As you probably noticed on a lot of websites these days, there is an engraved looking effect added to text, let me show you how to add that effect using CSS.
You are trying to install or open an app that didn't come from the Mac App Store but you got a message saying App can't be opened because it is from an unidentified developer. This is how you bypass it.
You will find out how to summarize cells that have a same color of the font, the red one in my case. Really useful when working with different types of specific data in Excel.
