/* ── Panel Designer ─────────────────────────────────────────────────── */
#panel-designer-section {
  margin-top: 32px;
  background: #fff;
  border: 1px solid #e2e8f0;
  border-radius: 16px;
  overflow: hidden;
}

.designer-header {
  padding: 20px 24px 0;
}

.designer-header h2 {
  font-size: 20px;
  font-weight: 700;
  color: #0f172a;
  margin-bottom: 4px;
}

.designer-header .designer-subtitle {
  font-size: 13px;
  color: #64748b;
  margin-bottom: 16px;
}

/* Metrics bar */
.designer-metrics {
  display: flex;
  gap: 12px;
  margin-bottom: 16px;
}

.metric-card {
  flex: 1;
  background: #f8fafc;
  border: 1px solid #e2e8f0;
  border-radius: 10px;
  padding: 12px 14px;
  text-align: center;
}

.metric-card .metric-label {
  font-size: 11px;
  text-transform: uppercase;
  letter-spacing: 0.05em;
  color: #64748b;
  margin-bottom: 2px;
}

.metric-card .metric-value {
  font-size: 22px;
  font-weight: 700;
  color: #0f172a;
}

.metric-card .metric-unit {
  font-size: 12px;
  color: #94a3b8;
  font-weight: 400;
}

.metric-card.highlight {
  background: #f0fdf4;
  border-color: #bbf7d0;
}

.metric-card.highlight .metric-value {
  color: #16a34a;
}

/* Toolbar */
.designer-toolbar {
  display: flex;
  gap: 8px;
  padding: 0 24px 12px;
  flex-wrap: wrap;
}

.designer-toolbar button {
  padding: 8px 16px;
  border: 1px solid #e2e8f0;
  border-radius: 8px;
  background: #fff;
  font-size: 13px;
  font-weight: 500;
  cursor: pointer;
  transition: all 0.15s;
  color: #334155;
}

.designer-toolbar button:hover {
  background: #f1f5f9;
  border-color: #cbd5e1;
}

.designer-toolbar button.primary {
  background: #3b82f6;
  color: #fff;
  border-color: #3b82f6;
}

.designer-toolbar button.primary:hover {
  background: #2563eb;
}

.designer-toolbar button.danger {
  color: #dc2626;
}

.designer-toolbar button.danger:hover {
  background: #fef2f2;
  border-color: #fecaca;
}

.designer-toolbar button.success {
  background: #15803d;
  color: #fff;
  border-color: #15803d;
}

.designer-toolbar button.success:hover {
  background: #166534;
}

.designer-toolbar button:disabled {
  opacity: 0.4;
  cursor: default;
}

.designer-toolbar .spacer {
  flex: 1;
}

/* Canvas container */
.designer-canvas-container {
  position: relative;
  width: 100%;
  background: #1a1a2e;
  cursor: crosshair;
}

.designer-canvas-container .loading-overlay {
  position: absolute;
  inset: 0;
  display: flex;
  align-items: center;
  justify-content: center;
  background: rgba(15, 23, 42, 0.85);
  color: #fff;
  font-size: 14px;
  z-index: 10;
}

.designer-canvas-container .loading-overlay .spinner-sm {
  width: 24px;
  height: 24px;
  border: 3px solid rgba(255,255,255,0.2);
  border-top-color: #fff;
  border-radius: 50%;
  animation: spin 0.8s linear infinite;
  margin-right: 10px;
}

/* Footer */
.designer-footer {
  padding: 12px 24px 16px;
  display: flex;
  align-items: center;
  gap: 8px;
}

.designer-footer .tip-icon {
  font-size: 14px;
}

.designer-footer p {
  font-size: 12px;
  color: #94a3b8;
  line-height: 1.4;
}

.designer-footer .disclaimer {
  font-size: 11px;
  color: #cbd5e1;
  margin-top: 4px;
}

/* Panel selection highlight */
.panel-selected-info {
  display: none;
  align-items: center;
  gap: 6px;
  padding: 6px 12px;
  background: #eff6ff;
  border: 1px solid #bfdbfe;
  border-radius: 6px;
  font-size: 12px;
  color: #1e40af;
}

.panel-selected-info.visible {
  display: flex;
}

/* Responsive */
@media (max-width: 600px) {
  .designer-metrics {
    flex-direction: column;
  }

  .designer-toolbar {
    padding: 0 16px 12px;
  }

  .designer-toolbar button {
    padding: 8px 12px;
    font-size: 12px;
  }

  .designer-header {
    padding: 16px 16px 0;
  }

  .designer-footer {
    padding: 12px 16px;
  }
}