diff --git a/web/src/styles.css b/web/src/styles.css
index 065d7e1..afe24c3 100644
--- a/web/src/styles.css
+++ b/web/src/styles.css
@@ -1215,6 +1215,9 @@ textarea {
 /* ---------- forms ---------- */
 
 .spawn-form {
+  width: 100%;
+  max-width: 60ch;
+  margin: 0 auto;
   padding: var(--sp-3);
   overflow: auto;
   display: flex;