diff --git a/packages/dashboard/app/styles.css b/packages/dashboard/app/styles.css
index 9fd6fc02c..68bd46ffc 100644
--- a/packages/dashboard/app/styles.css
+++ b/packages/dashboard/app/styles.css
@@ -4431,6 +4431,30 @@ html .column.drag-over * {
   height: 100%;
 }
 
+/* Textarea-based file editor */
+.file-editor-textarea {
+  width: 100%;
+  min-width: 100%;
+  height: 100%;
+  background: var(--bg);
+  color: var(--text);
+  font-family: "SF Mono", Monaco, Consolas, monospace;
+  font-size: 14px;
+  line-height: 1.5;
+  padding: 16px;
+  border: none;
+  outline: none;
+  resize: none;
+  white-space: pre;
+  overflow-wrap: normal;
+  tab-size: 2;
+}
+
+.file-editor-textarea::selection {
+  background: var(--todo);
+  color: var(--bg);
+}
+
 /* File States */
 .file-error {
   padding: 12px 16px;