fix: drop casing; absolutely ensure gtk.css and gtk-dark.css are the same

build.py

@@ -55,10 +55,7 @@ class BuildContext:
     tweaks: Tweaks
 
     def output_dir(self) -> str:
-        suffix = "light"
-        if self.flavor.dark:
-            suffix = "dark"
-        return f"{self.build_root}/{self.build_id()}-{suffix}"
+        return f"{self.build_root}/{self.build_id()}"
 
     def build_id(self) -> str:
         return f"{self.theme_name}-{self.flavor.identifier}-{self.accent.identifier}-{self.size}+{self.tweaks.id() or 'default'}"
@@ -118,8 +115,7 @@ def build(ctx: BuildContext):
         [
             "sassc",
             *SASSC_OPT,
-            # NOTE: This uses 'Dark' for the source, but 'dark' for the destination. This is intentional. Do !!NOT!! change it without consultation
-            f"{SRC_DIR}/main/gtk-3.0/gtk-Dark.scss",
+            f"{SRC_DIR}/main/gtk-3.0/gtk{ctx.apply_suffix(DARK_LIGHT)}.scss",
             f"{output_dir}/gtk-3.0/gtk-dark.css",
         ]
     )
@@ -137,8 +133,7 @@ def build(ctx: BuildContext):
         [
             "sassc",
             *SASSC_OPT,
-            # NOTE: This uses 'Dark' for the source, but 'dark' for the destination. This is intentional. Do !!NOT!! change it without consultation
-            f"{SRC_DIR}/main/gtk-4.0/gtk-Dark.scss",
+            f"{SRC_DIR}/main/gtk-4.0/gtk{ctx.apply_suffix(DARK_LIGHT)}.scss",
             f"{output_dir}/gtk-4.0/gtk-dark.css",
         ]
     )