diff --git a/apps/api/app/admin/files.rb b/apps/api/app/admin/files.rb
index d9e8720..41dc6b4 100644
--- a/apps/api/app/admin/files.rb
+++ b/apps/api/app/admin/files.rb
@@ -13,11 +13,16 @@ ActiveAdmin.register_page "Files" do
       entries = []
     end
 
+    # Picker mode: hide admin header/menu/footer
+    if picker_mode
+      text_node '<style>#header,#tabs,.footer,#title_bar,#utility_nav{display:none!important}#active_admin_content{margin:0;padding:0}#wrapper{margin:0}body{min-height:auto}</style>'.html_safe
+    end
+
     div class: "file-manager" do
       h2 do
         text_node "File Manager"
         if picker_mode
-          span " (Select a file)", style: "font-size:14px; color:#888; font-weight:normal;"
+          span " — select a file or folder", style: "font-size:14px; color:#888; font-weight:normal;"
         end
       end
 
@@ -117,7 +122,7 @@ ActiveAdmin.register_page "Files" do
                   text_node " "
                   abs_path = "/softwares/#{entry[:path]}"
                   a "Select", href: "#", class: "fm-btn fm-btn-select",
-                    onclick: "window.opener.postMessage({type:'file-picked',field:'#{j picker_field}',path:'#{j abs_path}'},'*');window.close();return false;"
+                    onclick: "window.parent.postMessage({type:'file-picked',field:'#{j picker_field}',path:'#{j abs_path}'},'*');return false;"
                 end
 
                 # Hidden rename form
diff --git a/apps/api/app/assets/javascripts/active_admin.js b/apps/api/app/assets/javascripts/active_admin.js
index 320ebc5..bbe762d 100644
--- a/apps/api/app/assets/javascripts/active_admin.js
+++ b/apps/api/app/assets/javascripts/active_admin.js
@@ -14,17 +14,54 @@
         btn.className = 'fm-browse-btn';
         btn.addEventListener('click', function(e) {
           e.preventDefault();
-          window.open(
-            '/admin/files?picker=1&field=' + encodeURIComponent(input.id),
-            'file_picker',
-            'width=960,height=640,scrollbars=yes,resizable=yes'
-          );
+          openFilePicker(input.id);
         });
         input.parentNode.insertBefore(btn, input.nextSibling);
       });
     });
   }
 
+  function openFilePicker(fieldId) {
+    // Backdrop
+    var overlay = document.createElement('div');
+    overlay.className = 'fm-modal-overlay';
+    overlay.addEventListener('click', function(e) {
+      if (e.target === overlay) closeFilePicker();
+    });
+
+    // Modal container
+    var modal = document.createElement('div');
+    modal.className = 'fm-modal';
+
+    // Close button
+    var closeBtn = document.createElement('button');
+    closeBtn.className = 'fm-modal-close';
+    closeBtn.innerHTML = '&times;';
+    closeBtn.addEventListener('click', closeFilePicker);
+    modal.appendChild(closeBtn);
+
+    // Iframe
+    var iframe = document.createElement('iframe');
+    iframe.src = '/admin/files?picker=1&field=' + encodeURIComponent(fieldId);
+    iframe.className = 'fm-modal-iframe';
+    modal.appendChild(iframe);
+
+    overlay.appendChild(modal);
+    document.body.appendChild(overlay);
+    document.body.style.overflow = 'hidden';
+
+    window._fmOverlay = overlay;
+  }
+
+  function closeFilePicker() {
+    if (window._fmOverlay) {
+      window._fmOverlay.remove();
+      window._fmOverlay = null;
+      document.body.style.overflow = '';
+    }
+  }
+
+  // Listen for file selection from iframe
   window.addEventListener('message', function(event) {
     if (event.data && event.data.type === 'file-picked') {
       var input = document.getElementById(event.data.field);
@@ -32,6 +69,7 @@
         input.value = event.data.path;
         input.dispatchEvent(new Event('change', { bubbles: true }));
       }
+      closeFilePicker();
     }
   });
 
diff --git a/apps/api/app/assets/stylesheets/active_admin.scss b/apps/api/app/assets/stylesheets/active_admin.scss
index 711e0f7..e16c841 100644
--- a/apps/api/app/assets/stylesheets/active_admin.scss
+++ b/apps/api/app/assets/stylesheets/active_admin.scss
@@ -29,6 +29,22 @@
 
 // Browse button in release forms
 .fm-browse-btn {
-  display: inline-block; margin-left: 8px; padding: 4px 10px; background: #6c757d; color: #fff; border-radius: 3px; font-size: 11px; text-decoration: none; vertical-align: middle;
-  &:hover { background: #5a6268; color: #fff; }
+  display: inline-block; margin-left: 8px; padding: 4px 10px; background: #6c757d; color: #fff !important; border-radius: 3px; font-size: 11px; text-decoration: none !important; vertical-align: middle;
+  &:hover { background: #5a6268; color: #fff !important; }
+  &:visited { color: #fff !important; }
+}
+
+// Inline file picker modal
+.fm-modal-overlay {
+  position: fixed; inset: 0; z-index: 9999; background: rgba(0,0,0,0.6); display: flex; align-items: center; justify-content: center;
+}
+.fm-modal {
+  position: relative; width: 90vw; max-width: 1000px; height: 80vh; background: #fff; border-radius: 8px; box-shadow: 0 20px 60px rgba(0,0,0,0.3); overflow: hidden;
+}
+.fm-modal-close {
+  position: absolute; top: 8px; right: 12px; z-index: 10; background: none; border: none; font-size: 28px; color: #666; cursor: pointer; line-height: 1;
+  &:hover { color: #000; }
+}
+.fm-modal-iframe {
+  width: 100%; height: 100%; border: none;
 }