Using Quran, not only as a religion but also as a governmental system. A justice and public management way of Islam.
Opposite of secularism
Usually, justice system of Sharia law is based on "an eye for an eye" mentality.
All Islamic countries who is governed under Sharia law forcet their women to wear some type of head scarf or/and full (sometimes black) cover. They always have some types of execution.
They try to apply all the rules, law and regulations based on what Quran says and how their religious people comments on the Holy writings.
Example of such countries,
Saudi Arabia,
Iran,
Yemen,
Afganistan