  color: var(--accent);
  border: 1px solid var(--border-color);
  border-radius: 999px;
  padding: 0.15rem 0.55rem;
}

.ref-links {
  display: flex;
  flex-wrap: wrap;
  gap: 0.75rem 1.25rem;
  margin-top: 1rem;
}

.ref-links a {
  color: var(--accent);
  font-size: 0.85rem;
  font-weight: 600;
}

.notes-card li {
  margin-bottom: 0.4rem;
  font-size: 0.9rem;
}

/* Sidebar / Table of Contents */
.toc-sidebar {
  background-color: var(--bg-card);
  border: 1px solid var(--border-color);
  border-radius: 0.75rem;
  overflow: hidden;
  position: sticky;
  top: 5.5rem;
  max-height: calc(100vh - 7rem);
  display: flex;
  flex-direction: column;
}

.toc-header {
  padding: 1.25rem;
  border-bottom: 1px solid var(--border-color);
  background-color: var(--bg-secondary);
}

.toc-header h2 {
  font-size: 1.15rem;
  font-weight: 700;
}

.toc-search-box {
  margin-top: 0.75rem;
}

.toc-search-input {
  width: 100%;
  padding: 0.5rem 0.75rem;
  border-radius: 0.375rem;
  border: 1px solid var(--border-color);
  background-color: var(--bg-primary);
  color: var(--text-primary);
  font-size: 0.85rem;
}

.toc-list {
  list-style: none;
  overflow-y: auto;
  padding: 0.5rem;
}

.toc-item {
  margin-bottom: 0.25rem;
}

.toc-link {
  display: flex;
  align-items: flex-start;
  gap: 0.75rem;
  padding: 0.75rem;
  border-radius: 0.5rem;
  transition: background-color 0.15s ease;
  font-size: 0.875rem;
}

.toc-link:hover {
  background-color: var(--bg-secondary);
}

.toc-link.active {
  background-color: var(--badge-bg);
  color: var(--badge-text);
  font-weight: 600;
  border-left: 3px solid var(--accent);
}

.toc-number {
  flex-shrink: 0;
  width: 1.5rem;
  height: 1.5rem;
  border-radius: 50%;
  background-color: var(--border-color);
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 0.75rem;
  font-weight: 600;
}

.toc-link.active .toc-number {
  background-color: var(--accent);
  color: #ffffff;
}

.toc-details {
  flex: 1;
}

.toc-item-title {
  display: block;
  line-height: 1.35;
}

.toc-item-duration {
  font-size: 0.75rem;
  color: var(--text-muted);
  margin-top: 0.2rem;
  display: block;
}

/* AdSense Container Styles */
.adsense-container {
  width: 100%;
  overflow: hidden;
  border-radius: 0.5rem;
}

.ad-placeholder {
  border: 1px dashed var(--border-color);
  background-color: var(--ad-bg);
  padding: 1rem;
  border-radius: 0.5rem;
  text-align: center;
  margin-bottom: 0.5rem;
}

.ad-badge {
  font-size: 0.7rem;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 0.08em;
  color: var(--text-muted);
  margin-bottom: 0.25rem;
}

.ad-info {
  display: flex;
  justify-content: center;
  gap: 1rem;
  font-size: 0.8rem;
  color: var(--text-secondary);
  font-family: monospace;
}

.ad-client {
  font-size: 0.7rem;
  color: var(--text-muted);
  margin-top: 0.25rem;
}

.landing-summary {
  font-size: 1.05rem;
  color: var(--text-secondary);
  max-width: 46rem;
  margin: 1.25rem 0 1.75rem;
  display: flex;
  flex-direction: column;
  gap: 1rem;
  line-height: 1.75;
}

.landing-lede {
  font-size: 1.1rem;
  color: var(--text-secondary);
  max-width: 46rem;
  margin-bottom: 0.75rem;
}

.landing-summary p {
  margin: 0;
}

/* Footer */
.site-footer {
  border-top: 1px solid var(--border-color);
  background-color: var(--bg-secondary);
  padding: 3rem 0;
  margin-top: 4rem;
  font-size: 0.875rem;
  color: var(--text-muted);
}

.footer-content {
  display: flex;
  flex-wrap: wrap;
  justify-content: space-between;
  align-items: center;
  gap: 1.5rem;
}

/* Playlist Card Grid for Landing Page */
.hero-banner {
  padding: 4rem 0 3rem 0;
  text-align: center;
  border-bottom: 1px solid var(--border-color);
  background-color: var(--bg-secondary);
}

.hero-title {
  font-size: 2.75rem;
  font-weight: 800;
  margin-bottom: 1rem;
  letter-spacing: -0.025em;
}

.hero-lead {
  font-size: 1.15rem;
  max-width: 680px;
  margin: 0 auto 1.5rem auto;
  color: var(--text-secondary);
}

.playlist-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(320px, 1fr));
  gap: 2rem;
  padding: 3rem 0;
}

.playlist-card {
  background-color: var(--bg-card);
  border: 1px solid var(--border-color);
  border-radius: 0.75rem;
  overflow: hidden;
  transition: transform 0.2s ease, box-shadow 0.2s ease;
  display: flex;
  flex-direction: column;
}

.playlist-card:hover {
  transform: translateY(-4px);
  border-color: var(--accent);
  box-shadow: 0 10px 25px -5px rgba(0,0,0,0.1);
}

.playlist-thumb {
  position: relative;
  width: 100%;
  padding-bottom: 56.25%;
  background-color: #000;
  overflow: hidden;
}

.playlist-thumb img {
  position: absolute;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  object-fit: cover;
}

.playlist-count-badge {
  position: absolute;
  bottom: 0.75rem;
  right: 0.75rem;
  background-color: rgba(0, 0, 0, 0.8);
  color: #fff;
  padding: 0.25rem 0.5rem;
  border-radius: 0.25rem;
  font-size: 0.75rem;
  font-weight: 600;
}

.playlist-card-body {
  padding: 1.5rem;
  flex: 1;
  display: flex;
  flex-direction: column;
}

.playlist-card-title {
  font-size: 1.25rem;
  font-weight: 700;
  margin-bottom: 0.5rem;
}

.playlist-card-desc {
  font-size: 0.875rem;
  color: var(--text-secondary);
  margin-bottom: 1.25rem;
  flex: 1;
}

.playlist-card-footer {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding-top: 1rem;
  border-top: 1px solid var(--border-color);
}