Feat: Let base font size be inherited from surrounding text

This makes cookie consent font size be correctly inherited even on sites that use
10px root font size for easier calculations.

src/scss/_theme.scss

@@ -8,6 +8,7 @@
 // By using Spirit design tokens, all Spirit-based projects benefit from plug-and-play setup.
 
 @use '@tokens' as tokens;
+@use 'tools';
 
 // Stylelint and Prettier are clashing on long lines. Let's prefer Stylelint.
 /* prettier-ignore */
@@ -17,7 +18,7 @@
     // Typography
     // ==========
 
-    --lmcccm-p-base-font-size: var(--lmcccm-base-font-size, #{tokens.$font-size-base});
+    --lmcccm-p-base-font-size: var(--lmcccm-base-font-size, #{tools.rem2em(tokens.$font-size-base)});
     --lmcccm-p-font-family: var(--lmcccm-font-family, #{tokens.$font-family-default});
 
     //