:root {
  /* Light Theme Colors */
  --bg-primary: #ffffff;
  --bg-secondary: #f8fafc;
  --bg-tertiary: #f1f5f9;
  --text-primary: #1e293b;
  --text-secondary: #64748b;
  --text-muted: #94a3b8;
  --border-color: #e2e8f0;
  --shadow: 0 1px 3px rgba(0, 0, 0, 0.1);
  --shadow-lg: 0 10px 15px -3px rgba(0, 0, 0, 0.1);

  /* Status Colors */
  --success: #10b981;
  --success-bg: #d1fae5;
  --warning: #f59e0b;
  --warning-bg: #fef3c7;
  --error: #ef4444;
  --error-bg: #fee2e2;
  --info: #3b82f6;
  --info-bg: #dbeafe;

  /* Chart Colors */
  --chart-power: #10b981;
  --chart-voltage: #3b82f6;
  --chart-current: #f59e0b;

  /* Spacing */
  --spacing-xs: 0.25rem;
  --spacing-sm: 0.5rem;
  --spacing-md: 1rem;
  --spacing-lg: 1.5rem;
  --spacing-xl: 2rem;

  /* Border Radius */
  --radius-sm: 0.375rem;
  --radius-md: 0.5rem;
  --radius-lg: 0.75rem;
}

[data-theme="dark"] {
  --bg-primary: #0f172a;
  --bg-secondary: #1e293b;
  --bg-tertiary: #334155;
  --text-primary: #f1f5f9;
  --text-secondary: #cbd5e1;
  --text-muted: #64748b;
  --border-color: #334155;
  --shadow: 0 1px 3px rgba(0, 0, 0, 0.3);
  --shadow-lg: 0 10px 15px -3px rgba(0, 0, 0, 0.3);
}

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

body {
  font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, Oxygen, Ubuntu, Cantarell, sans-serif;
  background-color: var(--bg-secondary);
  color: var(--text-primary);
  line-height: 1.5;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}

#app {
  min-height: 100vh;
  display: flex;
  flex-direction: column;
}

/* Navigation */
.main-nav {
  background-color: var(--bg-primary);
  border-bottom: 1px solid var(--border-color);
  padding: var(--spacing-md) var(--spacing-lg);
  display: flex;
  justify-content: space-between;
  align-items: center;
  position: sticky;
  top: 0;
  z-index: 100;
  box-shadow: var(--shadow);
}

.nav-tabs {
  display: flex;
  gap: var(--spacing-sm);
}

.nav-tab {
  padding: var(--spacing-sm) var(--spacing-md);
  background: transparent;
  border: none;
  color: var(--text-secondary);
  cursor: pointer;
  border-radius: var(--radius-md);
  font-weight: 500;
  transition: all 0.2s ease;
}

.nav-tab:hover {
  background-color: var(--bg-tertiary);
  color: var(--text-primary);
}

.nav-tab.active {
  background-color: var(--bg-tertiary);
  color: var(--text-primary);
}

.nav-controls {
  display: flex;
  align-items: center;
  gap: var(--spacing-md);
}

.btn-icon {
  width: 40px;
  height: 40px;
  border: none;
  background: transparent;
  cursor: pointer;
  border-radius: var(--radius-md);
  font-size: 1.25rem;
  display: flex;
  align-items: center;
  justify-content: center;
  transition: background-color 0.2s ease;
}

.btn-icon:hover {
  background-color: var(--bg-tertiary);
}

.mode-toggle {
  display: flex;
  background-color: var(--bg-tertiary);
  border-radius: var(--radius-md);
  padding: var(--spacing-xs);
}

.mode-btn {
  padding: var(--spacing-xs) var(--spacing-md);
  background: transparent;
  border: none;
  color: var(--text-secondary);
  cursor: pointer;
  border-radius: var(--radius-sm);
  font-weight: 500;
  transition: all 0.2s ease;
}

.mode-btn:hover {
  color: var(--text-primary);
}

.mode-btn.active {
  background-color: var(--bg-primary);
  color: var(--text-primary);
  box-shadow: var(--shadow);
}

/* Main Content */
.main-content {
  flex: 1;
  padding: var(--spacing-lg);
  max-width: 1400px;
  margin: 0 auto;
  width: 100%;
}

.connection-status {
  display: inline-flex;
  align-items: center;
  gap: var(--spacing-sm);
  padding: var(--spacing-sm) var(--spacing-md);
  border-radius: var(--radius-md);
  font-size: 0.875rem;
  font-weight: 500;
  margin-bottom: var(--spacing-md);
}

.connection-status::before {
  content: '';
  width: 8px;
  height: 8px;
  border-radius: 50%;
  background-color: var(--success);
  animation: pulse 2s infinite;
}

.connection-status.connected {
  background-color: var(--success-bg);
  color: var(--success);
}

.connection-status.disconnected {
  background-color: var(--error-bg);
  color: var(--error);
}

.connection-status.disconnected::before {
  background-color: var(--error);
  animation: none;
}

@keyframes pulse {
  0%, 100% {
    opacity: 1;
  }
  50% {
    opacity: 0.5;
  }
}

/* Screens */
.screen {
  display: none;
}

.screen:not(.hidden) {
  display: block;
}

.screen.hidden {
  display: none;
}

/* Metrics Grid */
.metrics-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
  gap: var(--spacing-md);
  margin-bottom: var(--spacing-lg);
}

.metric-card {
  background-color: var(--bg-primary);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-lg);
  padding: var(--spacing-md);
  box-shadow: var(--shadow);
}

.metric-label {
  font-size: 0.875rem;
  color: var(--text-secondary);
  margin-bottom: var(--spacing-xs);
}

.metric-value {
  font-size: 1.75rem;
  font-weight: 700;
  color: var(--text-primary);
}

.metric-unit {
  font-size: 0.875rem;
  color: var(--text-muted);
  margin-left: var(--spacing-xs);
}

.metric-trend {
  display: inline-flex;
  align-items: center;
  gap: var(--spacing-xs);
  font-size: 0.75rem;
  font-weight: 500;
  margin-top: var(--spacing-sm);
  padding: var(--spacing-xs) var(--spacing-sm);
  border-radius: var(--radius-sm);
}

.metric-trend.up {
  color: var(--success);
  background-color: var(--success-bg);
}

.metric-trend.down {
  color: var(--error);
  background-color: var(--error-bg);
}

/* Chart Container */
.chart-container {
  background-color: var(--bg-primary);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-lg);
  padding: var(--spacing-md);
  margin-bottom: var(--spacing-lg);
  box-shadow: var(--shadow);
}

.chart-header {
  display: flex;
  justify-content: space-between;
  align-items: center;
  margin-bottom: var(--spacing-md);
  flex-wrap: wrap;
  gap: var(--spacing-md);
}

.chart-header h3 {
  font-size: 1rem;
  font-weight: 600;
  color: var(--text-primary);
}

.metric-select {
  padding: var(--spacing-xs) var(--spacing-md);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-md);
  background-color: var(--bg-secondary);
  color: var(--text-primary);
  font-size: 0.875rem;
  cursor: pointer;
}

.chart-controls {
  display: flex;
  gap: var(--spacing-xs);
  background-color: var(--bg-tertiary);
  padding: var(--spacing-xs);
  border-radius: var(--radius-md);
}

.chart-metric-btn {
  padding: var(--spacing-xs) var(--spacing-md);
  background: transparent;
  border: none;
  color: var(--text-secondary);
  cursor: pointer;
  border-radius: var(--radius-sm);
  font-size: 0.875rem;
  font-weight: 500;
  transition: all 0.2s ease;
}

.chart-metric-btn:hover {
  color: var(--text-primary);
}

.chart-metric-btn.active {
  background-color: var(--bg-primary);
  color: var(--text-primary);
  box-shadow: var(--shadow);
}

.chart {
  height: 300px;
  width: 100%;
}

/* Devices Grid */
.devices-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(280px, 1fr));
  gap: var(--spacing-md);
}

.device-card {
  background-color: var(--bg-primary);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-lg);
  padding: var(--spacing-md);
  box-shadow: var(--shadow);
  cursor: pointer;
  transition: all 0.2s ease;
}

.device-card:hover {
  box-shadow: var(--shadow-lg);
  transform: translateY(-2px);
}

.device-card-header {
  display: flex;
  justify-content: space-between;
  align-items: start;
  margin-bottom: var(--spacing-md);
}

.device-card-name {
  font-weight: 600;
  color: var(--text-primary);
  margin-bottom: var(--spacing-xs);
}

.device-card-type {
  font-size: 0.75rem;
  color: var(--text-muted);
  text-transform: uppercase;
  letter-spacing: 0.05em;
}

.device-card-status {
  width: 12px;
  height: 12px;
  border-radius: 50%;
  flex-shrink: 0;
}

.device-card-status.online {
  background-color: var(--success);
  box-shadow: 0 0 0 2px var(--success-bg);
}

.device-card-status.offline {
  background-color: var(--error);
  box-shadow: 0 0 0 2px var(--error-bg);
}

.device-card-status.warning {
  background-color: var(--warning);
  box-shadow: 0 0 0 2px var(--warning-bg);
}

.device-card-metrics {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: var(--spacing-sm);
}

.device-card-metric {
  text-align: center;
}

.device-card-metric-label {
  font-size: 0.75rem;
  color: var(--text-secondary);
  margin-bottom: var(--spacing-xs);
}

.device-card-metric-value {
  font-size: 1rem;
  font-weight: 600;
  color: var(--text-primary);
}

/* Device Screen */
.device-header {
  display: flex;
  justify-content: space-between;
  align-items: center;
  margin-bottom: var(--spacing-lg);
}

.device-header h2 {
  font-size: 1.5rem;
  font-weight: 700;
  color: var(--text-primary);
}

.device-status {
  padding: var(--spacing-xs) var(--spacing-md);
  border-radius: var(--radius-md);
  font-size: 0.875rem;
  font-weight: 500;
}

.device-status.online {
  background-color: var(--success-bg);
  color: var(--success);
}

.device-status.offline {
  background-color: var(--error-bg);
  color: var(--error);
}

.device-status.warning {
  background-color: var(--warning-bg);
  color: var(--warning);
}

/* History Controls */
.history-controls {
  background-color: var(--bg-primary);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-lg);
  padding: var(--spacing-md);
  margin-bottom: var(--spacing-lg);
  box-shadow: var(--shadow);
}

.range-selector {
  display: flex;
  gap: var(--spacing-xs);
  justify-content: center;
  flex-wrap: wrap;
}

.range-btn {
  padding: var(--spacing-xs) var(--spacing-md);
  background: transparent;
  border: 1px solid var(--border-color);
  color: var(--text-secondary);
  cursor: pointer;
  border-radius: var(--radius-md);
  font-size: 0.875rem;
  font-weight: 500;
  transition: all 0.2s ease;
}

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

.range-btn.active {
  background-color: var(--info-bg);
  border-color: var(--info);
  color: var(--info);
}

/* Responsive Design */
@media (max-width: 768px) {
  .main-nav {
    flex-direction: column;
    gap: var(--spacing-md);
  }

  .nav-controls {
    width: 100%;
    justify-content: space-between;
  }

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

  .chart-header {
    flex-direction: column;
    align-items: flex-start;
  }

  .chart {
    height: 200px;
  }

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

  .device-card-metrics {
    grid-template-columns: 1fr;
  }
}

/* uPlot Customization */
.u-tooltip {
  background-color: var(--bg-primary) !important;
  border: 1px solid var(--border-color) !important;
  border-radius: var(--radius-md) !important;
  box-shadow: var(--shadow-lg) !important;
  color: var(--text-primary) !important;
}

.u-series > * {
  stroke-width: 2px !important;
}