diff --git a/src/components/SyntaxHighlight.tsx b/src/components/SyntaxHighlight.tsx
index e89316e..2cbe4a4 100644
--- a/src/components/SyntaxHighlight.tsx
+++ b/src/components/SyntaxHighlight.tsx
@@ -29,42 +29,39 @@ export function SyntaxHighlight({
 }: SyntaxHighlightProps) {
   const { html, loading, error } = useHighlightedCode(code, language);
 
+  // Use consistent wrapper structure for all states to avoid size jumps
+  const wrapperClasses = cn(
+    "shiki-container overflow-x-auto max-w-full [&_pre]:!bg-transparent [&_pre]:!m-0 [&_code]:text-xs [&_code]:font-mono",
+    showLineNumbers && "line-numbers",
+    className,
+  );
+
   // Loading state - show code without highlighting
   if (loading) {
     return (
-      <pre
-        className={cn(
-          "shiki-loading overflow-x-auto max-w-full font-mono text-xs",
-          className,
-        )}
-      >
-        <code className="text-foreground/70">{code}</code>
-      </pre>
+      <div className={cn(wrapperClasses, "shiki-loading")}>
+        <pre className="!bg-transparent !m-0">
+          <code className="text-foreground/70">{code}</code>
+        </pre>
+      </div>
     );
   }
 
   // Error state - fallback to plain code
   if (error || !html) {
     return (
-      <pre
-        className={cn(
-          "overflow-x-auto max-w-full font-mono text-xs",
-          className,
-        )}
-      >
-        <code>{code}</code>
-      </pre>
+      <div className={wrapperClasses}>
+        <pre className="!bg-transparent !m-0">
+          <code>{code}</code>
+        </pre>
+      </div>
     );
   }
 
   // Render highlighted HTML
   return (
     <div
-      className={cn(
-        "shiki-container overflow-x-auto max-w-full [&_pre]:!bg-transparent [&_code]:text-xs [&_code]:font-mono",
-        showLineNumbers && "line-numbers",
-        className,
-      )}
+      className={wrapperClasses}
       dangerouslySetInnerHTML={{ __html: html }}
     />
   );
diff --git a/src/components/nostr/kinds/RepositoryFilesSection.tsx b/src/components/nostr/kinds/RepositoryFilesSection.tsx
index af934af..01130b9 100644
--- a/src/components/nostr/kinds/RepositoryFilesSection.tsx
+++ b/src/components/nostr/kinds/RepositoryFilesSection.tsx
@@ -97,23 +97,9 @@ export function RepositoryFilesSection({
     );
   }
 
-  // Error state
+  // Error state - silently hide section
   if (treeError) {
-    return (
-      <section className={cn("flex flex-col gap-4", className)}>
-        <h2 className="text-xl font-semibold flex items-center gap-2">
-          <FolderGit2 className="size-5" />
-          Files
-        </h2>
-        <div className="flex items-start gap-3 p-4 bg-destructive/10 border border-destructive/20 rounded text-sm">
-          <AlertCircle className="size-5 text-destructive flex-shrink-0 mt-0.5" />
-          <div className="flex flex-col gap-1">
-            <p className="font-medium">Unable to load repository files</p>
-            <p className="text-muted-foreground text-xs">{treeError.message}</p>
-          </div>
-        </div>
-      </section>
-    );
+    return null;
   }
 
   // No tree available
@@ -147,8 +133,22 @@ export function RepositoryFilesSection({
         <div className="border border-border rounded max-h-96 overflow-auto bg-muted/20">
           {selectedFile ? (
             contentLoading ? (
-              <div className="p-4">
-                <Skeleton className="h-48" />
+              <div className="relative">
+                <div className="sticky top-0 bg-muted/80 backdrop-blur-sm px-3 py-1.5 border-b border-border/50 flex items-center justify-between">
+                  <span className="text-xs font-mono text-muted-foreground truncate">
+                    {selectedFile.path}
+                  </span>
+                </div>
+                <div className="p-3 space-y-2">
+                  <Skeleton className="h-3 w-3/4" />
+                  <Skeleton className="h-3 w-1/2" />
+                  <Skeleton className="h-3 w-5/6" />
+                  <Skeleton className="h-3 w-2/3" />
+                  <Skeleton className="h-3 w-4/5" />
+                  <Skeleton className="h-3 w-1/3" />
+                  <Skeleton className="h-3 w-3/4" />
+                  <Skeleton className="h-3 w-1/2" />
+                </div>
               </div>
             ) : contentError ? (
               <div className="flex items-start gap-3 p-4 text-sm">
diff --git a/src/components/ui/FileTreeView.tsx b/src/components/ui/FileTreeView.tsx
index 748a43a..46a0615 100644
--- a/src/components/ui/FileTreeView.tsx
+++ b/src/components/ui/FileTreeView.tsx
@@ -153,7 +153,7 @@ function TreeNode({
   selectedPath,
   depth,
 }: TreeNodeProps) {
-  const [isOpen, setIsOpen] = useState(depth === 0);
+  const [isOpen, setIsOpen] = useState(false);
   const isSelected = selectedPath === path;
 
   const handleClick = () => {
diff --git a/src/lib/shiki.ts b/src/lib/shiki.ts
index bc6c955..78ac8ce 100644
--- a/src/lib/shiki.ts
+++ b/src/lib/shiki.ts
@@ -11,8 +11,8 @@ let highlighterPromise: Promise<HighlighterCore> | null = null;
 const loadedLanguages = new Set<string>();
 
 /**
- * Grimoire dark theme matching current minimalistic Prism styles
- * Uses muted colors with primary accent for keywords/functions
+ * Grimoire dark theme - minimalistic grayscale with semantic colors
+ * Uses muted grays for syntax with color only for diff semantics
  */
 const grimoireTheme: ThemeRegistration = {
   name: "grimoire-dark",
@@ -32,7 +32,7 @@ const grimoireTheme: ThemeRegistration = {
       scope: ["string", "string.quoted"],
       settings: { foreground: "#9ca3af" },
     },
-    // Keywords, operators - primary color
+    // Keywords, operators - emphasized gray
     {
       scope: [
         "keyword",
@@ -42,14 +42,14 @@ const grimoireTheme: ThemeRegistration = {
         "keyword.operator",
         "keyword.control",
       ],
-      settings: { foreground: "#a855f7" },
+      settings: { foreground: "#d4d4d4" },
     },
-    // Functions, methods - primary bold
+    // Functions, methods - foreground bold
     {
       scope: ["entity.name.function", "support.function", "meta.function-call"],
-      settings: { foreground: "#a855f7", fontStyle: "bold" },
+      settings: { foreground: "#e5e5e5", fontStyle: "bold" },
     },
-    // Classes, types - primary bold
+    // Classes, types - foreground bold
     {
       scope: [
         "entity.name.class",
@@ -57,9 +57,9 @@ const grimoireTheme: ThemeRegistration = {
         "support.class",
         "support.type",
       ],
-      settings: { foreground: "#a855f7", fontStyle: "bold" },
+      settings: { foreground: "#e5e5e5", fontStyle: "bold" },
     },
-    // Numbers, constants - primary
+    // Numbers, constants - emphasized gray
     {
       scope: [
         "constant",
@@ -67,7 +67,7 @@ const grimoireTheme: ThemeRegistration = {
         "constant.language",
         "constant.character",
       ],
-      settings: { foreground: "#a855f7" },
+      settings: { foreground: "#d4d4d4" },
     },
     // Variables, parameters - foreground
     {
@@ -91,7 +91,7 @@ const grimoireTheme: ThemeRegistration = {
     // Tags (HTML/JSX)
     {
       scope: ["entity.name.tag", "support.class.component"],
-      settings: { foreground: "#a855f7" },
+      settings: { foreground: "#d4d4d4" },
     },
     // JSON keys
     {
@@ -124,7 +124,7 @@ const grimoireTheme: ThemeRegistration = {
     // Markdown headings
     {
       scope: ["markup.heading", "entity.name.section"],
-      settings: { foreground: "#a855f7", fontStyle: "bold" },
+      settings: { foreground: "#e5e5e5", fontStyle: "bold" },
     },
     // Markdown bold/italic
     {
@@ -138,7 +138,7 @@ const grimoireTheme: ThemeRegistration = {
     // Markdown links
     {
       scope: ["markup.underline.link"],
-      settings: { foreground: "#a855f7" },
+      settings: { foreground: "#93c5fd" },
     },
   ],
 };
@@ -277,6 +277,8 @@ const CORE_LANGUAGES = [
   "json",
   "diff",
   "bash",
+  "rust",
+  "markdown",
 ] as const;
 
 /**
@@ -303,6 +305,8 @@ export async function getHighlighter(): Promise<HighlighterCore> {
         import("shiki/langs/json.mjs"),
         import("shiki/langs/diff.mjs"),
         import("shiki/langs/bash.mjs"),
+        import("shiki/langs/rust.mjs"),
+        import("shiki/langs/markdown.mjs"),
       ],
       engine: createOnigurumaEngine(import("shiki/wasm")),
     }).then((hl) => {