Strange default size in leaflet map

I have taken a working Leaflet map, but when I added a JQuery Mobile header and back button the formatting went crazy.

Initially loading the page all the contents is loaded in the upper-left-hand corner, but when the page is resized the smallest bit on a desktop, or rotated on a mobile, everything is fine.

This is what it looks like when opened:

and what it looks like after rotating (and what it should be):

Here is the code for the page

<!DOCTYPE html>
<html>
<head>
<title>Toronto CAD Activity Map</title>
<meta charset="utf-8" />
<meta name="viewport" content="width=device-width, initial-scale=1.0">
<link rel="stylesheet" href="../css/leaflet.css" />
 <meta name="viewport" content="width=device-width, initial-scale=1">
<link rel="stylesheet" href="../css/tfscad.mobile.css" />
<link rel="stylesheet" href="../css/jquery.mobile-1.4.5.min.css">
<link rel="stylesheet" href="../css/font-awesome.min.css">
<script src="../js/jquery-1.11.1.min.js"></script>
<script src="../js/jquery.mobile-1.4.5.min.js"></script>
<script src="../js/iframeResizer.contentWindow.js"></script>

<!--[if lte IE 8]><link rel="stylesheet" href="../dist/leaflet.ie.css" /><![endif]-->
<style>
#mapPage {
  height: calc(100% - 42px);
}

#map {
  height: 100%;
}

#map-content{
  height: 100%;
  padding: 0px; 
  margin:0px;
  z-index: -1;
}
#curLoc{
  position: absolute;
  bottom: 0;
  left: 10px;
}
</style>
</head>


<body>
<body>
    <div data-role="page" id="mapPage" data-theme="a"> 
        <div data-role="header" data-position="fixed" data-theme="a">
            <a id="backButton" href="#" data-rel="back" 
                data-transition="slide" data-direction="reverse">Back</a>
            <h1>Toronto CAD Map</h1>
        </div> 

        <div id="map-content" data-role="content">
            <div id="map"></div>
        </div>
        <a id="curLoc" data-role="button" data-icon="location" data-iconpos="notext"></a>

    </div> 
<script src="../js/jquery-1.11.1.min.js"></script> 
<script src="../js/leaflet.js"></script> 

<script type="text/javascript">
 window.onload = function() {
getGeoJson();
getTPSJson();
};
 
    var map = L.map('map').setView([43.7178,-79.3762], 11);
        L.tileLayer('https://{s}.tile.openstreetmap.org/{z}/{x}/{y}.png', {
            attribution: 'Map data &copy; 2011 OpenStreetMap contributors, Imagery &copy; 2012 CloudMade',
               }).addTo(map);



function getGeoJson(){
 
  // load GeoJSON from an external file
  $.getJSON("../appdata/geo.json",function(data){

      L.geoJson(data  ,{
    pointToLayer: function(feature,latlng){
       
       var TFS = new L.icon({
       iconUrl: '../images/tfs_logo.png',
      iconSize:     [22, 22],
      popupAnchor:  [0, -22]
      });

     var TPS = new L.icon({
       iconUrl: '../images/tps_logo.png',
      iconSize:     [22, 22],
      popupAnchor:  [0, -22]
      });

     var ESC = new L.icon({
       iconUrl: '../images/tps_logo.png',
      iconSize:     [22, 22],
      popupAnchor:  [0, -22]
      });         
 if(feature.properties.icon == 'TFS'){
    var marker = L.marker(latlng,{icon: TFS});
  marker.bindPopup('<strong>' + feature.properties.event_type + '</strong><br/>' + feature.properties.OPEN_DT);
  return marker; 
    
  }else if(feature.properties.icon == 'TPS'){
    var marker = L.marker(latlng,{icon: TPS});
  marker.bindPopup('<strong>' + feature.properties.event_type + '</strong><br/>' + feature.properties.OPEN_DT);
  return marker; 

  }else if(feature.properties.icon == 'ESC'){    
    var marker = L.marker(latlng,{icon: ESC});
  marker.bindPopup('<strong>' + feature.properties.event_type + '</strong><br/>' + feature.properties.OPEN_DT);
  return marker; 
  }
      }
  }  ).addTo(map);
  }); 
 
 
}

function getTPSJson(){
 
var myStyle = {
  "color": "#ff7800",
  "weight": 5,
  "opacity": 0,
  "offset": 1.5
};

  // load GeoJSON from an external file
  $.getJSON("../appdata/TPSDiv.json",function(myLines){

 L.geoJson(myLines, {
style: myStyle
}).addTo(map);
})
}


 setInterval(function()
{ 
 
getGeoJson();

}, 10000);//time in milliseconds  

    function onClick(e) {
        //console.log(this.options.win_url);
        window.open(this.options.win_url);
    }
 
    
</script>
</body>

Strange default size in leaflet map

2 Answers