I've written a new indenter for CSS, which fixes issues with mulitline
statements following a colon, and comments:

body {
    color: #333;
    font: 15px "Helvetica Neue",
        Helvetica,
        Arial,
        "Nimbus Sans L",
        sans-serif;
    font-weight: 300;
    line-height: 1.625;
    a { /* It also handles SCSS */
        font: 15px "Helvetica Neue",
            Helvetica,
            Arial,
            "Nimbus Sans L",
            sans-serif;
        /* Some comment */
    }
    /* Some comment at the end of a block */
}

I wondered whether this functionality could be integrated into Emacs.
https://github.com/sabof/es-css-mode
https://github.com/sabof/es-lib (it takes some functions from it)

Evgeni