Is there a CSS not equals selector?

You could also approach this by targeting an attribute like this:

input:not([type=checkbox]){ width:100%; }

In this case all inputs that are not 'checkbox' type will have a width of 100%.

You can also do that by 'reverting' the changes on the reset class only in CSS.

INPUT { 
    padding: 0px;
}
INPUT.reset {
    padding: 4px;
}

CSS3 has :not(), but it's not implemented in all browsers yet. It is implemented in the IE9 Platform Preview, however.

input:not(.reset) { }

http://www.w3.org/TR/css3-selectors/#negation

In the meantime, you'll have to stick to the old-fashioned methods.

In CSS3, you can use the :not() filter, but not all browsers fully support CSS3 yet, so be sure you know what you're doing which is now supported by all major browsers (and has been for quite some time; this is an old answer...).

Example:

<input type="text" value="will be matched" />
<input type="text" value="will not be matched" class="avoidme" />
<input type="text" value="will be matched" />

and the CSS

input:not(.avoidme) { background-color: green; }

---

Note: this workaround shouldn't be necessary any more; I'm leaving it here for context.

If you don't want to use CSS3, you can set the style on all elements, and then reset it with a class.

input { background-color: green; }
input.avoidme { background-color: white; }