static/css/style.css

/* ============================================
   ECHO TUTOR PRO — Premium Design System
   ============================================ */

/* --- CSS Custom Properties --- */
:root {
  --bg-primary: #0a0e1a;
  --bg-secondary: #111827;
  --bg-card: rgba(17, 24, 39, 0.6);
  --bg-glass: rgba(255, 255, 255, 0.04);
  --bg-glass-hover: rgba(255, 255, 255, 0.08);
  --border-glass: rgba(255, 255, 255, 0.08);
  --border-glow: rgba(99, 179, 237, 0.3);

  --accent: #63b3ed;
  --accent-bright: #90cdf4;
  --accent-dim: #2b6cb0;
  --accent-glow: rgba(99, 179, 237, 0.4);
  --accent-2: #9f7aea;
  --accent-2-glow: rgba(159, 122, 234, 0.3);

  --text-primary: #f7fafc;
  --text-secondary: #a0aec0;
  --text-muted: #718096;

  --success: #68d391;
  --warning: #f6ad55;
  --error: #fc8181;

  --user-msg: rgba(99, 179, 237, 0.12);
  --user-msg-border: rgba(99, 179, 237, 0.25);
  --ai-msg: rgba(159, 122, 234, 0.1);
  --ai-msg-border: rgba(159, 122, 234, 0.2);

  --radius-sm: 8px;
  --radius-md: 14px;
  --radius-lg: 20px;
  --radius-xl: 28px;
  --radius-full: 50%;

  --shadow-sm: 0 2px 8px rgba(0, 0, 0, 0.3);
  --shadow-md: 0 4px 20px rgba(0, 0, 0, 0.4);
  --shadow-lg: 0 8px 40px rgba(0, 0, 0, 0.5);
  --shadow-glow: 0 0 30px var(--accent-glow);

  --font-body: 'Inter', -apple-system, BlinkMacSystemFont, sans-serif;
  --font-mono: 'JetBrains Mono', monospace;

  --transition-fast: 0.15s ease;
  --transition-normal: 0.3s cubic-bezier(0.4, 0, 0.2, 1);
  --transition-slow: 0.5s cubic-bezier(0.4, 0, 0.2, 1);
}

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

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

body {
  font-family: var(--font-body);
  background: var(--bg-primary);
  color: var(--text-primary);
  min-height: 100vh;
  min-height: 100dvh;
  overflow-x: hidden;
  overflow-y: hidden;
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  -webkit-font-smoothing: antialiased;
}

/* --- Particle Background --- */
#particles-canvas {
  position: fixed;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  z-index: 0;
  pointer-events: none;
}

/* --- Toast Notification --- */
.toast {
  position: fixed;
  top: 20px;
  left: 50%;
  transform: translateX(-50%) translateY(-100px);
  background: rgba(17, 24, 39, 0.95);
  -webkit-backdrop-filter: blur(20px);
  backdrop-filter: blur(20px);
  border-left: 4px solid var(--accent-primary);
  border-radius: var(--radius-md);
  padding: 14px 24px;
  font-size: 0.9rem;
  font-weight: 500;
  color: #fff;
  box-shadow: 0 10px 30px rgba(0, 0, 0, 0.3);
  z-index: 9999;
  transition: transform 0.4s cubic-bezier(0.175, 0.885, 0.32, 1.275);
  pointer-events: none;
  display: flex;
  align-items: center;
  gap: 10px;
}
.toast.visible {
  transform: translateX(-50%) translateY(0);
}
.toast.error {
  border-left-color: var(--error);
}
.toast.success {
  border-left-color: var(--success);
}

/* --- RTL Support --- */
[dir="rtl"] {
  font-family: 'Cairo', 'Inter', sans-serif;
}
[dir="rtl"] .header-left {
  flex-direction: row-reverse;
}
[dir="rtl"] .header-left img {
  margin-right: 0 !important;
  margin-left: 12px !important;
}
[dir="rtl"] .header-right {
  flex-direction: row-reverse;
}
[dir="rtl"] .message.user {
  align-self: flex-start;
  border-radius: 18px 18px 4px 18px;
}
[dir="rtl"] .message.ai {
  align-self: flex-end;
  border-radius: 18px 18px 18px 4px;
}
[dir="rtl"] .input-wrapper {
  flex-direction: row-reverse;
}
[dir="rtl"] .chat-input {
  text-align: right;
}
[dir="rtl"] .modal-header {
  flex-direction: row-reverse;
}
[dir="rtl"] .modal-close {
  margin-left: 0;
  margin-right: auto;
}
[dir="rtl"] .nav-tab {
  flex-direction: column;
}
[dir="rtl"] .streak-display {
  margin-left: 10px;
  margin-right: 0;
}

/* ============================================
   ONBOARDING SCREEN
   ============================================ */
.onboarding-screen {
  position: fixed;
  inset: 0;
  z-index: 100;
  display: block;
  background: var(--bg-primary);
  animation: fadeIn 0.6s ease;
  overflow-y: auto;
  padding: 0;
}
.onboarding-screen.hidden {
  opacity: 0;
  pointer-events: none;
  transition: opacity 0.5s ease;
}

/* Make onboarding-content always centered and scrollable if needed */
.onboarding-content {
  position: absolute;
  top: 0;
  left: 50%;
  transform: translateX(-50%);
  width: 100%;
  max-width: 520px;
  min-height: 100vh;
  box-sizing: border-box;
  text-align: center;
  padding: 32px 12px 32px 12px;
  animation: slideUp 0.7s cubic-bezier(0.16, 1, 0.3, 1);
  overflow-y: auto;
}

/* Logo Orb */
.onboarding-logo {
  margin-bottom: 24px;
  display: flex;
  justify-content: center;
}
.logo-orb {
  width: 80px;
  height: 80px;
  position: relative;
  display: flex;
  align-items: center;
  justify-content: center;
}
.logo-core {
  width: 36px;
  height: 36px;
  background: radial-gradient(
    circle,
    var(--accent-bright) 0%,
    var(--accent) 50%,
    var(--accent-dim) 100%
  );
  border-radius: var(--radius-full);
  box-shadow:
    0 0 20px var(--accent-glow),
    0 0 60px rgba(99, 179, 237, 0.15);
  animation: corePulse 3s ease-in-out infinite;
}
.logo-ring {
  position: absolute;
  border-radius: var(--radius-full);
  border: 1.5px solid;
}
.logo-ring.ring-1 {
  width: 58px;
  height: 58px;
  border-color: rgba(99, 179, 237, 0.25);
  animation: ringRotate 8s linear infinite;
}
.logo-ring.ring-2 {
  width: 76px;
  height: 76px;
  border-color: rgba(159, 122, 234, 0.15);
  animation: ringRotate 12s linear infinite reverse;
}

.onboarding-title {
  font-size: 2.2rem;
  font-weight: 700;
  letter-spacing: 3px;
  margin-bottom: 6px;
}
.accent {
  color: var(--accent);
}

.onboarding-subtitle {
  font-size: 0.95rem;
  color: var(--text-muted);
  margin-bottom: 32px;
  font-weight: 300;
}

/* Selection Sections */
.selection-section {
  margin-bottom: 24px;
}
.selection-label {
  font-size: 0.8rem;
  text-transform: uppercase;
  letter-spacing: 2px;
  color: var(--text-muted);
  margin-bottom: 12px;
  font-weight: 500;
}

/* Level Cards */
.level-cards {
  display: flex;
  gap: 10px;
  justify-content: center;
}
.level-card {
  background: var(--bg-glass);
  -webkit-backdrop-filter: blur(10px);
  backdrop-filter: blur(10px);
  border: 1px solid var(--border-glass);
  border-radius: var(--radius-md);
  padding: 14px 16px;
  min-width: 130px;
  cursor: pointer;
  transition: all var(--transition-normal);
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 4px;
  color: var(--text-secondary);
}
.level-card:hover {
  background: var(--bg-glass-hover);
  border-color: var(--border-glow);
  transform: translateY(-2px);
}
.level-card.active {
  background: rgba(99, 179, 237, 0.1);
  border-color: var(--accent);
  color: var(--text-primary);
  box-shadow: var(--shadow-glow);
}
.level-icon {
  font-size: 1.5rem;
}
.level-name {
  font-size: 0.85rem;
  font-weight: 600;
}
.level-desc {
  font-size: 0.7rem;
  color: var(--text-muted);
}

/* Topic Grid */
.topic-grid {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 8px;
}
.topic-card {
  background: var(--bg-glass);
  -webkit-backdrop-filter: blur(10px);
  backdrop-filter: blur(10px);
  border: 1px solid var(--border-glass);
  border-radius: var(--radius-sm);
  padding: 12px 6px;
  cursor: pointer;
  transition: all var(--transition-normal);
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 4px;
  color: var(--text-secondary);
  font-size: 0.75rem;
}
.topic-card:hover {
  background: var(--bg-glass-hover);
  border-color: var(--border-glow);
  transform: translateY(-2px);
}
.topic-card.active {
  background: rgba(159, 122, 234, 0.1);
  border-color: var(--accent-2);
  color: var(--text-primary);
  box-shadow: 0 0 20px var(--accent-2-glow);
}
.topic-icon {
  font-size: 1.3rem;
}
.topic-name {
  font-weight: 500;
}

/* Start Button */
.start-btn {
  margin-top: 28px;
  padding: 14px 44px;
  background: linear-gradient(135deg, var(--accent) 0%, var(--accent-2) 100%);
  border: none;
  border-radius: var(--radius-xl);
  color: white;
  font-size: 1rem;
  font-weight: 600;
  cursor: pointer;
  display: inline-flex;
  align-items: center;
  gap: 10px;
  transition: all var(--transition-normal);
  box-shadow: 0 4px 20px var(--accent-glow);
  letter-spacing: 0.5px;
}
.start-btn:hover {
  transform: translateY(-2px) scale(1.02);
  box-shadow: 0 8px 30px var(--accent-glow);
}
.start-btn:active {
  transform: scale(0.98);
}

/* ============================================
   MAIN APP CONTAINER
   ============================================ */
.app-container {
  position: relative;
  z-index: 1;
  width: 100%;
  max-width: 480px;
  height: 100vh;
  height: 100dvh;
  display: flex;
  flex-direction: column;
  padding: 0 16px;
  animation: fadeIn 0.5s ease;
  /* Prevent content being hidden under keyboard on iOS */
  padding-bottom: env(safe-area-inset-bottom, 0px);
}
.app-container.hidden {
  display: none;
}

/* --- Header --- */
.app-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 14px 0 10px;
  flex-shrink: 0;
}
.header-left {
  display: flex;
  align-items: center;
  gap: 10px;
}
.header-orb {
  width: 32px;
  height: 32px;
  border-radius: var(--radius-full);
  background: rgba(99, 179, 237, 0.1);
  border: 1.5px solid rgba(99, 179, 237, 0.3);
  display: flex;
  align-items: center;
  justify-content: center;
}
.header-orb-core {
  width: 14px;
  height: 14px;
  background: var(--accent);
  border-radius: var(--radius-full);
  box-shadow: 0 0 10px var(--accent-glow);
  animation: corePulse 3s ease-in-out infinite;
}
.header-title {
  font-size: 1rem;
  font-weight: 700;
  letter-spacing: 2px;
}
.header-status {
  font-size: 0.65rem;
  color: var(--text-muted);
  text-transform: uppercase;
  letter-spacing: 1px;
}
.header-right {
  display: flex;
  align-items: center;
  gap: 8px;
}
.session-stats {
  display: flex;
  gap: 10px;
}
.stat {
  font-size: 0.72rem;
  color: var(--text-muted);
  font-family: var(--font-mono);
}
.icon-btn {
  width: 36px;
  height: 36px;
  border-radius: var(--radius-full);
  background: var(--bg-glass);
  border: 1px solid var(--border-glass);
  color: var(--text-muted);
  cursor: pointer;
  display: flex;
  align-items: center;
  justify-content: center;
  transition: all var(--transition-fast);
}
.icon-btn:hover {
  background: var(--bg-glass-hover);
  border-color: var(--border-glow);
  color: var(--text-primary);
}

/* --- Avatar Section --- */
.avatar-section {
  display: flex;
  flex-direction: column;
  align-items: center;
  padding: 10px 0 8px;
  flex-shrink: 0;
}

.avatar-container {
  position: relative;
  width: 140px;
  height: 140px;
  display: flex;
  align-items: center;
  justify-content: center;
}

/* Avatar Glow */
.avatar-glow {
  position: absolute;
  width: 120px;
  height: 120px;
  border-radius: var(--radius-full);
  background: radial-gradient(circle, var(--accent-glow) 0%, transparent 70%);
  filter: blur(20px);
  opacity: 0.4;
  transition:
    opacity var(--transition-normal),
    background var(--transition-normal);
  animation: glowPulse 4s ease-in-out infinite;
}

/* Avatar Rings */
.avatar-ring {
  position: absolute;
  border-radius: var(--radius-full);
  border: 1.5px solid;
  transition: all var(--transition-normal);
}
.ring-outer {
  width: 130px;
  height: 130px;
  border-color: rgba(99, 179, 237, 0.12);
  animation: ringRotate 10s linear infinite;
}
.ring-inner {
  width: 110px;
  height: 110px;
  border-color: rgba(159, 122, 234, 0.12);
  animation: ringRotate 7s linear infinite reverse;
}

/* Avatar Orb */
.avatar-orb {
  width: 88px;
  height: 88px;
  border-radius: var(--radius-full);
  background: linear-gradient(135deg, #1a365d 0%, #2b6cb0 50%, #1a365d 100%);
  border: 2px solid rgba(99, 179, 237, 0.3);
  display: flex;
  align-items: center;
  justify-content: center;
  position: relative;
  z-index: 2;
  transition: all var(--transition-normal);
  animation:
    float 5s ease-in-out infinite,
    breathe 4s ease-in-out infinite;
  box-shadow:
    inset 0 -4px 12px rgba(0, 0, 0, 0.3),
    0 0 20px var(--accent-glow);
}

/* Breathing animation */
.orb-breath {
  position: absolute;
  inset: -4px;
  border-radius: var(--radius-full);
  background: radial-gradient(
    circle,
    rgba(99, 179, 237, 0.1) 0%,
    transparent 70%
  );
  animation: breatheGlow 4s ease-in-out infinite;
  pointer-events: none;
}

/* Avatar mini particles */
.avatar-particles {
  position: absolute;
  inset: -20px;
  pointer-events: none;
  z-index: 1;
}

/* Orb Face */
.orb-face {
  width: 60px;
  height: 60px;
  position: relative;
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
}

/* Eyebrows */
.orb-brows {
  display: flex;
  gap: 18px;
  margin-bottom: 2px;
  position: relative;
  z-index: 5;
}
.orb-brow {
  width: 12px;
  height: 3px;
  background: var(--accent-bright);
  border-radius: 3px;
  transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
  opacity: 0.8;
}
.orb-brow.left {
  transform: rotate(-8deg);
}
.orb-brow.right {
  transform: rotate(8deg);
}

/* Eyes */
.orb-eyes {
  display: flex;
  gap: 14px;
  margin-bottom: 6px;
}

.orb-eye {
  width: 14px;
  height: 14px;
  background: var(--accent-bright);
  border-radius: var(--radius-full);
  position: relative;
  transition: all 0.2s ease;
  box-shadow: 0 0 8px var(--accent-glow);
  overflow: hidden;
}

.orb-pupil {
  width: 5px;
  height: 5px;
  background: white;
  border-radius: var(--radius-full);
  position: absolute;
  top: 4px;
  left: 4px;
  transition: all 0.1s ease;
  z-index: 2;
}

.orb-eyelid {
  position: absolute;
  top: -100%;
  left: 0;
  width: 100%;
  height: 100%;
  background: #1a365d;
  border-radius: var(--radius-full);
  transition: top 0.08s ease;
  z-index: 3;
}

.orb-eye-shine {
  position: absolute;
  top: 2px;
  right: 2px;
  width: 4px;
  height: 4px;
  background: rgba(255, 255, 255, 0.7);
  border-radius: var(--radius-full);
  z-index: 4;
  pointer-events: none;
}

/* Cheeks */
.orb-cheeks {
  display: flex;
  justify-content: space-between;
  width: 50px;
  position: absolute;
  top: 32px;
}
.orb-cheek {
  width: 8px;
  height: 5px;
  border-radius: var(--radius-full);
  background: rgba(252, 129, 129, 0);
  transition: all 0.5s ease;
}

/* Mouth with lip-sync bars */
.orb-mouth-area {
  display: flex;
  justify-content: center;
}
.orb-mouth {
  display: flex;
  align-items: flex-end;
  justify-content: center;
  gap: 1px;
  height: 12px;
  width: 22px;
  transition: all var(--transition-fast);
}
.mouth-bar {
  width: 3px;
  height: 3px;
  background: var(--accent);
  border-radius: 1px;
  transition:
    height 0.08s ease,
    background 0.2s ease;
}

/* Emotion indicator */
.emotion-indicator {
  font-size: 1.1rem;
  height: 22px;
  margin-top: 4px;
  transition: all 0.4s ease;
  opacity: 0;
}
.emotion-indicator.visible {
  opacity: 1;
  animation: emotionPop 0.4s cubic-bezier(0.34, 1.56, 0.64, 1);
}

/* ─── AVATAR STATES ─── */

/* IDLE — Relaxed, slight smile */
.avatar-container .orb-brow.left {
  transform: rotate(-8deg);
}
.avatar-container .orb-brow.right {
  transform: rotate(8deg);
}
.avatar-container .mouth-bar {
  height: 3px;
  background: var(--accent);
}
.avatar-container .mouth-bar:nth-child(2),
.avatar-container .mouth-bar:nth-child(4) {
  height: 4px;
}
.avatar-container .mouth-bar:nth-child(3) {
  height: 5px;
}

/* LISTENING — Alert, wide eyes, raised brows */
.avatar-container.listening .avatar-glow {
  opacity: 0.6;
  background: radial-gradient(
    circle,
    rgba(72, 187, 120, 0.4) 0%,
    transparent 70%
  );
}
.avatar-container.listening .avatar-orb {
  border-color: rgba(72, 187, 120, 0.5);
  box-shadow:
    inset 0 -4px 12px rgba(0, 0, 0, 0.3),
    0 0 30px rgba(72, 187, 120, 0.3);
  animation:
    float 5s ease-in-out infinite,
    breathe 2s ease-in-out infinite;
}
.avatar-container.listening .orb-eye {
  background: var(--success);
  box-shadow: 0 0 12px rgba(72, 187, 120, 0.5);
  width: 16px;
  height: 16px;
}
.avatar-container.listening .orb-pupil {
  width: 6px;
  height: 6px;
  top: 5px;
  left: 5px;
}
.avatar-container.listening .orb-brow.left {
  transform: rotate(-2deg) translateY(-3px);
}
.avatar-container.listening .orb-brow.right {
  transform: rotate(2deg) translateY(-3px);
}
.avatar-container.listening .mouth-bar {
  height: 2px;
  background: var(--success);
}
.avatar-container.listening .mouth-bar:nth-child(3) {
  height: 3px;
}
.avatar-container.listening .ring-outer {
  border-color: rgba(72, 187, 120, 0.2);
  animation-duration: 3s;
}
.avatar-container.listening .ring-inner {
  border-color: rgba(72, 187, 120, 0.15);
  animation-duration: 2s;
}
.avatar-container.listening .orb-cheek {
  background: rgba(72, 187, 120, 0.15);
}

/* SPEAKING — Animated mouth bars, expressive brows */
.avatar-container.speaking .avatar-glow {
  opacity: 0.7;
  background: radial-gradient(circle, var(--accent-2-glow) 0%, transparent 70%);
}
.avatar-container.speaking .avatar-orb {
  border-color: rgba(159, 122, 234, 0.5);
  box-shadow:
    inset 0 -4px 12px rgba(0, 0, 0, 0.3),
    0 0 30px var(--accent-2-glow);
}
.avatar-container.speaking .orb-eye {
  background: var(--accent-2);
  box-shadow: 0 0 12px var(--accent-2-glow);
  width: 13px;
  height: 13px;
}
.avatar-container.speaking .orb-brow.left {
  transform: rotate(-12deg) translateY(-2px);
}
.avatar-container.speaking .orb-brow.right {
  transform: rotate(12deg) translateY(-2px);
}
.avatar-container.speaking .orb-brow {
  background: var(--accent-2);
}
.avatar-container.speaking .mouth-bar {
  background: var(--accent-2);
}
.avatar-container.speaking .ring-outer {
  border-color: rgba(159, 122, 234, 0.2);
  animation-duration: 4s;
}
.avatar-container.speaking .orb-cheek {
  background: rgba(159, 122, 234, 0.1);
}

/* THINKING — Squinting, concentrated */
.avatar-container.thinking .avatar-glow {
  opacity: 0.5;
  animation: glowPulse 1.5s ease-in-out infinite;
}
.avatar-container.thinking .orb-eye {
  height: 6px;
  width: 14px;
  border-radius: 7px;
}
.avatar-container.thinking .orb-pupil {
  width: 4px;
  height: 3px;
  top: 2px;
}
.avatar-container.thinking .orb-brow.left {
  transform: rotate(-15deg) translateY(1px);
}
.avatar-container.thinking .orb-brow.right {
  transform: rotate(15deg) translateY(1px);
}
.avatar-container.thinking .mouth-bar {
  height: 2px;
}
.avatar-container.thinking .mouth-bar:nth-child(3) {
  height: 3px;
}
.avatar-container.thinking .ring-outer {
  animation-duration: 2s;
}
.avatar-container.thinking .ring-inner {
  animation-duration: 1.5s;
}

/* HAPPY — Smiling, blushing cheeks */
.avatar-container.happy .orb-eye {
  height: 8px;
  width: 14px;
  border-radius: 14px 14px 4px 4px;
}
.avatar-container.happy .orb-cheek {
  background: rgba(252, 129, 129, 0.35);
  width: 10px;
  height: 6px;
}
.avatar-container.happy .orb-brow.left {
  transform: rotate(-4deg) translateY(-4px);
}
.avatar-container.happy .orb-brow.right {
  transform: rotate(4deg) translateY(-4px);
}
.avatar-container.happy .mouth-bar {
  background: var(--success);
  height: 4px;
}
.avatar-container.happy .mouth-bar:nth-child(2),
.avatar-container.happy .mouth-bar:nth-child(4) {
  height: 6px;
}
.avatar-container.happy .mouth-bar:nth-child(3) {
  height: 8px;
}

/* Waveform Canvas */
.waveform-canvas {
  position: absolute;
  bottom: -8px;
  left: 50%;
  transform: translateX(-50%);
  z-index: 3;
  opacity: 0;
  transition: opacity var(--transition-normal);
}
.avatar-container.listening .waveform-canvas {
  opacity: 1;
}

/* State Label */
.state-label {
  font-size: 0.75rem;
  color: var(--text-muted);
  text-transform: uppercase;
  letter-spacing: 2px;
  margin-top: 8px;
  transition: color var(--transition-normal);
}

/* Avatar Character Selector */
.avatar-chars {
  display: flex;
  gap: 8px;
  justify-content: center;
  margin-top: 10px;
}
.char-btn {
  background: rgba(255,255,255,0.05);
  border: 2px solid transparent;
  border-radius: 50%;
  width: 36px;
  height: 36px;
  font-size: 18px;
  cursor: pointer;
  transition: all 0.2s ease;
  display: flex;
  align-items: center;
  justify-content: center;
}
.char-btn:hover {
  background: rgba(255,255,255,0.12);
  transform: scale(1.15);
}
.char-btn.active {
  border-color: var(--accent-primary);
  background: rgba(99,179,237,0.15);
  box-shadow: 0 0 12px rgba(99,179,237,0.3);
}

/* Avatar Character CSS Animations */
.avatar-orb.char-robot {
  background: linear-gradient(135deg, #606778, #2d3142) !important;
  border-radius: 12px !important;
  box-shadow: 0 0 30px rgba(100,200,255,0.4) !important;
}
.avatar-orb.char-robot::before {
  content: '';
  position: absolute;
  top: 10px;
  left: 50%;
  transform: translateX(-50%);
  width: 8px;
  height: 8px;
  background: #00e5ff;
  border-radius: 50%;
  box-shadow: 0 0 8px #00e5ff;
  animation: robotBlink 2s infinite;
}
@keyframes robotBlink {
  0%, 90%, 100% { opacity: 1; }
  95% { opacity: 0; }
}

.avatar-orb.char-owl {
  background: linear-gradient(135deg, #6b4c23, #3d2b0c) !important;
  border-radius: 40% 40% 50% 50% !important;
}
.avatar-orb.char-owl::after {
  content: '🦉';
  position: absolute;
  font-size: 40px;
  top: 50%;
  left: 50%;
  transform: translate(-50%, -50%);
  animation: owlBob 2s ease-in-out infinite;
}
@keyframes owlBob {
  0%, 100% { transform: translate(-50%, -50%) rotate(-5deg); }
  50% { transform: translate(-50%, -52%) rotate(5deg); }
}

.avatar-orb.char-star {
  background: linear-gradient(135deg, #f6d365, #fda085) !important;
  clip-path: polygon(50% 0%, 61% 35%, 98% 35%, 68% 57%, 79% 91%, 50% 70%, 21% 91%, 32% 57%, 2% 35%, 39% 35%) !important;
  border-radius: 0 !important;
  animation: starSpin 4s linear infinite !important;
}
@keyframes starSpin {
  0% { transform: rotate(0deg) scale(1); }
  50% { transform: rotate(180deg) scale(1.05); }
  100% { transform: rotate(360deg) scale(1); }
}

/* Animated avatar speaking lips */
.avatar-orb.speaking .orb-mouth {
  animation: mouthTalk 0.3s steps(1) infinite;
}
@keyframes mouthTalk {
  0%, 100% { border-radius: 50% 50% 60% 60%; height: 18px; }
  50% { border-radius: 40% 40% 50% 50%; height: 8px; }
}
  padding: 16px;
  margin-bottom: 10px;
  overflow: hidden;
  display: flex;
  flex-direction: column;
  box-shadow: var(--shadow-md);
  min-height: 0;
}

.messages-container {
  flex: 1;
  overflow-y: auto;
  display: flex;
  flex-direction: column;
  gap: 8px;
  padding-right: 6px;
  scroll-behavior: smooth;
}

/* Custom Scrollbar */
.messages-container::-webkit-scrollbar {
  width: 4px;
}
.messages-container::-webkit-scrollbar-track {
  background: transparent;
}
.messages-container::-webkit-scrollbar-thumb {
  background: rgba(99, 179, 237, 0.2);
  border-radius: 2px;
}
.messages-container::-webkit-scrollbar-thumb:hover {
  background: rgba(99, 179, 237, 0.4);
}

/* Message Bubbles */
.message {
  padding: 10px 16px;
  border-radius: var(--radius-md);
  max-width: 85%;
  word-break: break-word;
  font-size: 0.9rem;
  line-height: 1.55;
  animation: msgSlideIn 0.35s cubic-bezier(0.16, 1, 0.3, 1);
  position: relative;
}

.message.user {
  background: var(--user-msg);
  border: 1px solid var(--user-msg-border);
  align-self: flex-start;
  color: var(--text-primary);
}

.message.ai {
  background: var(--ai-msg);
  border: 1px solid var(--ai-msg-border);
  align-self: flex-end;
  color: var(--text-primary);
}

.message.ai-error {
  background: rgba(252, 129, 129, 0.1);
  border: 1px solid rgba(252, 129, 129, 0.25);
  align-self: flex-end;
  color: var(--error);
}

/* Streaming message cursor */
.message.ai.streaming::after {
  content: '▋';
  animation: blink 0.8s infinite;
  color: var(--accent-2);
  margin-left: 2px;
}

/* Inline corrections/suggestions styling */
.message strong {
  color: var(--accent-bright);
  font-weight: 600;
}
.message em {
  color: var(--accent-2);
  font-style: italic;
}

/* Typing Indicator */
.typing-indicator {
  padding: 14px 18px;
  display: flex;
  align-items: center;
  gap: 4px;
}
.typing-indicator span {
  display: inline-block;
  width: 7px;
  height: 7px;
  background: var(--accent-2);
  border-radius: var(--radius-full);
  animation: typingBounce 1.4s infinite;
  opacity: 0.7;
}
.typing-indicator span:nth-child(2) {
  animation-delay: 0.15s;
}
.typing-indicator span:nth-child(3) {
  animation-delay: 0.3s;
}

/* --- Controls Bar --- */
.controls-bar {
  display: flex;
  align-items: center;
  gap: 8px;
  padding: 10px 0 20px;
  flex-shrink: 0;
  /* Always visible above keyboard */
  position: relative;
  z-index: 10;
  padding-bottom: max(20px, env(safe-area-inset-bottom, 20px));
}

.ctrl-btn {
  width: 46px;
  height: 46px;
  border-radius: var(--radius-full);
  border: 1.5px solid var(--border-glass);
  background: var(--bg-glass);
  -webkit-backdrop-filter: blur(10px);
  backdrop-filter: blur(10px);
  color: var(--text-secondary);
  cursor: pointer;
  display: flex;
  align-items: center;
  justify-content: center;
  transition: all var(--transition-fast);
  flex-shrink: 0;
  position: relative;
  outline: none;
}
.ctrl-btn:hover {
  background: var(--bg-glass-hover);
  border-color: var(--border-glow);
  color: var(--text-primary);
  transform: scale(1.05);
}
.ctrl-btn:active {
  transform: scale(0.95);
}

.stt-btn {
  min-width: 52px;
  padding: 0 6px;
  font-size: 0.62rem;
  font-weight: 700;
  letter-spacing: 0.5px;
}

/* Mic Button */
.mic-btn.active {
  background: rgba(72, 187, 120, 0.15);
  border-color: var(--success);
  color: var(--success);
}
.mic-pulse {
  position: absolute;
  width: 100%;
  height: 100%;
  border-radius: var(--radius-full);
  border: 2px solid var(--success);
  opacity: 0;
  pointer-events: none;
}
.mic-btn.active .mic-pulse {
  animation: micPulse 1.5s ease-out infinite;
}

/* Send Button */
.send-btn {
  background: linear-gradient(135deg, var(--accent) 0%, var(--accent-2) 100%);
  border: none;
  color: white;
}
.send-btn:hover {
  box-shadow: 0 0 20px var(--accent-glow);
  transform: scale(1.08);
}

/* End Button */
.end-btn:hover {
  border-color: var(--error);
  color: var(--error);
  background: rgba(252, 129, 129, 0.1);
}

/* Mute Button */
.mute-btn.muted {
  border-color: var(--warning);
  color: var(--warning);
}

/* Input */
.input-wrapper {
  flex: 1;
}
.chat-input {
  width: 100%;
  background: var(--bg-glass);
  -webkit-backdrop-filter: blur(10px);
  backdrop-filter: blur(10px);
  border: 1.5px solid var(--border-glass);
  border-radius: var(--radius-xl);
  padding: 12px 18px;
  color: var(--text-primary);
  font-size: 0.9rem;
  font-family: var(--font-body);
  outline: none;
  transition: all var(--transition-fast);
}
.chat-input::placeholder {
  color: var(--text-muted);
}
.chat-input:focus {
  border-color: var(--border-glow);
  box-shadow: 0 0 15px rgba(99, 179, 237, 0.1);
  background: var(--bg-glass-hover);
}

/* ============================================
   KEYFRAME ANIMATIONS
   ============================================ */
@keyframes fadeIn {
  from {
    opacity: 0;
  }
  to {
    opacity: 1;
  }
}

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

@keyframes float {
  0%,
  100% {
    transform: translateY(0);
  }
  50% {
    transform: translateY(-8px);
  }
}

@keyframes corePulse {
  0%,
  100% {
    transform: scale(1);
    opacity: 1;
  }
  50% {
    transform: scale(1.1);
    opacity: 0.85;
  }
}

@keyframes glowPulse {
  0%,
  100% {
    opacity: 0.4;
    transform: scale(1);
  }
  50% {
    opacity: 0.6;
    transform: scale(1.05);
  }
}

@keyframes ringRotate {
  from {
    transform: rotate(0deg);
  }
  to {
    transform: rotate(360deg);
  }
}

@keyframes mouthSpeak {
  0% {
    height: 8px;
    width: 22px;
  }
  100% {
    height: 14px;
    width: 26px;
  }
}

@keyframes msgSlideIn {
  from {
    opacity: 0;
    transform: translateY(12px) scale(0.97);
  }
  to {
    opacity: 1;
    transform: translateY(0) scale(1);
  }
}

@keyframes typingBounce {
  0%,
  60%,
  100% {
    transform: translateY(0);
  }
  30% {
    transform: translateY(-6px);
  }
}

@keyframes blink {
  0%,
  100% {
    opacity: 1;
  }
  50% {
    opacity: 0;
  }
}

@keyframes micPulse {
  0% {
    transform: scale(1);
    opacity: 0.6;
  }
  100% {
    transform: scale(1.6);
    opacity: 0;
  }
}

@keyframes breathe {
  0%,
  100% {
    transform: translateY(0) scale(1);
  }
  50% {
    transform: translateY(-4px) scale(1.02);
  }
}

@keyframes breatheGlow {
  0%,
  100% {
    opacity: 0.15;
    transform: scale(1);
  }
  50% {
    opacity: 0.35;
    transform: scale(1.08);
  }
}

@keyframes emotionPop {
  0% {
    transform: scale(0) translateY(5px);
    opacity: 0;
  }
  70% {
    transform: scale(1.2) translateY(-2px);
    opacity: 1;
  }
  100% {
    transform: scale(1) translateY(0);
    opacity: 1;
  }
}

/* ============================================
   RESPONSIVE
   ============================================ */
@media (max-width: 520px) {
  /* ── BODY ── */
  body {
    overflow-y: auto; /* allow onboarding to scroll */
  }
  body.in-chat {
    overflow-y: hidden; /* lock scroll in chat */
  }

  /* ── APP CONTAINER ── */
  .app-container {
    padding: 0 8px;
    /* dvh shrinks when keyboard opens; svh as older-browser fallback */
    height: 100svh;
    height: 100dvh;
    max-width: 100%;
    min-height: 0;
    display: flex;
    flex-direction: column;
    padding-bottom: 0;
    overscroll-behavior: none;
  }

  /* ── HEADER ── */
  .app-header {
    padding: 8px 0 6px;
    flex-shrink: 0;
    gap: 4px;
  }
  .header-left {
    gap: 6px;
    flex-shrink: 0;
  }
  .header-left img {
    width: 30px !important;
    height: 30px !important;
    margin-right: 6px !important;
  }
  .header-title {
    font-size: 0.8rem;
    letter-spacing: 1px;
  }
  .header-status {
    font-size: 0.55rem;
  }
  .header-right {
    gap: 4px;
    overflow: hidden;
    flex-shrink: 1;
  }
  /* Hide less critical header items on mobile to prevent overflow */
  .session-stats {
    display: none;
  }
  .xp-display {
    display: none;
  }
  .streak-display {
    font-size: 0.75rem;
    flex-shrink: 0;
  }
  .icon-btn {
    width: 32px;
    height: 32px;
    flex-shrink: 0;
    touch-action: manipulation;
    -webkit-tap-highlight-color: transparent;
  }

  /* ── AVATAR ── */
  .avatar-section {
    padding: 4px 0 2px;
    flex-shrink: 0;
  }
  .avatar-container {
    width: 90px;
    height: 90px;
  }
  .avatar-glow {
    width: 78px;
    height: 78px;
  }
  .ring-outer {
    width: 86px;
    height: 86px;
  }
  .ring-inner {
    width: 74px;
    height: 74px;
  }
  .avatar-orb {
    width: 60px;
    height: 60px;
  }
  .state-label {
    font-size: 0.6rem;
    margin-top: 4px;
    letter-spacing: 1px;
  }
  .emotion-indicator {
    height: 16px;
    font-size: 0.85rem;
  }

  /* ── CHAT PANEL ── */
  .chat-panel {
    flex: 1;
    min-height: 0;
    overflow: hidden;
    padding: 10px;
    margin-bottom: 0;
  }
  .messages-container {
    overflow-y: scroll;
    -webkit-overflow-scrolling: touch;
    overscroll-behavior: contain;
  }

  /* ── CONTROLS BAR ── */
  .controls-bar {
    display: flex;
    align-items: center;
    gap: 5px;
    padding: 8px 0 max(14px, env(safe-area-inset-bottom, 14px));
    flex-shrink: 0;
    position: sticky;
    bottom: 0;
    background: var(--bg-primary);
    border-top: 1px solid var(--border-glass);
    z-index: 20;
    /* GPU layer — prevents Android Chrome burying bar behind keyboard */
    transform: translateZ(0);
    -webkit-transform: translateZ(0);
    will-change: transform;
  }

  /* All control buttons: 44px touch target (Apple/Google HIG minimum) */
  .ctrl-btn {
    width: 44px;
    height: 44px;
    flex-shrink: 0;
    touch-action: manipulation;
    -webkit-tap-highlight-color: transparent;
    /* Make embedded SVGs not steal pointer events */
    pointer-events: auto;
  }
  .ctrl-btn svg,
  .ctrl-btn span {
    pointer-events: none;
  }

  .send-btn {
    width: 48px;
    height: 44px;
    flex-shrink: 0;
  }

  /* Shrink the AUTO / STT label button to save space */
  .stt-btn {
    width: 36px;
    height: 44px;
    font-size: 0.55rem;
    padding: 0 2px;
    min-width: 36px;
  }

  .chat-input {
    font-size: 16px; /* blocks iOS auto-zoom (needs ≥16px) */
    padding: 10px 12px;
    -webkit-tap-highlight-color: transparent;
    min-width: 0; /* allow flex shrink */
  }

  /* ── ONBOARDING ── */
  .onboarding-title {
    font-size: 1.8rem;
  }
  .level-cards {
    flex-direction: column;
    align-items: center;
  }
  .level-card {
    min-width: 90%;
  }
  .topic-grid {
    grid-template-columns: repeat(2, 1fr);
  }
  .scenario-grid {
    grid-template-columns: repeat(2, 1fr);
  }

  /* ── SIDE PANEL ── */
  .side-panel {
    width: 100%;
    right: -100%;
  }

  /* ── MODALS ── */
  .modal-card {
    width: 95vw;
    max-height: 90vh;
    overflow-y: auto;
    -webkit-overflow-scrolling: touch;
  }
}

@media (max-height: 720px) and (max-width: 900px) {
  .app-header {
    padding: 10px 0 8px;
  }
  .avatar-section {
    padding: 6px 0 4px;
  }
  .avatar-container {
    width: 112px;
    height: 112px;
  }
  .avatar-glow {
    width: 96px;
    height: 96px;
  }
  .ring-outer {
    width: 104px;
    height: 104px;
  }
  .ring-inner {
    width: 88px;
    height: 88px;
  }
  .avatar-orb {
    width: 68px;
    height: 68px;
  }
  .state-label {
    margin-top: 6px;
    font-size: 0.7rem;
  }

  .chat-panel {
    padding: 12px;
    margin-bottom: 8px;
  }
  .controls-bar {
    padding: 8px 0 14px;
  }
  .ctrl-btn {
    width: 42px;
    height: 42px;
  }
  .chat-input {
    padding: 10px 16px;
  }
}

@media (min-width: 1024px) {
  .app-container {
    max-width: 720px;
    padding: 0 24px;
  }
  .onboarding-content {
    max-width: 760px;
  }
  .topic-grid,
  .scenario-grid {
    grid-template-columns: repeat(4, minmax(0, 1fr));
  }
}

@media (min-width: 521px) and (max-width: 768px) {
  .topic-grid {
    grid-template-columns: repeat(4, 1fr);
  }
}

/* ============================================
   PRONUNCIATION BAR
   ============================================ */
.pronunciation-bar {
  display: flex;
  flex-direction: column;
  gap: 6px;
  padding: 10px 16px;
  background: var(--bg-glass);
  -webkit-backdrop-filter: blur(10px);
  backdrop-filter: blur(10px);
  border: 1px solid var(--border-glass);
  border-radius: var(--radius-md);
  margin-bottom: 6px;
  animation: slideUp 0.4s ease;
}
.pronun-score-visual {
  display: flex;
  align-items: center;
  justify-content: space-between;
}
.pronun-stars {
  display: flex;
  gap: 2px;
}
.pronun-star {
  font-size: 0.85rem;
  transition: all 0.2s ease;
}
.pronun-star.filled {
  filter: none;
}
.pronun-star.empty {
  opacity: 0.25;
  filter: grayscale(1);
}
.pronun-score-num {
  font-family: var(--font-mono);
  font-size: 0.85rem;
  font-weight: 600;
  color: var(--accent-bright);
}
.pronun-bar-track {
  height: 6px;
  background: rgba(255, 255, 255, 0.06);
  border-radius: 3px;
  overflow: hidden;
}
.pronun-bar-fill {
  height: 100%;
  background: linear-gradient(
    90deg,
    var(--error) 0%,
    #f6ad55 30%,
    var(--success) 70%,
    #38b2ac 100%
  );
  border-radius: 3px;
  transition: width 0.6s cubic-bezier(0.4, 0, 0.2, 1);
}
.pronun-label {
  font-size: 0.72rem;
  color: var(--text-muted);
  text-align: center;
}

/* ============================================
   SESSION SUMMARY MODAL
   ============================================ */
.modal-overlay {
  position: fixed;
  inset: 0;
  background: rgba(0, 0, 0, 0.65);
  -webkit-backdrop-filter: blur(8px);
  backdrop-filter: blur(8px);
  z-index: 10000;
  display: flex;
  align-items: center;
  justify-content: center;
  animation: fadeIn 0.3s ease;
  padding: 20px;
}
.modal-card {
  background: var(--bg-card);
  border: 1px solid var(--border-glass);
  border-radius: var(--radius-xl);
  padding: 28px;
  max-width: 440px;
  width: 100%;
  animation: slideUp 0.4s cubic-bezier(0.34, 1.56, 0.64, 1);
  box-shadow: 0 20px 60px rgba(0, 0, 0, 0.4);
}
.modal-header {
  display: flex;
  justify-content: space-between;
  align-items: center;
  margin-bottom: 20px;
}
.modal-header h2 {
  font-size: 1.2rem;
  font-weight: 600;
  color: var(--text-primary);
  font-family: var(--font-heading);
}
.modal-close {
  background: none;
  border: none;
  color: var(--text-muted);
  font-size: 1.5rem;
  cursor: pointer;
  line-height: 1;
  transition: color 0.2s;
}
.modal-close:hover {
  color: var(--text-primary);
}
.summary-stats {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(100px, 1fr));
  gap: 12px;
  margin-bottom: 22px;
}
.summary-stat {
  background: var(--bg-glass);
  border: 1px solid var(--border-glass);
  border-radius: var(--radius-md);
  padding: 14px 10px;
  text-align: center;
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 4px;
}
.summary-stat-icon {
  font-size: 1.3rem;
}
.summary-stat-val {
  font-size: 1.4rem;
  font-weight: 700;
  color: var(--accent-bright);
  font-family: var(--font-mono);
}
.summary-stat-label {
  font-size: 0.65rem;
  color: var(--text-muted);
  text-transform: uppercase;
  letter-spacing: 0.5px;
}
.progress-section {
  margin-bottom: 20px;
}
.progress-section h3 {
  font-size: 0.85rem;
  color: var(--text-secondary);
  margin-bottom: 10px;
  font-weight: 500;
}
.progress-bars {
  display: flex;
  gap: 6px;
  align-items: flex-end;
  height: 60px;
}
.progress-bar-day {
  flex: 1;
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 4px;
}
.progress-bar-fill {
  width: 100%;
  min-height: 4px;
  background: linear-gradient(to top, var(--accent), var(--accent-2));
  border-radius: 3px 3px 0 0;
  transition: height 0.5s ease;
}
.progress-bar-label {
  font-size: 0.55rem;
  color: var(--text-muted);
  text-transform: uppercase;
}
.btn-primary {
  width: 100%;
  padding: 12px;
  background: linear-gradient(135deg, var(--accent) 0%, var(--accent-2) 100%);
  border: none;
  border-radius: var(--radius-md);
  color: white;
  font-weight: 600;
  font-size: 0.9rem;
  cursor: pointer;
  transition: all var(--transition-fast);
  font-family: var(--font-body);
}
.btn-primary:hover {
  transform: translateY(-1px);
  box-shadow: 0 8px 25px var(--accent-glow);
}

/* ============================================
   SIDE PANEL (Grammar + Vocab)
   ============================================ */
.side-panel {
  position: fixed;
  top: 0;
  right: -360px;
  width: 360px;
  height: 100vh;
  height: 100dvh;
  background: var(--bg-card);
  border-left: 1px solid var(--border-glass);
  z-index: 9000;
  display: flex;
  flex-direction: column;
  transition: right 0.35s cubic-bezier(0.4, 0, 0.2, 1);
  box-shadow: -10px 0 40px rgba(0, 0, 0, 0.3);
}
.side-panel.open {
  right: 0;
}
.panel-header {
  display: flex;
  justify-content: space-between;
  align-items: center;
  padding: 16px;
  border-bottom: 1px solid var(--border-glass);
}
.panel-tabs {
  display: flex;
  gap: 4px;
  flex-wrap: wrap;
}
.panel-tab {
  padding: 6px 14px;
  background: transparent;
  border: 1px solid var(--border-glass);
  border-radius: var(--radius-sm);
  color: var(--text-muted);
  font-size: 0.78rem;
  cursor: pointer;
  transition: all 0.2s;
  font-family: var(--font-body);
}
.panel-tab.active {
  background: var(--bg-glass-hover);
  color: var(--accent-bright);
  border-color: var(--accent);
}
.panel-close {
  background: none;
  border: none;
  color: var(--text-muted);
  font-size: 1.4rem;
  cursor: pointer;
  line-height: 1;
}
.panel-close:hover {
  color: var(--text-primary);
}
.panel-body {
  flex: 1;
  overflow-y: auto;
  padding: 14px;
}
.panel-empty {
  text-align: center;
  padding: 30px 10px;
  color: var(--text-muted);
  font-size: 0.82rem;
}

/* Corrections */
.correction-card {
  background: var(--bg-glass);
  border: 1px solid var(--border-glass);
  border-radius: var(--radius-sm);
  padding: 10px 12px;
  margin-bottom: 8px;
  animation: msgSlideIn 0.3s ease;
}
.correction-wrong {
  color: var(--error);
  text-decoration: line-through;
  font-size: 0.82rem;
  opacity: 0.7;
}
.correction-right {
  color: var(--success);
  font-weight: 500;
  font-size: 0.85rem;
}
.correction-arrow {
  color: var(--text-muted);
  margin: 0 6px;
  font-size: 0.75rem;
}

/* Vocab Controls */
.vocab-controls {
  display: flex;
  gap: 4px;
  margin-bottom: 12px;
}
.vocab-mode-btn {
  flex: 1;
  padding: 6px;
  background: transparent;
  border: 1px solid var(--border-glass);
  border-radius: var(--radius-sm);
  color: var(--text-muted);
  font-size: 0.72rem;
  cursor: pointer;
  transition: all 0.2s;
  font-family: var(--font-body);
}
.vocab-mode-btn.active {
  background: var(--bg-glass-hover);
  color: var(--accent-bright);
  border-color: var(--accent);
}

/* Vocab Word Item */
.vocab-item {
  display: flex;
  justify-content: space-between;
  align-items: center;
  padding: 8px 10px;
  background: var(--bg-glass);
  border: 1px solid var(--border-glass);
  border-radius: var(--radius-sm);
  margin-bottom: 6px;
  animation: msgSlideIn 0.3s ease;
}
.vocab-word {
  font-weight: 600;
  color: var(--accent-bright);
  font-size: 0.85rem;
}
.vocab-context {
  font-size: 0.72rem;
  color: var(--text-muted);
  margin-top: 2px;
}
.vocab-remove {
  background: none;
  border: none;
  color: var(--text-muted);
  cursor: pointer;
  font-size: 0.8rem;
  opacity: 0.5;
}
.vocab-remove:hover {
  opacity: 1;
  color: var(--error);
}

/* 3D Flashcard */
.flashcard-view {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 14px;
  padding: 10px 0;
}
.flashcard {
  width: 100%;
  max-width: 280px;
  height: 180px;
  perspective: 600px;
  cursor: pointer;
}
.flashcard-inner {
  width: 100%;
  height: 100%;
  position: relative;
  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;
  inset: 0;
  -webkit-backface-visibility: hidden;
  backface-visibility: hidden;
  display: flex;
  align-items: center;
  justify-content: center;
  padding: 20px;
  border-radius: var(--radius-md);
  border: 1px solid var(--border-glass);
  text-align: center;
}
.flashcard-front {
  background: linear-gradient(
    135deg,
    rgba(99, 179, 237, 0.15),
    rgba(159, 122, 234, 0.15)
  );
  font-size: 1.3rem;
  font-weight: 600;
  color: var(--accent-bright);
}
.flashcard-back {
  background: var(--bg-glass-hover);
  transform: rotateY(180deg);
  font-size: 0.9rem;
  color: var(--text-secondary);
}
.flashcard-nav {
  display: flex;
  align-items: center;
  gap: 16px;
}
.fc-btn {
  width: 36px;
  height: 36px;
  border-radius: var(--radius-full);
  border: 1px solid var(--border-glass);
  background: var(--bg-glass);
  color: var(--text-secondary);
  cursor: pointer;
  font-size: 1rem;
  transition: all 0.2s;
  font-family: var(--font-body);
}
.fc-btn:hover {
  background: var(--bg-glass-hover);
  border-color: var(--accent);
  color: var(--accent-bright);
}
.fc-counter {
  font-size: 0.78rem;
  color: var(--text-muted);
  font-family: var(--font-mono);
}

/* Quiz */
.quiz-view {
  padding: 10px 0;
}
.quiz-question {
  background: var(--bg-glass);
  border: 1px solid var(--border-glass);
  border-radius: var(--radius-md);
  padding: 20px;
  text-align: center;
  font-size: 0.95rem;
  color: var(--text-secondary);
  margin-bottom: 14px;
}
.quiz-options {
  display: flex;
  flex-direction: column;
  gap: 6px;
}
.quiz-option {
  padding: 10px 14px;
  background: var(--bg-glass);
  border: 1px solid var(--border-glass);
  border-radius: var(--radius-sm);
  color: var(--text-primary);
  font-size: 0.85rem;
  cursor: pointer;
  transition: all 0.2s;
  text-align: left;
  font-family: var(--font-body);
}
.quiz-option:hover {
  background: var(--bg-glass-hover);
  border-color: var(--accent);
}
.quiz-option.correct {
  background: rgba(72, 187, 120, 0.15);
  border-color: var(--success);
  color: var(--success);
}
.quiz-option.wrong {
  background: rgba(252, 129, 129, 0.15);
  border-color: var(--error);
  color: var(--error);
}
.quiz-result {
  text-align: center;
  padding: 10px;
  font-size: 0.9rem;
  font-weight: 500;
  margin-top: 10px;
}
.quiz-next {
  margin-top: 12px;
}

/* Voice Profiles */
.voice-profiles-list {
  display: flex;
  flex-wrap: wrap;
  gap: 6px;
  margin-bottom: 12px;
}
.voice-profile-chip {
  border: 1px solid var(--border-glass);
  background: var(--bg-glass);
  color: var(--text-secondary);
  border-radius: var(--radius-sm);
  padding: 6px 10px;
  font-size: 0.72rem;
  cursor: pointer;
}
.voice-profile-chip.active {
  border-color: var(--accent);
  color: var(--accent-bright);
  background: var(--bg-glass-hover);
}
.voice-editor {
  display: flex;
  flex-direction: column;
  gap: 8px;
}
.voice-input,
.voice-select {
  width: 100%;
  border: 1px solid var(--border-glass);
  background: var(--bg-glass);
  color: var(--text-primary);
  border-radius: var(--radius-sm);
  padding: 8px 10px;
  font-size: 0.8rem;
  font-family: var(--font-body);
}
.voice-label {
  font-size: 0.68rem;
  color: var(--text-muted);
  text-transform: uppercase;
  letter-spacing: 0.4px;
}
.voice-actions {
  display: flex;
  gap: 8px;
  margin-top: 6px;
}
.voice-actions .btn-primary,
.voice-actions .btn-secondary {
  width: auto;
  padding: 8px 12px;
  font-size: 0.78rem;
}

/* App Settings */
.settings-group {
  background: var(--bg-glass);
  border: 1px solid var(--border-glass);
  border-radius: var(--radius-md);
  padding: 10px;
  margin-bottom: 10px;
}
.settings-title {
  font-size: 0.74rem;
  color: var(--accent-bright);
  text-transform: uppercase;
  letter-spacing: 0.6px;
  margin-bottom: 8px;
}
.setting-item {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 10px;
  padding: 8px 6px;
  border-radius: var(--radius-sm);
}
.setting-item + .setting-item {
  border-top: 1px solid var(--border-glass);
}
.setting-copy {
  display: flex;
  flex-direction: column;
  gap: 2px;
}
.setting-name {
  font-size: 0.82rem;
  color: var(--text-primary);
  font-weight: 600;
}
.setting-desc {
  font-size: 0.72rem;
  color: var(--text-muted);
}
.setting-item input[type='checkbox'] {
  width: 18px;
  height: 18px;
  accent-color: var(--accent);
  cursor: pointer;
}

/* UI behavior modifiers */
body.ui-compact .message {
  padding: 8px 12px;
  font-size: 0.84rem;
  line-height: 1.45;
}
body.ui-compact .chat-panel {
  padding: 12px;
}
body.ui-compact .controls-bar {
  padding: 8px 0 14px;
}
body.ui-compact .ctrl-btn {
  width: 42px;
  height: 42px;
}

body.ui-reduced-motion * {
  animation-duration: 0.01ms !important;
  animation-iteration-count: 1 !important;
  transition-duration: 0.01ms !important;
}

body.no-particles #particles-canvas {
  display: none;
}

body.no-waveform .waveform-canvas {
  display: none;
}

/* Utility */
.hidden {
  display: none !important;
}

/* ============================================
   LIGHT THEME
   ============================================ */
[data-theme='light'] {
  --bg-primary: #f0f4f8;
  --bg-secondary: #ffffff;
  --bg-card: rgba(255, 255, 255, 0.85);
  --bg-glass: rgba(0, 0, 0, 0.03);
  --bg-glass-hover: rgba(0, 0, 0, 0.06);
  --border-glass: rgba(0, 0, 0, 0.1);
  --text-primary: #1a202c;
  --text-secondary: #2d3748;
  --text-muted: #718096;
  --text-hint: #a0aec0;
  --shadow-glow: 0 4px 20px rgba(99, 179, 237, 0.15);
  --accent-glow: rgba(99, 179, 237, 0.2);
  --accent-2-glow: rgba(159, 122, 234, 0.2);
}
[data-theme='light'] body {
  background: #f0f4f8;
}
[data-theme='light'] #particles-canvas {
  opacity: 0.15;
}
[data-theme='light'] .app-header {
  background: rgba(255, 255, 255, 0.7);
  border-bottom-color: rgba(0, 0, 0, 0.08);
}
[data-theme='light'] .message.user {
  background: linear-gradient(
    135deg,
    rgba(99, 179, 237, 0.2),
    rgba(99, 179, 237, 0.1)
  );
  border-color: rgba(99, 179, 237, 0.3);
}
[data-theme='light'] .message.ai {
  background: rgba(255, 255, 255, 0.7);
  border-color: rgba(0, 0, 0, 0.08);
}
[data-theme='light'] .controls-bar {
  background: rgba(255, 255, 255, 0.8);
  border-top-color: rgba(0, 0, 0, 0.08);
}
[data-theme='light'] .chat-input {
  background: rgba(0, 0, 0, 0.04);
  border-color: rgba(0, 0, 0, 0.1);
  color: #1a202c;
}
[data-theme='light'] .side-panel {
  background: rgba(255, 255, 255, 0.95);
  border-left-color: rgba(0, 0, 0, 0.1);
}
[data-theme='light'] .modal-card {
  background: #ffffff;
  border-color: rgba(0, 0, 0, 0.1);
}
[data-theme='light'] .onboarding-screen {
  background: #f0f4f8;
}
[data-theme='light'] .level-card,
[data-theme='light'] .topic-card,
[data-theme='light'] .lang-card,
[data-theme='light'] .scenario-card {
  background: rgba(255, 255, 255, 0.7);
  border-color: rgba(0, 0, 0, 0.08);
}
[data-theme='light'] .pronunciation-bar {
  background: rgba(255, 255, 255, 0.8);
  border-color: rgba(0, 0, 0, 0.08);
}
[data-theme='light'] .avatar-orb {
  background: linear-gradient(135deg, #e8edf5, #d0d8e8);
}

/* Theme toggle animation */
#theme-btn svg {
  transition: transform 0.3s ease;
}
[data-theme='light'] #theme-btn svg {
  transform: rotate(180deg);
}

/* ============================================
   LANGUAGE CARDS
   ============================================ */
.lang-cards {
  display: flex;
  gap: 10px;
  justify-content: center;
  flex-wrap: wrap;
}
.lang-card {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 6px;
  padding: 14px 18px;
  background: var(--bg-glass);
  -webkit-backdrop-filter: blur(10px);
  backdrop-filter: blur(10px);
  border: 1px solid var(--border-glass);
  border-radius: var(--radius-md);
  cursor: pointer;
  transition: all var(--transition-normal);
  color: var(--text-secondary);
  font-family: var(--font-body);
  min-width: 90px;
}
.lang-card:hover {
  background: var(--bg-glass-hover);
  border-color: var(--accent);
  transform: translateY(-2px);
}
.lang-card.active {
  background: rgba(99, 179, 237, 0.12);
  border-color: var(--accent);
  color: var(--text-primary);
  box-shadow: var(--shadow-glow);
}
.lang-flag {
  font-size: 1.8rem;
}
.lang-name {
  font-size: 0.8rem;
  font-weight: 600;
}

/* ============================================
   MODE TOGGLE (Topics / Role-Play)
   ============================================ */
.mode-toggle {
  display: flex;
  gap: 8px;
  justify-content: center;
  margin-bottom: 10px;
}
.mode-btn {
  padding: 10px 24px;
  border-radius: var(--radius-full);
  background: var(--bg-glass);
  border: 1px solid var(--border-glass);
  color: var(--text-muted);
  cursor: pointer;
  font-family: var(--font-body);
  font-size: 0.85rem;
  font-weight: 500;
  transition: all var(--transition-normal);
}
.mode-btn:hover {
  background: var(--bg-glass-hover);
  color: var(--text-primary);
}
.mode-btn.active {
  background: linear-gradient(135deg, var(--accent), var(--accent-2));
  color: white;
  border-color: transparent;
  box-shadow: 0 4px 15px var(--accent-glow);
}

/* ============================================
   SCENARIO GRID
   ============================================ */
.scenario-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 8px;
}
.scenario-card {
  background: var(--bg-glass);
  -webkit-backdrop-filter: blur(10px);
  backdrop-filter: blur(10px);
  border: 1px solid var(--border-glass);
  border-radius: var(--radius-md);
  padding: 14px 10px;
  cursor: pointer;
  text-align: center;
  transition: all var(--transition-normal);
  color: var(--text-secondary);
  font-family: var(--font-body);
}
.scenario-card:hover {
  transform: translateY(-2px);
  background: var(--bg-glass-hover);
  border-color: var(--accent);
}
.scenario-card.active {
  background: rgba(99, 179, 237, 0.12);
  border-color: var(--accent);
  color: var(--text-primary);
  box-shadow: var(--shadow-glow);
}
.scenario-icon {
  font-size: 1.5rem;
  display: block;
  margin-bottom: 6px;
}
.scenario-name {
  font-size: 0.78rem;
  font-weight: 600;
}
.scenario-desc {
  font-size: 0.65rem;
  color: var(--text-muted);
  margin-top: 3px;
}

/* ============================================
   XP / LEVEL / STREAK DISPLAYS
   ============================================ */
.xp-display {
  display: flex;
  align-items: center;
  gap: 6px;
  padding: 4px 10px;
  border-radius: var(--radius-full);
  background: var(--bg-glass);
  border: 1px solid var(--border-glass);
  cursor: pointer;
}
.xp-level {
  font-size: 0.72rem;
  font-weight: 700;
  background: linear-gradient(135deg, var(--accent), var(--accent-2));
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}
.xp-bar-mini {
  width: 40px;
  height: 4px;
  border-radius: 2px;
  background: var(--bg-glass);
  overflow: hidden;
}
.xp-bar-mini-fill {
  height: 100%;
  border-radius: 2px;
  background: linear-gradient(90deg, var(--accent), var(--accent-2));
  transition: width 0.5s ease;
}
.xp-value {
  font-size: 0.68rem;
  color: var(--text-muted);
  font-family: var(--font-mono);
}
.streak-display {
  font-size: 0.75rem;
  font-weight: 600;
  padding: 4px 8px;
  border-radius: var(--radius-full);
  background: var(--bg-glass);
  border: 1px solid var(--border-glass);
  cursor: pointer;
}

/* XP Popup */
.xp-popup {
  position: fixed;
  top: 60px;
  right: 20px;
  z-index: 500;
  padding: 8px 16px;
  border-radius: var(--radius-md);
  background: linear-gradient(135deg, var(--accent), var(--accent-2));
  color: white;
  font-weight: 700;
  font-size: 0.9rem;
  opacity: 0;
  transform: translateY(20px);
  pointer-events: none;
  transition: all 0.3s ease;
  box-shadow: 0 4px 20px var(--accent-glow);
}
.xp-popup.show {
  opacity: 1;
  transform: translateY(0);
  animation: xpPop 1.5s ease forwards;
}
@keyframes xpPop {
  0% {
    opacity: 0;
    transform: translateY(20px) scale(0.8);
  }
  20% {
    opacity: 1;
    transform: translateY(0) scale(1.1);
  }
  40% {
    transform: translateY(0) scale(1);
  }
  80% {
    opacity: 1;
    transform: translateY(-10px);
  }
  100% {
    opacity: 0;
    transform: translateY(-30px) scale(0.8);
  }
}

/* ============================================
   EXERCISES MODAL
   ============================================ */
.exercises-card {
  max-width: 520px;
  width: 95%;
}
.exercise-types {
  display: flex;
  flex-wrap: wrap;
  gap: 6px;
  margin-bottom: 16px;
}
.ex-type-btn {
  padding: 8px 14px;
  border-radius: var(--radius-full);
  background: var(--bg-glass);
  border: 1px solid var(--border-glass);
  color: var(--text-muted);
  cursor: pointer;
  font-family: var(--font-body);
  font-size: 0.78rem;
  font-weight: 500;
  transition: all 0.2s;
}
.ex-type-btn:hover {
  background: var(--bg-glass-hover);
  color: var(--text-primary);
}
.ex-type-btn.active {
  background: linear-gradient(135deg, var(--accent), var(--accent-2));
  color: white;
  border-color: transparent;
}
.exercise-area {
  min-height: 200px;
  padding: 16px;
  background: var(--bg-glass);
  border: 1px solid var(--border-glass);
  border-radius: var(--radius-md);
  margin-bottom: 14px;
}
.exercise-question {
  font-size: 1rem;
  color: var(--text-primary);
  line-height: 1.7;
  margin-bottom: 16px;
  font-weight: 500;
}
.exercise-options {
  display: flex;
  flex-direction: column;
  gap: 8px;
}
.exercise-option {
  padding: 12px 16px;
  background: var(--bg-glass);
  border: 1px solid var(--border-glass);
  border-radius: var(--radius-sm);
  cursor: pointer;
  font-family: var(--font-body);
  font-size: 0.88rem;
  color: var(--text-secondary);
  transition: all 0.2s;
  text-align: left;
}
.exercise-option:hover:not(.disabled) {
  background: var(--bg-glass-hover);
  border-color: var(--accent);
  transform: translateX(4px);
}
.exercise-option.correct {
  background: rgba(72, 187, 120, 0.15);
  border-color: var(--success);
  color: var(--success);
}
.exercise-option.wrong {
  background: rgba(252, 129, 129, 0.15);
  border-color: var(--error);
  color: var(--error);
}
.exercise-option.disabled {
  pointer-events: none;
  opacity: 0.7;
}
.exercise-input-area {
  display: flex;
  gap: 8px;
  align-items: center;
}
.exercise-input {
  flex: 1;
  padding: 10px 14px;
  background: var(--bg-glass);
  border: 1px solid var(--border-glass);
  border-radius: var(--radius-sm);
  color: var(--text-primary);
  font-family: var(--font-body);
  font-size: 0.88rem;
  outline: none;
  transition: border-color 0.2s;
}
.exercise-input:focus {
  border-color: var(--accent);
}
.exercise-result {
  margin-top: 12px;
  padding: 10px 14px;
  border-radius: var(--radius-sm);
  font-size: 0.88rem;
  font-weight: 500;
  text-align: center;
}
.exercise-result.correct {
  background: rgba(72, 187, 120, 0.1);
  color: var(--success);
}
.exercise-result.wrong {
  background: rgba(252, 129, 129, 0.1);
  color: var(--error);
}
.exercise-explain {
  margin-top: 8px;
  padding: 10px;
  background: rgba(99, 179, 237, 0.08);
  border-left: 3px solid var(--accent);
  border-radius: 0 var(--radius-sm) var(--radius-sm) 0;
  font-size: 0.82rem;
  color: var(--text-muted);
  line-height: 1.5;
}
.exercise-footer {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding-top: 4px;
}
.exercise-progress,
.exercise-score {
  font-size: 0.78rem;
  color: var(--text-muted);
  font-family: var(--font-mono);
}
/* Sentence Reorder drag area */
.reorder-area {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
  min-height: 50px;
  padding: 12px;
  background: var(--bg-glass);
  border: 2px dashed var(--border-glass);
  border-radius: var(--radius-md);
  margin-bottom: 10px;
}
.reorder-word {
  padding: 8px 14px;
  background: rgba(99, 179, 237, 0.12);
  border: 1px solid rgba(99, 179, 237, 0.3);
  border-radius: var(--radius-full);
  font-size: 0.85rem;
  color: var(--accent-bright);
  cursor: pointer;
  transition: all 0.2s;
  user-select: none;
  font-family: var(--font-body);
  font-weight: 500;
}
.reorder-word:hover {
  transform: scale(1.05);
}
.reorder-word.placed {
  background: rgba(159, 122, 234, 0.12);
  border-color: rgba(159, 122, 234, 0.3);
  color: var(--accent-2);
}

/* ============================================
   BADGES
   ============================================ */
.badges-section h3 {
  font-size: 0.85rem;
  color: var(--text-muted);
  margin-bottom: 10px;
}
.badges-grid,
.badges-full-grid {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 10px;
}
.badge-item {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 4px;
  padding: 12px 8px;
  background: var(--bg-glass);
  border: 1px solid var(--border-glass);
  border-radius: var(--radius-md);
  text-align: center;
  transition: all 0.3s;
}
.badge-item.earned {
  border-color: var(--accent);
  box-shadow: 0 0 15px var(--accent-glow);
}
.badge-item.locked {
  opacity: 0.4;
  filter: grayscale(1);
}
.badge-icon {
  font-size: 1.5rem;
}
.badge-label {
  font-size: 0.68rem;
  font-weight: 600;
  color: var(--text-secondary);
}
.badge-desc {
  font-size: 0.58rem;
  color: var(--text-muted);
}

/* ============================================
   SUMMARY ENHANCEMENTS
   ============================================ */
.summary-actions {
  display: flex;
  gap: 10px;
  margin-top: 14px;
}
.btn-primary {
  padding: 10px 20px;
  border-radius: var(--radius-full);
  background: linear-gradient(135deg, var(--accent), var(--accent-2));
  color: white;
  font-weight: 600;
  font-size: 0.85rem;
  border: none;
  cursor: pointer;
  transition: all 0.2s;
  font-family: var(--font-body);
}
.btn-primary:hover {
  transform: translateY(-1px);
  box-shadow: 0 4px 15px var(--accent-glow);
}
.btn-secondary {
  padding: 10px 20px;
  border-radius: var(--radius-full);
  background: var(--bg-glass);
  border: 1px solid var(--border-glass);
  color: var(--text-secondary);
  font-weight: 500;
  font-size: 0.85rem;
  cursor: pointer;
  transition: all 0.2s;
  font-family: var(--font-body);
}
.btn-secondary:hover {
  background: var(--bg-glass-hover);
  border-color: var(--accent);
}

/* ============================================
   AUTH MODAL
   ============================================ */
.auth-card {
  max-width: 460px;
}
.auth-tabs {
  display: flex;
  gap: 8px;
  margin-bottom: 14px;
}
.auth-tab {
  flex: 1;
  padding: 10px 12px;
  border-radius: var(--radius-sm);
  border: 1px solid var(--border-glass);
  background: var(--bg-glass);
  color: var(--text-secondary);
  cursor: pointer;
  font-family: var(--font-body);
}
.auth-tab.active {
  border-color: var(--accent);
  color: var(--accent-bright);
  background: var(--bg-glass-hover);
}
.auth-panel {
  display: flex;
  flex-direction: column;
  gap: 8px;
}
.auth-otp-box {
  margin-top: 8px;
  border-top: 1px solid var(--border-glass);
  padding-top: 10px;
}
.auth-actions {
  display: flex;
  gap: 8px;
}
.auth-current {
  margin-top: 10px;
  font-size: 0.8rem;
  color: var(--text-secondary);
}
.auth-footer {
  margin-top: 10px;
}
.auth-standalone {
  max-width: 460px;
}
.auth-page-panel {
  margin-top: 10px;
}
.auth-switch-line {
  margin-top: 14px;
  font-size: 0.82rem;
  color: var(--text-secondary);
}

/* ============================================
   RESPONSIVE ADJUSTMENTS (Phase 3)
   ============================================ */
@media (max-width: 600px) {
  .lang-cards {
    gap: 6px;
    flex-wrap: wrap;
    justify-content: center;
  }
  .lang-card {
    padding: 10px 12px;
    min-width: 70px;
    flex: 1 1 calc(33% - 10px);
  }
  .lang-flag {
    font-size: 1.4rem;
  }
  .lang-name {
    font-size: 0.7rem;
  }
  .level-cards {
    flex-wrap: wrap;
  }
  .level-card {
    flex: 1 1 calc(50% - 10px);
    font-size: 0.8rem;
    padding: 10px 16px;
  }
  .topic-grid {
    grid-template-columns: repeat(2, 1fr);
  }
  .scenario-grid {
    grid-template-columns: repeat(2, 1fr);
  }
  .badges-grid,
  .badges-full-grid {
    grid-template-columns: repeat(3, 1fr);
  }
  .exercise-types {
    gap: 4px;
    flex-wrap: wrap;
    justify-content: center;
  }
  .ex-type-btn {
    padding: 6px 10px;
    font-size: 0.72rem;
    flex: 1 1 auto;
  }
  .xp-display {
    padding: 3px 6px;
  }
  .xp-bar-mini {
    width: 30px;
  }
  .xp-value {
    display: none;
  }
  .streak-display {
    font-size: 0.68rem;
  }
  .session-stats {
    gap: 6px;
  }
  .side-panel {
    width: 100%;
    right: -100%;
  }
  .side-panel:not(.hidden) {
    right: 0;
  }
  .onboarding-content {
    min-height: 100vh;
    padding: 24px 4px 24px 4px;
    box-sizing: border-box;
    position: static;
    transform: none;
    left: 0;
    width: 100%;
    max-width: 100vw;
  }
}
@media (max-height: 700px) {
  .onboarding-screen {
    align-items: flex-start;
    padding-top: 20px;
  }
}

/* ============================================
   MOBILE OPTIMIZATIONS (FINAL POLISH)
   ============================================ */

/* Hide developer controls globally */
.stt-btn,
#stt-btn {
  display: none !important;
}

/* Mobile specific tweaks for professional feel */
@media (max-width: 768px) {
  /* Simplified Header */
  .app-header {
    padding: 8px 12px;
    background: rgba(10, 14, 26, 0.98);
    backdrop-filter: blur(12px);
  }

  .header-left {
    flex: 1;
    overflow: hidden;
  }
  .header-title {
    font-size: 1.1rem;
    white-space: nowrap;
    letter-spacing: -0.5px;
  }

  /* Hide non-essential status text to declutter */
  .header-status {
    display: none !important;
  }

  /* Compact Right Header */
  .header-right {
    gap: 8px;
  }

  /* Hide textual stats on mobile */
  .session-stats {
    display: none !important;
  }

  /* Make XP bar unobtrusive */
  .xp-display {
    padding: 0;
    background: transparent;
    border: none;
    box-shadow: none;
  }
  .xp-level {
    font-size: 0.75rem;
    color: var(--accent);
    font-weight: 700;
  }
  .xp-bar-mini {
    display: none;
  }
  .xp-value {
    display: none !important;
  }

  /* Streak icon only */
  .streak-display {
    background: transparent;
    border: none;
    padding: 0;
    font-size: 0.9rem;
  }

  /* Better Controls Bar for Thumb Reach */
  .controls-bar {
    padding: 12px 14px;
    gap: 12px;
    background: rgba(17, 24, 39, 0.95);
    border-top: 1px solid var(--border-glass);
    padding-bottom: max(12px, env(safe-area-inset-bottom));
    box-shadow: 0 -4px 20px rgba(0, 0, 0, 0.4);
  }

  /* Prominent Mic Button */
  .mic-btn {
    width: 60px;
    height: 60px;
    border-radius: var(--radius-full);
    background: var(--bg-secondary);
    border: 2px solid var(--accent);
    box-shadow: 0 4px 15px rgba(0, 0, 0, 0.3);
  }
  .mic-btn.active {
    background: rgba(252, 129, 129, 0.15);
    border-color: var(--error);
    box-shadow: 0 0 25px rgba(252, 129, 129, 0.5);
    animation: pulseMic 1.5s infinite;
  }

  /* Adjust Chat Area */
  .chat-panel {
    padding: 15px 15px 100px 15px;
  }

  /* Chat Bubbles - cleaner look */
  .message {
    font-size: 0.95rem;
    padding: 12px 16px;
    max-width: 88%;
    border-radius: 18px;
    line-height: 1.5;
  }

  /* Avatar Container - slightly smaller */
  .avatar-container {
    height: 140px;
    margin-top: 0;
    margin-bottom: 0;
  }
  .avatar-orb {
    width: 90px;
    height: 90px;
  }
  .state-label {
    opacity: 0;
    display: none;
  }

  /* Hide Waveform on mobile */
  .waveform-canvas {
    display: none !important;
  }

  /* Hide particles by default on mobile for performance */
  #particles-canvas {
    opacity: 0.2;
  }
}

@keyframes pulseMic {
  0% {
    transform: scale(1);
    box-shadow: 0 0 0 0 rgba(252, 129, 129, 0.7);
  }
  70% {
    transform: scale(1.05);
    box-shadow: 0 0 0 10px rgba(252, 129, 129, 0);
  }
  100% {
    transform: scale(1);
    box-shadow: 0 0 0 0 rgba(252, 129, 129, 0);
  }
}

/* ====================================================
   BOTTOM NAVIGATION BAR
   ==================================================== */
.bottom-nav {
  position: fixed;
  bottom: 0;
  left: 50%;
  transform: translateX(-50%);
  width: 100%;
  max-width: 480px;
  background: rgba(8, 14, 28, 0.96);
  border-top: 1px solid rgba(99, 179, 237, 0.14);
  backdrop-filter: blur(20px);
  -webkit-backdrop-filter: blur(20px);
  display: flex;
  align-items: stretch;
  z-index: 200;
  padding-bottom: env(safe-area-inset-bottom, 0px);
}

.nav-tab {
  flex: 1;
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  gap: 3px;
  padding: 10px 4px 8px;
  background: none;
  border: none;
  cursor: pointer;
  color: var(--text-muted);
  transition: color 0.2s;
  position: relative;
}

.nav-tab::before {
  content: '';
  position: absolute;
  top: 0;
  left: 20%;
  right: 20%;
  height: 2px;
  background: var(--accent);
  border-radius: 0 0 3px 3px;
  transform: scaleX(0);
  transition: transform 0.25s cubic-bezier(0.4, 0, 0.2, 1);
}

.nav-tab.active {
  color: var(--accent);
}

.nav-tab.active::before {
  transform: scaleX(1);
}

.nav-tab-icon {
  font-size: 1.3rem;
  line-height: 1;
}

.nav-tab-label {
  font-size: 0.65rem;
  font-weight: 600;
  letter-spacing: 0.04em;
  text-transform: uppercase;
}

/* ====================================================
   GENERIC APP SCREEN (Stories / Flashcards / Progress)
   ==================================================== */
.app-screen {
  position: fixed;
  inset: 0;
  background: var(--bg-primary);
  z-index: 100;
  display: flex;
  flex-direction: column;
  overflow-y: auto;
  overflow-x: hidden;
  padding-bottom: calc(60px + env(safe-area-inset-bottom, 0px));
  max-width: 480px;
  left: 50%;
  transform: translateX(-50%);
}

.screen-header {
  padding: 20px 16px 12px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  flex-wrap: wrap;
  gap: 10px;
  border-bottom: 1px solid var(--border-glass);
  position: sticky;
  top: 0;
  background: rgba(10,14,26,0.95);
  backdrop-filter: blur(12px);
  z-index: 10;
}

.screen-title {
  font-size: 1.25rem;
  font-weight: 700;
  color: var(--text-primary);
}

/* ====================================================
   STORIES SCREEN
   ==================================================== */
.story-level-tabs {
  display: flex;
  gap: 6px;
}

.story-lvl-btn {
  padding: 5px 10px;
  border-radius: 20px;
  border: 1px solid var(--border-glass);
  background: var(--bg-glass);
  color: var(--text-secondary);
  font-size: 0.72rem;
  font-weight: 600;
  cursor: pointer;
  transition: all 0.2s;
}

.story-lvl-btn.active {
  background: var(--accent-dim);
  border-color: var(--accent);
  color: var(--accent-bright);
}

.story-topic-row {
  display: flex;
  gap: 8px;
  padding: 12px 16px;
  overflow-x: auto;
  scrollbar-width: none;
  flex-shrink: 0;
}

.story-topic-row::-webkit-scrollbar { display: none; }

.story-topic-chip {
  white-space: nowrap;
  padding: 6px 13px;
  border-radius: 20px;
  border: 1px solid var(--border-glass);
  background: var(--bg-glass);
  color: var(--text-secondary);
  font-size: 0.78rem;
  cursor: pointer;
  transition: all 0.2s;
  flex-shrink: 0;
}

.story-topic-chip.active {
  background: rgba(159,122,234,0.2);
  border-color: var(--accent-2);
  color: #c4b5fd;
}

.story-image-wrap {
  position: relative;
  margin: 0 16px 12px;
  border-radius: var(--radius-lg);
  overflow: hidden;
  min-height: 180px;
  background: var(--bg-secondary);
  flex-shrink: 0;
}

.story-image-placeholder {
  display: flex;
  align-items: center;
  justify-content: center;
  min-height: 180px;
}

.story-placeholder-inner {
  text-align: center;
  padding: 24px 20px;
  color: var(--text-muted);
}

.story-placeholder-inner p {
  margin: 10px 0 18px;
  font-size: 0.88rem;
  line-height: 1.6;
}

.story-gen-btn {
  padding: 10px 22px;
  font-size: 0.9rem;
}

.story-image {
  width: 100%;
  height: 210px;
  object-fit: cover;
  display: block;
  border-radius: var(--radius-lg);
  transition: opacity 0.4s;
}

.story-image-shimmer {
  position: absolute;
  inset: 0;
  background: linear-gradient(90deg, var(--bg-secondary) 25%, rgba(255,255,255,0.06) 50%, var(--bg-secondary) 75%);
  background-size: 200%;
  animation: shimmer 1.5s infinite;
  border-radius: var(--radius-lg);
}

@keyframes shimmer {
  0%   { background-position: 200% center; }
  100% { background-position: -200% center; }
}

.story-card {
  margin: 0 16px 20px;
  padding: 18px;
  background: var(--bg-card);
  border: 1px solid var(--border-glass);
  border-radius: var(--radius-lg);
  flex-shrink: 0;
}

.story-card-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  margin-bottom: 12px;
}

.story-title {
  font-size: 1.1rem;
  font-weight: 700;
  color: var(--accent-bright);
  flex: 1;
}

.story-actions {
  display: flex;
  gap: 8px;
}

.story-action-btn {
  background: var(--bg-glass);
  border: 1px solid var(--border-glass);
  border-radius: 10px;
  padding: 6px 10px;
  font-size: 1rem;
  cursor: pointer;
  transition: background 0.2s;
  color: var(--text-primary);
}

.story-action-btn:hover {
  background: var(--bg-glass-hover);
}

.story-body {
  font-size: 0.95rem;
  line-height: 1.85;
  color: var(--text-primary);
  margin-bottom: 18px;
}

.story-body .story-word-highlight {
  background: rgba(99,179,237,0.15);
  border-bottom: 2px solid var(--accent);
  border-radius: 3px;
  cursor: pointer;
  padding: 0 2px;
  transition: background 0.15s;
}

.story-body .story-word-highlight:hover {
  background: rgba(99,179,237,0.3);
}

.story-vocab-title {
  font-size: 0.85rem;
  font-weight: 700;
  color: var(--text-secondary);
  text-transform: uppercase;
  letter-spacing: 0.08em;
  margin-bottom: 10px;
}

.story-vocab-grid {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 8px;
  margin-bottom: 16px;
}

.story-vocab-item {
  background: var(--bg-glass);
  border: 1px solid var(--border-glass);
  border-radius: var(--radius-md);
  padding: 10px 12px;
  cursor: pointer;
  transition: all 0.2s;
}

.story-vocab-item:hover {
  border-color: var(--accent);
  background: rgba(99,179,237,0.08);
}

.story-vocab-word {
  font-weight: 700;
  font-size: 0.92rem;
  color: var(--accent-bright);
}

.story-vocab-translation {
  font-size: 0.78rem;
  color: var(--text-muted);
  margin-top: 2px;
}

.story-vocab-example {
  font-size: 0.75rem;
  color: var(--text-secondary);
  margin-top: 5px;
  font-style: italic;
  line-height: 1.4;
}

.story-practice-btn {
  width: 100%;
  padding: 12px;
}

/* ====================================================
   FLASHCARDS / SRS SCREEN
   ==================================================== */
.fc-deck-select {
  display: flex;
  gap: 6px;
}

.fc-deck-btn {
  padding: 5px 12px;
  border-radius: 20px;
  border: 1px solid var(--border-glass);
  background: var(--bg-glass);
  color: var(--text-secondary);
  font-size: 0.76rem;
  font-weight: 600;
  cursor: pointer;
  transition: all 0.2s;
}

.fc-deck-btn.active {
  background: rgba(159,122,234,0.2);
  border-color: var(--accent-2);
  color: #c4b5fd;
}

.fc-stats-row {
  display: flex;
  gap: 8px;
  padding: 10px 16px;
  flex-shrink: 0;
}

.fc-stat-chip {
  flex: 1;
  text-align: center;
  background: var(--bg-glass);
  border: 1px solid var(--border-glass);
  border-radius: var(--radius-md);
  padding: 8px 4px;
  font-size: 0.8rem;
  color: var(--text-secondary);
}

.srs-card-wrap {
  flex: 1;
  display: flex;
  align-items: center;
  justify-content: center;
  padding: 16px;
  perspective: 1000px;
  min-height: 260px;
}

.srs-empty-state {
  text-align: center;
  padding: 30px 20px;
  color: var(--text-muted);
}

.srs-empty-state h3 {
  margin: 10px 0 8px;
  color: var(--text-secondary);
}

.srs-empty-state p {
  font-size: 0.88rem;
  line-height: 1.6;
}

.srs-card {
  width: 100%;
  max-width: 340px;
  aspect-ratio: 1.6;
  cursor: pointer;
  transform-style: preserve-3d;
  transition: transform 0.55s cubic-bezier(0.4, 0, 0.2, 1);
  position: relative;
}

.srs-card.flipped {
  transform: rotateY(180deg);
}

.srs-front,
.srs-back {
  position: absolute;
  inset: 0;
  border-radius: var(--radius-xl);
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  padding: 24px;
  backface-visibility: hidden;
  -webkit-backface-visibility: hidden;
}

.srs-front {
  background: linear-gradient(135deg, rgba(26,32,56,0.95) 0%, rgba(17,24,39,0.95) 100%);
  border: 1px solid rgba(99,179,237,0.2);
  box-shadow: 0 8px 40px rgba(0,0,0,0.5), 0 0 0 1px rgba(99,179,237,0.08);
}

.srs-back {
  background: linear-gradient(135deg, rgba(42,20,70,0.95) 0%, rgba(25,15,50,0.95) 100%);
  border: 1px solid rgba(159,122,234,0.25);
  box-shadow: 0 8px 40px rgba(0,0,0,0.5), 0 0 0 1px rgba(159,122,234,0.1);
  transform: rotateY(180deg);
}

.srs-card-tag {
  font-size: 0.65rem;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 0.15em;
  color: var(--text-muted);
  margin-bottom: 8px;
}

.srs-card-word {
  font-size: 2rem;
  font-weight: 800;
  color: var(--accent-bright);
  text-align: center;
  line-height: 1.2;
}

.srs-card-hint {
  font-size: 0.72rem;
  color: var(--text-muted);
  margin-top: 12px;
}

.srs-card-translation {
  font-size: 1.4rem;
  font-weight: 700;
  color: #c4b5fd;
  text-align: center;
  margin-bottom: 10px;
}

.srs-card-example {
  font-size: 0.82rem;
  color: var(--text-secondary);
  text-align: center;
  font-style: italic;
  line-height: 1.5;
}

.srs-speak-btn {
  margin-top: 12px;
  background: rgba(159,122,234,0.2);
  border: 1px solid rgba(159,122,234,0.3);
  border-radius: 20px;
  color: #c4b5fd;
  font-size: 0.78rem;
  padding: 5px 14px;
  cursor: pointer;
}

.srs-progress-dots {
  position: absolute;
  bottom: -22px;
  left: 50%;
  transform: translateX(-50%);
  display: flex;
  gap: 5px;
}

.srs-dot {
  width: 6px;
  height: 6px;
  border-radius: 50%;
  background: var(--border-glass);
  transition: background 0.2s, transform 0.2s;
}

.srs-dot.active {
  background: var(--accent);
  transform: scale(1.3);
}

.srs-dot.done {
  background: var(--success);
}

.srs-rating-row {
  display: flex;
  gap: 8px;
  padding: 12px 16px 16px;
  flex-shrink: 0;
}

.srs-rate-btn {
  flex: 1;
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 3px;
  padding: 10px 4px;
  border-radius: var(--radius-md);
  border: 1px solid var(--border-glass);
  background: var(--bg-glass);
  cursor: pointer;
  font-size: 1.1rem;
  transition: all 0.2s;
  color: var(--text-primary);
}

.srs-rate-btn span {
  font-size: 0.65rem;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 0.06em;
  color: var(--text-muted);
}

.srs-rate-btn.again { border-color: rgba(252, 129, 129, 0.3); }
.srs-rate-btn.again:hover { background: rgba(252, 129, 129, 0.12); border-color: var(--error); }
.srs-rate-btn.hard  { border-color: rgba(246, 173, 85, 0.3); }
.srs-rate-btn.hard:hover  { background: rgba(246, 173, 85, 0.12); border-color: var(--warning); }
.srs-rate-btn.good  { border-color: rgba(99, 179, 237, 0.3); }
.srs-rate-btn.good:hover  { background: rgba(99, 179, 237, 0.12); border-color: var(--accent); }
.srs-rate-btn.easy  { border-color: rgba(104, 211, 145, 0.3); }
.srs-rate-btn.easy:hover  { background: rgba(104, 211, 145, 0.12); border-color: var(--success); }

/* ====================================================
   PROGRESS SCREEN
   ==================================================== */
.progress-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 10px;
  padding: 16px 16px 8px;
}

.prog-card {
  background: var(--bg-card);
  border: 1px solid var(--border-glass);
  border-radius: var(--radius-lg);
  padding: 16px 12px;
  text-align: center;
  transition: border-color 0.2s;
}

.prog-card:hover {
  border-color: var(--accent);
}

.prog-card.xp-card {
  grid-column: span 3;
  background: linear-gradient(135deg, rgba(10,18,40,0.95) 0%, rgba(26,32,56,0.95) 100%);
  border-color: rgba(99,179,237,0.2);
  padding: 20px 16px;
}

.prog-card-icon {
  font-size: 1.5rem;
  margin-bottom: 4px;
}

.prog-card-val {
  font-size: 1.6rem;
  font-weight: 800;
  color: var(--accent-bright);
  line-height: 1;
}

.xp-card .prog-card-val {
  font-size: 2.2rem;
  margin: 4px 0;
}

.prog-card-label {
  font-size: 0.7rem;
  font-weight: 600;
  color: var(--text-muted);
  text-transform: uppercase;
  letter-spacing: 0.08em;
  margin-top: 4px;
}

.prog-xp-bar {
  height: 6px;
  background: var(--bg-glass);
  border-radius: 3px;
  margin-top: 8px;
  overflow: hidden;
}

.prog-xp-fill {
  height: 100%;
  background: linear-gradient(90deg, var(--accent-dim), var(--accent));
  border-radius: 3px;
  transition: width 0.6s cubic-bezier(0.4, 0, 0.2, 1);
}

.leaderboard-section {
  margin: 8px 16px 16px;
  background: var(--bg-card);
  border: 1px solid var(--border-glass);
  border-radius: var(--radius-lg);
  overflow: hidden;
  flex-shrink: 0;
}

.lb-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 14px 16px;
  border-bottom: 1px solid var(--border-glass);
}

.lb-header h3 {
  font-size: 0.95rem;
  font-weight: 700;
}

.lb-refresh-btn {
  background: none;
  border: none;
  font-size: 1rem;
  cursor: pointer;
  color: var(--text-muted);
  transition: color 0.2s, transform 0.3s;
}

.lb-refresh-btn:hover {
  color: var(--accent);
  transform: rotate(180deg);
}

.lb-loading {
  padding: 20px;
  text-align: center;
  color: var(--text-muted);
  font-size: 0.85rem;
}

.lb-row {
  display: flex;
  align-items: center;
  gap: 10px;
  padding: 10px 16px;
  border-bottom: 1px solid var(--border-glass);
  transition: background 0.15s;
}

.lb-row:last-child { border-bottom: none; }
.lb-row:hover { background: var(--bg-glass); }
.lb-row.me { background: rgba(99,179,237,0.07); }

.lb-rank {
  width: 22px;
  font-size: 0.8rem;
  font-weight: 800;
  color: var(--text-muted);
  text-align: center;
  flex-shrink: 0;
}

.lb-rank.gold   { color: #fbbf24; }
.lb-rank.silver { color: #94a3b8; }
.lb-rank.bronze { color: #b45309; }

.lb-flag { font-size: 1.2rem; flex-shrink: 0; }

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

.lb-name {
  font-size: 0.88rem;
  font-weight: 600;
  color: var(--text-primary);
  white-space: nowrap;
  overflow: hidden;
  text-overflow: ellipsis;
}

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

.lb-xp {
  font-size: 0.85rem;
  font-weight: 700;
  color: var(--accent);
  flex-shrink: 0;
}

.badges-progress-section {
  margin: 0 16px 24px;
}

/* ====================================================
   LIGHT THEME OVERRIDES FOR NEW SCREENS
   ==================================================== */
[data-theme="light"] .app-screen {
  background: #f0f4ff;
}

[data-theme="light"] .screen-header {
  background: rgba(240,244,255,0.95);
  border-bottom-color: rgba(100,130,220,0.2);
}

[data-theme="light"] .screen-title { color: #111827; }

[data-theme="light"] .story-lvl-btn,
[data-theme="light"] .story-topic-chip,
[data-theme="light"] .fc-deck-btn,
[data-theme="light"] .fc-stat-chip {
  background: #ffffff;
  border-color: rgba(100,130,220,0.25);
  color: #374151;
}

[data-theme="light"] .story-card,
[data-theme="light"] .lb-row,
[data-theme="light"] .prog-card,
[data-theme="light"] .leaderboard-section {
  background: #ffffff;
  border-color: rgba(100,130,220,0.2);
}

[data-theme="light"] .srs-front {
  background: linear-gradient(135deg, #e8eef8 0%, #dce7f7 100%);
  border-color: rgba(100,130,220,0.3);
}

[data-theme="light"] .srs-back {
  background: linear-gradient(135deg, #ede9fe 0%, #ddd6fe 100%);
  border-color: rgba(139,92,246,0.3);
}

[data-theme="light"] .srs-card-word { color: #1d4ed8; }
[data-theme="light"] .srs-card-translation { color: #6d28d9; }
[data-theme="light"] .srs-card-example { color: #374151; }

[data-theme="light"] .bottom-nav {
  background: rgba(240,244,255,0.97);
  border-top-color: rgba(100,130,220,0.2);
}

[data-theme="light"] .nav-tab { color: #9ca3af; }
[data-theme="light"] .nav-tab.active { color: #2563eb; }
[data-theme="light"] .nav-tab::before { background: #2563eb; }

[data-theme="light"] .lb-name { color: #111827; }
[data-theme="light"] .prog-card-val { color: #1d4ed8; }

/* ====================================================
   APP CONTAINER PADDING FOR BOTTOM NAV
   ==================================================== */
.app-container.has-bottom-nav {
  padding-bottom: calc(60px + env(safe-area-inset-bottom, 0px));
}