knockout component with custom element styling

HTML

<script src="http://knockoutjs.com/downloads/knockout-3.4.0.js"></script>
<h1 data-bind="text: message">

</h1>
<x-a>

</x-a>

CSS

message-editor {
  font-size: 19px;
}

JavaScript

ko.components.register('x-a', {
    viewModel: function(params) {
        this.text = ko.observable("");
    },
    template: '<div><span>inner of a before templ</span>'+
    '<!-- ko template: { nodes: $componentTemplateNodes, data: $data } --><!-- /ko -->'+
    '<span>inner of a after templ</span></div> '
});

ko.applyBindings({message: "Hello"});