/* ============================================
   MOS-READY Design System
   Gen-Z Aesthetic: Glassmorphism, Vibrant Gradients, Dark Mode
   ============================================ */

/* ---------- Google Fonts ---------- */
@import url('https://fonts.googleapis.com/css2?family=Inter:wght@300;400;500;600;700;800;900&family=Space+Grotesk:wght@400;500;600;700&display=swap');

/* ---------- CSS Custom Properties ---------- */
:root {
  /* Primary Palette */
  --primary-50: #f0f0ff;
  --primary-100: #e0e0ff;
  --primary-200: #c7c4ff;
  --primary-300: #a5a0ff;
  --primary-400: #8b7fff;
  --primary-500: #7c5cfc;
  --primary-600: #6d3df4;
  --primary-700: #5e2de0;
  --primary-800: #4e25b8;
  --primary-900: #412396;

  /* Accent / Energy */
  --accent-cyan: #00f5d4;
  --accent-pink: #f72585;
  --accent-orange: #ff6b35;
  --accent-yellow: #fee440;
  --accent-lime: #a8e10c;

  /* Neutrals (Dark Mode First) */
  --bg-primary: #0a0a1a;
  --bg-secondary: #12122a;
  --bg-tertiary: #1a1a3e;
  --bg-card: rgba(26, 26, 62, 0.6);
  --bg-glass: rgba(255, 255, 255, 0.05);
  --bg-glass-hover: rgba(255, 255, 255, 0.08);
  --bg-glass-active: rgba(255, 255, 255, 0.12);

  --text-primary: #f0f0ff;
  --text-secondary: #a0a0c0;
  --text-tertiary: #6a6a8e;
  --text-inverse: #0a0a1a;

  /* Borders */
  --border-subtle: rgba(255, 255, 255, 0.06);
  --border-default: rgba(255, 255, 255, 0.1);
  --border-strong: rgba(255, 255, 255, 0.2);

  /* Gradients */
  --gradient-primary: linear-gradient(135deg, #7c5cfc 0%, #f72585 100%);
  --gradient-accent: linear-gradient(135deg, #00f5d4 0%, #7c5cfc 100%);
  --gradient-warm: linear-gradient(135deg, #ff6b35 0%, #f72585 100%);
  --gradient-cool: linear-gradient(135deg, #00f5d4 0%, #3a86ff 100%);
  --gradient-gold: linear-gradient(135deg, #fee440 0%, #ff6b35 100%);
  --gradient-mesh: radial-gradient(at 20% 80%, rgba(124, 92, 252, 0.15) 0%, transparent 50%),
                   radial-gradient(at 80% 20%, rgba(247, 37, 133, 0.1) 0%, transparent 50%),
                   radial-gradient(at 50% 50%, rgba(0, 245, 212, 0.05) 0%, transparent 50%);

  /* Shadows */
  --shadow-sm: 0 2px 8px rgba(0, 0, 0, 0.3);
  --shadow-md: 0 4px 16px rgba(0, 0, 0, 0.4);
  --shadow-lg: 0 8px 32px rgba(0, 0, 0, 0.5);
  --shadow-glow-primary: 0 0 20px rgba(124, 92, 252, 0.3);
  --shadow-glow-accent: 0 0 20px rgba(0, 245, 212, 0.3);
  --shadow-glow-pink: 0 0 20px rgba(247, 37, 133, 0.3);

  /* Spacing */
  --space-xs: 4px;
  --space-sm: 8px;
  --space-md: 16px;
  --space-lg: 24px;
  --space-xl: 32px;
  --space-2xl: 48px;
  --space-3xl: 64px;

  /* Border Radius */
  --radius-sm: 8px;
  --radius-md: 12px;
  --radius-lg: 16px;
  --radius-xl: 24px;
  --radius-full: 9999px;

  /* Typography */
  --font-primary: 'Inter', -apple-system, BlinkMacSystemFont, sans-serif;
  --font-display: 'Space Grotesk', 'Inter', sans-serif;

  --text-xs: 0.75rem;
  --text-sm: 0.875rem;
  --text-base: 1rem;
  --text-lg: 1.125rem;
  --text-xl: 1.25rem;
  --text-2xl: 1.5rem;
  --text-3xl: 2rem;
  --text-4xl: 2.5rem;
  --text-5xl: 3.5rem;

  /* Transitions */
  --transition-fast: 150ms cubic-bezier(0.4, 0, 0.2, 1);
  --transition-base: 250ms cubic-bezier(0.4, 0, 0.2, 1);
  --transition-slow: 400ms cubic-bezier(0.4, 0, 0.2, 1);
  --transition-bounce: 500ms cubic-bezier(0.34, 1.56, 0.64, 1);

  /* Layout */
  --sidebar-width: 260px;
  --sidebar-collapsed: 72px;
  --topbar-height: 64px;
  --content-max-width: 1200px;

  /* Z-index */
  --z-sidebar: 100;
  --z-topbar: 200;
  --z-modal: 500;
  --z-toast: 600;
  --z-tooltip: 700;
}

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

html {
  font-size: 16px;
  scroll-behavior: smooth;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}

body {
  font-family: var(--font-primary);
  background: var(--bg-primary);
  color: var(--text-primary);
  line-height: 1.6;
  min-height: 100vh;
  overflow-x: hidden;
}

body::before {
  content: '';
  position: fixed;
  inset: 0;
  background: var(--gradient-mesh);
  pointer-events: none;
  z-index: 0;
}

a {
  color: var(--primary-400);
  text-decoration: none;
  transition: color var(--transition-fast);
}

a:hover {
  color: var(--accent-cyan);
}

img {
  max-width: 100%;
  display: block;
}

button {
  font-family: inherit;
  cursor: pointer;
  border: none;
  background: none;
  color: inherit;
}

input, textarea, select {
  font-family: inherit;
  font-size: inherit;
  color: inherit;
  background: var(--bg-glass);
  border: 1px solid var(--border-default);
  border-radius: var(--radius-md);
  padding: var(--space-sm) var(--space-md);
  transition: border-color var(--transition-fast), box-shadow var(--transition-fast);
}

input:focus, textarea:focus, select:focus {
  outline: none;
  border-color: var(--primary-500);
  box-shadow: var(--shadow-glow-primary);
}

/* ---------- Scrollbar ---------- */
::-webkit-scrollbar {
  width: 6px;
  height: 6px;
}

::-webkit-scrollbar-track {
  background: transparent;
}

::-webkit-scrollbar-thumb {
  background: var(--border-strong);
  border-radius: var(--radius-full);
}

::-webkit-scrollbar-thumb:hover {
  background: var(--primary-500);
}

/* ---------- Typography ---------- */
.heading-1 {
  font-family: var(--font-display);
  font-size: var(--text-4xl);
  font-weight: 800;
  line-height: 1.1;
  letter-spacing: -0.02em;
}

.heading-2 {
  font-family: var(--font-display);
  font-size: var(--text-3xl);
  font-weight: 700;
  line-height: 1.2;
  letter-spacing: -0.01em;
}

.heading-3 {
  font-family: var(--font-display);
  font-size: var(--text-2xl);
  font-weight: 600;
  line-height: 1.3;
}

.heading-4 {
  font-size: var(--text-xl);
  font-weight: 600;
  line-height: 1.4;
}

.text-gradient {
  background: var(--gradient-primary);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}

.text-gradient-accent {
  background: var(--gradient-accent);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}

.text-sm { font-size: var(--text-sm); }
.text-xs { font-size: var(--text-xs); }
.text-secondary { color: var(--text-secondary); }
.text-tertiary { color: var(--text-tertiary); }

/* ---------- Glass Card ---------- */
.glass-card {
  background: var(--bg-card);
  backdrop-filter: blur(20px);
  -webkit-backdrop-filter: blur(20px);
  border: 1px solid var(--border-subtle);
  border-radius: var(--radius-lg);
  padding: var(--space-lg);
  transition: transform var(--transition-base), box-shadow var(--transition-base), border-color var(--transition-base);
}

.glass-card:hover {
  border-color: var(--border-default);
  box-shadow: var(--shadow-md);
  transform: translateY(-2px);
}

.glass-card--flat {
  composes: glass-card;
}

.glass-card--flat:hover {
  transform: none;
}

/* ---------- Buttons ---------- */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: var(--space-sm);
  padding: 10px 20px;
  border-radius: var(--radius-md);
  font-weight: 600;
  font-size: var(--text-sm);
  transition: all var(--transition-base);
  position: relative;
  overflow: hidden;
  white-space: nowrap;
}

.btn::after {
  content: '';
  position: absolute;
  inset: 0;
  background: rgba(255, 255, 255, 0);
  transition: background var(--transition-fast);
}

.btn:hover::after {
  background: rgba(255, 255, 255, 0.1);
}

.btn:active {
  transform: scale(0.97);
}

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

.btn-primary:hover {
  box-shadow: 0 0 30px rgba(124, 92, 252, 0.5);
}

.btn-secondary {
  background: var(--bg-glass);
  border: 1px solid var(--border-default);
  color: var(--text-primary);
}

.btn-secondary:hover {
  border-color: var(--primary-500);
  background: var(--bg-glass-hover);
}

.btn-accent {
  background: var(--gradient-accent);
  color: var(--text-inverse);
  font-weight: 700;
}

.btn-ghost {
  background: transparent;
  color: var(--text-secondary);
}

.btn-ghost:hover {
  color: var(--text-primary);
  background: var(--bg-glass);
}

.btn-lg {
  padding: 14px 28px;
  font-size: var(--text-base);
  border-radius: var(--radius-lg);
}

.btn-sm {
  padding: 6px 14px;
  font-size: var(--text-xs);
}

.btn-icon {
  width: 40px;
  height: 40px;
  padding: 0;
  border-radius: var(--radius-md);
}

/* ---------- Badges ---------- */
.badge {
  display: inline-flex;
  align-items: center;
  gap: 4px;
  padding: 4px 10px;
  border-radius: var(--radius-full);
  font-size: var(--text-xs);
  font-weight: 600;
  letter-spacing: 0.02em;
}

.badge-primary {
  background: rgba(124, 92, 252, 0.15);
  color: var(--primary-300);
  border: 1px solid rgba(124, 92, 252, 0.3);
}

.badge-success {
  background: rgba(0, 245, 212, 0.1);
  color: var(--accent-cyan);
  border: 1px solid rgba(0, 245, 212, 0.2);
}

.badge-warning {
  background: rgba(254, 228, 64, 0.1);
  color: var(--accent-yellow);
  border: 1px solid rgba(254, 228, 64, 0.2);
}

.badge-danger {
  background: rgba(247, 37, 133, 0.1);
  color: var(--accent-pink);
  border: 1px solid rgba(247, 37, 133, 0.2);
}

.badge-xp {
  background: var(--gradient-gold);
  color: var(--text-inverse);
  font-weight: 700;
  border: none;
}

/* ---------- Progress Bar ---------- */
.progress-bar {
  width: 100%;
  height: 8px;
  background: var(--bg-glass);
  border-radius: var(--radius-full);
  overflow: hidden;
  position: relative;
}

.progress-bar__fill {
  height: 100%;
  border-radius: var(--radius-full);
  background: var(--gradient-primary);
  transition: width 600ms cubic-bezier(0.4, 0, 0.2, 1);
  position: relative;
}

.progress-bar__fill::after {
  content: '';
  position: absolute;
  right: 0;
  top: 0;
  height: 100%;
  width: 20px;
  background: rgba(255, 255, 255, 0.3);
  filter: blur(4px);
  animation: progress-glow 2s ease-in-out infinite;
}

@keyframes progress-glow {
  0%, 100% { opacity: 0.3; }
  50% { opacity: 1; }
}

.progress-bar--lg {
  height: 12px;
}

.progress-bar--accent .progress-bar__fill {
  background: var(--gradient-accent);
}

/* ---------- Progress Ring ---------- */
.progress-ring {
  position: relative;
  display: inline-flex;
  align-items: center;
  justify-content: center;
}

.progress-ring svg {
  transform: rotate(-90deg);
}

.progress-ring__bg {
  fill: none;
  stroke: var(--bg-glass);
  stroke-width: 6;
}

.progress-ring__fill {
  fill: none;
  stroke: url(#gradient-ring);
  stroke-width: 6;
  stroke-linecap: round;
  transition: stroke-dashoffset 600ms cubic-bezier(0.4, 0, 0.2, 1);
}

.progress-ring__text {
  position: absolute;
  font-family: var(--font-display);
  font-weight: 700;
  font-size: var(--text-lg);
}

/* ---------- XP Bar ---------- */
.xp-bar-container {
  display: flex;
  align-items: center;
  gap: var(--space-sm);
}

.xp-bar {
  flex: 1;
  height: 6px;
  background: var(--bg-glass);
  border-radius: var(--radius-full);
  overflow: hidden;
}

.xp-bar__fill {
  height: 100%;
  background: var(--gradient-gold);
  border-radius: var(--radius-full);
  transition: width 800ms cubic-bezier(0.34, 1.56, 0.64, 1);
}

.xp-label {
  font-size: var(--text-xs);
  font-weight: 700;
  color: var(--accent-yellow);
  min-width: 60px;
  text-align: right;
}

/* ---------- Stat Card ---------- */
.stat-card {
  background: var(--bg-card);
  backdrop-filter: blur(20px);
  border: 1px solid var(--border-subtle);
  border-radius: var(--radius-lg);
  padding: var(--space-lg);
  display: flex;
  flex-direction: column;
  gap: var(--space-sm);
  transition: all var(--transition-base);
}

.stat-card:hover {
  border-color: var(--border-default);
  transform: translateY(-2px);
}

.stat-card__icon {
  width: 44px;
  height: 44px;
  border-radius: var(--radius-md);
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 20px;
}

.stat-card__value {
  font-family: var(--font-display);
  font-size: var(--text-3xl);
  font-weight: 800;
  line-height: 1;
}

.stat-card__label {
  font-size: var(--text-sm);
  color: var(--text-secondary);
}

/* ---------- Navigation Tab ---------- */
.nav-tab {
  display: flex;
  align-items: center;
  gap: var(--space-sm);
  padding: 10px var(--space-md);
  border-radius: var(--radius-md);
  color: var(--text-secondary);
  font-weight: 500;
  font-size: var(--text-sm);
  transition: all var(--transition-fast);
  cursor: pointer;
  width: 100%;
  text-align: left;
}

.nav-tab:hover {
  background: var(--bg-glass-hover);
  color: var(--text-primary);
}

.nav-tab.active {
  background: rgba(124, 92, 252, 0.12);
  color: var(--primary-300);
  font-weight: 600;
}

.nav-tab.active::before {
  content: '';
  position: absolute;
  left: 0;
  top: 50%;
  transform: translateY(-50%);
  width: 3px;
  height: 24px;
  background: var(--gradient-primary);
  border-radius: 0 var(--radius-full) var(--radius-full) 0;
}

.nav-tab__icon {
  width: 20px;
  height: 20px;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 18px;
  flex-shrink: 0;
}

/* ---------- Modal ---------- */
.modal-overlay {
  position: fixed;
  inset: 0;
  background: rgba(0, 0, 0, 0.6);
  backdrop-filter: blur(8px);
  display: flex;
  align-items: center;
  justify-content: center;
  z-index: var(--z-modal);
  opacity: 0;
  pointer-events: none;
  transition: opacity var(--transition-base);
}

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

.modal {
  background: var(--bg-secondary);
  border: 1px solid var(--border-default);
  border-radius: var(--radius-xl);
  padding: var(--space-2xl);
  max-width: 520px;
  width: 90%;
  max-height: 85vh;
  overflow-y: auto;
  transform: scale(0.9) translateY(20px);
  transition: transform var(--transition-bounce);
  box-shadow: var(--shadow-lg);
}

.modal-overlay.active .modal {
  transform: scale(1) translateY(0);
}

.modal__header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  margin-bottom: var(--space-lg);
}

.modal__title {
  font-family: var(--font-display);
  font-size: var(--text-xl);
  font-weight: 700;
}

/* ---------- Toast ---------- */
.toast-container {
  position: fixed;
  bottom: var(--space-lg);
  right: var(--space-lg);
  z-index: var(--z-toast);
  display: flex;
  flex-direction: column-reverse;
  gap: var(--space-sm);
}

.toast {
  background: var(--bg-secondary);
  border: 1px solid var(--border-default);
  border-radius: var(--radius-md);
  padding: var(--space-md) var(--space-lg);
  display: flex;
  align-items: center;
  gap: var(--space-md);
  min-width: 300px;
  max-width: 420px;
  box-shadow: var(--shadow-lg);
  animation: toast-in 400ms cubic-bezier(0.34, 1.56, 0.64, 1);
}

.toast.toast-exit {
  animation: toast-out 300ms ease-in forwards;
}

.toast--xp {
  border-color: rgba(254, 228, 64, 0.3);
  background: linear-gradient(135deg, rgba(254, 228, 64, 0.1) 0%, var(--bg-secondary) 100%);
}

.toast--success {
  border-color: rgba(0, 245, 212, 0.3);
}

.toast--error {
  border-color: rgba(247, 37, 133, 0.3);
}

@keyframes toast-in {
  from { transform: translateX(100%); opacity: 0; }
  to { transform: translateX(0); opacity: 1; }
}

@keyframes toast-out {
  from { transform: translateX(0); opacity: 1; }
  to { transform: translateX(100%); opacity: 0; }
}

/* ---------- Animations ---------- */
@keyframes fade-in {
  from { opacity: 0; }
  to { opacity: 1; }
}

@keyframes slide-up {
  from { opacity: 0; transform: translateY(20px); }
  to { opacity: 1; transform: translateY(0); }
}

@keyframes slide-in-left {
  from { opacity: 0; transform: translateX(-20px); }
  to { opacity: 1; transform: translateX(0); }
}

@keyframes scale-in {
  from { opacity: 0; transform: scale(0.9); }
  to { opacity: 1; transform: scale(1); }
}

@keyframes float {
  0%, 100% { transform: translateY(0); }
  50% { transform: translateY(-6px); }
}

@keyframes pulse-glow {
  0%, 100% { box-shadow: 0 0 20px rgba(124, 92, 252, 0.2); }
  50% { box-shadow: 0 0 40px rgba(124, 92, 252, 0.4); }
}

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

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

@keyframes xp-pop {
  0% { transform: scale(0) rotate(-10deg); opacity: 0; }
  50% { transform: scale(1.2) rotate(5deg); opacity: 1; }
  100% { transform: scale(1) rotate(0deg); opacity: 1; }
}

.animate-fade-in { animation: fade-in 400ms ease-out; }
.animate-slide-up { animation: slide-up 500ms cubic-bezier(0.4, 0, 0.2, 1); }
.animate-scale-in { animation: scale-in 400ms cubic-bezier(0.34, 1.56, 0.64, 1); }
.animate-float { animation: float 3s ease-in-out infinite; }
.animate-pulse-glow { animation: pulse-glow 2s ease-in-out infinite; }

/* Stagger children */
.stagger-children > * {
  opacity: 0;
  animation: slide-up 400ms ease-out forwards;
}

.stagger-children > *:nth-child(1) { animation-delay: 50ms; }
.stagger-children > *:nth-child(2) { animation-delay: 100ms; }
.stagger-children > *:nth-child(3) { animation-delay: 150ms; }
.stagger-children > *:nth-child(4) { animation-delay: 200ms; }
.stagger-children > *:nth-child(5) { animation-delay: 250ms; }
.stagger-children > *:nth-child(6) { animation-delay: 300ms; }
.stagger-children > *:nth-child(7) { animation-delay: 350ms; }
.stagger-children > *:nth-child(8) { animation-delay: 400ms; }

/* ---------- Utilities ---------- */
.flex { display: flex; }
.flex-col { flex-direction: column; }
.flex-wrap { flex-wrap: wrap; }
.items-center { align-items: center; }
.justify-center { justify-content: center; }
.justify-between { justify-content: space-between; }
.gap-xs { gap: var(--space-xs); }
.gap-sm { gap: var(--space-sm); }
.gap-md { gap: var(--space-md); }
.gap-lg { gap: var(--space-lg); }
.gap-xl { gap: var(--space-xl); }
.gap-2xl { gap: var(--space-2xl); }

.grid { display: grid; }
.grid-2 { grid-template-columns: repeat(2, 1fr); }
.grid-3 { grid-template-columns: repeat(3, 1fr); }
.grid-4 { grid-template-columns: repeat(4, 1fr); }
.grid-auto { grid-template-columns: repeat(auto-fill, minmax(280px, 1fr)); }

.w-full { width: 100%; }
.h-full { height: 100%; }
.relative { position: relative; }
.overflow-hidden { overflow: hidden; }
.text-center { text-align: center; }
.font-bold { font-weight: 700; }
.font-semibold { font-weight: 600; }

.mt-sm { margin-top: var(--space-sm); }
.mt-md { margin-top: var(--space-md); }
.mt-lg { margin-top: var(--space-lg); }
.mt-xl { margin-top: var(--space-xl); }
.mb-sm { margin-bottom: var(--space-sm); }
.mb-md { margin-bottom: var(--space-md); }
.mb-lg { margin-bottom: var(--space-lg); }

.p-md { padding: var(--space-md); }
.p-lg { padding: var(--space-lg); }
.p-xl { padding: var(--space-xl); }

/* ---------- Responsive ---------- */
@media (max-width: 1024px) {
  .grid-4 { grid-template-columns: repeat(2, 1fr); }
  .grid-3 { grid-template-columns: repeat(2, 1fr); }
}

@media (max-width: 768px) {
  :root {
    --sidebar-width: 0px;
    --topbar-height: 56px;
  }

  .grid-4, .grid-3, .grid-2 {
    grid-template-columns: 1fr;
  }

  .heading-1 { font-size: var(--text-3xl); }
  .heading-2 { font-size: var(--text-2xl); }
}

/* ---------- Word Lab Editor Toolbar ---------- */
.editor-btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  min-width: 30px;
  height: 28px;
  padding: 0 6px;
  background: var(--bg-glass);
  border: 1px solid var(--border-subtle);
  border-radius: 4px;
  color: var(--text-primary);
  font-size: 0.75rem;
  font-weight: 600;
  cursor: pointer;
  transition: all var(--transition-fast);
}

.editor-btn:hover {
  background: var(--bg-glass-active);
  border-color: var(--primary-500);
  color: var(--primary-300);
}

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