diff --git a/src/claude_code_transcripts/__init__.py b/src/claude_code_transcripts/__init__.py
index e4854a3b..d8a323d9 100644
--- a/src/claude_code_transcripts/__init__.py
+++ b/src/claude_code_transcripts/__init__.py
@@ -701,7 +701,14 @@ def format_json(obj):
 def render_markdown_text(text):
     if not text:
         return ""
-    return markdown.markdown(text, extensions=["fenced_code", "tables"])
+    # Render literal HTML in message text as visible text rather than live markup: an unclosed
+    # <style>/<script> in a prompt would otherwise swallow the rest of the page. Deregistering the
+    # HTML handlers (rather than escaping the input first) keeps fenced code blocks intact, since
+    # fenced_code stashes their content in a preprocessor that runs before html_block.
+    md = markdown.Markdown(extensions=["fenced_code", "tables"])
+    md.preprocessors.deregister("html_block")
+    md.inlinePatterns.deregister("html")
+    return md.convert(text)
 
 
 def is_json_like(text):
diff --git a/tests/test_generate_html.py b/tests/test_generate_html.py
index 25c28224..bcbbff44 100644
--- a/tests/test_generate_html.py
+++ b/tests/test_generate_html.py
@@ -131,6 +131,20 @@ def test_render_markdown_text_empty(self):
         assert render_markdown_text("") == ""
         assert render_markdown_text(None) == ""
 
+    def test_render_markdown_text_escapes_literal_html(self):
+        """Literal HTML in message text renders as visible text, not live markup."""
+        result = render_markdown_text("Leave the <head> and the <style> block alone.")
+        assert "&lt;head&gt;" in result
+        assert "&lt;style&gt;" in result
+        assert "<head>" not in result
+        assert "<style>" not in result
+
+    def test_render_markdown_text_keeps_fenced_html(self):
+        """A fenced code block containing HTML is preserved as escaped code, not dropped."""
+        result = render_markdown_text("text\n\n```html\n<div>x</div>\n```")
+        assert "<pre>" in result
+        assert "&lt;div&gt;x&lt;/div&gt;" in result
+
     def test_format_json(self, snapshot_html):
         """Test JSON formatting."""
         result = format_json({"key": "value", "number": 42, "nested": {"a": 1}})
