Can we just plop some CSS right smack in the middle of our JavaScript code?!

MyComponent.js

import React from "react";

body {
  font-family: Helvetica, sans-serif;
}
.header-text {
  font-weight: bold;
  font-size: 2em;
}

class MyComponent extends React.Component {
  render() {
    return (
      <div>
        <h1 className="header-text">Hello there!</h1>
      </div>
    );
  }
}

export default MyComponent;

No you cannot