include a script

wrap script tags in head elements in any blogpost, e.g.

<head>
  <script>
    function dhtmlLoadScript(url) {
       var e = document.createElement("script");
       e.src = url;
       e.type="text/javascript";
       document.getElementsByTagName("head")[0].appendChild(e);
    }
    dhtmlLoadScript("https://www.mysite.com/mydata.js");
  </script>
</head>

include css for only current page

same as above, but wrap in <style></style>

<div id="special">
  i'm styled using using #special in the head of this md file
</div>

custom font

<link href="https://fonts.googleapis.com/css?family=Zilla+Slab:300,400" rel="stylesheet">
<div style="font-family:'Zilla Slab'">