For tasks you enjoy, write them yourself.

For instance, if you clicked on an n-bit adder,

you could see how it was recursively generated,

showing that it consists of a 1-bit adder combined with an (n-1)-bit adder.

I think that would be really interesting, but I just haven't had the time to actually do it.

https://github.com/mindChickey/circuit/tree/master/cirlisp

There is no documentation, but I think the design is worth a look.

The specific language doesn't matter much; using TypeScript to run it in the browser is a good choice.

As for a graphical interface for wires and gates—I don't think it's necessary;

Expressing it directly in code is more efficient..

I drew inspiration from the circuit simulator in SICP and a tool called Logisim,

and used Lisp to design a circuit simulation library.

The core concept was:

Each function could generate a circuit module,

that accepted multiple input lines—each consisting of multiple bits,

and produced a single output line, which also consisted of multiple bits.

For example, an adder would take two $n$-bit lines as input and output a single $n$-bit line.

Using this simulation library, I also built a simple CPU and implemented a factorial function using its machine language.

yet we are stuck suffering with the mainstream languages.