Widgets/style sheets: border-bottom property not working

I am using this version of Qt Creator:
Qt Creator 4.0.1
Based on Qt 5.6.1 (MSVC 2013, 32 bit)
Built on Jun 6 2016 17:10:42
From revision 6863acfe91
Copyright 2008-2016 The Qt Company Ltd. All rights reserved.

Description: When trying setting border-bottom property, e.g. "border-bottom: 1px solid #ff0000", it is not showing up.
Expected result: Working border-bottom CSS property, since it is clearly stated that this property is supported (http://doc.qt.io/qt-4.8/stylesheet-reference.html#list-of-properties).

Steps to reproduce:
1. Select any widget.
2. By changing its stylesheet, set "border-bottom: 1px solid #ff0000".
3. Click "Apply".
4. No result will be shown.

Possible workaround:
border: 1px solid #ff0000;
border-top: none;
border-left: none;
border-right: none;