app.js

import './style/app.css!'; //note, had to add the !
import React from 'react';
import ReactDOM from 'react-dom';
import * as KendoReactButtons from '@telerik/kendo-react-buttons';
import '@telerik/kendo-react-buttons/dist/npm/css/main.css!'; //note, had to add the !
import { square, diag } from './js/math.js';

console.log(square(11)); // 121
console.log(diag(4, 3)); // 5

class ButtonContainer extends React.Component {
    constructor(props) {
        super(props);
        this.state = {
            disabled: false
        };
    }
    onClick = () => {
        this.setState({ disabled: !this.state.disabled });
    }
    render() {
        return (
            <div>
                <KendoReactButtons.Button onClick={this.onClick}>Button 1</KendoReactButtons.Button>
                <KendoReactButtons.Button disabled={this.state.disabled}>Button 2</KendoReactButtons.Button>
            </div>
        );
    }
}

ReactDOM.render(
    <div>
        <p>Button</p>
        <KendoReactButtons.Button>Button test</KendoReactButtons.Button>
        <p>Disabled Button</p>
        <KendoReactButtons.Button disabled>Button</KendoReactButtons.Button>
        <p>Primary Button</p>
        <KendoReactButtons.Button primary>Primary Button</KendoReactButtons.Button>
        <p>Button with icon</p>
        <KendoReactButtons.Button icon="refresh">Refresh</KendoReactButtons.Button>
        <p>Button with icon (imageUrl)</p>
        <KendoReactButtons.Button imageUrl="http://demos.telerik.com/kendo-ui/content/shared/icons/sports/snowboarding.png">Snowboarding</KendoReactButtons.Button>
        <p>Button with a custom icon (iconClass) [FontAwesome icon]</p>
        <KendoReactButtons.Button iconClass="fa fa-key fa-fw">FontAwesome icon</KendoReactButtons.Button>
        <p>Toggleable Button</p>
        <KendoReactButtons.Button togglable>Togglable button</KendoReactButtons.Button>
        <p>onClick event handler</p>
        <ButtonContainer />
    </div>,
    document.getElementById('app')
);