#20: Adjust content styles in Simple course and editor
Merge pull request #21 from jaw4ik/master

#20: Adjust content styles (Not reviewed)
Revert "#20: Adjust content styles"
Merge pull request #22 from easygenerator/revert-21-master

Revert "#20: Adjust content styles"
Merge remote-tracking branch 'upstream/master'
Size of buttons in firefox was corrected