separate utils from data
split components
WIP: reuse components and styles
WIP: apply styles to each components
WIP: Menu of Hints
WIP: apply new styles
remove old styles
add Settings
add component Definition
remove the dependency of semantic-ui
use static API
separate sentence from playground
undo every cutting before change sentence
update styles for cubes in multiple lines
transparent background with the sentence only
style tweak
clean up styles
clean up:

- separate UI and Book components,
- use index.js as default script for a dir
remove semantic-ui
layout pages horizontally