ui: further style collapsible sidebar

src/globalStyles.tsx

@@ -34,51 +34,4 @@ export const GlobalStyles = createGlobalStyle`
     padding-left: 2.8em;
     overflow: initial;
   }
-
-  /* TODO: probably extract this */
-  .tree-view {
-    overflow-y: hidden;
-  }
-
-  .tree-view_item {
-    display: flex;
-    cursor: pointer;
-  }
-
-  .tree-view_item,
-  .tree-view_children > div {
-    padding: 4px 0;
-  }
-
-  .tree-view_children {
-    margin-left: 16px;
-    display: flex;
-    flex-direction: column;
-    align-items: flex-start;
-  }
-
-  .tree-view_children-collapsed {
-    height: 0px;
-  }
-
-  .tree-view_arrow {
-    cursor: pointer;
-    margin-right: 6px;
-    display: inline-block;
-    -webkit-user-select: none;
-    -moz-user-select: none;
-    -ms-user-select: none;
-    user-select: none;
-  }
-
-  .tree-view_arrow:after {
-    content: "▾";
-  }
-
-  .tree-view_arrow-collapsed {
-    -webkit-transform: rotate(-90deg);
-    -moz-transform: rotate(-90deg);
-    -ms-transform: rotate(-90deg);
-    transform: rotate(-90deg);
-  }
 `