Keep button green also when in focus

static/css/vipsobsapp.css

@@ -23,7 +23,7 @@ a.nav-link{
 	border-color: #3d8052;
 }
 
-.btn-primary, .btn-primary:hover {
+.btn-primary, .btn-primary:hover, .btn-primary:focus, .btn-primary.focus {
 	background-color: #3d8052;
 	border-color: #3d8052;
 }