anchor.diff:        //minZoom: 8,
         maxZoom: 14
         }).setView([38.8951, -77.0364], 8);
  +      map.legendControl.addLegend(document.getElementById('legend').innerHTML);
         map.on('popupopen', function(event) {
           twttr.widgets.load();
         });
  
positive.code:     style.
        body { margin:0; padding:0; }
        #map { position:absolute; top:0; bottom:0; width:100%; }
      script.
        window.twttr = (function(d, s, id) {
        var js, fjs = d.getElementsByTagName(s)[0],
  
negative.code:     meta(charset='utf-8')
      title Single marker
      meta(name='viewport', content='initial-scale=1,maximum-scale=1,user-scalable=no')
      link(src='//mapbox.com/base/latest/base.css', rel='stylesheet')
      script(src='https://api.mapbox.com/mapbox.js/v2.2.1/mapbox.js')
      link(href='https://api.mapbox.com/mapbox.js/v2.2.1/mapbox.css', rel='stylesheet')
      script(src='https://api.mapbox.com/mapbox.js/plugins/leaflet-markercluster/v0.4.0/leaflet.markercluster.js')
  