Based on the reading, What is the difference between Islamic law as it existed in classical times compared to Islamic law today?

Reading

In the overwhelming majority of the Islamic world, and in particular in its largest population centers, Islamic law does not form the comprehensive law of the state today, rather Islamic law governs only a few select areas that the government enforces, in particular family law, inheritance, divorce, marriage, what we might call law of personal status that most countries have a European style of criminal code. For instance, Egypt has a Napoleonic code. We might consider Bangladesh or Pakistan to be English common law countries with written constitutions that are interpreted by judges. It's only a fairly small slice of the Islamic world where Shari'a law forms the comprehensive law of the state. This is a modern innovation. In classical times of course, Islamic law was independent of imperial law or the law of the governing administration. If you look at this map, the countries that are in purple are those countries where Islamic law applies as a general legal system. Some of these countries are hard to categorize. Pakistan for instance is an English common law country, although it has a constitution that in principle establishes Shari'a law as the highest source of law over the constitution, Iran and Saudi Arabia even more so in that direction. Countries in yellow are countries where Islamic law only governs personal law, the law of personal status. We're talking about family law, divorce law, inheritance, paternity, child custody, these kinds of things. In the countries in green, Islamic law has no official status, that people can follow if they want as a personal matter, but the government is not going to enforce it. Countries in orange, typically are countries where they have one region such as Northern Nigeria or Aceh Province, Indonesia that operates under Shari'a law.