Enhance template parser to handle C++ comments and refactor preprocessing logic

- Updated parser to correctly interpret C++ `//` and `/* ... */` comments within template code.
- Split preprocessing implementation into separate files for better organization.
- Added regression test for comment parsing in templates.
- Adjusted CSS styles for improved layout and readability in documentation.

site/test/index.uce

@@ -33,6 +33,7 @@ RENDER(Request& context)
 			<div class="grid-heading">Data Types &amp; Parsing</div>
 			<? render_card("dtree.uce", "DTree", "Dynamic hierarchical data tree"); ?>
 			<? render_card("json.uce", "JSON", "Parse and encode JSON data"); ?>
+			<? render_card("preprocessor-comments.uce", "Preprocessor Comments", "Regression coverage for comment parsing in templates"); ?>
 			<? render_card("string.uce", "String", "String operations"); ?>
 			<? render_card("str_replace.uce", "String Replace", "Search and replace in strings"); ?>
 			<? render_card("utf8.uce", "UTF-8", "Unicode string handling"); ?>

site/test/preprocessor-comments.uce

@@ -0,0 +1,39 @@
+RENDER(Request& context)
+{
+	// Regression: this comment contains <> and an apostrophe that shouldn't start a literal block: <>
+	String outer_status = "outer parser ok";
+
+	<>
+		<link rel="stylesheet" href='style.css?v=<?= time() ?>'></link>
+		<h1>
+			<a href="index.uce">UCE Test</a>:
+			Preprocessor Comments
+		</h1>
+
+		<p>This page exists to prove the template parser ignores quotes and template markers that appear inside C++ comments.</p>
+
+		<?
+		// Regression: this comment's apostrophe must not swallow the later ?> marker.
+		String inline_status = "inline comment ok";
+		?>
+
+		<?
+		/*
+			Regression: block comments may contain "quotes", apostrophe's, and <> markers
+			without confusing the parser or the generated .cpp output.
+		*/
+		String block_status = "block comment ok";
+		?>
+
+		<ul>
+			<li>Outer code scan: <code><?= outer_status ?></code></li>
+			<li>Markup code island with // comment: <code><?= inline_status ?></code></li>
+			<li>Markup code island with /* */ comment: <code><?= block_status ?></code></li>
+		</ul>
+
+		<details>
+			<summary>Request Parameters</summary>
+			<pre><?= var_dump(context.params) ?></pre>
+		</details>
+	</>
+}

site/test/style.css

@@ -2,12 +2,12 @@
    Color palette: deep blue gradient · warm gold accents · frosted glass surfaces */
 
 :root {
-	--bg: #0b1d4e;
-	--bg-grad: linear-gradient(168deg, #0f2462 0%, #0b1d4e 40%, #091840 100%);
+	--bg: #113399;
+	--bg-grad: linear-gradient(168deg, #1a3daa 0%, #113399 40%, #0d2880 100%);
 	--bg-surface: rgba(255, 255, 255, 0.05);
 	--bg-surface-hover: rgba(255, 255, 255, 0.09);
-	--bg-inset: rgba(0, 0, 0, 0.3);
-	--bg-code: rgba(0, 0, 0, 0.32);
+	--bg-inset: rgba(0, 0, 0, 0.28);
+	--bg-code: rgba(0, 0, 0, 0.3);
 	--text: #dfe5f2;
 	--text-dim: rgba(200, 210, 235, 0.6);
 	--text-muted: rgba(200, 210, 235, 0.35);