CartoCSS for a neon sign effect as used in http://cdb.io/15ekzYE

neontext.css

@occurrences0inner: #5EF2F4;
@occurrences0outer: #272BB3;

@occurrences1inner: #FAFEFE;
@occurrences1outer: #07A40B;

@occurrences2inner: #FFE721;
@occurrences2outer: #95521E;

@occurrences3inner: #EFFC40;
@occurrences3outer: #D71208;


/*
 * Common text properties
 */
#sign_application_filings::outer,
#sign_application_filings::inner {
  text-name: [text_on_sign];
  text-face-name: "DejaVu Sans Book";
  
  /* Wrapping */
  text-wrap-width: 20;
  text-ratio: 0;
  
  /* Tilt and placement */
  text-orientation: [rotation] / 3;
  text-placement-type: simple;
  text-allow-overlap: true;
  
  /* Spacing */
  text-line-spacing: -2;
  text-character-spacing: 1;
}

/*
 * Text sizes
 */
#sign_application_filings::outer,
#sign_application_filings::inner {
  [zoom <= 10] {
    text-size: 4;
  }
  
  [zoom <= 12] {
    text-size: 10;
  }
  
  text-size: 15;
  
  [zoom >= 15] {
    text-size: 20;
  }
}

#sign_application_filings::outer {
  text-halo-radius: 5;
  [zoom <= 13] {
    text-halo-radius: 3;
  }
  [zoom <= 11] {
    text-halo-radius: 1;
  }

  text-opacity: 0.6;

  /*
   * Halo and fill colors based on 
   * number of occurrences
   */
  text-halo-fill: @occurrences0outer;
  text-fill: @occurrences0outer;
  [text_occurrences > 2] {
    text-halo-fill: @occurrences1outer;
    text-fill: @occurrences1outer;
  }
  [text_occurrences > 4] {
    text-halo-fill: @occurrences2outer;
    text-fill: @occurrences2outer;
  }
  [text_occurrences > 6] {
    text-halo-fill: @occurrences3outer;
    text-fill: @occurrences3outer;
  }

}

#sign_application_filings::inner {
  /*
   * Fill colors based on number of 
   * occurrences
   */
  text-fill: @occurrences0inner;
  [text_occurrences > 2] {
    text-fill: @occurrences1inner;
  }
  [text_occurrences > 4] {
    text-fill: @occurrences2inner;
  }
  [text_occurrences > 6] {
    text-fill: @occurrences3inner;
  }
}