I'm a bit perplexed here. Last night I answered the following question: Use a higher than 230px logo image with 2013 theme. I was surprised this morning to see that the question was put on hold due to be off topic.
This took me back to this question: Extending content width with twentyfourteen theme. I raised a flag for this question as off topic, and I even told the OP that CSS related questions are off topic. My flag was declined, and this is what @toscho told me in a comment to my comment left
It is not off-topic just because it is about CSS. Questions which require knowledge about core internals (like the structure of a core theme) are on-topic.
So, now my question is, the question I've answered about the twenty thirteen header, it is not " like the structure of a core theme" and "require knowledge about core internals"? This wasn't just a purely CSS question, because you have to change the custom header's function to achieve the proper resize as I stated in my answer. What makes this question to be more off topic that the twentyfourteen question which is purely CSS related. Frankly, I have recently did the exact same thing that the OP was asking, so I know it is just CSS involved.
I don't mind loosing the reputation when the question eventually gets closed, it is just a matter of consistency here. Either the twenty fouteen question must be closed, or the twenty thirteen question must be reopened