fix: #229 disable light code theme

app/styles/prism.scss

@@ -120,33 +120,3 @@
     cursor: help;
   }
 }
-
-@mixin light {
-  .markdown-body pre {
-    filter: invert(1) hue-rotate(90deg) brightness(1.3);
-  }
-}
-
-@mixin dark {
-  .markdown-body pre {
-    filter: none;
-  }
-}
-
-:root {
-  @include light();
-}
-
-.light {
-  @include light();
-}
-
-.dark {
-  @include dark();
-}
-
-@media (prefers-color-scheme: dark) {
-  :root {
-    @include dark();
-  }
-}