/* ============================================
   QuizMaster 3D - Custom Styling
   Modern 3D WebApp with stunning visuals
   ============================================ */

/* CSS Variables */
:root {
  --primary: #6366f1;
  --primary-dark: #4f46e5;
  --secondary: #ec4899;
  --success: #10b981;
  --warning: #f59e0b;
  --danger: #ef4444;
  --dark: #1e1e2e;
  --dark-light: #2d2d44;
  --light: #f8fafc;
  --gray: #64748b;
  
  --gradient-primary: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
  --gradient-success: linear-gradient(135deg, #11998e 0%, #38ef7d 100%);
  --gradient-danger: linear-gradient(135deg, #eb3349 0%, #f45c43 100%);
  --gradient-bg: linear-gradient(135deg, #1e1e2e 0%, #2d2d44 50%, #1e1e2e 100%);
  
  --shadow-sm: 0 2px 4px rgba(0, 0, 0, 0.1);
  --shadow-md: 0 4px 12px rgba(0, 0, 0, 0.15);
  --shadow-lg: 0 8px 32px rgba(0, 0, 0, 0.2);
  --shadow-3d: 0 15px 35px rgba(0, 0, 0, 0.3), 0 5px 15px rgba(0, 0, 0, 0.2);
  
  --radius-sm: 8px;
  --radius-md: 12px;
  --radius-lg: 20px;
  --radius-xl: 30px;
  
  --transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
}

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

html {
  scroll-behavior: smooth;
}

body {
  font-family: 'Segoe UI', system-ui, -apple-system, sans-serif;
  background: var(--gradient-bg);
  color: var(--light);
  min-height: 100vh;
  overflow-x: hidden;
  line-height: 1.6;
}

/* Animated Background */
body::before {
  content: '';
  position: fixed;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  background: 
    radial-gradient(circle at 20% 80%, rgba(99, 102, 241, 0.15) 0%, transparent 50%),
    radial-gradient(circle at 80% 20%, rgba(236, 72, 153, 0.15) 0%, transparent 50%),
    radial-gradient(circle at 40% 40%, rgba(16, 185, 129, 0.1) 0%, transparent 40%);
  pointer-events: none;
  z-index: -1;
}

/* Typography */
h1, h2, h3, h4 {
  font-weight: 700;
  line-height: 1.2;
}

h1 {
  font-size: clamp(2.5rem, 5vw, 4rem);
  text-transform: uppercase;
  letter-spacing: 0.1em;
}

h2 {
  font-size: clamp(1.8rem, 3vw, 2.5rem);
}

h3 {
  font-size: clamp(1.3rem, 2vw, 1.8rem);
}

/* Container */
.container {
  max-width: 1200px;
  margin: 0 auto;
  padding: 0 20px;
}

/* ============================================
   3D Card Styles
   ============================================ */

.card-3d {
  perspective: 1000px;
  transform-style: preserve-3d;
  transition: var(--transition);
}

.card-3d:hover {
  transform: translateY(-10px) rotateX(5deg);
}

.card-front, .card-back {
  background: rgba(255, 255, 255, 0.05);
  backdrop-filter: blur(10px);
  border: 1px solid rgba(255, 255, 255, 0.1);
  border-radius: var(--radius-lg);
  padding: 30px;
  box-shadow: var(--shadow-3d);
  transition: var(--transition);
}

.card-3d:hover .card-front {
  box-shadow: var(--shadow-3d), 0 0 30px rgba(99, 102, 241, 0.3);
}

/* ============================================
   Navbar 3D
   ============================================ */

.navbar-3d {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 15px 30px;
  background: rgba(30, 30, 46, 0.9);
  backdrop-filter: blur(20px);
  border-bottom: 1px solid rgba(255, 255, 255, 0.1);
  position: sticky;
  top: 0;
  z-index: 1000;
  box-shadow: var(--shadow-lg);
}

.nav-brand {
  display: flex;
  align-items: center;
  gap: 10px;
}

.brand-link {
  display: flex;
  align-items: center;
  gap: 10px;
  text-decoration: none;
  color: var(--light);
}

.brand-icon {
  font-size: 2rem;
  animation: bounce 2s infinite;
}

.brand-text {
  font-size: 1.5rem;
  font-weight: 700;
  background: var(--gradient-primary);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}

.nav-links {
  display: flex;
  gap: 20px;
}

.nav-link {
  color: var(--light);
  text-decoration: none;
  padding: 8px 16px;
  border-radius: var(--radius-md);
  transition: var(--transition);
  font-weight: 500;
}

.nav-link:hover {
  background: rgba(255, 255, 255, 0.1);
  transform: translateY(-2px);
}

.nav-link.logout {
  background: rgba(239, 68, 68, 0.2);
  border: none;
  cursor: pointer;
}

.nav-link.logout:hover {
  background: rgba(239, 68, 68, 0.4);
}

.nav-user {
  display: flex;
  align-items: center;
  gap: 12px;
}

.user-name {
  font-weight: 600;
}

.user-level {
  padding: 4px 12px;
  border-radius: var(--radius-xl);
  font-size: 0.85rem;
  font-weight: 700;
  background: var(--primary);
  animation: glow 2s infinite;
}

/* ============================================
   Hero Section
   ============================================ */

.hero {
  min-height: calc(100vh - 80px);
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  text-align: center;
  padding: 40px 20px;
  position: relative;
}

.hero-title {
  font-size: clamp(3rem, 8vw, 6rem);
  margin-bottom: 20px;
  background: var(--gradient-primary);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
  text-shadow: 0 0 60px rgba(99, 102, 241, 0.5);
  animation: float 3s ease-in-out infinite;
}

.hero-subtitle {
  font-size: 1.3rem;
  color: var(--gray);
  margin-bottom: 40px;
  max-width: 600px;
}

/* 3D Floating Elements */
.floating-shapes {
  position: absolute;
  width: 100%;
  height: 100%;
  top: 0;
  left: 0;
  pointer-events: none;
  overflow: hidden;
}

.shape {
  position: absolute;
  border-radius: 50%;
  filter: blur(60px);
  opacity: 0.5;
  animation: float 6s ease-in-out infinite;
}

.shape-1 {
  width: 300px;
  height: 300px;
  background: var(--primary);
  top: 10%;
  left: 10%;
  animation-delay: 0s;
}

.shape-2 {
  width: 200px;
  height: 200px;
  background: var(--secondary);
  top: 60%;
  right: 10%;
  animation-delay: 2s;
}

.shape-3 {
  width: 150px;
  height: 150px;
  background: var(--success);
  bottom: 20%;
  left: 20%;
  animation-delay: 4s;
}

/* ============================================
   Login Section
   ============================================ */

.login-section {
  width: 100%;
  max-width: 450px;
  margin: 0 auto;
}

.login-card {
  background: rgba(255, 255, 255, 0.05);
  backdrop-filter: blur(20px);
  border: 1px solid rgba(255, 255, 255, 0.1);
  border-radius: var(--radius-xl);
  padding: 40px;
  box-shadow: var(--shadow-3d);
  transform: perspective(1000px) rotateX(0deg);
  transition: var(--transition);
}

.login-card:hover {
  transform: perspective(1000px) rotateX(2deg) translateY(-5px);
  box-shadow: var(--shadow-3d), 0 0 40px rgba(99, 102, 241, 0.2);
}

.login-title {
  text-align: center;
  margin-bottom: 30px;
  font-size: 1.8rem;
}

/* Form Styles */
.form-group {
  margin-bottom: 25px;
}

.form-label {
  display: block;
  margin-bottom: 10px;
  font-weight: 600;
  color: var(--light);
}

.form-input {
  width: 100%;
  padding: 16px 20px;
  border: 2px solid rgba(255, 255, 255, 0.1);
  border-radius: var(--radius-md);
  background: rgba(255, 255, 255, 0.05);
  color: var(--light);
  font-size: 1rem;
  transition: var(--transition);
}

.form-input:focus {
  outline: none;
  border-color: var(--primary);
  box-shadow: 0 0 20px rgba(99, 102, 241, 0.3);
  transform: scale(1.02);
}

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

/* Buttons */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 10px;
  padding: 16px 32px;
  border: none;
  border-radius: var(--radius-md);
  font-size: 1rem;
  font-weight: 700;
  cursor: pointer;
  transition: var(--transition);
  text-decoration: none;
  position: relative;
  overflow: hidden;
}

.btn::before {
  content: '';
  position: absolute;
  top: 0;
  left: -100%;
  width: 100%;
  height: 100%;
  background: linear-gradient(90deg, transparent, rgba(255, 255, 255, 0.2), transparent);
  transition: left 0.5s;
}

.btn:hover::before {
  left: 100%;
}

.btn-primary {
  background: var(--gradient-primary);
  color: white;
  width: 100%;
  padding: 18px;
  font-size: 1.1rem;
  box-shadow: 0 4px 20px rgba(99, 102, 241, 0.4);
}

.btn-primary:hover {
  transform: translateY(-3px) scale(1.02);
  box-shadow: 0 8px 30px rgba(99, 102, 241, 0.5);
}

.btn-secondary {
  background: rgba(255, 255, 255, 0.1);
  color: var(--light);
  border: 2px solid rgba(255, 255, 255, 0.2);
}

.btn-secondary:hover {
  background: rgba(255, 255, 255, 0.2);
  transform: translateY(-2px);
}

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

/* ============================================
   Difficulty Selector
   ============================================ */

.difficulty-section {
  margin: 40px 0;
}

.difficulty-title {
  text-align: center;
  margin-bottom: 20px;
  color: var(--gray);
}

.difficulty-buttons {
  display: flex;
  gap: 15px;
  justify-content: center;
  flex-wrap: wrap;
}

.difficulty-btn {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 8px;
  padding: 20px 30px;
  border: 2px solid rgba(255, 255, 255, 0.1);
  border-radius: var(--radius-lg);
  background: rgba(255, 255, 255, 0.05);
  color: var(--light);
  cursor: pointer;
  transition: var(--transition);
  min-width: 120px;
}

.difficulty-btn:hover {
  transform: translateY(-5px) scale(1.05);
  border-color: var(--btn-color, var(--primary));
  box-shadow: 0 10px 30px rgba(0, 0, 0, 0.3);
}

.difficulty-btn.active {
  border-color: var(--btn-color, var(--primary));
  background: rgba(99, 102, 241, 0.2);
  box-shadow: 0 0 30px rgba(99, 102, 241, 0.3);
  transform: translateY(-5px);
}

.difficulty-icon {
  font-size: 1.5rem;
}

.difficulty-label {
  font-weight: 700;
  font-size: 1.1rem;
}

/* ============================================
   Welcome Section (Logged In)
   ============================================ */

.welcome-section {
  display: none;
  text-align: center;
  animation: fadeIn 0.5s ease;
}

.welcome-card {
  background: rgba(255, 255, 255, 0.05);
  backdrop-filter: blur(20px);
  border: 1px solid rgba(255, 255, 255, 0.1);
  border-radius: var(--radius-xl);
  padding: 40px;
  box-shadow: var(--shadow-3d);
}

.welcome-avatar {
  width: 100px;
  height: 100px;
  border-radius: 50%;
  background: var(--gradient-primary);
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 3rem;
  margin: 0 auto 20px;
  box-shadow: 0 0 30px rgba(99, 102, 241, 0.5);
  animation: pulse 2s infinite;
}

.welcome-username {
  font-size: 2rem;
  margin-bottom: 10px;
}

.welcome-stats {
  display: flex;
  gap: 30px;
  justify-content: center;
  margin: 30px 0;
}

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

.stat-value {
  font-size: 1.8rem;
  font-weight: 700;
  color: var(--primary);
}

.stat-label {
  font-size: 0.9rem;
  color: var(--gray);
}

/* ============================================
   Quiz Page Styles
   ============================================ */

.quiz-container {
  max-width: 800px;
  margin: 0 auto;
  padding: 40px 20px;
}

.quiz-header {
  display: flex;
  justify-content: space-between;
  align-items: center;
  margin-bottom: 30px;
  flex-wrap: wrap;
  gap: 15px;
}

.quiz-progress {
  flex: 1;
}

.progress-text {
  font-size: 1rem;
  margin-bottom: 10px;
  color: var(--gray);
}

.progress-bar {
  height: 8px;
  background: rgba(255, 255, 255, 0.1);
  border-radius: var(--radius-xl);
  overflow: hidden;
}

.progress-fill {
  height: 100%;
  background: var(--gradient-primary);
  border-radius: var(--radius-xl);
  transition: width 0.5s ease;
}

.quiz-stats {
  display: flex;
  gap: 20px;
}

.quiz-stat {
  padding: 10px 20px;
  background: rgba(255, 255, 255, 0.05);
  border-radius: var(--radius-md);
  font-weight: 600;
}

.timer {
  font-size: 1.3rem;
  font-weight: 700;
}

/* Question Card */
.question-card {
  background: rgba(255, 255, 255, 0.05);
  backdrop-filter: blur(20px);
  border: 1px solid rgba(255, 255, 255, 0.1);
  border-radius: var(--radius-xl);
  padding: 40px;
  box-shadow: var(--shadow-3d);
  margin-bottom: 30px;
}

.question-text {
  font-size: 1.5rem;
  font-weight: 600;
  text-align: center;
  margin-bottom: 30px;
  line-height: 1.5;
}

/* Answer Buttons */
.answers-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
  gap: 15px;
}

.answer-btn {
  display: flex;
  align-items: center;
  gap: 15px;
  padding: 18px 24px;
  border: 2px solid rgba(255, 255, 255, 0.1);
  border-radius: var(--radius-lg);
  background: rgba(255, 255, 255, 0.05);
  color: var(--light);
  font-size: 1rem;
  cursor: pointer;
  transition: var(--transition);
  text-align: left;
}

.answer-btn:hover:not(:disabled) {
  transform: translateX(10px);
  border-color: var(--primary);
  background: rgba(99, 102, 241, 0.1);
  box-shadow: 0 0 20px rgba(99, 102, 241, 0.2);
}

.answer-btn:disabled {
  cursor: not-allowed;
  opacity: 0.7;
}

.answer-btn.correct {
  border-color: var(--success);
  background: rgba(16, 185, 129, 0.2);
  animation: correctPulse 0.5s ease;
}

.answer-btn.incorrect {
  border-color: var(--danger);
  background: rgba(239, 68, 68, 0.2);
  animation: shake 0.5s ease;
}

.answer-letter {
  width: 40px;
  height: 40px;
  display: flex;
  align-items: center;
  justify-content: center;
  border-radius: 50%;
  background: rgba(255, 255, 255, 0.1);
  font-weight: 700;
  flex-shrink: 0;
}

.answer-btn:hover:not(:disabled) .answer-letter {
  background: var(--primary);
}

.answer-text {
  flex: 1;
}

/* Feedback */
.feedback {
  position: fixed;
  top: 50%;
  left: 50%;
  transform: translate(-50%, -50%);
  padding: 30px 50px;
  border-radius: var(--radius-xl);
  font-size: 1.5rem;
  font-weight: 700;
  z-index: 100;
  animation: popIn 0.3s ease;
  display: flex;
  align-items: center;
  gap: 15px;
}

.feedback-correct {
  background: var(--gradient-success);
  color: white;
  box-shadow: 0 0 40px rgba(16, 185, 129, 0.5);
}

.feedback-incorrect {
  background: var(--gradient-danger);
  color: white;
  box-shadow: 0 0 40px rgba(239, 68, 68, 0.5);
}

/* ============================================
   Result Page Styles
   ============================================ */

.result-container {
  max-width: 600px;
  margin: 0 auto;
  padding: 40px 20px;
  text-align: center;
}

.result-card {
  background: rgba(255, 255, 255, 0.05);
  backdrop-filter: blur(20px);
  border: 1px solid rgba(255, 255, 255, 0.1);
  border-radius: var(--radius-xl);
  padding: 50px 40px;
  box-shadow: var(--shadow-3d);
}

.result-icon {
  font-size: 5rem;
  margin-bottom: 20px;
  animation: bounce 1s infinite;
}

.result-rating {
  font-size: 2.5rem;
  font-weight: 700;
  margin-bottom: 30px;
  background: var(--gradient-primary);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}

.result-score {
  font-size: 4rem;
  font-weight: 700;
  margin-bottom: 10px;
}

.result-xp {
  font-size: 1.5rem;
  color: var(--success);
  margin-bottom: 30px;
}

.result-stats {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 20px;
  margin-bottom: 40px;
}

.result-stat {
  padding: 20px;
  background: rgba(255, 255, 255, 0.05);
  border-radius: var(--radius-lg);
}

.result-stat-value {
  font-size: 2rem;
  font-weight: 700;
  color: var(--primary);
}

.result-stat-label {
  font-size: 0.9rem;
  color: var(--gray);
}

.result-buttons {
  display: flex;
  gap: 15px;
  justify-content: center;
  flex-wrap: wrap;
}

/* Confetti */
.confetti-container {
  position: fixed;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  pointer-events: none;
  z-index: 1000;
  overflow: hidden;
}

.confetti {
  position: absolute;
  top: -20px;
  border-radius: 2px;
  animation: confettiFall 3s linear forwards;
}

/* ============================================
   Profile Page Styles
   ============================================ */

.profile-container {
  max-width: 800px;
  margin: 0 auto;
  padding: 40px 20px;
}

.profile-header {
  text-align: center;
  margin-bottom: 40px;
}

.profile-avatar {
  width: 150px;
  height: 150px;
  border-radius: 50%;
  background: var(--gradient-primary);
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 4rem;
  margin: 0 auto 20px;
  box-shadow: 0 0 50px rgba(99, 102, 241, 0.5);
  animation: pulse 2s infinite;
}

.profile-username {
  font-size: 2.5rem;
  font-weight: 700;
  margin-bottom: 10px;
}

.profile-level {
  display: inline-block;
  padding: 8px 24px;
  border-radius: var(--radius-xl);
  font-size: 1.2rem;
  font-weight: 700;
  margin-bottom: 10px;
}

.level-title {
  color: var(--gray);
  font-size: 1.1rem;
}

/* XP Bar */
.xp-section {
  background: rgba(255, 255, 255, 0.05);
  backdrop-filter: blur(20px);
  border: 1px solid rgba(255, 255, 255, 0.1);
  border-radius: var(--radius-xl);
  padding: 30px;
  margin-bottom: 30px;
  box-shadow: var(--shadow-lg);
}

.xp-header {
  display: flex;
  justify-content: space-between;
  margin-bottom: 15px;
}

.xp-label {
  font-weight: 600;
}

.xp-value {
  color: var(--primary);
  font-weight: 700;
}

.xp-bar {
  height: 20px;
  background: rgba(255, 255, 255, 0.1);
  border-radius: var(--radius-xl);
  overflow: hidden;
}

.xp-bar-fill {
  height: 100%;
  background: var(--gradient-primary);
  border-radius: var(--radius-xl);
  transition: width 1s ease;
  position: relative;
}

.xp-bar-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);
  animation: shimmer 2s infinite;
}

.xp-footer {
  display: flex;
  justify-content: space-between;
  margin-top: 10px;
  font-size: 0.9rem;
  color: var(--gray);
}

/* Stats Grid */
.stats-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(150px, 1fr));
  gap: 20px;
  margin-bottom: 30px;
}

.stat-card {
  background: rgba(255, 255, 255, 0.05);
  backdrop-filter: blur(10px);
  border: 1px solid rgba(255, 255, 255, 0.1);
  border-radius: var(--radius-lg);
  padding: 25px;
  text-align: center;
  transition: var(--transition);
}

.stat-card:hover {
  transform: translateY(-5px);
  box-shadow: var(--shadow-lg);
}

.stat-icon {
  font-size: 2rem;
  margin-bottom: 10px;
}

.stat-value {
  font-size: 2rem;
  font-weight: 700;
  color: var(--primary);
  margin-bottom: 5px;
}

.stat-label {
  font-size: 0.9rem;
  color: var(--gray);
}

/* Profile Actions */
.profile-actions {
  display: flex;
  gap: 15px;
  justify-content: center;
  flex-wrap: wrap;
}

/* ============================================
   Animations
   ============================================ */

@keyframes bounce {
  0%, 100% { transform: translateY(0); }
  50% { transform: translateY(-10px); }
}

@keyframes float {
  0%, 100% { transform: translateY(0) rotate(0deg); }
  50% { transform: translateY(-20px) rotate(5deg); }
}

@keyframes pulse {
  0%, 100% { transform: scale(1); box-shadow: 0 0 30px rgba(99, 102, 241, 0.5); }
  50% { transform: scale(1.05); box-shadow: 0 0 50px rgba(99, 102, 241, 0.8); }
}

@keyframes glow {
  0%, 100% { box-shadow: 0 0 20px rgba(99, 102, 241, 0.5); }
  50% { box-shadow: 0 0 40px rgba(99, 102, 241, 0.8); }
}

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

@keyframes popIn {
  0% { transform: translate(-50%, -50%) scale(0); }
  70% { transform: translate(-50%, -50%) scale(1.1); }
  100% { transform: translate(-50%, -50%) scale(1); }
}

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

@keyframes correctPulse {
  0% { transform: scale(1); }
  50% { transform: scale(1.05); }
  100% { transform: scale(1); }
}

@keyframes shimmer {
  0% { transform: translateX(-100%); }
  100% { transform: translateX(100%); }
}

@keyframes confettiFall {
  0% {
    top: -20px;
    transform: rotate(0deg);
    opacity: 1;
  }
  100% {
    top: 100vh;
    transform: rotate(720deg);
    opacity: 0;
  }
}

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

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

/* ============================================
   Responsive Design
   ============================================ */

@media (max-width: 768px) {
  .navbar-3d {
    flex-direction: column;
    gap: 15px;
    padding: 15px;
  }
  
  .nav-links {
    order: 3;
    width: 100%;
    justify-content: center;
  }
  
  .hero-title {
    font-size: 2.5rem;
  }
  
  .login-card {
    padding: 30px 20px;
  }
  
  .difficulty-buttons {
    flex-direction: column;
  }
  
  .difficulty-btn {
    width: 100%;
  }
  
  .quiz-header {
    flex-direction: column;
  }
  
  .quiz-stats {
    width: 100%;
    justify-content: space-between;
  }
  
  .answers-grid {
    grid-template-columns: 1fr;
  }
  
  .result-stats {
    grid-template-columns: 1fr;
  }
  
  .stats-grid {
    grid-template-columns: repeat(2, 1fr);
  }
}

@media (max-width: 480px) {
  .container {
    padding: 0 15px;
  }
  
  .welcome-stats {
    flex-direction: column;
    gap: 15px;
  }
  
  .profile-avatar {
    width: 100px;
    height: 100px;
    font-size: 2.5rem;
  }
  
  .profile-username {
    font-size: 1.8rem;
  }
  
  .result-score {
    font-size: 3rem;
  }
}

/* ============================================
   Utility Classes
   ============================================ */

.text-center { text-align: center; }
.text-primary { color: var(--primary); }
.text-success { color: var(--success); }
.text-danger { color: var(--danger); }
.text-warning { color: var(--warning); }
.text-gray { color: var(--gray); }

.mt-1 { margin-top: 10px; }
.mt-2 { margin-top: 20px; }
.mt-3 { margin-top: 30px; }
.mt-4 { margin-top: 40px; }

.mb-1 { margin-bottom: 10px; }
.mb-2 { margin-bottom: 20px; }
.mb-3 { margin-bottom: 30px; }
.mb-4 { margin-bottom: 40px; }

.hidden { display: none !important; }
.visible { display: block !important; }

/* Loading Spinner */
.spinner {
  width: 50px;
  height: 50px;
  border: 4px solid rgba(255, 255, 255, 0.1);
  border-top-color: var(--primary);
  border-radius: 50%;
  animation: spin 1s linear infinite;
}

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

/* Page Loader */
.page-loader {
  position: fixed;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  background: var(--dark);
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  z-index: 9999;
}

.page-loader-text {
  margin-top: 20px;
  font-size: 1.2rem;
  color: var(--gray);
}