title: Set border for QSpinBox when focused
body: <p>For already existed Qt project I'd like set border for focused widgets through qss-fle. But I faced out with some unexpected result. When I change border of <code>QSpinBox</code> (and <code>QDoubleSpinBox</code>) border will change as I expect but up-button and down-button change too and look ugly.</p>
  
  <p><a href="https://i.stack.imgur.com/pHSaO.png" rel="noreferrer"><img src="https://i.stack.imgur.com/pHSaO.png" alt="enter image description here"></a></p>
  
  <p>Here is my style definition (full example available <a href="https://gitlab.com/Gluttton/SOS/tree/master/35162425" rel="noreferrer">here</a>):</p>
  
  <pre><code>QSpinBox:focus
  {
      border-width: 2px;
      border-style: solid;
      border-color: green;
  }
  </code></pre>
  
  <p>My question is: how to change appearance of border and simultaneously preserve appearance of up-button and down-button. Solution what I am looking for shouldn't be cross platform or cross version.</p>
  
  <p>My environment:<br>
  - KUbuntu 15.10 (amd64);<br>
  - Qt 5.4 (x64).</p>
  
  <p><strong>Update</strong>:</p>
  
  <p>Here is one more example with another style:</p>
  
  <pre><code>QSpinBox
  {
      border-width: 2px;
      border-style: solid;
      border-color : red;
  }
  
  QSpinBox:hover
  {
      border-width: 2px;
      border-style: solid;
      border-color: blue;
  }
  </code></pre>
  
  <p>The widget looks like this:</p>
  
  <p><a href="https://i.stack.imgur.com/kX2Kl.png" rel="noreferrer"><img src="https://i.stack.imgur.com/kX2Kl.png" alt="enter image description here"></a></p>