made the map area message more explicit

Author: DOSull

tiling-explorer-2.py

@@ -77,7 +77,16 @@ def _(mo):
 
 @app.cell(hide_code=True)
 def _(mo, pals, tile, tile_map_button, tiled_map, vars):
-    mo.stop(not tile_map_button.value, mo.md("### Click the **Tile map!** button to continue and to refresh the map after any design changes"))
+    _msg = "\n".join([
+        "## Click the **Tile map!** button to start", 
+        "## or to refresh the map",
+        "## after design changes",
+    ])
+    mo.stop(not tile_map_button.value, 
+            mo.md(_msg).style({"display": "flex", "height": "500px",
+                               "justify-content": "center",
+                               "align-items": "center",
+                               "text-align": "center"}))
     tiled_map.variables = {k: v for k, v in zip(tile.tiles.tile_id, vars.value)}
     tiled_map.colourmaps = {k: v for k, v in zip(vars.value, pals.value)}
     tiled_map.render(legend=False)