MenuList UX/UI improvements (#486)

Author: dalthviz

src/panel_material_ui/widgets/List.jsx

@@ -116,7 +116,28 @@ export function render({model}) {
             bgcolor: isActive ? (
               `rgba(var(--mui-palette-${color}-mainChannel) / var(--mui-palette-action-selectedOpacity))`
             ) : "inherit",
-            borderLeft: `3px solid var(--mui-palette-${color}-main)`
+            borderLeft: `6px solid var(--mui-palette-${color}-main)`,
+            ".MuiListItemText-root": {
+              ".MuiTypography-root.MuiListItemText-primary": {
+                fontWeight: "bold"
+              }
+            }
+          },
+          "&.MuiListItemButton-root.Mui-focusVisible": {
+            borderLeft: isActive ? `6px solid var(--mui-palette-${color}-main)` : "3px solid var(--mui-palette-secondary-main)",
+            borderTop: "3px solid var(--mui-palette-secondary-main)",
+            borderRight: "3px solid var(--mui-palette-secondary-main)",
+            borderBottom: "3px solid var(--mui-palette-secondary-main)",
+            bgcolor: isActive ? (
+              `rgba(var(--mui-palette-${color}-mainChannel) / var(--mui-palette-action-selectedOpacity))`
+            ) : "inherit"
+          },
+          "&.MuiListItemButton-root:hover": {
+            ".MuiListItemText-root": {
+              ".MuiTypography-root.MuiListItemText-primary": {
+                textDecoration: "underline"
+              }
+            }
           }
         }}
       >