It is possible to block https sites on a URL-by-URL basis, but to do this you must use SSL Inspection (often called HTTPS inspection, or Man-in-the-middle / MitM).
Many proxies support this, it has a few deployment issues, the main one being that client computers must trust the SSL certificate that is used by the proxy to sign the new certificates that it creates (one per site). This requires adding that certificate to the trusted root store (and potentially other certificate stores, such as Firefox cert store) on the client computers / devices.
There may also be privacy issues and local jurisdiction issues about what is legal in your jurisdiction, so SSL inspection is not to be done lightly.
Once you are inspecting https traffic, then URL blocking is similar to the case for http.
Our product WinGate supports SSL inspection (need an enterprise license). Other products do as well, such as squid.
Disclaimer: I work for Qbik who are the authors of WinGate