/* ============================================
   DSA Practice Platform - Modern Design System
   Vibrant & Tech-forward with Indigo/Purple Theme
   ============================================ */

/* CSS Custom Properties */
:root {
  /* Primary Colors - Indigo/Purple */
  --primary-50: #eef2ff;
  --primary-100: #e0e7ff;
  --primary-200: #c7d2fe;
  --primary-300: #a5b4fc;
  --primary-400: #818cf8;
  --primary-500: #6366f1;
  --primary-600: #4f46e5;
  --primary-700: #4338ca;
  --primary-800: #3730a3;
  --primary-900: #312e81;
  
  /* Accent Colors */
  --accent-purple: #a855f7;
  --accent-pink: #ec4899;
  --accent-cyan: #06b6d4;
  
  /* Neutral Colors */
  --gray-50: #f9fafb;
  --gray-100: #f3f4f6;
  --gray-200: #e5e7eb;
  --gray-300: #d1d5db;
  --gray-400: #9ca3af;
  --gray-500: #6b7280;
  --gray-600: #4b5563;
  --gray-700: #374151;
  --gray-800: #1f2937;
  --gray-900: #111827;
  
  /* Difficulty Colors */
  --easy-color: #10b981;
  --easy-bg: #d1fae5;
  --medium-color: #f59e0b;
  --medium-bg: #fef3c7;
  --hard-color: #ef4444;
  --hard-bg: #fee2e2;
  
  /* Shadows */
  --shadow-sm: 0 1px 2px 0 rgb(0 0 0 / 0.05);
  --shadow-md: 0 4px 6px -1px rgb(0 0 0 / 0.1), 0 2px 4px -2px rgb(0 0 0 / 0.1);
  --shadow-lg: 0 10px 15px -3px rgb(0 0 0 / 0.1), 0 4px 6px -4px rgb(0 0 0 / 0.1);
  --shadow-xl: 0 20px 25px -5px rgb(0 0 0 / 0.1), 0 8px 10px -6px rgb(0 0 0 / 0.1);
  --shadow-glow: 0 0 20px rgba(99, 102, 241, 0.3);
  
  /* Border Radius */
  --radius-sm: 0.375rem;
  --radius-md: 0.5rem;
  --radius-lg: 0.75rem;
  --radius-xl: 1rem;
  --radius-2xl: 1.5rem;
  
  /* Transitions */
  --transition-fast: 150ms ease;
  --transition-base: 200ms ease;
  --transition-slow: 300ms ease;
  
  /* Spacing */
  --container-max: 1200px;
  --container-padding: 1.5rem;
}

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

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

body {
  font-family: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
  background: linear-gradient(135deg, var(--gray-50) 0%, var(--primary-50) 50%, var(--gray-50) 100%);
  background-attachment: fixed;
  color: var(--gray-800);
  line-height: 1.6;
  min-height: 100vh;
}

/* Typography */
h1, h2, h3, h4, h5, h6 {
  font-weight: 700;
  line-height: 1.2;
  color: var(--gray-900);
}

h1 { font-size: 2.5rem; }
h2 { font-size: 2rem; }
h3 { font-size: 1.5rem; }
h4 { font-size: 1.25rem; }

@media (max-width: 768px) {
  h1 { font-size: 1.875rem; }
  h2 { font-size: 1.5rem; }
  h3 { font-size: 1.25rem; }
}

/* Container */
.container {
  max-width: var(--container-max);
  margin: 0 auto;
  padding: 0 var(--container-padding);
}

/* ============================================
   Navigation Header
   ============================================ */
.header {
  background: rgba(255, 255, 255, 0.9);
  backdrop-filter: blur(10px);
  border-bottom: 1px solid var(--gray-200);
  position: sticky;
  top: 0;
  z-index: 100;
  padding: 1rem 0;
}

.header-content {
  display: flex;
  align-items: center;
  justify-content: space-between;
  max-width: var(--container-max);
  margin: 0 auto;
  padding: 0 var(--container-padding);
}

.header-logo {
  display: flex;
  align-items: center;
  gap: 0.75rem;
  text-decoration: none;
  color: var(--gray-900);
  font-weight: 700;
  font-size: 1.25rem;
}

.header-logo svg,
.header-logo .logo-icon {
  width: 2rem;
  height: 2rem;
  color: var(--primary-500);
}

.header-nav {
  display: flex;
  align-items: center;
  gap: 1rem;
}

.nav-link {
  display: inline-flex;
  align-items: center;
  gap: 0.5rem;
  padding: 0.5rem 1rem;
  color: var(--gray-600);
  text-decoration: none;
  font-weight: 500;
  font-size: 0.875rem;
  border-radius: var(--radius-md);
  transition: all var(--transition-base);
}

.nav-link:hover {
  color: var(--primary-600);
  background: var(--primary-50);
}

.nav-link.active {
  color: var(--primary-600);
  background: var(--primary-100);
}

/* ============================================
   Hero Section (Index Page)
   ============================================ */
.hero {
  text-align: center;
  padding: 4rem 0 3rem;
  position: relative;
}

.hero::before {
  content: '';
  position: absolute;
  top: 0;
  left: 50%;
  transform: translateX(-50%);
  width: 100%;
  max-width: 600px;
  height: 400px;
  background: radial-gradient(ellipse at center, rgba(99, 102, 241, 0.15) 0%, transparent 70%);
  pointer-events: none;
  z-index: -1;
}

.hero-title {
  font-size: 3rem;
  font-weight: 800;
  background: linear-gradient(135deg, var(--primary-600), var(--accent-purple), var(--accent-pink));
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
  margin-bottom: 1rem;
  animation: fadeInUp 0.6s ease-out;
}

.hero-subtitle {
  font-size: 1.25rem;
  color: var(--gray-600);
  max-width: 600px;
  margin: 0 auto 2rem;
  animation: fadeInUp 0.6s ease-out 0.1s both;
}

@media (max-width: 768px) {
  .hero {
    padding: 2rem 0;
  }
  .hero-title {
    font-size: 2rem;
  }
  .hero-subtitle {
    font-size: 1rem;
    padding: 0 1rem;
  }
}

/* ============================================
   Navigation Cards (Index Page)
   ============================================ */
.nav-cards {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
  gap: 1.5rem;
  max-width: 900px;
  margin: 0 auto;
  padding: 0 var(--container-padding);
  animation: fadeInUp 0.6s ease-out 0.2s both;
}

.nav-card {
  background: white;
  border-radius: var(--radius-xl);
  padding: 2rem;
  text-decoration: none;
  color: inherit;
  position: relative;
  overflow: hidden;
  transition: all var(--transition-slow);
  border: 1px solid var(--gray-200);
  box-shadow: var(--shadow-md);
}

.nav-card::before {
  content: '';
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  height: 4px;
  background: linear-gradient(90deg, var(--primary-500), var(--accent-purple));
  transform: scaleX(0);
  transform-origin: left;
  transition: transform var(--transition-slow);
}

.nav-card:hover {
  transform: translateY(-4px);
  box-shadow: var(--shadow-xl), var(--shadow-glow);
  border-color: var(--primary-200);
}

.nav-card:hover::before {
  transform: scaleX(1);
}

.nav-card-icon {
  width: 3.5rem;
  height: 3.5rem;
  display: flex;
  align-items: center;
  justify-content: center;
  background: linear-gradient(135deg, var(--primary-500), var(--accent-purple));
  border-radius: var(--radius-lg);
  margin-bottom: 1.25rem;
  color: white;
  font-size: 1.5rem;
}

.nav-card-icon svg {
  width: 1.75rem;
  height: 1.75rem;
}

.nav-card-title {
  font-size: 1.25rem;
  font-weight: 700;
  color: var(--gray-900);
  margin-bottom: 0.5rem;
}

.nav-card-description {
  font-size: 0.9rem;
  color: var(--gray-500);
  margin-bottom: 1rem;
}

.nav-card-stats {
  display: flex;
  align-items: center;
  gap: 0.5rem;
  font-size: 0.875rem;
  color: var(--primary-600);
  font-weight: 600;
}

.nav-card-stats svg {
  width: 1rem;
  height: 1rem;
}

/* ============================================
   Page Layout
   ============================================ */
.page-container {
  max-width: var(--container-max);
  margin: 0 auto;
  padding: 2rem var(--container-padding);
}

.page-title {
  text-align: center;
  margin-bottom: 2rem;
}

.page-title h1 {
  font-size: 2rem;
  background: linear-gradient(135deg, var(--primary-600), var(--accent-purple));
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
  margin-bottom: 0.5rem;
}

.page-title p {
  color: var(--gray-500);
}

/* ============================================
   Cards & Sections
   ============================================ */
.card {
  background: white;
  border-radius: var(--radius-xl);
  padding: 1.5rem;
  border: 1px solid var(--gray-200);
  box-shadow: var(--shadow-md);
}

.card-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  margin-bottom: 1rem;
  padding-bottom: 1rem;
  border-bottom: 1px solid var(--gray-100);
}

.card-title {
  font-size: 1.125rem;
  font-weight: 600;
  color: var(--gray-900);
}

.section-title {
  font-size: 1rem;
  font-weight: 600;
  color: var(--gray-700);
  margin-bottom: 1rem;
  display: flex;
  align-items: center;
  gap: 0.5rem;
}

.section-title svg {
  width: 1.25rem;
  height: 1.25rem;
  color: var(--primary-500);
}

/* ============================================
   Company Cards Grid
   ============================================ */

   

.company-card {
  width: 150px;     /* your card size */
  height: 100px;
  display: flex;
  align-items: center;
  justify-content: center;
}

.company-card-name {
  display: flex;
  align-items: center;
  justify-content: center;
  width: 100%;
  height: 100%;
}

.company-card img {
  max-width: 100%;
  max-height: 100%;
  object-fit: contain;
}



.company-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(140px, 1fr));
  gap: 1rem;
  margin-bottom: 2rem;
}

.company-card {
  background: white;
  border: 2px solid var(--gray-200);
  border-radius: var(--radius-lg);
  padding: 1.25rem 1rem;
  text-align: center;
  cursor: pointer;
  transition: all var(--transition-base);
  position: relative;
  overflow: hidden;
}

.company-card::before {
  content: '';
  position: absolute;
  inset: 0;
  background: linear-gradient(135deg, var(--primary-500), var(--accent-purple));
  opacity: 0;
  transition: opacity var(--transition-base);
}

.company-card:hover {
  border-color: var(--primary-300);
  transform: translateY(-2px);
  box-shadow: var(--shadow-md);
}

.company-card.selected {
  border-color: var(--primary-500);
  background: var(--primary-50);
  box-shadow: 0 0 0 3px rgba(99, 102, 241, 0.2);
}

.company-card.selected::after {
  content: '✓';
  position: absolute;
  top: 0.5rem;
  right: 0.5rem;
  width: 1.25rem;
  height: 1.25rem;
  background: var(--primary-500);
  color: white;
  border-radius: 50%;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 0.75rem;
  font-weight: bold;
}

.company-card-name {
  font-weight: 600;
  color: var(--gray-800);
  font-size: 0.9rem;
  position: relative;
  z-index: 1;
}

@media (max-width: 640px) {
  .company-grid {
    grid-template-columns: repeat(2, 1fr);
    gap: 0.75rem;
  }
  .company-card {
    padding: 1rem 0.75rem;
  }
}

/* ============================================
   Topic Pills/Tags
   ============================================ */
.topics-grid {
  display: flex;
  flex-wrap: wrap;
  gap: 0.625rem;
  margin-bottom: 1.5rem;
}

.topic-pill {
  display: inline-flex;
  align-items: center;
  gap: 0.375rem;
  padding: 0.5rem 0.875rem;
  background: var(--gray-100);
  border: 1px solid var(--gray-200);
  border-radius: 9999px;
  cursor: pointer;
  transition: all var(--transition-base);
  font-size: 0.875rem;
  color: var(--gray-700);
  user-select: none;
}

.topic-pill:hover {
  background: var(--primary-50);
  border-color: var(--primary-300);
  color: var(--primary-700);
}

.topic-pill.selected {
  background: linear-gradient(135deg, var(--primary-500), var(--accent-purple));
  border-color: transparent;
  color: white;
  font-weight: 500;
}

.topic-pill input[type="checkbox"] {
  display: none;
}

/* Legacy tag class for JS compatibility */
.tag {
  display: inline-flex;
  align-items: center;
  gap: 0.375rem;
  padding: 0.5rem 0.875rem;
  background: var(--gray-100);
  border: 1px solid var(--gray-200);
  border-radius: 9999px;
  cursor: pointer;
  transition: all var(--transition-base);
  font-size: 0.875rem;
  color: var(--gray-700);
  user-select: none;
}

.tag:hover {
  background: var(--primary-50);
  border-color: var(--primary-300);
  color: var(--primary-700);
}

.tag.selected,
.tag input[type="checkbox"]:checked + span,
label.tag:has(input:checked) {
  background: linear-gradient(135deg, var(--primary-500), var(--accent-purple));
  border-color: transparent;
  color: white;
  font-weight: 500;
}

/* ============================================
   Difficulty Badges
   ============================================ */
.difficulty-options {
  display: flex;
  flex-wrap: wrap;
  gap: 0.75rem;
  margin-bottom: 1.5rem;
}

.difficulty-badge {
  display: inline-flex;
  align-items: center;
  gap: 0.5rem;
  padding: 0.625rem 1rem;
  border-radius: var(--radius-md);
  cursor: pointer;
  transition: all var(--transition-base);
  font-size: 0.875rem;
  font-weight: 500;
  border: 2px solid transparent;
  user-select: none;
}

.difficulty-badge.easy {
  background: var(--easy-bg);
  color: var(--easy-color);
  border-color: var(--easy-color);
}

.difficulty-badge.medium {
  background: var(--medium-bg);
  color: var(--medium-color);
  border-color: var(--medium-color);
}

.difficulty-badge.hard {
  background: var(--hard-bg);
  color: var(--hard-color);
  border-color: var(--hard-color);
}

.difficulty-badge:not(.selected) {
  opacity: 0.6;
  border-color: transparent;
}

.difficulty-badge.selected {
  opacity: 1;
  box-shadow: var(--shadow-md);
  transform: scale(1.02);
}

.difficulty-badge input[type="checkbox"] {
  display: none;
}

/* Legacy difficulty class for JS compatibility */
.difficulty {
  display: inline-flex;
  align-items: center;
  gap: 0.5rem;
  padding: 0.625rem 1rem;
  border-radius: var(--radius-md);
  cursor: pointer;
  transition: all var(--transition-base);
  font-size: 0.875rem;
  font-weight: 500;
  border: 2px solid var(--gray-300);
  background: var(--gray-100);
  color: var(--gray-600);
  user-select: none;
}

.difficulty:hover {
  border-color: var(--primary-300);
}

.difficulty.selected,
label.difficulty:has(input:checked) {
  background: linear-gradient(135deg, var(--primary-500), var(--accent-purple));
  border-color: transparent;
  color: white;
}

/* ============================================
   Form Elements
   ============================================ */
.form-group {
  margin-bottom: 1.25rem;
}

.form-label {
  display: block;
  font-size: 0.875rem;
  font-weight: 600;
  color: var(--gray-700);
  margin-bottom: 0.5rem;
}

.form-input {
  width: 100%;
  padding: 0.75rem 1rem;
  font-size: 1rem;
  border: 2px solid var(--gray-200);
  border-radius: var(--radius-md);
  background: white;
  color: var(--gray-900);
  transition: all var(--transition-base);
}

.form-input:focus {
  outline: none;
  border-color: var(--primary-500);
  box-shadow: 0 0 0 3px rgba(99, 102, 241, 0.15);
}

.form-input::placeholder {
  color: var(--gray-400);
}

.form-row {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(150px, 1fr));
  gap: 1rem;
}

/* ============================================
   Buttons
   ============================================ */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 0.5rem;
  padding: 0.75rem 1.5rem;
  font-size: 1rem;
  font-weight: 600;
  border-radius: var(--radius-md);
  border: none;
  cursor: pointer;
  transition: all var(--transition-base);
  text-decoration: none;
}

.btn-primary {
  background: linear-gradient(135deg, var(--primary-500), var(--primary-600));
  color: white;
  box-shadow: var(--shadow-md), 0 0 20px rgba(99, 102, 241, 0.3);
}

.btn-primary:hover {
  background: linear-gradient(135deg, var(--primary-600), var(--primary-700));
  transform: translateY(-2px);
  box-shadow: var(--shadow-lg), 0 0 30px rgba(99, 102, 241, 0.4);
}

.btn-primary:active {
  transform: translateY(0);
}

.btn-secondary {
  background: white;
  color: var(--primary-600);
  border: 2px solid var(--primary-200);
}

.btn-secondary:hover {
  background: var(--primary-50);
  border-color: var(--primary-400);
}

.btn-ghost {
  background: transparent;
  color: var(--gray-600);
  padding: 0.5rem;
}

.btn-ghost:hover {
  background: var(--gray-100);
  color: var(--gray-900);
}

.btn-lg {
  padding: 1rem 2rem;
  font-size: 1.125rem;
}

.btn-block {
  width: 100%;
}

/* ============================================
   Help Button & Tooltip
   ============================================ */
.help-container {
  position: relative;
  display: inline-block;
}

.help-btn {
  width: 2rem;
  height: 2rem;
  display: flex;
  align-items: center;
  justify-content: center;
  background: var(--gray-100);
  border: 1px solid var(--gray-200);
  border-radius: 50%;
  cursor: pointer;
  color: var(--gray-500);
  font-size: 0.875rem;
  font-weight: 600;
  transition: all var(--transition-base);
}

.help-btn:hover {
  background: var(--primary-100);
  border-color: var(--primary-300);
  color: var(--primary-600);
}

.help-tooltip {
  position: absolute;
  top: calc(100% + 0.5rem);
  right: 0;
  width: 300px;
  padding: 1rem;
  background: var(--gray-900);
  color: white;
  border-radius: var(--radius-lg);
  font-size: 0.875rem;
  line-height: 1.5;
  box-shadow: var(--shadow-xl);
  display: none;
  z-index: 1000;
}


.help-tooltip.show,
.help-tooltip.visible {
  opacity: 1;
  visibility: visible;
  transform: translateY(0);
}

.help-tooltip::before {
  content: '';
  position: absolute;
  top: -6px;
  right: 0.75rem;
  width: 12px;
  height: 12px;
  background: var(--gray-900);
  transform: rotate(45deg);
}

@media (max-width: 640px) {
  .help-tooltip {
    width: 250px;
    right: -1rem;
  }
}

/* ============================================
   Results Section
   ============================================ */
.results-container {
  margin-top: 2rem;
}

.results-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  margin-bottom: 1rem;
}

.results-title {
  font-size: 1.25rem;
  font-weight: 700;
  color: var(--gray-900);
}

.results-count {
  font-size: 0.875rem;
  color: var(--gray-500);
}

.results-grid {
  display: grid;
  gap: 1rem;
}

.result-card {
  background: white;
  border: 1px solid var(--gray-200);
  border-radius: var(--radius-lg);
  padding: 1.25rem;
  transition: all var(--transition-base);
}

.result-card:hover {
  border-color: var(--primary-200);
  box-shadow: var(--shadow-md);
}

.result-card-header {
  display: flex;
  align-items: flex-start;
  justify-content: space-between;
  gap: 1rem;
  margin-bottom: 0.75rem;
}

.result-card-title {
  font-size: 1rem;
  font-weight: 600;
  color: var(--primary-600);
  text-decoration: none;
}

.result-card-title:hover {
  text-decoration: underline;
}

.result-card-difficulty {
  font-size: 0.75rem;
  font-weight: 600;
  padding: 0.25rem 0.625rem;
  border-radius: 9999px;
  text-transform: capitalize;
}

.result-card-difficulty.easy {
  background: var(--easy-bg);
  color: var(--easy-color);
}

.result-card-difficulty.medium {
  background: var(--medium-bg);
  color: var(--medium-color);
}

.result-card-difficulty.hard {
  background: var(--hard-bg);
  color: var(--hard-color);
}

.result-card-meta {
  display: flex;
  flex-wrap: wrap;
  gap: 0.5rem;
  font-size: 0.8rem;
  color: var(--gray-500);
}

.result-card-tag {
  background: var(--gray-100);
  padding: 0.25rem 0.5rem;
  border-radius: var(--radius-sm);
}

/* ============================================
   Selection Panel
   ============================================ */
.selection-panel {
  background: linear-gradient(135deg, var(--primary-50), var(--primary-100));
  border: 1px solid var(--primary-200);
  border-radius: var(--radius-xl);
  padding: 1.5rem;
  margin-bottom: 2rem;
}

.selection-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  margin-bottom: 1rem;
}

.selection-title {
  font-weight: 600;
  color: var(--primary-800);
}

.selection-actions {
  display: flex;
  gap: 0.5rem;
}

/* ============================================
   Footer
   ============================================ */
.footer {
  text-align: center;
  padding: 2rem var(--container-padding);
  margin-top: 4rem;
  border-top: 1px solid var(--gray-200);
  color: var(--gray-500);
  font-size: 0.875rem;
}

.footer a {
  color: var(--primary-600);
  text-decoration: none;
  font-weight: 500;
}

.footer a:hover {
  text-decoration: underline;
}

/* ============================================
   Animations
   ============================================ */
@keyframes fadeInUp {
  from {
    opacity: 0;
    transform: translateY(20px);
  }
  to {
    opacity: 1;
    transform: translateY(0);
  }
}

@keyframes fadeIn {
  from { opacity: 0; }
  to { opacity: 1; }
}

@keyframes pulse {
  0%, 100% { opacity: 1; }
  50% { opacity: 0.5; }
}

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

.animate-fade-in {
  animation: fadeIn 0.3s ease-out;
}

.animate-fade-in-up {
  animation: fadeInUp 0.4s ease-out;
}

.animate-pulse {
  animation: pulse 2s cubic-bezier(0.4, 0, 0.6, 1) infinite;
}

.animate-spin {
  animation: spin 1s linear infinite;
}

/* Stagger animation delays */
.stagger-1 { animation-delay: 0.1s; }
.stagger-2 { animation-delay: 0.2s; }
.stagger-3 { animation-delay: 0.3s; }

/* ============================================
   Loading States
   ============================================ */
.loading {
  display: flex;
  align-items: center;
  justify-content: center;
  padding: 3rem;
  color: var(--gray-500);
}

.loading-spinner {
  width: 2rem;
  height: 2rem;
  border: 3px solid var(--gray-200);
  border-top-color: var(--primary-500);
  border-radius: 50%;
  animation: spin 0.8s linear infinite;
}

/* ============================================
   Empty State
   ============================================ */
.empty-state {
  text-align: center;
  padding: 3rem 1.5rem;
  color: var(--gray-500);
}

.empty-state-icon {
  font-size: 3rem;
  margin-bottom: 1rem;
  opacity: 0.5;
}

.empty-state-title {
  font-size: 1.125rem;
  font-weight: 600;
  color: var(--gray-700);
  margin-bottom: 0.5rem;
}

.empty-state-text {
  font-size: 0.875rem;
}

/* ============================================
   Utility Classes
   ============================================ */
.text-center { text-align: center; }
.text-left { text-align: left; }
.text-right { text-align: right; }

.mt-1 { margin-top: 0.25rem; }
.mt-2 { margin-top: 0.5rem; }
.mt-3 { margin-top: 0.75rem; }
.mt-4 { margin-top: 1rem; }
.mt-6 { margin-top: 1.5rem; }
.mt-8 { margin-top: 2rem; }

.mb-1 { margin-bottom: 0.25rem; }
.mb-2 { margin-bottom: 0.5rem; }
.mb-3 { margin-bottom: 0.75rem; }
.mb-4 { margin-bottom: 1rem; }
.mb-6 { margin-bottom: 1.5rem; }
.mb-8 { margin-bottom: 2rem; }

.flex { display: flex; }
.flex-wrap { flex-wrap: wrap; }
.items-center { align-items: center; }
.justify-center { justify-content: center; }
.justify-between { justify-content: space-between; }
.gap-1 { gap: 0.25rem; }
.gap-2 { gap: 0.5rem; }
.gap-3 { gap: 0.75rem; }
.gap-4 { gap: 1rem; }

.hidden { display: none; }
.block { display: block; }
.inline-block { display: inline-block; }

.w-full { width: 100%; }

.font-medium { font-weight: 500; }
.font-semibold { font-weight: 600; }
.font-bold { font-weight: 700; }

.text-sm { font-size: 0.875rem; }
.text-base { font-size: 1rem; }
.text-lg { font-size: 1.125rem; }
.text-xl { font-size: 1.25rem; }

.text-gray-500 { color: var(--gray-500); }
.text-gray-600 { color: var(--gray-600); }
.text-primary { color: var(--primary-600); }

/* ============================================
   Responsive Visibility
   ============================================ */
@media (max-width: 640px) {
  .hide-mobile { display: none !important; }
}

@media (min-width: 641px) {
  .show-mobile-only { display: none !important; }
}