Here's the pandoc README:

```haskell {include="filter.hs" style="background-color: red"}
Foo:: Div -> Div
```

:::{include="filter.hs"}
:::


::: Theorem
test thm1
:::

:::{.Theorem #thm2}
test thm2
:::

:::{class="Theorem" id="thm3"}
test thm3
:::