diff --git a/loop/webui/src/sketch-app-shell.css b/loop/webui/src/sketch-app-shell.css
new file mode 100644
index 0000000..57c96df
--- /dev/null
+++ b/loop/webui/src/sketch-app-shell.css
@@ -0,0 +1,22 @@
+html,
+body {
+  height: 100%;
+  overflow-y: auto;
+}
+
+body {
+  font-family:
+    system-ui,
+    -apple-system,
+    BlinkMacSystemFont,
+    "Segoe UI",
+    Roboto,
+    sans-serif;
+  margin: 0;
+  padding: 0;
+  color: #333;
+  line-height: 1.4;
+  overflow-x: hidden; /* Prevent horizontal scrolling */
+  display: flex;
+  flex-direction: column;
+}