lighter display for checkboxes on headlines frame to fit better with marked/pub icons

css/default.css

@@ -677,6 +677,13 @@ body.ttrss_main #headlines-frame {
   -webkit-transform: translateZ(0);
   -webkit-backface-visibility: hidden;
 }
+body.ttrss_main #headlines-frame .dijitCheckBox:not(.dijitCheckBoxChecked) {
+  background: transparent;
+  opacity: 0.7;
+}
+body.ttrss_main #headlines-frame .dijitCheckBox:not(.dijitCheckBoxChecked)::before {
+  color: #555555;
+}
 body.ttrss_main #headlines-frame div.feed-title {
   border: 0px solid #257aa7;
   border-bottom-width: 1px;

css/tt-rss.less

@@ -796,6 +796,15 @@ body.ttrss_main {
 		-webkit-transform: translateZ(0);
 		-webkit-backface-visibility: hidden;
 
+		.dijitCheckBox:not(.dijitCheckBoxChecked) {
+			background: transparent;
+			opacity : 0.7;
+		}
+
+		.dijitCheckBox:not(.dijitCheckBoxChecked)::before {
+			color : @default-text;
+		}
+
 		div.feed-title {
 			border: 0px solid @color-link;
 			border-bottom-width: 1px;

themes/night.css

@@ -677,6 +677,13 @@ body.ttrss_main #headlines-frame {
   -webkit-transform: translateZ(0);
   -webkit-backface-visibility: hidden;
 }
+body.ttrss_main #headlines-frame .dijitCheckBox:not(.dijitCheckBoxChecked) {
+  background: transparent;
+  opacity: 0.7;
+}
+body.ttrss_main #headlines-frame .dijitCheckBox:not(.dijitCheckBoxChecked)::before {
+  color: #555555;
+}
 body.ttrss_main #headlines-frame div.feed-title {
   border: 0px solid #257aa7;
   border-bottom-width: 1px;