fix some dark mode logic glitches & random clean up

layouts/partials/scripts/fathom.html

@@ -1,13 +0,0 @@
-<script>
-  (function(j, a, r, v, i, s){
-    a[v]=a[v]||function(){
-      (a[v].q=a[v].q||[]).push(arguments)
-    };
-    i=j.createElement('script'),
-    s=j.getElementsByTagName('script')[0];
-    i.async=1; i.src=r; i.id='fathom-script';
-    s.parentNode.insertBefore(i,s)
-  })(document, window, 'https://s.jarv.is/tracker.js', 'fathom');
-  fathom('set', 'siteId', 'DYCXU');
-  fathom('trackPageview');
-</script>