Recently I wrote about handling the rendering exceptions in Sitecore in the post from Novemver 15th.
Last week I have updated the styling for them:

• Now error messages should look the same way on any website you install the package
• The css classes became more unique now so won’t conflict with any classes of your website
• The “expand” button finally well-styled!
• Exception types are moved to separate assembly and package so you can use them in any project of your solution without adding Sitecore website specific files.

I have attached new screen-shots to the original blog post.
If you are using this package, you can simply run

Update-Package Helpfulcore.RenderingExceptions

Say “yes” if nuget prompts you to override the .cshtml files (if you didn’t style them completely your way).

Enjoy!