diff --git a/apps/desktop/src/renderer/styles/base.css b/apps/desktop/src/renderer/styles/base.css
index affc546f65..ab8131e4ca 100644
--- a/apps/desktop/src/renderer/styles/base.css
+++ b/apps/desktop/src/renderer/styles/base.css
@@ -2,6 +2,14 @@
   body {
     margin: 0;
   }
+  /* Chat disclosures already pair their full-row trigger with a semantic
+     activity icon and aria-expanded. Astryx's trailing chevron lands at the
+     far edge of the reading column, where repeated rows look like a stray
+     vertical control rail. Keep the disclosure interaction and semantics,
+     but suppress that redundant decorative indicator on chat rows only. */
+  .maka-chat-disclosure > button > span:last-child {
+    display: none;
+  }
 .detailPane {
     min-width: 0;
     min-height: 0;
diff --git a/packages/ui/src/__tests__/processing-block.test.tsx b/packages/ui/src/__tests__/processing-block.test.tsx
index 0d5a8b414b..a0ea4a7645 100644
--- a/packages/ui/src/__tests__/processing-block.test.tsx
+++ b/packages/ui/src/__tests__/processing-block.test.tsx
@@ -43,6 +43,7 @@ describe('ProcessingBlock disclosure wiring (#1307)', () => {
     }));
 
     assert.match(markup, /class="[^"]*astryx-collapsible[^"]*"/);
+    assert.match(markup, /class="[^"]*maka-chat-disclosure[^"]*"/);
     assert.match(markup, /<button[^>]*aria-expanded="false"[^>]*aria-controls="[^"]+"/);
     assert.match(markup, /class="[^"]*astryx-collapsible-content[^"]*"/);
     assert.doesNotMatch(markup, /data-trow="row"/);
@@ -116,6 +117,7 @@ describe('deep-thinking disclosure', () => {
     }));
 
     assert.match(markup, /class="[^"]*astryx-collapsible[^"]*"/);
+    assert.match(markup, /class="[^"]*maka-chat-disclosure[^"]*"/);
     assert.match(markup, /<button[^>]*aria-expanded="false"[^>]*aria-controls="[^"]+"/);
     const trigger = markup.match(/(<button[^>]*aria-expanded="false"[\s\S]*?<\/button>)/)?.[1];
     assert.ok(trigger, 'deep-thinking disclosure must expose a collapsed trigger');
diff --git a/packages/ui/src/chat-turn.tsx b/packages/ui/src/chat-turn.tsx
index 54c3d49984..864d4deb72 100644
--- a/packages/ui/src/chat-turn.tsx
+++ b/packages/ui/src/chat-turn.tsx
@@ -1001,7 +1001,7 @@ function ProcessingBlock(props: { entries: FoldedTimelineChild[] }) {
   const summary = summarizeProcessing(entries, { live: running, locale });
   return (
     <AstryxCollapsible
-      className="flex flex-col"
+      className="maka-chat-disclosure flex flex-col"
       data-processing="block"
       data-settled={settled ? 'true' : undefined}
       isOpen={disclosure.open}
@@ -1075,7 +1075,7 @@ function DeepThinking(props: { text: string; live: boolean; truncated?: boolean
   }, [displayed, props.live, open]);
   return (
     <AstryxCollapsible
-      className="flex flex-col"
+      className="maka-chat-disclosure flex flex-col"
       data-deep-thinking={props.live ? 'live' : undefined}
       isOpen={open}
       onOpenChange={setOpen}
diff --git a/packages/ui/src/tool-activity.tsx b/packages/ui/src/tool-activity.tsx
index e382966f38..d5bc621464 100644
--- a/packages/ui/src/tool-activity.tsx
+++ b/packages/ui/src/tool-activity.tsx
@@ -466,7 +466,7 @@ function ToolTrowGroup({ items }: { items: ToolActivityItem[] }) {
     : summarizeTrowTools(items, { locale });
   return (
     <AstryxCollapsible
-      className="flex flex-col"
+      className="maka-chat-disclosure flex flex-col"
       data-trow="group"
       data-settled={settled ? 'true' : undefined}
       isOpen={disclosure.open}
@@ -531,7 +531,7 @@ function ToolTrowRow({ item }: { item: ToolActivityItem }) {
   const rowLabel = item.intent ? formatToolIntent(item.intent) : resolveToolDisplayName(item, locale);
   return (
     <AstryxCollapsible
-      className="flex flex-col"
+      className="maka-chat-disclosure flex flex-col"
       data-trow="row"
       data-status={sandboxBlocked ? 'blocked' : item.status}
       data-settled={settled ? 'true' : undefined}