switch from gulp to vite to build, add types for reveal.js config

css/theme/serif.scss

@@ -0,0 +1,38 @@
+/**
+ * A simple theme for reveal.js presentations, similar
+ * to the default theme. The accent color is brown.
+ *
+ * This theme is Copyright (C) 2012-2013 Owen Versteeg, http://owenversteeg.com - it is MIT licensed.
+ */
+
+// Default mixins and settings -----------------
+@use "sass:color";
+@import "../template/mixins";
+@import "../template/settings";
+// ---------------------------------------------
+
+// Override theme settings (see ../template/settings.scss)
+$mainFont: "Palatino Linotype", "Book Antiqua", Palatino, FreeSerif, serif;
+$mainColor: #000;
+$headingFont: "Palatino Linotype", "Book Antiqua", Palatino, FreeSerif, serif;
+$headingColor: #383d3d;
+$headingTextShadow: none;
+$headingTextTransform: none;
+$backgroundColor: #f0f1eb;
+$linkColor: #51483d;
+$linkColorHover: color.scale($linkColor, $lightness: 20%);
+$selectionBackgroundColor: #26351c;
+
+$overlayElementBgColor: 0, 0, 0;
+$overlayElementFgColor: 240, 240, 240;
+
+.reveal a {
+  line-height: 1.3em;
+}
+
+// Change text colors against dark slide backgrounds
+@include dark-bg-text-color(#fff);
+
+// Theme template ------------------------------
+@import "./template/theme";
+// ---------------------------------------------