:root {
  --primary: #2b6cb0;
  --secondary: #4a5568;
  --background: #f7fafc;
  --card-bg: #ffffff;
  --border-color: #e2e8f0;
  --text-color: #1a202c;
  --text-muted: #718096;
  --spacing-xs: 0.25rem;
  --spacing-sm: 0.5rem;
  --spacing-md: 1rem;
  --spacing-lg: 1.5rem;
  --border-radius: 0.5rem;
  --transition-fast: 0.15s ease-in-out;
  --font-base: 'system-ui', sans-serif;
}

/* ===============================================
   Filter Panel Styles
   =============================================== */
.filter-panel {
  display: flex;
  flex-wrap: wrap;
  gap: var(--spacing-md);
  background-color: var(--card-bg);
  border: 1px solid var(--border-color);
  border-radius: var(--border-radius);
  padding: var(--spacing-md);
  box-shadow: 0 1px 3px rgba(0, 0, 0, 0.05);
}

.filter-item {
  display: flex;
  flex-direction: column;
  gap: var(--spacing-xs);
  min-width: 160px;
}

.filter-item label {
  font-size: 0.875rem;
  font-weight: 600;
  color: var(--text-muted);
}

.filter-item select,
.filter-item input {
  padding: var(--spacing-sm);
  border: 1px solid var(--border-color);
  border-radius: var(--border-radius);
  background-color: var(--background);
  font-family: var(--font-base);
  color: var(--text-color);
  transition: border-color var(--transition-fast), box-shadow var(--transition-fast);
}

.filter-item select:focus,
.filter-item input:focus {
  border-color: var(--primary);
  box-shadow: 0 0 0 2px rgba(43, 108, 176, 0.2);
  outline: none;
}

.run-selector {
  font-size: 0.9rem;
  cursor: pointer;
}

.run-selector:hover,
.run-selector:focus {
  background-color: rgba(43, 108, 176, 0.05);
  border-color: var(--primary);
}

/* ===============================================
   Chart Panel Styles
   =============================================== */
.chart-panel {
  background-color: var(--card-bg);
  border: 1px solid var(--border-color);
  border-radius: var(--border-radius);
  padding: var(--spacing-lg);
  margin-top: var(--spacing-lg);
  box-shadow: 0 2px 4px rgba(0, 0, 0, 0.05);
}

.results-chart {
  width: 100%;
  height: 400px;
  display: block;
  border-radius: var(--border-radius);
  background-color: var(--background);
  overflow: hidden;
}

.results-chart canvas,
.results-chart svg {
  width: 100%;
  height: 100%;
}

/* ===============================================
   Statistics Cards
   =============================================== */
.overview-section {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(220px, 1fr));
  gap: var(--spacing-md);
  margin-top: var(--spacing-lg);
}

.stat-card {
  background-color: var(--card-bg);
  border: 1px solid var(--border-color);
  border-radius: var(--border-radius);
  padding: var(--spacing-md);
  display: flex;
  flex-direction: column;
  gap: var(--spacing-sm);
  box-shadow: 0 1px 3px rgba(0, 0, 0, 0.05);
  transition: transform var(--transition-fast), box-shadow var(--transition-fast);
}

.stat-card:hover {
  transform: translateY(-2px);
  box-shadow: 0 3px 6px rgba(0, 0, 0, 0.1);
}

.stat-card h3 {
  font-size: 1rem;
  font-weight: 600;
  color: var(--text-color);
}

.stat-card p {
  font-size: 0.875rem;
  color: var(--text-muted);
}

@media (min-width: 640px) {
  .results-chart {
    height: 500px;
  }
  .filter-panel {
    flex-wrap: nowrap;
  }
}

@media (min-width: 1024px) {
  .results-chart {
    height: 600px;
  }
}