app/helpers/application_helper.rb

@@ -190,7 +190,8 @@ module ApplicationHelper
         is_open: right_sidebar_showing,
         initial_width: right_panel_width,
         min_width: right_panel_min_width,
-        max_width: right_panel_max_width
+        max_width: right_panel_max_width,
+        overflow: right_sidebar_showing ? "auto" : "hidden"
       },
       content_max_width: content_max_width
     }

app/javascript/controllers/sidebar_controller.js

@@ -30,6 +30,7 @@ export default class extends Controller {
     this.contentTarget.style.maxWidth = `${this.#contentMaxWidth()}px`;
     this.leftPanelTarget.style.width = `${this.#leftPanelWidth()}px`;
     this.rightPanelTarget.style.width = `${this.#rightPanelWidth()}px`;
+    this.rightPanelTarget.style.overflow = this.#rightPanelOverflow();
   }
 
   #leftPanelWidth() {
@@ -52,6 +53,14 @@ export default class extends Controller {
     return 0;
   }
 
+  #rightPanelOverflow() {
+    if (this.rightPanelOpen) {
+      return "auto";
+    }
+
+    return "hidden";
+  }
+
   #contentMaxWidth() {
     if (!this.leftPanelOpen && !this.rightPanelOpen) {
       return 1024;

app/views/layouts/application.html.erb

@@ -67,7 +67,7 @@
 
     <%# AI chat sidebar %>
     <%= tag.div id: "chat-container",
-                style: "width: #{sidebar_config.dig(:right_panel, :initial_width)}px",
+                style: "width: #{sidebar_config.dig(:right_panel, :initial_width)}px; overflow: #{sidebar_config.dig(:right_panel, :overflow)}",
                 class: class_names("flex flex-col justify-between shrink-0 transition-all duration-300"),
                 data: { controller: "chat hotkey", sidebar_target: "rightPanel", turbo_permanent: true } do %>