No borders around buttons in dark themes

[brazh]

Hi!

I have a problem with dark themes in Lubuntu 17.04. When I choose widget with dark colors (for example Elementary Dark), than in some applications I don't see borders around buttons, checkboxes and so on. Look at screenshots, where you can see problems in "LightDM GTK+ Greeter settings" window:

here I chose Lubuntu-default widget and everything is normal:
https://preview.ibb.co/gjkfCF/theme_light.png (https://ibb.co/mWy0CF)

and here I chose Elementary-Dark widget and there are no borders:
https://preview.ibb.co/mZaQev/theme_dark.png (https://ibb.co/k10rKv)

The same thing happens even when I choose standard widget Lubuntu-dark-panel. Can you help me to make Lubuntu draw borders in dark themes?

[Frogs Hair]

From what I find elementary dark was intended to work properly with GTK 3.4(2011 era) and that may explain why it won't display properly. Did you install this theme from an outside source ?