bookmarklet-reload-css.js

(function(){
  function reloadCSS() {
    var now = Date.now();
    var stylesheets = document.querySelectorAll('link[rel=stylesheet][href]');

    window.console.info('Reload! ' + now);
    Array.prototype.forEach.call(stylesheets, function (element) {
      var newUrl = element.href.replace(/(&|%5C?)forceReload=\d+/, '');
      element.href = newUrl + (newUrl.match(/\?/) ? '&' : '?') + 'forceReload=' + now;
    });
  }
  window.addEventListener('keyup', function (event) {
    if (event.code === 'KeyR' && event.shiftKey === true) {
      reloadCSS();
    }
  });
  reloadCSS();
}());