changes for night theme

app/src/main/res/drawable/shape_transparent.xml

app/src/main/res/drawable/shape_transparent_black.xml

...n/res/drawable/shape_transparent_black_bottom_rounded.xml

...main/res/drawable/shape_transparent_black_top_rounded.xml

...rc/main/res/drawable/shape_transparent_bottom_rounded.xml

app/src/main/res/drawable/shape_transparent_top_rounded.xml

app/src/main/res/layout/fragment_learning_page.xml

app/src/main/res/layout/fragment_settings_page.xml

app/src/main/res/layout/fragment_stats_page.xml

app/src/main/res/values-night/themes.xml

app/src/main/res/values/themes.xml