body {
    margin: 0;
    padding: 0;
    font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, Helvetica, Arial, sans-serif;
    background-color: #f8fafc;
}

.barra-navegacao {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 12px 24px;
    background-color: #ffffff;
    border-bottom: 1px solid #e2e8f0;
    box-shadow: 0 1px 3px rgba(0, 0, 0, 0.05);
}

.link-voltar {
    color: #2563eb;
    text-decoration: none;
    font-size: 0.9rem;
    font-weight: 600;
    transition: color 0.2s;
}

.link-voltar:hover {
    color: #1d4ed8;
    text-decoration: underline;
}

.tag-projeto {
    font-size: 0.8rem;
    color: #64748b;
    background: #f1f5f9;
    padding: 4px 10px;
    border-radius: 999px;
    border: 1px solid #e2e8f0;
}

h1 { /* Seleciona todas as tags h1. */
    text-align: center; /* Centraliza horizontalmente o texto. */
    color: #1e293b;
    margin-top: 24px;
} /* Fim das regras do h1. */

#modelo { /* #modelo seleciona o elemento com id="modelo". */
    width: 500px; /* Define largura de 500 pixels. */
    height: 500px; /* Define altura de 500 pixels. */
    background-color: red; /* Define o fundo como vermelho. */
    margin: 0 auto; /* Zera margem vertical e centraliza horizontalmente. */
    border-radius: 12px;
    overflow: hidden;
    box-shadow: 0 10px 25px rgba(0, 0, 0, 0.15);
} /* Fim das regras de #modelo. */