dark mode in docs

website/js/docs/loader.js

@@ -1,3 +1,61 @@
 $( document ).ready( function () {
     $( '#nav' ).load( '/docs/nav.html' );
+    $( '#top' ).load( '/docs/top.html' );
+    setTimeout( setTheme, 300 );
 } );
+
+
+let theme = sessionStorage.getItem( 'theme' ) || getPreferredTheme();
+
+// set theme on page load
+function setTheme () {
+    if ( theme == 'dark' ) {
+        document.getElementById( 'darkToggle' ).innerHTML = '☼';
+        $( '.content' ).css( 'background-color', 'rgb(46, 46, 46)' );
+        $( '.top-container' ).css( 'background-color', 'rgb(100, 100, 100)' );
+        $( '.content' ).css( 'color', 'white' );
+        $( '.nav-subitem' ).css( 'background-color', 'rgb(18, 18, 99)' );
+        $( '.navitem' ).css( 'background-color', 'rgb(12, 12, 60)' );
+        $( '.nav-container' ).css( 'background-color', 'rgb(0, 0, 100)' );
+    }
+}
+
+// retreive preferred theme from browser preferences if not in session storage
+function getPreferredTheme () {
+    if ( window.matchMedia( '(prefers-colorscheme: dark)' ).matches ) {
+        setPreferredTheme( 'dark' );
+        return 'dark';
+    } else {
+        setPreferredTheme( 'light' );
+        return 'light';
+    };
+}
+
+// set theme in session storage
+function setPreferredTheme ( userTheme ) {
+    sessionStorage.setItem( 'theme', userTheme );
+    theme = userTheme;
+}
+
+// change theme
+function toggleDarkMode () {
+    if ( theme == 'light' ) {
+        $( '.content' ).animate( { 'background-color': 'rgb(46, 46, 46)' } );
+        $( '.top-container' ).animate( { 'background-color': 'rgb(100, 100, 100)' } );
+        $( '.nav-subitem' ).animate( { 'background-color': 'rgb(18, 18, 99)' } );
+        $( '.navitem' ).animate( { 'background-color': 'rgb(12, 12, 60)' } );
+        $( '.nav-container' ).animate( { 'background-color': 'rgb(0, 0, 100)' } );
+        $( '.content' ).animate( { 'color': 'white' } );
+        document.getElementById( 'darkToggle' ).innerHTML = '☼';
+        setPreferredTheme( 'dark' );
+    } else {
+        $( '.content' ).animate( { 'background-color': 'white' } );
+        $( '.content' ).animate( { 'color': 'black' } );
+        $( '.nav-subitem' ).animate( { 'background-color': 'rgb(27, 27, 165)' } );
+        $( '.navitem' ).animate( { 'background-color': 'rgb(22, 22, 117)' } );
+        $( '.nav-container' ).animate( { 'background-color': 'blue' } );
+        $( '.top-container' ).animate( { 'background-color': 'rgb(223, 223, 223)' } );
+        document.getElementById( 'darkToggle' ).innerHTML = '☽';
+        setPreferredTheme( 'light' );
+    }
+}