Highlighted code blocks inside the app (#1153)

app/MindWork AI Studio/Tools/CodeHighlighting/Languages/CssCodeRules.cs

@@ -0,0 +1,26 @@
+namespace AIStudio.Tools.CodeHighlighting.Languages;
+
+/// <summary>
+/// How a style sheet in CSS looks to the tokenizer.
+/// </summary>
+/// <remarks>
+/// A style sheet has no statements: it has selectors, such as .card or #main, and blocks of properties
+/// with their values. The tokenizer tells them apart by the braces. At-rules, such as @media, and
+/// !important get the color of keywords, and a function, such as var(), that of functions.
+/// </remarks>
+public static class CssCodeRules
+{
+    public static readonly CodeLanguageRules RULES = new()
+    {
+        IsStyleSheet = true,
+        BlockComments = [new("/*", "*/")],
+        Strings =
+        [
+            new("\"", "\""),
+            new("'", "'"),
+        ],
+
+        WordStartCharacters = "-",
+        WordCharacters = "-",
+    };
+}