/* ==========================================================================
   TAF Fuel Dashboard — Design Tokens & Styles
   Agricultural color palette: forest green primary, warm neutrals
   ========================================================================== */

/* --- Design Tokens --- */
:root {
  /* Type Scale (fluid) */
  --text-xs:   clamp(0.75rem,  0.7rem  + 0.25vw, 0.875rem);
  --text-sm:   clamp(0.875rem, 0.8rem  + 0.35vw, 1rem);
  --text-base: clamp(1rem,     0.95rem + 0.25vw, 1.125rem);
  --text-lg:   clamp(1.125rem, 1rem    + 0.75vw, 1.5rem);
  --text-xl:   clamp(1.5rem,   1.2rem  + 1.25vw, 2.25rem);
  --text-2xl:  clamp(2rem,     1.2rem  + 2.5vw,  3.5rem);

  /* 4px Spacing */
  --space-1:  0.25rem;
  --space-2:  0.5rem;
  --space-3:  0.75rem;
  --space-4:  1rem;
  --space-5:  1.25rem;
  --space-6:  1.5rem;
  --space-8:  2rem;
  --space-10: 2.5rem;
  --space-12: 3rem;
  --space-16: 4rem;

  /* Radius */
  --radius-sm: 0.375rem;
  --radius-md: 0.5rem;
  --radius-lg: 0.75rem;
  --radius-xl: 1rem;

  /* Transitions */
  --transition-interactive: 180ms cubic-bezier(0.16, 1, 0.3, 1);

  /* Font */
  --font-body: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', sans-serif;

  /* Content widths */
  --content-wide: 1400px;
}

/* --- Light Mode --- */
:root, [data-theme="light"] {
  --color-bg:             #f5f3ee;
  --color-surface:        #faf9f6;
  --color-surface-2:      #ffffff;
  --color-surface-offset: #edeae3;
  --color-divider:        #d9d5cc;
  --color-border:         #ccc8be;

  --color-text:           #1a1a18;
  --color-text-muted:     #6b6960;
  --color-text-faint:     #a09e96;
  --color-text-inverse:   #faf9f6;

  --color-primary:        #2d5016;
  --color-primary-hover:  #1f3a0f;
  --color-primary-active: #152a09;
  --color-primary-surface: #e8f0e2;

  --color-success:        #2d7a1e;
  --color-success-surface: #e4f2df;
  --color-warning:        #b8860b;
  --color-warning-surface: #fef3d6;
  --color-danger:         #b91c1c;
  --color-danger-surface:  #fde8e8;

  --shadow-sm: 0 1px 2px rgba(0,0,0,0.05);
  --shadow-md: 0 4px 12px rgba(0,0,0,0.08);
  --shadow-lg: 0 8px 24px rgba(0,0,0,0.1);
}

/* --- Dark Mode (default) --- */
[data-theme="dark"] {
  --color-bg:             #141613;
  --color-surface:        #1a1d18;
  --color-surface-2:      #21241f;
  --color-surface-offset: #1e211c;
  --color-divider:        #2a2d27;
  --color-border:         #353830;

  --color-text:           #d4d3ce;
  --color-text-muted:     #8a8880;
  --color-text-faint:     #5c5a53;
  --color-text-inverse:   #1a1d18;

  --color-primary:        #5a9a3a;
  --color-primary-hover:  #4a8530;
  --color-primary-active: #3a7025;
  --color-primary-surface: #1e2a17;

  --color-success:        #5aad40;
  --color-success-surface: #1a2a14;
  --color-warning:        #d4a020;
  --color-warning-surface: #2a2410;
  --color-danger:         #e84040;
  --color-danger-surface:  #2a1414;

  --shadow-sm: 0 1px 2px rgba(0,0,0,0.2);
  --shadow-md: 0 4px 12px rgba(0,0,0,0.3);
  --shadow-lg: 0 8px 24px rgba(0,0,0,0.35);
}

@media (prefers-color-scheme: dark) {
  :root:not([data-theme]) {
    --color-bg:             #141613;
    --color-surface:        #1a1d18;
    --color-surface-2:      #21241f;
    --color-surface-offset: #1e211c;
    --color-divider:        #2a2d27;
    --color-border:         #353830;
    --color-text:           #d4d3ce;
    --color-text-muted:     #8a8880;
    --color-text-faint:     #5c5a53;
    --color-text-inverse:   #1a1d18;
    --color-primary:        #5a9a3a;
    --color-primary-hover:  #4a8530;
    --color-primary-active: #3a7025;
    --color-primary-surface: #1e2a17;
    --color-success:        #5aad40;
    --color-success-surface: #1a2a14;
    --color-warning:        #d4a020;
    --color-warning-surface: #2a2410;
    --color-danger:         #e84040;
    --color-danger-surface:  #2a1414;
    --shadow-sm: 0 1px 2px rgba(0,0,0,0.2);
    --shadow-md: 0 4px 12px rgba(0,0,0,0.3);
    --shadow-lg: 0 8px 24px rgba(0,0,0,0.35);
  }
}

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

html {
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
  text-rendering: optimizeLegibility;
  text-size-adjust: none;
  -webkit-text-size-adjust: none;
}

body {
  font-family: var(--font-body);
  font-size: var(--text-base);
  color: var(--color-text);
  background-color: var(--color-bg);
  line-height: 1.5;
  min-height: 100dvh;
  display: flex;
  flex-direction: column;
}

img, picture, video, canvas, svg { display: block; max-width: 100%; }
input, button, textarea, select { font: inherit; color: inherit; }
button { cursor: pointer; background: none; border: none; }

h1, h2, h3 { text-wrap: balance; line-height: 1.2; }
p { text-wrap: pretty; }

::selection {
  background: rgba(45, 80, 22, 0.25);
  color: var(--color-text);
}

:focus-visible {
  outline: 2px solid var(--color-primary);
  outline-offset: 3px;
  border-radius: var(--radius-sm);
}

a, button, [role="button"] {
  transition: color var(--transition-interactive),
              background var(--transition-interactive),
              border-color var(--transition-interactive),
              box-shadow var(--transition-interactive);
}

@media (prefers-reduced-motion: reduce) {
  *, *::before, *::after {
    animation-duration: 0.01ms !important;
    transition-duration: 0.01ms !important;
  }
}

/* --- Header --- */
.header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: var(--space-4) var(--space-6);
  background: var(--color-surface);
  border-bottom: 1px solid var(--color-divider);
  position: sticky;
  top: 0;
  z-index: 100;
}

.header-left {
  display: flex;
  align-items: center;
  gap: var(--space-3);
}

.logo svg {
  display: block;
}

.header-titles {
  display: flex;
  flex-direction: column;
}

.header-title {
  font-size: var(--text-lg);
  font-weight: 700;
  color: var(--color-text);
  letter-spacing: -0.02em;
}

.header-subtitle {
  font-size: var(--text-xs);
  color: var(--color-text-muted);
  font-weight: 500;
  text-transform: uppercase;
  letter-spacing: 0.06em;
}

.header-right {
  display: flex;
  align-items: center;
  gap: var(--space-4);
}

.last-updated {
  font-size: var(--text-xs);
  color: var(--color-text-faint);
  font-variant-numeric: tabular-nums;
}

.theme-toggle {
  display: flex;
  align-items: center;
  justify-content: center;
  width: 36px;
  height: 36px;
  border-radius: var(--radius-md);
  color: var(--color-text-muted);
  background: var(--color-surface-offset);
}

.theme-toggle:hover {
  color: var(--color-text);
  background: var(--color-divider);
}

/* --- Main --- */
.main {
  flex: 1;
  padding: var(--space-6);
  max-width: var(--content-wide);
  width: 100%;
  margin: 0 auto;
  display: flex;
  flex-direction: column;
  gap: var(--space-6);
}

/* --- Alerts --- */
.alerts-section {
  display: flex;
  flex-direction: column;
  gap: var(--space-2);
}

.alert {
  display: flex;
  align-items: center;
  gap: var(--space-3);
  padding: var(--space-3) var(--space-4);
  border-radius: var(--radius-md);
  font-size: var(--text-sm);
  font-weight: 500;
}

.alert--danger {
  background: var(--color-danger-surface);
  color: var(--color-danger);
  border: 1px solid var(--color-danger);
}

.alert--warning {
  background: var(--color-warning-surface);
  color: var(--color-warning);
  border: 1px solid var(--color-warning);
}

.alert-icon {
  flex-shrink: 0;
  width: 20px;
  height: 20px;
}

/* --- Gauge Cards --- */
.gauges-section {
  width: 100%;
}

.gauges-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: var(--space-4);
}

.gauge-card {
  background: var(--color-surface);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-lg);
  padding: var(--space-5) var(--space-4) var(--space-4);
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: var(--space-2);
  box-shadow: var(--shadow-sm);
}

.gauge-card--large {
  grid-column: span 1;
}

.gauge-card--small {
  grid-column: span 1;
}

/* On desktop: 3 large tanks on top row, 2 small tanks centered below */
@media (min-width: 900px) {
  .gauges-grid {
    grid-template-columns: repeat(6, 1fr);
  }
  .gauge-card--large {
    grid-column: span 2;
  }
  .gauge-card--small {
    grid-column: span 2;
  }
  .gauge-card--small:nth-of-type(4) {
    grid-column: 2 / span 2;
  }
  .gauge-card--small:nth-of-type(5) {
    grid-column: 4 / span 2;
  }
}

.gauge-visual {
  display: flex;
  align-items: center;
  justify-content: center;
}

.gauge-visual canvas {
  display: block;
}

.gauge-info {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: var(--space-1);
  text-align: center;
}

.gauge-label {
  font-size: var(--text-sm);
  font-weight: 600;
  color: var(--color-text);
  letter-spacing: -0.01em;
}

.gauge-value {
  font-size: var(--text-xl);
  font-weight: 700;
  color: var(--color-text);
  font-variant-numeric: tabular-nums lining-nums;
  letter-spacing: -0.02em;
}

.gauge-capacity {
  font-size: var(--text-xs);
  color: var(--color-text-faint);
  font-variant-numeric: tabular-nums;
}

.gauge-days {
  font-size: var(--text-xs);
  color: var(--color-text-muted);
  font-weight: 500;
  font-variant-numeric: tabular-nums;
}

.projection-note {
  text-align: center;
  font-size: var(--text-xs);
  color: var(--color-text-faint);
  margin-top: var(--space-4);
  font-style: italic;
}

/* --- Chart Sections --- */
.chart-section {
  background: var(--color-surface);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-lg);
  padding: var(--space-5) var(--space-5) var(--space-4);
  box-shadow: var(--shadow-sm);
}

.chart-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  margin-bottom: var(--space-4);
  flex-wrap: wrap;
  gap: var(--space-3);
}

.section-title {
  font-size: var(--text-lg);
  font-weight: 600;
  color: var(--color-text);
  letter-spacing: -0.01em;
}

.toggle-group {
  display: flex;
  gap: var(--space-1);
  background: var(--color-surface-offset);
  border-radius: var(--radius-md);
  padding: var(--space-1);
}

.toggle-btn {
  font-size: var(--text-xs);
  font-weight: 500;
  padding: var(--space-1) var(--space-3);
  border-radius: var(--radius-sm);
  color: var(--color-text-muted);
  white-space: nowrap;
}

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

.toggle-btn.active {
  background: var(--color-primary);
  color: var(--color-text-inverse);
}

[data-theme="light"] .toggle-btn.active {
  color: #fff;
}

.chart-container {
  position: relative;
  width: 100%;
  height: 360px;
}

.chart-container canvas {
  width: 100% !important;
  height: 100% !important;
}

/* --- Footer --- */
.footer {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: var(--space-4) var(--space-6);
  border-top: 1px solid var(--color-divider);
  font-size: var(--text-xs);
  color: var(--color-text-faint);
}

.footer a {
  color: var(--color-text-muted);
  text-decoration: none;
}

.footer a:hover {
  color: var(--color-primary);
  text-decoration: underline;
}

/* --- Responsive --- */
@media (max-width: 899px) {
  .gauges-grid {
    grid-template-columns: 1fr 1fr;
    gap: var(--space-3);
  }

  .gauge-card--large:first-child {
    grid-column: 1 / -1;
  }

  .gauge-value {
    font-size: var(--text-lg);
  }

  .chart-container {
    height: 280px;
  }
}

@media (max-width: 600px) {
  .header {
    padding: var(--space-3) var(--space-4);
  }

  .header-title {
    font-size: var(--text-base);
  }

  .header-subtitle {
    display: none;
  }

  .main {
    padding: var(--space-4) var(--space-3);
    gap: var(--space-4);
  }

  .gauges-grid {
    grid-template-columns: 1fr;
    gap: var(--space-3);
  }

  .gauge-card--large,
  .gauge-card--small {
    grid-column: span 1;
    flex-direction: row;
    padding: var(--space-3) var(--space-4);
    gap: var(--space-4);
  }

  .gauge-info {
    align-items: flex-start;
    text-align: left;
  }

  .gauge-visual canvas {
    width: 100px !important;
    height: 65px !important;
  }

  .chart-section {
    padding: var(--space-3);
  }

  .chart-container {
    height: 240px;
  }

  .toggle-group {
    width: 100%;
    justify-content: center;
  }

  .footer {
    flex-direction: column;
    gap: var(--space-2);
    text-align: center;
    padding: var(--space-3) var(--space-4);
  }
}

/* --- Fleet Section --- */
.fleet-section {
  background: var(--color-surface);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-lg);
  padding: var(--space-5) var(--space-5) var(--space-4);
  box-shadow: var(--shadow-sm);
  display: flex;
  flex-direction: column;
  gap: var(--space-4);
}

.fleet-kpis {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: var(--space-3);
}

.fleet-kpi {
  background: var(--color-surface-2);
  border: 1px solid var(--color-divider);
  border-radius: var(--radius-md);
  padding: var(--space-3) var(--space-4);
  display: flex;
  flex-direction: column;
  gap: var(--space-1);
}

.fleet-kpi-label {
  font-size: var(--text-xs);
  color: var(--color-text-muted);
  font-weight: 500;
  text-transform: uppercase;
  letter-spacing: 0.04em;
}

.fleet-kpi-value {
  font-size: var(--text-lg);
  font-weight: 700;
  color: var(--color-text);
  font-variant-numeric: tabular-nums lining-nums;
  letter-spacing: -0.02em;
}

.fleet-kpi-unit {
  font-size: var(--text-xs);
  color: var(--color-text-faint);
}

.chart-container--fleet {
  position: relative;
  width: 100%;
  height: 300px;
}

.chart-container--fleet canvas {
  width: 100% !important;
  height: 100% !important;
}

/* Fleet Table */
.fleet-table-wrap {
  overflow-x: auto;
  -webkit-overflow-scrolling: touch;
}

.fleet-table {
  width: 100%;
  border-collapse: collapse;
  font-size: var(--text-sm);
  font-variant-numeric: tabular-nums lining-nums;
}

.fleet-table thead {
  position: sticky;
  top: 0;
  z-index: 1;
}

.fleet-table th {
  text-align: left;
  font-weight: 600;
  font-size: var(--text-xs);
  color: var(--color-text-muted);
  text-transform: uppercase;
  letter-spacing: 0.04em;
  padding: var(--space-2) var(--space-3);
  border-bottom: 2px solid var(--color-divider);
  background: var(--color-surface);
  white-space: nowrap;
}

.fleet-table th.num,
.fleet-table td.num {
  text-align: right;
}

.fleet-table td {
  padding: var(--space-2) var(--space-3);
  border-bottom: 1px solid var(--color-divider);
  color: var(--color-text);
  white-space: nowrap;
}

.fleet-table tbody tr:hover {
  background: var(--color-surface-offset);
}

.fleet-table tfoot td {
  font-weight: 700;
  border-top: 2px solid var(--color-divider);
  border-bottom: none;
  color: var(--color-text);
}

.fleet-table .vehicle-name {
  font-weight: 500;
  color: var(--color-text);
}

.fleet-table .idle-high {
  color: var(--color-warning);
  font-weight: 600;
}

.fleet-source {
  font-size: var(--text-xs);
  color: var(--color-text-faint);
  font-style: italic;
}

@media (max-width: 899px) {
  .fleet-kpis {
    grid-template-columns: repeat(2, 1fr);
  }
}

@media (max-width: 600px) {
  .fleet-section {
    padding: var(--space-3);
  }

  .fleet-kpis {
    grid-template-columns: 1fr 1fr;
    gap: var(--space-2);
  }

  .fleet-kpi {
    padding: var(--space-2) var(--space-3);
  }

  .chart-container--fleet {
    height: 240px;
  }

  .fleet-table {
    font-size: var(--text-xs);
  }

  .fleet-table th,
  .fleet-table td {
    padding: var(--space-1) var(--space-2);
  }
}

/* --- Utility --- */
.sr-only {
  position: absolute; width: 1px; height: 1px; padding: 0; margin: -1px;
  overflow: hidden; clip: rect(0, 0, 0, 0); white-space: nowrap; border-width: 0;
}