/* ==========================================================================
   BÙI VĂN NAM SƠN - DIGITAL ARCHIVE & KNOWLEDGE HUB
   Style: Editorial Academic Minimalist / Classical Swiss Typography
   ========================================================================== */

:root {
  /* Color Palette: Antique Parchment, Deep Ink, Crimson & Scholar Gold */
  --bg-parchment: #FBF9F5;
  --bg-parchment-deep: #F4EFEB;
  --bg-card: #FFFFFF;
  --bg-dark: #161514;
  --bg-dark-card: #201E1D;

  --text-main: #1C1B1A;
  --text-body: #3D3935;
  --text-muted: #7A746C;
  --text-light: #F7F5F0;
  --text-light-muted: #A8A196;

  --accent-crimson: #7A1F2D;
  --accent-crimson-hover: #962737;
  --accent-crimson-soft: #F9EBEF;
  --accent-gold: #B8860B;
  --accent-gold-light: #D4AF37;
  --accent-gold-soft: #FAF3E0;

  --border-light: #E7E0D6;
  --border-medium: #D0C6B8;
  --border-dark: #332F2C;

  /* Typography */
  --font-serif: 'Cormorant Garamond', 'Playfair Display', Georgia, serif;
  --font-display: 'Cinzel', 'Playfair Display', Georgia, serif;
  --font-sans: 'Plus Jakarta Sans', -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;

  /* Elevation */
  --shadow-sm: 0 2px 8px rgba(28, 27, 26, 0.04);
  --shadow-md: 0 8px 24px rgba(28, 27, 26, 0.08);
  --shadow-lg: 0 16px 40px rgba(28, 27, 26, 0.12);
  --shadow-book: 0 12px 30px rgba(0, 0, 0, 0.2), 0 2px 6px rgba(0, 0, 0, 0.15);

  /* Transitions */
  --transition-fast: 0.2s cubic-bezier(0.16, 1, 0.3, 1);
  --transition-normal: 0.35s cubic-bezier(0.16, 1, 0.3, 1);
  --transition-slow: 0.6s cubic-bezier(0.16, 1, 0.3, 1);

  /* Container */
  --max-width: 1240px;
  --header-height: 72px;
}

/* ==========================================================================
   SCHOLAR READING MODES (DARK & SEPIA THEMES)
   ========================================================================== */
[data-theme="dark"] {
  --bg-parchment: #121110;
  --bg-parchment-deep: #191816;
  --bg-card: #1F1D1B;
  --bg-dark: #0A0A09;
  --bg-dark-card: #151413;

  --text-main: #F2EDE4;
  --text-body: #D5CFC4;
  --text-muted: #9E9689;
  --text-light: #F7F5F0;
  --text-light-muted: #A8A196;

  --accent-crimson: #E05A68;
  --accent-crimson-hover: #ED6E7B;
  --accent-crimson-soft: #2B181A;
  --accent-gold: #E5A93C;
  --accent-gold-light: #F3C05A;
  --accent-gold-soft: #282010;

  --border-light: #2A2724;
  --border-medium: #3D3732;
  --border-dark: #504841;

  --shadow-sm: 0 2px 8px rgba(0, 0, 0, 0.35);
  --shadow-md: 0 8px 24px rgba(0, 0, 0, 0.5);
  --shadow-lg: 0 16px 40px rgba(0, 0, 0, 0.65);
  --shadow-book: 0 12px 30px rgba(0, 0, 0, 0.6), 0 2px 6px rgba(0, 0, 0, 0.4);
}

[data-theme="sepia"] {
  --bg-parchment: #F4EBDD;
  --bg-parchment-deep: #E8DCCB;
  --bg-card: #FAF4E9;
  --bg-dark: #221A14;
  --bg-dark-card: #2B211A;

  --text-main: #2D2016;
  --text-body: #49382B;
  --text-muted: #7E6C5A;

  --accent-crimson: #8B2836;
  --accent-crimson-hover: #A43242;
  --accent-crimson-soft: #F2E1E3;
  --accent-gold: #B07A16;
  --accent-gold-light: #C6922C;
  --accent-gold-soft: #F5E8CE;

  --border-light: #DFCFBB;
  --border-medium: #CAB7A0;

  --shadow-sm: 0 2px 8px rgba(45, 32, 22, 0.05);
  --shadow-md: 0 8px 24px rgba(45, 32, 22, 0.08);
  --shadow-lg: 0 16px 40px rgba(45, 32, 22, 0.12);
}

/* Base Reset */
*, *::before, *::after {
  box-sizing: border-box;
  margin: 0;
  padding: 0;
}

html {
  scroll-behavior: smooth;
  font-size: 16px;
  -webkit-text-size-adjust: 100%;
}

body {
  background-color: var(--bg-parchment);
  color: var(--text-body);
  font-family: var(--font-sans);
  line-height: 1.68;
  font-weight: 400;
  overflow-x: hidden;
  background-image: radial-gradient(var(--border-light) 0.75px, transparent 0.75px);
  background-size: 28px 28px;
}

/* Selection */
::selection {
  background-color: var(--accent-crimson);
  color: #FFFFFF;
}

/* Typography Hierarchy */
h1, h2, h3, h4, .font-serif {
  font-family: var(--font-serif);
  color: var(--text-main);
  line-height: 1.25;
  font-weight: 600;
}

h1 { font-size: clamp(2.4rem, 4.5vw, 4rem); letter-spacing: -0.02em; }
h2 { font-size: clamp(1.8rem, 3.2vw, 2.75rem); letter-spacing: -0.01em; }
h3 { font-size: clamp(1.3rem, 2vw, 1.75rem); }
h4 { font-size: 1.15rem; }

p {
  margin-bottom: 1rem;
}

a {
  color: var(--accent-crimson);
  text-decoration: none;
  transition: color var(--transition-fast);
}

a:hover {
  color: var(--accent-crimson-hover);
}

img, svg {
  display: block;
  max-width: 100%;
}

button, input, textarea, select {
  font-family: inherit;
  font-size: inherit;
}

.container {
  width: 100%;
  max-width: var(--max-width);
  margin: 0 auto;
  padding: 0 1.5rem;
}

/* Section Common */
.section-padding {
  padding: 5.5rem 0;
}

.section-header {
  text-align: center;
  max-width: 780px;
  margin: 0 auto 3.5rem;
}

.section-tag {
  display: inline-block;
  font-family: var(--font-sans);
  font-size: 0.78rem;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 0.14em;
  color: var(--accent-crimson);
  background-color: var(--accent-crimson-soft);
  padding: 0.35rem 0.9rem;
  border-radius: 999px;
  margin-bottom: 1rem;
  border: 1px solid rgba(122, 31, 45, 0.15);
}

.section-tag.gold {
  color: var(--accent-gold);
  background-color: var(--accent-gold-soft);
  border-color: rgba(184, 134, 11, 0.2);
}

.section-desc {
  font-size: 1.08rem;
  color: var(--text-muted);
  margin-top: 0.75rem;
  font-family: var(--font-sans);
}

/* ==========================================================================
   NAVIGATION BAR
   ========================================================================== */
.reading-bar {
  position: fixed;
  top: 0;
  left: 0;
  height: 3px;
  width: 0%;
  background: linear-gradient(90deg, var(--accent-crimson), var(--accent-gold));
  z-index: 1001;
  transition: width 0.1s ease;
}

.site-header {
  position: fixed;
  top: 0;
  left: 0;
  width: 100%;
  height: var(--header-height);
  background: rgba(251, 249, 245, 0.92);
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
  border-bottom: 1px solid var(--border-light);
  z-index: 1000;
  transition: all var(--transition-normal);
}

.site-header.scrolled {
  box-shadow: var(--shadow-sm);
  background: rgba(251, 249, 245, 0.98);
}

.header-inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: 100%;
}

.brand-logo {
  display: flex;
  align-items: center;
  gap: 0.85rem;
  text-decoration: none;
}

.monogram {
  width: 42px;
  height: 42px;
  background-color: var(--bg-dark);
  color: var(--accent-gold-light);
  border: 1px solid var(--accent-gold);
  border-radius: 4px;
  display: flex;
  align-items: center;
  justify-content: center;
  font-family: var(--font-serif);
  font-weight: 700;
  font-size: 1.25rem;
  letter-spacing: 0.05em;
  transition: transform var(--transition-fast);
}

.brand-logo:hover .monogram {
  transform: rotate(4deg) scale(1.04);
}

.brand-info {
  display: flex;
  flex-direction: column;
}

.brand-name {
  font-family: var(--font-serif);
  font-size: 1.2rem;
  font-weight: 700;
  color: var(--text-main);
  letter-spacing: 0.02em;
  line-height: 1.1;
}

.brand-sub {
  font-size: 0.68rem;
  font-weight: 600;
  letter-spacing: 0.12em;
  text-transform: uppercase;
  color: var(--text-muted);
}

.site-nav {
  display: flex;
  align-items: center;
  gap: 1.8rem;
}

.site-nav a {
  font-size: 0.9rem;
  font-weight: 500;
  color: var(--text-body);
  position: relative;
  padding: 0.25rem 0;
}

.site-nav a::after {
  content: '';
  position: absolute;
  bottom: 0;
  left: 0;
  width: 0;
  height: 1.5px;
  background-color: var(--accent-crimson);
  transition: width var(--transition-fast);
}

.site-nav a:hover {
  color: var(--accent-crimson);
}

.site-nav a:hover::after {
  width: 100%;
}

.header-actions {
  display: flex;
  align-items: center;
  gap: 0.9rem;
}

.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 0.5rem;
  padding: 0.65rem 1.25rem;
  font-size: 0.88rem;
  font-weight: 600;
  border-radius: 4px;
  cursor: pointer;
  border: 1px solid transparent;
  transition: all var(--transition-fast);
  text-decoration: none;
}

.btn-crimson {
  background-color: var(--accent-crimson);
  color: #FFFFFF;
  border-color: var(--accent-crimson);
}

.btn-crimson:hover {
  background-color: var(--accent-crimson-hover);
  color: #FFFFFF;
  transform: translateY(-1px);
  box-shadow: 0 4px 12px rgba(122, 31, 45, 0.25);
}

.btn-outline {
  background-color: transparent;
  color: var(--text-main);
  border-color: var(--border-medium);
}

.btn-outline:hover {
  border-color: var(--accent-crimson);
  color: var(--accent-crimson);
  background-color: var(--accent-crimson-soft);
}

.btn-gold {
  background-color: var(--accent-gold);
  color: #FFFFFF;
  border-color: var(--accent-gold);
}

.btn-gold:hover {
  background-color: #A07408;
  color: #FFFFFF;
  transform: translateY(-1px);
}

.btn-sm {
  padding: 0.45rem 0.9rem;
  font-size: 0.8rem;
}

/* Mobile Nav Toggle */
.mobile-toggle {
  display: none;
  background: none;
  border: none;
  cursor: pointer;
  padding: 0.5rem;
  color: var(--text-main);
}

/* ==========================================================================
   HERO / A1: IDENTITY & LEGACY
   ========================================================================== */
.hero-section {
  padding-top: calc(var(--header-height) + 3.5rem);
  padding-bottom: 4.5rem;
  position: relative;
  overflow: hidden;
}

.hero-grid {
  display: grid;
  grid-template-columns: 1.15fr 0.85fr;
  gap: 3.5rem;
  align-items: center;
}

.hero-identity {
  display: flex;
  align-items: center;
  gap: 0.75rem;
  margin-bottom: 1.25rem;
}

.hero-pretitle {
  font-size: 0.82rem;
  font-weight: 700;
  letter-spacing: 0.16em;
  text-transform: uppercase;
  color: var(--accent-crimson);
}

.hero-divider {
  width: 28px;
  height: 1px;
  background-color: var(--accent-crimson);
}

.hero-title {
  margin-bottom: 1.25rem;
  font-size: clamp(2.6rem, 4.8vw, 4.2rem);
  font-family: var(--font-serif);
  line-height: 1.12;
}

.hero-title em {
  font-style: italic;
  font-weight: 400;
  color: var(--accent-crimson);
}

.hero-tagline {
  font-size: 1.15rem;
  color: var(--text-muted);
  margin-bottom: 1.75rem;
  line-height: 1.75;
  font-family: var(--font-sans);
}

/* Classical Quote Box */
.hero-quote-box {
  background: var(--bg-card);
  border-left: 3px solid var(--accent-gold);
  border-top: 1px solid var(--border-light);
  border-right: 1px solid var(--border-light);
  border-bottom: 1px solid var(--border-light);
  padding: 1.35rem 1.5rem;
  margin-bottom: 2rem;
  border-radius: 0 6px 6px 0;
  box-shadow: var(--shadow-sm);
  position: relative;
}

.quote-mark {
  font-family: var(--font-serif);
  font-size: 2.8rem;
  line-height: 0.8;
  color: var(--accent-gold);
  opacity: 0.35;
  position: absolute;
  top: 0.85rem;
  left: 0.65rem;
}

.quote-text {
  font-family: var(--font-serif);
  font-size: 1.18rem;
  font-style: italic;
  color: var(--text-main);
  line-height: 1.6;
  margin-bottom: 0.5rem;
  padding-left: 1.2rem;
}

.quote-author {
  font-size: 0.78rem;
  font-weight: 600;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  color: var(--text-muted);
  padding-left: 1.2rem;
}

.hero-cta-group {
  display: flex;
  flex-wrap: wrap;
  gap: 1rem;
  margin-bottom: 2.5rem;
}

/* Stats Row */
.stats-strip {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 1.25rem;
  padding-top: 2rem;
  border-top: 1px solid var(--border-light);
}

.stat-item {
  display: flex;
  flex-direction: column;
}

.stat-num {
  font-family: var(--font-serif);
  font-size: 2.1rem;
  font-weight: 700;
  color: var(--accent-crimson);
  line-height: 1.1;
}

.stat-lbl {
  font-size: 0.78rem;
  color: var(--text-muted);
  font-weight: 500;
  line-height: 1.35;
  margin-top: 0.25rem;
}

/* Hero Media Frame (YouTube Video & Visual) */
.hero-visual {
  position: relative;
  width: 100%;
}

.video-frame {
  position: relative;
  background-color: var(--bg-dark);
  padding: 10px;
  border-radius: 8px;
  box-shadow: var(--shadow-lg);
  border: 1px solid var(--accent-gold);
}

.video-responsive-wrap {
  position: relative;
  padding-bottom: 56.25%; /* 16:9 Aspect Ratio */
  height: 0;
  overflow: hidden;
  border-radius: 4px;
  background: #000000;
}

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

.video-corner {
  position: absolute;
  width: 16px;
  height: 16px;
  border: 2px solid var(--accent-gold);
  z-index: 5;
}

.video-corner.tl { top: -4px; left: -4px; border-right: none; border-bottom: none; }
.video-corner.tr { top: -4px; right: -4px; border-left: none; border-bottom: none; }
.video-corner.bl { bottom: -4px; left: -4px; border-right: none; border-top: none; }
.video-corner.br { bottom: -4px; right: -4px; border-left: none; border-top: none; }

.video-caption-bar {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 0.75rem 0.5rem 0.25rem;
  font-size: 0.82rem;
  color: var(--text-light-muted);
}

.video-badge-tag {
  font-size: 0.68rem;
  font-weight: 700;
  letter-spacing: 0.12em;
  text-transform: uppercase;
  color: var(--accent-gold-light);
  background: rgba(212, 175, 55, 0.15);
  padding: 0.2rem 0.6rem;
  border-radius: 3px;
  border: 1px solid rgba(212, 175, 55, 0.3);
}

.video-source-link {
  color: var(--text-light-muted);
  text-decoration: none;
  font-size: 0.75rem;
  display: flex;
  align-items: center;
  gap: 0.3rem;
}

.video-source-link:hover {
  color: #FFFFFF;
}

/* Legacy Portrait Frame Support */
.portrait-frame {
  position: relative;
  background-color: var(--bg-dark);
  padding: 12px;
  border-radius: 8px;
  box-shadow: var(--shadow-lg);
  border: 1px solid var(--accent-gold);
}

.portrait-img {
  width: 100%;
  height: auto;
  border-radius: 4px;
  display: block;
}

.badge-text strong {
  display: block;
  font-size: 0.84rem;
  color: var(--text-main);
  line-height: 1.2;
}

.badge-text span {
  font-size: 0.72rem;
  color: var(--text-muted);
}

/* ==========================================================================
   TIMELINE / SCHOLAR MILESTONES
   ========================================================================== */
.milestones-strip {
  background-color: var(--bg-parchment-deep);
  border-top: 1px solid var(--border-light);
  border-bottom: 1px solid var(--border-light);
  padding: 3rem 0;
}

.milestones-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 2rem;
}

.milestone-card {
  background: var(--bg-card);
  padding: 1.75rem;
  border-radius: 6px;
  border: 1px solid var(--border-light);
  transition: transform var(--transition-fast), box-shadow var(--transition-fast);
}

.milestone-card:hover {
  transform: translateY(-3px);
  box-shadow: var(--shadow-md);
  border-color: var(--accent-gold);
}

.milestone-year {
  font-family: var(--font-serif);
  font-size: 1.15rem;
  font-weight: 700;
  color: var(--accent-crimson);
  margin-bottom: 0.4rem;
}

.milestone-title {
  font-family: var(--font-serif);
  font-size: 1.25rem;
  font-weight: 700;
  color: var(--text-main);
  margin-bottom: 0.65rem;
}

.milestone-desc {
  font-size: 0.88rem;
  color: var(--text-muted);
  line-height: 1.6;
  margin-bottom: 0;
}

/* ==========================================================================
   A2: WORKS & TRANSLATIONS (TỦ SÁCH HÀN LÂM)
   ========================================================================== */
.books-filter-bar {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 0.75rem;
  flex-wrap: wrap;
  margin-bottom: 3rem;
}

.filter-btn {
  background: var(--bg-card);
  border: 1px solid var(--border-medium);
  padding: 0.55rem 1.25rem;
  font-size: 0.85rem;
  font-weight: 600;
  color: var(--text-body);
  border-radius: 999px;
  cursor: pointer;
  transition: all var(--transition-fast);
}

.filter-btn:hover {
  border-color: var(--accent-crimson);
  color: var(--accent-crimson);
}

.filter-btn.active {
  background-color: var(--accent-crimson);
  color: #FFFFFF;
  border-color: var(--accent-crimson);
  box-shadow: 0 2px 8px rgba(122, 31, 45, 0.25);
}

.books-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(280px, 1fr));
  gap: 2.25rem;
}

.book-card {
  background: var(--bg-card);
  border-radius: 8px;
  border: 1px solid var(--border-light);
  overflow: hidden;
  display: flex;
  flex-direction: column;
  transition: transform var(--transition-normal), box-shadow var(--transition-normal);
  position: relative;
}

.book-card:hover {
  transform: translateY(-6px);
  box-shadow: var(--shadow-lg);
  border-color: var(--border-medium);
}

.book-cover-wrap {
  position: relative;
  background-color: #0E0D0C;
  padding: 1.75rem 2rem;
  display: flex;
  align-items: center;
  justify-content: center;
  cursor: pointer;
}

.book-cover-img {
  width: 100%;
  max-width: 200px;
  height: auto;
  aspect-ratio: 2/3;
  box-shadow: var(--shadow-book);
  border-radius: 4px;
  transition: transform var(--transition-normal);
}

.book-card:hover .book-cover-img {
  transform: scale(1.03) rotate(0.5deg);
}

.book-badge {
  position: absolute;
  top: 1rem;
  left: 1rem;
  background: rgba(26, 24, 23, 0.85);
  backdrop-filter: blur(4px);
  color: var(--accent-gold-light);
  font-size: 0.7rem;
  font-weight: 700;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  padding: 0.3rem 0.65rem;
  border-radius: 3px;
  border: 1px solid rgba(212, 175, 55, 0.3);
}

.book-info {
  padding: 1.5rem;
  display: flex;
  flex-direction: column;
  flex-grow: 1;
}

.book-meta {
  display: flex;
  align-items: center;
  justify-content: space-between;
  font-size: 0.78rem;
  color: var(--text-muted);
  margin-bottom: 0.5rem;
  text-transform: uppercase;
  letter-spacing: 0.06em;
}

.book-title {
  font-family: var(--font-serif);
  font-size: 1.4rem;
  font-weight: 700;
  line-height: 1.25;
  margin-bottom: 0.3rem;
  color: var(--text-main);
}

.book-original-title {
  font-family: var(--font-serif);
  font-style: italic;
  font-size: 0.92rem;
  color: var(--accent-crimson);
  margin-bottom: 0.85rem;
}

.book-summary {
  font-size: 0.86rem;
  color: var(--text-muted);
  line-height: 1.6;
  margin-bottom: 1.25rem;
  display: -webkit-box;
  -webkit-line-clamp: 3;
  -webkit-box-orient: vertical;
  overflow: hidden;
  flex-grow: 1;
}

.book-actions {
  display: flex;
  align-items: center;
  gap: 0.65rem;
  padding-top: 1rem;
  border-top: 1px solid var(--border-light);
}

.book-actions .btn {
  flex: 1;
}

/* ==========================================================================
   A3: COURSES & SEMINARS (KHÓA HỌC & CHUYÊN ĐỀ)
   ========================================================================== */
.courses-section {
  background-color: var(--bg-parchment-deep);
  border-top: 1px solid var(--border-light);
  border-bottom: 1px solid var(--border-light);
}

.courses-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(340px, 1fr));
  gap: 2rem;
}

.course-card {
  background: var(--bg-card);
  border-radius: 8px;
  border: 1px solid var(--border-light);
  padding: 2.25rem;
  display: flex;
  flex-direction: column;
  box-shadow: var(--shadow-sm);
  transition: transform var(--transition-fast), border-color var(--transition-fast);
}

.course-card:hover {
  transform: translateY(-4px);
  border-color: var(--accent-crimson);
  box-shadow: var(--shadow-md);
}

.course-header-meta {
  display: flex;
  align-items: center;
  justify-content: space-between;
  margin-bottom: 1rem;
}

.course-level {
  font-size: 0.74rem;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 0.1em;
  color: var(--accent-crimson);
  background: var(--accent-crimson-soft);
  padding: 0.25rem 0.65rem;
  border-radius: 999px;
}

.course-status {
  font-size: 0.78rem;
  font-weight: 600;
  color: #2E7D32;
  display: flex;
  align-items: center;
  gap: 0.35rem;
}

.course-status::before {
  content: '';
  width: 7px;
  height: 7px;
  background-color: #2E7D32;
  border-radius: 50%;
  display: inline-block;
}

.course-title {
  font-family: var(--font-serif);
  font-size: 1.5rem;
  font-weight: 700;
  line-height: 1.28;
  margin-bottom: 0.75rem;
}

.course-instructor {
  font-size: 0.85rem;
  font-weight: 600;
  color: var(--text-muted);
  margin-bottom: 1rem;
}

.course-desc {
  font-size: 0.9rem;
  color: var(--text-body);
  line-height: 1.65;
  margin-bottom: 1.5rem;
}

.course-specs {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 0.75rem;
  padding: 1rem;
  background-color: var(--bg-parchment);
  border-radius: 6px;
  margin-bottom: 1.5rem;
  font-size: 0.82rem;
}

.spec-label {
  color: var(--text-muted);
  display: block;
  font-size: 0.72rem;
  text-transform: uppercase;
  letter-spacing: 0.05em;
}

.spec-val {
  font-weight: 600;
  color: var(--text-main);
}

.course-modules-list {
  list-style: none;
  margin-bottom: 1.75rem;
  flex-grow: 1;
}

.course-modules-list li {
  font-size: 0.86rem;
  color: var(--text-muted);
  padding: 0.4rem 0;
  border-bottom: 1px dashed var(--border-light);
  display: flex;
  align-items: flex-start;
  gap: 0.5rem;
}

.course-modules-list li::before {
  content: "✦";
  color: var(--accent-gold);
  font-size: 0.7rem;
  margin-top: 0.15rem;
}

/* ==========================================================================
   A4: COMMUNITY HUB (SUBSTACK & ZALO CONVERSION)
   ========================================================================== */
.community-grid {
  display: grid;
  grid-template-columns: 1.25fr 0.75fr;
  gap: 3rem;
  align-items: start;
}

.substack-card {
  background: var(--bg-card);
  border: 1px solid var(--border-medium);
  border-radius: 8px;
  padding: 2.5rem;
  box-shadow: var(--shadow-sm);
}

.substack-header {
  display: flex;
  align-items: center;
  gap: 1.25rem;
  margin-bottom: 1.75rem;
  padding-bottom: 1.5rem;
  border-bottom: 1px solid var(--border-light);
}

.substack-icon {
  width: 54px;
  height: 54px;
  background-color: #FF6719;
  border-radius: 8px;
  display: flex;
  align-items: center;
  justify-content: center;
  color: #FFFFFF;
  font-size: 1.8rem;
  font-family: var(--font-serif);
  font-weight: 700;
}

.substack-title h3 {
  font-size: 1.55rem;
  margin-bottom: 0.2rem;
}

.substack-meta {
  font-size: 0.82rem;
  color: var(--text-muted);
}

.substack-articles-list {
  display: flex;
  flex-direction: column;
  gap: 1.25rem;
  margin-bottom: 2rem;
}

.article-row {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 1rem 1.25rem;
  background: var(--bg-parchment);
  border-radius: 6px;
  border: 1px solid var(--border-light);
  transition: all var(--transition-fast);
}

.article-row:hover {
  background: #FFFFFF;
  border-color: var(--accent-crimson);
  transform: translateX(4px);
}

.article-info h4 {
  font-size: 1.05rem;
  font-family: var(--font-serif);
  margin-bottom: 0.25rem;
  color: var(--text-main);
}

.article-meta {
  font-size: 0.78rem;
  color: var(--text-muted);
}

.article-link-icon {
  color: var(--accent-crimson);
  font-size: 1.2rem;
}

/* Side Channels (Zalo & Facebook) */
.channels-column {
  display: flex;
  flex-direction: column;
  gap: 1.5rem;
}

.channel-card {
  background: var(--bg-card);
  border: 1px solid var(--border-light);
  border-radius: 8px;
  padding: 1.75rem;
  box-shadow: var(--shadow-sm);
  transition: transform var(--transition-fast), border-color var(--transition-fast);
}

.channel-card:hover {
  transform: translateY(-3px);
  box-shadow: var(--shadow-md);
}

.channel-card.zalo {
  border-left: 4px solid #0068FF;
}

.channel-card.facebook {
  border-left: 4px solid #1877F2;
}

.channel-header {
  display: flex;
  align-items: center;
  gap: 1rem;
  margin-bottom: 0.85rem;
}

.channel-avatar {
  width: 44px;
  height: 44px;
  border-radius: 8px;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 1.4rem;
  color: #FFFFFF;
}

.channel-avatar.zalo-bg { background-color: #0068FF; }
.channel-avatar.fb-bg { background-color: #1877F2; }

.channel-title h4 {
  font-size: 1.15rem;
  margin-bottom: 0.15rem;
}

.channel-members {
  font-size: 0.78rem;
  color: var(--text-muted);
  font-weight: 600;
}

.channel-card p {
  font-size: 0.88rem;
  color: var(--text-body);
  margin-bottom: 1.25rem;
}

/* ==========================================================================
   A5: DIGITAL ARCHIVE INITIATIVE (CỔNG LƯU TRỮ SỐ HÓA)
   ========================================================================== */
.archive-section {
  background-color: var(--bg-dark);
  color: var(--text-light);
  border-top: 1px solid var(--border-dark);
  position: relative;
}

.archive-section h2, .archive-section h3 {
  color: #FFFFFF;
}

.archive-section .section-desc {
  color: var(--text-light-muted);
}

.archive-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 2rem;
  margin-bottom: 3.5rem;
}

.archive-card {
  background-color: var(--bg-dark-card);
  border: 1px solid var(--border-dark);
  border-radius: 8px;
  padding: 2rem;
  transition: transform var(--transition-fast), border-color var(--transition-fast);
}

.archive-card:hover {
  transform: translateY(-4px);
  border-color: var(--accent-gold);
}

.archive-category {
  font-size: 0.76rem;
  font-weight: 700;
  letter-spacing: 0.12em;
  text-transform: uppercase;
  color: var(--accent-gold-light);
  margin-bottom: 0.85rem;
  display: block;
}

.archive-card h3 {
  font-size: 1.35rem;
  margin-bottom: 0.75rem;
}

.archive-card p {
  font-size: 0.9rem;
  color: var(--text-light-muted);
  line-height: 1.6;
  margin-bottom: 0;
}

/* Early Access Lead Capture Banner */
.early-access-banner {
  background: linear-gradient(135deg, #242220 0%, #171514 100%);
  border: 1px solid var(--accent-gold);
  border-radius: 8px;
  padding: 3rem;
  display: grid;
  grid-template-columns: 1.2fr 0.8fr;
  gap: 2.5rem;
  align-items: center;
  box-shadow: 0 20px 50px rgba(0, 0, 0, 0.5);
}

.early-access-info h3 {
  font-size: 1.85rem;
  margin-bottom: 0.65rem;
  color: #FFFFFF;
}

.early-access-info p {
  font-size: 0.95rem;
  color: var(--text-light-muted);
  margin-bottom: 0;
}

.early-access-form {
  display: flex;
  flex-direction: column;
  gap: 0.85rem;
}

.form-row {
  display: flex;
  gap: 0.5rem;
}

.input-field {
  width: 100%;
  padding: 0.75rem 1rem;
  border-radius: 4px;
  border: 1px solid var(--border-dark);
  background-color: #0E0D0C;
  color: #FFFFFF;
  font-size: 0.9rem;
  outline: none;
  transition: border-color var(--transition-fast);
}

.input-field:focus {
  border-color: var(--accent-gold-light);
}

.early-access-form small {
  font-size: 0.74rem;
  color: var(--text-light-muted);
}

/* ==========================================================================
   PHILOSOPHY GLOSSARY / ACADEMIC VOCABULARY CARDS
   ========================================================================== */
.glossary-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(340px, 1fr));
  gap: 1.75rem;
}

.glossary-card {
  background: var(--bg-card);
  border: 1px solid var(--border-light);
  border-radius: 8px;
  padding: 1.75rem;
  display: flex;
  flex-direction: column;
  box-shadow: var(--shadow-sm);
  transition: transform var(--transition-fast), border-color var(--transition-fast), box-shadow var(--transition-fast);
  position: relative;
}

.glossary-card:hover {
  transform: translateY(-3px);
  border-color: var(--accent-gold);
  box-shadow: var(--shadow-md);
}

.glossary-header {
  display: flex;
  align-items: flex-start;
  justify-content: space-between;
  margin-bottom: 0.75rem;
  padding-bottom: 0.75rem;
  border-bottom: 1px solid var(--border-light);
}

.glossary-original {
  font-family: var(--font-serif);
  font-size: 1.35rem;
  font-weight: 700;
  color: var(--accent-crimson);
  line-height: 1.2;
}

.glossary-lang-badge {
  font-size: 0.7rem;
  font-weight: 700;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  color: var(--accent-gold);
  background: var(--accent-gold-soft);
  padding: 0.2rem 0.55rem;
  border-radius: 4px;
}

.glossary-vn-term {
  font-family: var(--font-serif);
  font-size: 1.12rem;
  font-weight: 600;
  color: var(--text-main);
  margin-bottom: 0.65rem;
}

.glossary-desc {
  font-size: 0.88rem;
  color: var(--text-body);
  line-height: 1.65;
  margin-bottom: 1rem;
  flex-grow: 1;
}

.glossary-citation {
  font-size: 0.76rem;
  font-style: italic;
  color: var(--text-muted);
  padding-top: 0.65rem;
  border-top: 1px dashed var(--border-light);
  display: flex;
  align-items: center;
  gap: 0.35rem;
}

.glossary-citation::before {
  content: "📖";
  font-style: normal;
  font-size: 0.8rem;
}

/* ==========================================================================
   MODAL WINDOWS (READING ROOM & REGISTRATION)
   ========================================================================== */
.modal-overlay {
  position: fixed;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  background: rgba(14, 13, 12, 0.75);
  backdrop-filter: blur(6px);
  z-index: 2000;
  display: flex;
  align-items: center;
  justify-content: center;
  padding: 1.5rem;
  opacity: 0;
  visibility: hidden;
  transition: all var(--transition-normal);
}

.modal-overlay.active {
  opacity: 1;
  visibility: visible;
}

.modal-container {
  background: var(--bg-parchment);
  width: 100%;
  max-width: 720px;
  max-height: 90vh;
  border-radius: 8px;
  border: 1px solid var(--border-medium);
  box-shadow: 0 25px 60px rgba(0, 0, 0, 0.35);
  overflow-y: auto;
  position: relative;
  transform: translateY(20px) scale(0.97);
  transition: transform var(--transition-normal);
}

.modal-overlay.active .modal-container {
  transform: translateY(0) scale(1);
}

.modal-close-btn {
  position: absolute;
  top: 1.25rem;
  right: 1.25rem;
  width: 36px;
  height: 36px;
  background: var(--bg-card);
  border: 1px solid var(--border-light);
  border-radius: 50%;
  cursor: pointer;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 1.2rem;
  color: var(--text-main);
  transition: all var(--transition-fast);
  z-index: 10;
}

.modal-close-btn:hover {
  background-color: var(--accent-crimson);
  color: #FFFFFF;
  border-color: var(--accent-crimson);
}

.modal-header {
  padding: 2.25rem 2.25rem 1.25rem;
  border-bottom: 1px solid var(--border-light);
}

.modal-header h3 {
  font-size: 1.75rem;
  margin-bottom: 0.3rem;
}

.modal-subtitle {
  font-size: 0.88rem;
  color: var(--text-muted);
}

.modal-body {
  padding: 2rem 2.25rem;
}

/* Modal Book Reader Specific */
.modal-book-excerpt {
  background: var(--bg-card);
  padding: 1.5rem;
  border-left: 3px solid var(--accent-crimson);
  border-radius: 4px;
  font-family: var(--font-serif);
  font-size: 1.12rem;
  font-style: italic;
  line-height: 1.7;
  color: var(--text-main);
  margin-bottom: 1.75rem;
}

.modal-toc-list {
  list-style: decimal inside;
  margin-bottom: 2rem;
}

.modal-toc-list li {
  padding: 0.45rem 0;
  border-bottom: 1px solid var(--border-light);
  font-size: 0.92rem;
}

.modal-footer {
  padding: 1.25rem 2.25rem;
  background-color: var(--bg-parchment-deep);
  border-top: 1px solid var(--border-light);
  display: flex;
  align-items: center;
  justify-content: flex-end;
  gap: 1rem;
}

/* Form Styles inside Modal */
.modal-form {
  display: flex;
  flex-direction: column;
  gap: 1.25rem;
}

.form-group {
  display: flex;
  flex-direction: column;
  gap: 0.35rem;
}

.form-group label {
  font-size: 0.84rem;
  font-weight: 600;
  color: var(--text-main);
}

.form-control {
  width: 100%;
  padding: 0.75rem 1rem;
  border-radius: 4px;
  border: 1px solid var(--border-medium);
  background: #FFFFFF;
  font-size: 0.92rem;
  outline: none;
  transition: border-color var(--transition-fast);
}

.form-control:focus {
  border-color: var(--accent-crimson);
  box-shadow: 0 0 0 3px rgba(122, 31, 45, 0.1);
}

/* ==========================================================================
   TOAST NOTIFICATION
   ========================================================================== */
.toast-notice {
  position: fixed;
  bottom: 2rem;
  right: 2rem;
  background: var(--bg-dark);
  color: #FFFFFF;
  padding: 1rem 1.5rem;
  border-radius: 6px;
  border-left: 4px solid var(--accent-gold);
  box-shadow: var(--shadow-lg);
  font-size: 0.9rem;
  z-index: 3000;
  display: flex;
  align-items: center;
  gap: 0.85rem;
  transform: translateY(100px);
  opacity: 0;
  transition: all var(--transition-normal);
}

.toast-notice.show {
  transform: translateY(0);
  opacity: 1;
}

/* ==========================================================================
   FOOTER
   ========================================================================== */
.site-footer {
  background-color: #0E0D0C;
  color: var(--text-light-muted);
  padding: 5rem 0 2.5rem;
  border-top: 1px solid var(--border-dark);
}

.footer-top {
  display: grid;
  grid-template-columns: 1.5fr 1fr 1fr 1fr;
  gap: 3rem;
  margin-bottom: 4rem;
}

.footer-brand h4 {
  font-family: var(--font-serif);
  font-size: 1.5rem;
  color: #FFFFFF;
  margin-bottom: 0.75rem;
}

.footer-brand p {
  font-size: 0.88rem;
  line-height: 1.7;
}

.footer-col h5 {
  font-family: var(--font-sans);
  font-size: 0.82rem;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 0.12em;
  color: var(--accent-gold-light);
  margin-bottom: 1.25rem;
}

.footer-links {
  list-style: none;
  display: flex;
  flex-direction: column;
  gap: 0.65rem;
}

.footer-links a {
  font-size: 0.88rem;
  color: var(--text-light-muted);
  transition: color var(--transition-fast);
}

.footer-links a:hover {
  color: #FFFFFF;
}

.footer-bottom {
  padding-top: 2rem;
  border-top: 1px solid rgba(255, 255, 255, 0.08);
  display: flex;
  align-items: center;
  justify-content: space-between;
  font-size: 0.82rem;
}

.footer-quote {
  font-family: var(--font-serif);
  font-style: italic;
  color: var(--accent-gold-light);
}

/* ==========================================================================
   RESPONSIVE BREAKPOINTS
   ========================================================================== */
@media (max-width: 1024px) {
  .hero-grid {
    grid-template-columns: 1fr;
    gap: 3rem;
  }
  .hero-visual {
    max-width: 460px;
    margin: 0 auto;
  }
  .community-grid {
    grid-template-columns: 1fr;
  }
  .early-access-banner {
    grid-template-columns: 1fr;
  }
  .footer-top {
    grid-template-columns: 1fr 1fr;
    gap: 2.5rem;
  }
}

@media (max-width: 768px) {
  .section-padding {
    padding: 4rem 0;
  }
  .site-nav {
    display: none;
    position: absolute;
    top: var(--header-height);
    left: 0;
    width: 100%;
    background: var(--bg-parchment);
    flex-direction: column;
    padding: 1.5rem;
    border-bottom: 1px solid var(--border-medium);
    box-shadow: var(--shadow-md);
  }
  .site-nav.open {
    display: flex;
  }
  .mobile-toggle {
    display: block;
  }
  .stats-strip {
    grid-template-columns: repeat(2, 1fr);
    gap: 1.5rem;
  }
  .milestones-grid, .archive-grid {
    grid-template-columns: 1fr;
  }
  .early-access-banner {
    padding: 2rem 1.5rem;
  }
  .form-row {
    flex-direction: column;
  }
  .footer-top {
    grid-template-columns: 1fr;
  }
  .footer-bottom {
    flex-direction: column;
    gap: 1rem;
    text-align: center;
  }
}

/* ==========================================================================
   ACADEMIC ARTICLES ARCHIVE (triethoc.edu.vn)
   ========================================================================== */
.articles-section {
  background-color: var(--bg-card);
  border-top: 1px solid var(--border-light);
  border-bottom: 1px solid var(--border-light);
}

.articles-toolbar {
  display: flex;
  flex-direction: column;
  gap: 1.25rem;
  margin-bottom: 2.25rem;
}

.article-search-wrap {
  position: relative;
  max-width: 540px;
  margin: 0 auto;
  width: 100%;
}

.article-search-input {
  width: 100%;
  padding: 0.85rem 1.25rem 0.85rem 2.85rem;
  font-family: var(--font-sans);
  font-size: 0.95rem;
  background: var(--bg-parchment);
  border: 1px solid var(--border-medium);
  border-radius: 6px;
  color: var(--text-main);
  transition: all var(--transition-fast);
}

.article-search-input:focus {
  outline: none;
  border-color: var(--accent-gold);
  box-shadow: 0 0 0 3px var(--accent-gold-soft);
  background: #FFFFFF;
}

.article-search-icon {
  position: absolute;
  left: 1rem;
  top: 50%;
  transform: translateY(-50%);
  color: var(--text-muted);
  pointer-events: none;
}

.articles-filter-bar {
  display: flex;
  flex-wrap: wrap;
  justify-content: center;
  gap: 0.5rem;
}

.articles-filter-btn {
  background: var(--bg-parchment);
  border: 1px solid var(--border-light);
  border-radius: 20px;
  padding: 0.45rem 1.05rem;
  font-family: var(--font-sans);
  font-size: 0.82rem;
  font-weight: 500;
  color: var(--text-body);
  cursor: pointer;
  transition: all var(--transition-fast);
  display: inline-flex;
  align-items: center;
  gap: 0.35rem;
}

.articles-filter-btn:hover {
  border-color: var(--accent-gold);
  color: var(--accent-crimson);
}

.articles-filter-btn.active {
  background: var(--accent-crimson);
  border-color: var(--accent-crimson);
  color: #FFFFFF;
}

.articles-filter-btn .cat-count {
  font-size: 0.72rem;
  opacity: 0.8;
  background: rgba(0, 0, 0, 0.08);
  padding: 0.1rem 0.4rem;
  border-radius: 10px;
}

.articles-filter-btn.active .cat-count {
  background: rgba(255, 255, 255, 0.25);
  color: #FFFFFF;
}

.articles-archive-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(320px, 1fr));
  gap: 1.35rem;
  margin-bottom: 2rem;
}

.article-archive-card {
  background: var(--bg-parchment);
  border: 1px solid var(--border-light);
  border-radius: 6px;
  padding: 1.35rem;
  display: flex;
  flex-direction: column;
  justify-content: space-between;
  transition: all var(--transition-fast);
  text-decoration: none;
  color: inherit;
  box-shadow: 0 1px 3px rgba(0, 0, 0, 0.02);
}

.article-archive-card:hover {
  transform: translateY(-2px);
  border-color: var(--accent-gold);
  box-shadow: var(--shadow-sm);
}

.article-card-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  margin-bottom: 0.75rem;
  gap: 0.5rem;
}

.article-card-category {
  font-size: 0.72rem;
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 0.04em;
  color: var(--text-muted);
}

.article-card-role {
  font-size: 0.68rem;
  font-weight: 700;
  padding: 0.15rem 0.5rem;
  border-radius: 3px;
  background: var(--accent-gold-soft);
  color: var(--accent-gold-dark, #8C6D1F);
  border: 1px solid rgba(212, 175, 55, 0.25);
  white-space: nowrap;
}

.article-card-role.trans {
  background: rgba(139, 29, 39, 0.08);
  color: var(--accent-crimson);
  border-color: rgba(139, 29, 39, 0.2);
}

.article-card-title {
  font-family: var(--font-serif);
  font-size: 1.08rem;
  font-weight: 600;
  line-height: 1.45;
  color: var(--text-main);
  margin-bottom: 1rem;
  flex-grow: 1;
}

.article-archive-card:hover .article-card-title {
  color: var(--accent-crimson);
}

.article-card-footer {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding-top: 0.65rem;
  border-top: 1px dashed var(--border-light);
  font-size: 0.78rem;
  color: var(--text-muted);
}

.article-card-source {
  display: flex;
  align-items: center;
  gap: 0.35rem;
}

.article-card-action {
  color: var(--accent-crimson);
  font-weight: 600;
  display: inline-flex;
  align-items: center;
  gap: 0.25rem;
}

.articles-actions-bar {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 0.85rem;
  margin-top: 1.5rem;
}

.articles-count-status {
  font-size: 0.88rem;
  color: var(--text-muted);
}

/* ==========================================================================
   THEME SWITCHER COMPONENT
   ========================================================================== */
.theme-switcher {
  display: inline-flex;
  align-items: center;
  background: var(--bg-parchment-deep);
  border: 1px solid var(--border-medium);
  border-radius: 30px;
  padding: 3px;
  gap: 3px;
}

.theme-btn {
  background: transparent;
  border: none;
  width: 32px;
  height: 32px;
  border-radius: 50%;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  cursor: pointer;
  color: var(--text-muted);
  transition: all var(--transition-fast);
}

.theme-btn:hover {
  color: var(--text-main);
  background: rgba(0, 0, 0, 0.05);
}

[data-theme="dark"] .theme-btn:hover {
  background: rgba(255, 255, 255, 0.08);
}

.theme-btn.active {
  background: var(--bg-card);
  color: var(--accent-crimson);
  box-shadow: 0 1px 4px rgba(0, 0, 0, 0.12);
}

[data-theme="dark"] .theme-btn.active {
  color: var(--accent-gold);
}

/* Smooth Transition on Theme Switch */
body {
  transition: background-color var(--transition-normal), color var(--transition-normal);
}

.book-card, .milestone-card, .course-card, .archive-card, .glossary-card, 
.article-archive-card, .substack-card, .channel-card, .modal-container, .site-header {
  transition: background-color var(--transition-normal), border-color var(--transition-normal), color var(--transition-normal);
}

/* ==========================================================================
   PHILOSOPHICAL EPIGRAPH / QUOTE GENERATOR
   ========================================================================== */
.hero-quote-box {
  position: relative;
}

.hero-quote-footer {
  display: flex;
  align-items: center;
  justify-content: space-between;
  flex-wrap: wrap;
  gap: 0.85rem;
  margin-top: 1rem;
  padding-top: 0.85rem;
  border-top: 1px dashed var(--border-light);
}

.quote-shuffle-btn {
  display: inline-flex;
  align-items: center;
  gap: 0.45rem;
  background: var(--bg-card);
  border: 1px solid var(--border-medium);
  color: var(--text-main);
  font-family: var(--font-sans);
  font-size: 0.78rem;
  font-weight: 600;
  padding: 0.38rem 0.85rem;
  border-radius: 20px;
  cursor: pointer;
  box-shadow: var(--shadow-sm);
  transition: all var(--transition-fast);
}

.quote-shuffle-btn:hover {
  background: var(--accent-crimson);
  color: #FFFFFF;
  border-color: var(--accent-crimson);
  transform: translateY(-1px);
}

[data-theme="dark"] .quote-shuffle-btn:hover {
  background: var(--accent-gold);
  color: #121110;
  border-color: var(--accent-gold);
}

.quote-shuffle-btn svg {
  transition: transform 0.4s ease;
}

.quote-shuffle-btn:hover svg {
  transform: rotate(180deg);
}

.quote-text, .quote-author {
  transition: opacity 0.28s ease, transform 0.28s ease;
}

.quote-fade-out {
  opacity: 0;
  transform: translateY(6px);
}

.quote-fade-in {
  opacity: 1;
  transform: translateY(0);
}

/* ==========================================================================
   GLOSSARY TOOLBAR & LIVE SEARCH
   ========================================================================== */
.glossary-toolbar {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 0.85rem;
  margin-bottom: 2.75rem;
  max-width: 620px;
  margin-left: auto;
  margin-right: auto;
}

.glossary-search-wrap {
  position: relative;
  width: 100%;
}

.glossary-search-icon {
  position: absolute;
  left: 1.25rem;
  top: 50%;
  transform: translateY(-50%);
  color: var(--text-muted);
  pointer-events: none;
}

.glossary-search-input {
  width: 100%;
  padding: 0.85rem 1.25rem 0.85rem 3.1rem;
  background: var(--bg-card);
  border: 1px solid var(--border-medium);
  border-radius: 30px;
  font-family: var(--font-sans);
  font-size: 0.95rem;
  color: var(--text-main);
  outline: none;
  box-shadow: var(--shadow-sm);
  transition: all var(--transition-normal);
}

.glossary-search-input:focus {
  border-color: var(--accent-crimson);
  box-shadow: 0 0 0 3px rgba(122, 31, 45, 0.12);
}

[data-theme="dark"] .glossary-search-input:focus {
  border-color: var(--accent-gold);
  box-shadow: 0 0 0 3px rgba(229, 169, 60, 0.2);
}

.glossary-count {
  font-size: 0.84rem;
  color: var(--text-muted);
}

.glossary-empty {
  grid-column: 1 / -1;
  text-align: center;
  padding: 3rem 1.5rem;
  background: var(--bg-card);
  border: 1px dashed var(--border-medium);
  border-radius: 8px;
  color: var(--text-muted);
  font-size: 0.95rem;
}

/* Dark Mode Form Control refinement */
.form-control {
  background: var(--bg-card);
  color: var(--text-main);
}

/* ==========================================================================
   FACEBOOK ACADEMIC ACTIVITIES COMPONENT
   ========================================================================== */
.facebook-activities-strip {
  margin-top: 3.5rem;
  padding-top: 3rem;
  border-top: 1px solid var(--border-light);
}

.activities-strip-header {
  display: flex;
  align-items: flex-end;
  justify-content: space-between;
  flex-wrap: wrap;
  gap: 1.5rem;
  margin-bottom: 2rem;
}

.strip-header-info h3 {
  font-size: 1.6rem;
  margin-top: 0.45rem;
  margin-bottom: 0.35rem;
  color: var(--text-main);
}

.activities-badge {
  display: inline-flex;
  align-items: center;
  gap: 0.45rem;
  font-size: 0.72rem;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 0.08em;
  background: rgba(24, 119, 242, 0.1);
  color: #1877F2;
  border: 1px solid rgba(24, 119, 242, 0.25);
  padding: 0.25rem 0.65rem;
  border-radius: 20px;
}

[data-theme="dark"] .activities-badge {
  background: rgba(24, 119, 242, 0.2);
  color: #5B9DFF;
  border-color: rgba(24, 119, 242, 0.4);
}

.strip-desc {
  font-size: 0.92rem;
  color: var(--text-muted);
  max-width: 720px;
}

.facebook-activities-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(320px, 1fr));
  gap: 1.5rem;
}

.fb-activity-card {
  background: var(--bg-card);
  border: 1px solid var(--border-light);
  border-radius: 8px;
  padding: 1.6rem;
  display: flex;
  flex-direction: column;
  justify-content: space-between;
  box-shadow: var(--shadow-sm);
  transition: all var(--transition-normal);
  text-decoration: none;
}

.fb-activity-card:hover {
  transform: translateY(-3px);
  border-color: #1877F2;
  box-shadow: var(--shadow-md);
}

.fb-act-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  margin-bottom: 0.85rem;
  font-size: 0.75rem;
}

.fb-act-category {
  font-weight: 700;
  color: var(--accent-crimson);
  text-transform: uppercase;
  letter-spacing: 0.05em;
}

[data-theme="dark"] .fb-act-category {
  color: var(--accent-gold);
}

.fb-act-date {
  color: var(--text-muted);
}

.fb-act-title {
  font-family: var(--font-serif);
  font-size: 1.15rem;
  font-weight: 600;
  line-height: 1.4;
  color: var(--text-main);
  margin-bottom: 0.65rem;
  transition: color var(--transition-fast);
}

.fb-activity-card:hover .fb-act-title {
  color: #1877F2;
}

.fb-act-summary {
  font-size: 0.88rem;
  color: var(--text-body);
  line-height: 1.55;
  margin-bottom: 1.25rem;
  flex-grow: 1;
}

.fb-act-footer {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding-top: 0.75rem;
  border-top: 1px dashed var(--border-light);
  font-size: 0.8rem;
}

.fb-act-location {
  color: var(--text-muted);
  display: inline-flex;
  align-items: center;
  gap: 0.35rem;
  max-width: 65%;
  white-space: nowrap;
  overflow: hidden;
  text-overflow: ellipsis;
}

.fb-act-action {
  color: #1877F2;
  font-weight: 600;
  display: inline-flex;
  align-items: center;
  gap: 0.25rem;
}

/* Facebook Card Highlights in Sidebar */
.fb-card-highlights {
  display: flex;
  flex-direction: column;
  gap: 0.65rem;
  margin-top: 0.85rem;
  margin-bottom: 1.25rem;
}

.fb-highlight-item {
  padding: 0.65rem 0.85rem;
  background: var(--bg-parchment);
  border: 1px solid var(--border-light);
  border-radius: 6px;
  text-decoration: none;
  display: block;
  transition: all var(--transition-fast);
}

.fb-highlight-item:hover {
  background: var(--bg-card);
  border-color: #1877F2;
  transform: translateX(3px);
}

.fb-highlight-title {
  font-size: 0.84rem;
  font-weight: 600;
  color: var(--text-main);
  line-height: 1.35;
  margin-bottom: 0.2rem;
}

.fb-highlight-meta {
  font-size: 0.72rem;
  color: var(--text-muted);
  display: flex;
  align-items: center;
  justify-content: space-between;
}