/**src/App.css**/

​

 .bg{

background-color: #03f4fc;

​

}

/**src/App.js**/

​

function App() {

​

  return (

    <>

 <Container>

      <Row  className="bg">

        <Col className="border">1 of 2</Col>

        <Col className="border">2 of 2</Col>

      </Row>

      <Row className="bg">

        <Col className="border">1 of 3</Col>

        <Col className="border">2 of 3</Col>

        <Col className="border">3 of 3</Col>

      </Row>

    </Container>

    </>

  );

}

​