:root {
    --primary-color: #0073e6;
    --dark-blue: #0d253f;
    --light-gray: #f4f4f4;
    --text-color: #333;
    --light-text: #ffffff;
    --container-width: 960px;
}

body {
    font-family: 'Roboto', sans-serif;
    margin: 0;
    padding: 0;
    line-height: 1.6;
    background-color: var(--light-gray);
    color: var(--text-color);
}

main p {
    text-align: justify;
}

.container {
    max-width: var(--container-width);
    margin: 0 auto;
    padding: 0 20px;
}

header {
    background-color: var(--dark-blue);
    color: var(--light-text);
    padding: 40px 0;
    text-align: center;
}

.header-content {
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 40px;
}

@media (min-width: 768px) {
    .header-content {
        flex-direction: row;
        text-align: left;
    }
}

.cover-image {
    flex-shrink: 0;
}

.cover-image img {
    max-width: 300px;
    height: auto;
    border-radius: 8px;
    box-shadow: 0 10px 20px rgba(0, 0, 0, 0.2);
}

.header-text h1 {
    font-size: 2.8em;
    margin: 0 0 10px 0;
    font-weight: 700;
}

.header-text h2 {
    font-size: 1.5em;
    margin: 0 0 20px 0;
    font-weight: 300;
    color: #a0c8e8;
}

.header-text .subtitle {
    font-size: 1.2em;
    margin-bottom: 30px;
    font-weight: 400;
}

.form-container {
    background-color: rgba(255, 255, 255, 0.1);
    padding: 25px;
    border-radius: 8px;
    border: 1px solid rgba(255, 255, 255, 0.2);
}

.form-container h3 {
    margin-top: 0;
    font-size: 1.4em;
}

.form-container p {
    margin: 0 0 15px 0;
}

.form-container form {
    display: flex;
    flex-direction: column;
    gap: 10px;
}

@media (min-width: 500px) {
    .form-container form {
        flex-direction: row;
    }
}

.form-container input[type="email"] {
    flex-grow: 1;
    padding: 12px;
    border: 1px solid #ccc;
    border-radius: 4px;
    font-size: 1em;
}

.form-container button {
    padding: 12px 20px;
    background-color: var(--primary-color);
    color: white;
    border: none;
    border-radius: 4px;
    font-size: 1em;
    cursor: pointer;
    transition: background-color 0.3s;
}

.form-container button:hover {
    background-color: #005bb5;
}

.release-note {
    font-size: 0.9em;
    margin-top: 15px !important;
    opacity: 0.8;
}

main section {
    padding: 60px 0;
    border-bottom: 1px solid #ddd;
}

main section:last-child {
    border-bottom: none;
}

h2 {
    text-align: center;
    font-size: 2.2em;
    margin-bottom: 40px;
}

#highlights .highlight-cards {
    display: grid;
    grid-template-columns: 1fr;
    gap: 30px;
}

@media (min-width: 600px) {
    #highlights .highlight-cards {
        grid-template-columns: repeat(2, 1fr);
    }
}
@media (min-width: 900px) {
    #highlights .highlight-cards {
        grid-template-columns: repeat(3, 1fr);
    }
}

#highlights .card {
    background-color: white;
    padding: 25px;
    border-radius: 8px;
    box-shadow: 0 4px 6px rgba(0,0,0,0.1);
}

#highlights .card h3 {
    margin-top: 0;
    color: var(--primary-color);
}

#table-of-contents .summary-grid {
    display: grid;
    grid-template-columns: 1fr;
    gap: 30px;
}

/* AQUI A MUDANÇA PARA 2 COLUNAS */
@media (min-width: 768px) {
    #table-of-contents .summary-grid {
        grid-template-columns: repeat(2, 1fr);
    }
}

#table-of-contents h4 {
    margin-top: 0;
    color: var(--dark-blue);
    border-bottom: 2px solid var(--primary-color);
    padding-bottom: 10px;
}

#table-of-contents ul {
    list-style: none;
    padding: 0;
    margin: 0;
}

#table-of-contents li {
    margin-bottom: 8px;
    font-size: 0.95em;
}

#author .author-content p {
    text-indent: 1.5em;
}

/* Estilos para a nova seção "Para Quem é Este Livro?" */
#for-who .for-who-cards {
    display: grid;
    grid-template-columns: 1fr;
    gap: 30px;
}

@media (min-width: 768px) {
    #for-who .for-who-cards {
        grid-template-columns: repeat(3, 1fr);
    }
}

#for-who .card {
    background-color: white;
    padding: 25px;
    border-radius: 8px;
    box-shadow: 0 4px 6px rgba(0,0,0,0.1);
    text-align: center;
}

#for-who .card h3 {
    margin-top: 0;
    color: var(--primary-color);
}

/* Estilos para a imagem do autor */
.author-photo {
    width: 150px; /* Tamanho da foto */
    height: 150px; /* Para manter proporção quadrada */
    border-radius: 50%; /* Torna a imagem circular */
    display: block; /* Para poder centralizar com margin auto */
    margin: 0px auto 30px auto; /* Centraliza e adiciona margem inferior */
    box-shadow: 0 4px 10px rgba(0, 0, 0, 0.2); /* Sombra suave para destacar */
    object-fit: cover; /* Garante que a imagem preencha o círculo sem distorcer */
    border: 3px solid var(--dark-blue); /* Borda para destaque */
}

/* Ajuste o text-indent para o primeiro parágrafo após a foto */
#author .author-content p:first-of-type {
    text-indent: 0; /* Remove o recuo do primeiro parágrafo para não ficar estranho após a foto */
}

.fallback-form h3, .fallback-form p {
    text-align: center;
}

#fallback-button {
    display: block;
    width: 100%;
    padding: 15px 20px;
    background-color: var(--primary-color);
    color: white;
    border: none;
    border-radius: 4px;
    font-size: 1.1em;
    font-weight: bold;
    cursor: pointer;
    transition: background-color 0.3s;
    text-align: center;
}

#fallback-button:hover {
    background-color: #005bb5;
}

/* Alinha o texto à esquerda em telas maiores, mantendo a consistência do layout */
@media (min-width: 768px) {
    .fallback-form h3, .fallback-form p {
        text-align: left;
    }
}
footer {
    background-color: var(--dark-blue);
    color: var(--light-text);
    text-align: center;
    padding: 20px 0;
    margin-top: 40px;
}