/* ============================================
   App SPA Styles — extends design-tokens.css & components.css
   App name configured in js/app-config.js
   ============================================ */

:root {
  --accent-gold: #FFD700;
  --accent-correct: #22C55E;
  --accent-wrong: #EF4444;
}

/* ============================================
   APP CONTAINER & LAYOUT
   ============================================ */
.app-container {
  position: relative;
  z-index: 10;
  max-width: var(--container-max);
  margin: 0 auto;
  min-height: 100vh;
  padding: 0;
}

.app-main {
  padding: 0 1.5rem 3rem;
}

@media (max-width: 640px) {
  .app-main {
    padding: 0 1rem 2rem;
  }
}

/* ============================================
   APP HEADER (glass style matching page-header)
   ============================================ */
.app-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 0.75rem 1.5rem;
  background: var(--glass-bg);
  backdrop-filter: blur(var(--glass-blur));
  -webkit-backdrop-filter: blur(var(--glass-blur));
  border-bottom: 1px solid var(--brand-border);
  position: sticky;
  top: 0;
  z-index: 100;
}

.app-header .logo {
  display: flex;
  align-items: center;
  gap: 8px;
  font-size: 22px;
  font-weight: 800;
  color: var(--accent-teal);
  text-decoration: none;
  letter-spacing: -0.5px;
}

.header-back {
  background: none;
  border: none;
  font-size: 24px;
  cursor: pointer;
  padding: 4px;
  color: var(--text-body);
  display: none;
  align-items: center;
  gap: 6px;
  transition: color 0.2s;
}

.header-back:hover {
  color: var(--accent-teal);
}

.header-back.show { display: flex; }

.header-right {
  display: flex;
  align-items: center;
  gap: 8px;
}

.header-xp {
  display: flex;
  align-items: center;
  gap: 6px;
  font-weight: 600;
  font-size: 14px;
  color: var(--accent-gold);
  background: rgba(255, 215, 0, 0.1);
  border: 1px solid rgba(255, 215, 0, 0.2);
  padding: 6px 12px;
  border-radius: 20px;
}

.header-premium-btn {
  background: linear-gradient(135deg, #FFD700, #FFA500);
  border: none;
  width: 36px;
  height: 36px;
  border-radius: 50%;
  font-size: 18px;
  cursor: pointer;
  transition: all 0.3s;
  display: flex;
  align-items: center;
  justify-content: center;
  box-shadow: 0 2px 8px rgba(255, 165, 0, 0.3);
}

.header-premium-btn:hover { transform: scale(1.1); }

/* ============================================
   PAGE SYSTEM
   ============================================ */
.page {
  display: none;
  animation: fadeIn 0.3s ease;
}

.page.active { display: block; }

@keyframes fadeIn {
  from { opacity: 0; transform: translateY(10px); }
  to { opacity: 1; transform: translateY(0); }
}

@keyframes slideUp {
  from { opacity: 0; transform: translateY(30px); }
  to { opacity: 1; transform: translateY(0); }
}

@keyframes pop {
  0% { transform: scale(0.5); opacity: 0; }
  70% { transform: scale(1.1); }
  100% { transform: scale(1); opacity: 1; }
}

@keyframes shake {
  0%, 100% { transform: translateX(0); }
  25% { transform: translateX(-5px); }
  75% { transform: translateX(5px); }
}

@keyframes confetti-fall {
  0% { transform: translateY(-10px) rotate(0deg); opacity: 1; }
  100% { transform: translateY(100px) rotate(720deg); opacity: 0; }
}

/* ============================================
   WELCOME PAGE
   ============================================ */
.welcome-container {
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  min-height: 80vh;
  padding: 60px 24px;
  text-align: center;
}

.welcome-logo { margin-bottom: 24px; }

.welcome-logo svg {
  filter: drop-shadow(0 0 30px rgba(20, 184, 166, 0.3));
}

.welcome-title {
  font-size: 2.5rem;
  font-weight: 800;
  color: var(--text-heading);
  margin-bottom: 8px;
}

.welcome-subtitle {
  font-size: 16px;
  color: var(--text-muted);
  margin-bottom: 32px;
  line-height: 1.6;
  max-width: 440px;
}

.welcome-form {
  width: 100%;
  max-width: 400px;
  display: flex;
  flex-direction: column;
  gap: 12px;
}

.welcome-input {
  width: 100%;
  padding: 16px 20px;
  background: var(--brand-card);
  border: 1px solid var(--brand-border);
  border-radius: var(--radius-md);
  font-size: 16px;
  font-family: var(--font-family);
  color: var(--text-heading);
  transition: border-color 0.3s;
  outline: none;
}

.welcome-input::placeholder {
  color: var(--text-muted);
}

.welcome-input:focus {
  border-color: var(--accent-teal);
  box-shadow: 0 0 0 3px rgba(20, 184, 166, 0.15);
}

.welcome-input.error {
  border-color: var(--accent-wrong);
  animation: shake 0.3s ease;
}

.welcome-btn {
  width: 100%;
  padding: 16px;
  background: var(--gradient-primary);
  color: #0F172A;
  border: none;
  border-radius: var(--radius-md);
  font-size: 18px;
  font-weight: 700;
  cursor: pointer;
  transition: all 0.3s;
  font-family: var(--font-family);
}

.welcome-btn:hover {
  transform: translateY(-2px);
  box-shadow: 0 8px 25px rgba(20, 184, 166, 0.25);
}

.welcome-btn:active { transform: translateY(0); }

.welcome-note {
  font-size: 13px;
  color: var(--text-muted);
  margin-top: 4px;
}

/* ============================================
   DASHBOARD PAGE
   ============================================ */
.dash-greeting {
  display: flex;
  align-items: center;
  gap: 16px;
  padding: 24px 0 8px;
}

.dash-greeting .dash-avatar { font-size: 48px; }

.dash-greeting .dash-hello {
  font-size: 1.75rem;
  font-weight: 800;
  color: var(--text-heading);
}

.dash-greeting .dash-email {
  font-size: 14px;
  color: var(--text-muted);
}

.dash-section {
  padding: 16px 0 0;
}

.dash-section-label {
  font-size: 0.75rem;
  font-weight: 700;
  color: var(--text-muted);
  margin-bottom: 10px;
  text-transform: uppercase;
  letter-spacing: 0.1em;
}

.lang-selector {
  display: flex;
  gap: 8px;
  flex-wrap: wrap;
}

.lang-btn {
  display: flex;
  align-items: center;
  gap: 6px;
  padding: 8px 16px;
  border-radius: 20px;
  border: 1px solid var(--brand-border);
  background: var(--brand-card);
  font-size: 14px;
  font-weight: 600;
  cursor: pointer;
  transition: all 0.3s;
  white-space: nowrap;
  font-family: var(--font-family);
  color: var(--text-body);
}

.lang-btn:hover {
  border-color: var(--accent-teal);
  color: var(--accent-teal);
}

.lang-btn.active {
  border-color: var(--accent-teal);
  background: rgba(20, 184, 166, 0.12);
  color: var(--accent-teal);
}

.lang-btn.coming-soon {
  opacity: 0.45;
  pointer-events: auto;
  cursor: help;
  position: relative;
}

.lang-btn.coming-soon:hover {
  opacity: 0.75;
  border-color: var(--brand-border);
  color: var(--text-body);
}

/* Hover note for disabled (not-yet-available) study languages */
.lang-btn.coming-soon::after {
  content: attr(data-tip);
  position: absolute;
  bottom: calc(100% + 10px);
  left: 50%;
  transform: translateX(-50%) translateY(6px);
  width: max-content;
  max-width: 220px;
  padding: 8px 12px;
  border-radius: 10px;
  background: var(--brand-card);
  border: 1px solid var(--accent-teal);
  color: var(--text-body);
  font-size: 12px;
  font-weight: 600;
  line-height: 1.35;
  text-align: center;
  white-space: normal;
  box-shadow: 0 8px 24px rgba(0, 0, 0, 0.35);
  opacity: 0;
  pointer-events: none;
  transition: opacity 0.2s ease, transform 0.2s ease;
  z-index: 20;
}

.lang-btn.coming-soon:hover::after {
  opacity: 1;
  transform: translateX(-50%) translateY(0);
}

.level-filter {
  display: flex;
  gap: 8px;
  flex-wrap: wrap;
}

.level-filter .lv-btn {
  padding: 8px 16px;
  border-radius: 20px;
  border: 1px solid var(--brand-border);
  background: var(--brand-card);
  font-size: 13px;
  font-weight: 600;
  cursor: pointer;
  transition: all 0.3s;
  white-space: nowrap;
  font-family: var(--font-family);
  color: var(--text-body);
}

.level-filter .lv-btn:hover {
  border-color: var(--text-muted);
  color: var(--text-heading);
}

.level-filter .lv-btn.active {
  border-color: var(--accent-teal);
  background: rgba(20, 184, 166, 0.12);
  color: var(--accent-teal);
}

.level-filter .lv-btn.locked {
  border-color: var(--brand-border);
  color: var(--text-muted);
  opacity: 0.5;
  pointer-events: none;
}

.dash-stats {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 10px;
  padding: 16px 0;
}

.dash-stat {
  background: var(--brand-card);
  border: 1px solid var(--brand-border);
  border-radius: var(--radius-md);
  padding: 16px 8px;
  text-align: center;
  transition: border-color 0.2s;
}

.dash-stat:hover {
  border-color: rgba(20, 184, 166, 0.3);
}

.dash-stat-num {
  font-size: 1.5rem;
  font-weight: 800;
  color: var(--accent-teal);
  display: block;
}

.dash-stat-lbl {
  font-size: 11px;
  color: var(--text-muted);
  margin-top: 4px;
}

.dash-categories {
  display: flex;
  flex-direction: column;
  gap: 8px;
}

.dash-cat-card {
  display: flex;
  align-items: center;
  gap: 12px;
  padding: 12px 16px;
  background: var(--brand-card);
  border: 1px solid var(--brand-border);
  border-radius: var(--radius-md);
  cursor: pointer;
  transition: all 0.3s;
}

.dash-cat-card:hover {
  border-color: var(--accent-teal);
  background: rgba(20, 27, 45, 0.8);
  transform: translateX(4px);
}

.dash-cat-card:active { transform: scale(0.99); }

.dash-cat-card .dcc-icon { font-size: 28px; }

.dash-cat-card .dcc-info { flex: 1; min-width: 0; }

.dash-cat-card .dcc-name {
  font-size: 15px;
  font-weight: 700;
  color: var(--text-heading);
}

.dash-cat-card .dcc-meta {
  font-size: 12px;
  color: var(--text-muted);
}

.dash-cat-card .dcc-premium-badge {
  font-size: 11px;
  background: linear-gradient(135deg, #FFD700, #FFA500);
  color: white;
  padding: 3px 10px;
  border-radius: 20px;
  font-weight: 700;
  white-space: nowrap;
  flex-shrink: 0;
}

.dash-view-all {
  display: block;
  width: 100%;
  padding: 12px;
  margin-top: 8px;
  background: none;
  border: 1px dashed var(--brand-border);
  border-radius: var(--radius-md);
  font-size: 14px;
  font-weight: 600;
  color: var(--text-muted);
  cursor: pointer;
  transition: all 0.3s;
  font-family: var(--font-family);
  text-align: center;
}

.dash-view-all:hover {
  border-color: var(--accent-teal);
  color: var(--accent-teal);
}

.dash-quick-actions {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 10px;
  padding: 16px 0;
}

.dash-qa-btn {
  padding: 18px 16px;
  background: var(--brand-card);
  border: 1px solid var(--brand-border);
  border-radius: var(--radius-md);
  font-size: 14px;
  font-weight: 600;
  cursor: pointer;
  transition: all 0.3s;
  font-family: var(--font-family);
  text-align: center;
  color: var(--text-body);
}

.dash-qa-btn:hover {
  border-color: var(--accent-teal);
  color: var(--accent-teal);
  background: rgba(20, 27, 45, 0.8);
  transform: translateY(-2px);
}

.dash-logout {
  display: block;
  width: 100%;
  padding: 12px;
  background: none;
  border: 1px solid rgba(239, 68, 68, 0.3);
  border-radius: var(--radius-md);
  font-size: 14px;
  font-weight: 600;
  color: var(--accent-wrong);
  cursor: pointer;
  transition: all 0.3s;
  font-family: var(--font-family);
  margin-bottom: 24px;
}

.dash-logout:hover {
  background: rgba(239, 68, 68, 0.08);
  border-color: var(--accent-wrong);
}

/* ============================================
   CATEGORIES PAGE
   ============================================ */
.categories-header {
  padding: 24px 0 16px;
  font-size: 1.5rem;
  font-weight: 700;
  color: var(--text-heading);
}

.categories-level-filter {
  padding: 0 0 16px;
}

.categories-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(200px, 1fr));
  gap: 12px;
  padding: 0 0 20px;
}

.category-card {
  background: var(--brand-card);
  border: 1px solid var(--brand-border);
  border-radius: var(--radius-lg);
  padding: 20px;
  cursor: pointer;
  transition: all 0.3s;
  position: relative;
  overflow: hidden;
}

.category-card:hover {
  border-color: var(--accent-teal);
  background: rgba(20, 27, 45, 0.8);
  transform: translateY(-3px);
}

.category-card:active { transform: scale(0.97); }

.category-card .cat-icon { font-size: 36px; margin-bottom: 8px; }

.category-card .cat-name {
  font-size: 15px;
  font-weight: 700;
  color: var(--text-heading);
  margin-bottom: 4px;
}

.category-card .cat-count {
  font-size: 12px;
  color: var(--text-muted);
}

.category-card .diff-badge {
  display: inline-block;
  font-size: 10px;
  font-weight: 600;
  padding: 3px 10px;
  border-radius: 20px;
  margin-top: 6px;
  color: white;
}

.category-card .mastery-bar {
  height: 4px;
  background: rgba(255, 255, 255, 0.06);
  border-radius: 2px;
  margin-top: 10px;
  overflow: hidden;
}

.category-card .mastery-progress {
  height: 100%;
  border-radius: 2px;
  transition: width 0.5s ease;
  width: 0%;
}

.category-card .cat-premium-corner {
  position: absolute;
  top: 8px;
  right: 8px;
  font-size: 12px;
  background: linear-gradient(135deg, #FFD700, #FFA500);
  color: white;
  padding: 2px 10px;
  border-radius: 12px;
  font-weight: 700;
}

.category-card.locked {
  opacity: 0.55;
  pointer-events: none;
}

/* ============================================
   FLASHCARDS PAGE
   ============================================ */
.flashcard-container {
  padding: 20px 0;
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 16px;
  max-width: 500px;
  margin: 0 auto;
}

.fc-category-name {
  font-size: 14px;
  font-weight: 600;
  color: var(--text-muted);
  text-align: center;
  margin-bottom: 4px;
}

.flashcard-progress {
  display: flex;
  align-items: center;
  gap: 12px;
  width: 100%;
  justify-content: center;
  font-size: 14px;
  color: var(--text-muted);
}

.flashcard-progress-bar {
  flex: 1;
  max-width: 240px;
  height: 6px;
  background: rgba(255, 255, 255, 0.06);
  border-radius: 3px;
  overflow: hidden;
}

.flashcard-progress-fill {
  height: 100%;
  background: var(--gradient-primary);
  border-radius: 3px;
  transition: width 0.4s ease;
}

.flashcard {
  position: relative;
  width: 100%;
  max-width: 380px;
  aspect-ratio: 3 / 4;
  perspective: 1000px;
  cursor: pointer;
}

.flashcard-flip-label {
  position: absolute;
  top: 10px;
  left: 50%;
  transform: translateX(-50%);
  z-index: 5;
  font-size: 0.85rem;
  font-weight: 800;
  letter-spacing: 0.04em;
  text-transform: uppercase;
  color: var(--accent);
  background: rgba(20, 184, 166, 0.12);
  border: 1px solid rgba(20, 184, 166, 0.35);
  border-radius: 20px;
  padding: 4px 14px;
  pointer-events: none;
}

.flashcard-inner {
  position: relative;
  width: 100%;
  height: 100%;
  transition: transform 0.6s cubic-bezier(0.4, 0, 0.2, 1);
  transform-style: preserve-3d;
}

.flashcard.flipped .flashcard-inner { transform: rotateY(180deg); }

.flashcard-front, .flashcard-back {
  position: absolute;
  width: 100%;
  height: 100%;
  backface-visibility: hidden;
  border-radius: var(--radius-lg);
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  padding: 30px 20px;
  border: 1px solid;
}

.flashcard-front {
  background: var(--brand-card);
  border-color: var(--brand-border);
}

.flashcard-back {
  background: rgb(20, 27, 45);
  border-color: rgba(20, 184, 166, 0.25);
  transform: rotateY(180deg);
}

.flashcard-emoji { font-size: 72px; margin-bottom: 16px; line-height: 1; }

.flashcard-word {
  font-size: 2rem;
  font-weight: 800;
  color: var(--text-heading);
  margin-bottom: 8px;
}

.flashcard-hint {
  font-size: 14px;
  color: var(--text-muted);
}

.fc-translation {
  font-size: 1.5rem;
  font-weight: 700;
  color: var(--accent-teal);
  margin-bottom: 8px;
}

.fc-example {
  font-size: 15px;
  color: var(--text-body);
  font-style: italic;
  margin-bottom: 16px;
  text-align: center;
}

.flashcard-audio-btn {
  background: var(--accent-teal);
  color: #0F172A;
  border: none;
  width: 48px;
  height: 48px;
  border-radius: 50%;
  font-size: 20px;
  cursor: pointer;
  transition: all 0.3s;
  display: flex;
  align-items: center;
  justify-content: center;
}

.flashcard-audio-btn:hover {
  transform: scale(1.1);
  box-shadow: 0 0 20px rgba(20, 184, 166, 0.3);
}

.flashcard-actions {
  display: flex;
  gap: 12px;
  width: 100%;
  max-width: 380px;
}

.flashcard-action-btn {
  flex: 1;
  padding: 16px;
  border: none;
  border-radius: var(--radius-md);
  font-size: 16px;
  font-weight: 700;
  cursor: pointer;
  transition: all 0.3s;
  font-family: var(--font-family);
}

.flashcard-action-btn:active { transform: scale(0.95); }

.flashcard-action-btn.knew {
  background: var(--accent-correct);
  color: white;
}

.flashcard-action-btn.knew:hover {
  box-shadow: 0 4px 15px rgba(34, 197, 94, 0.3);
}

.flashcard-action-btn.didnt {
  background: var(--accent-wrong);
  color: white;
}

.flashcard-action-btn.didnt:hover {
  box-shadow: 0 4px 15px rgba(239, 68, 68, 0.3);
}

/* ============================================
   QUIZ PAGE
   ============================================ */
.quiz-container {
  padding: 20px 0;
  display: flex;
  flex-direction: column;
  gap: 20px;
  max-width: 500px;
  margin: 0 auto;
}

.quiz-header {
  text-align: center;
}

.quiz-header .quiz-question-num {
  font-size: 14px;
  color: var(--text-muted);
  margin-bottom: 4px;
}

.quiz-header .quiz-word {
  font-size: 1.75rem;
  font-weight: 800;
  color: var(--text-heading);
}

.quiz-header .quiz-emoji { font-size: 56px; margin: 8px 0; }

.quiz-prompt {
  font-size: 14px;
  color: var(--text-muted);
  margin-top: 4px;
}

.quiz-options {
  display: flex;
  flex-direction: column;
  gap: 10px;
}

.quiz-option {
  padding: 16px 20px;
  background: var(--brand-card);
  border: 1px solid var(--brand-border);
  border-radius: var(--radius-md);
  font-size: 16px;
  font-weight: 500;
  cursor: pointer;
  transition: all 0.3s;
  text-align: left;
  font-family: var(--font-family);
  color: var(--text-body);
}

.quiz-option:hover {
  border-color: var(--accent-teal);
  background: rgba(20, 184, 166, 0.05);
  color: var(--text-heading);
}

.quiz-option:active { transform: scale(0.98); }

.quiz-option.correct {
  border-color: var(--accent-correct);
  background: rgba(34, 197, 94, 0.1);
  color: var(--accent-correct);
}

.quiz-option.wrong {
  border-color: var(--accent-wrong);
  background: rgba(239, 68, 68, 0.1);
  color: var(--accent-wrong);
  animation: shake 0.3s ease;
}

.quiz-option.disabled { pointer-events: none; opacity: 0.65; }

.quiz-result {
  position: fixed;
  top: 0; left: 0; right: 0; bottom: 0;
  background: rgba(0, 0, 0, 0.7);
  display: none;
  align-items: center;
  justify-content: center;
  z-index: 200;
  padding: 20px;
}

.quiz-result.show { display: flex; }

.quiz-result-card {
  background: var(--brand-card);
  backdrop-filter: blur(var(--glass-blur));
  -webkit-backdrop-filter: blur(var(--glass-blur));
  border: 1px solid var(--brand-border);
  border-radius: var(--radius-xl);
  padding: 40px 30px;
  text-align: center;
  max-width: 380px;
  width: 100%;
  animation: pop 0.4s ease;
}

.quiz-result-card .result-emoji { font-size: 64px; margin-bottom: 12px; }

.quiz-result-card .result-score {
  font-size: 3rem;
  font-weight: 800;
  color: var(--accent-teal);
}

.quiz-result-card .result-label {
  font-size: 16px;
  color: var(--text-muted);
  margin-bottom: 20px;
}

.quiz-result-card .result-btn {
  background: var(--gradient-primary);
  color: #0F172A;
  border: none;
  padding: 14px 32px;
  border-radius: 50px;
  font-size: 16px;
  font-weight: 700;
  cursor: pointer;
  transition: all 0.3s;
  font-family: var(--font-family);
}

.quiz-result-card .result-btn:hover {
  box-shadow: 0 8px 25px rgba(20, 184, 166, 0.25);
}

/* ============================================
   MATCHING GAME
   ============================================ */
.matching-container {
  padding: 16px 0;
  display: flex;
  flex-direction: column;
  gap: 16px;
  max-width: 600px;
  margin: 0 auto;
}

.matching-title {
  text-align: center;
  font-weight: 700;
  font-size: 1.125rem;
  color: var(--text-heading);
}

.matching-stats {
  display: flex;
  justify-content: center;
  gap: 24px;
  font-size: 14px;
  color: var(--text-muted);
}

.matching-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 10px;
}

.matching-card {
  padding: 20px 12px;
  background: var(--brand-card);
  border: 1px solid var(--brand-border);
  border-radius: var(--radius-md);
  text-align: center;
  font-size: 16px;
  font-weight: 600;
  cursor: pointer;
  transition: all 0.3s;
  min-height: 80px;
  display: flex;
  align-items: center;
  justify-content: center;
  user-select: none;
  color: var(--text-body);
}

.matching-card:hover {
  border-color: var(--accent-teal);
  color: var(--text-heading);
}

.matching-card.selected {
  border-color: var(--accent-teal);
  background: rgba(20, 184, 166, 0.1);
  color: var(--accent-teal);
  transform: scale(1.03);
}

.matching-card.matched {
  animation: matchCorrectPulse 0.4s ease;
  border-color: var(--accent-gold);
  background: rgba(255, 215, 0, 0.08);
  color: var(--accent-gold);
  pointer-events: none;
  opacity: 0.7;
}

.matching-card.wrong {
  animation: shake 0.3s ease;
  border-color: var(--accent-wrong);
  background: rgba(239, 68, 68, 0.08);
  color: var(--accent-wrong);
}

/* ============================================
   PROGRESS PAGE
   ============================================ */
.progress-container {
  padding: 20px 0 30px;
  max-width: 600px;
  margin: 0 auto;
}

.progress-header {
  text-align: center;
  margin-bottom: 24px;
}

.level-badge {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  background: var(--gradient-primary);
  color: #0F172A;
  padding: 10px 24px;
  border-radius: 50px;
  font-size: 18px;
  font-weight: 700;
}

.progress-stats {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 10px;
  margin-bottom: 24px;
}

.stat-card {
  background: var(--brand-card);
  border: 1px solid var(--brand-border);
  border-radius: var(--radius-md);
  padding: 16px;
  text-align: center;
  transition: border-color 0.2s;
}

.stat-card:hover {
  border-color: rgba(20, 184, 166, 0.3);
}

.stat-card .stat-number {
  font-size: 1.5rem;
  font-weight: 800;
  color: var(--accent-teal);
}

.stat-card .stat-label {
  font-size: 11px;
  color: var(--text-muted);
  margin-top: 4px;
}

.progress-section-title {
  font-size: 1.125rem;
  font-weight: 700;
  color: var(--text-heading);
  margin-bottom: 12px;
}

.progress-category-list {
  display: flex;
  flex-direction: column;
  gap: 10px;
}

.progress-category-item {
  background: var(--brand-card);
  border: 1px solid var(--brand-border);
  border-radius: var(--radius-md);
  padding: 14px 16px;
  display: flex;
  align-items: center;
  gap: 12px;
}

.progress-category-item .pci-icon { font-size: 24px; }

.progress-category-item .pci-info { flex: 1; min-width: 0; }

.progress-category-item .pci-name {
  font-size: 14px;
  font-weight: 600;
  color: var(--text-heading);
}

.progress-category-item .pci-mastery {
  font-size: 12px;
  color: var(--text-muted);
}

.progress-category-item .pci-bar {
  height: 6px;
  background: rgba(255, 255, 255, 0.06);
  border-radius: 3px;
  flex: 0 0 100px;
  overflow: hidden;
}

.progress-category-item .pci-fill {
  height: 100%;
  border-radius: 3px;
  transition: width 0.5s ease;
}

/* ============================================
   MODE PICKER
   ============================================ */
.mode-picker-overlay {
  position: fixed;
  top: 0; left: 0; right: 0; bottom: 0;
  background: rgba(0, 0, 0, 0.7);
  display: none;
  align-items: flex-end;
  justify-content: center;
  z-index: 300;
  padding: 20px;
}

.mode-picker-overlay.show { display: flex; }

.mode-picker-card {
  background: var(--brand-card);
  backdrop-filter: blur(var(--glass-blur));
  -webkit-backdrop-filter: blur(var(--glass-blur));
  border: 1px solid var(--brand-border);
  border-radius: 20px 20px 0 0;
  padding: 30px 24px 24px;
  max-width: 440px;
  width: 100%;
  animation: slideUp 0.3s ease;
  text-align: center;
}

.mp-title {
  font-size: 1.25rem;
  font-weight: 700;
  color: var(--text-heading);
  margin-bottom: 4px;
}

.mp-desc {
  font-size: 14px;
  color: var(--text-muted);
  margin-bottom: 20px;
}

.mode-options {
  display: flex;
  flex-direction: column;
  gap: 10px;
  margin-bottom: 16px;
}

.mode-option {
  display: flex;
  align-items: center;
  gap: 14px;
  padding: 16px;
  background: rgba(20, 27, 45, 0.5);
  border: 1px solid var(--brand-border);
  border-radius: var(--radius-md);
  cursor: pointer;
  transition: all 0.3s;
  text-align: left;
  font-family: var(--font-family);
  width: 100%;
}

.mode-option:hover {
  border-color: var(--accent-teal);
  background: rgba(20, 184, 166, 0.05);
}

.mode-option:active { transform: scale(0.98); }

.mode-option .mo-icon { font-size: 32px; }

.mode-option .mo-name {
  font-size: 16px;
  font-weight: 600;
  color: var(--text-heading);
}

.mode-option .mo-desc {
  font-size: 13px;
  color: var(--text-muted);
}

.mode-close-btn {
  background: none;
  border: 1px solid var(--brand-border);
  padding: 12px;
  border-radius: var(--radius-md);
  font-size: 15px;
  font-weight: 600;
  cursor: pointer;
  width: 100%;
  font-family: var(--font-family);
  color: var(--text-muted);
  transition: all 0.3s;
}

.mode-close-btn:hover {
  border-color: var(--text-muted);
  color: var(--text-heading);
}

/* ============================================
   PREMIUM MODAL
   ============================================ */
.premium-overlay {
  position: fixed;
  top: 0; left: 0; right: 0; bottom: 0;
  background: rgba(0, 0, 0, 0.7);
  display: none;
  align-items: center;
  justify-content: center;
  z-index: 400;
  padding: 20px;
}

.premium-overlay.show { display: flex; }

.premium-modal {
  background: var(--brand-card);
  backdrop-filter: blur(var(--glass-blur));
  -webkit-backdrop-filter: blur(var(--glass-blur));
  border: 1px solid var(--brand-border);
  border-radius: 20px;
  max-width: 440px;
  width: 100%;
  max-height: 90vh;
  overflow-y: auto;
  padding: 32px 24px 24px;
  position: relative;
  animation: pop 0.4s ease;
}

.premium-close {
  position: absolute;
  top: 12px; right: 12px;
  background: none;
  border: none;
  font-size: 20px;
  cursor: pointer;
  color: var(--text-muted);
  width: 36px;
  height: 36px;
  display: flex;
  align-items: center;
  justify-content: center;
  border-radius: 50%;
  transition: all 0.3s;
}

.premium-close:hover {
  background: rgba(255, 255, 255, 0.05);
  color: var(--text-heading);
}

.premium-header { text-align: center; margin-bottom: 24px; }

.premium-icon { font-size: 48px; margin-bottom: 8px; }

.premium-title {
  font-size: 1.5rem;
  font-weight: 800;
  color: var(--text-heading);
}

.premium-subtitle {
  font-size: 14px;
  color: var(--text-muted);
  margin-top: 4px;
}

.premium-plans {
  display: flex;
  flex-direction: column;
  gap: 10px;
  margin-bottom: 20px;
}

.premium-plan {
  padding: 16px;
  border: 1px solid var(--brand-border);
  border-radius: var(--radius-md);
  cursor: pointer;
  transition: all 0.3s;
  position: relative;
  font-family: var(--font-family);
  text-align: left;
  background: rgba(20, 27, 45, 0.5);
}

.premium-plan:hover {
  border-color: var(--accent-teal);
}

.premium-plan.active {
  border-color: var(--accent-teal);
  background: rgba(20, 184, 166, 0.08);
}

.premium-plan .pp-name {
  font-size: 16px;
  font-weight: 700;
  color: var(--text-heading);
  margin-bottom: 4px;
}

.premium-plan .pp-price {
  font-size: 14px;
  color: var(--text-muted);
}

.premium-plan .pp-amount {
  font-size: 1.5rem;
  font-weight: 800;
  color: var(--text-heading);
}

.premium-plan .pp-desc {
  font-size: 13px;
  color: var(--text-muted);
  margin-top: 4px;
}

.premium-plan .pp-save {
  color: var(--accent-teal);
  font-weight: 700;
}

/* Match game visual feedback animations */
@keyframes matchCorrectPulse {
  0% { transform: scale(1); }
  50% { transform: scale(1.04); }
  100% { transform: scale(1); }
}
@keyframes matchWrongShake {
  0%, 100% { transform: translateX(0); }
  20% { transform: translateX(-6px); }
  40% { transform: translateX(6px); }
  60% { transform: translateX(-4px); }
  80% { transform: translateX(4px); }
}
.match-item.matched-correct { animation: matchCorrectPulse 0.4s ease; }
.match-item.matched-wrong { animation: matchWrongShake 0.4s ease; }

.premium-plan .pp-popular {
  position: absolute;
  top: -8px; right: 12px;
  font-size: 11px;
  font-weight: 700;
  background: linear-gradient(135deg, #FFD700, #FFA500);
  color: #0F172A;
  padding: 3px 10px;
  border-radius: 20px;
}

.premium-plan .pp-badge {
  position: absolute;
  bottom: -8px; left: 50%;
  transform: translateX(-50%);
  font-size: 10px;
  font-weight: 700;
  background: linear-gradient(135deg, #10B981, #059669);
  color: #FFFFFF;
  padding: 2px 12px;
  border-radius: 20px;
  white-space: nowrap;
}

.premium-features { margin-bottom: 20px; }

.premium-features .pf-item {
  padding: 6px 0;
  font-size: 14px;
  color: var(--text-body);
}

.premium-subscribe {
  width: 100%;
  padding: 16px;
  background: var(--gradient-primary);
  color: #0F172A;
  border: none;
  border-radius: var(--radius-md);
  font-size: 18px;
  font-weight: 700;
  cursor: pointer;
  transition: all 0.3s;
  font-family: var(--font-family);
}

.premium-subscribe:hover {
  box-shadow: 0 8px 25px rgba(20, 184, 166, 0.25);
  transform: translateY(-2px);
}

.premium-subscribe:active { transform: translateY(0); }

.premium-subscribe.loading {
  opacity: 0.7;
  pointer-events: none;
}

.premium-backend-status {
  text-align: center;
  margin-top: 10px;
  font-size: 12px;
  color: var(--text-muted);
}

/* ============================================
   PREMIUM LOCK OVERLAY
   ============================================ */
.premium-lock-overlay {
  position: fixed;
  top: 0; left: 0; right: 0; bottom: 0;
  background: rgba(0, 0, 0, 0.7);
  display: none;
  align-items: center;
  justify-content: center;
  z-index: 350;
  padding: 20px;
}

.premium-lock-overlay.show { display: flex; }

.premium-lock-modal {
  background: var(--brand-card);
  backdrop-filter: blur(var(--glass-blur));
  -webkit-backdrop-filter: blur(var(--glass-blur));
  border: 1px solid var(--brand-border);
  border-radius: 20px;
  padding: 36px 28px;
  max-width: 380px;
  width: 100%;
  text-align: center;
  animation: pop 0.4s ease;
}

.premium-lock-modal .pl-icon { font-size: 64px; margin-bottom: 12px; }

.premium-lock-modal .pl-title {
  font-size: 1.5rem;
  font-weight: 800;
  color: var(--text-heading);
  margin-bottom: 8px;
}

.premium-lock-modal .pl-desc {
  font-size: 15px;
  color: var(--text-muted);
  margin-bottom: 24px;
  line-height: 1.6;
}

.premium-lock-modal .pl-btn {
  display: block;
  width: 100%;
  padding: 14px;
  background: var(--gradient-primary);
  color: #0F172A;
  border: none;
  border-radius: var(--radius-md);
  font-size: 16px;
  font-weight: 700;
  cursor: pointer;
  margin-bottom: 10px;
  transition: all 0.3s;
  font-family: var(--font-family);
}

.premium-lock-modal .pl-btn:hover {
  box-shadow: 0 8px 25px rgba(20, 184, 166, 0.25);
  transform: translateY(-2px);
}

.premium-lock-modal .pl-cancel {
  display: block;
  width: 100%;
  padding: 12px;
  background: none;
  border: 1px solid var(--brand-border);
  border-radius: var(--radius-md);
  font-size: 15px;
  font-weight: 600;
  color: var(--text-muted);
  cursor: pointer;
  transition: all 0.3s;
  font-family: var(--font-family);
}

.premium-lock-modal .pl-cancel:hover {
  border-color: var(--text-muted);
  color: var(--text-heading);
}

/* ============================================
   CONFETTI
   ============================================ */
.confetti-piece {
  position: fixed;
  width: 10px;
  height: 10px;
  animation: confetti-fall 1.5s ease forwards;
  border-radius: 2px;
  z-index: 500;
  pointer-events: none;
}

/* ============================================
   TOAST
   ============================================ */
.toast {
  position: fixed;
  bottom: 30px;
  left: 50%;
  transform: translateX(-50%);
  background: var(--brand-card);
  backdrop-filter: blur(var(--glass-blur));
  -webkit-backdrop-filter: blur(var(--glass-blur));
  border: 1px solid var(--brand-border);
  color: var(--text-heading);
  padding: 14px 28px;
  border-radius: 50px;
  font-weight: 600;
  z-index: 600;
  animation: slideUp 0.3s ease;
  box-shadow: 0 8px 30px rgba(0, 0, 0, 0.3);
  max-width: 90%;
  text-align: center;
  display: none;
}

/* ============================================
   RESPONSIVE
   ============================================ */

/* Tablet & below */
@media (max-width: 768px) {
  .categories-grid {
    grid-template-columns: repeat(auto-fill, minmax(160px, 1fr));
  }

  .dash-stats {
    grid-template-columns: repeat(2, 1fr);
  }

  .progress-stats {
    grid-template-columns: repeat(2, 1fr);
  }

  .matching-grid {
    gap: 8px;
  }

  .matching-card {
    font-size: 14px;
    padding: 16px 8px;
    min-height: 70px;
  }

  .flashcard-emoji { font-size: 56px; }
  .flashcard-word { font-size: 1.5rem; }

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

/* Mobile */
@media (max-width: 480px) {
  .app-header {
    padding: 0.625rem 1rem;
  }

  .app-header .logo {
    font-size: 18px;
  }

  .header-xp {
    font-size: 12px;
    padding: 4px 10px;
  }

  .categories-grid {
    grid-template-columns: 1fr 1fr;
    gap: 10px;
  }

  .category-card {
    padding: 16px;
  }

  .category-card .cat-icon { font-size: 28px; }

  .dash-greeting .dash-hello {
    font-size: 1.375rem;
  }

  .dash-qa-btn {
    padding: 14px 12px;
    font-size: 13px;
  }

  .flashcard-emoji { font-size: 48px; }
  .flashcard-word { font-size: 1.25rem; }

  .flashcard-actions {
    flex-direction: column;
    gap: 8px;
  }

  .matching-card {
    font-size: 13px;
    padding: 12px 6px;
    min-height: 60px;
  }

  .dash-stat-num {
    font-size: 1.25rem;
  }

  .stat-card .stat-number {
    font-size: 1.25rem;
  }

  .premium-modal {
    padding: 24px 16px 20px;
  }

  .welcome-container {
    padding: 40px 16px;
  }

  .welcome-title {
    font-size: 1.5rem;
  }

  .progress-category-item .pci-bar {
    flex: 0 0 60px;
  }
}

/* Desktop large screens — side borders like lesson pages */
@media (min-width: 1200px) {
  .app-container {
    border-left: 1px solid var(--brand-border);
    border-right: 1px solid var(--brand-border);
    box-shadow: 0 0 40px rgba(0, 0, 0, 0.15);
  }
}

/* ============================================
   WELCOME PAGE — LANGUAGE SELECTOR
   ============================================ */
.welcome-lang-section {
  margin: 24px auto 0;
  width: 100%;
  max-width: 680px;
  text-align: center;
}

.welcome-lang-label {
  font-size: 0.85rem;
  color: var(--text-muted);
  margin-bottom: 12px;
}

.welcome-lang-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(130px, 1fr));
  gap: 10px;
  margin-bottom: 20px;
  width: 100%;
}

.welcome-lang-btn {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 4px;
  padding: 12px 8px;
  border-radius: 12px;
  border: 1px solid var(--brand-border);
  background: var(--brand-card);
  cursor: pointer;
  transition: all 0.2s;
}

.welcome-lang-btn:hover {
  border-color: var(--brand-accent);
  background: rgba(20, 184, 166, 0.08);
}

.welcome-lang-btn.active {
  border-color: var(--brand-accent);
  background: rgba(20, 184, 166, 0.15);
  box-shadow: 0 0 12px rgba(20, 184, 166, 0.2);
}

.welcome-lang-flag {
  font-size: 1.6rem;
  line-height: 1;
}

.welcome-lang-name {
  font-size: 0.7rem;
  color: var(--text-muted);
  text-align: center;
  line-height: 1.2;
}

.welcome-lang-btn.active .welcome-lang-name {
  color: var(--brand-accent);
}

/* ============================================
   DASHBOARD — LESSON LEVELS
   ============================================ */
.dash-levels {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(160px, 1fr));
  gap: 10px;
  margin-top: 8px;
}

.dash-level-card {
  display: flex;
  align-items: center;
  gap: 10px;
  padding: 14px 16px;
  border-radius: 14px;
  border: 1px solid var(--brand-border);
  background: var(--brand-card);
  cursor: pointer;
  transition: all 0.2s;
}

.dash-level-card:hover {
  border-color: var(--brand-accent);
  background: rgba(20, 184, 166, 0.06);
}

.dash-level-card.locked {
  cursor: not-allowed;
}

.dash-level-dot {
  font-size: 1.3rem;
  flex-shrink: 0;
}

.dash-level-body {
  display: flex;
  flex-direction: column;
  gap: 2px;
  flex: 1;
  min-width: 0;
}

.dash-level-label {
  font-size: 0.85rem;
  font-weight: 600;
  color: var(--text-primary);
  line-height: 1.2;
}

.dash-level-count {
  font-size: 0.7rem;
  color: var(--text-muted);
}

.dash-level-arrow,
.dash-level-lock {
  font-size: 0.9rem;
  flex-shrink: 0;
}

/* ============================================
   LESSONS BROWSER PAGE
   ============================================ */
.lessons-container {
  max-width: 720px;
  margin: 0 auto;
  padding: 20px 0;
}

.lessons-header {
  display: flex;
  flex-direction: column;
  gap: 12px;
  margin-bottom: 24px;
}

.lessons-title {
  font-size: 1.5rem;
  font-weight: 700;
  color: var(--text-primary);
}

.lessons-grid {
  display: flex;
  flex-direction: column;
  gap: 8px;
}

.lesson-card-item {
  display: flex;
  align-items: center;
  gap: 14px;
  padding: 14px 18px;
  border-radius: 14px;
  border: 1px solid var(--brand-border);
  background: var(--brand-card);
  cursor: pointer;
  transition: all 0.2s;
}

.lesson-card-item:hover {
  border-color: var(--brand-accent);
  background: rgba(20, 184, 166, 0.06);
  transform: translateX(4px);
}

.lesson-card-num {
  width: 36px;
  height: 36px;
  border-radius: 50%;
  background: rgba(20, 184, 166, 0.12);
  color: var(--brand-accent);
  font-weight: 700;
  font-size: 0.85rem;
  display: flex;
  align-items: center;
  justify-content: center;
  flex-shrink: 0;
}

.lesson-card-info {
  flex: 1;
  min-width: 0;
}

.lesson-card-title {
  font-size: 0.9rem;
  font-weight: 600;
  color: var(--text-primary);
  white-space: nowrap;
  overflow: hidden;
  text-overflow: ellipsis;
}

.lesson-card-meta {
  font-size: 0.75rem;
  color: var(--text-muted);
  margin-top: 2px;
}

.lesson-card-pct {
  font-size: 0.8rem;
  font-weight: 600;
  color: var(--brand-accent);
  flex-shrink: 0;
}

/* ============================================
   LESSON VIEWER PAGE
   ============================================ */
.lesson-viewer-container {
  max-width: 800px;
  margin: 0 auto;
  padding: 16px 0;
}

.lesson-back-btn {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  padding: 8px 16px;
  border-radius: 10px;
  border: 1px solid var(--brand-border);
  background: var(--brand-card);
  color: var(--text-muted);
  font-size: 0.85rem;
  cursor: pointer;
  transition: all 0.2s;
  margin-bottom: 16px;
}

.lesson-back-btn:hover {
  border-color: var(--brand-accent);
  color: var(--brand-accent);
}

.lesson-nav-bar {
  position: sticky;
  top: 60px;
  z-index: 40;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 10px;
  margin-bottom: 16px;
  padding: 8px 12px;
  border-radius: 12px;
  border: 1px solid var(--brand-border);
  background: rgba(15, 23, 42, 0.85);
  backdrop-filter: blur(8px);
}

.lesson-nav-btn {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  padding: 8px 16px;
  border-radius: 10px;
  border: 1px solid var(--brand-border);
  background: var(--brand-card);
  color: var(--text-primary);
  font-size: 0.85rem;
  font-weight: 600;
  cursor: pointer;
  transition: all 0.2s;
  white-space: nowrap;
}

.lesson-nav-btn:hover {
  border-color: var(--brand-accent);
  color: var(--brand-accent);
}

.lesson-nav-btn .nav-arrow {
  font-size: 1rem;
  line-height: 1;
}

.lesson-viewer-content {
  min-height: 60vh;
}