I'm surprised no one in this thread has mentioned Workflowy[0].
It is extremely minimal and elegant, does everything that you're looking for (on first glance), and is completely free. Not to be hyperbolic but the interface is ingenious in it's power and simplicity. Give it a shot.
It is extremely minimal and elegant, does everything that you're looking for (on first glance), and is completely free. Not to be hyperbolic but the interface is ingenious in it's power and simplicity. Give it a shot.
[0]: https://workflowy.com/basics/