/* ============================================================
   IQGAME - Intelligence Entertainment & Brain Training Platform
   Main Stylesheet
   Version: 1.0.0
   Target Audience: Ages 12-35 | Modern, Vibrant, Engaging
   ============================================================ */

/* ────────────────────────────────────────────────────────────
   1. CSS CUSTOM PROPERTIES (THEMING)
   ──────────────────────────────────────────────────────────── */
:root {
  /* ── Brand Colors ── */
  --color-primary: #6C5CE7;
  --color-primary-light: #A29BFE;
  --color-primary-dark: #5341D0;
  --color-secondary: #00CEC9;
  --color-secondary-light: #55EFC4;
  --color-secondary-dark: #00B5B0;
  --color-accent: #FD79A8;
  --color-accent-light: #FDCB6E;
  --color-accent-dark: #E84393;
  --color-dark: #2D3436;
  --color-dark-light: #636E72;
  --color-dark-lighter: #B2BEC3;

  /* ── Neutral Colors ── */
  --color-white: #FFFFFF;
  --color-off-white: #F8F9FA;
  --color-gray-50: #F1F2F6;
  --color-gray-100: #DFE4EA;
  --color-gray-200: #CED6E0;
  --color-gray-300: #A4B0BE;
  --color-gray-400: #747D8C;
  --color-gray-500: #57606F;
  --color-gray-600: #2F3542;
  --color-gray-700: #1E272E;
  --color-gray-800: #181F25;
  --color-gray-900: #0D1117;

  /* ── Semantic Colors ── */
  --color-success: #00B894;
  --color-success-light: #55EFC4;
  --color-warning: #FDCB6E;
  --color-warning-dark: #F0932B;
  --color-error: #FF6B6B;
  --color-error-dark: #EE5A24;
  --color-info: #74B9FF;
  --color-info-dark: #0984E3;

  /* ── Gradients ── */
  --gradient-primary: linear-gradient(135deg, #6C5CE7 0%, #A29BFE 100%);
  --gradient-secondary: linear-gradient(135deg, #00CEC9 0%, #55EFC4 100%);
  --gradient-accent: linear-gradient(135deg, #FD79A8 0%, #FDCB6E 100%);
  --gradient-hero: linear-gradient(135deg, #6C5CE7 0%, #00CEC9 50%, #FD79A8 100%);
  --gradient-dark: linear-gradient(135deg, #2D3436 0%, #636E72 100%);
  --gradient-glass: linear-gradient(135deg, rgba(255,255,255,0.25) 0%, rgba(255,255,255,0.05) 100%);
  --gradient-warm: linear-gradient(135deg, #FDCB6E 0%, #FD79A8 100%);
  --gradient-cool: linear-gradient(135deg, #74B9FF 0%, #6C5CE7 100%);

  /* ── Typography ── */
  --font-primary: 'Inter', 'Segoe UI', system-ui, -apple-system, sans-serif;
  --font-heading: 'Poppins', 'Inter', system-ui, sans-serif;
  --font-mono: 'JetBrains Mono', 'Fira Code', 'Consolas', monospace;

  /* ── Font Sizes (fluid) ── */
  --fs-xs: clamp(0.7rem, 0.66rem + 0.2vw, 0.8rem);
  --fs-sm: clamp(0.8rem, 0.74rem + 0.3vw, 0.9rem);
  --fs-base: clamp(0.9rem, 0.84rem + 0.3vw, 1rem);
  --fs-md: clamp(1rem, 0.92rem + 0.4vw, 1.15rem);
  --fs-lg: clamp(1.15rem, 1.04rem + 0.55vw, 1.35rem);
  --fs-xl: clamp(1.35rem, 1.18rem + 0.85vw, 1.75rem);
  --fs-2xl: clamp(1.75rem, 1.48rem + 1.35vw, 2.5rem);
  --fs-3xl: clamp(2.25rem, 1.8rem + 2.25vw, 3.5rem);
  --fs-4xl: clamp(2.75rem, 2.1rem + 3.25vw, 4.5rem);

  /* ── Spacing ── */
  --space-xs: 0.25rem;
  --space-sm: 0.5rem;
  --space-md: 1rem;
  --space-lg: 1.5rem;
  --space-xl: 2rem;
  --space-2xl: 3rem;
  --space-3xl: 4rem;
  --space-4xl: 6rem;

  /* ── Border Radius ── */
  --radius-sm: 6px;
  --radius-md: 10px;
  --radius-lg: 16px;
  --radius-xl: 24px;
  --radius-full: 9999px;

  /* ── Shadows ── */
  --shadow-sm: 0 1px 3px rgba(0,0,0,0.08), 0 1px 2px rgba(0,0,0,0.06);
  --shadow-md: 0 4px 6px rgba(0,0,0,0.07), 0 2px 4px rgba(0,0,0,0.06);
  --shadow-lg: 0 10px 25px rgba(0,0,0,0.1), 0 6px 10px rgba(0,0,0,0.08);
  --shadow-xl: 0 20px 50px rgba(0,0,0,0.15), 0 12px 20px rgba(0,0,0,0.1);
  --shadow-glow-primary: 0 0 20px rgba(108,92,231,0.4);
  --shadow-glow-secondary: 0 0 20px rgba(0,206,201,0.4);
  --shadow-glow-accent: 0 0 20px rgba(253,121,168,0.4);

  /* ── Z-Index Scale ── */
  --z-base: 1;
  --z-dropdown: 100;
  --z-sticky: 200;
  --z-overlay: 300;
  --z-modal: 400;
  --z-toast: 500;
  --z-tooltip: 600;

  /* ── Transitions ── */
  --transition-fast: 150ms ease;
  --transition-base: 250ms ease;
  --transition-slow: 400ms ease;
  --transition-bounce: 400ms cubic-bezier(0.68, -0.55, 0.265, 1.55);

  /* ── Glass-morphism ── */
  --glass-bg: rgba(255, 255, 255, 0.15);
  --glass-border: rgba(255, 255, 255, 0.25);
  --glass-blur: 16px;

  /* ── Container ── */
  --container-max: 1200px;
  --container-padding: clamp(1rem, 3vw, 2rem);
}

/* ────────────────────────────────────────────────────────────
   2. RESET & BASE
   ──────────────────────────────────────────────────────────── */
*,
*::before,
*::after {
  margin: 0;
  padding: 0;
  box-sizing: border-box;
}

html {
  scroll-behavior: smooth;
  -webkit-text-size-adjust: 100%;
  font-size: 16px;
}

body {
  font-family: var(--font-primary);
  font-size: var(--fs-base);
  line-height: 1.6;
  color: var(--color-dark);
  background-color: var(--color-off-white);
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
  overflow-x: hidden;
}

img,
picture,
video,
canvas,
svg {
  display: block;
  max-width: 100%;
}

input,
button,
textarea,
select {
  font: inherit;
  color: inherit;
}

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

a:hover {
  color: var(--color-primary-dark);
}

ul,
ol {
  list-style: none;
}

h1, h2, h3, h4, h5, h6 {
  font-family: var(--font-heading);
  font-weight: 700;
  line-height: 1.2;
  color: var(--color-dark);
}

h1 { font-size: var(--fs-4xl); }
h2 { font-size: var(--fs-3xl); }
h3 { font-size: var(--fs-2xl); }
h4 { font-size: var(--fs-xl); }
h5 { font-size: var(--fs-lg); }
h6 { font-size: var(--fs-md); }

p {
  margin-bottom: var(--space-md);
  color: var(--color-dark-light);
}

/* ────────────────────────────────────────────────────────────
   3. ACCESSIBILITY
   ──────────────────────────────────────────────────────────── */
:focus-visible {
  outline: 3px solid var(--color-primary);
  outline-offset: 3px;
  border-radius: var(--radius-sm);
}

.sr-only {
  position: absolute;
  width: 1px;
  height: 1px;
  padding: 0;
  margin: -1px;
  overflow: hidden;
  clip: rect(0, 0, 0, 0);
  white-space: nowrap;
  border: 0;
}

.skip-link {
  position: absolute;
  top: -100%;
  left: var(--space-md);
  padding: var(--space-sm) var(--space-md);
  background: var(--color-primary);
  color: var(--color-white);
  border-radius: var(--radius-sm);
  z-index: var(--z-tooltip);
  transition: top var(--transition-fast);
}

.skip-link:focus {
  top: var(--space-md);
}

/* Reduced motion preference */
@media (prefers-reduced-motion: reduce) {
  *,
  *::before,
  *::after {
    animation-duration: 0.01ms !important;
    animation-iteration-count: 1 !important;
    transition-duration: 0.01ms !important;
    scroll-behavior: auto !important;
  }
}

/* ────────────────────────────────────────────────────────────
   4. UTILITY CLASSES
   ──────────────────────────────────────────────────────────── */
.container {
  width: 100%;
  max-width: var(--container-max);
  margin-inline: auto;
  padding-inline: var(--container-padding);
}

.flex {
  display: flex;
}

.flex-center {
  display: flex;
  align-items: center;
  justify-content: center;
}

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

.flex-col {
  flex-direction: column;
}

.grid {
  display: grid;
}

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

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

.text-gradient-primary {
  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;
}

.visually-hidden {
  position: absolute;
  width: 1px;
  height: 1px;
  overflow: hidden;
  clip: rect(0 0 0 0);
}

/* ────────────────────────────────────────────────────────────
   5. ANIMATIONS & KEYFRAMES
   ──────────────────────────────────────────────────────────── */
@keyframes float {
  0%, 100% { transform: translateY(0px) rotate(0deg); }
  25% { transform: translateY(-12px) rotate(2deg); }
  50% { transform: translateY(-20px) rotate(0deg); }
  75% { transform: translateY(-12px) rotate(-2deg); }
}

@keyframes float-slow {
  0%, 100% { transform: translateY(0px); }
  50% { transform: translateY(-30px); }
}

@keyframes float-reverse {
  0%, 100% { transform: translateY(-20px); }
  50% { transform: translateY(0px); }
}

@keyframes pulse {
  0%, 100% { transform: scale(1); opacity: 1; }
  50% { transform: scale(1.05); opacity: 0.9; }
}

@keyframes pulse-glow {
  0%, 100% {
    box-shadow: 0 0 5px rgba(108,92,231,0.4);
    transform: scale(1);
  }
  50% {
    box-shadow: 0 0 25px rgba(108,92,231,0.6), 0 0 50px rgba(108,92,231,0.3);
    transform: scale(1.02);
  }
}

@keyframes slide-in-right {
  from {
    opacity: 0;
    transform: translateX(60px);
  }
  to {
    opacity: 1;
    transform: translateX(0);
  }
}

@keyframes slide-in-left {
  from {
    opacity: 0;
    transform: translateX(-60px);
  }
  to {
    opacity: 1;
    transform: translateX(0);
  }
}

@keyframes slide-in-up {
  from {
    opacity: 0;
    transform: translateY(40px);
  }
  to {
    opacity: 1;
    transform: translateY(0);
  }
}

@keyframes slide-in-down {
  from {
    opacity: 0;
    transform: translateY(-40px);
  }
  to {
    opacity: 1;
    transform: translateY(0);
  }
}

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

@keyframes scale-in {
  from {
    opacity: 0;
    transform: scale(0.85);
  }
  to {
    opacity: 1;
    transform: scale(1);
  }
}

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

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

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

@keyframes confetti-sway {
  0%, 100% { transform: translateX(0); }
  25% { transform: translateX(20px); }
  75% { transform: translateX(-20px); }
}

@keyframes brain-pulse {
  0%, 100% {
    filter: drop-shadow(0 0 8px rgba(108,92,231,0.4));
    transform: scale(1);
  }
  50% {
    filter: drop-shadow(0 0 20px rgba(108,92,231,0.7));
    transform: scale(1.05);
  }
}

@keyframes progress-fill {
  from { width: 0%; }
}

@keyframes bounce-in {
  0% { transform: scale(0); opacity: 0; }
  50% { transform: scale(1.1); }
  70% { transform: scale(0.95); }
  100% { transform: scale(1); opacity: 1; }
}

@keyframes shake {
  0%, 100% { transform: translateX(0); }
  10%, 30%, 50%, 70%, 90% { transform: translateX(-4px); }
  20%, 40%, 60%, 80% { transform: translateX(4px); }
}

@keyframes typewriter {
  from { width: 0; }
  to { width: 100%; }
}

@keyframes ripple {
  0% {
    transform: scale(0);
    opacity: 0.5;
  }
  100% {
    transform: scale(4);
    opacity: 0;
  }
}

/* Animation utility classes */
.animate-float { animation: float 6s ease-in-out infinite; }
.animate-float-slow { animation: float-slow 8s ease-in-out infinite; }
.animate-float-reverse { animation: float-reverse 7s ease-in-out infinite; }
.animate-pulse { animation: pulse 2s ease-in-out infinite; }
.animate-pulse-glow { animation: pulse-glow 2s ease-in-out infinite; }
.animate-slide-in-right { animation: slide-in-right 0.5s ease-out forwards; }
.animate-slide-in-left { animation: slide-in-left 0.5s ease-out forwards; }
.animate-slide-in-up { animation: slide-in-up 0.5s ease-out forwards; }
.animate-fade-in { animation: fade-in 0.4s ease-out forwards; }
.animate-scale-in { animation: scale-in 0.3s ease-out forwards; }
.animate-bounce-in { animation: bounce-in 0.6s ease-out forwards; }
.animate-shake { animation: shake 0.5s ease-in-out; }

/* Staggered animation delays */
.stagger-1 { animation-delay: 0.1s; }
.stagger-2 { animation-delay: 0.2s; }
.stagger-3 { animation-delay: 0.3s; }
.stagger-4 { animation-delay: 0.4s; }
.stagger-5 { animation-delay: 0.5s; }
.stagger-6 { animation-delay: 0.6s; }

/* ────────────────────────────────────────────────────────────
   6. NAVIGATION BAR
   ──────────────────────────────────────────────────────────── */
.navbar {
  position: sticky;
  top: 0;
  z-index: var(--z-sticky);
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: var(--space-sm) var(--space-lg);
  background: var(--glass-bg);
  backdrop-filter: blur(var(--glass-blur));
  -webkit-backdrop-filter: blur(var(--glass-blur));
  border-bottom: 1px solid var(--glass-border);
  transition: all var(--transition-base);
}

.navbar.scrolled {
  padding-block: var(--space-xs);
  background: rgba(255, 255, 255, 0.92);
  box-shadow: var(--shadow-md);
}

.navbar__logo {
  display: flex;
  align-items: center;
  gap: var(--space-sm);
  font-family: var(--font-heading);
  font-size: var(--fs-xl);
  font-weight: 800;
  color: var(--color-dark);
  text-decoration: none;
}

.navbar__logo-icon {
  width: 40px;
  height: 40px;
  background: var(--gradient-primary);
  border-radius: var(--radius-md);
  display: flex;
  align-items: center;
  justify-content: center;
  color: var(--color-white);
  font-size: 1.2rem;
  animation: brain-pulse 3s ease-in-out infinite;
}

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

.navbar__menu {
  display: flex;
  align-items: center;
  gap: var(--space-lg);
}

.navbar__link {
  position: relative;
  font-weight: 500;
  font-size: var(--fs-sm);
  color: var(--color-dark-light);
  padding: var(--space-xs) 0;
  transition: color var(--transition-fast);
}

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

.navbar__link:hover,
.navbar__link.active {
  color: var(--color-primary);
}

.navbar__link:hover::after,
.navbar__link.active::after {
  width: 100%;
}

.navbar__actions {
  display: flex;
  align-items: center;
  gap: var(--space-sm);
}

.navbar__avatar {
  width: 36px;
  height: 36px;
  border-radius: var(--radius-full);
  border: 2px solid var(--color-primary);
  object-fit: cover;
  cursor: pointer;
  transition: transform var(--transition-fast), box-shadow var(--transition-fast);
}

.navbar__avatar:hover {
  transform: scale(1.1);
  box-shadow: var(--shadow-glow-primary);
}

/* Hamburger Menu */
.navbar__hamburger {
  display: none;
  flex-direction: column;
  justify-content: center;
  gap: 5px;
  width: 30px;
  height: 30px;
  background: none;
  border: none;
  cursor: pointer;
  padding: 0;
  z-index: calc(var(--z-modal) + 1);
}

.navbar__hamburger span {
  display: block;
  width: 100%;
  height: 2.5px;
  background: var(--color-dark);
  border-radius: var(--radius-full);
  transition: all var(--transition-base);
  transform-origin: center;
}

.navbar__hamburger.active span:nth-child(1) {
  transform: rotate(45deg) translate(5px, 5px);
}

.navbar__hamburger.active span:nth-child(2) {
  opacity: 0;
  transform: scaleX(0);
}

.navbar__hamburger.active span:nth-child(3) {
  transform: rotate(-45deg) translate(5px, -5px);
}

/* Mobile Navigation Overlay */
.navbar__mobile-menu {
  display: none;
  position: fixed;
  inset: 0;
  background: rgba(45, 52, 54, 0.95);
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
  z-index: var(--z-modal);
  flex-direction: column;
  align-items: center;
  justify-content: center;
  gap: var(--space-xl);
  animation: fade-in 0.3s ease-out;
}

.navbar__mobile-menu.open {
  display: flex;
}

.navbar__mobile-menu .navbar__link {
  font-size: var(--fs-xl);
  color: var(--color-white);
  padding: var(--space-sm) var(--space-lg);
}

.navbar__mobile-menu .navbar__link::after {
  background: var(--gradient-accent);
}

@media (max-width: 768px) {
  .navbar__menu,
  .navbar__actions {
    display: none;
  }

  .navbar__hamburger {
    display: flex;
  }
}

/* ────────────────────────────────────────────────────────────
   7. HERO SECTION
   ──────────────────────────────────────────────────────────── */
.hero {
  position: relative;
  min-height: 90vh;
  display: flex;
  align-items: center;
  justify-content: center;
  overflow: hidden;
  padding: var(--space-4xl) var(--container-padding);
  background: var(--gradient-hero);
  background-size: 200% 200%;
  animation: gradient-shift 8s ease infinite;
}

@keyframes gradient-shift {
  0% { background-position: 0% 50%; }
  50% { background-position: 100% 50%; }
  100% { background-position: 0% 50%; }
}

.hero__content {
  position: relative;
  z-index: 2;
  text-align: center;
  max-width: 700px;
  animation: slide-in-up 0.8s ease-out;
}

.hero__title {
  font-size: var(--fs-4xl);
  color: var(--color-white);
  margin-bottom: var(--space-md);
  text-shadow: 0 2px 10px rgba(0,0,0,0.15);
}

.hero__title .highlight {
  position: relative;
  display: inline-block;
}

.hero__title .highlight::after {
  content: '';
  position: absolute;
  bottom: 5px;
  left: 0;
  width: 100%;
  height: 12px;
  background: rgba(253, 121, 168, 0.4);
  border-radius: var(--radius-sm);
  z-index: -1;
  transform: rotate(-1deg);
}

.hero__subtitle {
  font-size: var(--fs-lg);
  color: rgba(255,255,255,0.9);
  margin-bottom: var(--space-xl);
  font-weight: 400;
  line-height: 1.7;
}

.hero__cta-group {
  display: flex;
  gap: var(--space-md);
  justify-content: center;
  flex-wrap: wrap;
}

/* Floating brain icons */
.hero__floating-elements {
  position: absolute;
  inset: 0;
  pointer-events: none;
  overflow: hidden;
}

.hero__float-icon {
  position: absolute;
  font-size: 3rem;
  opacity: 0.15;
  color: var(--color-white);
  animation: float 6s ease-in-out infinite;
}

.hero__float-icon:nth-child(1) { top: 10%; left: 8%; animation-delay: 0s; font-size: 4rem; }
.hero__float-icon:nth-child(2) { top: 60%; left: 5%; animation-delay: 1s; animation-duration: 8s; }
.hero__float-icon:nth-child(3) { top: 20%; right: 10%; animation-delay: 2s; font-size: 3.5rem; }
.hero__float-icon:nth-child(4) { bottom: 15%; right: 8%; animation-delay: 0.5s; animation-duration: 7s; }
.hero__float-icon:nth-child(5) { top: 45%; left: 15%; animation-delay: 3s; font-size: 2.5rem; }
.hero__float-icon:nth-child(6) { bottom: 30%; right: 20%; animation-delay: 1.5s; font-size: 3rem; }

/* Hero background circles */
.hero__bg-circle {
  position: absolute;
  border-radius: var(--radius-full);
  border: 2px solid rgba(255,255,255,0.1);
  animation: float-slow 10s ease-in-out infinite;
}

.hero__bg-circle:nth-child(1) {
  width: 300px; height: 300px;
  top: -50px; right: -80px;
}

.hero__bg-circle:nth-child(2) {
  width: 200px; height: 200px;
  bottom: -40px; left: -60px;
  animation-delay: 2s;
}

.hero__stats {
  display: flex;
  gap: var(--space-xl);
  justify-content: center;
  margin-top: var(--space-2xl);
}

.hero__stat {
  text-align: center;
  color: var(--color-white);
}

.hero__stat-number {
  display: block;
  font-size: var(--fs-2xl);
  font-weight: 800;
  font-family: var(--font-heading);
}

.hero__stat-label {
  font-size: var(--fs-xs);
  opacity: 0.8;
  text-transform: uppercase;
  letter-spacing: 1px;
}

@media (max-width: 768px) {
  .hero {
    min-height: 80vh;
    padding: var(--space-3xl) var(--container-padding);
  }
  .hero__stats {
    gap: var(--space-md);
  }
  .hero__stat-number {
    font-size: var(--fs-xl);
  }
}

/* ────────────────────────────────────────────────────────────
   8. BUTTONS
   ──────────────────────────────────────────────────────────── */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: var(--space-sm);
  padding: 0.7rem 1.5rem;
  font-family: var(--font-primary);
  font-weight: 600;
  font-size: var(--fs-sm);
  line-height: 1.4;
  border: 2px solid transparent;
  border-radius: var(--radius-md);
  cursor: pointer;
  transition: all var(--transition-base);
  text-decoration: none;
  white-space: nowrap;
  position: relative;
  overflow: hidden;
}

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

/* Primary Button */
.btn--primary {
  background: var(--gradient-primary);
  color: var(--color-white);
  box-shadow: 0 4px 15px rgba(108,92,231,0.35);
}

.btn--primary:hover {
  box-shadow: 0 6px 25px rgba(108,92,231,0.5);
  transform: translateY(-2px);
}

/* Secondary Button */
.btn--secondary {
  background: var(--gradient-secondary);
  color: var(--color-white);
  box-shadow: 0 4px 15px rgba(0,206,201,0.35);
}

.btn--secondary:hover {
  box-shadow: 0 6px 25px rgba(0,206,201,0.5);
  transform: translateY(-2px);
}

/* Accent Button */
.btn--accent {
  background: var(--gradient-accent);
  color: var(--color-white);
  box-shadow: 0 4px 15px rgba(253,121,168,0.35);
}

.btn--accent:hover {
  box-shadow: 0 6px 25px rgba(253,121,168,0.5);
  transform: translateY(-2px);
}

/* Outline Buttons */
.btn--outline {
  background: transparent;
  border-color: var(--color-primary);
  color: var(--color-primary);
}

.btn--outline:hover {
  background: var(--color-primary);
  color: var(--color-white);
}

.btn--outline-white {
  background: transparent;
  border-color: var(--color-white);
  color: var(--color-white);
}

.btn--outline-white:hover {
  background: var(--color-white);
  color: var(--color-primary);
}

/* Ghost Button */
.btn--ghost {
  background: transparent;
  color: var(--color-primary);
  border-color: transparent;
}

.btn--ghost:hover {
  background: rgba(108,92,231,0.08);
}

/* Danger Button */
.btn--danger {
  background: var(--color-error);
  color: var(--color-white);
}

.btn--danger:hover {
  background: var(--color-error-dark);
  transform: translateY(-2px);
}

/* Success Button */
.btn--success {
  background: var(--color-success);
  color: var(--color-white);
}

.btn--success:hover {
  background: #009B7D;
  transform: translateY(-2px);
}

/* Button Sizes */
.btn--sm {
  padding: 0.4rem 1rem;
  font-size: var(--fs-xs);
  border-radius: var(--radius-sm);
}

.btn--lg {
  padding: 1rem 2.25rem;
  font-size: var(--fs-md);
  border-radius: var(--radius-lg);
}

.btn--xl {
  padding: 1.2rem 3rem;
  font-size: var(--fs-lg);
  border-radius: var(--radius-lg);
}

/* CTA pulse effect */
.btn--cta {
  animation: pulse-glow 2s ease-in-out infinite;
}

.btn--cta:hover {
  animation: none;
  transform: translateY(-3px);
  box-shadow: 0 8px 30px rgba(108,92,231,0.5);
}

/* Button with icon */
.btn__icon {
  width: 1.1em;
  height: 1.1em;
  flex-shrink: 0;
}

/* Button group */
.btn-group {
  display: flex;
  flex-wrap: wrap;
  gap: var(--space-sm);
}

/* Ripple effect base */
.btn .ripple {
  position: absolute;
  border-radius: var(--radius-full);
  background: rgba(255,255,255,0.4);
  animation: ripple 0.6s ease-out;
  pointer-events: none;
}

/* Icon-only button */
.btn--icon {
  width: 40px;
  height: 40px;
  padding: 0;
  border-radius: var(--radius-full);
}

.btn--icon.btn--sm {
  width: 32px;
  height: 32px;
}

.btn--icon.btn--lg {
  width: 48px;
  height: 48px;
}

/* ────────────────────────────────────────────────────────────
   9. CARD COMPONENTS
   ──────────────────────────────────────────────────────────── */
.card {
  background: var(--color-white);
  border-radius: var(--radius-lg);
  overflow: hidden;
  box-shadow: var(--shadow-sm);
  transition: all var(--transition-base);
  border: 1px solid var(--color-gray-100);
}

.card:hover {
  transform: translateY(-6px);
  box-shadow: var(--shadow-lg);
}

.card__image {
  width: 100%;
  height: 200px;
  object-fit: cover;
  transition: transform var(--transition-slow);
}

.card:hover .card__image {
  transform: scale(1.05);
}

.card__image-wrapper {
  position: relative;
  overflow: hidden;
}

.card__badge {
  position: absolute;
  top: var(--space-md);
  left: var(--space-md);
  padding: var(--space-xs) var(--space-sm);
  font-size: var(--fs-xs);
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 0.5px;
  border-radius: var(--radius-sm);
  color: var(--color-white);
  z-index: 2;
}

.card__badge--primary { background: var(--color-primary); }
.card__badge--secondary { background: var(--color-secondary); }
.card__badge--accent { background: var(--color-accent); }
.card__badge--new { background: var(--color-error); }

.card__body {
  padding: var(--space-lg);
}

.card__title {
  font-size: var(--fs-lg);
  font-weight: 700;
  margin-bottom: var(--space-sm);
  color: var(--color-dark);
}

.card__text {
  font-size: var(--fs-sm);
  color: var(--color-dark-light);
  margin-bottom: var(--space-md);
  line-height: 1.6;
}

.card__footer {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: var(--space-md) var(--space-lg);
  border-top: 1px solid var(--color-gray-100);
}

.card__meta {
  display: flex;
  align-items: center;
  gap: var(--space-sm);
  font-size: var(--fs-xs);
  color: var(--color-dark-lighter);
}

/* Glass Card */
.card--glass {
  background: var(--glass-bg);
  backdrop-filter: blur(var(--glass-blur));
  -webkit-backdrop-filter: blur(var(--glass-blur));
  border: 1px solid var(--glass-border);
  color: var(--color-white);
}

.card--glass .card__title {
  color: var(--color-white);
}

.card--glass .card__text {
  color: rgba(255,255,255,0.8);
}

/* Gradient Cards */
.card--gradient-primary {
  background: var(--gradient-primary);
  color: var(--color-white);
}

.card--gradient-secondary {
  background: var(--gradient-secondary);
  color: var(--color-white);
}

.card--gradient-accent {
  background: var(--gradient-accent);
  color: var(--color-white);
}

.card--gradient-primary .card__title,
.card--gradient-secondary .card__title,
.card--gradient-accent .card__title {
  color: var(--color-white);
}

.card--gradient-primary .card__text,
.card--gradient-secondary .card__text,
.card--gradient-accent .card__text {
  color: rgba(255,255,255,0.85);
}

/* Card Grid */
.card-grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: var(--space-xl);
}

@media (min-width: 768px) {
  .card-grid {
    grid-template-columns: repeat(2, 1fr);
  }
}

@media (min-width: 1024px) {
  .card-grid {
    grid-template-columns: repeat(3, 1fr);
  }
}

.card-grid--4-col {
  grid-template-columns: 1fr;
}

@media (min-width: 768px) {
  .card-grid--4-col {
    grid-template-columns: repeat(2, 1fr);
  }
}

@media (min-width: 1024px) {
  .card-grid--4-col {
    grid-template-columns: repeat(4, 1fr);
  }
}

/* ────────────────────────────────────────────────────────────
   10. QUIZ / TEST UI
   ──────────────────────────────────────────────────────────── */
.quiz-container {
  max-width: 800px;
  margin: 0 auto;
  padding: var(--space-xl) var(--container-padding);
}

.quiz-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  margin-bottom: var(--space-xl);
  flex-wrap: wrap;
  gap: var(--space-md);
}

.quiz-progress {
  flex: 1;
  min-width: 200px;
}

.quiz-progress__bar {
  width: 100%;
  height: 8px;
  background: var(--color-gray-100);
  border-radius: var(--radius-full);
  overflow: hidden;
  position: relative;
}

.quiz-progress__fill {
  height: 100%;
  background: var(--gradient-primary);
  border-radius: var(--radius-full);
  transition: width 0.5s cubic-bezier(0.4, 0, 0.2, 1);
  animation: progress-fill 1s ease-out;
  position: relative;
}

.quiz-progress__fill::after {
  content: '';
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  bottom: 0;
  background: linear-gradient(
    90deg,
    transparent,
    rgba(255,255,255,0.3),
    transparent
  );
  background-size: 200% 100%;
  animation: shimmer 2s infinite;
}

.quiz-progress__text {
  display: flex;
  justify-content: space-between;
  margin-top: var(--space-xs);
  font-size: var(--fs-xs);
  color: var(--color-dark-lighter);
}

/* Timer */
.quiz-timer {
  display: flex;
  align-items: center;
  gap: var(--space-sm);
  padding: var(--space-sm) var(--space-md);
  background: var(--color-gray-50);
  border-radius: var(--radius-md);
  font-weight: 600;
  font-size: var(--fs-md);
  font-family: var(--font-mono);
}

.quiz-timer--warning {
  background: rgba(253,203,110,0.2);
  color: var(--color-warning-dark);
}

.quiz-timer--danger {
  background: rgba(255,107,107,0.2);
  color: var(--color-error);
  animation: pulse 1s ease-in-out infinite;
}

.quiz-timer__icon {
  font-size: 1.2em;
}

/* Question Card */
.quiz-question {
  background: var(--color-white);
  border-radius: var(--radius-lg);
  padding: var(--space-2xl);
  box-shadow: var(--shadow-md);
  margin-bottom: var(--space-xl);
  animation: slide-in-right 0.4s ease-out;
}

.quiz-question__number {
  display: inline-block;
  padding: var(--space-xs) var(--space-md);
  background: var(--gradient-primary);
  color: var(--color-white);
  border-radius: var(--radius-full);
  font-size: var(--fs-xs);
  font-weight: 700;
  margin-bottom: var(--space-md);
}

.quiz-question__text {
  font-size: var(--fs-lg);
  font-weight: 600;
  color: var(--color-dark);
  margin-bottom: var(--space-xl);
  line-height: 1.5;
}

/* Option Buttons */
.quiz-options {
  display: flex;
  flex-direction: column;
  gap: var(--space-md);
}

.quiz-option {
  display: flex;
  align-items: center;
  gap: var(--space-md);
  padding: var(--space-md) var(--space-lg);
  background: var(--color-gray-50);
  border: 2px solid var(--color-gray-100);
  border-radius: var(--radius-md);
  cursor: pointer;
  transition: all var(--transition-base);
  font-size: var(--fs-base);
  text-align: left;
  width: 100%;
}

.quiz-option:hover {
  border-color: var(--color-primary);
  background: rgba(108,92,231,0.05);
  transform: translateX(4px);
}

.quiz-option.selected {
  border-color: var(--color-primary);
  background: rgba(108,92,231,0.1);
  box-shadow: var(--shadow-glow-primary);
}

.quiz-option.correct {
  border-color: var(--color-success);
  background: rgba(0,184,148,0.1);
}

.quiz-option.incorrect {
  border-color: var(--color-error);
  background: rgba(255,107,107,0.1);
  animation: shake 0.5s ease-in-out;
}

.quiz-option__letter {
  width: 32px;
  height: 32px;
  display: flex;
  align-items: center;
  justify-content: center;
  background: var(--color-white);
  border-radius: var(--radius-full);
  font-weight: 700;
  font-size: var(--fs-sm);
  color: var(--color-primary);
  flex-shrink: 0;
  border: 2px solid var(--color-gray-200);
  transition: all var(--transition-base);
}

.quiz-option:hover .quiz-option__letter,
.quiz-option.selected .quiz-option__letter {
  background: var(--color-primary);
  color: var(--color-white);
  border-color: var(--color-primary);
}

.quiz-option.correct .quiz-option__letter {
  background: var(--color-success);
  color: var(--color-white);
  border-color: var(--color-success);
}

.quiz-option.incorrect .quiz-option__letter {
  background: var(--color-error);
  color: var(--color-white);
  border-color: var(--color-error);
}

.quiz-option__text {
  flex: 1;
}

.quiz-option__feedback {
  font-size: 1.2rem;
  flex-shrink: 0;
}

/* Quiz Navigation */
.quiz-nav {
  display: flex;
  justify-content: space-between;
  align-items: center;
  gap: var(--space-md);
  margin-top: var(--space-xl);
}

/* ────────────────────────────────────────────────────────────
   11. RADAR CHART CONTAINER (RESULTS)
   ──────────────────────────────────────────────────────────── */
.results-section {
  padding: var(--space-3xl) 0;
}

.radar-chart-container {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: var(--space-xl);
  padding: var(--space-xl);
  background: var(--color-white);
  border-radius: var(--radius-lg);
  box-shadow: var(--shadow-md);
}

.radar-chart-container__svg {
  width: 100%;
  max-width: 450px;
  aspect-ratio: 1;
}

.radar-chart-container__title {
  font-size: var(--fs-xl);
  text-align: center;
}

.radar-chart-container__subtitle {
  text-align: center;
  color: var(--color-dark-lighter);
  font-size: var(--fs-sm);
}

/* Score display */
.score-display {
  text-align: center;
  margin-bottom: var(--space-xl);
}

.score-display__value {
  font-size: var(--fs-4xl);
  font-weight: 800;
  font-family: var(--font-heading);
  background: var(--gradient-primary);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
  line-height: 1;
}

.score-display__label {
  font-size: var(--fs-sm);
  color: var(--color-dark-lighter);
  text-transform: uppercase;
  letter-spacing: 2px;
  margin-top: var(--space-xs);
}

/* Score breakdown list */
.score-breakdown {
  width: 100%;
  max-width: 500px;
}

.score-breakdown__item {
  display: flex;
  align-items: center;
  gap: var(--space-md);
  padding: var(--space-sm) 0;
  border-bottom: 1px solid var(--color-gray-100);
}

.score-breakdown__item:last-child {
  border-bottom: none;
}

.score-breakdown__label {
  flex: 1;
  font-weight: 500;
  font-size: var(--fs-sm);
}

.score-breakdown__bar {
  width: 120px;
  height: 6px;
  background: var(--color-gray-100);
  border-radius: var(--radius-full);
  overflow: hidden;
}

.score-breakdown__bar-fill {
  height: 100%;
  border-radius: var(--radius-full);
  transition: width 1s ease-out;
}

.score-breakdown__value {
  font-weight: 700;
  font-size: var(--fs-sm);
  min-width: 35px;
  text-align: right;
}

/* ────────────────────────────────────────────────────────────
   12. GAME BOARD STYLES
   ──────────────────────────────────────────────────────────── */
.game-board {
  display: inline-grid;
  gap: 2px;
  background: var(--color-gray-300);
  border: 3px solid var(--color-gray-400);
  border-radius: var(--radius-md);
  padding: 2px;
  box-shadow: var(--shadow-md);
}

.game-board--sudoku {
  grid-template-columns: repeat(9, 1fr);
  grid-template-rows: repeat(9, 1fr);
  gap: 1px;
  max-width: 450px;
  width: 100%;
}

.game-board--minesweeper {
  gap: 1px;
  max-width: 500px;
  width: 100%;
}

.game-board--memory {
  gap: var(--space-sm);
  max-width: 600px;
  width: 100%;
}

.game-cell {
  display: flex;
  align-items: center;
  justify-content: center;
  aspect-ratio: 1;
  background: var(--color-white);
  font-weight: 700;
  font-size: var(--fs-md);
  cursor: pointer;
  transition: all var(--transition-fast);
  user-select: none;
  border: none;
  min-width: 0;
}

.game-cell:hover {
  background: var(--color-gray-50);
}

.game-cell:active {
  transform: scale(0.95);
}

/* Sudoku */
.game-cell--sudoku {
  font-family: var(--font-mono);
  font-size: clamp(0.9rem, 3vw, 1.3rem);
}

.game-cell--sudoku.given {
  color: var(--color-dark);
  font-weight: 800;
  background: var(--color-gray-50);
}

.game-cell--sudoku.user-input {
  color: var(--color-primary);
}

.game-cell--sudoku.selected {
  background: rgba(108,92,231,0.15);
  box-shadow: inset 0 0 0 2px var(--color-primary);
}

.game-cell--sudoku.highlighted {
  background: rgba(108,92,231,0.07);
}

.game-cell--sudoku.error {
  color: var(--color-error);
  background: rgba(255,107,107,0.1);
}

/* Sudoku 3x3 block borders */
.game-board--sudoku .game-cell--sudoku:nth-child(3n) {
  border-right: 2px solid var(--color-gray-400);
}

.game-board--sudoku .game-cell--sudoku:nth-child(9n) {
  border-right: none;
}

/* Minesweeper */
.game-cell--mine {
  border-radius: 2px;
  min-width: 28px;
  min-height: 28px;
}

.game-cell--mine.hidden {
  background: var(--color-primary-light);
  box-shadow: inset -2px -2px 3px rgba(0,0,0,0.1), inset 2px 2px 3px rgba(255,255,255,0.3);
}

.game-cell--mine.hidden:hover {
  background: var(--color-primary);
}

.game-cell--mine.revealed {
  background: var(--color-gray-50);
  cursor: default;
}

.game-cell--mine.mine {
  background: var(--color-error);
}

.game-cell--mine.flagged::after {
  content: '🚩';
  font-size: 0.9em;
}

.mine-count-1 { color: #0984E3; }
.mine-count-2 { color: #00B894; }
.mine-count-3 { color: #E17055; }
.mine-count-4 { color: #6C5CE7; }
.mine-count-5 { color: #D63031; }
.mine-count-6 { color: #00CEC9; }
.mine-count-7 { color: #2D3436; }
.mine-count-8 { color: #636E72; }

/* Memory Card Game */
.game-cell--memory {
  border-radius: var(--radius-md);
  perspective: 800px;
  min-height: 80px;
}

.memory-card {
  width: 100%;
  height: 100%;
  position: relative;
  transform-style: preserve-3d;
  transition: transform 0.5s ease;
  cursor: pointer;
}

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

.memory-card__face {
  position: absolute;
  inset: 0;
  display: flex;
  align-items: center;
  justify-content: center;
  backface-visibility: hidden;
  border-radius: var(--radius-md);
  font-size: 2rem;
}

.memory-card__front {
  background: var(--gradient-primary);
  color: var(--color-white);
}

.memory-card__back {
  background: var(--color-white);
  border: 2px solid var(--color-gray-100);
  transform: rotateY(180deg);
}

.memory-card.matched .memory-card__back {
  border-color: var(--color-success);
  background: rgba(0,184,148,0.1);
}

/* Game controls */
.game-controls {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: var(--space-md);
  margin: var(--space-xl) 0;
  flex-wrap: wrap;
}

.game-info {
  display: flex;
  gap: var(--space-xl);
  justify-content: center;
  margin-bottom: var(--space-lg);
  flex-wrap: wrap;
}

.game-info__item {
  display: flex;
  align-items: center;
  gap: var(--space-sm);
  padding: var(--space-sm) var(--space-md);
  background: var(--color-white);
  border-radius: var(--radius-md);
  box-shadow: var(--shadow-sm);
  font-weight: 600;
  font-size: var(--fs-sm);
}

.game-info__icon {
  font-size: 1.2em;
}

/* ────────────────────────────────────────────────────────────
   13. PROFILE & STATS CARDS
   ──────────────────────────────────────────────────────────── */
.profile-card {
  display: flex;
  flex-direction: column;
  align-items: center;
  padding: var(--space-2xl);
  background: var(--color-white);
  border-radius: var(--radius-lg);
  box-shadow: var(--shadow-md);
  text-align: center;
}

.profile-card__avatar {
  width: 100px;
  height: 100px;
  border-radius: var(--radius-full);
  border: 4px solid var(--color-primary);
  object-fit: cover;
  margin-bottom: var(--space-md);
  box-shadow: var(--shadow-glow-primary);
}

.profile-card__name {
  font-size: var(--fs-xl);
  font-weight: 700;
  margin-bottom: var(--space-xs);
}

.profile-card__username {
  font-size: var(--fs-sm);
  color: var(--color-dark-lighter);
  margin-bottom: var(--space-md);
}

.profile-card__level {
  display: inline-block;
  padding: var(--space-xs) var(--space-md);
  background: var(--gradient-primary);
  color: var(--color-white);
  border-radius: var(--radius-full);
  font-size: var(--fs-xs);
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 1px;
  margin-bottom: var(--space-lg);
}

.profile-card__xp-bar {
  width: 100%;
  height: 8px;
  background: var(--color-gray-100);
  border-radius: var(--radius-full);
  overflow: hidden;
  margin-bottom: var(--space-xs);
}

.profile-card__xp-fill {
  height: 100%;
  background: var(--gradient-primary);
  border-radius: var(--radius-full);
  transition: width 1s ease-out;
}

.profile-card__xp-text {
  font-size: var(--fs-xs);
  color: var(--color-dark-lighter);
  margin-bottom: 0;
}

/* Stats Grid */
.stats-grid {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: var(--space-md);
  width: 100%;
  margin-top: var(--space-lg);
}

.stats-grid--3-col {
  grid-template-columns: repeat(3, 1fr);
}

@media (max-width: 768px) {
  .stats-grid--3-col {
    grid-template-columns: repeat(2, 1fr);
  }
}

.stat-card {
  padding: var(--space-md);
  background: var(--color-gray-50);
  border-radius: var(--radius-md);
  text-align: center;
  transition: all var(--transition-base);
}

.stat-card:hover {
  background: var(--color-white);
  box-shadow: var(--shadow-md);
  transform: translateY(-2px);
}

.stat-card__icon {
  font-size: 1.5rem;
  margin-bottom: var(--space-xs);
}

.stat-card__value {
  font-size: var(--fs-xl);
  font-weight: 800;
  font-family: var(--font-heading);
  color: var(--color-dark);
}

.stat-card__label {
  font-size: var(--fs-xs);
  color: var(--color-dark-lighter);
  text-transform: uppercase;
  letter-spacing: 0.5px;
}

/* ────────────────────────────────────────────────────────────
   14. LEADERBOARD TABLE
   ──────────────────────────────────────────────────────────── */
.leaderboard {
  width: 100%;
  background: var(--color-white);
  border-radius: var(--radius-lg);
  overflow: hidden;
  box-shadow: var(--shadow-md);
}

.leaderboard__header {
  display: grid;
  grid-template-columns: 60px 1fr 120px 100px;
  padding: var(--space-md) var(--space-lg);
  background: var(--gradient-primary);
  color: var(--color-white);
  font-weight: 700;
  font-size: var(--fs-sm);
  text-transform: uppercase;
  letter-spacing: 0.5px;
}

.leaderboard__row {
  display: grid;
  grid-template-columns: 60px 1fr 120px 100px;
  padding: var(--space-md) var(--space-lg);
  align-items: center;
  border-bottom: 1px solid var(--color-gray-100);
  transition: background var(--transition-fast);
}

.leaderboard__row:hover {
  background: var(--color-gray-50);
}

.leaderboard__row:last-child {
  border-bottom: none;
}

.leaderboard__row--current {
  background: rgba(108,92,231,0.06);
  border-left: 3px solid var(--color-primary);
}

.leaderboard__rank {
  font-weight: 800;
  font-family: var(--font-heading);
  font-size: var(--fs-md);
}

.leaderboard__rank--1 {
  color: #FDCB6E;
}

.leaderboard__rank--2 {
  color: #B2BEC3;
}

.leaderboard__rank--3 {
  color: #E17055;
}

.leaderboard__user {
  display: flex;
  align-items: center;
  gap: var(--space-sm);
}

.leaderboard__user-avatar {
  width: 36px;
  height: 36px;
  border-radius: var(--radius-full);
  object-fit: cover;
}

.leaderboard__user-name {
  font-weight: 600;
  font-size: var(--fs-sm);
}

.leaderboard__score {
  font-weight: 700;
  font-family: var(--font-mono);
  font-size: var(--fs-sm);
  text-align: center;
}

.leaderboard__trend {
  text-align: center;
  font-size: var(--fs-sm);
}

.leaderboard__trend--up { color: var(--color-success); }
.leaderboard__trend--down { color: var(--color-error); }
.leaderboard__trend--same { color: var(--color-dark-lighter); }

@media (max-width: 768px) {
  .leaderboard__header,
  .leaderboard__row {
    grid-template-columns: 40px 1fr 80px;
  }

  .leaderboard__header > *:nth-child(4),
  .leaderboard__row > *:nth-child(4) {
    display: none;
  }
}

/* ────────────────────────────────────────────────────────────
   15. ARTICLE / BLOG CARDS
   ──────────────────────────────────────────────────────────── */
.article-card {
  background: var(--color-white);
  border-radius: var(--radius-lg);
  overflow: hidden;
  box-shadow: var(--shadow-sm);
  transition: all var(--transition-base);
  border: 1px solid var(--color-gray-100);
}

.article-card:hover {
  transform: translateY(-4px);
  box-shadow: var(--shadow-lg);
}

.article-card__image {
  width: 100%;
  height: 180px;
  object-fit: cover;
}

.article-card__content {
  padding: var(--space-lg);
}

.article-card__category {
  display: inline-block;
  padding: var(--space-xs) var(--space-sm);
  background: rgba(108,92,231,0.1);
  color: var(--color-primary);
  font-size: var(--fs-xs);
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 0.5px;
  border-radius: var(--radius-sm);
  margin-bottom: var(--space-sm);
}

.article-card__title {
  font-size: var(--fs-md);
  font-weight: 700;
  margin-bottom: var(--space-sm);
  line-height: 1.4;
  display: -webkit-box;
  -webkit-line-clamp: 2;
  -webkit-box-orient: vertical;
  overflow: hidden;
}

.article-card__title:hover {
  color: var(--color-primary);
}

.article-card__excerpt {
  font-size: var(--fs-sm);
  color: var(--color-dark-light);
  line-height: 1.6;
  display: -webkit-box;
  -webkit-line-clamp: 3;
  -webkit-box-orient: vertical;
  overflow: hidden;
  margin-bottom: var(--space-md);
}

.article-card__meta {
  display: flex;
  align-items: center;
  justify-content: space-between;
  font-size: var(--fs-xs);
  color: var(--color-dark-lighter);
}

.article-card__author {
  display: flex;
  align-items: center;
  gap: var(--space-xs);
}

.article-card__author-avatar {
  width: 24px;
  height: 24px;
  border-radius: var(--radius-full);
  object-fit: cover;
}

.article-card__read-time {
  display: flex;
  align-items: center;
  gap: var(--space-xs);
}

/* Featured article */
.article-card--featured {
  grid-column: 1 / -1;
  display: grid;
  grid-template-columns: 1fr;
}

@media (min-width: 768px) {
  .article-card--featured {
    grid-template-columns: 1fr 1fr;
  }

  .article-card--featured .article-card__image {
    height: 100%;
    min-height: 280px;
  }
}

/* ────────────────────────────────────────────────────────────
   16. WEEKLY QUIZ SECTION
   ──────────────────────────────────────────────────────────── */
.weekly-quiz {
  position: relative;
  padding: var(--space-3xl) 0;
  overflow: hidden;
}

.weekly-quiz__inner {
  background: var(--gradient-cool);
  border-radius: var(--radius-xl);
  padding: var(--space-3xl);
  color: var(--color-white);
  text-align: center;
  position: relative;
  overflow: hidden;
}

.weekly-quiz__badge {
  display: inline-flex;
  align-items: center;
  gap: var(--space-xs);
  padding: var(--space-xs) var(--space-md);
  background: rgba(255,255,255,0.2);
  border-radius: var(--radius-full);
  font-size: var(--fs-xs);
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 1px;
  margin-bottom: var(--space-md);
}

.weekly-quiz__title {
  font-size: var(--fs-2xl);
  color: var(--color-white);
  margin-bottom: var(--space-sm);
}

.weekly-quiz__description {
  font-size: var(--fs-md);
  color: rgba(255,255,255,0.85);
  margin-bottom: var(--space-xl);
  max-width: 500px;
  margin-inline: auto;
}

.weekly-quiz__countdown {
  display: flex;
  justify-content: center;
  gap: var(--space-md);
  margin-bottom: var(--space-xl);
}

.countdown-item {
  display: flex;
  flex-direction: column;
  align-items: center;
}

.countdown-item__value {
  font-size: var(--fs-2xl);
  font-weight: 800;
  font-family: var(--font-heading);
  background: rgba(255,255,255,0.15);
  backdrop-filter: blur(8px);
  padding: var(--space-sm) var(--space-md);
  border-radius: var(--radius-md);
  min-width: 60px;
}

.countdown-item__label {
  font-size: var(--fs-xs);
  text-transform: uppercase;
  letter-spacing: 1px;
  margin-top: var(--space-xs);
  opacity: 0.8;
}

/* Decorative elements */
.weekly-quiz__deco {
  position: absolute;
  border-radius: var(--radius-full);
  background: rgba(255,255,255,0.08);
  pointer-events: none;
}

.weekly-quiz__deco--1 {
  width: 200px; height: 200px;
  top: -60px; right: -40px;
  animation: float-slow 12s ease-in-out infinite;
}

.weekly-quiz__deco--2 {
  width: 150px; height: 150px;
  bottom: -50px; left: -30px;
  animation: float-slow 10s ease-in-out infinite reverse;
}

/* ────────────────────────────────────────────────────────────
   17. BREADCRUMB NAVIGATION
   ──────────────────────────────────────────────────────────── */
.breadcrumb {
  display: flex;
  align-items: center;
  gap: var(--space-sm);
  padding: var(--space-md) 0;
  font-size: var(--fs-sm);
  flex-wrap: wrap;
}

.breadcrumb__item {
  display: flex;
  align-items: center;
  gap: var(--space-sm);
}

.breadcrumb__link {
  color: var(--color-dark-lighter);
  transition: color var(--transition-fast);
}

.breadcrumb__link:hover {
  color: var(--color-primary);
}

.breadcrumb__separator {
  color: var(--color-gray-300);
  font-size: 0.8em;
}

.breadcrumb__current {
  color: var(--color-dark);
  font-weight: 600;
}

/* ────────────────────────────────────────────────────────────
   18. PAGINATION
   ──────────────────────────────────────────────────────────── */
.pagination {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: var(--space-sm);
  padding: var(--space-xl) 0;
}

.pagination__item {
  display: flex;
  align-items: center;
  justify-content: center;
  min-width: 40px;
  height: 40px;
  padding: 0 var(--space-sm);
  border: 2px solid var(--color-gray-100);
  border-radius: var(--radius-md);
  font-weight: 600;
  font-size: var(--fs-sm);
  cursor: pointer;
  transition: all var(--transition-fast);
  background: var(--color-white);
  color: var(--color-dark);
}

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

.pagination__item.active {
  background: var(--color-primary);
  border-color: var(--color-primary);
  color: var(--color-white);
  box-shadow: var(--shadow-glow-primary);
}

.pagination__item:disabled {
  opacity: 0.4;
  cursor: not-allowed;
  pointer-events: none;
}

.pagination__ellipsis {
  display: flex;
  align-items: center;
  justify-content: center;
  min-width: 40px;
  height: 40px;
  color: var(--color-dark-lighter);
  letter-spacing: 2px;
}

@media (max-width: 768px) {
  .pagination {
    gap: var(--space-xs);
  }

  .pagination__item {
    min-width: 34px;
    height: 34px;
    font-size: var(--fs-xs);
  }

  .pagination__item:not(.active):not(:first-child):not(:last-child) {
    display: none;
  }
}

/* ────────────────────────────────────────────────────────────
   19. TAGS & BADGES
   ──────────────────────────────────────────────────────────── */
.tag {
  display: inline-flex;
  align-items: center;
  gap: var(--space-xs);
  padding: var(--space-xs) var(--space-md);
  border-radius: var(--radius-full);
  font-size: var(--fs-xs);
  font-weight: 600;
  transition: all var(--transition-fast);
  cursor: default;
  white-space: nowrap;
}

.tag--primary {
  background: rgba(108,92,231,0.1);
  color: var(--color-primary);
}

.tag--primary:hover {
  background: rgba(108,92,231,0.2);
}

.tag--secondary {
  background: rgba(0,206,201,0.1);
  color: var(--color-secondary-dark);
}

.tag--secondary:hover {
  background: rgba(0,206,201,0.2);
}

.tag--accent {
  background: rgba(253,121,168,0.1);
  color: var(--color-accent-dark);
}

.tag--accent:hover {
  background: rgba(253,121,168,0.2);
}

.tag--success {
  background: rgba(0,184,148,0.1);
  color: #009B7D;
}

.tag--warning {
  background: rgba(253,203,110,0.15);
  color: var(--color-warning-dark);
}

.tag--error {
  background: rgba(255,107,107,0.1);
  color: var(--color-error-dark);
}

.tag--dark {
  background: var(--color-dark);
  color: var(--color-white);
}

/* Tags with remove button */
.tag--removable {
  cursor: pointer;
  padding-right: var(--space-xs);
}

.tag__remove {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 16px;
  height: 16px;
  border-radius: var(--radius-full);
  background: rgba(0,0,0,0.15);
  font-size: 0.7rem;
  cursor: pointer;
  transition: background var(--transition-fast);
}

.tag__remove:hover {
  background: rgba(0,0,0,0.3);
}

/* Badge */
.badge {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  padding: 2px 8px;
  border-radius: var(--radius-full);
  font-size: 0.7rem;
  font-weight: 800;
  text-transform: uppercase;
  letter-spacing: 0.5px;
  line-height: 1.4;
}

.badge--primary {
  background: var(--color-primary);
  color: var(--color-white);
}

.badge--secondary {
  background: var(--color-secondary);
  color: var(--color-white);
}

.badge--accent {
  background: var(--color-accent);
  color: var(--color-white);
}

.badge--success {
  background: var(--color-success);
  color: var(--color-white);
}

.badge--warning {
  background: var(--color-warning);
  color: var(--color-dark);
}

.badge--error {
  background: var(--color-error);
  color: var(--color-white);
}

/* Notification badge (dot) */
.badge--dot {
  width: 10px;
  height: 10px;
  padding: 0;
  border-radius: var(--radius-full);
  background: var(--color-error);
  position: absolute;
  top: -2px;
  right: -2px;
  border: 2px solid var(--color-white);
}

/* Tag list */
.tag-list {
  display: flex;
  flex-wrap: wrap;
  gap: var(--space-sm);
}

/* ────────────────────────────────────────────────────────────
   20. MODAL DIALOGS
   ──────────────────────────────────────────────────────────── */
.modal-overlay {
  position: fixed;
  inset: 0;
  background: rgba(45, 52, 54, 0.6);
  backdrop-filter: blur(4px);
  -webkit-backdrop-filter: blur(4px);
  z-index: var(--z-modal);
  display: flex;
  align-items: center;
  justify-content: center;
  padding: var(--space-lg);
  opacity: 0;
  visibility: hidden;
  transition: all var(--transition-base);
}

.modal-overlay.active {
  opacity: 1;
  visibility: visible;
}

.modal {
  background: var(--color-white);
  border-radius: var(--radius-xl);
  width: 100%;
  max-width: 500px;
  max-height: 90vh;
  overflow-y: auto;
  box-shadow: var(--shadow-xl);
  transform: scale(0.9) translateY(20px);
  transition: transform var(--transition-bounce);
}

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

.modal__header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: var(--space-lg);
  border-bottom: 1px solid var(--color-gray-100);
}

.modal__title {
  font-size: var(--fs-lg);
  font-weight: 700;
}

.modal__close {
  width: 36px;
  height: 36px;
  display: flex;
  align-items: center;
  justify-content: center;
  border: none;
  background: var(--color-gray-50);
  border-radius: var(--radius-full);
  cursor: pointer;
  font-size: var(--fs-md);
  color: var(--color-dark-light);
  transition: all var(--transition-fast);
}

.modal__close:hover {
  background: var(--color-gray-100);
  color: var(--color-dark);
}

.modal__body {
  padding: var(--space-lg);
}

.modal__footer {
  display: flex;
  justify-content: flex-end;
  gap: var(--space-sm);
  padding: var(--space-lg);
  border-top: 1px solid var(--color-gray-100);
}

/* Modal sizes */
.modal--sm { max-width: 380px; }
.modal--lg { max-width: 700px; }
.modal--xl { max-width: 900px; }

/* ────────────────────────────────────────────────────────────
   21. TOAST NOTIFICATIONS
   ──────────────────────────────────────────────────────────── */
.toast-container {
  position: fixed;
  top: var(--space-lg);
  right: var(--space-lg);
  z-index: var(--z-toast);
  display: flex;
  flex-direction: column;
  gap: var(--space-sm);
  pointer-events: none;
}

.toast {
  display: flex;
  align-items: center;
  gap: var(--space-md);
  padding: var(--space-md) var(--space-lg);
  background: var(--color-white);
  border-radius: var(--radius-md);
  box-shadow: var(--shadow-lg);
  min-width: 300px;
  max-width: 420px;
  pointer-events: auto;
  animation: slide-in-right 0.4s ease-out;
  border-left: 4px solid var(--color-primary);
}

.toast--success {
  border-left-color: var(--color-success);
}

.toast--error {
  border-left-color: var(--color-error);
}

.toast--warning {
  border-left-color: var(--color-warning-dark);
}

.toast--info {
  border-left-color: var(--color-info);
}

.toast__icon {
  font-size: 1.3rem;
  flex-shrink: 0;
}

.toast__content {
  flex: 1;
}

.toast__title {
  font-weight: 700;
  font-size: var(--fs-sm);
  margin-bottom: 2px;
}

.toast__message {
  font-size: var(--fs-xs);
  color: var(--color-dark-light);
  margin-bottom: 0;
}

.toast__close {
  background: none;
  border: none;
  cursor: pointer;
  color: var(--color-dark-lighter);
  font-size: var(--fs-md);
  padding: var(--space-xs);
  transition: color var(--transition-fast);
  flex-shrink: 0;
}

.toast__close:hover {
  color: var(--color-dark);
}

/* Toast exit animation */
.toast.removing {
  animation: slide-in-right 0.3s ease-in reverse forwards;
}

@media (max-width: 768px) {
  .toast-container {
    top: auto;
    bottom: var(--space-lg);
    right: var(--space-md);
    left: var(--space-md);
  }

  .toast {
    min-width: unset;
    max-width: unset;
    width: 100%;
  }
}

/* ────────────────────────────────────────────────────────────
   22. LOADING SPINNER
   ──────────────────────────────────────────────────────────── */
.spinner {
  display: inline-block;
  width: 40px;
  height: 40px;
  border: 4px solid var(--color-gray-100);
  border-top-color: var(--color-primary);
  border-radius: var(--radius-full);
  animation: spin 0.8s linear infinite;
}

.spinner--sm {
  width: 24px;
  height: 24px;
  border-width: 3px;
}

.spinner--lg {
  width: 56px;
  height: 56px;
  border-width: 5px;
}

.spinner--secondary {
  border-top-color: var(--color-secondary);
}

.spinner--accent {
  border-top-color: var(--color-accent);
}

/* Loading overlay */
.loading-overlay {
  position: fixed;
  inset: 0;
  background: rgba(255,255,255,0.85);
  backdrop-filter: blur(4px);
  -webkit-backdrop-filter: blur(4px);
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  gap: var(--space-md);
  z-index: var(--z-overlay);
}

.loading-overlay__text {
  font-size: var(--fs-md);
  color: var(--color-dark-light);
  font-weight: 500;
}

/* Skeleton loading */
.skeleton {
  background: linear-gradient(
    90deg,
    var(--color-gray-100) 25%,
    var(--color-gray-50) 50%,
    var(--color-gray-100) 75%
  );
  background-size: 200% 100%;
  animation: shimmer 1.5s ease-in-out infinite;
  border-radius: var(--radius-sm);
}

.skeleton--text {
  height: 16px;
  margin-bottom: var(--space-sm);
}

.skeleton--title {
  height: 28px;
  width: 60%;
  margin-bottom: var(--space-md);
}

.skeleton--circle {
  border-radius: var(--radius-full);
}

.skeleton--card {
  height: 250px;
  border-radius: var(--radius-lg);
}

/* ────────────────────────────────────────────────────────────
   23. FOOTER
   ──────────────────────────────────────────────────────────── */
.footer {
  background: var(--color-dark);
  color: rgba(255,255,255,0.7);
  padding: var(--space-4xl) 0 var(--space-lg);
}

.footer__grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: var(--space-2xl);
  margin-bottom: var(--space-2xl);
}

@media (min-width: 768px) {
  .footer__grid {
    grid-template-columns: 2fr 1fr 1fr 1fr;
  }
}

.footer__brand {
  max-width: 300px;
}

.footer__brand-logo {
  display: flex;
  align-items: center;
  gap: var(--space-sm);
  font-family: var(--font-heading);
  font-size: var(--fs-xl);
  font-weight: 800;
  color: var(--color-white);
  margin-bottom: var(--space-md);
}

.footer__brand-text {
  font-size: var(--fs-sm);
  line-height: 1.7;
  margin-bottom: var(--space-lg);
}

.footer__social {
  display: flex;
  gap: var(--space-sm);
}

.footer__social-link {
  width: 40px;
  height: 40px;
  display: flex;
  align-items: center;
  justify-content: center;
  border-radius: var(--radius-full);
  background: rgba(255,255,255,0.08);
  color: rgba(255,255,255,0.7);
  font-size: 1.1rem;
  transition: all var(--transition-fast);
}

.footer__social-link:hover {
  background: var(--color-primary);
  color: var(--color-white);
  transform: translateY(-2px);
}

.footer__column-title {
  font-size: var(--fs-md);
  font-weight: 700;
  color: var(--color-white);
  margin-bottom: var(--space-md);
}

.footer__link {
  display: block;
  padding: var(--space-xs) 0;
  color: rgba(255,255,255,0.6);
  font-size: var(--fs-sm);
  transition: all var(--transition-fast);
}

.footer__link:hover {
  color: var(--color-white);
  transform: translateX(4px);
}

.footer__bottom {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: var(--space-md);
  padding-top: var(--space-xl);
  border-top: 1px solid rgba(255,255,255,0.1);
  text-align: center;
}

@media (min-width: 768px) {
  .footer__bottom {
    flex-direction: row;
    justify-content: space-between;
    text-align: left;
  }
}

.footer__copyright {
  font-size: var(--fs-xs);
  color: rgba(255,255,255,0.5);
}

.footer__disclaimer {
  font-size: var(--fs-xs);
  color: rgba(255,255,255,0.4);
  font-style: italic;
  max-width: 500px;
}

.footer__legal-links {
  display: flex;
  gap: var(--space-md);
}

.footer__legal-link {
  font-size: var(--fs-xs);
  color: rgba(255,255,255,0.5);
  transition: color var(--transition-fast);
}

.footer__legal-link:hover {
  color: var(--color-white);
}

/* ────────────────────────────────────────────────────────────
   24. CONFETTI EFFECT
   ──────────────────────────────────────────────────────────── */
.confetti-container {
  position: fixed;
  inset: 0;
  pointer-events: none;
  z-index: var(--z-overlay);
  overflow: hidden;
}

.confetti-piece {
  position: absolute;
  top: -20px;
  width: 10px;
  height: 10px;
  animation: confetti-fall 3s ease-in forwards;
}

.confetti-piece:nth-child(odd) {
  animation: confetti-fall 3s ease-in forwards,
             confetti-sway 1.5s ease-in-out infinite;
}

.confetti-piece:nth-child(even) {
  animation: confetti-fall 2.5s ease-in forwards,
             confetti-sway 2s ease-in-out infinite reverse;
}

.confetti-piece:nth-child(3n) {
  border-radius: var(--radius-full);
}

.confetti-piece:nth-child(3n+1) {
  width: 8px;
  height: 14px;
  border-radius: 2px;
}

.confetti-piece:nth-child(3n+2) {
  width: 12px;
  height: 6px;
  border-radius: 1px;
}

/* Confetti colors */
.confetti-piece:nth-child(6n+1) { background: var(--color-primary); }
.confetti-piece:nth-child(6n+2) { background: var(--color-secondary); }
.confetti-piece:nth-child(6n+3) { background: var(--color-accent); }
.confetti-piece:nth-child(6n+4) { background: var(--color-warning); }
.confetti-piece:nth-child(6n+5) { background: var(--color-success); }
.confetti-piece:nth-child(6n+6) { background: var(--color-info); }

/* ────────────────────────────────────────────────────────────
   25. SECTION LAYOUT
   ──────────────────────────────────────────────────────────── */
.section {
  padding: var(--space-4xl) 0;
}

.section--alt {
  background: var(--color-gray-50);
}

.section--gradient {
  background: var(--gradient-hero);
  color: var(--color-white);
}

.section__header {
  text-align: center;
  max-width: 600px;
  margin: 0 auto var(--space-3xl);
}

.section__title {
  margin-bottom: var(--space-sm);
}

.section__subtitle {
  font-size: var(--fs-md);
  color: var(--color-dark-light);
  margin-bottom: 0;
}

.section--gradient .section__subtitle {
  color: rgba(255,255,255,0.8);
}

/* ────────────────────────────────────────────────────────────
   26. FORM ELEMENTS
   ──────────────────────────────────────────────────────────── */
.form-group {
  margin-bottom: var(--space-lg);
}

.form-label {
  display: block;
  font-weight: 600;
  font-size: var(--fs-sm);
  color: var(--color-dark);
  margin-bottom: var(--space-xs);
}

.form-input,
.form-textarea,
.form-select {
  width: 100%;
  padding: 0.7rem 1rem;
  border: 2px solid var(--color-gray-200);
  border-radius: var(--radius-md);
  font-size: var(--fs-base);
  background: var(--color-white);
  transition: all var(--transition-fast);
}

.form-input:focus,
.form-textarea:focus,
.form-select:focus {
  outline: none;
  border-color: var(--color-primary);
  box-shadow: 0 0 0 4px rgba(108,92,231,0.15);
}

.form-input::placeholder {
  color: var(--color-gray-300);
}

.form-input--error {
  border-color: var(--color-error);
}

.form-input--error:focus {
  box-shadow: 0 0 0 4px rgba(255,107,107,0.15);
}

.form-error {
  display: block;
  font-size: var(--fs-xs);
  color: var(--color-error);
  margin-top: var(--space-xs);
}

.form-hint {
  display: block;
  font-size: var(--fs-xs);
  color: var(--color-dark-lighter);
  margin-top: var(--space-xs);
}

.form-textarea {
  min-height: 120px;
  resize: vertical;
}

/* Search input */
.search-input {
  position: relative;
}

.search-input__icon {
  position: absolute;
  left: var(--space-md);
  top: 50%;
  transform: translateY(-50%);
  color: var(--color-gray-400);
  pointer-events: none;
}

.search-input .form-input {
  padding-left: 2.8rem;
}

/* Toggle switch */
.toggle {
  position: relative;
  display: inline-block;
  width: 48px;
  height: 26px;
}

.toggle__input {
  opacity: 0;
  width: 0;
  height: 0;
}

.toggle__slider {
  position: absolute;
  inset: 0;
  background: var(--color-gray-200);
  border-radius: var(--radius-full);
  cursor: pointer;
  transition: all var(--transition-base);
}

.toggle__slider::before {
  content: '';
  position: absolute;
  left: 3px;
  top: 3px;
  width: 20px;
  height: 20px;
  background: var(--color-white);
  border-radius: var(--radius-full);
  transition: all var(--transition-base);
  box-shadow: var(--shadow-sm);
}

.toggle__input:checked + .toggle__slider {
  background: var(--color-primary);
}

.toggle__input:checked + .toggle__slider::before {
  transform: translateX(22px);
}

.toggle__input:focus-visible + .toggle__slider {
  outline: 3px solid var(--color-primary);
  outline-offset: 3px;
}

/* ────────────────────────────────────────────────────────────
   27. TABS
   ──────────────────────────────────────────────────────────── */
.tabs {
  display: flex;
  gap: var(--space-xs);
  border-bottom: 2px solid var(--color-gray-100);
  margin-bottom: var(--space-xl);
  overflow-x: auto;
  -webkit-overflow-scrolling: touch;
  scrollbar-width: none;
}

.tabs::-webkit-scrollbar {
  display: none;
}

.tab {
  padding: var(--space-sm) var(--space-lg);
  font-weight: 600;
  font-size: var(--fs-sm);
  color: var(--color-dark-lighter);
  border: none;
  background: none;
  cursor: pointer;
  border-bottom: 3px solid transparent;
  margin-bottom: -2px;
  transition: all var(--transition-fast);
  white-space: nowrap;
}

.tab:hover {
  color: var(--color-primary);
}

.tab.active {
  color: var(--color-primary);
  border-bottom-color: var(--color-primary);
}

.tab__content {
  display: none;
  animation: fade-in 0.3s ease-out;
}

.tab__content.active {
  display: block;
}

/* ────────────────────────────────────────────────────────────
   28. TOOLTIP
   ──────────────────────────────────────────────────────────── */
.tooltip {
  position: relative;
}

.tooltip::after {
  content: attr(data-tooltip);
  position: absolute;
  bottom: calc(100% + 8px);
  left: 50%;
  transform: translateX(-50%);
  padding: var(--space-xs) var(--space-sm);
  background: var(--color-dark);
  color: var(--color-white);
  font-size: var(--fs-xs);
  font-weight: 500;
  border-radius: var(--radius-sm);
  white-space: nowrap;
  opacity: 0;
  visibility: hidden;
  transition: all var(--transition-fast);
  pointer-events: none;
  z-index: var(--z-tooltip);
}

.tooltip:hover::after {
  opacity: 1;
  visibility: visible;
}

.tooltip--bottom::after {
  top: calc(100% + 8px);
  bottom: auto;
}

.tooltip--left::after {
  top: 50%;
  right: calc(100% + 8px);
  bottom: auto;
  left: auto;
  transform: translateY(-50%);
}

.tooltip--right::after {
  top: 50%;
  left: calc(100% + 8px);
  bottom: auto;
  transform: translateY(-50%);
}

/* ────────────────────────────────────────────────────────────
   29. DROPDOWN MENU
   ──────────────────────────────────────────────────────────── */
.dropdown {
  position: relative;
}

.dropdown__menu {
  position: absolute;
  top: calc(100% + var(--space-sm));
  right: 0;
  min-width: 180px;
  background: var(--color-white);
  border-radius: var(--radius-md);
  box-shadow: var(--shadow-lg);
  border: 1px solid var(--color-gray-100);
  padding: var(--space-sm);
  opacity: 0;
  visibility: hidden;
  transform: translateY(-10px);
  transition: all var(--transition-fast);
  z-index: var(--z-dropdown);
}

.dropdown.open .dropdown__menu {
  opacity: 1;
  visibility: visible;
  transform: translateY(0);
}

.dropdown__item {
  display: flex;
  align-items: center;
  gap: var(--space-sm);
  padding: var(--space-sm) var(--space-md);
  border-radius: var(--radius-sm);
  font-size: var(--fs-sm);
  color: var(--color-dark);
  transition: background var(--transition-fast);
  cursor: pointer;
  border: none;
  background: none;
  width: 100%;
  text-align: left;
}

.dropdown__item:hover {
  background: var(--color-gray-50);
  color: var(--color-primary);
}

.dropdown__divider {
  height: 1px;
  background: var(--color-gray-100);
  margin: var(--space-xs) 0;
}

/* ────────────────────────────────────────────────────────────
   30. AVATAR GROUP
   ──────────────────────────────────────────────────────────── */
.avatar-group {
  display: flex;
  align-items: center;
}

.avatar-group__item {
  width: 36px;
  height: 36px;
  border-radius: var(--radius-full);
  border: 2px solid var(--color-white);
  object-fit: cover;
  margin-left: -10px;
  transition: transform var(--transition-fast);
}

.avatar-group__item:first-child {
  margin-left: 0;
}

.avatar-group__item:hover {
  transform: translateY(-4px);
  z-index: 1;
}

.avatar-group__overflow {
  width: 36px;
  height: 36px;
  border-radius: var(--radius-full);
  border: 2px solid var(--color-white);
  background: var(--color-primary-light);
  color: var(--color-primary-dark);
  font-size: var(--fs-xs);
  font-weight: 700;
  display: flex;
  align-items: center;
  justify-content: center;
  margin-left: -10px;
}

/* ────────────────────────────────────────────────────────────
   31. PROGRESS BAR VARIANTS
   ──────────────────────────────────────────────────────────── */
.progress {
  width: 100%;
  height: 10px;
  background: var(--color-gray-100);
  border-radius: var(--radius-full);
  overflow: hidden;
}

.progress--sm {
  height: 6px;
}

.progress--lg {
  height: 16px;
}

.progress__fill {
  height: 100%;
  border-radius: var(--radius-full);
  transition: width 0.6s cubic-bezier(0.4, 0, 0.2, 1);
}

.progress__fill--primary { background: var(--gradient-primary); }
.progress__fill--secondary { background: var(--gradient-secondary); }
.progress__fill--accent { background: var(--gradient-accent); }
.progress__fill--success { background: var(--color-success); }
.progress__fill--warning { background: var(--color-warning-dark); }
.progress__fill--error { background: var(--color-error); }

/* Striped progress */
.progress__fill--striped {
  background-image: linear-gradient(
    45deg,
    rgba(255,255,255,0.15) 25%,
    transparent 25%,
    transparent 50%,
    rgba(255,255,255,0.15) 50%,
    rgba(255,255,255,0.15) 75%,
    transparent 75%
  );
  background-size: 1rem 1rem;
}

.progress__fill--striped.animated {
  animation: shimmer 1s linear infinite;
}

/* Progress with label */
.progress--labeled {
  position: relative;
}

.progress__label {
  position: absolute;
  top: 50%;
  left: 50%;
  transform: translate(-50%, -50%);
  font-size: 0.7rem;
  font-weight: 700;
  color: var(--color-dark);
  text-shadow: 0 0 3px var(--color-white);
}

/* ────────────────────────────────────────────────────────────
   32. EMPTY STATE
   ──────────────────────────────────────────────────────────── */
.empty-state {
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  padding: var(--space-4xl) var(--space-xl);
  text-align: center;
}

.empty-state__icon {
  font-size: 4rem;
  margin-bottom: var(--space-lg);
  opacity: 0.5;
}

.empty-state__title {
  font-size: var(--fs-xl);
  margin-bottom: var(--space-sm);
}

.empty-state__text {
  font-size: var(--fs-md);
  color: var(--color-dark-lighter);
  max-width: 400px;
  margin-bottom: var(--space-xl);
}

/* ────────────────────────────────────────────────────────────
   33. DIFFICULTY INDICATOR
   ──────────────────────────────────────────────────────────── */
.difficulty {
  display: inline-flex;
  align-items: center;
  gap: 3px;
}

.difficulty__dot {
  width: 8px;
  height: 8px;
  border-radius: var(--radius-full);
  background: var(--color-gray-200);
  transition: background var(--transition-fast);
}

.difficulty--easy .difficulty__dot:nth-child(1) { background: var(--color-success); }

.difficulty--medium .difficulty__dot:nth-child(1),
.difficulty--medium .difficulty__dot:nth-child(2) { background: var(--color-warning-dark); }

.difficulty--hard .difficulty__dot:nth-child(1),
.difficulty--hard .difficulty__dot:nth-child(2),
.difficulty--hard .difficulty__dot:nth-child(3) { background: var(--color-error); }

.difficulty--expert .difficulty__dot:nth-child(1),
.difficulty--expert .difficulty__dot:nth-child(2),
.difficulty--expert .difficulty__dot:nth-child(3),
.difficulty--expert .difficulty__dot:nth-child(4) { background: var(--color-primary); }

.difficulty__label {
  font-size: var(--fs-xs);
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 0.5px;
  margin-left: var(--space-xs);
}

/* ────────────────────────────────────────────────────────────
   34. CHIP / FILTER PILLS
   ──────────────────────────────────────────────────────────── */
.chip-group {
  display: flex;
  flex-wrap: wrap;
  gap: var(--space-sm);
  margin-bottom: var(--space-xl);
}

.chip {
  padding: var(--space-sm) var(--space-md);
  background: var(--color-white);
  border: 2px solid var(--color-gray-100);
  border-radius: var(--radius-full);
  font-size: var(--fs-sm);
  font-weight: 500;
  cursor: pointer;
  transition: all var(--transition-fast);
}

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

.chip.active {
  background: var(--color-primary);
  border-color: var(--color-primary);
  color: var(--color-white);
}

/* ────────────────────────────────────────────────────────────
   35. NOTIFICATION BELL
   ──────────────────────────────────────────────────────────── */
.notification-bell {
  position: relative;
  display: flex;
  align-items: center;
  justify-content: center;
  width: 40px;
  height: 40px;
  border-radius: var(--radius-full);
  background: var(--color-gray-50);
  cursor: pointer;
  transition: all var(--transition-fast);
  border: none;
  font-size: 1.2rem;
}

.notification-bell:hover {
  background: var(--color-gray-100);
}

.notification-bell__count {
  position: absolute;
  top: 2px;
  right: 2px;
  width: 18px;
  height: 18px;
  background: var(--color-error);
  color: var(--color-white);
  font-size: 0.65rem;
  font-weight: 700;
  border-radius: var(--radius-full);
  display: flex;
  align-items: center;
  justify-content: center;
  border: 2px solid var(--color-white);
}

/* ────────────────────────────────────────────────────────────
   36. DARK MODE OVERRIDES
   ──────────────────────────────────────────────────────────── */
@media (prefers-color-scheme: dark) {
  :root {
    --color-off-white: #1a1a2e;
    --color-white: #16213e;
    --color-gray-50: #1a1a2e;
    --color-gray-100: #232946;
    --color-gray-200: #2d3561;
    --color-gray-300: #3a417d;
    --color-gray-400: #5a5f9e;
    --color-dark: #e8e8e8;
    --color-dark-light: #b0b0c0;
    --color-dark-lighter: #8888a0;
    --shadow-sm: 0 1px 3px rgba(0,0,0,0.3);
    --shadow-md: 0 4px 6px rgba(0,0,0,0.4);
    --shadow-lg: 0 10px 25px rgba(0,0,0,0.5);
    --shadow-xl: 0 20px 50px rgba(0,0,0,0.6);
    --glass-bg: rgba(22, 33, 62, 0.7);
    --glass-border: rgba(255,255,255,0.08);
  }

  body {
    background-color: #0f0f23;
    color: #e8e8e8;
  }

  .card,
  .quiz-question,
  .leaderboard,
  .radar-chart-container,
  .profile-card,
  .modal,
  .toast,
  .stat-card,
  .article-card {
    background: #1a1a2e;
    border-color: rgba(255,255,255,0.08);
  }

  .section--alt {
    background: #0f0f23;
  }
}

/* Manual dark mode class */
body.dark-mode {
  --color-off-white: #1a1a2e;
  --color-white: #16213e;
  --color-gray-50: #1a1a2e;
  --color-gray-100: #232946;
  --color-gray-200: #2d3561;
  --color-dark: #e8e8e8;
  --color-dark-light: #b0b0c0;
  --color-dark-lighter: #8888a0;
  background-color: #0f0f23;
  color: #e8e8e8;
}

body.dark-mode .card,
body.dark-mode .quiz-question,
body.dark-mode .leaderboard,
body.dark-mode .modal,
body.dark-mode .toast {
  background: #1a1a2e;
  border-color: rgba(255,255,255,0.08);
}

/* ────────────────────────────────────────────────────────────
   37. PRINT STYLES
   ──────────────────────────────────────────────────────────── */
@media print {
  .navbar,
  .footer,
  .modal-overlay,
  .toast-container,
  .btn,
  .confetti-container,
  .loading-overlay {
    display: none !important;
  }

  body {
    background: white;
    color: black;
  }

  .card {
    break-inside: avoid;
    box-shadow: none;
    border: 1px solid #ddd;
  }

  .text-gradient,
  .text-gradient-primary,
  .text-gradient-accent {
    -webkit-text-fill-color: initial;
    background: none;
    color: var(--color-dark);
  }
}

/* ────────────────────────────────────────────────────────────
   38. RESPONSIVE UTILITIES
   ──────────────────────────────────────────────────────────── */
@media (max-width: 768px) {
  .hide-mobile {
    display: none !important;
  }

  .section {
    padding: var(--space-2xl) 0;
  }

  .quiz-question {
    padding: var(--space-lg);
  }

  .leaderboard__header,
  .leaderboard__row {
    padding: var(--space-sm) var(--space-md);
  }

  .modal {
    max-width: 100%;
    border-radius: var(--radius-lg);
  }

  .hero__cta-group {
    flex-direction: column;
    align-items: center;
  }

  .hero__cta-group .btn {
    width: 100%;
    max-width: 280px;
  }

  .game-board--sudoku .game-cell--sudoku {
    font-size: clamp(0.7rem, 2.5vw, 1rem);
  }
}

@media (min-width: 769px) {
  .hide-desktop {
    display: none !important;
  }
}

@media (min-width: 1024px) {
  .container--narrow {
    max-width: 800px;
  }
}

/* ────────────────────────────────────────────────────────────
   39. SCROLLBAR STYLES
   ──────────────────────────────────────────────────────────── */
::-webkit-scrollbar {
  width: 8px;
  height: 8px;
}

::-webkit-scrollbar-track {
  background: var(--color-gray-50);
}

::-webkit-scrollbar-thumb {
  background: var(--color-gray-300);
  border-radius: var(--radius-full);
}

::-webkit-scrollbar-thumb:hover {
  background: var(--color-gray-400);
}

/* Firefox */
* {
  scrollbar-width: thin;
  scrollbar-color: var(--color-gray-300) var(--color-gray-50);
}

/* ────────────────────────────────────────────────────────────
   40. SELECTION STYLES
   ──────────────────────────────────────────────────────────── */
::selection {
  background: rgba(108, 92, 231, 0.25);
  color: var(--color-dark);
}

/* ────────────────────────────────────────────────────────────
   END OF STYLESHEET
   IQGAME v1.0.0
   ──────────────────────────────────────────────────────────── */