fix disabled button state

src/ui/pages/batch-save-urls.css

@@ -115,10 +115,15 @@ button {
     cursor: pointer;
 }
 
-button:not([disabled]):hover {
+button:not(:disabled):hover {
     background-color: #ededed;
 }
 
+button:disabled {
+    opacity: .25;
+    cursor: default;
+}
+
 body>header button,
 body>footer button {
     margin-top: 5px;
@@ -403,7 +408,7 @@ html.side-panel,
         background-color: #ccc;
     }
 
-    button:hover {
+    button:not(:disabled):hover {
         color: #2A2A2E;
     }