Estrutura básica de css

style.css

body {
    font-family: 'Montserrat', sans-serif;
    background-color: #f2f2f2;
}

header {
    background-color: #009933; /* Verde Brasil */
    color: white;
    text-align: center;
    padding: 20px;
}

#hero {
    background-image: url('campo-de-futebol.jpg');
    background-size: cover;
    height: 500px;
    display: flex;
    align-items: center;
    justify-content: center;
    color: white;
}