One possible solution is to use purely CSS, so there's no need for for hacks like `layerList.classList.add("iconLayerList")`. The below CSS works for the above simple case (more complex selector might be necessary with complex maps): ``` div[title=Layers] calcite-icon { background-image: url('https://i.imgur.com/ESUiDwT.png'); background-repeat: no-repeat; background-size: 20px; background-position: center; } ``` JS part stays unchanged: ``` const layerListExpand = new Expand({ view: view, expandTooltip: "Layers", expandIcon: '', content: new LayerList({ view: view, }) }); view.ui.add(layerListExpand, "top-right"); ```