Wordpress.org oEmbed Gist Plugin - text display alignment issue

Environment

• Wordpress 4.3.1
• oEmbed Gist Plugin version 2.0.0

The Problem

See this Sample Blog webpage - for some reason the texts have become "way-too-left-aligned", causing the texts towards the left edge not visible any more.

This problem did not exist before (texts used to display ok and all visible within the border) - I noticed this only about a couple of weeks ago - not sure if it's cause by some kind of updates / unknown factors. (Anyone got similar issues and how to resolve this?)

Here is a snapshot of the current problematic state:

via Chebli Mohamed