Values of content() function

content() function: content() = content([text | before | after | first-letter ])

The content() function is called in the property string-set:
string-set: <name> content([text | before | after | first-letter ]);

For now, only content(text) is implemented. We need the other values:

before

The string value of the ::before pseudo-element, determined as if white-space: normal had been set.

after

The string value of the ::after pseudo-element, determined as if white-space: normal had been set.

The result we should get: content-after-correct.pdf

first-letter

The first letter of the element, as defined for the ::first-letter pseudo-element