Modify Magento UI Library CSS

[azmaer]

Hello,

i almost understand how magento is working. I can change variables and others, but right now i have problem with Magento UI CSS library files. Usually i could overwrite every file but there is no way to overwrite UI files?

lib/web/css/source/lib/_navigation.less <- this UI file i wanted to copy and change in my template. so i take it to:

app/design/frontend/MyT/themename/web/css/source/lib

yet my page looks like without css. What am i missing?

[Dmitry_Fedyuk · Accepted solution]

There is no such possibility. 

Use your custom CSS rules to overweight the core CSS rules instead.

[azmaer]

Thank you for fast replay