Add night_mode_lib as SCSS target

ts/deckoptions/BUILD.bazel

@@ -134,6 +134,7 @@ svelte_check(
         "*.svelte",
     ]) + [
         "//ts/sass:button_mixins_lib",
+        "//ts/sass:night_mode_lib",
         "//ts/sass/bootstrap",
         "@npm//@types/bootstrap",
         "@npm//@types/lodash-es",

ts/sass/BUILD.bazel

@@ -53,6 +53,14 @@ sass_library(
     visibility = ["//visibility:public"],
 )
 
+sass_library(
+    name = "night_mode_lib",
+    srcs = [
+        "night_mode.scss",
+    ],
+    visibility = ["//visibility:public"],
+)
+
 exports_files(
     ["_vars.scss"],
     visibility = ["//visibility:public"],