Make X icon parent position: relative; to prevent it from floating on its own.

src/components/post_status_form/post_status_form.vue

@@ -53,6 +53,10 @@
      .attachments {
          padding: 0.5em;
 
+         .attachment {
+           position: relative;
+         }
+
          i {
             position: absolute;
             margin: 10px;