/* ============================================
   Spacer - Truck Loading Optimizer
   Modern Dark UI with Glass Morphism
   ============================================ */

@import url('https://fonts.googleapis.com/css2?family=Inter:wght@300;400;500;600;700;800&display=swap');

:root {
  --bg-primary: #06060f;
  --bg-secondary: #0d0d1a;
  --bg-card: rgba(15, 15, 30, 0.7);
  --bg-glass: rgba(20, 20, 45, 0.5);
  --border-color: rgba(74, 158, 255, 0.12);
  --border-glow: rgba(74, 158, 255, 0.25);
  --accent: #4a9eff;
  --accent-glow: rgba(74, 158, 255, 0.4);
  --accent-secondary: #7c5cff;
  --success: #34d399;
  --warning: #fbbf24;
  --danger: #f87171;
  --text-primary: #e8eaf0;
  --text-secondary: #8890a4;
  --text-dim: #4a5068;
  --radius: 12px;
  --radius-sm: 8px;
  --transition: 0.2s cubic-bezier(0.4, 0, 0.2, 1);
}

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

html, body {
  height: 100%;
  font-family: 'Inter', system-ui, -apple-system, sans-serif;
  background: var(--bg-primary);
  color: var(--text-primary);
  overflow: hidden;
}

/* Layout */
.app {
  display: grid;
  grid-template-columns: 380px 1fr;
  grid-template-rows: auto 1fr;
  height: 100vh;
  gap: 0;
}

/* Header */
.header {
  grid-column: 1 / -1;
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 12px 24px;
  background: var(--bg-secondary);
  border-bottom: 1px solid var(--border-color);
  z-index: 10;
}

.header-brand {
  display: flex;
  align-items: center;
  gap: 12px;
}

.header-brand .logo {
  width: 36px;
  height: 36px;
  background: linear-gradient(135deg, var(--accent), var(--accent-secondary));
  border-radius: var(--radius-sm);
  display: flex;
  align-items: center;
  justify-content: center;
  font-weight: 800;
  font-size: 16px;
  color: white;
}

.header-brand h1 {
  font-size: 18px;
  font-weight: 700;
  letter-spacing: -0.5px;
}

.header-brand span {
  color: var(--text-secondary);
  font-size: 12px;
  font-weight: 400;
}

.header-stats {
  display: flex;
  gap: 24px;
  align-items: center;
}

.stat-pill {
  display: flex;
  align-items: center;
  gap: 8px;
  padding: 6px 14px;
  background: var(--bg-glass);
  border: 1px solid var(--border-color);
  border-radius: 20px;
  font-size: 12px;
  font-weight: 500;
  color: var(--text-secondary);
  transition: var(--transition);
}

.stat-pill .value {
  color: var(--accent);
  font-weight: 700;
  font-variant-numeric: tabular-nums;
}

.stat-pill.warning .value { color: var(--warning); }
.stat-pill.danger .value { color: var(--danger); }
.stat-pill.success .value { color: var(--success); }

/* Sidebar */
.sidebar {
  background: var(--bg-secondary);
  border-right: 1px solid var(--border-color);
  overflow-y: auto;
  display: flex;
  flex-direction: column;
}

.sidebar::-webkit-scrollbar { width: 4px; }
.sidebar::-webkit-scrollbar-track { background: transparent; }
.sidebar::-webkit-scrollbar-thumb { background: var(--border-color); border-radius: 4px; }

/* Sections */
.section {
  padding: 20px;
  border-bottom: 1px solid var(--border-color);
}

.section-title {
  font-size: 13px;
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 1.2px;
  color: var(--text-dim);
  margin-bottom: 14px;
}

/* Truck Config */
.truck-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 10px;
}

.truck-grid .full-width {
  grid-column: 1 / -1;
}

/* Input Groups */
.input-group {
  position: relative;
}

.input-group label {
  display: block;
  font-size: 12px;
  font-weight: 500;
  color: var(--text-secondary);
  margin-bottom: 5px;
}

.input-group input,
.input-group select {
  width: 100%;
  padding: 9px 12px;
  background: var(--bg-glass);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-sm);
  color: var(--text-primary);
  font-size: 13px;
  font-family: inherit;
  font-weight: 500;
  transition: var(--transition);
  outline: none;
}

.input-group input:focus,
.input-group select:focus {
  border-color: var(--accent);
  box-shadow: 0 0 0 3px var(--accent-glow);
}

.input-group .unit {
  position: absolute;
  right: 10px;
  bottom: 9px;
  font-size: 11px;
  color: var(--text-dim);
  pointer-events: none;
}

/* Preset buttons */
.preset-row {
  display: flex;
  gap: 6px;
  margin-bottom: 12px;
}

.preset-btn {
  flex: 1;
  padding: 7px 8px;
  background: var(--bg-glass);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-sm);
  color: var(--text-secondary);
  font-size: 11px;
  font-weight: 500;
  cursor: pointer;
  transition: var(--transition);
  font-family: inherit;
}

.preset-btn:hover {
  background: rgba(74, 158, 255, 0.1);
  border-color: var(--accent);
  color: var(--accent);
}

.preset-btn.active {
  background: rgba(74, 158, 255, 0.15);
  border-color: var(--accent);
  color: var(--accent);
}

/* Cargo Item Form */
.cargo-form {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 10px;
}

.cargo-form .full-width {
  grid-column: 1 / -1;
}

/* Add button */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 6px;
  padding: 10px 18px;
  border: none;
  border-radius: var(--radius-sm);
  font-size: 13px;
  font-weight: 600;
  font-family: inherit;
  cursor: pointer;
  transition: var(--transition);
}

.btn-primary {
  background: linear-gradient(135deg, var(--accent), var(--accent-secondary));
  color: white;
  box-shadow: 0 4px 15px var(--accent-glow);
}

.btn-primary:hover {
  transform: translateY(-1px);
  box-shadow: 0 6px 20px var(--accent-glow);
}

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

.btn-secondary:hover {
  border-color: var(--accent);
  color: var(--accent);
}

.btn-danger {
  background: rgba(248, 113, 113, 0.1);
  border: 1px solid rgba(248, 113, 113, 0.2);
  color: var(--danger);
}

.btn-danger:hover {
  background: rgba(248, 113, 113, 0.2);
}

.btn-solve {
  width: 100%;
  padding: 14px;
  font-size: 14px;
  font-weight: 700;
  letter-spacing: 0.3px;
  background: linear-gradient(135deg, var(--accent), var(--accent-secondary));
  color: white;
  border: none;
  border-radius: var(--radius);
  cursor: pointer;
  transition: var(--transition);
  box-shadow: 0 4px 20px var(--accent-glow);
  position: relative;
  overflow: hidden;
}

.btn-solve::before {
  content: '';
  position: absolute;
  top: 0; left: -100%;
  width: 100%; height: 100%;
  background: linear-gradient(90deg, transparent, rgba(255,255,255,0.15), transparent);
  transition: 0.5s;
}

.btn-solve:hover::before {
  left: 100%;
}

.btn-solve:hover {
  transform: translateY(-2px);
  box-shadow: 0 8px 30px var(--accent-glow);
}

.btn-solve:disabled {
  opacity: 0.5;
  cursor: not-allowed;
  transform: none;
}

/* Cargo List */
.cargo-list {
  display: flex;
  flex-direction: column;
  gap: 8px;
  max-height: 250px;
  overflow-y: auto;
  margin-bottom: 12px;
}

.cargo-item {
  display: flex;
  align-items: center;
  gap: 10px;
  padding: 10px 12px;
  background: var(--bg-glass);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-sm);
  transition: var(--transition);
}

.cargo-item:hover {
  border-color: var(--border-glow);
}

.cargo-item .color-dot {
  width: 10px;
  height: 10px;
  border-radius: 50%;
  flex-shrink: 0;
}

.cargo-item .info {
  flex: 1;
  min-width: 0;
}

.cargo-item .name {
  font-size: 13px;
  font-weight: 600;
  white-space: nowrap;
  overflow: hidden;
  text-overflow: ellipsis;
}

.cargo-item .dims {
  font-size: 12px;
  color: var(--text-secondary);
  margin-top: 2px;
}

.cargo-item .qty {
  font-size: 12px;
  font-weight: 600;
  color: var(--accent);
  padding: 2px 8px;
  background: rgba(74, 158, 255, 0.1);
  border-radius: 10px;
}

.cargo-item .edit-btn {
  background: none;
  border: none;
  color: var(--text-dim);
  cursor: pointer;
  padding: 4px;
  font-size: 14px;
  line-height: 1;
  transition: var(--transition);
}

.cargo-item .edit-btn:hover {
  color: var(--accent);
}

.cargo-item .remove-btn {
  background: none;
  border: none;
  color: var(--text-dim);
  cursor: pointer;
  padding: 4px;
  font-size: 16px;
  line-height: 1;
  transition: var(--transition);
}

.cargo-item .remove-btn:hover {
  color: var(--danger);
}

/* Main content */
.main-content {
  position: relative;
  overflow: hidden;
  background: var(--bg-primary);
}

#viewer-container {
  width: 100%;
  height: 100%;
}

/* Overlay controls */
.viewer-overlay {
  position: absolute;
  top: 16px;
  right: 16px;
  display: flex;
  gap: 8px;
}

.overlay-btn {
  width: 36px;
  height: 36px;
  display: flex;
  align-items: center;
  justify-content: center;
  background: var(--bg-glass);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-sm);
  color: var(--text-secondary);
  cursor: pointer;
  font-size: 16px;
  transition: var(--transition);
  backdrop-filter: blur(10px);
}

.overlay-btn:hover,
.overlay-btn.active {
  border-color: var(--accent);
  color: var(--accent);
}

.overlay-btn.active {
  background: rgba(74, 158, 255, 0.15);
}

/* Debug tooltip */
.debug-tooltip {
  position: absolute;
  pointer-events: none;
  z-index: 20;
  background: rgba(10, 10, 26, 0.92);
  backdrop-filter: blur(12px);
  border: 1px solid var(--border-glow);
  border-radius: var(--radius-sm);
  padding: 10px 14px;
  font-size: 11px;
  line-height: 1.6;
  color: var(--text-primary);
  max-width: 260px;
  white-space: nowrap;
  box-shadow: 0 4px 20px rgba(0,0,0,0.5);
}

.debug-tooltip strong {
  color: var(--accent);
  font-size: 12px;
}

/* Result Panel (bottom overlay) */
.result-panel {
  position: absolute;
  bottom: 0;
  left: 0;
  right: 0;
  background: rgba(10, 10, 26, 0.9);
  backdrop-filter: blur(20px);
  border-top: 1px solid var(--border-color);
  padding: 16px 24px;
  transform: translateY(100%);
  transition: transform 0.4s cubic-bezier(0.4, 0, 0.2, 1);
  z-index: 5;
}

.result-panel.visible {
  transform: translateY(0);
}

.result-grid {
  display: flex;
  gap: 32px;
  align-items: center;
}

.result-metric {
  display: flex;
  flex-direction: column;
  gap: 4px;
}

.result-metric .label {
  font-size: 12px;
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 1px;
  color: var(--text-dim);
}

.result-metric .value {
  font-size: 22px;
  font-weight: 800;
  color: var(--accent);
  font-variant-numeric: tabular-nums;
}

.result-metric .value.success { color: var(--success); }
.result-metric .value.warning { color: var(--warning); }
.result-metric .value.danger { color: var(--danger); }

.result-bar {
  flex: 1;
  display: flex;
  flex-direction: column;
  gap: 6px;
}

.bar-label {
  display: flex;
  justify-content: space-between;
  font-size: 13px;
  color: var(--text-secondary);
}

.bar-track {
  height: 6px;
  background: var(--bg-glass);
  border-radius: 3px;
  overflow: hidden;
}

.bar-fill {
  height: 100%;
  border-radius: 3px;
  background: linear-gradient(90deg, var(--accent), var(--accent-secondary));
  transition: width 0.8s cubic-bezier(0.4, 0, 0.2, 1);
}

.bar-fill.warning {
  background: linear-gradient(90deg, var(--warning), #f59e0b);
}

.bar-fill.danger {
  background: linear-gradient(90deg, var(--danger), #ef4444);
}

/* Empty state */
.empty-state {
  position: absolute;
  top: 50%;
  left: 50%;
  transform: translate(-50%, -50%);
  text-align: center;
  color: var(--text-dim);
  pointer-events: none;
}

.empty-state .icon {
  font-size: 48px;
  margin-bottom: 12px;
  opacity: 0.5;
}

.empty-state p {
  font-size: 14px;
  font-weight: 500;
}

/* Color picker */
.color-picker-row {
  display: flex;
  gap: 6px;
  flex-wrap: wrap;
  margin-top: 4px;
}

.color-swatch {
  width: 24px;
  height: 24px;
  border-radius: 6px;
  cursor: pointer;
  border: 2px solid transparent;
  transition: var(--transition);
}

.color-swatch:hover {
  transform: scale(1.15);
}

.color-swatch.active {
  border-color: white;
  box-shadow: 0 0 8px var(--accent-glow);
}

/* Action row */
.action-row {
  display: flex;
  gap: 8px;
  margin-top: 10px;
}

.action-row .btn { flex: 1; }

/* Loading Spinner */
.spinner {
  display: inline-block;
  width: 18px;
  height: 18px;
  border: 2px solid rgba(255,255,255,0.3);
  border-top-color: white;
  border-radius: 50%;
  animation: spin 0.6s linear infinite;
  margin-right: 8px;
}

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

/* Responsive */
@media (max-width: 900px) {
  .app {
    grid-template-columns: 1fr;
    grid-template-rows: auto auto 1fr;
  }

  .sidebar {
    border-right: none;
    border-bottom: 1px solid var(--border-color);
    max-height: 45vh;
  }

  .header-stats { display: none; }
}

/* Animations */
@keyframes fadeIn {
  from { opacity: 0; transform: translateY(8px); }
  to { opacity: 1; transform: translateY(0); }
}

.cargo-item { animation: fadeIn 0.25s ease-out; }

/* Section subtitle */
.section-subtitle {
  font-size: 12px;
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 1px;
  color: var(--text-dim);
  margin-top: 14px;
  margin-bottom: 10px;
}

/* Checkbox row */
.checkbox-row {
  display: flex;
  gap: 16px;
  padding: 4px 0;
}

.checkbox-label {
  display: flex;
  align-items: center;
  gap: 6px;
  font-size: 12px;
  font-weight: 500;
  color: var(--text-secondary);
  cursor: pointer;
  user-select: none;
}

.checkbox-label input[type="checkbox"] {
  appearance: none;
  -webkit-appearance: none;
  width: 16px;
  height: 16px;
  background: var(--bg-glass);
  border: 1px solid var(--border-color);
  border-radius: 4px;
  cursor: pointer;
  transition: var(--transition);
  position: relative;
}

.checkbox-label input[type="checkbox"]:checked {
  background: var(--accent);
  border-color: var(--accent);
}

.checkbox-label input[type="checkbox"]:checked::after {
  content: '';
  position: absolute;
  left: 4px;
  top: 1px;
  width: 5px;
  height: 9px;
  border: solid white;
  border-width: 0 2px 2px 0;
  transform: rotate(45deg);
}

/* Badges in cargo list */
.badges {
  display: flex;
  gap: 4px;
  margin-top: 3px;
}

.badge {
  font-size: 11px;
  font-weight: 600;
  padding: 2px 6px;
  border-radius: 4px;
  text-transform: uppercase;
  letter-spacing: 0.3px;
}

.badge-warn {
  background: rgba(251, 191, 36, 0.15);
  color: var(--warning);
  border: 1px solid rgba(251, 191, 36, 0.25);
}

.badge-danger {
  background: rgba(248, 113, 113, 0.12);
  color: var(--danger);
  border: 1px solid rgba(248, 113, 113, 0.2);
}

.badge-info {
  background: rgba(56, 189, 248, 0.12);
  color: #38bdf8;
  border: 1px solid rgba(56, 189, 248, 0.2);
}

/* Metrics row (axle load, CoG, distribution) */
.metrics-row {
  display: flex;
  gap: 12px;
  margin-top: 12px;
  align-items: stretch;
}

.metric-card {
  display: flex;
  align-items: flex-start;
  gap: 8px;
  padding: 10px 12px;
  background: var(--bg-glass);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-sm);
  min-width: 0;
}

.metric-card-wide {
  flex: 1.5;
  flex-direction: column;
}

.metric-icon {
  font-size: 16px;
  color: var(--accent);
  line-height: 1;
  margin-top: 2px;
}

.metric-body {
  display: flex;
  flex-direction: column;
  gap: 2px;
  min-width: 0;
}

.metric-title {
  font-size: 12px;
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 0.8px;
  color: var(--text-dim);
}

.metric-value {
  font-size: 18px;
  font-weight: 800;
  color: var(--accent);
  font-variant-numeric: tabular-nums;
}

.axle-row {
  display: flex;
  align-items: baseline;
  gap: 4px;
}

.axle-value {
  font-size: 16px;
  font-weight: 800;
  color: var(--accent);
  font-variant-numeric: tabular-nums;
}

.axle-value.danger {
  color: var(--danger);
}

.axle-limit {
  font-size: 11px;
  color: var(--text-dim);
}

.bar-track-sm {
  height: 4px;
  margin-top: 4px;
}

/* Distribution mini bar chart */
.dist-chart {
  display: flex;
  gap: 3px;
  align-items: flex-end;
  height: 40px;
  width: 100%;
}

.dist-bar-col {
  flex: 1;
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 2px;
  height: 100%;
}

.dist-bar-track {
  flex: 1;
  width: 100%;
  background: rgba(74, 158, 255, 0.08);
  border-radius: 2px;
  position: relative;
  overflow: hidden;
  display: flex;
  align-items: flex-end;
}

.dist-bar-fill {
  width: 100%;
  background: linear-gradient(0deg, var(--accent), var(--accent-secondary));
  border-radius: 2px;
  transition: height 0.6s cubic-bezier(0.4, 0, 0.2, 1);
  min-height: 0;
}

.dist-label {
  font-size: 10px;
  color: var(--text-dim);
  font-weight: 600;
}

/* Unplaced items warning */
.unplaced-warning {
  padding: 10px 14px;
  background: rgba(248, 113, 113, 0.08);
  border: 1px solid rgba(248, 113, 113, 0.2);
  border-radius: var(--radius-sm);
  font-size: 12px;
  color: var(--danger);
  margin-top: 8px;
}

.unplaced-title {
  font-size: 12px;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 0.8px;
  margin-bottom: 6px;
  color: var(--danger);
}

.unplaced-row {
  display: flex;
  align-items: center;
  gap: 8px;
  padding: 3px 0;
  font-size: 13px;
}

.unplaced-name {
  font-weight: 600;
  color: var(--text-primary);
}

.unplaced-count {
  color: var(--text-dim);
  font-weight: 600;
}

.unplaced-reason {
  color: var(--danger);
  font-weight: 500;
  margin-left: auto;
  font-size: 12px;
}