Update to reveal.js 4.6.1
Change-Id: I566737c50b93dd8c094ad3c3fa59865260b3b4ba
diff --git a/inst/reveal.js-4.6.1/css/theme/source/black-contrast.scss b/inst/reveal.js-4.6.1/css/theme/source/black-contrast.scss
new file mode 100644
index 0000000..9e1a2ca
--- /dev/null
+++ b/inst/reveal.js-4.6.1/css/theme/source/black-contrast.scss
@@ -0,0 +1,49 @@
+/**
+ * Black compact & high contrast reveal.js theme, with headers not in capitals.
+ *
+ * By Peter Kehl. Based on black.(s)css by Hakim El Hattab, http://hakim.se
+ *
+ * - Keep the source similar to black.css - for easy comparison.
+ * - $mainFontSize controls code blocks, too (although under some ratio).
+ */
+
+
+// Default mixins and settings -----------------
+@import "../template/mixins";
+@import "../template/settings";
+// ---------------------------------------------
+
+
+// Include theme-specific fonts
+@import url(./fonts/source-sans-pro/source-sans-pro.css);
+
+
+// Override theme settings (see ../template/settings.scss)
+$backgroundColor: #000000;
+
+$mainColor: #fff;
+$headingColor: #fff;
+
+$mainFontSize: 42px;
+$mainFont: 'Source Sans Pro', Helvetica, sans-serif;
+$headingFont: 'Source Sans Pro', Helvetica, sans-serif;
+$headingTextShadow: none;
+$headingLetterSpacing: normal;
+$headingTextTransform: uppercase;
+$headingFontWeight: 600;
+$linkColor: #42affa;
+$linkColorHover: lighten( $linkColor, 15% );
+$selectionBackgroundColor: lighten( $linkColor, 25% );
+
+$heading1Size: 2.5em;
+$heading2Size: 1.6em;
+$heading3Size: 1.3em;
+$heading4Size: 1.0em;
+
+// Change text colors against light slide backgrounds
+@include light-bg-text-color(#000);
+
+
+// Theme template ------------------------------
+@import "../template/theme";
+// ---------------------------------------------