JSFiddle - React, Tailwind, and code Playground

HTML

<div id="app">
  <form data-bind="with: form">
    <label>
      First:
      <input type="text" data-bind="value: firstName">
    </label>
    <label>
      Last:
      <input type="text" data-bind="value: lastName">
    </label>
  </form>
  <div>
    You are: <span data-bind="text: name"></span>
  </div>
</div>

JavaScript

function ViewModel() {
  this.form = {
    firstName: ko.observable("Joe"),
    lastName: ko.observable("Bloggs")
  };
  this.name = ko.computed(function () {
  	return this.form.firstName() + ' ' + this.form.lastName();
  }, this);
};

ko.applyBindings(new ViewModel(), document.getElementById('app'));