Selenium33
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A Vim-friendly Arsenik mod:
- 3 home-row mods per hand for Ctrl, Alt, Super
- 3 layer-tap keys under the thumbs: Shift/Backspace,
Navigation/Space, Symbol/Return

Selenium uses 4 layers (instead of 3 for Arsenik), which makes it a natural fit
for 34-key keyboards like the [Ferris][34].
[34]: https://github.com/pierrechevalier83/ferris
Extended Navigation
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- Vim-like navigation in all apps, with any OS layout
- super-comfortable Tab and Shift-Tab
- mouse emulation: previous / next and mouse scroll
- easy left-hand shortcuts

This Navigation layer has a few empty slots on purpose, so you can
add our own keys or layers.
NumRow >> NumPad
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In Symbol mode, pressing the left thumb key brings up the
NumRow layer:
- all digits are on the home row, in the order you already know
- the upper row helps with Shift-digit shortcuts
- the lower row has dash, comma, dot and slash signs to help with number / date
inputs

Even on keyboards that *do* have a physical number row, this NumRow
layer can be interesting to use in order to minimize finger movements further
more. And it makes it easier to mix symbols with numbers (e.g. `[0]`).
Implementations
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### Kanata

It turns out the `Atomic` mod can support all Selenium33 features smoothly.
You should definitely use `Atomic` and tweak it to your liking instead of using
this. :-)
### QMK
The QMK implementation is a bit different:
- it takes advantage of the 4 thumb keys
- the Navigation layer uses a mouse emulation on the left hand
In fact, this is what I ended up with for my beloved Ferris in the first place,
and Arsenik/Selenium is an attempt to fit most of this magic into my laptop keyboard.

```bash
# from the `qmk_firmware` root:
make ferris/0_2/bling:1dk:flash
```