Can a CSS class inherit one or more other classes?

Is it possible to make a CSS class that "inherits" from another CSS class (or more than one).

For example, say we had:

.something { display:inline }
.else      { background:red }

What I'd like to do is something like this:

.composite 
{
   .something;
   .else
}

where the ".composite" class would both display inline and have a red background

There are tools like LESS, which allow you to compose CSS at a higher level of abstraction similar to what you describe.

Less calls these "Mixins"

Instead of

/* CSS */

#header {
  -moz-border-radius: 8px;
  -webkit-border-radius: 8px;
  border-radius: 8px;
}

#footer {
  -moz-border-radius: 8px;
  -webkit-border-radius: 8px;
  border-radius: 8px;
}

You could say

/* LESS */

.rounded_corners {
  -moz-border-radius: 8px;
  -webkit-border-radius: 8px;
  border-radius: 8px;
}

#header {
  .rounded_corners;
}

#footer {
  .rounded_corners;
}

You can add multiple classes to a single DOM element, e.g.

<div class="firstClass secondClass thirdclass fourthclass"></div>

Rules given in later classes (or which are more specific) override. So the fourthclass in that example kind of prevails.

Inheritance is not part of the CSS standard.

Yes, but not exactly with that syntax.

.composite,
.something { display:inline }

.composite,
.else      { background:red }

Keep your common attributes together and assign specific (or override) attributes again.

/*  ------------------------------------------------------------------------------ */   
/*  Headings */ 
/*  ------------------------------------------------------------------------------ */   
h1, h2, h3, h4
{
    font-family         : myfind-bold;
    color               : #4C4C4C;
    display:inline-block;
    width:900px;
    text-align:left;
    background-image: linear-gradient(0,   #F4F4F4, #FEFEFE);/* IE6 & IE7 */
}

h1  
{
    font-size           : 300%;
    padding             : 45px 40px 45px 0px;
}

h2
{
    font-size           : 200%;
    padding             : 30px 25px 30px 0px;
}