The documentation for CSS variables should clearly state the scope of variables about textual HOT 1 OPEN

import os
from pathlib import Path
from textual.app import App
from textual.css.parse import substitute_references
from textual.css.tokenize import tokenize, tokenize_values

class MyApp(App):
   def get_css_variables(self) -> dict[str, str]:
       """
       Dirty hack to add shared variables for the whole app
       """
       variables = super().get_css_variables()
       last_t = None
       current_variable_name = None
       css_path = os.path.dirname(os.path.realpath(__file__)) + "/tcss/variables.tcss"
       css_content = Path(css_path).read_text()
       variable_tokens = tokenize_values(variables)
       tokens = iter(substitute_references(tokenize(css_content, (css_path, None)), variable_tokens))
       for t in tokens:
           if not t:
               continue
           elif t.name == "variable_name":
               current_variable_name = t.value[1:-1]
           elif t.name == "variable_value_end":
               variables[current_variable_name] = last_t.value
           last_t = t
       return variables