Solucionado:
Cita: How do I represent extended characters in CSS?
A CSS file can be in any encoding, so most of the time, specifying the right encoding will allow you to use any extended character directly in the CSS code. However, at time you may not be able to represent a given character in its raw form, you can then use the hexadecimal notation \HHH where HHH is the Unicode value of a given character.
To avoid confusion with the hexadecimal value and the following text (i.e. Is R\26D R+\26+D or R+\26D?) you may want to use a trailing space after the value. Any first space after the hexadecimal notation is ignored, therefore would "R\26 D" display correctly "R&D".
Example of CSS code with extended character in hexadecimal notation:
@import "main.css"
/* Translatable data */
arguments:before {
content: "Param\E8tres\0A:\0A";
font-weight: bold
}
Ejemplo, para el punto: 2022 en Unicode.
Content: 'Bla bla bla \2022 bla bla bla';