diff --git a/static/app.js b/static/app.js
index 58a714b..bffebaf 100644
--- a/static/app.js
+++ b/static/app.js
@@ -1,6 +1,11 @@
 function initApp() {
   console.log('sub-aligator app.js initialized');
 
+  // Ensure every modal starts closed, even if the browser restored a cached state.
+  document.querySelectorAll('.modal-overlay').forEach(function (modal) {
+    modal.style.display = 'none';
+  });
+
   // Open allocation modal
   document.querySelectorAll('.allocate-btn').forEach(function (btn) {
     btn.addEventListener('click', function () {
@@ -46,6 +51,16 @@ function initApp() {
       event.stopPropagation();
     });
   });
+
+  // Hide the modal right before its form is submitted.
+  document.querySelectorAll('.modal form').forEach(function (form) {
+    form.addEventListener('submit', function () {
+      const overlay = form.closest('.modal-overlay');
+      if (overlay) {
+        overlay.style.display = 'none';
+      }
+    });
+  });
 }
 
 async function openAllocateModal(btn) {