Complete reference for row-span.

docs/styles/grid/row_span.md

@@ -1 +1,45 @@
 # Row-span
+
+The `row-span` style specifies how many rows a widget will span in a grid layout.
+
+## Syntax
+
+```sass
+row-span: <INTEGER>
+```
+
+## Example
+
+The example below shows a 4 by 4 grid where many placeholders span over several rows.
+
+Notice that grid cells are filled from left to right, top to bottom.
+After placing the placeholders `#p1`, `#p2`, `#p3`, and `#p4`, the next available cell is in the second row, fourth column, which is where the top of `#p5` is.
+
+=== "Output"
+
+    ```{.textual path="docs/examples/styles/row_span.py"}
+    ```
+
+=== "row_span.py"
+
+    ```py
+    --8<-- "docs/examples/styles/row_span.py"
+    ```
+
+=== "row_span.css"
+
+    ```css
+    --8<-- "docs/examples/styles/row_span.css"
+    ```
+
+## CSS
+
+```sass
+row-span: 3
+```
+
+## Python
+
+```py
+widget.styles.row_span = 3
+```