I don't know why, but I dislike this error box.
Maybe do something like with other containers:
Code:
------------
|`TITLE````|
___________
|``````````|
|`CONTENT``|
|``````````|
Where title is "Error" or "Warning" with dark red background and black frame, and content is error content with light red and black frame.
Well, it's only my thought. "Keep Developing."