diff --git a/css/index.css b/css/index.css
index 1db3b97a..a2993a3f 100644
--- a/css/index.css
+++ b/css/index.css
@@ -5196,3 +5196,133 @@ body {
 .subject-sidebar-item:hover .delete-subject-btn {
   opacity: 1;
 }
+
+/* Toast Notifications (Issue #1210) */
+.toast-container {
+  position: fixed;
+  top: 24px;
+  right: 24px;
+  display: flex;
+  flex-direction: column;
+  gap: 12px;
+  z-index: 9999;
+  pointer-events: none;
+}
+
+.toast-notification {
+  pointer-events: auto;
+  display: flex;
+  align-items: center;
+  gap: 12px;
+  padding: 12px 16px;
+  border-radius: var(--border-radius-md);
+  background: var(--color-background-primary);
+  border: 1px solid var(--color-border-secondary);
+  box-shadow: var(--shadow-md);
+  backdrop-filter: blur(12px);
+  min-width: 300px;
+  max-width: 450px;
+  animation: toastSlideIn 0.35s cubic-bezier(0.16, 1, 0.3, 1) forwards;
+}
+
+.toast-icon {
+  font-size: 18px;
+  display: flex;
+  align-items: center;
+  justify-content: center;
+}
+
+.toast-message {
+  font-size: 13px;
+  font-weight: 500;
+  color: var(--color-text-primary);
+  line-height: 1.4;
+}
+
+.toast-close {
+  background: none;
+  border: none;
+  font-size: 18px;
+  cursor: pointer;
+  color: var(--color-text-secondary);
+  opacity: 0.6;
+  margin-left: auto;
+  padding: 0;
+  display: flex;
+  align-items: center;
+  justify-content: center;
+  transition: opacity 0.2s;
+}
+
+.toast-close:hover {
+  opacity: 1;
+}
+
+/* Toast Variants */
+.toast-success {
+  background: var(--color-background-success);
+  color: var(--color-text-success);
+  border-color: var(--color-border-success);
+}
+.toast-success .toast-message,
+.toast-success .toast-close {
+  color: var(--color-text-success);
+}
+
+.toast-error {
+  background: var(--color-background-danger);
+  color: var(--color-text-danger);
+  border-color: var(--color-border-danger);
+}
+.toast-error .toast-message,
+.toast-error .toast-close {
+  color: var(--color-text-danger);
+}
+
+.toast-warning {
+  background: var(--color-background-warning);
+  color: var(--color-text-warning);
+  border-color: rgba(133, 79, 11, 0.2);
+}
+.toast-warning .toast-message,
+.toast-warning .toast-close {
+  color: var(--color-text-warning);
+}
+
+.toast-info {
+  background: var(--color-background-info);
+  color: var(--color-text-info);
+  border-color: var(--color-border-info);
+}
+.toast-info .toast-message,
+.toast-info .toast-close {
+  color: var(--color-text-info);
+}
+
+.toast-notification.toast-hiding {
+  animation: toastSlideOut 0.3s cubic-bezier(0.7, 0, 0.84, 0) forwards;
+}
+
+/* Keyframes */
+@keyframes toastSlideIn {
+  from {
+    transform: translateX(120%);
+    opacity: 0;
+  }
+  to {
+    transform: translateX(0);
+    opacity: 1;
+  }
+}
+
+@keyframes toastSlideOut {
+  from {
+    transform: translateX(0);
+    opacity: 1;
+  }
+  to {
+    transform: translateX(120%);
+    opacity: 0;
+  }
+}
+
diff --git a/package-lock.json b/package-lock.json
index 56528823..e9685a4e 100644
--- a/package-lock.json
+++ b/package-lock.json
@@ -16,7 +16,7 @@
         "sqlite3": "^6.0.1"
       },
       "engines": {
-        "node": "20.x"
+        "node": ">=20.x"
       }
     },
     "node_modules/@google/genai": {