94233: use actual CSS variables in theme

src/app/shared/sass-helper/css-variable.reducer.ts

@@ -0,0 +1,20 @@
+import { CSSVariableAction, CSSVariableActionTypes } from './css-variable.actions';
+
+export interface CSSVariablesState {
+  [name: string]: string;
+}
+
+const initialState: CSSVariablesState = Object.create({});
+
+export function cssVariablesReducer(state = initialState, action: CSSVariableAction): CSSVariablesState {
+  switch (action.type) {
+    case CSSVariableActionTypes.ADD: {
+      const variable = action.payload;
+      const t =  Object.assign({}, state, { [variable.name]: variable.value });
+      return t;
+    }
+    default: {
+      return state;
+    }
+  }
+}