diff --git a/.changeset/fix-quick-chat-stop-button-width.md b/.changeset/fix-quick-chat-stop-button-width.md
new file mode 100644
index 0000000000..60616f4b98
--- /dev/null
+++ b/.changeset/fix-quick-chat-stop-button-width.md
@@ -0,0 +1,5 @@
+---
+"@fusion/dashboard": patch
+---
+
+Fix the quick chat stop button rendering too narrow. It borrowed ChatView's `.chat-input-stop` styling, which sizes itself with `--chat-input-control-size` — a variable scoped to ChatView's composer and undefined in the quick chat DOM — collapsing the button toward its icon width. It is now pinned to the send button's square dimensions.
diff --git a/packages/dashboard/app/components/QuickChatFAB.css b/packages/dashboard/app/components/QuickChatFAB.css
index b8d4ea6cd7..9388fccbf4 100644
--- a/packages/dashboard/app/components/QuickChatFAB.css
+++ b/packages/dashboard/app/components/QuickChatFAB.css
@@ -784,6 +784,20 @@
   cursor: not-allowed;
 }
 
+/* The quick chat stop button reuses .chat-input-stop for its red appearance,
+   but that class sizes itself with --chat-input-control-size, a variable scoped
+   to ChatView's .chat-input-row and undefined in this DOM — which collapsed the
+   button toward its icon width. Pin it to the send button's square dimensions
+   using globally-scoped spacing tokens. The compound selector outranks the
+   single-class base and mobile rules from both stylesheets. */
+.quick-chat-send-btn.chat-input-stop {
+  width: calc(var(--space-lg) + var(--space-xl));
+  min-width: calc(var(--space-lg) + var(--space-xl));
+  height: calc(var(--space-lg) + var(--space-xl));
+  min-height: calc(var(--space-lg) + var(--space-xl));
+  border-radius: var(--radius-sm);
+}
+
 .quick-chat-attachment-previews {
   display: flex;
   gap: var(--space-xs);