Problemas com import

Failed to compile

./src/components/ListaDeNotas.jsx Module not found: Can't resolve './CardNota' in 'C:\Users\Magna\Desktop\reac-estudo\ceep\src\components'

This error occurred during the build time and cannot be dismissed.

trecho do código :

import React, { Component } from 'react';
import "./estilo.css"
class CardNota extends Component {
    render() {
        return (
        <section className = "card-nota">
            <header>
                <h3>Título</h3>
            </header>
            <p>Escreva sua Nota</p>
        </section>);
    }
}

export default CardNota;

e o css:

.card-nota{
    color: rebeccapurple;
}

Fiz como o instrutor mas deu esse erro..