:root {
  /* Energy source colors */
  --color-hydro: #2196F3;
  --color-wind: #009688;
  --color-wind-offshore: #00695C;
  --color-solar: #FFC107;
  --color-nuclear: #9C27B0;
  --color-thermal: #795548;
  --color-storage: #00BCD4;
  --color-other: #9E9E9E;

  /* Price colors */
  --color-upreg: #1565C0;
  --color-downreg: #E65100;

  /* UI colors */
  --bg-primary: #0a0e17;
  --bg-surface: #121826;
  --bg-card: #1a2035;
  --border: #2a3045;
  --text-primary: #e8eaf0;
  --text-secondary: #8892a8;
  --accent: #4fc3f7;
  --color-consumption: #ffffff;
  --color-surplus: #4caf50;
  --color-deficit: #ef5350;

  /* Typography */
  --font-display: "JetBrains Mono", monospace;
  --font-body: "DM Sans", sans-serif;

  /* Spacing */
  --space-xs: 4px;
  --space-sm: 8px;
  --space-md: 16px;
  --space-lg: 24px;
  --space-xl: 32px;

  --radius: 6px;
}

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

html {
  font-size: 16px;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}

body {
  font-family: var(--font-body);
  background: var(--bg-primary);
  color: var(--text-primary);
  min-height: 100vh;
}

/* Scrollbar */
::-webkit-scrollbar {
  width: 8px;
}
::-webkit-scrollbar-track {
  background: var(--bg-primary);
}
::-webkit-scrollbar-thumb {
  background: var(--border);
  border-radius: 4px;
}

/* ─── Dashboard Layout ─── */

.dashboard {
  max-width: 1200px;
  margin: 0 auto;
  padding: var(--space-lg);
  display: flex;
  flex-direction: column;
  gap: var(--space-lg);
}

/* ─── Header ─── */

.header {
  display: flex;
  align-items: baseline;
  gap: var(--space-md);
}

.header h1 {
  font-family: var(--font-display);
  font-size: 1.25rem;
  font-weight: 700;
  letter-spacing: 0.08em;
  color: var(--text-primary);
}

/* ─── Controls ─── */

.controls {
  display: flex;
  align-items: center;
  gap: var(--space-sm);
  flex-wrap: wrap;
}

.controls select,
.controls input[type="date"] {
  font-family: var(--font-display);
  font-size: 0.8125rem;
  background: var(--bg-surface);
  color: var(--text-primary);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: var(--space-sm) var(--space-md);
  outline: none;
  transition: border-color 0.15s;
}

.controls select:focus,
.controls input[type="date"]:focus {
  border-color: var(--accent);
}

.controls select {
  min-width: 80px;
  cursor: pointer;
}

.controls input[type="date"] {
  min-width: 150px;
}

/* Date input calendar icon color (webkit) */
.controls input[type="date"]::-webkit-calendar-picker-indicator {
  filter: invert(0.7);
  cursor: pointer;
}

#go-btn {
  font-family: var(--font-display);
  font-size: 0.8125rem;
  font-weight: 600;
  letter-spacing: 0.08em;
  background: var(--accent);
  color: var(--bg-primary);
  border: none;
  border-radius: var(--radius);
  padding: var(--space-sm) var(--space-lg);
  cursor: pointer;
  transition: opacity 0.15s;
}

#go-btn:hover {
  opacity: 0.85;
}

#go-btn:disabled {
  opacity: 0.4;
  cursor: not-allowed;
}

/* ─── Error Banner ─── */

.error-message {
  font-family: var(--font-body);
  font-size: 0.875rem;
  background: rgba(239, 83, 80, 0.12);
  border: 1px solid rgba(239, 83, 80, 0.3);
  color: #ef5350;
  border-radius: var(--radius);
  padding: var(--space-sm) var(--space-md);
  cursor: pointer;
}

/* ─── Empty State ─── */

.empty-state {
  font-family: var(--font-body);
  font-size: 0.9375rem;
  color: var(--text-secondary);
  text-align: center;
  padding: var(--space-xl) var(--space-md);
}

/* ─── Stats Grid ─── */

.stats-grid {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: var(--space-md);
}

.stat-card {
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: var(--space-md) var(--space-md) var(--space-md) var(--space-lg);
  position: relative;
  overflow: hidden;
}

.stat-card::before {
  content: "";
  position: absolute;
  left: 0;
  top: 0;
  bottom: 0;
  width: 3px;
  background: var(--accent-color, var(--accent));
}

.stat-card .stat-label {
  font-family: var(--font-display);
  font-size: 0.625rem;
  font-weight: 600;
  letter-spacing: 0.1em;
  color: var(--text-secondary);
  text-transform: uppercase;
  margin-bottom: var(--space-xs);
}

.stat-card .stat-value {
  font-family: var(--font-display);
  font-size: 1.375rem;
  font-weight: 700;
  color: var(--text-primary);
  line-height: 1.2;
}

.stat-card .stat-detail {
  font-family: var(--font-body);
  font-size: 0.75rem;
  color: var(--text-secondary);
  margin-top: var(--space-xs);
}

/* ─── Chart Containers ─── */

.chart-container {
  background: var(--bg-surface);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: var(--space-lg);
}

.chart-container h2 {
  font-family: var(--font-display);
  font-size: 0.6875rem;
  font-weight: 600;
  letter-spacing: 0.1em;
  color: var(--text-secondary);
  text-transform: uppercase;
  margin-bottom: var(--space-md);
}

.chart-wrapper {
  position: relative;
  height: 400px;
}

.chart-container:last-child .chart-wrapper {
  height: 250px;
}

/* ─── Loading Overlay ─── */

.loading-overlay {
  position: absolute;
  inset: 0;
  display: flex;
  align-items: center;
  justify-content: center;
  background: rgba(10, 14, 23, 0.7);
  border-radius: var(--radius);
  z-index: 10;
}

.loading-overlay[hidden] {
  display: none;
}

.spinner {
  width: 32px;
  height: 32px;
  border: 3px solid var(--border);
  border-top-color: var(--accent);
  border-radius: 50%;
  animation: spin 0.8s linear infinite;
}

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

/* ─── Responsive ─── */

@media (max-width: 1023px) {
  .stats-grid {
    grid-template-columns: repeat(2, 1fr);
  }

  .chart-wrapper {
    height: 350px;
  }

  .chart-container:last-child .chart-wrapper {
    height: 220px;
  }
}

@media (max-width: 767px) {
  .dashboard {
    padding: var(--space-md);
  }

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

  .controls select,
  .controls input[type="date"],
  #go-btn {
    width: 100%;
  }

  .stats-grid {
    grid-template-columns: 1fr;
  }

  .chart-wrapper {
    height: 280px;
  }

  .chart-container:last-child .chart-wrapper {
    height: 200px;
  }
}