/* Base Styles */
:root {
  --primary-color: #3a86ff;
  --secondary-color: #8338ec;
  --accent-color: #ff006e;
  --background-color: #f8f9fa;
  --card-background: #ffffff;
  --text-primary: #333333;
  --text-secondary: #666666;
  --shadow: 0 4px 6px rgba(0, 0, 0, 0.1);
  --transition: all 0.3s ease;
  --spacing-sm: 0.5rem;
  --spacing-md: 1rem;
  --spacing-lg: 2rem;
  --border-radius: 8px;
}

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

body {
  font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
  line-height: 1.6;
  color: var(--text-primary);
  background-color: var(--background-color);
  min-height: 100vh;
  display: flex;
  flex-direction: column;
}

/* Typography */
h1, h2, h3, h4, h5, h6 {
  margin-bottom: var(--spacing-md);
  font-weight: 600;
  line-height: 1.3;
}

h1 {
  font-size: 2rem;
}

h2 {
  font-size: 1.5rem;
  color: var(--text-primary);
}

h3 {
  font-size: 1.25rem;
  color: var(--text-primary);
}

p {
  margin-bottom: var(--spacing-md);
}

/* Layout Components */
header {
  background: linear-gradient(135deg, var(--primary-color), var(--secondary-color));
  color: white;
  padding: var(--spacing-lg);
  text-align: center;
  position: sticky;
  top: 0;
  z-index: 100;
  box-shadow: var(--shadow);
}

main {
  flex: 1;
  padding: var(--spacing-lg);
  max-width: 1200px;
  margin: 0 auto;
  width: 100%;
}

footer {
  background-color: var(--text-primary);
  color: white;
  text-align: center;
  padding: var(--spacing-md);
  margin-top: auto;
}

/* Cards Container */
.cards-container {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(300px, 1fr));
  gap: var(--spacing-lg);
  margin-top: var(--spacing-lg);
}

/* Card Styles */
.card {
  background-color: var(--card-background);
  border-radius: var(--border-radius);
  box-shadow: var(--shadow);
  overflow: hidden;
  transition: var(--transition);
  display: flex;
  flex-direction: column;
  height: 100%;
}

.card:hover {
  transform: translateY(-5px);
  box-shadow: 0 10px 20px rgba(0, 0, 0, 0.15);
}

.card-header {
  padding: var(--spacing-md);
  border-bottom: 1px solid #eee;
}

.card-header h2 {
  margin-bottom: var(--spacing-sm);
  color: var(--primary-color);
}

.card-body {
  padding: var(--spacing-md);
  flex: 1;
}

.card-description {
  margin-bottom: var(--spacing-md);
  color: var(--text-secondary);
}

.card-stats {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: var(--spacing-sm);
  margin-bottom: var(--spacing-md);
}

.stat-item {
  background-color: #f0f4f8;
  padding: var(--spacing-sm);
  border-radius: var(--border-radius);
  text-align: center;
}

.stat-value {
  font-size: 1.25rem;
  font-weight: bold;
  color: var(--primary-color);
}

.stat-value-secondary {
  font-size: 1.25rem;
  font-weight: bold;
  color: var(--accent-color);
}

.stat-label {
  font-size: 0.875rem;
  color: var(--text-secondary);
}

.card-image {
  display: block;
  margin: 0 auto;
  width: 50%;
  height: 150px;
  object-fit: contain; 
  border-bottom: 1px solid #eee;
  background-color: #ffffff;
}

.card-chart {
  margin-top: var(--spacing-md);
  height: 230px;
  width: 100%;
}

/* Chart Styles */
.bar {
  fill: var(--primary-color);
  transition: var(--transition);
}

.bar:hover {
  fill: var(--accent-color);
}

.axis text {
  font-size: 12px;
  fill: var(--text-secondary);
}

.axis-label {
  font-size: 14px;
  fill: var(--text-primary);
  font-weight: bold;
}

.chart-title {
  font-size: 16px;
  fill: var(--text-primary);
  font-weight: bold;
  text-anchor: middle;
}

/* Loading State */
.loading-container {
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  height: 300px;
}

.loading-spinner {
  width: 50px;
  height: 50px;
  border: 5px solid rgba(0, 0, 0, 0.1);
  border-radius: 50%;
  border-top-color: var(--primary-color);
  animation: spin 1s ease-in-out infinite;
  margin-bottom: var(--spacing-md);
}

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

/* Error State */
.error-container {
  text-align: center;
  padding: var(--spacing-lg);
  background-color: #fff5f5;
  border: 1px solid #fed7d7;
  border-radius: var(--border-radius);
  margin: var(--spacing-lg) 0;
}

#retry-button {
  background-color: var(--primary-color);
  color: white;
  border: none;
  padding: var(--spacing-sm) var(--spacing-md);
  border-radius: var(--border-radius);
  cursor: pointer;
  transition: var(--transition);
}

#retry-button:hover {
  background-color: var(--secondary-color);
}

/* Responsive Design */
@media (max-width: 768px) {
  .cards-container {
    grid-template-columns: 1fr;
  }
  
  header {
    padding: var(--spacing-md);
  }
  
  h1 {
    font-size: 1.5rem;
  }
  
  .card-stats {
    grid-template-columns: 1fr;
  }
}

/* Accessibility */
:focus {
  outline: 3px solid var(--primary-color);
  outline-offset: 2px;
}

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