Run button is not useable for users on mobile devices

[GuillaumeGomez]

Currently, the run button is only displayed when the mouse cursor hovers the code block, preventing users without a mouse cursor to see the button. However, having the run button displayed all the time over the code isn't great either. An alternative would be to reduce its size and put it into its own line.

What do you think?

cc @jsha

[jsha]

It actually is usable - I just tested on both Android Chrome and iOS Safari, and tapping the code block shows the Run button. I believe those browsers effectively treat a top as toggling the `:hover` state. There's still a bit of a problem with discoverability - how do you know to tap on the code block? But the same is true on a browser with a pointing device. How do you know to hover? Overall I think the status quo is okay, since the feature is usable on mobile but not obtrusive.

[GuillaumeGomez]

What do you think about adding this icon over the code block instead of on top? That would make it easier to add a "show hidden lines" button too.