# A slightly less toy example

Most applications require a little more than a button on a page. Lets build a slightly more complex example - a Fahrenheit to Celsius converter:

![image](images/tutorial-1.png)

Here's the source code:

```python
-8<- "tutorial1/tutorial/app.py"
```

This example shows off some more features of Toga's Pack style engine. In this example app, we've set up an outer box that stacks vertically; inside that box, we've put 2 horizontal boxes and a button.

Since there's no width styling on the horizontal boxes, they'll try to fit the widgets they contain into the available space. The `TextInput` widgets have a style of `flex=1`, but the `Label` widgets have a fixed width; as a result, the `TextInput` widgets will be stretched to fit the available horizontal space. The `margin_left` style ensures that the `TextInputs` are aligned, and the `gap` style adds spacing between all the widgets.
