@charset "UTF-8";
/**
 * Full Skin — 002-english
 * Theme: Warm coral + sage teal
 * Primary: #f97316  Accent: #0d9488
 * Hero Archetype: warm-light
 * Font Heading: Nunito
 */

/* ═══ Reduced Motion ═══ */
@media (prefers-reduced-motion: reduce) {
  *, *::before, *::after {
    animation-duration: 0.01ms !important;
    animation-iteration-count: 1 !important;
    transition-duration: 0.01ms !important;
    scroll-behavior: auto !important;
  }
}

/* ═══ Base ═══ */
html { scroll-behavior: smooth; }

::selection        { background: #fed7aa; color: #7c2d12; }
::-moz-selection   { background: #fed7aa; color: #7c2d12; }

*:focus-visible {
  outline: 3px solid var(--site-primary);
  outline-offset: 2px;
  border-radius: var(--radius-sm);
}

/* ═══ Scrollbar ═══ */
::-webkit-scrollbar       { width: 8px; height: 8px; }
::-webkit-scrollbar-track { background: var(--site-primary-light); }
::-webkit-scrollbar-thumb {
  background: linear-gradient(180deg, var(--site-primary) 0%, var(--site-primary-hover) 100%);
  border-radius: var(--radius-full);
  border: 2px solid var(--site-primary-light);
}
::-webkit-scrollbar-thumb:hover { background: var(--site-primary-dark); }

/* ═══ Body Background ═══ */
body {
  background: linear-gradient(160deg, var(--site-primary-light) 0%, var(--site-background) 50%, var(--site-accent-light) 100%);
  background-attachment: fixed;
  color: var(--site-text);
}

/* ═══ Typography Base ═══ */
h1, h2, h3, h4, .logo {
  font-family: var(--font-heading);
  letter-spacing: -0.02em;
}

/* ═══ Entrance Animations ═══ */
@keyframes fadeInUp {
  from { opacity: 0; transform: translateY(20px); }
  to   { opacity: 1; transform: translateY(0);    }
}
@keyframes fadeIn {
  from { opacity: 0; }
  to   { opacity: 1; }
}
@keyframes slideUp {
  from { opacity: 0; transform: translateY(8px); }
  to   { opacity: 1; transform: translateY(0);   }
}
@keyframes slideIn {
  from { transform: scaleX(0); }
  to   { transform: scaleX(1); }
}
@keyframes scoreSlide {
  from { opacity: 0; transform: translateX(-20px); }
  to   { opacity: 1; transform: translateX(0);      }
}

.fade-in  { animation: fadeIn  300ms ease-out; }
.slide-up { animation: slideUp 300ms ease-out; }

/* ═══ Hero — Archetype: warm-light ═══ */
.hero {
  background: linear-gradient(135deg, #fff7ed 0%, #ffffff 55%, #f0fdfa 100%);
  border-bottom: 2px solid var(--site-primary-border);
  padding: 5rem 2rem 4rem;
  text-align: center;
  position: relative;
  overflow: hidden;
  animation: fadeInUp 0.6s ease-out;
}

/* Decorative radial glow behind hero */
.hero::before {
  content: '';
  position: absolute;
  top: -40%;
  right: -10%;
  width: 480px;
  height: 480px;
  background: radial-gradient(circle, rgba(249,115,22,0.12) 0%, transparent 65%);
  border-radius: 50%;
  pointer-events: none;
}
.hero::after {
  content: '';
  position: absolute;
  bottom: -30%;
  left: -5%;
  width: 360px;
  height: 360px;
  background: radial-gradient(circle, rgba(13,148,136,0.08) 0%, transparent 65%);
  border-radius: 50%;
  pointer-events: none;
}

.hero h1 {
  font-size: clamp(2rem, 5vw, 3rem);
  font-weight: 800;
  color: var(--site-primary-dark);
  line-height: 1.2;
  font-family: var(--font-heading);
  letter-spacing: -0.025em;
  font-feature-settings: 'kern' 1;
  position: relative;
  z-index: 1;
}

.hero .subtitle, .hero .hero-subtitle {
  font-size: 1.15rem;
  color: var(--site-text-muted);
  margin-top: 0.75rem;
  max-width: 580px;
  margin-left: auto;
  margin-right: auto;
  line-height: 1.6;
  position: relative;
  z-index: 1;
}

/* Hero stats */
.hero-stats {
  display: flex;
  justify-content: center;
  gap: 3rem;
  margin-top: 2.5rem;
  flex-wrap: wrap;
  position: relative;
  z-index: 1;
}

.stat-item {
  text-align: center;
  padding: 1.25rem 1.75rem;
  background: linear-gradient(135deg, #ffffff 0%, var(--site-primary-light) 100%);
  border: 1.5px solid var(--site-primary-border);
  border-radius: var(--radius-md);
  min-width: 120px;
  transition: var(--transition-base);
}
.stat-item:hover {
  transform: translateY(-2px);
  box-shadow: var(--shadow-md);
}

.stat-number {
  display: block;
  font-size: 1.75rem;
  font-weight: 800;
  color: var(--site-primary-dark);
  font-family: var(--font-heading);
  font-variant-numeric: tabular-nums;
  letter-spacing: -0.02em;
}
.stat-label {
  display: block;
  font-size: 0.82rem;
  color: var(--site-text-muted);
  margin-top: 0.25rem;
  font-weight: 600;
  letter-spacing: 0.02em;
}

/* ═══ Page Header (detail/list pages) ═══ */
.page-header {
  background: linear-gradient(135deg, var(--site-primary-dark) 0%, var(--site-primary-hover) 100%);
  border-radius: 16px 16px 0 0;
  padding: 1.75rem 2rem 1.25rem;
}
.page-header h1 {
  font-size: clamp(1.4rem, 3vw, 2rem);
  font-weight: 800;
  color: #ffffff;
  line-height: 1.25;
  font-family: var(--font-heading);
}
.page-header .subtitle {
  color: #fed7aa;
  font-size: 1rem;
  margin-top: 0.4rem;
}
.page-header .breadcrumb {
  background: rgba(249,115,22,0.15);
  border-color: rgba(249,115,22,0.28);
}
.page-header .breadcrumb a          { color: #fdba74; }
.page-header .breadcrumb li:last-child { color: #ffffff; }

/* ═══ Breadcrumb ═══ */
.breadcrumb {
  background: var(--site-primary-light);
  border: 1px solid var(--site-primary-border);
  border-radius: var(--radius-button);
}
.breadcrumb ol {
  display: flex;
  flex-wrap: wrap;
  gap: 0.25rem;
  list-style: none;
  padding: 0;
  margin: 0;
  font-size: 0.875rem;
  color: var(--site-text-muted);
}
.breadcrumb a {
  color: var(--site-primary);
  text-decoration: none;
  transition: color 120ms ease;
}
.breadcrumb a:hover                 { color: var(--site-primary-dark); text-decoration: underline; }
.breadcrumb li:not(:last-child)::after {
  content: '›';
  color: var(--site-border-dark);
  font-weight: 700;
  margin-left: 0.25rem;
}
.breadcrumb li:last-child           { color: var(--site-text); font-weight: 600; }

/* ═══ Site Header ═══ */
.site-header {
  background: var(--glass-bg);
  backdrop-filter: blur(var(--glass-blur));
  -webkit-backdrop-filter: blur(var(--glass-blur));
  border-bottom: 1px solid var(--glass-border);
  box-shadow: var(--shadow-sm);
}
.logo .site-name { color: var(--site-text); }
.logo:hover .site-name { color: var(--site-primary); }
.main-nav a { color: var(--site-text-light); }
.main-nav a:hover { color: var(--site-primary); }
.main-nav a::after { background: var(--site-primary); }

/* ═══ Set Switcher ═══ */
.set-switcher {
  background: #ffffff;
  border: 1.5px solid var(--site-primary-border);
  border-radius: var(--radius-lg);
  box-shadow: var(--shadow-sm);
}
.set-switcher-label {
  font-size: 1rem;
  font-weight: 700;
  color: var(--site-text);
}
.set-btn {
  background: #ffffff;
  border: 2px solid var(--site-primary-border);
  border-radius: var(--radius-button);
  color: var(--site-text);
  font-size: 1rem;
  font-weight: 700;
  cursor: pointer;
  transition: var(--transition-base);
  position: relative;
}
.set-btn:hover {
  border-color: var(--site-primary);
  color: var(--site-primary);
  transform: translateY(-2px);
  box-shadow: var(--shadow-sm);
}
.set-btn.active {
  background: var(--site-primary);
  color: #ffffff;
  border-color: var(--site-primary-hover);
  box-shadow: 0 4px 12px var(--site-primary-glow);
}
/* Active tab slide indicator */
.set-btn.active::after {
  content: '';
  position: absolute;
  bottom: -2px;
  left: 20%;
  right: 20%;
  height: 3px;
  background: var(--site-primary-dark);
  border-radius: var(--radius-full);
  animation: slideIn 200ms ease-out;
}

/* ═══ Buttons ═══ */
.btn {
  font-size: 1rem;
  font-weight: 700;
  cursor: pointer;
  border: 2px solid transparent;
  border-radius: var(--radius-button);
  background: #ffffff;
  color: var(--site-text);
  box-shadow: var(--shadow-sm);
  transition: var(--transition-base);
  letter-spacing: 0.01em;
  position: relative;
  overflow: hidden;
  min-height: 44px;
}
.btn:hover {
  box-shadow: 0 4px 12px rgba(249,115,22,0.22);
  transform: translateY(-2px);
}
.btn:active {
  transform: translateY(0) scale(0.97);
  box-shadow: inset 0 2px 4px rgba(0,0,0,0.12);
}
.btn:focus-visible { outline: 3px solid var(--site-primary); outline-offset: 3px; }

.btn-primary, .btn-print {
  background: linear-gradient(135deg, var(--site-primary) 0%, var(--site-primary-hover) 100%);
  color: #ffffff;
  border-color: var(--site-primary-dark);
}
.btn-primary:hover, .btn-print:hover {
  background: linear-gradient(135deg, var(--site-primary-hover) 0%, var(--site-primary-dark) 100%);
  box-shadow: 0 8px 20px var(--site-primary-glow);
}

.btn-success, .btn-answers {
  background: linear-gradient(135deg, var(--site-accent) 0%, var(--site-accent-hover) 100%);
  color: #ffffff;
  border-color: var(--site-accent-dark);
}
.btn-success:hover, .btn-answers:hover {
  background: linear-gradient(135deg, var(--site-accent-hover) 0%, var(--site-accent-dark) 100%);
  box-shadow: 0 8px 20px rgba(13,148,136,0.28);
}

.btn-check {
  background: linear-gradient(135deg, #f59e0b 0%, #d97706 100%);
  color: #ffffff;
  border-color: #b45309;
}
.btn-check:hover {
  background: linear-gradient(135deg, #d97706 0%, #b45309 100%);
}

.btn-pdf {
  background: linear-gradient(135deg, var(--site-secondary) 0%, #be123c 100%);
  color: #ffffff;
}
.btn-pdf:hover {
  box-shadow: 0 8px 20px rgba(239,68,68,0.28);
}

/* Touch targets */
.btn, .set-btn, .btn-nav, .worksheet-card, .breadcrumb a {
  min-height: 44px;
}
.set-btn, .btn-nav {
  min-width: 44px;
  display: inline-flex;
  align-items: center;
  justify-content: center;
}

/* ═══ Intro Section ═══ */
.intro, .intro-section {
  background: linear-gradient(135deg, var(--site-primary-light) 0%, #fef9f0 100%);
  border: 1.5px solid var(--site-primary-border);
  border-radius: var(--radius-card);
}
.intro h3, .intro-section h3 { font-weight: 700; color: var(--site-primary-dark); }
.intro p, .intro-section p   { color: var(--site-text-muted); line-height: 1.7; }
.intro strong, .intro-section strong { color: var(--site-primary-dark); }

/* ═══ Body Content / Worksheet ═══ */
.body-content {
  background: #ffffff;
  border-radius: 0 0 var(--radius-card) var(--radius-card);
  border: 1.5px solid var(--site-primary-border);
  border-top: none;
}
.problems-grid { border-top: 2px solid var(--site-primary-border); }
.problem {
  border-bottom: 1px solid var(--site-border);
  font-size: 1.125rem;
  color: var(--site-text);
  transition: transform 180ms ease, box-shadow 180ms ease;
}
.problem:hover { transform: translateX(2px); }

/* Problem number badge */
.problem .num {
  background: var(--site-primary-light);
  color: var(--site-primary-dark);
  font-weight: 700;
  font-family: var(--font-heading);
}

/* Answer badge */
.problem .answer {
  background: var(--site-accent-light);
  color: var(--site-accent-dark);
  font-weight: 700;
  border-radius: var(--radius-button);
}

/* ═══ Variant Chip ═══ */
.variant-chip {
  font-size: 0.8rem;
  font-weight: 700;
  padding: 0.25rem 0.65rem;
  border-radius: var(--radius-full);
  color: var(--site-primary-dark);
  background: var(--site-primary-light);
  border: 1px solid var(--site-primary-border);
}

/* ═══ Interactive Answer Input ═══ */
.answer-input {
  border: 2px solid var(--site-primary-border);
  border-radius: var(--radius-button);
  background: #ffffff;
  color: var(--site-text);
  font-family: inherit;
  font-size: 1rem;
  font-weight: 600;
  transition: border-color 150ms ease, box-shadow 150ms ease;
}
.answer-input:focus {
  border-color: var(--site-primary);
  box-shadow: 0 0 0 3px rgba(249,115,22,0.16);
  outline: none;
}

/* Problem states */
.problem.is-correct .answer-input { border-color: #22c55e; background: #f0fdf4; color: #15803d; }
.problem.is-wrong   .answer-input { border-color: #ef4444; background: #fef2f2; color: #991b1b; }
.problem.is-empty   .answer-input { border-color: #f59e0b; background: #fffbeb; }
.problem.is-correct { border-left-color: #22c55e !important; }
.problem.is-wrong   { border-left-color: #ef4444 !important; }

/* ═══ Section Header ═══ */
.section-header {
  position: relative;
  padding-bottom: 1rem;
  margin-bottom: 1.75rem;
}
.section-header::after {
  content: '';
  position: absolute;
  bottom: 0;
  left: 0;
  width: 56px;
  height: 3px;
  background: linear-gradient(90deg, var(--site-primary), var(--site-accent));
  border-radius: var(--radius-full);
}
.section-header h2  { font-size: 1.5rem; font-weight: 800; color: var(--site-text); font-family: var(--font-heading); }
.section-header p   { color: var(--site-text-muted); margin-top: 0.25rem; }

/* ═══ Category Cards ═══ */
.categories-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(280px, 1fr));
  gap: 1.25rem;
}
.category-card {
  display: block;
  padding: 2rem;
  background: #ffffff;
  border: 1.5px solid var(--site-border);
  border-radius: var(--radius-card);
  text-decoration: none;
  color: inherit;
  position: relative;
  overflow: hidden;
  box-shadow: var(--shadow-sm);
  transition: transform 200ms cubic-bezier(0.4,0,0.2,1),
              box-shadow 200ms cubic-bezier(0.4,0,0.2,1),
              border-color 200ms cubic-bezier(0.4,0,0.2,1);
  animation: fadeInUp 0.5s ease-out backwards;
}
.category-card:nth-child(1) { animation-delay: 0.05s; }
.category-card:nth-child(2) { animation-delay: 0.10s; }
.category-card:nth-child(3) { animation-delay: 0.15s; }
.category-card:nth-child(4) { animation-delay: 0.20s; }
.category-card:nth-child(5) { animation-delay: 0.25s; }
.category-card:nth-child(6) { animation-delay: 0.30s; }

/* Top accent bar reveal on hover */
.category-card::before {
  background: linear-gradient(90deg, var(--site-primary), var(--site-accent));
}
/* Bottom accent line on hover */
.category-card::after {
  content: '';
  position: absolute;
  bottom: 0;
  left: 0;
  right: 0;
  height: 3px;
  background: linear-gradient(90deg, var(--site-primary), var(--site-accent));
  transform: scaleX(0);
  transition: transform 0.3s ease;
}
.category-card:hover {
  border-color: var(--site-primary-border);
  box-shadow: 0 12px 28px rgba(249,115,22,0.12), 0 4px 8px rgba(0,0,0,0.06);
  transform: translateY(-3px);
}
.category-card:hover::after { transform: scaleX(1); }

.category-icon   { font-size: 2.5rem; line-height: 1; margin-bottom: 1.25rem; display: block; }
.category-card h3 {
  font-weight: 800;
  font-size: 1.15rem;
  color: var(--site-text);
  margin: 0 0 0.5rem;
  font-family: var(--font-heading);
}
.category-card p  { font-size: 0.875rem; color: var(--site-text-muted); line-height: 1.5; margin: 0 0 1.25rem; }
.category-meta    { font-size: 0.875rem; font-weight: 700; color: var(--site-primary); margin-top: auto; display: flex; align-items: center; gap: 0.375rem; }

/* ═══ Subcategory Cards ═══ */
.subcategories-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(300px, 1fr));
  gap: 1.25rem;
}
.subcategory-card {
  display: block;
  padding: 1.75rem;
  background: #ffffff;
  border: 1.5px solid var(--site-border);
  border-left: 4px solid var(--site-primary);
  border-radius: var(--radius-card);
  text-decoration: none;
  color: inherit;
  position: relative;
  overflow: hidden;
  transition: var(--transition-base);
}
.subcategory-card:hover {
  border-left-color: var(--site-accent);
  box-shadow: var(--shadow-md);
  transform: translateY(-2px);
}
/* Bottom reveal */
.subcategory-card::after {
  content: '';
  position: absolute;
  bottom: 0;
  left: 0;
  right: 0;
  height: 3px;
  background: linear-gradient(90deg, var(--site-primary), var(--site-accent));
  transform: scaleX(0);
  transition: transform 0.3s ease;
}
.subcategory-card:hover::after { transform: scaleX(1); }
.subcategory-card h3    { font-weight: 800; color: var(--site-text); font-family: var(--font-heading); margin: 0 0 0.5rem; }
.subcategory-card p     { font-size: 0.875rem; color: var(--site-text-muted); margin: 0 0 1.25rem; }
.subcategory-arrow      { font-size: 0.875rem; font-weight: 700; color: var(--site-primary); margin-top: auto; display: flex; align-items: center; gap: 0.375rem; }
.subcategory-card:hover .subcategory-arrow { color: var(--site-accent); gap: 0.625rem; }

/* ═══ Worksheet Grid Cards ═══ */
.worksheets-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(260px, 1fr));
  gap: 1rem;
}
.worksheet-card {
  display: flex;
  flex-direction: column;
  padding: 1.25rem;
  background: #ffffff;
  border: 1px solid var(--site-border);
  border-bottom: 3px solid var(--site-primary);
  border-radius: var(--radius-card);
  text-decoration: none;
  color: inherit;
  transition: all 0.25s cubic-bezier(0.4,0,0.2,1);
}
.worksheet-card:hover {
  border-bottom-color: var(--site-accent);
  background: var(--site-primary-light);
  transform: translateY(-2px);
  box-shadow: 0 8px 20px rgba(249,115,22,0.12);
}
.worksheet-number {
  font-weight: 800;
  font-size: 1.3rem;
  color: var(--site-primary-dark);
  width: 2.4rem;
  height: 2.4rem;
  display: flex;
  align-items: center;
  justify-content: center;
  background: var(--site-primary-light);
  border: 1.5px solid var(--site-primary-border);
  border-radius: 50%;
  margin-bottom: 0.5rem;
  transition: transform 150ms cubic-bezier(0.34,1.56,0.64,1);
}
.worksheet-card:hover .worksheet-number {
  transform: scale(1.1);
  background: var(--site-primary);
  color: #ffffff;
  border-color: var(--site-primary-dark);
}
.worksheet-card h3      { font-size: 0.875rem; margin: 0; font-weight: 700; color: var(--site-text); }
.worksheet-problems     { font-size: 0.8rem; color: var(--site-text-muted); margin-top: 0.25rem; }

/* ═══ Content Toggle (Collapsible SEO) ═══ */
.body-content--collapsible {
  border: 1.5px solid var(--site-primary-border);
  border-radius: var(--radius-card);
  overflow: hidden;
}
.content-toggle { border: none; }
.content-toggle summary {
  padding: 0.9rem 1.25rem;
  font-weight: 700;
  font-size: 0.95rem;
  color: var(--site-primary-dark);
  cursor: pointer;
  background: var(--site-primary-light);
  border-bottom: 1px solid transparent;
  transition: background 150ms ease;
  list-style: none;
  display: flex;
  align-items: center;
  justify-content: space-between;
}
.content-toggle summary::-webkit-details-marker { display: none; }
.content-toggle summary::after {
  content: '⌄';
  font-size: 1.2rem;
  font-weight: 800;
  color: var(--site-primary);
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 1.5rem;
  height: 1.5rem;
  background: #ffffff;
  border-radius: 50%;
  transition: transform 200ms ease;
}
.content-toggle[open] summary::after  { transform: rotate(180deg); }
.content-toggle summary:hover         { background: #fef3e2; }
.content-toggle[open] summary         { border-bottom-color: var(--site-primary-border); }
.content-toggle-panel                 { padding: 1.25rem 1.5rem; }
.content-toggle-panel h2 { font-size: 1.25rem; font-weight: 800; color: var(--site-primary-dark); margin: 1rem 0 0.5rem; font-family: var(--font-heading); }
.content-toggle-panel h3 { font-size: 1.05rem; font-weight: 700; color: var(--site-primary-hover); margin: 0.75rem 0 0.4rem; }
.content-toggle-panel p  { line-height: 1.7; color: var(--site-text-muted); margin: 0.4rem 0; }
.content-toggle-panel ul,
.content-toggle-panel ol { padding-left: 1.25rem; margin: 0.5rem 0; color: var(--site-text-muted); }
.content-toggle-panel li { margin: 0.3rem 0; line-height: 1.6; }
.content-toggle-panel strong { color: var(--site-primary-dark); }

/* ═══ Score Panel ═══ */
.score-panel {
  background: #ffffff;
  border: 1.5px solid var(--site-primary-border);
  border-radius: var(--radius-card);
  padding: 1.25rem 1.5rem;
  margin-bottom: 1.5rem;
  transition: all 200ms ease;
}
.score-panel.score-visible { animation: scoreSlide 300ms ease-out; }
.score-inner { position: relative; }
.score-inner::after {
  content: '';
  display: block;
  height: 5px;
  margin-top: 0.75rem;
  background: linear-gradient(90deg, var(--site-primary-light), var(--site-accent-light));
  border: 1px solid var(--site-primary-border);
  border-radius: var(--radius-full);
}
.score-icon   { font-size: 1.5rem; line-height: 1; }
.score-detail { font-size: 1rem; font-weight: 700; color: var(--site-text); }
.score-pct    { font-size: 1.6rem; font-weight: 800; color: var(--site-primary); font-family: var(--font-heading); }

/* Score staggered reveal */
.score-panel.score-visible .score-icon   { animation: fadeIn 200ms ease-out 0ms   both; }
.score-panel.score-visible .score-detail { animation: fadeIn 200ms ease-out 80ms  both; }
.score-panel.score-visible .score-pct    { animation: fadeIn 250ms ease-out 160ms both; }

.score-retry {
  background: var(--site-primary-light);
  color: var(--site-primary-dark);
  border: 2px solid var(--site-primary-border);
  cursor: pointer;
  transition: var(--transition-base);
}
.score-retry:hover {
  background: var(--site-primary);
  color: #ffffff;
  border-color: var(--site-primary-dark);
}

/* ═══ Content Section ═══ */
.content-section { padding: 1.5rem; margin: 1rem 0; }
.content-section h2 { font-family: var(--font-heading); color: var(--site-primary-dark); font-weight: 800; margin-bottom: 0.75rem; }
.content-section h3 { color: var(--site-primary-hover); font-weight: 700; }
.content-section p  { line-height: 1.7; color: var(--site-text-muted); }

/* ═══ SEO Components ═══ */
.seo-components     { margin: 1.5rem 0; }
.seo-components--primary { display: grid; grid-template-columns: repeat(auto-fit, minmax(280px, 1fr)); gap: 1.4rem; }
.seo-components--secondary { margin-top: 1rem; }
.seo-more-grid      { display: grid; grid-template-columns: repeat(auto-fit, minmax(260px, 1fr)); gap: 1.4rem; }

.seo-block {
  background: #ffffff;
  border: 1px solid var(--site-primary-border);
  border-radius: var(--radius-card);
  padding: 1.25rem 1.5rem;
  box-shadow: var(--shadow-sm);
  transition: box-shadow 200ms ease, transform 200ms ease;
}
.seo-block:hover {
  transform: translateY(-2px);
  box-shadow: var(--shadow-md);
  border-color: var(--site-primary);
}
.seo-components--secondary .seo-block { background: var(--site-primary-light); }

/* Primary cards: orange top bar */
.seo-card { border-top: 4px solid var(--site-primary); }

/* Accent variants */
.seo-card.benefits,
.seo-card.steps,
.seo-card.tutorial,
.seo-card.resources { border-top-color: var(--site-accent); }

/* Secondary left bars — alternating orange / teal */
.seo-block.tutorial        { border-left: 3px solid var(--site-primary); }
.seo-block.examples        { border-left: 3px solid var(--site-accent); }
.seo-block.use-cases       { border-left: 3px solid var(--site-primary); }
.seo-block.common-mistakes { border-left: 3px solid var(--site-accent); }
.seo-block.practice        { border-left: 3px solid var(--site-primary); }
.seo-block.requirements    { border-left: 3px solid var(--site-accent); }
.seo-block.resources       { border-left: 3px solid var(--site-primary); }
.seo-block.next-steps      { border-left: 3px solid var(--site-accent); }
.seo-block.summary         { border-left: 3px solid var(--site-primary); }
.seo-block.related         { border-left: 3px solid var(--site-accent); }

/* SEO block typography */
.seo-block h2  { font-size: 1.1rem; font-weight: 800; color: var(--site-primary-dark); margin: 0 0 0.6rem; font-family: var(--font-heading); }
.seo-block h3  { font-size: 1rem; font-weight: 700; color: var(--site-primary-hover); margin: 0.6rem 0 0.4rem; }
.seo-block h4  { font-size: 0.9rem; font-weight: 700; color: var(--site-text-light); margin: 0.5rem 0 0.3rem; }
.seo-block p   { font-size: 0.9rem; line-height: 1.65; color: var(--site-text-muted); margin: 0.35rem 0; }
.seo-block ul, .seo-block ol { padding-left: 1.2rem; margin: 0.4rem 0; }
.seo-block li  { font-size: 0.9rem; line-height: 1.55; color: var(--site-text-muted); margin: 0.25rem 0; }
.seo-block strong { color: var(--site-primary-dark); }
.seo-block a   { color: var(--site-primary); text-decoration: none; }
.seo-block a:hover { text-decoration: underline; color: var(--site-primary-dark); }

/* SEO FAQ details */
.seo-block details { border-bottom: 1px solid var(--site-primary-border); padding: 0.5rem 0; }
.seo-block details:last-child { border-bottom: none; }
.seo-block details summary { font-weight: 700; font-size: 0.92rem; cursor: pointer; list-style: none; color: var(--site-primary-hover); }
.seo-block details summary::-webkit-details-marker { display: none; }
.seo-block details summary::before { content: "▸"; margin-right: 0.4rem; color: var(--site-primary); display: inline-block; transition: transform 150ms ease; }
.seo-block details[open] summary::before { transform: rotate(90deg); }
.seo-block details p { padding: 0.3rem 0 0.3rem 1rem; color: var(--site-text-muted); font-size: 0.88rem; }

/* ═══ Page Header Section (homepage/list page hero) ═══ */
.page-header-section {
  background: linear-gradient(135deg, var(--site-primary) 0%, var(--site-primary-dark) 100%);
  color: #ffffff;
  border-radius: var(--radius-lg);
  overflow: hidden;
}
.page-header-section h1 { text-shadow: 0 2px 10px rgba(0,0,0,0.1); }
.page-header-section .subtitle { opacity: 0.9; }

/* ═══ Page Navigation ═══ */
.page-navigation {
  background: rgba(255,255,255,0.92);
  backdrop-filter: blur(8px);
  border: 1.5px solid var(--site-primary-border);
  border-radius: var(--radius-card);
  box-shadow: var(--shadow-sm);
}
.btn-nav {
  color: var(--site-primary);
  border: 2px solid var(--site-primary-border);
  border-radius: var(--radius-button);
  font-weight: 700;
  text-decoration: none;
  transition: var(--transition-base);
  background: #ffffff;
}
.btn-nav:hover {
  background: var(--site-primary);
  color: #ffffff;
  border-color: var(--site-primary-dark);
  transform: translateY(-2px);
  box-shadow: 0 6px 16px var(--site-primary-glow);
}
.btn-nav.disabled { color: var(--site-border-dark); cursor: not-allowed; }
.btn-nav.back-to-list { background: var(--site-primary); color: #ffffff; border-color: var(--site-primary-dark); }

/* ═══ Vocabulary / Word Items (site.css component skins) ═══ */
.vocab-item {
  background: var(--site-primary-light);
  border-color: var(--site-primary-border);
}
.vocab-item:hover { background: #ffffff; border-color: var(--site-primary); box-shadow: var(--shadow-md); }
.vocab-item .num  { background: var(--site-primary-light); color: var(--site-primary-dark); }

.spelling-item { background: var(--site-primary-light); }
.spelling-item:hover { background: #ffffff; border-color: var(--site-accent); }
.spelling-item .scrambled {
  color: var(--site-accent-dark);
  border-color: var(--site-accent);
  font-family: 'Courier New', monospace;
}
.spelling-item .blank  { border-bottom-color: var(--site-primary); }
.spelling-item .answer { background: var(--site-accent-light); color: var(--site-accent-dark); }

.word-list-item { background: var(--site-primary-light); border-color: transparent; }
.word-list-item:hover { background: #ffffff; border-color: var(--site-primary); box-shadow: var(--shadow-sm); }
.word-list-item .num   { color: var(--site-primary-dark); }
.word-list-item .word  { color: var(--site-text); }
.word-list-item .length {
  background: var(--site-primary-border);
  color: var(--site-text-muted);
  font-size: 0.75rem;
  padding: 0.2rem 0.6rem;
  border-radius: var(--radius-full);
  font-weight: 700;
}

.fill-blank-item { background: var(--site-primary-light); }
.fill-blank-item:hover { background: #ffffff; border-color: var(--site-accent); }
.fill-blank-item .num { color: var(--site-primary); }
.fill-blank-item .blanked .blank-char { color: var(--site-accent); }
.fill-blank-item .answer { background: var(--site-accent); color: #ffffff; }

.matching-item { background: var(--site-primary-light); border-color: var(--site-border); }
.matching-item:hover { border-color: var(--site-primary); background: #ffffff; box-shadow: var(--shadow-sm); }
.matching-item .num { background: var(--site-primary); color: #ffffff; }

/* Flashcard */
.flashcard {
  border-color: var(--site-primary);
  background: #ffffff;
}
.flashcard:hover {
  border-color: var(--site-accent);
  box-shadow: var(--shadow-premium);
}
.flashcard::before { background: var(--site-primary); }
.flashcard .front  { color: var(--site-text); }
.flashcard .back   { color: var(--site-primary); border-top-color: var(--site-primary-border); }

/* Tracing */
.tracing-item { background: var(--site-primary-light); border-color: var(--site-primary-border); }
.tracing-item .word-display { color: var(--site-primary-dark); }
.tracing-item .dotted { color: var(--site-text-muted); }

/* Bingo */
.bingo-header-cell { background: var(--site-primary); color: #ffffff; }
.bingo-grid        { background: var(--site-primary-dark); }
.bingo-cell { background: #ffffff; border-color: var(--site-primary-border); color: var(--site-text); }
.bingo-cell:hover  { box-shadow: var(--shadow-md); }
.bingo-cell.free   { background: var(--site-accent); color: #ffffff; }

/* ═══ Worksheet Content ═══ */
.worksheet-content {
  background: #ffffff;
  border-color: var(--site-primary-border);
  box-shadow: var(--shadow-md);
}
.worksheet-title { color: var(--site-text); border-bottom-color: var(--site-primary-border); }

/* ═══ List Page ═══ */
.list-page .category-list li a {
  background: #ffffff;
  border-color: var(--site-primary-border);
  box-shadow: var(--shadow-sm);
}
.list-page .category-list li a:hover { border-color: var(--site-primary); box-shadow: var(--shadow-lg); }
.list-page .category-list .name { color: var(--site-text); }
.list-page .category-list .description { color: var(--site-text-muted); }
.list-page .worksheet-card {
  background: #ffffff;
  border-color: var(--site-primary-border);
  box-shadow: var(--shadow-sm);
}
.list-page .worksheet-card:hover { border-color: var(--site-primary); box-shadow: var(--shadow-lg); }
.list-page .worksheet-card .set-number  { color: var(--site-primary-dark); }
.list-page .worksheet-card .set-description { color: var(--site-text-muted); }
.list-page .worksheet-card .card-icon { color: var(--site-primary); }

/* ═══ Homepage Category Grid ═══ */
.homepage .categories h2 { color: var(--site-text); }
.homepage .category-grid li a {
  background: #ffffff;
  border-color: var(--site-border);
  box-shadow: 0 4px 16px rgba(0,0,0,0.04);
}
.homepage .category-grid li a:hover {
  border-color: var(--site-primary);
  box-shadow: 0 16px 40px rgba(249,115,22,0.12);
}
.homepage .category-grid .name        { color: var(--site-text); }
.homepage .category-grid li a:hover .name { color: var(--site-primary-dark); }
.homepage .category-grid .description { color: var(--site-text-muted); }
.go-arrow { color: var(--site-primary); }

/* ═══ Site Footer ═══ */
.site-footer {
  background: var(--site-surface);
  border-top: 1px solid var(--site-primary-border);
  color: var(--site-text-muted);
}
.site-footer nav a { color: var(--site-text-muted); }
.site-footer nav a:hover { color: var(--site-primary); }

/* ═══ Responsive ═══ */
@media (max-width: 768px) {
  .hero h1      { font-size: clamp(1.5rem, 6vw, 2rem); }
  .hero-stats   { gap: 1.5rem; }
  .stat-number  { font-size: 1.4rem; }
  .hero::before, .hero::after { display: none; }
  .categories-grid  { grid-template-columns: repeat(auto-fill, minmax(160px, 1fr)); }
  .subcategories-grid { grid-template-columns: 1fr; }
  .worksheets-grid  { grid-template-columns: repeat(auto-fill, minmax(200px, 1fr)); }
  .seo-components--primary { grid-template-columns: 1fr; }
  .seo-more-grid    { grid-template-columns: 1fr; }
  .page-navigation  { flex-wrap: wrap; justify-content: center; }
  .homepage .category-grid { grid-template-columns: 1fr; }
}
@media (max-width: 480px) {
  .hero               { padding: 3rem 1rem 2rem; }
  .hero h1            { font-size: 1.5rem; }
  .hero-stats         { flex-direction: column; gap: 0.75rem; }
  .categories-grid    { grid-template-columns: 1fr; }
  .site-footer nav ul { flex-direction: column; gap: 1rem; }
}

/* ═══ Dark Mode ═══ */


/* ════════════════════════════════════════════════════ */
/* 🚀 ANTIGRAVITY ENGLISH LITERACY FRAMEWORK 🚀 */
/* ════════════════════════════════════════════════════ */

.antigravity-theme {
  --primary-glow: rgba(45, 212, 191, 0.2);
  --glass-bg: rgba(255, 255, 255, 0.7);
}

/* 1. Global Layout Width Pact */
.container,
.hero-ag-shell.container,
.ag-explore-section.container,
.ag-seo-content.container,
.ag-seo-blocks.container {
  max-width: var(--container-max) !important;
  margin-left: auto !important;
  margin-right: auto !important;
  width: 100% !important;
  box-sizing: border-box !important;
}

@media (min-width: 1200px) {
  .container {
    padding-left: 20px !important;
    padding-right: 20px !important;
  }
}

main.homepage.antigravity-theme {
  box-sizing: border-box !important;
}

/* 2. Floating Premium Hero Section */
.hero-ag {
  position: relative;
  overflow: hidden;
  margin: 1rem 0 2.5rem;
  padding: 3rem 0;
  border-radius: var(--detail-border-radius);
  background: var(--site-surface);
  border: 1px solid var(--site-border);
  box-shadow: var(--shadow-lg);
  max-width: none;
  width: 100%;
  display: flex;
  align-items: center;
  justify-content: center;
}

.hero-ag-bg {
  position: absolute;
  top: 0; left: 0; right: 0; bottom: 0;
  z-index: 0;
  overflow: hidden;
}

.glow-orb {
  position: absolute;
  border-radius: 50%;
  filter: blur(80px);
  opacity: 0.5;
}
.orb-1 { width: 500px; height: 500px; background: rgba(45, 212, 191, 0.15); top: -200px; right: -100px; }
.orb-2 { width: 400px; height: 400px; background: rgba(251, 113, 133, 0.1); bottom: -150px; left: -100px; }

.paper-grid {
  position: absolute; 
  top: 0; left: 0; right: 0; bottom: 0;
  opacity: 0.15;
}

.hero-ag-container {
  position: relative;
  z-index: 1;
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 3rem;
  align-items: center;
  width: 100%;
  padding: 0 32px;
  box-sizing: border-box;
}

.brand-eyebrow {
  display: inline-block;
  padding: 4px 12px;
  background: var(--site-primary-light);
  color: var(--site-primary-dark);
  font-size: 0.85rem;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 1.5px;
  border-radius: var(--radius-full);
  margin-bottom: 1rem;
  border: 1px solid var(--site-primary-border);
}

.hero-ag-title {
  font-size: clamp(2.5rem, 5vw, 3.5rem);
  font-weight: 800;
  color: var(--site-text);
  line-height: 1.15;
  margin-bottom: 1rem;
  font-family: var(--font-heading);
}

.hero-ag-subtitle {
  font-size: 1.125rem;
  color: var(--site-text-muted);
  line-height: 1.6;
  margin-bottom: 2rem;
  max-width: 500px;
}

/* Literacy Action Buttons */
.btn-ag-primary {
  display: inline-flex;
  align-items: center;
  gap: 0.5rem;
  background: var(--site-primary);
  color: #fff;
  padding: 0.875rem 2rem;
  border-radius: var(--radius-button);
  font-size: 1.125rem;
  font-weight: 700;
  text-decoration: none;
  transition: var(--transition-bounce);
  box-shadow: 0 4px 14px var(--primary-glow);
}
.btn-ag-primary:hover {
  transform: translateY(-2px);
  background: var(--site-primary-hover);
  box-shadow: 0 8px 24px var(--primary-glow);
}

/* Floating Sheets Illustration */
.hero-ag-visual {
  position: relative;
  height: 400px;
  display: flex;
  align-items: center;
  justify-content: center;
  perspective: 1000px;
}

.floating-sheets {
  position: relative;
  width: 100%;
  height: 100%;
  transform-style: preserve-3d;
}

.floating-sheets .sheet {
  position: absolute;
  background: var(--site-surface);
  border: 1px solid var(--site-border);
  border-radius: var(--radius-card);
  box-shadow: var(--shadow-premium);
  padding: 2rem;
  width: 280px;
  height: 320px;
  display: flex;
  flex-direction: column;
  justify-content: center;
  align-items: center;
  gap: 1.25rem;
  transition: transform 0.5s ease;
}

.sheet-1 {
  top: 10%; left: 30%;
  transform: rotate(-4deg) translateZ(20px);
  z-index: 2;
  border-left: 4px solid var(--site-primary);
}
.sheet-2 {
  top: 25%; left: 15%;
  transform: rotate(6deg) translateZ(-10px);
  opacity: 0.9;
  z-index: 1;
  background: var(--site-background);
  border-left: 4px solid var(--site-accent);
}
.sheet-badge {
  position: absolute;
  bottom: 20%; right: 10%;
  background: #fef08a;
  color: #854d0e;
  width: 60px; height: 60px;
  display: flex; align-items: center; justify-content: center;
  border-radius: 50%;
  font-weight: 800; font-size: 1.5rem;
  transform: rotate(12deg) translateZ(30px);
  box-shadow: var(--shadow-md);
  z-index: 3;
  border: 3px solid #fff;
  font-family: var(--font-number);
}

/* 3. Category & Explore System */
.ag-explore-section {
  padding: 2rem 0;
  margin: 0 auto;
}

.ag-section-header { text-align: center; margin-bottom: 3rem; }
.ag-section-title { font-size: 2.25rem; font-weight: 800; color: var(--site-text); font-family: var(--font-heading); margin-bottom: 0.5rem; }
.ag-section-subtitle { font-size: 1.125rem; color: var(--site-text-muted); }

.ag-level-group {
  margin-bottom: 3rem;
  padding: 2rem;
  background: var(--site-background);
  border-radius: var(--detail-border-radius);
  border: 1px solid var(--site-border);
}

.ag-level-header {
  display: flex;
  align-items: center;
  gap: 1rem;
  margin-bottom: 2rem;
  padding-bottom: 1rem;
  border-bottom: 1px solid var(--site-border-dark);
}
.ag-level-badge {
  font-size: 1.5rem;
  width: 44px; height: 44px;
  display: flex; align-items: center; justify-content: center;
  border-radius: var(--radius-button);
}
.ag-level-header h3 { font-size: 1.5rem; font-weight: 800; color: var(--site-text); font-family: var(--font-heading); }

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

/* Cards */
.ag-cat-card {
  background: var(--site-surface);
  border: 1px solid var(--site-border);
  border-radius: var(--radius-card);
  padding: 1.5rem;
  display: flex;
  flex-direction: column;
  gap: 1.5rem;
  text-decoration: none;
  transition: var(--transition-smooth);
  box-shadow: var(--shadow-sm);
  position: relative;
  overflow: hidden;
}

.ag-cat-card::before {
  content: '';
  position: absolute;
  top: 0; left: 0; right: 0;
  height: 4px;
  background: var(--site-primary);
  transform: scaleX(0);
  transform-origin: left;
  transition: transform 0.3s ease;
}

.ag-cat-card:hover {
  transform: translateY(-4px);
  box-shadow: var(--shadow-lg);
  border-color: var(--site-primary-border);
}
.ag-cat-card:hover::before { transform: scaleX(1); }

.ag-cat-header { display: flex; gap: 1rem; align-items: flex-start; }
.ag-cat-icon { font-size: 2.5rem; line-height: 1; }
.ag-cat-title-link { font-size: 1.25rem; font-weight: 700; color: var(--site-text); margin: 0 0 0.5rem; font-family: var(--font-heading); }
.ag-cat-card:hover .ag-cat-title-link { color: var(--site-primary-dark); }
.ag-cat-desc { font-size: 0.9rem; color: var(--site-text-muted); line-height: 1.5; margin: 0; }

.ag-subcat-pills { display: flex; flex-wrap: wrap; gap: 0.5rem; }
.ag-subcat-pill {
  font-size: 0.8rem;
  font-weight: 600;
  padding: 0.35rem 0.8rem;
  background: var(--site-background);
  color: var(--site-text-light);
  border-radius: var(--radius-full);
  border: 1px solid var(--site-border-dark);
  transition: var(--transition-base);
  text-decoration: none;
}
.ag-cat-card:hover .ag-subcat-pill {
  border-color: var(--site-primary-border);
  color: var(--site-primary-dark);
}
.pill-more { background: var(--site-primary-light); color: var(--site-primary-dark); border-color: transparent; }

/* 4. Elegant Editorial Breadcrumb */
.breadcrumb {
  background: transparent !important;
  border: none !important;
  padding: 0 0 1rem 0 !important;
  margin: 0 !important;
  box-shadow: none !important;
  width: 100%;
}
.breadcrumb ol {
  display: flex !important;
  flex-wrap: wrap !important;
  justify-content: flex-start !important;
  align-items: center !important;
  gap: 0.5rem !important;
  padding: 0 !important;
  margin: 0 !important;
  font-family: var(--font-body) !important;
  font-size: 0.95rem !important;
  font-weight: 500 !important;
  color: var(--site-text-light) !important;
  list-style: none !important;
}
.breadcrumb li { display: inline-flex; align-items: center; }
.breadcrumb li:not(:last-child)::after {
  content: '→'; color: var(--site-border-dark); margin-left: 0.5rem; font-weight: 400; font-size: 0.85rem;
}
.breadcrumb a { 
  color: var(--site-text-light) !important; 
  text-decoration: none !important; 
  background: transparent !important; 
  padding: 0 !important; 
  border-bottom: 1px solid transparent !important;
  transition: all 0.2s ease !important;
}
.breadcrumb a:hover { 
  color: var(--site-primary-dark) !important; 
  border-bottom-color: var(--site-primary-dark) !important;
}

/* 5. Detail Page & Platform Worksheets Engine Overrides */
.ag-page-header {
  margin: 2rem 0;
  padding: 1.5rem 0 2rem 0;
  background: transparent;
  border: none;
  border-bottom: 1px solid var(--site-border-dark);
  box-shadow: none;
}

.ag-detail-main .form-exercise-container {
  max-width: 100% !important; /* Force detail-atom engine to obey 1200px container */
}

#detail-atom-mount {
  background: transparent !important;
  border: none !important;
  box-shadow: none !important;
  margin: 0 !important;
  padding: 0 !important;
}

/* Toolbars */
.ag-detail-main .da-toolbar {
  background: transparent !important;
  border: none !important;
  border-radius: 0 !important;
  padding: 0 !important;
  box-shadow: none !important;
  margin-bottom: 2rem !important;
  display: flex;
  flex-wrap: wrap;
  gap: 1rem;
  align-items: center;
}

/* Absolute Light Theme Enforcer for problem cells */
.ag-detail-main .form-problem {
  background: var(--site-surface) !important;
  border: 1px solid var(--site-border) !important;
  box-shadow: var(--shadow-sm) !important;
  border-radius: var(--radius-card) !important;
  padding: 1.25rem 2rem !important;
  margin-bottom: 0 !important;
  transition: all var(--dur-fast) var(--transition-smooth) !important;
  display: flex !important;
  flex-direction: column !important;
  gap: 0.75rem !important;
}
.ag-detail-main .form-problem:hover {
  transform: translateY(-2px) !important;
  box-shadow: var(--shadow-md) !important;
  border-color: var(--site-primary-border) !important;
}
.ag-detail-main .form-problem .problem-text {
  color: var(--site-text) !important;
  font-family: var(--font-heading) !important;
  font-size: 1.1rem !important;
}
.ag-detail-main .form-problem .problem-number {
  background: var(--site-primary-light) !important;
  color: var(--site-primary-dark) !important;
  font-family: var(--font-number) !important;
  font-weight: 800 !important;
  border-radius: var(--radius-badge) !important;
  border: 1px solid var(--site-primary-border) !important;
  min-width: 2rem !important;
  height: 2rem !important;
  display: inline-flex !important;
  align-items: center !important;
  justify-content: center !important;
  padding: 0 0.5rem !important;
}
.ag-detail-main .form-problem .problem-input {
  border: 2px solid var(--site-border-dark) !important;
  background: var(--site-background) !important;
  color: var(--site-primary-dark) !important;
  font-family: var(--font-number) !important;
  font-weight: 800 !important;
  border-radius: 12px !important;
  box-shadow: inset 0 2px 4px rgba(0,0,0,0.02) !important;
  padding: 0.4rem !important;
  width: 5rem !important;
  text-align: center !important;
}
.ag-detail-main .form-problem .problem-input:focus {
  border-color: var(--site-primary) !important;
  background: var(--site-surface) !important;
  box-shadow: 0 0 0 3px var(--site-primary-light) !important;
  outline: none !important;
}
.ag-detail-main .form-problem.answered { 
  background: #f0fdf4 !important; 
  border-left: 4px solid var(--site-primary) !important; 
}
.ag-detail-main .form-problem.is-wrong { 
  border-left: 4px solid #f43f5e !important; 
}

/* Worksheet Grid Cards - Detail sets */
.ag-set-switcher-wrapper {
  background: var(--site-surface);
  border: 1px solid var(--site-border);
  border-radius: var(--radius-card);
  padding: 1.5rem;
  margin-top: 1rem;
}
.ag-set-switcher-label { font-weight: 700; color: var(--site-text); margin-right: 1rem; }
.ag-set-buttons { display: inline-flex; flex-wrap: wrap; gap: 0.5rem; }
.ag-set-btn { text-decoration: none; }
.ag-set-btn-inner {
  display: flex; align-items: center; justify-content: center;
  width: 36px; height: 36px;
  background: var(--site-background);
  color: var(--site-text);
  border: 1px solid var(--site-border-dark);
  border-radius: 50%;
  font-weight: 700; font-family: var(--font-number);
  transition: var(--transition-base);
}
.ag-set-btn:hover .ag-set-btn-inner { background: var(--site-primary-light); color: var(--site-primary-dark); border-color: var(--site-primary-border); transform: scale(1.1); }
.ag-set-btn.active .ag-set-btn-inner { background: var(--site-primary); color: #fff; border-color: var(--site-primary-dark); }

/* 6. Editorial Prose / Workbook Guide Typography */
.ag-prose {
  font-family: var(--font-body);
  color: var(--site-text);
  line-height: 1.75;
  max-width: 68ch; /* Optimal reading column width */
  margin: 0 auto;
  padding: 1rem 0;
}
.ag-prose > *:first-child { margin-top: 0; }
.ag-prose > *:last-child { margin-bottom: 0; }

.ag-prose h2, .ag-prose .markdown-h2 {
  font-family: var(--font-heading);
  font-size: 1.6rem;
  font-weight: 800;
  color: var(--site-primary-dark);
  margin: 2.5rem 0 1rem;
  padding-bottom: 0.5rem;
  border-bottom: 2px solid var(--site-primary-light);
}
.ag-prose h3, .ag-prose .markdown-h3 {
  font-family: var(--font-heading);
  font-size: 1.3rem;
  font-weight: 700;
  color: var(--site-text);
  margin: 2rem 0 0.8rem;
}
.ag-prose p {
  margin-bottom: 1.25rem;
  font-size: 1.05rem;
}
.ag-prose a {
  color: var(--site-primary-dark);
  text-decoration: underline;
  text-decoration-thickness: 2px;
  text-underline-offset: 4px;
  text-decoration-color: var(--site-primary-light);
  transition: all 0.2s ease;
}
.ag-prose a:hover {
  color: var(--site-primary);
  text-decoration-color: var(--site-primary);
}
.ag-prose strong {
  color: var(--site-primary-dark);
  font-weight: 800;
}
.ag-prose ul, .ag-prose ol {
  margin: 1.5rem 0 1.5rem 0.5rem;
  padding-left: 2rem;
}
.ag-prose li {
  margin-bottom: 0.5rem;
  font-size: 1.05rem;
}
.ag-prose li::marker { color: var(--site-primary); }

/* Beautiful Callouts & Learning Note Panels inside Prose */
.ag-prose blockquote, .ag-prose .callout {
  background: var(--site-primary-light);
  border-left: 4px solid var(--site-primary);
  padding: 1.5rem 1.5rem 1.5rem 2.5rem;
  margin: 2rem 0;
  border-radius: var(--radius-sm);
  color: var(--site-primary-dark);
  font-family: var(--font-heading);
  font-size: 1.15rem;
  position: relative;
}
.ag-prose blockquote::before {
  content: '💡';
  position: absolute;
  left: 0.75rem;
  top: 1.5rem;
  font-size: 1.2rem;
  font-style: normal;
}

/* 7. Header Brand Zone Upgrade (Literacy Print Studio Style) */
.site-header {
  border-bottom: 1px solid var(--site-border) !important;
  background: rgba(255, 255, 255, 0.95) !important;
  box-shadow: 0 4px 24px rgba(0, 0, 0, 0.02) !important;
  padding-top: 1rem !important;
  padding-bottom: 1rem !important;
}

/* Distinctive Branding for the logo and brand name */
.logo {
  display: flex !important;
  align-items: center !important;
  gap: 0.75rem !important;
  text-decoration: none !important;
}

.logo img {
  filter: drop-shadow(0 4px 6px rgba(15, 118, 110, 0.15)) !important;
  width: 44px !important;
  height: 44px !important;
}

.logo .site-name {
  font-family: var(--font-heading) !important;
  font-size: 1.55rem !important;
  font-weight: 800 !important;
  color: var(--site-primary-dark) !important;
  letter-spacing: -0.01em !important;
  transition: color 0.3s ease !important;
}

.logo:hover .site-name {
  color: var(--site-primary) !important;
}

@media (max-width: 1024px) {
  .hero-ag-container { grid-template-columns: 1fr; text-align: center; }
  .hero-ag-subtitle { margin-left: auto; margin-right: auto; }
  .hero-ag-visual { height: 300px; }
  .floating-sheets .sheet { width: 220px; height: 260px; }
  .sheet-1 { left: 15%; top: 5%; }
  .sheet-2 { left: 35%; top: 15%; }
}
@media (max-width: 640px) {
  .hero-ag-stats { flex-direction: column; gap: 1rem; }
}