Fix illegible code blocks: use light background to match Prism theme

The existing prism.css sets color:black on code elements. Dark
bg-stone-900 backgrounds made text invisible. Switched to bg-stone-50
with a border to work with the light Prism theme.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

sx/sxc/docs.sx

@@ -16,7 +16,7 @@
     children))
 
 (defcomp ~doc-code (&key language code)
-  (div :class "bg-stone-900 rounded-lg p-4 overflow-x-auto"
+  (div :class "bg-stone-50 border border-stone-200 rounded-lg p-4 overflow-x-auto"
     (pre :class "text-sm"
       (code :class (str "language-" (or language "lisp")) code))))
 

sx/sxc/examples.sx

@@ -12,7 +12,7 @@
   (div :class "border border-dashed border-stone-300 rounded p-4 bg-white" children))
 
 (defcomp ~example-source (&key code)
-  (div :class "bg-stone-900 rounded p-4 mt-3 overflow-x-auto"
+  (div :class "bg-stone-50 border border-stone-200 rounded p-4 mt-3 overflow-x-auto"
     (pre :class "text-sm"
       (code :class "language-lisp" code))))
 

sx/sxc/home.sx

@@ -9,8 +9,8 @@
     (p :class "text-lg text-stone-500 max-w-2xl mx-auto mb-12"
       "A hypermedia-driven UI engine that combines htmx's server-first philosophy "
       "with React's component model. All rendered via s-expressions over the wire.")
-    (div :class "bg-stone-900 rounded-lg p-6 text-left font-mono text-sm overflow-x-auto"
-      (pre :class "text-stone-300"
+    (div :class "bg-stone-50 border border-stone-200 rounded-lg p-6 text-left font-mono text-sm overflow-x-auto"
+      (pre
         (code :class "language-lisp"
           "(defcomp ~greeting (&key name)\n  (div :class \"p-4 rounded bg-violet-50\"\n    (h2 :class \"text-lg font-bold\"\n      (str \"Hello, \" name \"!\"))\n    (button\n      :sx-get \"/api/greet\"\n      :sx-target \"closest div\"\n      :sx-swap \"outerHTML\"\n      :class \"mt-2 px-4 py-2 bg-violet-600 text-white rounded\"\n      \"Refresh\")))")))))