diff --git a/apps/desktop/src/styles.css b/apps/desktop/src/styles.css
index 9ddd8c2f304..95eeebe29ac 100644
--- a/apps/desktop/src/styles.css
+++ b/apps/desktop/src/styles.css
@@ -386,12 +386,12 @@
       'Apple Color Emoji', 'Segoe UI Emoji', 'Segoe UI Symbol', 'Noto Color Emoji', emoji;
     /* Key caps always use the native UI face — never theme typography overrides. */
     --dt-font-kbd: -apple-system, BlinkMacSystemFont, 'SF Pro Text', 'Segoe UI', system-ui, sans-serif;
-    /* JetBrains Mono first — the face we bundle (@font-face above) and the
-       terminal's primary — so code/diff match the terminal on every platform
-       instead of drifting to a system Cascadia Code where it's installed. */
+    /* Menlo/Monaco first — Apple's native monospace faces — so code/diff read
+       in the system mono on macOS, with SF Mono and bundled Courier Prime as
+       fallbacks. */
     --dt-font-mono:
-      'JetBrains Mono', 'Cascadia Code', 'SF Mono', ui-monospace, Menlo, Consolas, monospace, 'Apple Color Emoji',
-      'Segoe UI Emoji', 'Segoe UI Symbol', 'Noto Color Emoji', emoji;
+      Menlo, Monaco, 'SF Mono', 'Courier Prime', monospace, 'Apple Color Emoji', 'Segoe UI Emoji', 'Segoe UI Symbol',
+      'Noto Color Emoji', emoji;
     --dt-base-size: 1rem;
     --dt-line-height: 1.5;
     --dt-letter-spacing: 0;
@@ -1549,6 +1549,13 @@ text-* variant utilities. */ .btn-arc {
   margin: 0 !important;
 }
 
+/* react-shiki nests its own `pre.shiki` inside our `.aui-shiki` Pre, so the
+   code card's `[&_pre]` padding lands on both and doubles the inset. The outer
+   Pre already carries the card's padding — zero the inner one. */
+[data-slot='aui_assistant-message-content'] .aui-md .aui-shiki .shiki {
+  padding: 0 !important;
+}
+
 [data-slot='aui_assistant-message-content'] .aui-md .aui-md-table {
   border-spacing: 0;
 }
diff --git a/apps/desktop/src/themes/presets.ts b/apps/desktop/src/themes/presets.ts
index 9cfb880c660..464381819f0 100644
--- a/apps/desktop/src/themes/presets.ts
+++ b/apps/desktop/src/themes/presets.ts
@@ -15,8 +15,7 @@ const SYSTEM_SANS =
   '"Segoe WPC", "Segoe UI", -apple-system, BlinkMacSystemFont, "SF Pro Text", "SF Pro Display", system-ui, sans-serif, ' +
   EMOJI_FALLBACK
 
-const SYSTEM_MONO =
-  '"Cascadia Code", "JetBrains Mono", "SF Mono", ui-monospace, Menlo, Monaco, Consolas, monospace, ' + EMOJI_FALLBACK
+const SYSTEM_MONO = 'Menlo, Monaco, "SF Mono", "Courier Prime", monospace, ' + EMOJI_FALLBACK
 
 export const DEFAULT_TYPOGRAPHY: DesktopThemeTypography = { fontSans: SYSTEM_SANS, fontMono: SYSTEM_MONO }
 
@@ -92,7 +91,7 @@ export const nousTheme: DesktopTheme = {
   },
   typography: {
     fontSans: SYSTEM_SANS,
-    fontMono: `"Courier Prime", ${SYSTEM_MONO}`,
+    fontMono: SYSTEM_MONO,
     fontUrl: 'https://fonts.googleapis.com/css2?family=Courier+Prime:wght@400;700&display=swap'
   }
 }