/* ==========================================================================
   Kanakita - Main Design System & Stylesheet (Japandi Modern & Mobile First)
   ========================================================================== */

:root {
  /* Core Color Tokens */
  --primary: #ff4757;
  --primary-hover: #ff6b81;
  --primary-light: #fff0f3;
  --primary-gradient: linear-gradient(135deg, #ff4757 0%, #ff6b81 100%);
  
  --secondary: #3742fa;
  --secondary-light: #eef2ff;

  --accent-green: #2ed573;
  --accent-green-light: #e6f9ed;
  --accent-gold: #ffa502;
  --accent-purple: #70a1ff;

  --bg-main: #faf7f2;
  --bg-card: #ffffff;
  --bg-glass: rgba(255, 255, 255, 0.88);

  --text-primary: #1e1e24;
  --text-secondary: #57606f;
  --text-muted: #a4b0be;

  --border-light: #f1f2f6;
  --border-medium: #dfe4ea;
  
  --shadow-sm: 0 4px 12px rgba(0, 0, 0, 0.03);
  --shadow-md: 0 10px 30px rgba(0, 0, 0, 0.06);
  --shadow-lg: 0 20px 40px rgba(0, 0, 0, 0.12);
  --shadow-primary: 0 10px 25px rgba(255, 71, 87, 0.3);

  --radius-sm: 10px;
  --radius-md: 16px;
  --radius-lg: 24px;
  --radius-full: 9999px;

  --font-sans: 'Outfit', -apple-system, BlinkMacSystemFont, sans-serif;
  --font-jp: 'Noto Sans JP', sans-serif;
  --transition: all 0.25s cubic-bezier(0.4, 0, 0.2, 1);
}

/* Reset & Basic Styles */
*, *::before, *::after {
  box-sizing: border-box;
  margin: 0;
  padding: 0;
  -webkit-tap-highlight-color: transparent;
}

html {
  scroll-behavior: smooth;
  font-size: 16px;
}

body {
  font-family: var(--font-sans);
  background-color: var(--bg-main);
  color: var(--text-primary);
  line-height: 1.5;
  min-height: 100vh;
  display: flex;
  flex-direction: column;
  overflow-x: hidden;
  padding-bottom: 70px; /* Space for mobile bottom nav */
}

@media (min-width: 769px) {
  body {
    padding-bottom: 0;
  }
}

/* Decorative Background Pattern */
body::before {
  content: '';
  position: fixed;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  background: 
    radial-gradient(circle at 10% 20%, rgba(255, 71, 87, 0.03) 0%, transparent 40%),
    radial-gradient(circle at 90% 80%, rgba(55, 66, 250, 0.03) 0%, transparent 40%);
  pointer-events: none;
  z-index: -1;
}

/* Utility Classes */
.container {
  width: 100%;
  max-width: 1200px;
  margin: 0 auto;
  padding: 0 16px;
}

.badge {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  padding: 4px 12px;
  border-radius: var(--radius-full);
  font-size: 0.825rem;
  font-weight: 600;
}

.badge-primary { background: var(--primary-light); color: var(--primary); }
.badge-secondary { background: var(--secondary-light); color: var(--secondary); }
.badge-success { background: var(--accent-green-light); color: var(--accent-green); }

/* Buttons & Touch Targets (Min 44px for touch accessibility) */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  padding: 12px 22px;
  min-height: 44px;
  border-radius: var(--radius-full);
  font-weight: 700;
  font-size: 0.95rem;
  cursor: pointer;
  transition: var(--transition);
  border: none;
  outline: none;
  user-select: none;
}

.btn-primary {
  background: var(--primary-gradient);
  color: white;
  box-shadow: var(--shadow-primary);
}

.btn-primary:active, .btn-primary:hover {
  transform: translateY(-2px);
  box-shadow: 0 12px 24px rgba(255, 71, 87, 0.4);
}

.btn-secondary {
  background: var(--secondary-light);
  color: var(--secondary);
}

.btn-secondary:active, .btn-secondary:hover {
  background: #e0e7ff;
  transform: translateY(-2px);
}

.btn-outline {
  background: transparent;
  border: 2px solid var(--border-medium);
  color: var(--text-primary);
}

.btn-outline:active, .btn-outline:hover {
  border-color: var(--primary);
  color: var(--primary);
  background: var(--primary-light);
}

/* Header & Navbar */
.navbar {
  position: sticky;
  top: 0;
  z-index: 1000;
  background: var(--bg-glass);
  backdrop-filter: blur(12px);
  border-bottom: 1px solid var(--border-light);
  padding: 10px 0;
  transition: var(--transition);
}

.navbar .container {
  display: flex;
  align-items: center;
  justify-content: space-between;
}

.brand {
  display: flex;
  align-items: center;
  gap: 10px;
  text-decoration: none;
  color: var(--text-primary);
  font-weight: 800;
  font-size: 1.35rem;
}

.brand-icon {
  width: 38px;
  height: 38px;
  background: var(--primary-gradient);
  border-radius: var(--radius-md);
  display: flex;
  align-items: center;
  justify-content: center;
  color: white;
  font-family: var(--font-jp);
  font-size: 1.3rem;
  box-shadow: var(--shadow-primary);
}

.brand-text span {
  color: var(--primary);
}

.nav-links {
  display: flex;
  align-items: center;
  gap: 6px;
  list-style: none;
}

.nav-link {
  padding: 8px 14px;
  border-radius: var(--radius-full);
  text-decoration: none;
  color: var(--text-secondary);
  font-weight: 600;
  font-size: 0.9rem;
  transition: var(--transition);
  cursor: pointer;
  border: none;
  background: transparent;
  white-space: nowrap;
}

.nav-link:hover, .nav-link.active {
  color: var(--primary);
  background: var(--primary-light);
}

.user-nav-actions {
  display: flex;
  align-items: center;
  gap: 8px;
}

.streak-pill {
  display: flex;
  align-items: center;
  gap: 4px;
  background: #fff0db;
  color: var(--accent-gold);
  padding: 6px 12px;
  border-radius: var(--radius-full);
  font-weight: 700;
  font-size: 0.85rem;
  box-shadow: var(--shadow-sm);
  white-space: nowrap;
}

/* Mobile Bottom Navigation Bar */
.mobile-bottom-nav {
  display: none;
  position: fixed;
  bottom: 0;
  left: 0;
  width: 100vw;
  height: 64px;
  background: var(--bg-glass);
  backdrop-filter: blur(16px);
  border-top: 1px solid var(--border-medium);
  z-index: 1500;
  padding: 0 10px;
}

.mobile-bottom-nav-inner {
  display: flex;
  align-items: center;
  justify-content: space-around;
  height: 100%;
}

.mobile-nav-btn {
  flex: 1 1 0;
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  background: none;
  border: none;
  color: var(--text-secondary);
  font-size: 0.65rem;
  font-weight: 600;
  cursor: pointer;
  padding: 4px 2px;
  border-radius: var(--radius-sm);
  transition: var(--transition);
  min-width: 0;
  white-space: nowrap;
}

.mobile-nav-btn .nav-icon {
  font-size: 1.3rem;
  margin-bottom: 2px;
}

img.emoji {
  display: inline-block;
  width: 1em;
  height: 1em;
  margin: 0 0.05em;
  vertical-align: -0.12em;
}

.vocab-search-filter {
  position: relative;
}

.vocab-search-icon {
  position: absolute;
  left: 18px;
  top: 50%;
  transform: translateY(-50%);
}

.mobile-nav-btn.active {
  color: var(--primary);
  font-weight: 800;
}

.mobile-nav-btn.active .nav-icon {
  transform: scale(1.15);
}

/* Hero Section */
.hero-section {
  padding: 20px 0 40px;
}

.hero-card {
  background: var(--bg-card);
  border-radius: var(--radius-lg);
  box-shadow: var(--shadow-md);
  padding: 32px 28px;
  display: flex;
  flex-direction: column;
  border: 1px solid var(--border-light);
  position: relative;
  overflow: hidden;
}

.hero-content h1 {
  font-size: clamp(1.8rem, 4vw, 2.8rem);
  line-height: 1.25;
  font-weight: 800;
  margin-bottom: 14px;
  color: var(--text-primary);
}

.hero-content h1 span {
  color: var(--primary);
}

.hero-content p {
  font-size: 1rem;
  color: var(--text-secondary);
  margin-bottom: 24px;
}

.hero-actions {
  display: flex;
  gap: 12px;
  flex-wrap: wrap;
}

.hero-image-wrapper {
  position: relative;
  border-radius: var(--radius-md);
  overflow: hidden;
  box-shadow: var(--shadow-md);
  transition: transform 0.3s ease, box-shadow 0.3s ease;
}

.hero-image-wrapper:hover {
  transform: translateY(-3px);
  box-shadow: var(--shadow-lg);
}

.hero-banner-img {
  width: 100%;
  max-width: 100%;
  height: auto;
  display: block;
  border-radius: var(--radius-md);
  object-fit: cover;
}

/* Main Content Area */
.app-content {
  padding-bottom: 40px;
  flex: 1;
}

.tab-pane {
  display: none;
  animation: fadeIn 0.3s ease-out;
}

.tab-pane.active {
  display: block;
}

#tab-kuis.quiz-menu-centered.active {
  display: flex;
  align-items: center;
  justify-content: center;
  min-height: calc(100dvh - 160px);
}

@keyframes fadeIn {
  from { opacity: 0; transform: translateY(8px); }
  to { opacity: 1; transform: translateY(0); }
}

/* Section Headers */
.section-header {
  margin-bottom: 24px;
  display: flex;
  align-items: flex-end;
  justify-content: space-between;
  flex-wrap: wrap;
  gap: 16px;
}

.section-title-group h2 {
  font-size: clamp(1.4rem, 3vw, 2rem);
  font-weight: 800;
  color: var(--text-primary);
}

.section-title-group p {
  color: var(--text-secondary);
  font-size: 0.95rem;
}

/* Filter Controls */
.filter-bar {
  display: flex;
  align-items: center;
  gap: 8px;
  flex-wrap: wrap;
  background: var(--bg-card);
  padding: 6px;
  border-radius: var(--radius-full);
  box-shadow: var(--shadow-sm);
  border: 1px solid var(--border-light);
  width: 100%;
  max-width: fit-content;
}

.kana-system-filter {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  flex-wrap: nowrap;
  width: 100%;
  max-width: 520px;
}

.kana-system-filter .filter-btn {
  min-width: 0;
  padding-inline: 6px;
  white-space: nowrap;
}

.filter-btn {
  padding: 8px 16px;
  min-height: 38px;
  border-radius: var(--radius-full);
  border: none;
  background: transparent;
  font-weight: 600;
  font-size: 0.875rem;
  color: var(--text-secondary);
  cursor: pointer;
  transition: var(--transition);
  flex: 1;
  text-align: center;
}

.filter-btn.active {
  background: var(--primary-gradient);
  color: white;
  box-shadow: var(--shadow-primary);
}

.category-filter-bar {
  display: flex;
  gap: 6px;
  flex-wrap: wrap;
}

.filter-pill {
  padding: 6px 12px;
  font-size: 0.78rem;
  border-radius: var(--radius-full);
  border: 1px solid var(--border-medium);
  background: white;
  color: var(--text-secondary);
  font-weight: 600;
  cursor: pointer;
  transition: all 0.2s ease;
  box-shadow: 0 1px 3px rgba(0,0,0,0.04);
}

.filter-pill:hover {
  border-color: var(--primary);
  color: var(--primary);
}

.filter-pill.active {
  background: var(--primary-light);
  color: var(--primary);
  border-color: var(--primary);
  font-weight: 700;
}

.sound-group-filter-bar {
  display: flex;
  gap: 4px;
  flex-wrap: wrap;
}

.sound-pill {
  padding: 3px 8px;
  font-size: 0.7rem;
  border-radius: var(--radius-sm);
  border: 1px solid var(--border-light);
  background: var(--bg-main);
  color: var(--text-secondary);
  font-weight: 600;
  cursor: pointer;
  transition: all 0.2s ease;
}

.sound-pill:hover {
  background: white;
  border-color: var(--primary);
  color: var(--primary);
}

.sound-pill.active {
  background: var(--primary);
  color: white;
  border-color: var(--primary);
  font-weight: 700;
}

/* Categorized Sound Group Containers */
.kana-sound-group {
  margin-bottom: 20px;
  background: var(--bg-card);
  border-radius: var(--radius-md);
  padding: 16px;
  border: 1px solid var(--border-medium);
  box-shadow: 0 2px 8px rgba(0, 0, 0, 0.02);
}

.kana-sound-group-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  margin-bottom: 12px;
  padding-bottom: 8px;
  border-bottom: 2px dashed var(--border-medium);
}

.kana-sound-group-title {
  font-size: 1rem;
  font-weight: 800;
  color: var(--text-primary);
  display: flex;
  align-items: center;
  gap: 6px;
}

.kana-sound-group-badge {
  font-size: 0.72rem;
  background: var(--primary-light);
  color: var(--primary);
  padding: 2px 8px;
  border-radius: var(--radius-full);
  font-weight: 700;
}

/* Kana Grid Section (Responsive layout for Kana Grid) */
/* Outer container holds .kana-sound-group sections stacked vertically */
.kana-grid-container {
  display: flex;
  flex-direction: column;
  gap: 0;
}

/* The actual card grid inside each sound group */
.kana-sound-group .kana-grid-container {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(100px, 1fr));
  gap: 12px;
  flex-direction: unset;
}

.kana-card {
  background: var(--bg-card);
  border-radius: var(--radius-md);
  padding: 12px 8px;
  text-align: center;
  box-shadow: var(--shadow-sm);
  border: 2px solid var(--border-light);
  cursor: pointer;
  transition: var(--transition);
  position: relative;
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  min-height: 110px;
}

.kana-card:active, .kana-card:hover {
  transform: translateY(-4px);
  border-color: var(--primary);
  box-shadow: var(--shadow-md);
}

.kana-card.mastered {
  border-color: var(--accent-green);
  background: var(--accent-green-light);
}

.kana-card .mastered-check {
  position: absolute;
  top: 4px;
  right: 6px;
  font-size: 0.725rem;
  color: var(--accent-green);
  font-weight: 800;
}

.kana-char {
  font-family: var(--font-jp);
  font-size: 2.2rem;
  font-weight: 700;
  color: var(--text-primary);
  line-height: 1.1;
  margin-bottom: 2px;
}

.kana-romaji {
  font-size: 0.85rem;
  font-weight: 700;
  color: var(--text-secondary);
  text-transform: lowercase;
}

.fluent-emoji-3d {
  display: inline-block;
  width: 1em;
  height: 1em;
  object-fit: contain;
  vertical-align: -0.15em;
}

.audio-btn-icon {
  margin-top: 4px;
  font-size: 0.75rem;
  color: var(--text-muted);
}

/* Character Detail Modal (Mobile Responsive) */
.modal-overlay {
  position: fixed;
  top: 0;
  left: 0;
  width: 100vw;
  height: 100vh;
  background: rgba(30, 30, 36, 0.65);
  backdrop-filter: blur(6px);
  z-index: 2000;
  display: flex;
  align-items: center;
  justify-content: center;
  opacity: 0;
  pointer-events: none;
  transition: var(--transition);
  padding: 12px;
}

.modal-overlay.active {
  opacity: 1;
  pointer-events: auto;
}

.modal-content {
  background: var(--bg-card);
  border-radius: var(--radius-lg);
  max-width: 650px;
  width: 100%;
  max-height: 92vh;
  overflow-y: auto;
  box-shadow: var(--shadow-lg);
  position: relative;
  transform: scale(0.95);
  transition: var(--transition);
  padding: 24px 20px;
  -webkit-overflow-scrolling: touch;
}

.modal-overlay.active .modal-content {
  transform: scale(1);
}

.auth-password-control {
  display: flex;
  align-items: center;
  gap: 8px;
}

.auth-password-control input {
  flex: 1;
  min-width: 0;
}

.auth-password-toggle {
  flex: 0 0 auto;
  padding: 8px 4px;
  border: 0;
  background: transparent;
  color: var(--primary);
  font: inherit;
  font-size: 0.85rem;
  font-weight: 700;
  white-space: nowrap;
  cursor: pointer;
}

.auth-password-toggle:focus-visible {
  outline: 2px solid var(--primary);
  outline-offset: 2px;
  border-radius: var(--radius-sm);
}

.modal-close-btn {
  position: absolute;
  top: 16px;
  right: 16px;
  background: var(--border-light);
  border: none;
  width: 36px;
  height: 36px;
  border-radius: var(--radius-full);
  font-size: 1.1rem;
  cursor: pointer;
  display: flex;
  align-items: center;
  justify-content: center;
  color: var(--text-secondary);
  transition: var(--transition);
  z-index: 10;
}

.modal-kana-header {
  display: flex;
  align-items: center;
  gap: 16px;
  margin-bottom: 16px;
  padding-bottom: 16px;
  border-bottom: 1px solid var(--border-light);
}

.modal-kana-char {
  font-family: var(--font-jp);
  font-size: clamp(3rem, 10vw, 4.5rem);
  font-weight: 800;
  color: var(--primary);
  line-height: 1;
}

.modal-kana-info h3 {
  font-size: 1.4rem;
  font-weight: 800;
}

/* Stroke Order & Canvas Layout */
.stroke-canvas-layout {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 16px;
  margin: 16px 0;
}

@media (max-width: 600px) {
  .stroke-canvas-layout {
    grid-template-columns: 1fr;
  }
}

.stroke-box, .canvas-box {
  background: var(--bg-main);
  border-radius: var(--radius-md);
  padding: 12px;
  text-align: center;
  border: 1px solid var(--border-medium);
  box-shadow: 0 2px 8px rgba(0, 0, 0, 0.03);
}

.video-player-card {
  display: flex;
  flex-direction: column;
  align-items: center;
}

.stroke-player-header {
  width: 100%;
  display: flex;
  justify-content: space-between;
  align-items: center;
  margin-bottom: 8px;
}

.stroke-speed-select {
  padding: 2px 6px;
  font-size: 0.72rem;
  border-radius: 6px;
  border: 1px solid var(--border-medium);
  background: white;
  color: var(--text-primary);
  font-weight: 600;
  cursor: pointer;
}

.stroke-anim-stage {
  position: relative;
  width: 150px;
  height: 150px;
  background: #ffffff;
  border-radius: var(--radius-sm);
  border: 2px solid #e2e8f0;
  margin: 0 auto;
  overflow: hidden;
  box-shadow: inset 0 0 8px rgba(0, 0, 0, 0.02);
}

.stroke-animation-svg {
  width: 100%;
  height: 100%;
}

.stroke-reference-gif {
  display: block;
  width: 100%;
  height: 100%;
  object-fit: contain;
}

.stroke-source-link {
  margin-top: 6px;
  color: var(--text-secondary);
  font-size: 0.7rem;
  text-align: center;
}

.stroke-video-timeline-bar {
  width: 100%;
  margin-top: 8px;
  padding: 0 4px;
}

.stroke-video-timeline-bar input[type="range"] {
  width: 100%;
  height: 4px;
  accent-color: var(--primary);
  cursor: pointer;
}

.stroke-video-controls {
  display: flex;
  gap: 8px;
  align-items: center;
  justify-content: center;
  margin-top: 8px;
}

.stroke-ctrl-btn {
  width: 32px;
  height: 32px;
  border-radius: 50%;
  border: 1px solid var(--border-medium);
  background: white;
  color: var(--text-primary);
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 0.85rem;
  cursor: pointer;
  transition: all 0.2s ease;
}

.stroke-ctrl-btn:hover {
  background: var(--primary-light);
  color: var(--primary);
  border-color: var(--primary);
  transform: scale(1.05);
}

.stroke-ctrl-btn.play-btn {
  width: 36px;
  height: 36px;
  background: var(--primary);
  color: white;
  border: none;
  font-size: 1rem;
  box-shadow: 0 2px 6px rgba(255, 71, 87, 0.3);
}

.stroke-ctrl-btn.play-btn:hover {
  background: #ff3344;
  transform: scale(1.08);
}

.canvas-wrapper {
  position: relative;
  width: 150px;
  height: 150px;
  margin: 0 auto;
}

.writing-canvas-element {
  background: white;
  border-radius: var(--radius-sm);
  border: 2px solid #cbd5e1;
  cursor: crosshair;
  touch-action: none;
  width: 100%;
  height: 100%;
}

.canvas-actions {
  display: flex;
  gap: 6px;
  margin-top: 8px;
  justify-content: center;
}

  background: var(--bg-main);
  border-radius: var(--radius-sm);
  margin-bottom: 8px;
}

.vocab-japanese {
  font-family: var(--font-jp);
  font-size: 1.1rem;
  font-weight: 700;
}

.vocab-romaji {
  font-size: 0.85rem;
  color: var(--text-muted);
}

/* Flashcard Module (Mobile Optimized) */
.flashcard-section {
  max-width: 480px;
  margin: 0 auto;
  text-align: center;
}

.flashcard-scene {
  width: 100%;
  height: 280px;
  perspective: 1000px;
  margin-bottom: 20px;
  cursor: pointer;
}

.flashcard-object {
  width: 100%;
  height: 100%;
  position: relative;
  transform-style: preserve-3d;
  transition: transform 0.5s cubic-bezier(0.4, 0, 0.2, 1);
}

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

.flashcard-face {
  position: absolute;
  width: 100%;
  height: 100%;
  backface-visibility: hidden;
  border-radius: var(--radius-lg);
  box-shadow: var(--shadow-md);
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  padding: 24px;
  border: 2px solid var(--border-light);
}

.flashcard-front { background: var(--bg-card); }
.flashcard-back {
  background: var(--primary-light);
  transform: rotateY(180deg);
  border-color: var(--primary-hover);
}

.flashcard-char {
  font-family: var(--font-jp);
  font-size: 5rem;
  font-weight: 800;
  color: var(--primary);
  line-height: 1;
}

/* Quiz Module */
.quiz-container {
  max-width: 600px;
  margin: 0 auto;
  background: var(--bg-card);
  border-radius: var(--radius-lg);
  padding: 24px 18px;
  box-shadow: var(--shadow-md);
  border: 1px solid var(--border-light);
}

.quiz-header-bar {
  display: flex;
  align-items: center;
  justify-content: space-between;
  margin-bottom: 16px;
}

.timer-badge {
  background: var(--primary-light);
  color: var(--primary);
  padding: 4px 12px;
  border-radius: var(--radius-full);
  font-weight: 800;
  font-size: 0.9rem;
}

.quiz-progress-track {
  width: 100%;
  height: 6px;
  background: var(--border-light);
  border-radius: var(--radius-full);
  overflow: hidden;
  margin-bottom: 24px;
}

.quiz-progress-fill {
  height: 100%;
  background: var(--primary-gradient);
  transition: width 0.3s ease;
}

.quiz-question-box {
  text-align: center;
  margin-bottom: 24px;
}

.quiz-question-char {
  font-family: var(--font-jp);
  font-size: 4rem;
  font-weight: 800;
  color: var(--text-primary);
  line-height: 1;
  margin: 8px 0;
}

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

.quiz-option-btn {
  padding: 14px;
  min-height: 48px;
  background: var(--bg-main);
  border: 2px solid var(--border-medium);
  border-radius: var(--radius-md);
  font-size: 1.1rem;
  font-weight: 700;
  cursor: pointer;
  transition: var(--transition);
  color: var(--text-primary);
}

.quiz-option-btn.correct {
  background: var(--accent-green-light) !important;
  border-color: var(--accent-green) !important;
  color: var(--accent-green) !important;
}

.quiz-option-btn.wrong {
  background: #ffe5e5 !important;
  border-color: var(--primary) !important;
  color: var(--primary) !important;
}

/* Profile Section */
.profile-grid {
  display: grid;
  grid-template-columns: 1fr 2fr;
  gap: 20px;
}

.profile-card-left {
  background: var(--bg-card);
  border-radius: var(--radius-lg);
  padding: 24px;
  text-align: center;
  box-shadow: var(--shadow-sm);
  border: 1px solid var(--border-light);
}

.profile-username-menu > summary {
  list-style: none;
  cursor: pointer;
}

.profile-username-menu > summary::-webkit-details-marker {
  display: none;
}

.profile-avatar-large {
  font-size: 3.5rem;
  margin-bottom: 8px;
}

.badges-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(110px, 1fr));
  gap: 12px;
  margin-top: 12px;
}

.badge-item {
  background: var(--bg-main);
  border-radius: var(--radius-md);
  padding: 12px 8px;
  text-align: center;
  border: 1px solid var(--border-light);
  opacity: 0.4;
  filter: grayscale(1);
}

.badge-item.unlocked {
  opacity: 1;
  filter: grayscale(0);
  border-color: var(--accent-gold);
  background: #fffdf5;
}

.badge-icon-lg {
  font-size: 1.8rem;
  margin-bottom: 4px;
}

/* Footer */
.footer {
  background: var(--bg-card);
  border-top: 1px solid var(--border-light);
  padding: 24px 0;
  text-align: center;
  color: var(--text-secondary);
  font-size: 0.85rem;
  margin-top: auto;
}

/* ==========================================================================
   MEDIA QUERIES FOR MOBILE RESPONSIVENESS (< 768px)
   ========================================================================== */
@media (max-width: 768px) {
  #tab-flashcard.flashcard-centered.active {
    display: flex;
    flex-direction: column;
    justify-content: center;
    min-height: calc(100dvh - 150px);
  }

  #tab-kuis.quiz-menu-centered.active {
    min-height: calc(100dvh - 150px);
  }

  /* Hide Desktop Nav links, Show Mobile Bottom Nav */
  .nav-links {
    display: none;
  }

  #tab-kana-grid .filter-bar-group {
    width: 100%;
    align-items: stretch !important;
  }

  #tab-kana-grid .category-filter-bar {
    justify-content: flex-start !important;
  }
  
  .mobile-bottom-nav {
    display: block;
  }

  .user-nav-actions #mute-toggle-btn {
    display: none; /* Keep header clean on mobile */
  }

  /* Grid Layouts */
  .hero-card {
    grid-template-columns: 1fr;
    padding: 20px;
    gap: 20px;
  }

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

  .stroke-canvas-layout {
    grid-template-columns: 1fr;
  }

  /* 5-Column Kana Grid Matrix for Mobile screens */
  .kana-grid-container {
    grid-template-columns: repeat(5, 1fr);
    gap: 6px;
  }

  .kana-card {
    padding: 8px 4px;
    min-height: 90px;
  }

  .kana-char {
    font-size: 1.8rem;
  }

  .kana-romaji {
    font-size: 0.75rem;
  }

  .audio-btn-icon {
    display: none; /* Hide audio text on mobile card to keep clean 5-col grid */
  }

  .quiz-options-grid {
    grid-template-columns: 1fr;
  }

  .modal-content {
    padding: 20px 14px;
    max-height: 95vh;
  }

  .filter-bar {
    max-width: 100%;
  }

  .filter-btn {
    font-size: 0.8rem;
    padding: 6px 10px;
  }
}