My browser does not match my CSS (but jQuery does)

Question

Consider these classes:

.bio-target-measure {
  opacity: 1;
}
.bio-target-measure:not(.lowerThird-25.lowerThird-active):not(.lowerThird-50.lowerThird-active):not(.lowerThird-100.lowerThird-active):not(.middleThird-25.middleThird-active):not(.middleThird-50.middleThird-active):not(.middleThird-100.middleThird-active):not(.upperThird-25.upperThird-active):not(.upperThird-50.upperThird-active):not(.upperThird-100.upperThird-active):not(.bud-25.bud-active):not(.bud-50.bud-active):not(.bud-100.bud-active) {
  opacity: 0 !important;
}

<div class="mark bio-target-measure upperThird-100" title="Muestra
        Plaga: Oidio
        ID: [4]
        Tercios: [&quot;upperThird&quot;]" style="width:100.0%;height:100%;color:white;background-color:#6a6200;">Test</div>

And these jQuery call:

var measures = $('.bio-target-measure');
measures.length; // evaluates to 1.
measures.is('.bio-target-measure:not(.lowerThird-25.lowerThird-active):not(.lowerThird-50.lowerThird-active):not(.lowerThird-100.lowerThird-active):not(.middleThird-25.middleThird-active):not(.middleThird-50.middleThird-active):not(.middleThird-100.middleThird-active):not(.upperThird-25.upperThird-active):not(.upperThird-50.upperThird-active):not(.upperThird-100.upperThird-active):not(.bud-25.bud-active):not(.bud-50.bud-active):not(.bud-100.bud-active)');
// evaluates to true.

var emptyMeasures = $('.bio-target-measure:not(.lowerThird-25.lowerThird-active):not(.lowerThird-50.lowerThird-active):not(.lowerThird-100.lowerThird-active):not(.middleThird-25.middleThird-active):not(.middleThird-50.middleThird-active):not(.middleThird-100.middleThird-active):not(.upperThird-25.upperThird-active):not(.upperThird-50.upperThird-active):not(.upperThird-100.upperThird-active):not(.bud-25.bud-active):not(.bud-50.bud-active):not(.bud-100.bud-active)');
emptyMeasures.length; // evaluates to 1.

But the opacity for such element, which satisfies the selector for opacity: 0 !important; (as it was seen using jQuery), is 1. My Google Chrome (47.0.2526.106, Ubuntu 15.04, 64bits) browser uses only the first rule (the only is to clarify: rule with opacity 0 is not present-but-overriden: is totally absent in the match).

Question: is the :not rule (as I used it) a valid CSS selector? I know it works in jQuery, but I ask about CSS.

Answer 1

Following from @Harry's comment, you cannot have combined selectors in your :not(). (Evidence provided by @TJCrowder: :not, simple selector, sequence of selectors)

In a case like this, you will need to rework your logic:

.bio-target-measure.lowerThird-25:not(.lowerThird-active),
.bio-target-measure.lowerThird-50:not(.lowerThird-active),
...

This can be made a lot easier using LESS or a similar higher-level version of CSS:

.bio-target-measure {
    &.lowerThird-25, &.lowerThird-50, &.lowerThird-100 {
        &:not(.lowerThird-active) {
            opacity: 0 !important;
        }
    }
    /* define similar blocks for middleThird and upperThird */
}

The above will compile into the complicated selector suggested in the first code block, while being much easier to read.