diff --git a/apps/geolibre-desktop/src/components/layout/DesktopShell.tsx b/apps/geolibre-desktop/src/components/layout/DesktopShell.tsx
index f5b96de388..ae656a8166 100644
--- a/apps/geolibre-desktop/src/components/layout/DesktopShell.tsx
+++ b/apps/geolibre-desktop/src/components/layout/DesktopShell.tsx
@@ -2227,7 +2227,9 @@ export function DesktopShell({
                   // On a phone-width viewport both start collapsed (panels overlay
                   // there), matching the mobile "panels default collapsed" behavior.
                   initialBuiltinExpanded={
-                    replaceLayersPanelId === BROWSER_PANEL_ID && !getIsMobileViewport()
+                    replaceLayersPanelId === BROWSER_PANEL_ID &&
+                    !getIsMobileViewport() &&
+                    !layoutOptions.panelsCollapsed
                   }
                   // The story-map presentation is the only standalone Layers
                   // autoCollapse trigger (the notebook collapses Style, not Layers).
@@ -2267,7 +2269,11 @@ export function DesktopShell({
                       openRasterLayerPanel(createAppAPI(mapControllerRef))
                     }
                     onOpenRasterSubset={setRasterSubsetLayer}
-                    autoCollapse={storymapPresenting || autoCollapsedPanel === "layers"}
+                    autoCollapse={
+                      storymapPresenting ||
+                      layoutOptions.panelsCollapsed ||
+                      autoCollapsedPanel === "layers"
+                    }
                   />
                 )}
               </SectionErrorBoundary>
@@ -2508,7 +2514,10 @@ export function DesktopShell({
                   mapControllerRef={mapControllerRef}
                   onResizeStart={startStylePanelResize}
                   autoCollapse={
-                    notebookOpen || storymapPresenting || autoCollapsedPanel === "style"
+                    notebookOpen ||
+                    storymapPresenting ||
+                    layoutOptions.panelsCollapsed ||
+                    autoCollapsedPanel === "style"
                   }
                 />
               </SectionErrorBoundary>
diff --git a/apps/geolibre-desktop/src/hooks/useLayoutOptions.ts b/apps/geolibre-desktop/src/hooks/useLayoutOptions.ts
index 627fba9cce..6eac49cb23 100644
--- a/apps/geolibre-desktop/src/hooks/useLayoutOptions.ts
+++ b/apps/geolibre-desktop/src/hooks/useLayoutOptions.ts
@@ -14,6 +14,8 @@ export interface LayoutOptions {
    * shared rail — so a map-only embed shows nothing but the map.
    */
   panelsHidden: boolean;
+  /** Start the Layers and Style panels on their rails without hiding them. */
+  panelsCollapsed: boolean;
   showProjectInfo: boolean;
   statusBarVisible: boolean;
   stylePanelVisible: boolean;
@@ -41,6 +43,7 @@ export function layoutOptionsFromLocation(layoutSettings: DesktopLayoutSettings)
       attributePanelVisible: true,
       compact: false,
       panelsHidden: false,
+      panelsCollapsed: false,
       statusBarVisible: true,
       toolbarVisible: true,
       viewer: false,
@@ -67,6 +70,7 @@ export function layoutOptionsFromLocation(layoutSettings: DesktopLayoutSettings)
     mapOnly ||
     HIDDEN_PANEL_VALUES.has(panels) ||
     normalizedParam(params.get("hidePanels")) === "true";
+  const panelsCollapsed = !panelsHidden && panels === "collapsed";
   const toolbarLabels =
     !compact && !ICON_TOOLBAR_VALUES.has(toolbar) ? layoutSettings.toolbarLabels : false;
   const showProjectInfo = compact ? false : layoutSettings.showProjectInfo;
@@ -82,6 +86,7 @@ export function layoutOptionsFromLocation(layoutSettings: DesktopLayoutSettings)
     compact,
     layerPanelVisible,
     panelsHidden,
+    panelsCollapsed,
     showProjectInfo,
     statusBarVisible: !mapOnly,
     stylePanelVisible,
diff --git a/docs/index.md b/docs/index.md
index 71e952b1d2..fdf488933b 100644
--- a/docs/index.md
+++ b/docs/index.md
@@ -152,6 +152,9 @@ https://web.geolibre.app/?url=https://share.geolibre.app/giswqs/3d-tiles.geolibr
 
 Use `toolbar=icons` when you only want icon-only toolbar buttons. `panels=hidden`, `panels=hide`, `panels=off`, and `hidePanels=true` are accepted aliases for hiding panels.
 
+Use `panels=collapsed` to keep the Layers and Style icon rails visible while
+starting both panels collapsed.
+
 For a fully chrome-free, map-only embed, add `&maponly` to hide the toolbar menu, all panels, and the status bar:
 
 ```text
diff --git a/docs/user-guide/embedding.md b/docs/user-guide/embedding.md
index 3c0d39a0d2..52482a0602 100644
--- a/docs/user-guide/embedding.md
+++ b/docs/user-guide/embedding.md
@@ -25,7 +25,7 @@ A chrome-free `maponly` embed shows only the map, as in this shared 3D Tiles pro
 | `url`        | `url=https://share.geolibre.app/you/project.geolibre.json` | Loads a `.geolibre.json` project from a public URL.                                                                                   |
 | `layout`     | `layout=viewer`                                            | `viewer` provides read-only chrome: Layers, View, Controls, basemaps, search/identify, and Help, with authoring UI hidden. `compact` is the icon-only full-app layout; `embed` and `iframe` are aliases. |
 | `toolbar`    | `toolbar=icons`                                            | Icon-only toolbar buttons without the full compact layout. `icon` and `icon-only` are aliases.                                        |
-| `panels`     | `panels=none`                                              | Hides the Layers, Style, and Attribute table panels. `hidden`, `hide`, and `off` are aliases.                                         |
+| `panels`     | `panels=collapsed`                                         | Starts Layers and Style collapsed to their icon rails. Use `none` to hide all panels; `hidden`, `hide`, and `off` are aliases.         |
 | `hidePanels` | `hidePanels=true`                                          | Alternative way to hide those panels.                                                                                                 |
 | `maponly`    | `maponly`                                                  | Hides all chrome (toolbar, panels, and status bar), leaving only the map. The bare flag or `true`, `1`, `yes`, `on` enable it.        |
 | `welcome`    | `welcome=0`                                                | Hides the first-launch welcome wizard. Accepts `0`, `false`, `off`, or `no`. A `url=` deep link already suppresses it automatically.  |
diff --git a/tests/layout-options.test.ts b/tests/layout-options.test.ts
index 8f6f9d0e02..c7f49a6759 100644
--- a/tests/layout-options.test.ts
+++ b/tests/layout-options.test.ts
@@ -29,6 +29,7 @@ describe("layoutOptionsFromLocation", () => {
     assert.equal(options.stylePanelVisible, true);
     assert.equal(options.attributePanelVisible, true);
     assert.equal(options.panelsHidden, false);
+    assert.equal(options.panelsCollapsed, false);
   });
 
   it("hides every chrome element when maponly is set as a bare flag", () => {
@@ -88,6 +89,17 @@ describe("layoutOptionsFromLocation", () => {
     assert.equal(options.panelsHidden, true);
   });
 
+  it("starts side panels collapsed without hiding their rails", () => {
+    withSearch("?panels=collapsed");
+    const options = layoutOptionsFromLocation(DEFAULT_DESKTOP_LAYOUT_SETTINGS);
+    assert.equal(options.toolbarVisible, true);
+    assert.equal(options.layerPanelVisible, true);
+    assert.equal(options.stylePanelVisible, true);
+    assert.equal(options.attributePanelVisible, true);
+    assert.equal(options.panelsHidden, false);
+    assert.equal(options.panelsCollapsed, true);
+  });
+
   it("provides read-only viewer chrome between the full app and maponly", () => {
     withSearch("?layout=viewer");
     const options = layoutOptionsFromLocation(DEFAULT_DESKTOP_LAYOUT_SETTINGS);