kjs_css.js

/**
 * CSS addon for Kongregate Asynchronous JavaScript Loader
 *
 * Adds support to KJS for loading CSS files.
 *
 * You can find KJS at:
 * https://gist.github.com/388e70bccd3fdb8a6617
 *
 * Usage:
 *
 *     kjs.loadCss('styles.css');  // loads stylesheet
 *     kjs.load('ui.js', [ 'styles.css' ]);  // loads javascript after
 *                                           // stylesheet is fully loaded
 */

KJS.prototype.loadCSS = function(file, depends, satisfies) {
  var kjs = this,
      satisfy = function(s) {
        return function(body) {
          kjs.embedCSS(body);
          for (var i = s.length - 1; i >= 0; i--) { kjs.sat(s[i]); }
        };
      }((satisfies || []).concat(file.split('?')[0]));
  
  this.get(this._path + file, function(body) {
    depends && depends.length ?
      kjs.run(function() { satisfy(body); }, depends) :
      satisfy(body);
  });
}

KJS.prototype.embedCSS = function(body) {
  var s = document.createElement('style');
  document.getElementsByTagName('head')[0].appendChild(s);
  s.innerHTML = body;
};

kjs_css_test.js

function testEmbedCSS() {
  var kjs = new KJS(),
      styles = 'p { color: #111 }';
  kjs.embedCSS(styles);

  assertEquals("Expected style tag to have been appended to document head with provided body",
    styles, document.getElementsByTagName('head')[0].lastChild.innerHTML);
}

function testLoadCSSWithSatisfies() {
  var kjs = new KJS();
  kjs.get = function(url, fn) { fn("contents of " + url); };
  kjs.embedCSS = function() {};
  
  var has_been_run = false;
  kjs.run(function() { has_been_run = true; }, [ '/a.js' ]);
  kjs.loadCSS('/bundle.js', [], [ '/a.js' ]);
  assertTrue("Expected callback with virtual dependencies to have been satisfied", has_been_run);
}

Nice.
From EFWS:

stylesheets followed by an inline script block any subsequent resources from downloading