/* Element Tree & Properties Panel */
.element-tree, .properties-panel { padding: 16px; }
.element-item { padding: 10px; border-radius: 6px; cursor: pointer; transition: background 0.2s; }
.element-item:hover { background: #f3f4f6; }
.element-item.active { background: #dbeafe; color: #1e40af; font-weight: 500; }
.empty-state { text-align: center; padding: 40px; color: #9ca3af; }
.empty-state svg { margin: 0 auto 16px; opacity: 0.3; }
.empty-state p { margin-bottom: 4px; }
.empty-state small { font-size: 12px; color: #d1d5db; }