In Apex 5.0.3 I have a Form with a couple of fields "Display Image".

I would like this image to be scaled to its parent container.
I have tried adding:
<style type="text/css">
#P14_IMAGE {
width: 50px;
border-style: solid;
border-width: 1px;
}
</style>

But this does not work :

Note that images are cropped -see original image below-:

How can I make the image be adjusted/scaled to use 100% of its parent container?