Collapse empty phone detail pane

main.go

@@ -1078,6 +1078,17 @@ func (u *ui) shouldShowDesktopWorkingHeader() bool {
 	return u.mode == "desktop" && !u.shouldShowLifecycleSetup() && !u.isVaultLocked()
 }
 
+func (u *ui) shouldUseCompactPhoneDetailPane() bool {
+	if u.mode != "phone" {
+		return false
+	}
+	if u.isVaultLocked() || u.editingEntry {
+		return false
+	}
+	_, ok := u.selectedEntry()
+	return !ok
+}
+
 func (u *ui) chooseExistingFileAction(target *widget.Editor) error {
 	path, err := pickExistingFile()
 	if err != nil {
@@ -1384,7 +1395,12 @@ func (u *ui) layout(gtx layout.Context) layout.Dimensions {
 							layout.Rigid(layout.Spacer{Height: unit.Dp(6)}.Layout),
 							layout.Rigid(u.phoneSlider),
 							layout.Rigid(layout.Spacer{Height: unit.Dp(6)}.Layout),
-							layout.Flexed(1, u.detailPanel),
+							func() layout.FlexChild {
+								if u.shouldUseCompactPhoneDetailPane() {
+									return layout.Rigid(u.detailPanel)
+								}
+								return layout.Flexed(1, u.detailPanel)
+							}(),
 						)
 					}
 					return layout.Flex{Axis: layout.Horizontal}.Layout(gtx,