Designed and tested on Windows 10 and macOS. Not tested, but it should also work for Linux.
This typora theme is inspired by the Gitbook document style. It features three variants: Azure, Slate and Teal. The Gitbook theme was designed with great attention to detail - modifying nearly all parts of the UI. This includes Windows unibody views.
Download the zipped project package here and un-zip it.
Copy the gitbook-azure.css, gitbook-slate.css and gitbook-teal.css file as well as the gitbook folder to your Typora theme library.
Launch or restart Typora and choose Gitbook Azure, Gitbook Slate, Gitbook Teal from the theme menu.