[colinramsay]

Here's the discussion where they changed from "var-" to "--":

http://lists.w3.org/Archives/Public/www-style/2014Mar/0261.h...

And later on the justification for not using $ or @:

http://lists.w3.org/Archives/Public/www-style/2014Mar/0400.h...

There's also the issue that this needs to be backwards compatible with parsers that don't support the syntax, and apparently because the variables cascade that makes it harder still. I agree it's ugly though.

[evolve2k]

From the second link in parent:

"> As far as I understand, the main reason of why Tab's original idea of using `$` has eventually been dropped was some uncertainty about its possible extensibility for being used in property _names_ besides property _values_.

The reason it got dropped is that some people (including Tab) do believe we should reserve $ for mixins and other preprocessor-like operations which may potentially be added to the language at some point. e.g. futuristic things like:

    @define apply-2d-transform(initial-scale, initial-rotation, ...) {
        ...
        my-transform-scaling: $initial-scale;
        my-transform-rotation: $initial-rotation;
        ...
        transform:
            scale(get(my-transform-scaling))
            rotate(get(my-transform-rotation))
            translate(get(my-transform-translation));
        will-change[]:
            transform;
    }

    .some-element {
        $apply-2d-transform(...);
        transition[]: transform 0.5s ease-in-out;
    }

    .some-element:hover {
        my-transform-scale: 1.1;
    }

but this syntax was just made for this example, final milage may look completely different and/or offer different features)"

[tyleregeto]

I don't get that argument. Sass manages to avoid $ conflicts while using it for both variables and mixins. Its nice clean, consistent syntax. I don't see why we need different syntax for the two. Eg:

  $myColor: #fff;

  a {
    color: $myColor;
  }

  @mixin border-radius($radius) {
    -webkit-border-radius: $radius;
    -moz-border-radius: $radius;
    -ms-border-radius: $radius;
    border-radius: $radius;
  }

  .box { @include border-radius(10px); }

[IgorPartola]

This is just stupid. Here are some sigils they could have easily used without much issue: #, *, +. They could have also used something like [var-name] or <var-name>.

I am convinced that at this point CSS is a clusterfuck that should be killed with fire.

[aquanext]

And one thing we should kill it with is GSS. (http://gridstylesheets.org)

Watch the video!

[luikore]

Variable is a BIG change in CSS. If a browser doesn't support variable, then new stylesheets are already broken in that browser. It makes little difference to make the syntax compatible.

Once an easy-to-use syntax is published, toolchains that parse CSS will update as fast as they can! But "--"? Everybody will stick to the old standard and never want to upgrade.

[riffraff]

where is the discussion for using `var()` ?

The rationale for the "--" sigil matches what I'd expected, but I don't understand: why not just `name: --value` ?