Fix background of popup menus that was transparent (black)

In the properties view, the context menu on the title line would be black
making its content unreadable. Same in the filter line of the "Set Custom icon"
window on the outline's context menu.

manuskript/ui/views/outlineBasics.py

@@ -203,7 +203,7 @@ class outlineBasics(QAbstractItemView):
             txt = QLineEdit()
             txt.textChanged.connect(self.filterLstIcons)
             txt.setPlaceholderText("Filter icons")
-            txt.setStyleSheet("background: transparent; border: none;")
+            txt.setStyleSheet("QLineEdit { background: transparent; border: none; }")
             act = QWidgetAction(self.menuCustomIcons)
             act.setDefaultWidget(txt)
             self.menuCustomIcons.addAction(act)

manuskript/ui/views/propertiesView_ui.py

@@ -20,7 +20,7 @@ class Ui_propertiesView(object):
         font.setBold(True)
         font.setWeight(75)
         self.txtTitle.setFont(font)
-        self.txtTitle.setStyleSheet("background:transparent;")
+        self.txtTitle.setStyleSheet("QLineEdit { background:transparent; }")
         self.txtTitle.setFrame(False)
         self.txtTitle.setObjectName("txtTitle")
         self.verticalLayout.addWidget(self.txtTitle)

manuskript/ui/views/propertiesView_ui.ui

@@ -35,7 +35,7 @@
       </font>
      </property>
      <property name="styleSheet">
-      <string notr="true">background:transparent;</string>
+      <string notr="true">QLineEdit { background:transparent; }</string>
      </property>
      <property name="frame">
       <bool>false</bool>