[change] Xoa toan bo themes cu

- Thay doi themes cua Muan thanh theme cua gereksiz
- Fix lai color, font-size cho code
- Tang weight cho the main
[change] Xoa toan bo themes cu

- Thay doi themes cua Muan thanh theme cua gereksiz
- Fix lai color, font-size cho code
- Tang weight cho the main