Issue 2408 - Improved accessibility of checkboxes in options page

skin/options.css

Index: skin/options.css
===================================================================
--- a/skin/options.css
+++ b/skin/options.css
@@ -92,6 +92,25 @@
   box-sizing: border-box;
 }
 
+button[role="checkbox"]
+{
+  vertical-align: top;
+  width: 18px;
+  height: 18px;
+  margin-top: 0px;
+  -moz-margin-end: 20px;
+  -webkit-margin-end: 20px;
+  padding: 0px 0px 0px 0px;
+  border: none;
+  background-color: transparent;
+  background-position: -51px 0px;
+}
+
+button[role="checkbox"][aria-checked="true"]
+{
+  background-position: -68px 0px;
+}
+
 .option-name
 {
   display: flex;
@@ -403,34 +422,6 @@
   background-color: #A1A1A1;
 }
 
-.table input[type="checkbox"]
-{
-  margin-top: 0px;
-  -moz-margin-end: 20px;
-  -webkit-margin-end: 20px;
-  padding: 0px 0px 0px 0px;
-  visibility: hidden;
-}
-
-.table input[type="checkbox"]::before
-{
-  content: "";
-  background-position: -51px 0px;
-  height: 18px;
-  width: 18px;
-  visibility: visible;
-}
-
-.table input[type="checkbox"]:checked::before
-{
-  content: "";
-  background-position: -68px 0px;
-  height: 18px;
-  padding: 0px;
-  width: 18px;
-  visibility: visible;
-}
-
 .table button.delete
 {
   background-color: transparent;
@@ -477,8 +468,11 @@
   padding-bottom: 10px;
 }
 
-.icon, .table input[type="checkbox"]::before, .table button.delete,
-#content-help a::before, #dialog-close::before,
+.icon,
+button[role="checkbox"],
+.table button.delete,
+#content-help a::before,
+#dialog-close::before,
 #custom-filters-add button::after,
 #dialog-body button::before
 {