Allow only some files in subdirectories with .gitignore

So, the .gitignore works for me is the following:

# Ignore
lib/
src/
build/
static/**/*

# Allow
!static/css/bootstrap-styled.css
!static/css/main.css
!static/css/font-*.css
!static/font/*
!static/media/default.png
!static/robots.txt