/* Estilos Globais e Reset Básico */
* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

:root {
    --primary-color: #007bff;
    --secondary-color: #6c757d;
    --success-color: #28a745;
    --danger-color: #dc3545;
    --warning-color: #ffc107;
    --info-color: #17a2b8;
    --light-color: #f8f9fa;
    --dark-color: #343a40;
    --text-color: #212529;
    --background-color: #ffffff;
    --border-color: #dee2e6;
    --link-color: #007bff;
    --font-family-sans-serif: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial, "Noto Sans", sans-serif, "Apple Color Emoji", "Segoe UI Emoji", "Segoe UI Symbol", "Noto Color Emoji";
    --font-family-monospace: SFMono-Regular, Menlo, Monaco, Consolas, "Liberation Mono", "Courier New", monospace;
}

body {
    font-family: var(--font-family-sans-serif);
    font-size: 1rem;
    font-weight: 400;
    line-height: 1.5;
    color: var(--text-color);
    background-color: var(--background-color);
    transition: background-color 0.3s ease, color 0.3s ease;
}

h1, h2, h3, h4, h5, h6 {
    margin-top: 0;
    margin-bottom: 0.5rem;
    font-weight: 500;
    line-height: 1.2;
}

h1 { font-size: 2.5rem; }
h2 { font-size: 2rem; }
h3 { font-size: 1.75rem; }
h4 { font-size: 1.5rem; }
h5 { font-size: 1.25rem; }
h6 { font-size: 1rem; }

p {
    margin-top: 0;
    margin-bottom: 1rem;
}

a {
    color: var(--link-color);
    text-decoration: none;
    background-color: transparent;
    transition: color 0.15s ease-in-out, background-color 0.15s ease-in-out, border-color 0.15s ease-in-out;
}

a:hover {
    color: #0056b3;
    text-decoration: underline;
}

.container {
    width: 100%;
    padding-right: 15px;
    padding-left: 15px;
    margin-right: auto;
    margin-left: auto;
}

/* Utilitários */
.text-center { text-align: center; }
.mb-3 { margin-bottom: 1rem !important; }

/* Botões */
.btn {
    display: inline-block;
    font-weight: 400;
    color: #212529;
    text-align: center;
    vertical-align: middle;
    cursor: pointer;
    -webkit-user-select: none;
    -moz-user-select: none;
    -ms-user-select: none;
    user-select: none;
    background-color: transparent;
    border: 1px solid transparent;
    padding: 0.375rem 0.75rem;
    font-size: 1rem;
    line-height: 1.5;
    border-radius: 0.25rem;
    transition: color 0.15s ease-in-out, background-color 0.15s ease-in-out, border-color 0.15s ease-in-out, box-shadow 0.15s ease-in-out;
}

.btn-primary {
    color: #fff;
    background-color: var(--primary-color);
    border-color: var(--primary-color);
}

.btn-primary:hover {
    color: #fff;
    background-color: #0069d9;
    border-color: #0062cc;
    text-decoration: none;
}

.btn-secondary {
    color: #fff;
    background-color: var(--secondary-color);
    border-color: var(--secondary-color);
}

.btn-secondary:hover {
    color: #fff;
    background-color: #5a6268;
    border-color: #545b62;
    text-decoration: none;
}

/* Estilos da Landing Page (index.php) */
.landing-header {
    background-color: var(--dark-color);
    color: var(--light-color);
    padding: 4rem 0;
    text-align: center;
}

.landing-header h1 {
    font-size: 3rem;
    margin-bottom: 1rem;
}

.landing-about,
.landing-cta {
    padding: 3rem 0;
    text-align: center;
}

.landing-about {
    background-color: var(--light-color);
}

.landing-cta .btn {
    font-size: 1.2rem;
    padding: 0.8rem 1.5rem;
}

.landing-footer {
    background-color: var(--dark-color);
    color: var(--light-color);
    padding: 1.5rem 0;
    text-align: center;
    font-size: 0.9em;
}

/* Estilos do Formulário de Login (login.php) - Refinando */
.login-container {
    background-color: var(--background-color);
    padding: 30px;
    border-radius: 8px;
    box-shadow: 0 0 15px rgba(0,0,0,0.1);
    width: 100%;
    max-width: 400px;
    text-align: center;
    border: 1px solid var(--border-color);
}

.login-container h2 {
    margin-bottom: 20px;
    color: var(--text-color);
}

.form-group {
    margin-bottom: 15px;
    text-align: left;
}

.form-group label {
    display: block;
    margin-bottom: 5px;
    color: var(--secondary-color);
}

.form-group input {
    width: 100%;
    padding: 10px;
    border: 1px solid var(--border-color);
    border-radius: 4px;
    box-sizing: border-box;
    background-color: var(--background-color);
    color: var(--text-color);
}

.form-group .invalid-feedback {
    color: var(--danger-color);
    font-size: 0.9em;
    margin-top: 5px;
}

.login-container .btn {
    background-color: var(--primary-color);
    color: white;
    padding: 12px 20px;
    border: none;
    border-radius: 4px;
    cursor: pointer;
    width: 100%;
    font-size: 16px;
    transition: background-color 0.3s ease;
}

.login-container .btn:hover {
    background-color: #0056b3;
}

.alert {
    padding: 10px;
    margin-bottom: 15px;
    border: 1px solid transparent;
    border-radius: 4px;
}

.alert-danger {
    color: #721c24;
    background-color: #f8d7da;
    border-color: #f5c6cb;
}

/* Estilos Base do Painel Admin (admin_panel.php) */
.navbar {
    background-color: var(--dark-color);
    padding: 10px 20px;
    color: white;
    display: flex;
    justify-content: space-between;
    align-items: center;
    border-bottom: 1px solid #495057;
}

.navbar h1 { margin: 0; font-size: 1.5em; }

.navbar .user-info span {
    margin-right: 15px;
}

.navbar a.logout-link {
    color: var(--warning-color);
    text-decoration: none;
    padding: 8px 15px;
    border-radius: 4px;
    border: 1px solid var(--warning-color);
    transition: background-color 0.3s ease, color 0.3s ease;
}

.navbar a.logout-link:hover {
    background-color: var(--warning-color);
    color: var(--dark-color);
    text-decoration: none;
}

.admin-container {
    display: flex;
    min-height: calc(100vh - 57px); /* Altura total menos a altura da navbar */
}

.sidebar {
    width: 250px;
    background-color: #e9ecef; /* Cor de fundo da sidebar */
    padding: 20px;
    border-right: 1px solid var(--border-color);
    transition: background-color 0.3s ease;
}

.sidebar h3 {
    color: var(--secondary-color);
    margin-bottom: 20px;
    font-size: 1.2em;
}

.sidebar ul {
    list-style: none;
    padding: 0;
}

.sidebar ul li a {
    display: block;
    padding: 10px 15px;
    color: var(--text-color);
    text-decoration: none;
    border-radius: 4px;
    margin-bottom: 5px;
    transition: background-color 0.2s ease, color 0.2s ease;
}

.sidebar ul li a:hover,
.sidebar ul li a.active {
    background-color: var(--primary-color);
    color: white;
    text-decoration: none;
}

.main-content {
    flex-grow: 1;
    padding: 30px;
    background-color: var(--background-color);
    transition: background-color 0.3s ease;
}

.welcome-message {
    margin-bottom: 20px;
    font-size: 1.2em;
    padding: 15px;
    background-color: var(--light-color);
    border: 1px solid var(--border-color);
    border-radius: 5px;
}

/* Responsividade */
@media (min-width: 576px) {
    .container {
        max-width: 540px;
    }
}

@media (min-width: 768px) {
    .container {
        max-width: 720px;
    }
}

@media (min-width: 992px) {
    .container {
        max-width: 960px;
    }
    .sidebar {
        display: block; /* Mostra sidebar em telas maiores */
    }
}

@media (min-width: 1200px) {
    .container {
        max-width: 1140px;
    }
}

@media (max-width: 991.98px) {
    .admin-container {
        flex-direction: column;
    }
    .sidebar {
        width: 100%;
        border-right: none;
        border-bottom: 1px solid var(--border-color);
        /* Adicionar botão para mostrar/esconder sidebar em mobile? */
    }
    .main-content {
        padding: 20px;
    }
    .navbar {
        flex-direction: column;
        align-items: flex-start;
    }
    .navbar .user-info {
        margin-top: 10px;
        width: 100%;
        display: flex;
        justify-content: space-between;
    }
}

/* Modo Escuro (Exemplo Básico com Classe no Body) */
body.dark-mode {
    --text-color: #e9ecef;
    --background-color: #212529;
    --border-color: #495057;
    --light-color: #343a40; /* Invertido para fundos claros no modo escuro */
    --dark-color: #f8f9fa;  /* Invertido para texto claro no modo escuro */
}

body.dark-mode a {
    color: #61daff; /* Cor de link ajustada para modo escuro */
}

body.dark-mode a:hover {
    color: #8c Bfff;
}

body.dark-mode .landing-header,
body.dark-mode .landing-footer {
    background-color: #1a1d20; /* Um pouco mais escuro que o fundo */
    color: #e9ecef;
}

body.dark-mode .landing-about {
    background-color: #2c3034;
}

body.dark-mode .login-container {
    background-color: #343a40;
    border-color: #495057;
    box-shadow: 0 0 15px rgba(255,255,255,0.05);
}

body.dark-mode .login-container h2,
body.dark-mode .form-group label {
    color: #ced4da;
}

body.dark-mode .form-group input {
    background-color: #495057;
    border-color: #6c757d;
    color: #f8f9fa;
}

body.dark-mode .alert-danger {
    color: #f5c6cb;
    background-color: #721c24;
    border-color: #f5c6cb;
}

body.dark-mode .navbar {
    background-color: #1a1d20;
    border-bottom-color: #495057;
    color: #f8f9fa;
}

body.dark-mode .navbar a.logout-link {
    color: var(--warning-color);
    border-color: var(--warning-color);
}

body.dark-mode .navbar a.logout-link:hover {
    background-color: var(--warning-color);
    color: #212529;
}

body.dark-mode .sidebar {
    background-color: #2c3034;
    border-right-color: #495057;
}

body.dark-mode .sidebar h3 {
    color: #adb5bd;
}

body.dark-mode .sidebar ul li a {
    color: #ced4da;
}

body.dark-mode .sidebar ul li a:hover,
body.dark-mode .sidebar ul li a.active {
    background-color: var(--primary-color);
    color: white;
}

body.dark-mode .main-content {
    background-color: #212529;
}

body.dark-mode .welcome-message {
    background-color: #343a40;
    border-color: #495057;
    color: #e9ecef;
}

/* Adicionar mais estilos específicos conforme necessário */