diff --git a/app/static/css/custom.css b/app/static/css/custom.css
index 7fa6712..2cfd07b 100644
--- a/app/static/css/custom.css
+++ b/app/static/css/custom.css
@@ -546,4 +546,60 @@
 
 .app-link:hover {
   color: var(--highlight-color);
+}
+
+/* Validation styles */
+.is-invalid {
+  border-color: #dc3545 !important;
+  padding-right: calc(1.5em + 0.75rem);
+  background-image: url("data:image/svg+xml,%3csvg xmlns='http://www.w3.org/2000/svg' viewBox='0 0 12 12' width='12' height='12' fill='none' stroke='%23dc3545'%3e%3ccircle cx='6' cy='6' r='4.5'/%3e%3cpath stroke-linejoin='round' d='M5.8 3.6h.4L6 6.5z'/%3e%3ccircle cx='6' cy='8.2' r='.6' fill='%23dc3545' stroke='none'/%3e%3c/svg%3e");
+  background-repeat: no-repeat;
+  background-position: right calc(0.375em + 0.1875rem) center;
+  background-size: calc(0.75em + 0.375rem) calc(0.75em + 0.375rem);
+}
+
+.is-valid {
+  border-color: #198754 !important;
+  padding-right: calc(1.5em + 0.75rem);
+  background-image: url("data:image/svg+xml,%3csvg xmlns='http://www.w3.org/2000/svg' viewBox='0 0 8 8'%3e%3cpath fill='%23198754' d='M2.3 6.73L.6 4.53c-.4-1.04.46-1.4 1.1-.8l1.1 1.4 3.4-3.8c.6-.63 1.6-.27 1.2.7l-4 4.6c-.43.5-.8.4-1.1.1z'/%3e%3c/svg%3e");
+  background-repeat: no-repeat;
+  background-position: right calc(0.375em + 0.1875rem) center;
+  background-size: calc(0.75em + 0.375rem) calc(0.75em + 0.375rem);
+}
+
+.invalid-feedback {
+  display: none;
+  width: 100%;
+  margin-top: 0.25rem;
+  font-size: 0.875em;
+  color: #dc3545;
+}
+
+.invalid-feedback.d-block {
+  display: block !important;
+}
+
+.valid-feedback {
+  display: none;
+  width: 100%;
+  margin-top: 0.25rem;
+  font-size: 0.875em;
+  color: #198754;
+}
+
+.valid-feedback.d-block {
+  display: block !important;
+}
+
+/* Fix position for validation messages in table cells */
+td.position-relative {
+  position: relative;
+}
+
+td .feedback {
+  position: absolute;
+  width: 100%;
+  left: 0;
+  top: 100%;
+  z-index: 5;
 }
\ No newline at end of file
diff --git a/app/static/js/validation.js b/app/static/js/validation.js
index 9a60054..07a68a4 100644
--- a/app/static/js/validation.js
+++ b/app/static/js/validation.js
@@ -53,6 +53,13 @@ function validateAppName() {
 // Port Validation
 function validatePort(portField, protocolField) {
   const serverField = document.getElementById('server-id');
+  // Create feedback element if it doesn't exist
+  if (!portField.nextElementSibling || !portField.nextElementSibling.classList.contains('feedback')) {
+    const feedback = document.createElement('div');
+    feedback.className = 'feedback';
+    portField.parentNode.insertBefore(feedback, portField.nextSibling);
+  }
+
   const feedbackElement = portField.nextElementSibling;
   const submitButton = document.querySelector('button[type="submit"]');
 
@@ -65,6 +72,26 @@ function validatePort(portField, protocolField) {
 
   if (!port || !serverId) {
     clearFeedback(feedbackElement);
+    portField.classList.remove('is-invalid');
+    return;
+  }
+
+  // Check for duplicate ports within the form first
+  const allPortFields = document.querySelectorAll('input[name="port_numbers[]"]');
+  const allProtocolFields = document.querySelectorAll('select[name="protocols[]"]');
+  let duplicateFound = false;
+
+  allPortFields.forEach((field, index) => {
+    if (field !== portField &&
+      field.value === port &&
+      allProtocolFields[index].value === protocol) {
+      duplicateFound = true;
+    }
+  });
+
+  if (duplicateFound) {
+    portField.classList.add('is-invalid');
+    showError(feedbackElement, `Duplicate port ${port}/${protocol} in your form`);
     return;
   }
 
@@ -75,22 +102,22 @@ function validatePort(portField, protocolField) {
       .then(response => response.json())
       .then(data => {
         if (!data.valid) {
+          portField.classList.add('is-invalid');
           showError(feedbackElement, data.message);
           if (data.edit_url) {
-            feedbackElement.innerHTML += ` <a href="${data.edit_url}" class="alert-link">Edit the conflicting app?</a>`;
+            feedbackElement.innerHTML += ` <a href="${data.edit_url}" class="alert-link">Edit conflicting app</a>`;
           }
-          portField.classList.add('is-invalid');
-          submitButton.disabled = true;
         } else {
-          clearFeedback(feedbackElement);
           portField.classList.remove('is-invalid');
           portField.classList.add('is-valid');
-          submitButton.disabled = false;
+          showSuccess(feedbackElement, "Port available");
         }
       })
       .catch(error => {
         console.error('Validation error:', error);
         clearFeedback(feedbackElement);
+        portField.classList.remove('is-invalid');
+        portField.classList.remove('is-valid');
       });
   }, 300);
 }
diff --git a/app/templates/dashboard/app_form.html b/app/templates/dashboard/app_form.html
index c00b72e..d5250f6 100644
--- a/app/templates/dashboard/app_form.html
+++ b/app/templates/dashboard/app_form.html
@@ -256,9 +256,10 @@
     const tbody = document.querySelector('#ports-table tbody');
     const newRow = document.createElement('tr');
     newRow.innerHTML = `
-      <td>
+      <td class="position-relative">
         <input type="number" name="port_numbers[]" class="form-control" 
                min="1" max="65535" value="${portNumber}" required>
+        <div class="feedback"></div>
       </td>
       <td>
         <select name="protocols[]" class="form-select">
@@ -279,6 +280,9 @@
       </td>
     `;
     tbody.appendChild(newRow);
+
+    // Set up validation for the new row
+    setTimeout(setupPortValidation, 50);
   }
 
   function removePortRow(button) {