使用react bootstrap在台式机中一行显示4张卡，在平板电脑版本中一行显示2张卡

npm install react-bootstrap

import React from 'react';
import { Container, Row, Col, Card } from 'react-bootstrap';

class MyComponent extends React.Component {
  render() {
    return (
      <Container>
        <Row>
          <Col md={3} sm={6}>
            <Card>Card 1</Card>
          </Col>
          <Col md={3} sm={6}>
            <Card>Card 2</Card>
          </Col>
          <Col md={3} sm={6}>
            <Card>Card 3</Card>
          </Col>
          <Col md={3} sm={6}>
            <Card>Card 4</Card>
          </Col>
        </Row>
      </Container>
    );
  }
}