style #portalContainer for settings

Author: adlk

src/styles/layout.scss

@@ -172,4 +172,12 @@ body.win32 .window-draggable {
   width: auto;
   z-index: 999999999;
   pointer-events: none;
+}
+
+#portalContainer {
+  position: absolute;
+  top: 0;
+  left: 0;
+  width: 100%;
+  height: 100%;
 }