@charset "UTF-8";

/* ========================================
   Global Aesthetics
   ======================================== */
body {
  background-color: var(--site-background);
  background-image:
    radial-gradient(at 0% 0%,     rgba(249, 115,  22, 0.08) 0px, transparent 50%),
    radial-gradient(at 100% 0%,   rgba( 13, 148, 136, 0.07) 0px, transparent 50%),
    radial-gradient(at 100% 100%, rgba(249, 115,  22, 0.05) 0px, transparent 50%),
    radial-gradient(at 0% 100%,   rgba( 13, 148, 136, 0.05) 0px, transparent 50%),
    url("data:image/svg+xml,%3Csvg width='60' height='60' viewBox='0 0 60 60' xmlns='http://www.w3.org/2000/svg'%3E%3Cg fill='none' fill-rule='evenodd'%3E%3Cg fill='%23f97316' fill-opacity='0.025'%3E%3Cpath d='M36 34v-4h-2v4h-4v2h4v4h2v-4h4v-2h-4zM6 34v-4H4v4H0v2h4v4h2v-4h4v-2H6zM6 4v-4H4v4H0v2h4v4h2v-4h4v-2H6zm30 0v-4h-2v4h-4v2h4v4h2v-4h4v-2h-4z'/%3E%3C/g%3E%3C/g%3E%3C/svg%3E");
  background-attachment: fixed;
  color: var(--site-text);
  font-family: var(--font-body);
  line-height: 1.6;
}

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

.homepage,
.list-page,
.detail-page {
  max-width: 1200px !important;
  margin: 0 auto !important;
  padding: 2rem 1.5rem;
}

.content,
.body-content,
.seo-block {
  background: white !important;
  padding: 4rem !important;
  border-radius: var(--radius-lg) !important;
  box-shadow: var(--shadow-md) !important;
  margin: 4rem 0 !important;
  border: 1px solid var(--site-border-light) !important;
  line-height: 1.8;
  position: relative;
}

.content h2,
.body-content h2 {
  font-size: 2.5rem !important;
  color: var(--site-primary) !important;
  margin-bottom: 2rem !important;
  font-weight: 900 !important;
  border-left: 8px solid var(--site-accent);
  padding-left: 1.5rem;
}

.content li,
.body-content li {
  position: relative;
  padding-left: 2.5rem;
  margin-bottom: 1rem;
  font-size: 1.15rem;
}

.content li::before,
.body-content li::before {
  content: '✓';
  position: absolute;
  left: 0;
  top: 0.1em;
  width: 28px;
  height: 28px;
  background: var(--site-primary-glow);
  color: var(--site-primary);
  border-radius: 50%;
  display: flex;
  align-items: center;
  justify-content: center;
  font-weight: 900;
  font-size: 0.85rem;
}

/* ========================================
   Site Header (Glassmorphism)
   ======================================== */
.site-header {
  position: sticky;
  top: 0;
  z-index: 1000;
  background: var(--glass-bg);
  backdrop-filter: blur(var(--glass-blur));
  -webkit-backdrop-filter: blur(var(--glass-blur));
  border-bottom: 1px solid var(--glass-border);
  padding: 0.75rem 0;
  box-shadow: var(--shadow-sm);
  transition: var(--transition-base);
}

/* .site-header .container — inherits from main.css .container (padding: 0 2rem) */

.logo {
  display: flex;
  align-items: center;
  gap: 1.25rem;
  text-decoration: none;
  transition: var(--transition-smooth);
}

.logo-wrapper {
  width: 44px;
  height: 44px;
  display: flex;
  align-items: center;
  justify-content: center;
  transition: var(--transition-smooth);
}

.logo-svg {
  width: 100%;
  height: 100%;
}

.logo:hover .logo-wrapper {
  transform: scale(1.05);
}

.logo .site-name {
  font-size: 1.7rem;
  font-weight: 700;
  letter-spacing: -0.04em;
  color: var(--site-text);
  transition: var(--transition-base);
}

.main-nav ul {
  display: flex;
  gap: 2rem;
  list-style: none;
  margin: 0;
  padding: 0;
}

.main-nav a {
  color: var(--site-text);
  font-weight: 600;
  text-decoration: none;
  font-size: 0.95rem;
  position: relative;
  transition: var(--transition-base);
}

.main-nav a::after {
  content: '';
  position: absolute;
  bottom: -4px;
  left: 0;
  width: 0;
  height: 2px;
  background: var(--site-primary);
  transition: var(--transition-base);
  border-radius: var(--radius-full);
}

.main-nav a:hover {
  color: var(--site-primary);
}

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

/* ========================================
   Page Header Section (Editorial Edition)
   ======================================== */
.page-header-section {
  position: relative;
  background: linear-gradient(135deg, var(--site-primary), var(--site-primary-dark));
  color: white;
  padding: 6rem 2rem;
  margin: 0 0 4rem;
  border-radius: var(--radius-lg);
  overflow: hidden;
  text-align: center;
  z-index: 10;
}

.page-header-section h1 {
  font-size: 3.5rem;
  margin: 0;
  font-weight: 700;
  position: relative;
  z-index: 2;
  letter-spacing: -0.05em;
  text-shadow: 0 4px 15px rgba(0, 0, 0, 0.1);
}

.page-header-section .subtitle {
  font-size: 1.5rem;
  opacity: 0.9;
  margin: 1.5rem auto 0;
  max-width: 600px;
  font-weight: 400;
  position: relative;
  z-index: 2;
  line-height: 1.5;
}

.breadcrumb {
  margin-bottom: 1.5rem;
  position: relative;
  z-index: 5;
}

.breadcrumb ol {
  display: flex;
  list-style: none;
  padding: 0.4rem 1.2rem;
  gap: 0.75rem;
  font-size: 0.95rem;
  font-weight: 600;
  background: rgba(0, 0, 0, 0.15);
  backdrop-filter: blur(4px);
  border-radius: var(--radius-full);
  border: 1px solid rgba(255, 255, 255, 0.1);
}

.breadcrumb a {
  color: #ffffff;
  text-decoration: none;
  transition: var(--transition-base);
  text-shadow: 0 1px 2px rgba(0, 0, 0, 0.2);
}

.breadcrumb a:hover {
  color: var(--site-accent);
  text-decoration: underline;
}

.breadcrumb li {
  display: flex;
  align-items: center;
  color: rgba(255, 255, 255, 0.9);
}

.breadcrumb li+li::before {
  content: "›";
  margin-right: 0.75rem;
  color: rgba(255, 255, 255, 0.4);
  font-size: 1.2rem;
  line-height: 1;
}

/* ========================================
   Intro Section
   ======================================== */
.intro {
  margin: 0 auto 3rem;
  padding: 2rem;
  background: var(--glass-bg);
  backdrop-filter: blur(var(--glass-blur));
  border: 1px solid var(--glass-border);
  border-radius: var(--radius-md);
  box-shadow: var(--shadow-md);
  text-align: center;
}

.intro p {
  font-size: 1.1rem;
  line-height: 1.7;
  color: var(--site-text-muted);
  margin: 0;
}


/* ========================================
   Set Switcher
   ======================================== */
.set-switcher {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 1rem;
  margin: 3rem 0;
  padding: 1.5rem;
  background: var(--site-surface);
  backdrop-filter: blur(var(--glass-blur));
  border: 1px solid var(--glass-border);
  border-radius: var(--radius-lg);
  box-shadow: var(--shadow-md);
}

.set-switcher-label {
  font-weight: 700;
  color: var(--site-text);
  margin-right: 0.5rem;
  font-size: 1rem;
}

.set-btn {
  min-width: 44px;
  height: 44px;
  padding: 0.5rem;
  border: 1px solid var(--site-border);
  background: var(--site-surface-solid);
  color: var(--site-text-muted);
  border-radius: var(--radius-md);
  font-size: 1rem;
  font-weight: 700;
  cursor: pointer;
  transition: var(--transition-base);
  text-decoration: none;
  display: inline-flex;
  align-items: center;
  justify-content: center;
}

.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: white;
  border-color: var(--site-primary);
  box-shadow: 0 4px 12px var(--site-primary-glow);
}

/* ========================================
   Action Buttons
   ======================================== */
.actions {
  display: flex;
  gap: 1.25rem;
  justify-content: center;
  margin: 2.5rem 0;
  flex-wrap: wrap;
}

.btn {
  padding: 0.75rem 1.75rem;
  border: none;
  border-radius: var(--radius-full);
  font-size: 1rem;
  font-weight: 700;
  cursor: pointer;
  transition: var(--transition-base);
  text-decoration: none;
  display: inline-flex;
  align-items: center;
  gap: 0.75rem;
  box-shadow: var(--shadow-md);
}

.btn:active {
  transform: scale(0.98);
}

.btn-print {
  background: linear-gradient(135deg, var(--site-primary), var(--site-primary-dark));
  color: white;
}

.btn-print:hover {
  box-shadow: 0 8px 20px var(--site-primary-glow);
  transform: translateY(-2px);
}

.btn-answers {
  background: linear-gradient(135deg, var(--site-accent), var(--site-accent-hover));
  color: white;
}

.btn-answers:hover {
  box-shadow: 0 8px 20px rgba(13, 148, 136, 0.28);
  transform: translateY(-2px);
}

.btn-pdf {
  background: linear-gradient(135deg, var(--site-secondary), #be123c);
  color: white;
}

.btn-pdf:hover {
  box-shadow: 0 8px 20px rgba(244, 63, 94, 0.3);
  transform: translateY(-2px);
}

/* ========================================
   Worksheet Content
   ======================================== */
.worksheet-content {
  margin: 3rem 0;
  padding: 3rem;
  background: var(--site-surface-solid);
  border-radius: var(--radius-lg);
  border: 1px solid var(--site-border);
  box-shadow: var(--shadow-premium);
  position: relative;
}

.worksheet-title {
  text-align: center;
  font-size: 2rem;
  color: var(--site-text);
  margin-bottom: 3rem;
  padding-bottom: 1.5rem;
  border-bottom: 2px solid var(--site-border-light);
  font-weight: 700;
}

/* ========================================
   Vocabulary List
   ======================================== */
.vocabulary-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(240px, 1fr));
  gap: 1.5rem;
}

.vocab-item {
  padding: 1.25rem;
  background: var(--site-surface-dark);
  border-radius: var(--radius-md);
  display: flex;
  align-items: center;
  gap: 1rem;
  border: 1px solid transparent;
  transition: var(--transition-base);
}

.vocab-item:hover {
  background: white;
  border-color: var(--site-primary);
  transform: translateY(-3px);
  box-shadow: var(--shadow-md);
}

.vocab-item .num {
  background: var(--site-primary-light);
  color: var(--site-primary);
  font-weight: 700;
  width: 2.5rem;
  height: 2.5rem;
  border-radius: 50%;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 0.9rem;
}

.vocab-item .word {
  font-size: 1.2rem;
  font-weight: 600;
  color: var(--site-text);
}


/* ========================================
   Spelling Practice
   ======================================== */
.spelling-grid {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 1.5rem;
}

.spelling-item {
  padding: 1.25rem;
  background: var(--site-surface-dark);
  border-radius: var(--radius-md);
  display: grid;
  grid-template-columns: auto 1fr auto;
  gap: 1rem;
  align-items: center;
  border: 1px solid transparent;
  transition: var(--transition-base);
}

.spelling-item:hover {
  background: white;
  border-color: var(--site-accent);
}

.spelling-item .num {
  color: var(--site-accent);
  font-weight: 700;
  font-size: 0.9rem;
}

.spelling-item .scrambled {
  font-size: 1.1rem;
  font-family: 'JetBrains Mono', monospace;
  letter-spacing: 0.15em;
  color: var(--site-accent-dark);
  background: white;
  padding: 0.5rem 1rem;
  border-radius: var(--radius-sm);
  border: 1px dashed var(--site-accent);
  text-align: center;
}

.spelling-item .blank {
  border-bottom: 2px solid var(--site-primary);
  min-width: 120px;
  height: 2rem;
  background: white;
  border-radius: var(--radius-sm);
}

.spelling-item .answer {
  color: var(--site-primary);
  font-weight: 700;
  font-size: 1.1rem;
  display: none;
  background: var(--site-accent-light);
  padding: 0.5rem 1rem;
  border-radius: var(--radius-sm);
  animation: fadeIn 0.3s ease;
}

@keyframes fadeIn {
  from {
    opacity: 0;
    transform: translateY(5px);
  }

  to {
    opacity: 1;
    transform: translateY(0);
  }
}

.show-answers .spelling-item .answer {
  display: block;
}

.show-answers .spelling-item .blank {
  display: none;
}

/* ========================================
   Tracing Practice
   ======================================== */
.tracing-grid {
  display: grid;
  gap: 2.5rem;
}

.tracing-item {
  padding: 2.5rem;
  background: var(--site-surface-dark);
  border-radius: var(--radius-lg);
  border: 1px solid var(--site-border);
}

.tracing-item .word-display {
  font-size: 3.5rem;
  font-weight: 700;
  color: var(--site-primary);
  margin-bottom: 1.5rem;
  text-align: center;
  letter-spacing: 0.1em;
}

.tracing-item .trace-line {
  height: 80px;
  border: 2px dashed var(--site-border);
  border-radius: var(--radius-md);
  background: repeating-linear-gradient(0deg,
      transparent,
      transparent 38px,
      var(--site-border-light) 38px,
      var(--site-border-light) 40px);
  margin-bottom: 1rem;
}

.tracing-item .dotted {
  font-size: 3rem;
  font-family: 'Outfit', monospace;
  color: var(--site-text-light);
  letter-spacing: 0.6em;
  text-align: center;
  opacity: 0.4;
}

/* ========================================
   Matching Exercise
   ======================================== */
.matching-container {
  display: flex;
  justify-content: space-around;
  gap: 3rem;
  flex-wrap: wrap;
}

.matching-column {
  flex: 1;
  min-width: 280px;
}

.matching-column h3 {
  text-align: center;
  color: var(--site-text);
  margin-bottom: 1.5rem;
  padding-bottom: 0.75rem;
  border-bottom: 3px solid var(--site-primary);
  font-weight: 700;
  font-size: 1.25rem;
}

.matching-item {
  padding: 0.85rem 1.25rem;
  margin-bottom: 0.75rem;
  background: var(--site-surface-dark);
  border-radius: var(--radius-md);
  font-size: 1.1rem;
  font-weight: 600;
  text-align: center;
  border: 1px solid var(--site-border);
  transition: var(--transition-base);
  cursor: pointer;
}

.matching-item:hover {
  border-color: var(--site-primary);
  background: white;
  transform: translateX(5px);
  box-shadow: var(--shadow-sm);
}

.matching-item .num {
  display: inline-flex;
  width: 1.75rem;
  height: 1.75rem;
  align-items: center;
  justify-content: center;
  background: var(--site-primary);
  color: white;
  border-radius: 50%;
  margin-right: 0.75rem;
  font-size: 0.85rem;
  font-weight: 700;
}

/* ========================================
   Fill in the Blank
   ======================================== */
.fill-blank-grid {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 1.25rem 2rem;
}

.fill-blank-item {
  padding: 1rem 1.25rem;
  background: var(--site-surface-dark);
  border-radius: var(--radius-md);
  display: flex;
  align-items: center;
  gap: 1rem;
  border: 1px solid transparent;
  transition: var(--transition-base);
}

.fill-blank-item:hover {
  background: white;
  border-color: var(--site-accent);
}

.fill-blank-item .num {
  color: var(--site-primary);
  font-weight: 700;
  font-size: 1rem;
  min-width: 2.25rem;
}

.fill-blank-item .blanked {
  font-size: 1.25rem;
  font-family: 'Outfit', sans-serif;
  letter-spacing: 0.1em;
  color: var(--site-text);
  font-weight: 600;
}

.fill-blank-item .blanked .blank-char {
  color: var(--site-accent);
  font-weight: 700;
  text-decoration: underline;
}

.fill-blank-item .hint {
  font-size: 0.85rem;
  color: var(--site-text-light);
  font-style: italic;
  margin-left: auto;
}

.fill-blank-item .answer {
  color: white;
  font-weight: 700;
  font-size: 1rem;
  display: none;
  background: var(--site-accent);
  padding: 0.4rem 0.85rem;
  border-radius: var(--radius-sm);
  animation: fadeIn 0.3s ease;
}

.show-answers .fill-blank-item .answer {
  display: block;
}

/* ========================================
   Flashcards
   ======================================== */
.flashcards-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(220px, 1fr));
  gap: 2rem;
}

.flashcard {
  aspect-ratio: 5/7;
  background: white;
  border: 3px solid var(--site-primary);
  border-radius: var(--radius-lg);
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  padding: 2.5rem;
  text-align: center;
  transition: var(--transition-smooth);
  cursor: pointer;
  box-shadow: var(--shadow-md);
  position: relative;
  overflow: hidden;
}

.flashcard:hover {
  transform: translateY(-10px) rotate(2deg);
  box-shadow: var(--shadow-premium);
  border-color: var(--site-accent);
}

.flashcard::before {
  content: '';
  position: absolute;
  top: 0;
  left: 0;
  width: 100%;
  height: 10px;
  background: var(--site-primary);
}

.flashcard .front {
  font-size: 2.5rem;
  font-weight: 700;
  color: var(--site-text);
  margin-bottom: 2rem;
}

.flashcard .back {
  font-size: 1.5rem;
  color: var(--site-primary);
  font-weight: 700;
  padding-top: 2rem;
  border-top: 3px dashed var(--site-border-light);
  width: 100%;
}

/* ========================================
   Bingo Card
   ======================================== */
.bingo-container {
  max-width: 600px;
  margin: 3rem auto;
}

.bingo-header {
  display: grid;
  grid-template-columns: repeat(5, 1fr);
  gap: 0.5rem;
  margin-bottom: 1rem;
}

.bingo-header-cell {
  text-align: center;
  font-size: 2rem;
  font-weight: 900;
  color: var(--site-text-on-primary);
  background: var(--site-primary);
  padding: 0.75rem;
  border-radius: var(--radius-md);
  box-shadow: var(--shadow-sm);
}

.bingo-grid {
  display: grid;
  grid-template-columns: repeat(5, 1fr);
  gap: 0.5rem;
  padding: 0.75rem;
  background: var(--site-primary-dark);
  border-radius: var(--radius-lg);
  box-shadow: var(--shadow-lg);
}

.bingo-cell {
  aspect-ratio: 1;
  display: flex;
  align-items: center;
  justify-content: center;
  background: white;
  font-size: 1rem;
  font-weight: 700;
  padding: 0.75rem;
  text-align: center;
  border-radius: var(--radius-sm);
  word-break: break-word;
  transition: var(--transition-base);
  color: var(--site-text);
  border: 1px solid var(--site-border-light);
}

.bingo-cell:hover {
  transform: scale(1.05);
  z-index: 10;
  box-shadow: var(--shadow-md);
}

.bingo-cell.free {
  background: var(--site-accent);
  color: white;
  font-weight: 900;
  text-transform: uppercase;
  font-size: 0.85rem;
}

/* ========================================
   Word List
   ======================================== */
.word-list-grid {
  column-count: 3;
  column-gap: 2.5rem;
}

.word-list-item {
  break-inside: avoid;
  padding: 1rem 1.25rem;
  margin-bottom: 1rem;
  background: var(--site-surface-dark);
  border-radius: var(--radius-md);
  display: flex;
  align-items: center;
  gap: 1.25rem;
  border: 1px solid transparent;
  transition: var(--transition-base);
}

.word-list-item:hover {
  background: white;
  border-color: var(--site-primary);
  box-shadow: var(--shadow-sm);
}

.word-list-item .num {
  color: var(--site-primary);
  font-weight: 700;
  min-width: 2.5rem;
}

.word-list-item .word {
  font-size: 1.15rem;
  font-weight: 600;
  color: var(--site-text);
}

.word-list-item .length {
  background: var(--site-border-light);
  color: var(--site-text-light);
  font-size: 0.75rem;
  padding: 0.2rem 0.6rem;
  border-radius: var(--radius-full);
  margin-left: auto;
  font-weight: 700;
}

/* ========================================
   Navigation
   ======================================== */
.page-navigation {
  display: flex;
  justify-content: center;
  gap: 1.5rem;
  margin: 4rem 0;
  flex-wrap: wrap;
}

.btn-nav {
  padding: 1rem 2rem;
  background: white;
  color: var(--site-primary);
  border: 2px solid var(--site-primary);
  border-radius: var(--radius-full);
  font-weight: 700;
  text-decoration: none;
  transition: var(--transition-base);
  font-size: 1rem;
  box-shadow: var(--shadow-md);
}

.btn-nav:hover {
  background: var(--site-primary);
  color: white;
  transform: translateY(-3px);
  box-shadow: 0 8px 20px var(--site-primary-glow);
}

.btn-nav.disabled {
  opacity: 0.5;
  cursor: not-allowed;
  background: var(--site-surface-dark);
  color: var(--site-text-light);
  border-color: var(--site-border);
  box-shadow: none;
}

.btn-nav.disabled:hover {
  transform: none;
  box-shadow: none;
}

.btn-nav.back-to-list {
  background: var(--site-primary);
  color: white;
}

/* ========================================
   List Page Styles
   ======================================== */
.list-page .category-list,
.list-page .worksheet-list {
  list-style: none;
  padding: 0;
  display: grid;
  gap: 1.5rem;
}

.list-page .category-list {
  grid-template-columns: repeat(auto-fill, minmax(320px, 1fr));
}

.list-page .worksheet-list {
  grid-template-columns: repeat(auto-fill, minmax(280px, 1fr));
}

.list-page .category-list li a {
  display: block;
  padding: 2rem;
  background: var(--site-surface-solid);
  border-radius: var(--radius-lg);
  text-decoration: none;
  transition: var(--transition-base);
  border: 2px solid var(--site-border-light);
  box-shadow: var(--shadow-md);
}

.list-page .worksheet-card .card-icon {
  margin-bottom: 0.5rem;
  color: var(--site-primary);
  opacity: 0.8;
  transition: var(--transition-base);
}

.list-page .worksheet-card:hover .card-icon {
  transform: scale(1.1);
  opacity: 1;
}

.list-page .category-list li a:hover {

  border-color: var(--site-primary);
  transform: translateY(-5px);
  box-shadow: var(--shadow-lg);
}

.list-page .category-list .name {
  font-size: 1.35rem;
  font-weight: 700;
  color: var(--site-text);
  margin-bottom: 0.75rem;
  display: block;
}

.list-page .category-list .description {
  font-size: 1rem;
  color: var(--site-text-muted);
  line-height: 1.6;
}

.list-page .worksheet-card {
  display: flex;
  flex-direction: column;
  gap: 1rem;
  padding: 2rem;
  background: var(--site-surface-solid);
  border-radius: var(--radius-lg);
  text-decoration: none;
  transition: var(--transition-base);
  border: 2px solid var(--site-border-light);
  box-shadow: var(--shadow-md);
  text-align: center;
}

.list-page .worksheet-card:hover {
  border-color: var(--site-primary);
  transform: scale(1.03);
  box-shadow: var(--shadow-lg);
}

.list-page .worksheet-card .set-number {
  font-size: 1.75rem;
  font-weight: 900;
  color: var(--site-primary);
}

.list-page .worksheet-card .set-description {
  font-size: 1rem;
  color: var(--site-text-muted);
}

/* ========================================
   Homepage Styles
   ======================================== */
/* ========================================
   SEO Components (Premium Cards)
   ======================================== */
.seo-components {
  margin: 4rem 0;
}

.seo-components--primary {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
  gap: 2rem;
}

/* ========================================
   首页分类卡片深度美化 (Wow Factor)
   ======================================== */
.homepage .categories h2 {
  font-size: 2.75rem;
  font-weight: 900;
  margin: 5rem 0 3rem;
  text-align: center;
  color: var(--site-text);
  letter-spacing: -0.04em;
}

.homepage .category-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(360px, 1fr));
  gap: 2.5rem;
  list-style: none;
  padding: 0;
}

.homepage .category-grid li a {
  display: flex;
  flex-direction: column;
  padding: 5rem 3.5rem;
  background: white;
  border-radius: var(--radius-lg);
  text-decoration: none;
  transition: var(--transition-smooth);
  border: 1px solid var(--site-border-light);
  box-shadow: 0 10px 30px rgba(0, 0, 0, 0.03);
  text-align: center;
  position: relative;
  overflow: hidden;
}

.homepage .category-grid li a:hover {
  transform: translateY(-8px);
  box-shadow: 0 20px 40px rgba(0, 0, 0, 0.08);
  border-color: var(--site-primary);
}

.category-icon-wrapper {
  margin: 0 auto 3rem;
  width: 120px;
  height: 120px;
  display: flex;
  align-items: center;
  justify-content: center;
  transition: var(--transition-smooth);
}

.homepage .category-grid li a:hover .category-icon-wrapper {
  transform: scale(1.05);
}

.homepage .category-grid .name {
  font-size: 2.4rem;
  font-weight: 700;
  color: var(--site-text);
  margin-bottom: 1rem;
  display: block;
  letter-spacing: -0.05em;
  transition: var(--transition-base);
}

.homepage .category-grid li a:hover .name {
  color: var(--site-primary);
}

.homepage .category-grid .description {
  font-size: 1.25rem;
  color: var(--site-text-muted);
  line-height: 1.6;
  font-weight: 400;
  max-width: 300px;
  margin: 0 auto;
}

.go-arrow {
  margin-top: 3.5rem;
  color: var(--site-primary);
  opacity: 0.15;
  transform: translateY(10px);
  transition: var(--transition-smooth);
}

.homepage .category-grid li a:hover .go-arrow {
  opacity: 1;
  transform: translateY(0);
}


/* ========================================
   SEO Components (Premium Cards)
   ======================================== */
.seo-components {
  margin: 6rem 0;
}

.seo-components--primary {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(320px, 1fr));
  gap: 2.5rem;
}

.seo-card {
  background: white;
  border-radius: var(--radius-lg);
  padding: 3rem;
  box-shadow: var(--shadow-md);
  transition: var(--transition-smooth);
  position: relative;
  overflow: hidden;
  border: 1px solid var(--site-border-light);
  display: flex;
  flex-direction: column;
  gap: 1.5rem;
}

.seo-card:hover {
  transform: translateY(-10px);
  box-shadow: var(--shadow-premium);
}

.seo-card .seo-icon {
  width: 56px;
  height: 56px;
  display: flex;
  align-items: center;
  justify-content: center;
  border-radius: var(--radius-md);
  margin-bottom: 0.5rem;
  transition: var(--transition-base);
}

.seo-card:hover .seo-icon {
  transform: scale(1.1) rotate(5deg);
}

.seo-card.features .seo-icon {
  background: rgba(244, 63, 94, 0.1);
  color: #f43f5e;
}

.seo-card.benefits .seo-icon {
  background: rgba(16, 185, 129, 0.1);
  color: #10b981;
}

.seo-card.faq .seo-icon {
  background: rgba(99, 102, 241, 0.1);
  color: #6366f1;
}

.seo-card.tips .seo-icon {
  background: rgba(245, 158, 11, 0.1);
  color: #f59e0b;
}

.seo-card.steps .seo-icon {
  background: rgba(139, 92, 246, 0.1);
  color: #8b5cf6;
}

.seo-card h2,
.seo-card h3 {
  font-size: 1.6rem;
  color: var(--site-text);
  margin: 0;
  font-weight: 700;
}

.seo-card p,
.seo-block p {
  color: var(--site-text-muted);
  line-height: 1.8;
  margin: 0;
}

/* Secondary SEO */
.seo-components--secondary {
  margin-top: 5rem;
}

.content-toggle {
  background: var(--glass-bg);
  backdrop-filter: blur(var(--glass-blur));
  -webkit-backdrop-filter: blur(var(--glass-blur));
  border: 1px solid var(--glass-border);
  border-radius: var(--radius-lg);
  overflow: hidden;
}

.content-toggle summary {
  padding: 2rem;
  font-weight: 700;
  font-size: 1.5rem;
  cursor: pointer;
  list-style: none;
  color: var(--site-primary);
  display: flex;
  align-items: center;
  justify-content: space-between;
}

.seo-more-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
  gap: 2rem;
  padding: 3rem;
  background: rgba(255, 255, 255, 0.3);
}

.seo-block {
  padding: 2rem;
  background: white;
  border-radius: var(--radius-md);
  border: 1px solid var(--site-border-light);
  transition: var(--transition-base);
}

.seo-block:hover {
  border-color: var(--site-primary);
  box-shadow: var(--shadow-md);
}

/* ========================================
   Site Footer
   ======================================== */
.site-footer {
  margin-top: 8rem;
  padding: 6rem 0;
  background: var(--site-surface-dark);
  border-top: 1px solid var(--site-border);
  color: var(--site-text-muted);
  text-align: center;
}

.site-footer .container {
  max-width: 1200px;
  margin: 0 auto;
  padding: 0 1.5rem;
}

.site-footer nav ul {
  display: flex;
  justify-content: center;
  gap: 3rem;
  list-style: none;
  margin: 3rem 0 0;
  padding: 0;
}

.site-footer nav a {
  color: var(--site-text-muted);
  text-decoration: none;
  font-weight: 600;
  transition: var(--transition-base);
}

@media (max-width: 768px) {
  .page-header-section {
    padding: 3rem 1.5rem;
    margin-bottom: 2rem;
  }

  .page-header-section h1 {
    font-size: 2rem;
  }

  .worksheet-content {
    padding: 2rem;
  }

  .worksheet-title {
    font-size: 1.75rem;
  }

  .word-list-grid {
    column-count: 2;
  }

  .fill-blank-grid {
    grid-template-columns: 1fr;
    gap: 1rem;
  }

  .seo-components--primary {
    grid-template-columns: 1fr;
    gap: 1.5rem;
  }

  .homepage .category-grid {
    grid-template-columns: 1fr;
  }
}

@media (max-width: 480px) {
  .page-header-section {
    padding: 2.5rem 1rem;
  }

  .page-header-section h1 {
    font-size: 1.5rem;
  }

  .worksheet-content {
    padding: 1.5rem;
  }

  .word-list-grid {
    column-count: 1;
  }

  .flashcards-grid {
    grid-template-columns: 1fr;
  }

  .site-footer nav ul {
    flex-direction: column;
    gap: 1rem;
  }
}

/* ═══════════════════════════════════════════════════════════
   Phase 1 Interaction Styles
   ═══════════════════════════════════════════════════════════ */
.ia-mode-splitter {
  display: inline-flex;
  gap: 0.5rem;
  margin-bottom: 0.5rem;
}

.ia-feedback-mode-toggle {
  display: inline-flex;
  gap: 0.25rem;
  padding: 0.25rem;
  background: var(--bg-card, #f8fafc);
  border-radius: var(--ia-radius, 8px);
  border: 1px solid var(--border-color, #e2e8f0);
}

.input-correct {
  border-color: var(--ia-success-color, #22c55e) !important;
  background: rgba(34, 197, 94, 0.06) !important;
}

.input-incorrect {
  border-color: var(--ia-error-color, #ef4444) !important;
  background: rgba(239, 68, 68, 0.06) !important;
}

.feedback-icon {
  display: inline-flex;
  align-items: center;
  width: 1.25rem;
  height: 1.25rem;
  font-size: 0.875rem;
  font-weight: 700;
  margin-left: 0.25rem;
}

.feedback-icon--correct { color: var(--ia-success-color, #22c55e); }
.feedback-icon--incorrect { color: var(--ia-error-color, #ef4444); }

@media print {
  .ia-mode-splitter,
  .ia-feedback-mode-toggle,
  .ia-game-controls,
  .check-plugin-wrapper,
  .ia-data-panel,
  .ia-daily-challenge {
    display: none !important;
  }
}