:root {
  --primary-color: #2a6db0;
  --secondary-color: #f5f7fa;
  --accent-color: #e1e8ed;
  --text-color: #222;
  --text-muted: #666;
  --font-base: 'system-ui', sans-serif;
  --radius-md: 6px;
  --shadow-sm: 0 1px 3px rgba(0,0,0,0.1);
  --shadow-md: 0 2px 6px rgba(0,0,0,0.15);
  --spacing-xs: 0.25rem;
  --spacing-sm: 0.5rem;
  --spacing-md: 1rem;
  --spacing-lg: 1.5rem;
  --breakpoint-tablet: 768px;
}

/* ================================ */
/* Section: Filter Controls         */
/* ================================ */
.filter-controls,
.toolbar {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: var(--spacing-sm);
  background-color: var(--secondary-color);
  padding: var(--spacing-md);
  border-radius: var(--radius-md);
  box-shadow: var(--shadow-sm);
  font-family: var(--font-base);
}

.filter-controls select,
.filter-controls button,
.toolbar select,
.toolbar button {
  padding: var(--spacing-sm) var(--spacing-md);
  border: 1px solid var(--accent-color);
  border-radius: var(--radius-md);
  background-color: #fff;
  color: var(--text-color);
  cursor: pointer;
  transition: background-color 0.2s ease, box-shadow 0.2s ease;
}

.filter-controls button:hover,
.toolbar button:hover {
  background-color: var(--primary-color);
  color: #fff;
}

/* ================================ */
/* Section: Summary Cards             */
/* ================================ */
.summary-cards,
.grid {
  display: grid;
  gap: var(--spacing-md);
  grid-template-columns: repeat(auto-fit, minmax(220px, 1fr));
  margin-top: var(--spacing-md);
}

.summary-cards__card,
.grid__card {
  background-color: #fff;
  padding: var(--spacing-lg);
  border-radius: var(--radius-md);
  box-shadow: var(--shadow-md);
  text-align: center;
  font-family: var(--font-base);
}

.summary-cards__card h3,
.grid__card h3 {
  font-size: 1.1rem;
  color: var(--text-color);
  margin-bottom: var(--spacing-sm);
}

.summary-cards__card p,
.grid__card p {
  font-size: 0.9rem;
  color: var(--text-muted);
  margin: 0;
}

/* ================================ */
/* Section: Chart Style               */
/* ================================ */
.chart-container,
.chart-style {
  position: relative;
  width: 100%;
  min-height: 300px;
  background-color: #fff;
  border-radius: var(--radius-md);
  padding: var(--spacing-md);
  box-shadow: var(--shadow-md);
  overflow: hidden;
}

.chart-container canvas,
.chart-style canvas {
  width: 100%;
  height: 100%;
  display: block;
}

/* Responsive adjustments */
@media (min-width: var(--breakpoint-tablet)) {
  .filter-controls,
  .toolbar {
    justify-content: space-between;
  }
} 

/* Footer for copyright reference */
footer {
  text-align: center;
  font-size: 0.85rem;
  color: var(--text-muted);
  padding: var(--spacing-md);
}

footer::after {
  content: '© 2026 Donau2Space.de';
  display: block;
  margin-top: var(--spacing-xs);
}