Highlight tab selection and content visually a bit

[MichaIng]

So that it is better visible and also the end of a tabs content is clearer separated from following content. Below a relative simple example, using a light border and giving the selected button a background. The border and button edge radius can be adjusted, as well as the padding between content text and border. I thought as well to give the content some background, but that might be too aggressive.

[MichaIng]

Another suggestion, as I'm not happy with that border, so reducing the background brightness a little. This has also a slight blue+green colour touch. Downside is that images with white background will be brighter than the tab background.