/* ========================================
   CSS CUSTOM PROPERTIES (Variables)
   ======================================== */
:root {
  /* Color System */
  --color-bg-primary: #1a1d29;
  --color-bg-secondary: #252936;
  --color-bg-tertiary: #2f3441;
  --color-bg-hover: #353947;
  
  --color-text-primary: #ffffff;
  --color-text-secondary: #b4b9c8;
  --color-text-tertiary: #8b92a7;
  
  --color-accent-primary: #3b82f6;
  --color-accent-hover: #2563eb;
  --color-accent-light: #60a5fa;
  
  --color-success: #10b981;
  --color-success-dark: #059669;
  --color-warning: #f59e0b;
  --color-danger: #ef4444;
  --color-danger-dark: #dc2626;
  
  --color-border: rgba(255, 255, 255, 0.1);
  --color-border-light: rgba(255, 255, 255, 0.05);
  
  /* Spacing System (8px base) */
  --space-xs: 0.25rem;  /* 4px */
  --space-sm: 0.5rem;   /* 8px */
  --space-md: 1rem;     /* 16px */
  --space-lg: 1.5rem;   /* 24px */
  --space-xl: 2rem;     /* 32px */
  --space-2xl: 3rem;    /* 48px */
  
  /* Typography */
  --font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', 'Roboto', 'Oxygen', 'Ubuntu', 'Cantarell', sans-serif;
  --font-size-xs: 0.75rem;   /* 12px */
  --font-size-sm: 0.875rem;  /* 14px */
  --font-size-md: 1rem;      /* 16px */
  --font-size-lg: 1.125rem;  /* 18px */
  --font-size-xl: 1.25rem;   /* 20px */
  --font-size-2xl: 1.5rem;   /* 24px */
  --font-size-3xl: 2rem;     /* 32px */
  
  /* Border Radius */
  --radius-sm: 0.375rem;  /* 6px */
  --radius-md: 0.5rem;    /* 8px */
  --radius-lg: 0.75rem;   /* 12px */
  --radius-xl: 1rem;      /* 16px */
  
  /* Shadows */
  --shadow-sm: 0 1px 2px 0 rgba(0, 0, 0, 0.3);
  --shadow-md: 0 4px 6px -1px rgba(0, 0, 0, 0.4), 0 2px 4px -1px rgba(0, 0, 0, 0.3);
  --shadow-lg: 0 10px 15px -3px rgba(0, 0, 0, 0.4), 0 4px 6px -2px rgba(0, 0, 0, 0.3);
  
  /* Transitions */
  --transition-fast: 150ms ease-in-out;
  --transition-base: 200ms ease-in-out;
  --transition-slow: 300ms ease-in-out;
  
  /* Layout */
  --max-width: 1400px;
  --header-height: 80px;
}

/* ========================================
   RESET & BASE STYLES
   ======================================== */
* {
  box-sizing: border-box;
  margin: 0;
  padding: 0;
}

body {
  font-family: var(--font-family);
  font-size: var(--font-size-md);
  line-height: 1.6;
  background: var(--color-bg-primary);
  color: var(--color-text-primary);
  min-height: 100vh;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
  /* Safe area for notched devices */
  padding-left: env(safe-area-inset-left);
  padding-right: env(safe-area-inset-right);
  /* Better touch behavior */
  -webkit-tap-highlight-color: rgba(59, 130, 246, 0.2);
  touch-action: manipulation;
}

/* ========================================
   UTILITY CLASSES
   ======================================== */
.hidden {
  display: none !important;
}

/* ========================================
   APP HEADER
   ======================================== */
.app-header {
  background: var(--color-bg-secondary);
  border-bottom: 1px solid var(--color-border);
  padding: var(--space-lg) var(--space-xl);
  box-shadow: var(--shadow-md);
  position: sticky;
  top: 0;
  z-index: 100;
}

.app-header__container {
  max-width: var(--max-width);
  margin: 0 auto;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: var(--space-lg);
  flex-wrap: wrap;
}

.app-header__brand {
  display: flex;
  flex-direction: column;
  gap: var(--space-xs);
}

.app-header__title {
  font-size: var(--font-size-2xl);
  font-weight: 700;
  color: var(--color-text-primary);
  margin: 0;
}

.app-header__subtitle {
  font-size: var(--font-size-sm);
  color: var(--color-text-secondary);
}

.app-header__actions {
  display: flex;
  gap: var(--space-md);
}

.app-header__status {
  display: flex;
  align-items: center;
  gap: var(--space-lg);
  flex-wrap: wrap;
}

.app-header__timestamp {
  font-size: var(--font-size-sm);
  color: var(--color-text-tertiary);
}

/* Status Badge */
.status-badge {
  display: inline-flex;
  align-items: center;
  gap: var(--space-sm);
  padding: var(--space-sm) var(--space-md);
  background: var(--color-bg-tertiary);
  border-radius: var(--radius-lg);
  font-size: var(--font-size-sm);
  font-weight: 500;
}

.status-badge__indicator {
  width: 8px;
  height: 8px;
  border-radius: 50%;
  background: var(--color-text-tertiary);
}

.status-badge--connected .status-badge__indicator {
  background: var(--color-success);
  animation: pulse 2s cubic-bezier(0.4, 0, 0.6, 1) infinite;
}

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

/* ========================================
   BUTTONS
   ======================================== */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: var(--space-sm);
  padding: var(--space-sm) var(--space-lg);
  font-size: var(--font-size-md);
  font-weight: 600;
  font-family: inherit;
  border: none;
  border-radius: var(--radius-md);
  cursor: pointer;
  transition: all var(--transition-base);
  min-height: 44px;
  white-space: nowrap;
  /* Better touch targets */
  -webkit-tap-highlight-color: transparent;
  touch-action: manipulation;
  user-select: none;
}

.btn:hover {
  transform: translateY(-1px);
  box-shadow: var(--shadow-md);
}

.btn:active {
  transform: translateY(0);
}

.btn--primary {
  background: var(--color-accent-primary);
  color: white;
}

.btn--primary:hover {
  background: var(--color-accent-hover);
}

.btn--secondary {
  background: var(--color-bg-tertiary);
  color: var(--color-text-primary);
  border: 1px solid var(--color-border);
}

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

.btn__icon {
  font-size: var(--font-size-lg);
  line-height: 1;
}

/* ========================================
   VIEW NAVIGATION
   ======================================== */
.view-nav {
  background: var(--color-bg-secondary);
  border-bottom: 1px solid var(--color-border);
  padding: 0 var(--space-xl);
}

.view-nav__container {
  max-width: var(--max-width);
  margin: 0 auto;
  display: flex;
  gap: var(--space-sm);
}

.view-nav__btn {
  display: flex;
  align-items: center;
  gap: var(--space-sm);
  padding: var(--space-md) var(--space-lg);
  background: transparent;
  border: none;
  border-bottom: 2px solid transparent;
  color: var(--color-text-secondary);
  font-family: inherit;
  font-size: var(--font-size-md);
  font-weight: 500;
  cursor: pointer;
  transition: all var(--transition-base);
  /* Better touch */
  -webkit-tap-highlight-color: transparent;
  touch-action: manipulation;
  user-select: none;
}

.view-nav__btn:hover {
  color: var(--color-text-primary);
  background: var(--color-bg-hover);
}

.view-nav__btn--active {
  color: var(--color-accent-light);
  border-bottom-color: var(--color-accent-primary);
}

.view-nav__icon {
  font-size: var(--font-size-lg);
}

/* ========================================
   MAIN CONTENT
   ======================================== */
.app-main {
  max-width: var(--max-width);
  margin: 0 auto;
  padding: var(--space-xl);
}

/* ========================================
   DASHBOARD LAYOUT
   ======================================== */
.dashboard {
  display: flex;
  flex-direction: column;
  gap: var(--space-xl);
}

/* ========================================
   CARDS
   ======================================== */
.card {
  background: var(--color-bg-secondary);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-lg);
  box-shadow: var(--shadow-sm);
  overflow: hidden;
  transition: box-shadow var(--transition-base);
}

.card:hover {
  box-shadow: var(--shadow-md);
}

.card--highlight {
  border-color: var(--color-accent-primary);
  box-shadow: 0 0 0 1px var(--color-accent-primary);
}

.card--wide {
  grid-column: 1 / -1;
}

.card--span-2 {
  grid-column: span 2;
}

.card__header {
  padding: var(--space-lg);
  border-bottom: 1px solid var(--color-border-light);
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: var(--space-md);
}

.card__title {
  font-size: var(--font-size-lg);
  font-weight: 600;
  color: var(--color-text-primary);
  margin: 0;
}

.card__header-info {
  display: flex;
  gap: var(--space-lg);
}

.card__body {
  padding: var(--space-lg);
}

/* ========================================
   METRICS SECTION
   ======================================== */
.metrics__grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
  gap: var(--space-lg);
}

.metric {
  display: flex;
  flex-direction: column;
  gap: var(--space-xs);
}

.metric--large {
  padding-bottom: var(--space-md);
  border-bottom: 1px solid var(--color-border-light);
  margin-bottom: var(--space-md);
}

.metric__value {
  font-size: var(--font-size-2xl);
  font-weight: 700;
  color: var(--color-text-primary);
  line-height: 1.2;
}

.metric--large .metric__value {
  font-size: var(--font-size-3xl);
  color: var(--color-accent-light);
}

.metric__unit {
  font-size: 0.6em;
  font-weight: 600;
  color: var(--color-text-secondary);
  margin-left: var(--space-xs);
}

.metric__label {
  font-size: var(--font-size-sm);
  color: var(--color-text-secondary);
  text-transform: uppercase;
  letter-spacing: 0.05em;
  font-weight: 500;
}

.metric-row {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(100px, 1fr));
  gap: var(--space-lg);
}

/* Info Item (inline label-value pairs) */
.info-item {
  display: inline-flex;
  align-items: baseline;
  gap: var(--space-xs);
  font-size: var(--font-size-sm);
}

.info-item__label {
  color: var(--color-text-secondary);
  font-weight: 500;
}

.info-item__value {
  color: var(--color-text-primary);
  font-weight: 600;
}

.info-item__unit {
  color: var(--color-text-tertiary);
  font-size: 0.9em;
}

/* ========================================
   STATUS INDICATORS
   ======================================== */
.status-indicators {
  display: flex;
  flex-direction: column;
  gap: var(--space-md);
}

.status-indicator {
  display: flex;
}

.status-indicator__badge {
  display: inline-flex;
  align-items: center;
  gap: var(--space-sm);
  padding: var(--space-sm) var(--space-md);
  border-radius: var(--radius-md);
  font-size: var(--font-size-sm);
  font-weight: 600;
  transition: all var(--transition-base);
}

.status-indicator__badge--enabled {
  background: var(--color-success);
  color: white;
}

.status-indicator__badge--disabled {
  background: var(--color-bg-tertiary);
  color: var(--color-text-tertiary);
}

.status-indicator__icon {
  font-size: var(--font-size-md);
}

/* ========================================
   CELL VOLTAGES
   ======================================== */
.cells-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(200px, 1fr));
  gap: var(--space-lg);
}

.cell-item {
  display: flex;
  flex-direction: column;
  gap: var(--space-sm);
  padding: var(--space-md);
  background: var(--color-bg-tertiary);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-md);
  transition: all var(--transition-base);
  min-height: 80px;
  justify-content: center;
}

.cell-item:hover {
  border-color: var(--color-accent-primary);
  transform: translateY(-2px);
}

@media (hover: none) {
  .cell-item:hover {
    transform: none;
  }
}

.cell-item__label {
  font-size: var(--font-size-sm);
  color: var(--color-text-secondary);
  text-transform: uppercase;
  letter-spacing: 0.05em;
  font-weight: 500;
}

.cell-item__value {
  font-size: var(--font-size-xl);
  font-weight: 700;
  color: var(--color-text-primary);
}

.cell-item__unit {
  font-size: 0.7em;
  color: var(--color-text-secondary);
  margin-left: var(--space-xs);
}

.cell-item__indicator {
  margin-top: var(--space-xs);
}

.balance-indicator {
  font-size: var(--font-size-lg);
  color: var(--color-text-tertiary);
  transition: color var(--transition-base);
}

.balance-indicator--enabled {
  color: var(--color-success);
  animation: pulse 2s cubic-bezier(0.4, 0, 0.6, 1) infinite;
}

.balance-indicator--disabled {
  color: var(--color-bg-tertiary);
}

/* ========================================
   SECONDARY INFO GRID
   ======================================== */
.secondary-info__grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
  gap: var(--space-lg);
}

/* Info List */
.info-list {
  list-style: none;
  display: flex;
  flex-direction: column;
  gap: var(--space-md);
}

.info-list__item {
  display: flex;
  justify-content: space-between;
  align-items: center;
  padding-bottom: var(--space-sm);
  border-bottom: 1px solid var(--color-border-light);
}

.info-list__item:last-child {
  border-bottom: none;
  padding-bottom: 0;
}

.info-list__label {
  font-size: var(--font-size-sm);
  color: var(--color-text-secondary);
  font-weight: 500;
}

.info-list__value {
  font-size: var(--font-size-md);
  color: var(--color-text-primary);
  font-weight: 600;
}

/* ========================================
   PROTECTION STATUS
   ======================================== */
.protection-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(180px, 1fr));
  gap: var(--space-md);
}

.protection-badge {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  padding: var(--space-sm) var(--space-md);
  border-radius: var(--radius-md);
  font-size: var(--font-size-xs);
  font-weight: 600;
  text-align: center;
  transition: all var(--transition-base);
}

.protection-badge--enabled {
  background: var(--color-danger);
  color: white;
  animation: alertPulse 1.5s ease-in-out infinite;
}

.protection-badge--disabled {
  background: var(--color-bg-primary);
  color: var(--color-text-tertiary);
}

@keyframes alertPulse {
  0%, 100% {
    opacity: 1;
    transform: scale(1);
  }
  50% {
    opacity: 0.8;
    transform: scale(1.02);
  }
}

/* ========================================
   HISTORY / GRAPHS VIEW
   ======================================== */
.history-view {
  width: 100%;
}

.graph-container {
  display: flex;
  flex-direction: column;
  gap: var(--space-xl);
}

.graph-card {
  background: var(--color-bg-secondary);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-lg);
  box-shadow: var(--shadow-sm);
  overflow: hidden;
}

.graph-card__header {
  padding: var(--space-lg);
  border-bottom: 1px solid var(--color-border-light);
}

.graph-card__title {
  font-size: var(--font-size-lg);
  font-weight: 600;
  color: var(--color-text-primary);
  margin: 0;
}

.graph-card__body {
  padding: var(--space-lg);
  min-height: 300px;
  display: flex;
  justify-content: center;
  align-items: center;
}

/* D3 Graph Styling */
.graph-card__body svg {
  max-width: 100%;
  height: auto;
  font-family: var(--font-family);
}

/* Axis styling */
.graph-card__body svg text {
  fill: var(--color-text-secondary);
  font-size: var(--font-size-xs);
}

.graph-card__body svg .domain {
  stroke: var(--color-border);
}

.graph-card__body svg .tick line {
  stroke: var(--color-border);
}

/* Grid lines */
.graph-card__body svg .tick line[stroke-opacity="0.1"] {
  stroke: var(--color-border-light);
  stroke-opacity: 0.3 !important;
}

/* Line colors - override D3 defaults */
.graph-card__body svg path[stroke="steelblue"] {
  stroke: var(--color-accent-light) !important;
  stroke-width: 2px;
  filter: drop-shadow(0 0 4px rgba(59, 130, 246, 0.3));
}

.graph-card__body svg path[stroke="green"] {
  stroke: var(--color-success) !important;
  stroke-width: 2px;
}

.graph-card__body svg path[stroke="orange"] {
  stroke: var(--color-warning) !important;
  stroke-width: 2px;
}

.graph-card__body svg path[stroke="red"] {
  stroke: var(--color-danger) !important;
  stroke-width: 2px;
}

/* Multiple line colors for cell voltages */
.graph-card__body svg path[stroke]:not([stroke="none"]) {
  stroke-width: 2px;
  transition: stroke-width var(--transition-fast);
}

.graph-card__body svg path[stroke]:not([stroke="none"]):hover {
  stroke-width: 3px;
}

/* Axis labels */
.graph-card__body svg text[text-anchor="start"] {
  fill: var(--color-text-primary);
  font-weight: 600;
  font-size: var(--font-size-sm);
}

/* Empty state for graphs */
.graph-card__body:empty::after {
  content: "No data available";
  color: var(--color-text-tertiary);
  font-size: var(--font-size-sm);
  text-align: center;
}

/* ========================================
   LOADING STATES
   ======================================== */
.loading {
  position: relative;
  pointer-events: none;
  opacity: 0.6;
}

.loading::after {
  content: "";
  position: absolute;
  top: 50%;
  left: 50%;
  width: 24px;
  height: 24px;
  margin: -12px 0 0 -12px;
  border: 3px solid var(--color-border);
  border-top-color: var(--color-accent-primary);
  border-radius: 50%;
  animation: spin 0.8s linear infinite;
  z-index: 10;
}

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

/* Loading Overlay */
.loading-overlay {
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  bottom: 0;
  background: rgba(26, 29, 41, 0.85);
  backdrop-filter: blur(4px);
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  gap: var(--space-md);
  z-index: 100;
  animation: fadeIn 0.3s ease-out;
}

@keyframes fadeIn {
  from {
    opacity: 0;
  }
  to {
    opacity: 1;
  }
}

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

.loading-spinner {
  width: 40px;
  height: 40px;
  border: 4px solid var(--color-border);
  border-top-color: var(--color-accent-primary);
  border-radius: 50%;
  animation: spin 0.8s linear infinite;
}

.loading-text {
  color: var(--color-text-secondary);
  font-size: var(--font-size-sm);
  font-weight: 500;
  text-align: center;
}

/* Apply relative positioning to containers that will have loading overlays */
.card__body {
  position: relative;
}

/* ========================================
   MICRO-INTERACTIONS & POLISH
   ======================================== */

/* Smooth scrolling */
html {
  scroll-behavior: smooth;
  /* Better scrolling on mobile */
  -webkit-overflow-scrolling: touch;
}

/* Focus visible for keyboard navigation */
:focus-visible {
  outline: 2px solid var(--color-accent-primary);
  outline-offset: 2px;
}

/* Remove focus outline for mouse users */
:focus:not(:focus-visible) {
  outline: none;
}

/* Selection color */
::selection {
  background: var(--color-accent-primary);
  color: white;
}

/* Card hover lift effect enhancement */
.card {
  transition: all var(--transition-base);
}

@media (hover: hover) {
  .card:hover {
    transform: translateY(-2px);
  }
  
  .btn:hover {
    transform: translateY(-1px);
  }
}

@media (hover: none) {
  .card:hover {
    transform: none;
  }
  
  .btn:hover {
    transform: none;
    box-shadow: none;
  }
}

/* Animated entry for cards */
@keyframes fadeInUp {
  from {
    opacity: 0;
    transform: translateY(20px);
  }
  to {
    opacity: 1;
    transform: translateY(0);
  }
}

.card {
  animation: fadeInUp 0.4s ease-out backwards;
}

.card:nth-child(1) { animation-delay: 0.05s; }
.card:nth-child(2) { animation-delay: 0.1s; }
.card:nth-child(3) { animation-delay: 0.15s; }
.card:nth-child(4) { animation-delay: 0.2s; }
.card:nth-child(5) { animation-delay: 0.25s; }

/* Smooth value changes */
.metric__value,
.cell-item__value,
.info-list__value {
  transition: color var(--transition-fast);
}

/* Number change flash effect */
@keyframes flash {
  0%, 100% {
    opacity: 1;
  }
  50% {
    opacity: 0.7;
  }
}

.value-changed {
  animation: flash 0.3s ease-in-out;
}

/* Button press effect */
.btn:active {
  transform: translateY(0) scale(0.98);
}

/* Status badge connect animation */
@keyframes slideIn {
  from {
    transform: translateX(-10px);
    opacity: 0;
  }
  to {
    transform: translateX(0);
    opacity: 1;
  }
}

.status-badge {
  animation: slideIn 0.3s ease-out;
}

/* Scrollbar styling */
::-webkit-scrollbar {
  width: 10px;
  height: 10px;
}

::-webkit-scrollbar-track {
  background: var(--color-bg-primary);
}

::-webkit-scrollbar-thumb {
  background: var(--color-bg-tertiary);
  border-radius: var(--radius-sm);
}

::-webkit-scrollbar-thumb:hover {
  background: var(--color-bg-hover);
}

/* Firefox scrollbar */
* {
  scrollbar-width: thin;
  scrollbar-color: var(--color-bg-tertiary) var(--color-bg-primary);
}

/* ========================================
   DASHBOARD CHART COMPONENTS
   ======================================== */

/* Battery Status Grid Layout */
.battery-status-grid {
  display: grid;
  grid-template-columns: 200px 1fr;
  gap: var(--space-xl);
  align-items: center;
}

.battery-gauges-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(150px, 1fr));
  gap: var(--space-lg);
  align-items: center;
}

.battery-status-item {
  display: flex;
  justify-content: center;
  align-items: center;
}

/* SOC Donut Chart Container */
.soc-donut-container {
  display: flex;
  justify-content: center;
  align-items: center;
  min-height: 200px;
}

.soc-donut-chart {
  display: block;
  margin: 0 auto;
}

/* Gauge Container */
.gauge-container {
  display: flex;
  justify-content: center;
  align-items: center;
  min-height: 140px;
}

.semi-gauge-chart {
  display: block;
  margin: 0 auto;
}

/* Cell Voltage Bar Chart Container */
.cell-voltage-chart-container {
  width: 100%;
  min-height: 300px;
  overflow-x: auto;
}

.cell-voltage-chart {
  display: block;
  max-width: 100%;
  height: auto;
}

/* Temperature Gauge Container */
.temperature-gauge-container {
  width: 100%;
  min-height: 200px;
}

.temperature-gauges {
  width: 100%;
}

.temp-gauge-row {
  width: 100%;
}

/* Capacity Progress Bar */
.capacity-progress-wrapper {
  width: 100%;
}

/* Chart Animations */
@keyframes chartFadeIn {
  from {
    opacity: 0;
    transform: scale(0.95);
  }
  to {
    opacity: 1;
    transform: scale(1);
  }
}

.soc-donut-chart,
.semi-gauge-chart,
.cell-voltage-chart {
  animation: chartFadeIn 0.5s ease-out;
}

/* Value Update Flash Effect */
@keyframes valueFlash {
  0% {
    filter: brightness(1);
  }
  50% {
    filter: brightness(1.5);
  }
  100% {
    filter: brightness(1);
  }
}

.value-flash {
  animation: valueFlash 0.3s ease-in-out;
}

/* Gauge Needle Animation */
.semi-gauge-chart line {
  transition: all 0.5s cubic-bezier(0.4, 0, 0.2, 1);
}

/* Chart Text Styling */
.soc-donut-chart text,
.semi-gauge-chart text {
  user-select: none;
  pointer-events: none;
}

/* Responsive Chart Adjustments */
@media (max-width: 1024px) {
  .battery-status-grid {
    grid-template-columns: 1fr;
    gap: var(--space-lg);
  }
  
  .battery-gauges-grid {
    grid-template-columns: repeat(2, 1fr);
  }
}

@media (max-width: 768px) {
  .battery-status-grid {
    grid-template-columns: 1fr;
  }
  
  .battery-gauges-grid {
    grid-template-columns: 1fr;
  }
  
  .soc-donut-container {
    min-height: 180px;
  }
  
  .gauge-container {
    min-height: 120px;
  }
}

@media (max-width: 480px) {
  .battery-status-grid {
    gap: var(--space-md);
  }
  
  .battery-gauges-grid {
    gap: var(--space-md);
  }
  
  .cell-voltage-chart-container {
    min-height: 250px;
  }
  
  .temperature-gauge-container {
    min-height: 180px;
  }
}

/* ========================================
   RESPONSIVE DESIGN
   ======================================== */

/* Tablet and below */
@media (max-width: 1024px) {
  :root {
    --space-xl: 1.5rem;
    --space-2xl: 2rem;
  }
  
  .metrics__grid {
    grid-template-columns: 1fr;
  }
  
  .cells-grid {
    grid-template-columns: repeat(auto-fill, minmax(140px, 1fr));
    gap: var(--space-md);
  }
  
  .secondary-info__grid {
    grid-template-columns: 1fr;
  }
  
  .card--span-2 {
    grid-column: span 1;
  }
}

/* Tablet and below */
@media (max-width: 768px) {
  :root {
    --font-size-3xl: 1.75rem;
    --font-size-2xl: 1.375rem;
    --font-size-xl: 1.125rem;
    --space-lg: 1rem;
    --space-xl: 1.25rem;
  }
  
  /* Header improvements for tablet */
  .app-header {
    padding: var(--space-md) var(--space-lg);
    position: relative;
  }
  
  .app-header__container {
    display: grid;
    grid-template-columns: 1fr;
    gap: var(--space-md);
  }
  
  .app-header__brand {
    order: 1;
  }
  
  .app-header__actions {
    order: 3;
    justify-content: stretch;
  }
  
  .app-header__actions .btn {
    flex: 1;
    min-width: 0;
  }
  
  .app-header__status {
    order: 2;
    justify-content: space-between;
    width: 100%;
  }
  
  .app-header__title {
    font-size: var(--font-size-xl);
  }
  
  /* Main content */
  .app-main {
    padding: var(--space-md);
  }
  
  /* View navigation */
  .view-nav {
    padding: 0 var(--space-lg);
    position: sticky;
    top: 0;
    z-index: 99;
    background: var(--color-bg-secondary);
  }
  
  .view-nav__btn {
    flex: 1;
    justify-content: center;
    min-height: 48px;
  }
  
  /* Cards */
  .card__header {
    padding: var(--space-md);
    flex-wrap: wrap;
  }
  
  .card__body {
    padding: var(--space-md);
  }
  
  .card__header-info {
    width: 100%;
    justify-content: flex-start;
  }
  
  /* Metrics */
  .metric-row {
    grid-template-columns: 1fr;
    gap: var(--space-md);
  }
  
  /* Cells grid - 2 columns on tablet */
  .cells-grid {
    grid-template-columns: repeat(auto-fill, minmax(130px, 1fr));
    gap: var(--space-md);
  }
  
  /* Protection grid - 2 columns */
  .protection-grid {
    grid-template-columns: repeat(2, 1fr);
    gap: var(--space-sm);
  }
  
  .protection-badge {
    font-size: var(--font-size-xs);
    padding: var(--space-xs) var(--space-sm);
  }
  
  /* Graph cards */
  .graph-card__body {
    padding: var(--space-sm);
    min-height: 250px;
  }
}

/* Mobile landscape and small tablets */
@media (max-width: 640px) {
  :root {
    --space-md: 0.75rem;
    --space-lg: 1rem;
  }
  
  /* Navigation */
  .view-nav__text {
    display: none;
  }
  
  .view-nav__icon {
    font-size: var(--font-size-xl);
  }
  
  .view-nav__btn {
    min-height: 52px;
    padding: var(--space-md);
  }
  
  /* Single column cells */
  .cells-grid {
    grid-template-columns: repeat(2, 1fr);
  }
}

/* Mobile portrait */
@media (max-width: 480px) {
  :root {
    --font-size-3xl: 1.5rem;
    --font-size-2xl: 1.25rem;
    --font-size-xl: 1.125rem;
    --font-size-lg: 1rem;
    --space-xs: 0.25rem;
    --space-sm: 0.5rem;
    --space-md: 0.75rem;
    --space-lg: 1rem;
    --space-xl: 1.25rem;
  }
  
  /* Header for mobile */
  .app-header {
    padding: var(--space-sm) var(--space-md);
  }
  
  .app-header__title {
    font-size: var(--font-size-lg);
  }
  
  .app-header__subtitle {
    font-size: var(--font-size-xs);
  }
  
  /* Buttons */
  .btn {
    font-size: var(--font-size-sm);
    padding: var(--space-sm) var(--space-md);
    min-height: 44px;
  }
  
  .btn__text {
    display: none;
  }
  
  .btn__icon {
    font-size: var(--font-size-xl);
    margin: 0;
  }
  
  .app-header__actions {
    gap: var(--space-sm);
  }
  
  .app-header__actions .btn {
    min-width: 44px;
    padding: var(--space-sm);
  }
  
  /* Status badge compact */
  .status-badge {
    padding: var(--space-xs) var(--space-sm);
    font-size: var(--font-size-xs);
  }
  
  .app-header__timestamp {
    font-size: var(--font-size-xs);
  }
  
  /* Main content */
  .app-main {
    padding: var(--space-sm);
  }
  
  .dashboard {
    gap: var(--space-md);
  }
  
  /* View navigation - full width icons */
  .view-nav {
    padding: 0 var(--space-md);
  }
  
  .view-nav__container {
    gap: 0;
  }
  
  .view-nav__btn {
    border-radius: 0;
    min-height: 56px;
  }
  
  /* Cards */
  .card__header {
    padding: var(--space-md);
  }
  
  .card__body {
    padding: var(--space-md);
  }
  
  .card__title {
    font-size: var(--font-size-md);
  }
  
  /* Metrics - larger touch targets */
  .metric--large {
    padding-bottom: var(--space-md);
    margin-bottom: var(--space-md);
  }
  
  .metric__value {
    font-size: var(--font-size-xl);
  }
  
  .metric--large .metric__value {
    font-size: var(--font-size-3xl);
  }
  
  .metric__label {
    font-size: var(--font-size-xs);
  }
  
  .metric-row {
    gap: var(--space-md);
  }
  
  /* Cell voltages - single column on small mobile */
  .cells-grid {
    grid-template-columns: 1fr;
    gap: var(--space-sm);
  }
  
  .cell-item {
    padding: var(--space-md);
  }
  
  .cell-item__value {
    font-size: var(--font-size-lg);
  }
  
  /* Info lists */
  .info-list {
    gap: var(--space-sm);
  }
  
  .info-list__item {
    flex-wrap: wrap;
    gap: var(--space-xs);
  }
  
  .info-list__label,
  .info-list__value {
    font-size: var(--font-size-sm);
  }
  
  /* Status indicators */
  .status-indicators {
    gap: var(--space-sm);
  }
  
  .status-indicator__badge {
    padding: var(--space-sm) var(--space-md);
    font-size: var(--font-size-sm);
    justify-content: center;
    width: 100%;
  }
  
  /* Protection grid - single column for easy reading */
  .protection-grid {
    grid-template-columns: 1fr;
    gap: var(--space-xs);
  }
  
  .protection-badge {
    padding: var(--space-sm) var(--space-md);
    font-size: var(--font-size-sm);
    min-height: 44px;
    display: flex;
    align-items: center;
    justify-content: center;
  }
  
  /* Graph improvements */
  .graph-card__header {
    padding: var(--space-md);
  }
  
  .graph-card__title {
    font-size: var(--font-size-md);
  }
  
  .graph-card__body {
    padding: var(--space-sm);
    min-height: 200px;
  }
  
  /* Reduce animations on mobile for performance */
  .card {
    animation: none;
  }
  
  .card:hover {
    transform: none;
  }
}

/* Very small mobile devices */
@media (max-width: 360px) {
  :root {
    --font-size-3xl: 1.375rem;
    --font-size-2xl: 1.125rem;
  }
  
  .app-header__container {
    gap: var(--space-sm);
  }
  
  .metric--large .metric__value {
    font-size: var(--font-size-2xl);
  }
  
  .cell-item__value {
    font-size: var(--font-size-md);
  }
}

/* Landscape mode optimization */
@media (max-height: 500px) and (orientation: landscape) {
  .app-header {
    position: relative;
  }
  
  .view-nav {
    position: relative;
  }
  
  .app-header__container {
    display: flex;
    flex-direction: row;
    flex-wrap: wrap;
    align-items: center;
  }
  
  .app-header__brand {
    flex: 1;
    min-width: 150px;
  }
  
  .app-header__actions {
    flex: 0 0 auto;
  }
  
  .app-header__status {
    flex: 0 0 auto;
  }
  
  .graph-card__body {
    min-height: 250px;
  }
}