* change name of css classes to lowercase

* minor formating changes

* fix button name

* add button for intro def download

* add submodule

* Upravená HP, přejmenovaná fáze Define a další drobnosti

* repossition main logo

* make borders and boxes responsive

* change main logo location, change sizes of texts, and changes in grid cards

* reformat main page

* fix button name

* add button for intro def download

* add submodule

* Upravená HP, přejmenovaná fáze Define a další drobnosti

* repossition main logo

* make borders and boxes responsive

* change main logo location, change sizes of texts, and changes in grid cards

* reformat main page