Media queries

I don't know how wide the page is. `window.matchMedia("(min-width: 800px)")` is not working. :^(

This should be green if we are correctly ignoring `@media` rules that do not apply.

This should be green if we are correctly applying `@media screen`.

This should be green if the window is at least 400px wide.

This should be green if the window is at least 400px wide, and we understand range syntax.

This should be green if the window is at most 1000px wide.

This should be green if the window is at most 1000px wide, and we understand range syntax.

This should be green if the window is between 400px and 1000px wide.

This should be green if the window is between 400px and 1000px wide, and we understand range syntax.

This should be green if we detected the `color` feature.

This should be green if we detected the `color` feature and we understand `not`.

This should be green if we detected the `color` feature and a deeply nested query: `(color) or ((color) and ((color) or (color) or (not (color))))`.

## Relative lengths

This should be green if the window is wider than 80em.

This should be green if the window is taller than it is wide.

## Ratio

This should be green if the viewport aspect-ratio is less than 4/3. (So, less wide than a 4:3 ratio.)

This should be green if the viewport aspect-ratio is at least 2. (So, at least twice as wide as it is tall.)

This should be green if the viewport aspect-ratio is less than 0.5. (So, at least twice as tall as it is wide.)