How to always keep the sidebar visible in wordpress for PC resolutions

I'm making a portal with WordPress and the virtue theme, and I would like it for large resolutions (more than 992px wide) the sidebar on the right (sidebar) should remain fixed, and when they are smaller it should appear at the end ( right now this behavior does it but when scrolling the bar disappears)

The style in question in the sidebar is div.sidebar

If I redefine the style in the additional css of the theme in the following way:

@media (min-width: 992px) {
  div.sidebar{ 
    height:100%; 
    position:fixed; 
    width:250px;
  }
}

Does what I want, but of course, I lose the original style of the div.sidebar (font styles, width, alignment, etc).

Is it possible to add the attributes height: 100% and position: fixed to the original style, obviously keeping the rest of the attributes?

Thanks