diff --git a/internal/web/static/app.css b/internal/web/static/app.css
index b158596..7b996e9 100644
--- a/internal/web/static/app.css
+++ b/internal/web/static/app.css
@@ -311,6 +311,9 @@ html[data-wrap] .float { overflow-x: hidden; }
 .codeline { display: block; }
 /* #167 rev: gutter number spans must stack one per visual row (wrap on) */
 .code .gutter .gutline { display: block; }
+/* #194: codeline blocks are adjacent (no '\n' text between them), so an
+   empty block (blank source line) needs its own line box to stay one row */
+.codeline:empty::before { content: "\200B"; }
 /* syntax highlight tokens (#1) */
 .tok-kw { color: #c792ea; }
 .tok-str { color: #a5e075; }
diff --git a/internal/web/static/paste-lines.js b/internal/web/static/paste-lines.js
index 048e3b5..58b907b 100644
--- a/internal/web/static/paste-lines.js
+++ b/internal/web/static/paste-lines.js
@@ -13,7 +13,13 @@
   };
 
   // Wrap each logical line (split on newline; spans never contain newlines
-  // because HighlightCode highlights per line) in a .codeline block.
+  // because HighlightCode highlights per line) in a .codeline block. The
+  // blocks must be adjacent with NO newline text between them (#194):
+  // .codeline is display:block, and under pre-wrap each interleaved '\n'
+  // text node renders as an extra phantom row in the code column that
+  // renumber() does not count, drifting the gutter off alignment on
+  // wrapped lines. Blank lines become empty blocks; .codeline:empty keeps
+  // them one row tall (see app.css).
   function splitLines() {
     var html = body.innerHTML;
     var parts = html.split('\n');
@@ -21,7 +27,7 @@
     for (var i = 0; i < parts.length; i++) {
       out.push('<span class="codeline">' + parts[i] + '</span>');
     }
-    body.innerHTML = out.join('\n');
+    body.innerHTML = out.join('');
   }
 
   function renumber() {