add visually-hidden css class to pointhi style

searx/static/themes/oscar/css/pointhi.css

@@ -211,6 +211,17 @@ input[type=checkbox]:not(:checked) + .label_hide_if_checked + .label_hide_if_not
   font-weight: bold;
   background-color: #EEE;
 }
+.visually-hidden {
+  position: absolute !important;
+  height: 1px;
+  width: 1px;
+  overflow: hidden;
+  clip: rect(1px 1px 1px 1px);
+  /* IE6, IE7 */
+  clip: rect(1px, 1px, 1px, 1px);
+  white-space: nowrap;
+  /* added line */
+}
 #advanced-search-container {
   display: none;
   text-align: center;

searx/static/themes/oscar/less/pointhi/search.less

@@ -31,3 +31,13 @@
         background-color: #EEE;
     }
 }
+
+.visually-hidden {
+    position: absolute !important;
+    height: 1px;
+    width: 1px;
+    overflow: hidden;
+    clip: rect(1px 1px 1px 1px); /* IE6, IE7 */
+    clip: rect(1px, 1px, 1px, 1px);
+    white-space: nowrap; /* added line */
+}