Custom css on admin area

[girtri]

Is it possible to add a custom css file in Magento 2 admin area (backend)?

If yes, what's the right way?

[Dmitry_Fedyuk]

How to add JavaScript / CSS / Less with a custom module: https://mage2.pro/t/34
How to add a stylesheet to a page after the layout has already been built: https://mage2.pro/t/149

[gerand]

Hello, I'm having problem with css in the backend magento, css does not load in the backend after installation, any suggestion of what this might be?