updated slides

slides/themes/custom-default.css

@@ -0,0 +1,30 @@
+/* custom-default.css */
+/* @theme custom-default */
+
+@import 'default';
+
+.columns {
+  display: grid;
+  grid-template-columns: repeat(2, minmax(0, 1fr));
+  gap: 1rem;
+}
+.columns3 {
+  display: grid;
+  grid-template-columns: repeat(3, minmax(0, 1fr));
+  gap: 1rem;
+} 
+img[alt~="center"] {
+  display: block;
+  margin: 0 auto;
+}
+.fa-twitter { color: aqua; }
+.fa-mastodon { color: purple; }
+.fa-linkedin { color: blue; }
+.fa-window-maximize { color: skyblue; }
+
+svg[id^="mermaid-"] { 
+  max-width: 960px; 
+  max-height: 600px; 
+}
+
+@import 'https://cdnjs.cloudflare.com/ajax/libs/font-awesome/6.3.0/css/all.min.css'