* {
  margin: 0;
  padding: 0;
  box-sizing: border-box;
}

:root {
  --bg-primary: #0f0f0f;
  --bg-secondary: #1a1a1a;
  --bg-tertiary: #2a2a2a;
  --text-primary: #ffffff;
  --text-secondary: #b3b3b3;
  --text-muted: #666666;
  --accent-success: #22c55e;
  --accent-danger: #ef4444;
  --accent-warning: #f59e0b;
  --accent-info: #3b82f6;
  --accent-purple: #8b5cf6;
  --border-color: #333333;
  --shadow: 0 4px 6px -1px rgba(0, 0, 0, 0.3);
  --shadow-lg: 0 10px 15px -3px rgba(0, 0, 0, 0.4);
  --transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
}

body {
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto,
    "Helvetica Neue", Arial, sans-serif;
  background: linear-gradient(135deg, var(--bg-primary) 0%, #1a1a2e 100%);
  color: var(--text-primary);
  line-height: 1.6;
  min-height: 100vh;
}

.container {
  max-width: 1400px;
  margin: 0 auto;
  padding: 2rem 1rem;
  min-height: 100vh;
  display: flex;
  flex-direction: column;
}

header {
  text-align: center;
  margin-bottom: 3rem;
  opacity: 0;
  animation: slideInDown 0.8s ease-out 0.2s forwards;
}

header h1 {
  font-size: 3rem;
  font-weight: 700;
  margin-bottom: 0.5rem;
  background: linear-gradient(135deg, var(--accent-info), var(--accent-success), var(--accent-purple));
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
  background-size: 200% 200%;
  animation: gradientShift 3s ease-in-out infinite;
}

.subtitle {
  color: var(--text-secondary);
  font-size: 1.2rem;
  margin-bottom: 2rem;
}

/* Statistics Overview */
.stats-overview {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 1rem;
  margin-top: 2rem;
  opacity: 0;
  animation: fadeInUp 0.8s ease-out 0.4s forwards;
}

.stat-card {
  background: rgba(255, 255, 255, 0.05);
  backdrop-filter: blur(10px);
  border: 1px solid rgba(255, 255, 255, 0.1);
  border-radius: 12px;
  padding: 1.5rem;
  text-align: center;
  transition: var(--transition);
}

.stat-card:hover {
  transform: translateY(-5px);
  background: rgba(255, 255, 255, 0.08);
}

.stat-value {
  font-size: 2rem;
  font-weight: 700;
  color: var(--accent-info);
  display: block;
}

.stat-label {
  color: var(--text-secondary);
  font-size: 0.9rem;
  margin-top: 0.5rem;
}

/* Controls */
.controls {
  display: flex;
  justify-content: space-between;
  align-items: center;
  margin-bottom: 2rem;
  padding: 1rem;
  background: var(--bg-secondary);
  border-radius: 12px;
  border: 1px solid var(--border-color);
  opacity: 0;
  animation: fadeInUp 0.8s ease-out 0.6s forwards;
}

.filter-group {
  display: flex;
  align-items: center;
  gap: 1rem;
}

.filter-group label {
  color: var(--text-secondary);
  font-weight: 500;
}

.filter-select {
  background: var(--bg-tertiary);
  color: var(--text-primary);
  border: 1px solid var(--border-color);
  border-radius: 8px;
  padding: 0.5rem 1rem;
  font-size: 0.9rem;
  transition: var(--transition);
}

.filter-select:focus {
  outline: none;
  border-color: var(--accent-info);
  box-shadow: 0 0 0 3px rgba(59, 130, 246, 0.1);
}

.view-toggle {
  display: flex;
  gap: 0.5rem;
}

.view-btn {
  background: var(--bg-tertiary);
  color: var(--text-secondary);
  border: 1px solid var(--border-color);
  border-radius: 8px;
  padding: 0.5rem;
  cursor: pointer;
  transition: var(--transition);
  display: flex;
  align-items: center;
  justify-content: center;
}

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

.view-btn.active {
  color: var(--accent-info);
  background: rgba(59, 130, 246, 0.1);
  border-color: var(--accent-info);
}

/* Loading Spinner */
.loading-spinner {
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  height: 300px;
  gap: 1rem;
}

.spinner {
  width: 50px;
  height: 50px;
  border: 3px solid var(--border-color);
  border-top: 3px solid var(--accent-info);
  border-radius: 50%;
  animation: spin 1s linear infinite;
}

.loading-spinner p {
  color: var(--text-secondary);
}

/* Charts Grid */
main {
  flex: 1;
}

.charts-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(380px, 1fr));
  gap: 2rem;
  margin-bottom: 2rem;
}

.charts-grid.list-view {
  grid-template-columns: 1fr;
  max-width: 800px;
  margin: 0 auto 2rem;
}

.chart-card {
  background: var(--bg-secondary);
  border-radius: 16px;
  padding: 2rem;
  box-shadow: var(--shadow-lg);
  border: 1px solid var(--border-color);
  transition: var(--transition);
  position: relative;
  overflow: hidden;
  opacity: 0;
  transform: translateY(30px);
}

.chart-card::before {
  content: '';
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  height: 3px;
  background: linear-gradient(90deg, var(--accent-info), var(--accent-success));
  transform: scaleX(0);
  transition: transform 0.3s ease;
}

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

.chart-card:hover {
  transform: translateY(-8px);
  box-shadow: 0 25px 50px -12px rgba(0, 0, 0, 0.6);
  border-color: rgba(255, 255, 255, 0.2);
}

.chart-card.loaded {
  animation: slideInUp 0.6s ease-out forwards;
}

/* Group Badge */
.group-badge {
  display: inline-block;
  background: var(--accent-info);
  color: white;
  padding: 0.25rem 0.75rem;
  border-radius: 20px;
  font-size: 0.75rem;
  font-weight: 600;
  margin-bottom: 1rem;
  text-transform: uppercase;
  letter-spacing: 0.5px;
}

.chart-header {
  text-align: center;
  margin-bottom: 2rem;
}

.chart-title {
  font-size: 1.4rem;
  font-weight: 600;
  margin-bottom: 0.5rem;
}

.chart-subtitle {
  color: var(--text-secondary);
  font-size: 0.95rem;
}

.chart-container {
  display: flex;
  justify-content: center;
  margin-bottom: 2rem;
  position: relative;
}

.pie-chart {
  width: 220px;
  height: 220px;
  filter: drop-shadow(0 4px 8px rgba(0, 0, 0, 0.3));
}

/* Legend */
.legend {
  display: flex;
  flex-direction: column;
  gap: 0.75rem;
}

.legend-item {
  display: flex;
  align-items: center;
  gap: 1rem;
  padding: 0.75rem;
  background: var(--bg-tertiary);
  border-radius: 10px;
  transition: var(--transition);
  cursor: pointer;
  border: 2px solid transparent;
}

.legend-item:hover {
  background: #333333;
  transform: translateX(5px);
}

.legend-item.highlighted {
  background: rgba(59, 130, 246, 0.1);
  border-color: var(--accent-info);
  transform: translateX(8px);
}

.legend-color {
  width: 18px;
  height: 18px;
  border-radius: 50%;
  flex-shrink: 0;
  transition: var(--transition);
  box-shadow: 0 2px 4px rgba(0, 0, 0, 0.3);
}

.legend-item.highlighted .legend-color {
  transform: scale(1.2);
  box-shadow: 0 0 15px currentColor;
}

.legend-text {
  flex: 1;
  display: flex;
  justify-content: space-between;
  align-items: center;
}

.legend-label {
  font-weight: 500;
}

.legend-value {
  color: var(--text-secondary);
  font-size: 0.9rem;
  font-weight: 600;
}

.legend-percentage {
  color: var(--text-muted);
  font-size: 0.8rem;
  margin-left: 0.5rem;
}

/* Tooltip */
.tooltip {
  position: absolute;
  background: rgba(0, 0, 0, 0.9);
  color: white;
  padding: 0.5rem 1rem;
  border-radius: 8px;
  font-size: 0.9rem;
  pointer-events: none;
  z-index: 1000;
  opacity: 0;
  transition: opacity 0.2s ease;
  backdrop-filter: blur(10px);
  border: 1px solid rgba(255, 255, 255, 0.2);
}

.tooltip.visible {
  opacity: 1;
}

/* Footer */
footer {
  text-align: center;
  padding: 2rem 0;
  border-top: 1px solid var(--border-color);
  color: var(--text-muted);
  margin-top: 3rem;
  opacity: 0;
  animation: fadeIn 0.8s ease-out 1s forwards;
}

/* Error State */
.error {
  background: rgba(239, 68, 68, 0.1);
  border: 1px solid var(--accent-danger);
  color: var(--accent-danger);
  padding: 2rem;
  border-radius: 12px;
  text-align: center;
  margin: 2rem 0;
}

/* Animations */
@keyframes spin {
  0% { transform: rotate(0deg); }
  100% { transform: rotate(360deg); }
}

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

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

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

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

@keyframes gradientShift {
  0%, 100% { background-position: 0% 50%; }
  50% { background-position: 100% 50%; }
}

@keyframes drawPie {
  from {
    stroke-dasharray: 0 1000;
  }
  to {
    stroke-dasharray: var(--dash-array) 1000;
  }
}

/* Mobile Responsiveness */
@media (max-width: 768px) {
  .container {
    padding: 1rem 0.5rem;
  }

  header h1 {
    font-size: 2.5rem;
  }

  .controls {
    flex-direction: column;
    gap: 1rem;
    align-items: stretch;
  }

  .filter-group {
    justify-content: center;
  }

  .view-toggle {
    justify-content: center;
  }

  .charts-grid {
    grid-template-columns: 1fr;
    gap: 1.5rem;
  }

  .chart-card {
    padding: 1.5rem;
  }

  .pie-chart {
    width: 200px;
    height: 200px;
  }

  .stats-overview {
    grid-template-columns: repeat(3, 1fr);
    gap: 0.75rem;
  }
}

@media (max-width: 480px) {
  header h1 {
    font-size: 2rem;
  }

  .subtitle {
    font-size: 1rem;
  }

  .pie-chart {
    width: 180px;
    height: 180px;
  }

  .chart-title {
    font-size: 1.2rem;
  }

  .stats-overview {
    grid-template-columns: 1fr;
    gap: 0.75rem;
  }

  .stat-card {
    padding: 1rem;
  }
}

/* Hidden class for filtering */
.hidden {
  display: none !important;
}