How to exclude particular class name in CSS selector?

Question

I'm trying to apply background-color when a user mouse hover the element whose class name is "reMode_hover".

But I do not want to change color if the element also has "reMode_selected"

Note: I can only use CSS not javascript because I'm working within some sort of limited environment.

To clarify, my goal is to color the first element on hover but not the second element.

HTML

<a href="" title="Design" class="reMode_design  reMode_hover">
    <span>Design</span>
</a>

<a href="" title="Design" 
 class="reMode_design  reMode_hover reMode_selected">
    <span>Design</span>
</a>

I tried below hoping the first definition would work but it is not. What am I doing wrong?

CSS

/* do not apply background-color so leave this empty */
.reMode_selected .reMode_hover:hover 
{
}

.reMode_hover:hover 
{
   background-color: #f0ac00;
}

Answer 1

One way is to use the multiple class selector (no space as that is the descendant selector):

.reMode_hover:not(.reMode_selected):hover 
{
   background-color: #f0ac00;
}

<a href="" title="Design" class="reMode_design  reMode_hover">
    <span>Design</span>
</a>

<a href="" title="Design" 
 class="reMode_design  reMode_hover reMode_selected">
    <span>Design</span>
</a>