diff --git a/README.md b/README.md
index 5063211..b493c07 100644
--- a/README.md
+++ b/README.md
@@ -267,7 +267,9 @@ The Pico 2 W onboard LED reports the overall Bluetooth state:
 
 ### Joy-Con 2 player arrangement
 
-In Controller Studio, use **Joy-Con 2 default mode** and **Apply default mode**.
+In Controller Studio, open **Adapter settings** in the top bar, then use
+**Joy-Con 2 default mode** and **Apply default mode**. Closing the settings
+dialog preserves unapplied selections and does not change your profile draft.
 This is a real adapter-wide setting, separate from the artwork preview:
 
 - **Paired:** ready opposite halves form one player and use their L+R bank.
diff --git a/src/switch_pico_bridge/web/profile_editor.css b/src/switch_pico_bridge/web/profile_editor.css
index 018892c..1557a04 100644
--- a/src/switch_pico_bridge/web/profile_editor.css
+++ b/src/switch_pico_bridge/web/profile_editor.css
@@ -600,10 +600,14 @@ input[type="range"] { width: 100%; accent-color: var(--blue); }
 .curve-controls output { float: right; color: var(--ink); }
 .curve-controls input[type="range"] { display: block; margin-top: 8px; }
 .copy-side { min-height: 34px; margin-top: auto; padding-block: 6px; }
-.copy-dialog { width: min(440px, calc(100% - 28px)); padding: 24px; color: var(--ink); border: 1px solid var(--line); border-radius: 18px; background: var(--surface-solid); box-shadow: var(--shadow); }
-.copy-dialog::backdrop { background: rgba(2, 5, 13, 0.76); }
+.copy-dialog, .adapter-settings-dialog { width: min(440px, calc(100% - 28px)); padding: 24px; color: var(--ink); border: 1px solid var(--line); border-radius: 18px; background: var(--surface-solid); box-shadow: var(--shadow); }
+.copy-dialog::backdrop, .adapter-settings-dialog::backdrop { background: rgba(2, 5, 13, 0.76); }
 .copy-dialog h3 { margin-bottom: 18px; }
 .dialog-actions { display: flex; justify-content: flex-end; gap: 9px; margin-top: 22px; }
+.adapter-settings-dialog { width: min(580px, calc(100% - 28px)); max-height: calc(100dvh - 28px); overflow-y: auto; }
+.adapter-settings-heading { display: flex; align-items: center; justify-content: space-between; gap: 16px; }
+.adapter-settings-heading .button { flex: 0 0 auto; min-height: 44px; }
+.adapter-settings-dialog .joycon-mode { margin-top: 20px; padding-bottom: 0; border-bottom: 0; }
 @media (max-width: 1120px) {
   .workspace { grid-template-columns: 250px minmax(0, 1fr); }
   .profile-list { grid-template-columns: 1fr; }
@@ -615,8 +619,10 @@ input[type="range"] { width: 100%; accent-color: var(--blue); }
   .editor-header { align-items: flex-start; }
 }
 @media (max-width: 780px) {
-  .topbar { position: relative; min-height: 76px; }
+  .topbar { position: relative; min-height: 76px; flex-wrap: wrap; gap: 12px; }
   .topbar-meta > p { display: none; }
+  .topbar-meta { width: 100%; justify-content: space-between; gap: 12px; }
+  .topbar-meta .adapter-settings-button { flex: 0 0 auto; min-height: 44px; }
   .connection { max-width: 52%; }
   .workspace { display: block; width: min(100% - 24px, 700px); margin-top: 14px; }
   .sidebar { position: relative; top: auto; margin-bottom: 18px; max-height: none; overflow: visible; scrollbar-gutter: auto; }
diff --git a/src/switch_pico_bridge/web/profile_editor.html b/src/switch_pico_bridge/web/profile_editor.html
index dbcd5ae..74ca4ba 100644
--- a/src/switch_pico_bridge/web/profile_editor.html
+++ b/src/switch_pico_bridge/web/profile_editor.html
@@ -23,6 +23,7 @@
         <span class="connection-dot"></span>
         <span id="connectionText">Connecting to adapter…</span>
       </div>
+      <button class="button button-secondary adapter-settings-button" id="adapterSettingsButton" type="button" aria-haspopup="dialog" aria-controls="adapterSettingsDialog">Adapter settings</button>
     </div>
   </header>
 
@@ -39,30 +40,6 @@
       <select id="identitySelect" class="select"></select>
       <p class="field-help">The default applies when a controller has no dedicated layout.</p>
 
-      <section class="joycon-mode" aria-labelledby="joyconModeTitle">
-        <p class="eyebrow">Adapter-wide setting</p>
-        <h3 id="joyconModeTitle">Joy-Con 2 default mode</h3>
-        <label class="field-label" for="joyconModeSelect">Default arrangement</label>
-        <select id="joyconModeSelect" class="select" aria-describedby="joyconModeHelp joyconModeStatus" disabled>
-          <option value="paired">Paired · L + R together</option>
-          <option value="individual">Individual · separate players</option>
-        </select>
-        <p class="field-help">Saved on the adapter; changing it applies live and clears temporary joins/splits. Not an artwork preview.</p>
-        <details class="joycon-mode-help">
-          <summary>Controller shortcut &amp; profile banks</summary>
-          <div id="joyconModeHelp">
-            <p><strong>Paired:</strong> L + R share one player and a separate L+R profile bank. Unmatched halves stay separate.</p>
-            <p><strong>Individual:</strong> each half is a sideways player using its own solo bank. Choose the L or R profile owner to edit it.</p>
-            <p><strong>Join / split this pair:</strong> hold <strong>ZL + Minus</strong> on the left and <strong>ZR + Plus</strong> on the right for <strong>2 seconds</strong>. A short pulse confirms success. Release all four buttons before using it again.</p>
-            <p>The shortcut affects only those halves and overrides this default until either disconnects. Other Joy-Cons are unchanged. Each half's complete two-button chord is reserved until both buttons release, even while waiting for the other half. Ambiguous solo selections do not join.</p>
-            <p>All saved banks and unsaved profile drafts are kept. Your chosen owner does not change automatically.</p>
-            <p>Saved preference is not a live pairing report. A pair waits for its L+R bank to be ready; the diagram and live playtest report the actual arrangement.</p>
-          </div>
-        </details>
-        <button class="button button-secondary" id="applyJoyconModeButton" type="button" disabled>Apply default mode</button>
-        <p class="joycon-mode-status" id="joyconModeStatus" data-state="loading" role="status" aria-live="polite">Reading saved preference…</p>
-      </section>
-
       <div class="identity-tools">
         <label class="field-label" for="controllerAlias">Controller alias</label>
         <input class="number-input" id="controllerAlias" maxlength="31" placeholder="Optional nickname">
@@ -454,6 +431,37 @@
   </main>
   <form id="macroCaptureSettings" hidden></form>
 
+  <dialog class="adapter-settings-dialog" id="adapterSettingsDialog" aria-labelledby="adapterSettingsTitle" aria-describedby="adapterSettingsDescription">
+    <div class="adapter-settings-heading">
+      <h2 id="adapterSettingsTitle">Adapter settings</h2>
+      <button class="button button-ghost" id="closeAdapterSettingsButton" type="button" autofocus>Close</button>
+    </div>
+    <p class="field-help" id="adapterSettingsDescription">These settings apply to the whole adapter, not the selected profile. Use Apply to save changes; closing keeps unapplied selections.</p>
+      <section class="joycon-mode" aria-labelledby="joyconModeTitle">
+        <p class="eyebrow">Adapter-wide setting</p>
+        <h3 id="joyconModeTitle">Joy-Con 2 default mode</h3>
+        <label class="field-label" for="joyconModeSelect">Default arrangement</label>
+        <select id="joyconModeSelect" class="select" aria-describedby="joyconModeHelp joyconModeStatus" disabled>
+          <option value="paired">Paired · L + R together</option>
+          <option value="individual">Individual · separate players</option>
+        </select>
+        <p class="field-help">Saved on the adapter; changing it applies live and clears temporary joins/splits. Not an artwork preview.</p>
+        <details class="joycon-mode-help">
+          <summary>Controller shortcut &amp; profile banks</summary>
+          <div id="joyconModeHelp">
+            <p><strong>Paired:</strong> L + R share one player and a separate L+R profile bank. Unmatched halves stay separate.</p>
+            <p><strong>Individual:</strong> each half is a sideways player using its own solo bank. Choose the L or R profile owner to edit it.</p>
+            <p><strong>Join / split this pair:</strong> hold <strong>ZL + Minus</strong> on the left and <strong>ZR + Plus</strong> on the right for <strong>2 seconds</strong>. A short pulse confirms success. Release all four buttons before using it again.</p>
+            <p>The shortcut affects only those halves and overrides this default until either disconnects. Other Joy-Cons are unchanged. Each half's complete two-button chord is reserved until both buttons release, even while waiting for the other half. Ambiguous solo selections do not join.</p>
+            <p>All saved banks and unsaved profile drafts are kept. Your chosen owner does not change automatically.</p>
+            <p>Saved preference is not a live pairing report. A pair waits for its L+R bank to be ready; the diagram and live playtest report the actual arrangement.</p>
+          </div>
+        </details>
+        <button class="button button-secondary" id="applyJoyconModeButton" type="button" disabled>Apply default mode</button>
+        <p class="joycon-mode-status" id="joyconModeStatus" data-state="loading" role="status" aria-live="polite">Reading saved preference…</p>
+      </section>
+  </dialog>
+
   <dialog class="copy-dialog" id="copyDialog">
     <form method="dialog">
       <p class="eyebrow">Duplicate profile</p>
diff --git a/src/switch_pico_bridge/web/profile_editor.js b/src/switch_pico_bridge/web/profile_editor.js
index 4fa4d8e..c1331ef 100644
--- a/src/switch_pico_bridge/web/profile_editor.js
+++ b/src/switch_pico_bridge/web/profile_editor.js
@@ -88,6 +88,9 @@ const elements = {
   connection: document.querySelector("#connectionState"),
   connectionText: document.querySelector("#connectionText"),
   identity: document.querySelector("#identitySelect"),
+  adapterSettingsButton: document.querySelector("#adapterSettingsButton"),
+  adapterSettingsDialog: document.querySelector("#adapterSettingsDialog"),
+  closeAdapterSettings: document.querySelector("#closeAdapterSettingsButton"),
   joyconMode: document.querySelector("#joyconModeSelect"),
   applyJoyconMode: document.querySelector("#applyJoyconModeButton"),
   joyconModeStatus: document.querySelector("#joyconModeStatus"),
@@ -2523,6 +2526,19 @@ elements.refresh.addEventListener("click", async () => {
   await loadLibrary(true);
 });
 
+elements.adapterSettingsButton.addEventListener("click", () => {
+  if (!elements.adapterSettingsDialog.open) {
+    renderJoyconMode();
+    elements.adapterSettingsDialog.showModal();
+  }
+});
+elements.closeAdapterSettings.addEventListener("click", () => {
+  elements.adapterSettingsDialog.close();
+});
+elements.adapterSettingsDialog.addEventListener("close", () => {
+  elements.adapterSettingsButton.focus();
+});
+
 elements.joyconMode.addEventListener("change", () => {
   if (elements.joyconMode.disabled) return;
   joyconMode.selected = elements.joyconMode.value;