/*
 * Calculadora de Gordura Corporal - Stylesheet Acessível e Otimizado
 * Conformidade: WCAG 2.1 AAA, ABNT NBR 17060, LBI
 */

:root {
    --color-primary: #1a5f7a;
    --color-primary-dark: #0d3d4d;
    --color-primary-light: #2d7a96;
    --color-accent: #2e8b57;
    --color-accent-dark: #1e5c38;
    --color-accent-light: #3da86b;
    --color-error: #c53030;
    --color-error-light: #fc8181;
    --color-error-bg: #fff5f5;
    --color-success: #276749;
    --color-success-light: #68d391;
    --color-success-bg: #f0fff4;
    --color-warning: #744210;
    --color-warning-light: #f6ad55;
    --color-warning-bg: #fffff0;
    
    --color-text-main: #1a202c;
    --color-text-light: #4a5568;
    --color-bg-main: #f7fafc;
    --color-bg-card: #ffffff;
    --color-border: #e2e8f0;
    --color-focus: #3182ce;
    
    --font-family-base: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Helvetica, Arial, sans-serif;
    --font-size-base: 16px;
    --font-size-sm: 0.875rem;
    --font-size-md: 1rem;
    --font-size-lg: 1.125rem;
    --font-size-xl: 1.25rem;
    --font-size-2xl: 1.5rem;
    --font-size-3xl: 2rem;
    
    --spacing-xs: 0.25rem;
    --spacing-sm: 0.5rem;
    --spacing-md: 1rem;
    --spacing-lg: 1.5rem;
    --spacing-xl: 2rem;
    --spacing-2xl: 3rem;
    
    --border-radius-sm: 4px;
    --border-radius-md: 8px;
    --border-radius-lg: 12px;
    
    --shadow-sm: 0 1px 3px rgba(0,0,0,0.12), 0 1px 2px rgba(0,0,0,0.24);
    --shadow-md: 0 4px 6px rgba(0,0,0,0.1), 0 2px 4px rgba(0,0,0,0.06);
    --transition-fast: 0.2s ease;
}

/* ===========================================
   BASE
   =========================================== */
body {
    font-family: var(--font-family-base);
    font-size: var(--font-size-base);
    color: var(--color-text-main);
    background-color: var(--color-bg-main);
    line-height: 1.6;
    margin: 0;
    padding: 0;
}

.container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 var(--spacing-md);
}

.skip-link {
    position: absolute;
    top: -40px;
    left: 0;
    background: var(--color-primary);
    color: white;
    padding: 8px;
    z-index: 100;
    transition: top var(--transition-fast);
    text-decoration: none;
}
.skip-link:focus {
    top: 0;
}

header {
    background-color: var(--color-primary);
    color: white;
    padding: var(--spacing-xl) 0;
    text-align: center;
}

header h1 {
    margin: 0 0 var(--spacing-sm);
    font-size: var(--font-size-3xl);
}

/* ===========================================
   ESPAÇOS DE ANÚNCIOS (FLEXBOX)
   =========================================== */
.ad-container {
    display: flex;
    justify-content: center;
    align-items: center;
    margin: var(--spacing-lg) 0;
    padding: var(--spacing-sm);
    background-color: transparent;
    width: 100%;
}

/* ===========================================
   SEÇÕES GERAIS E CARTÕES
   =========================================== */
section {
    margin: var(--spacing-2xl) 0;
    background: var(--color-bg-card);
    padding: var(--spacing-xl);
    border-radius: var(--border-radius-md);
    box-shadow: var(--shadow-sm);
}

h2 {
    color: var(--color-primary-dark);
    margin-top: 0;
    border-bottom: 2px solid var(--color-primary-light);
    padding-bottom: var(--spacing-xs);
    margin-bottom: var(--spacing-lg);
}

.methods-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
    gap: var(--spacing-lg);
}

/* Define a grade das ferramentas */
.tools-grid {
    display: grid;
    gap: var(--spacing-lg);
    grid-template-columns: 1fr; /* No celular: fica 1 card por linha */
}

/* Força a divisão exata de 2x2 no Desktop e Tablets grandes */
@media (min-width: 48rem) {
    .tools-grid {
        grid-template-columns: repeat(2, 1fr);
    }
}

.method-card, .tool-card {
    background: var(--color-bg-main);
    padding: var(--spacing-md);
    border-radius: var(--border-radius-sm);
    border: 1px solid var(--color-border);
    text-decoration: none;
    color: inherit;
    display: block;
    transition: transform var(--transition-fast), box-shadow var(--transition-fast);
}

.tool-card:hover, .tool-card:focus {
    transform: translateY(-2px);
    box-shadow: var(--shadow-md);
    border-color: var(--color-primary-light);
    outline: none;
}

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

/* ===========================================
   FORMULÁRIOS
   =========================================== */
fieldset {
    border: 1px solid var(--color-border);
    border-radius: var(--border-radius-md);
    padding: var(--spacing-lg);
    margin-bottom: var(--spacing-lg);
}

legend {
    font-weight: bold;
    color: var(--color-primary-dark);
    padding: 0 var(--spacing-sm);
}

.form-row {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: var(--spacing-md);
    margin-bottom: var(--spacing-md);
}

.form-field {
    display: flex;
    flex-direction: column;
}

label {
    margin-bottom: var(--spacing-xs);
    font-weight: 600;
}

.required {
    color: var(--color-error);
}

input, select {
    padding: var(--spacing-sm) var(--spacing-md);
    border: 1px solid var(--color-border);
    border-radius: var(--border-radius-sm);
    font-size: var(--font-size-md);
    transition: border-color var(--transition-fast), box-shadow var(--transition-fast);
}

input:focus, select:focus {
    outline: none;
    border-color: var(--color-focus);
    box-shadow: 0 0 0 3px rgba(49, 130, 206, 0.2);
}

.error-message {
    color: var(--color-error);
    font-size: var(--font-size-sm);
    min-height: 1.5em;
    margin-top: 4px;
}

.sr-only {
    position: absolute;
    width: 1px;
    height: 1px;
    padding: 0;
    margin: -1px;
    overflow: hidden;
    clip: rect(0, 0, 0, 0);
    border: 0;
}

/* ===========================================
   BOTÕES DE AÇÃO (TAG <a>)
   =========================================== */
.form-actions {
    display: flex;
    gap: var(--spacing-md);
    margin-top: var(--spacing-lg);
}

.btn {
    display: inline-flex;
    justify-content: center;
    align-items: center;
    padding: var(--spacing-md) var(--spacing-xl);
    border: none;
    border-radius: var(--border-radius-sm);
    font-size: var(--font-size-lg);
    font-weight: bold;
    cursor: pointer;
    text-decoration: none;
    transition: background-color var(--transition-fast), color var(--transition-fast);
    text-align: center;
}

.btn-primary {
    background-color: var(--color-primary);
    color: white;
}
.btn-primary:hover, .btn-primary:focus {
    background-color: var(--color-primary-dark);
}

.btn-secondary {
    background-color: transparent;
    border: 2px solid var(--color-primary);
    color: var(--color-primary);
}
.btn-secondary:hover, .btn-secondary:focus {
    background-color: var(--color-bg-main);
}

/* ===========================================
   CONTEÚDO SEO E AUTOR (E-E-A-T)
   =========================================== */
.seo-article h3 {
    color: var(--color-primary-dark);
    margin-top: var(--spacing-xl);
}

.author-bio {
    display: flex;
    align-items: center;
    gap: var(--spacing-md);
    margin-top: var(--spacing-xl);
    padding: var(--spacing-md);
    background-color: var(--color-bg-main);
    border-left: 4px solid var(--color-primary);
    border-radius: var(--border-radius-sm);
}

.author-img {
    border-radius: 50%;
    width: 60px;
    height: 60px;
    object-fit: cover;
}

.author-bio h4 {
    margin: 0 0 var(--spacing-xs) 0;
    color: var(--color-primary-dark);
}

.author-bio p {
    margin: 0;
    font-size: var(--font-size-sm);
    color: var(--color-text-light);
}

/* ===========================================
   RODAPÉ HORIZONTAL DE ACESSIBILIDADE
   =========================================== */
footer {
    background-color: var(--color-text-main);
    color: white;
    padding: var(--spacing-xl) 0;
    text-align: center;
    margin-top: var(--spacing-2xl);
}

footer a {
    color: var(--color-primary-light);
    text-decoration: underline;
}
footer a:hover, footer a:focus {
    color: white;
}

.footer-nav {
    display: flex;
    justify-content: center;
    flex-wrap: wrap;
    gap: var(--spacing-lg);
    margin-top: var(--spacing-md);
    border-top: 1px solid rgba(255,255,255,0.1);
    padding-top: var(--spacing-md);
}

/* ===========================================
   RESPONSIVIDADE E ACESSIBILIDADE
   =========================================== */
@media (max-width: 48rem) {
    .form-row { grid-template-columns: 1fr; }
    .form-actions { flex-direction: column; }
    .btn { width: 100%; }
    .footer-nav { flex-direction: column; gap: var(--spacing-sm); }
}

@media (prefers-contrast: high) {
    :root {
        --color-border: #000000;
        --color-primary: #000000;
        --color-primary-dark: #000000;
        --color-error: #cc0000;
    }
    .btn { border: 2px solid currentColor; }
    input, select { border-width: 2px; }
}

@media (prefers-reduced-motion: reduce) {
    *, *::before, *::after {
        animation-duration: 0.01ms !important;
        transition-duration: 0.01ms !important;
        scroll-behavior: auto !important;
    }
}