/* ==========================================================================
   CSS PRINCIPAL - CALCULADORA ISR, AGUINALDO Y FINIQUITO MÉXICO
   ========================================================================== */

:root {
    /* Paleta de Colores Moderna (Dark Mode Por Defecto) */
    --bg-primary: #0f172a;
    --bg-secondary: #1e293b;
    --bg-card: rgba(30, 41, 59, 0.75);
    --bg-glass: rgba(15, 23, 42, 0.65);
    --border-color: rgba(255, 255, 255, 0.1);
    --border-highlight: rgba(59, 130, 246, 0.3);

    --text-primary: #f8fafc;
    --text-secondary: #94a3b8;
    --text-muted: #64748b;

    /* Acentos */
    --accent-green: #10b981;
    --accent-green-hover: #059669;
    --accent-blue: #3b82f6;
    --accent-blue-hover: #2563eb;
    --accent-purple: #8b5cf6;
    --accent-amber: #f59e0b;
    --accent-red: #ef4444;

    /* Sombras y Efectos */
    --shadow-sm: 0 2px 4px rgba(0, 0, 0, 0.2);
    --shadow-md: 0 4px 12px rgba(0, 0, 0, 0.3);
    --shadow-lg: 0 10px 25px -5px rgba(0, 0, 0, 0.4), 0 8px 10px -6px rgba(0, 0, 0, 0.3);
    --glow-green: 0 0 20px rgba(16, 185, 129, 0.25);
    --glow-blue: 0 0 20px rgba(59, 130, 246, 0.25);

    --radius-sm: 8px;
    --radius-md: 14px;
    --radius-lg: 20px;
    --radius-full: 9999px;

    --font-heading: 'Outfit', -apple-system, BlinkMacSystemFont, sans-serif;
    --font-body: 'Plus Jakarta Sans', -apple-system, BlinkMacSystemFont, sans-serif;
    --transition: all 0.25s cubic-bezier(0.4, 0, 0.2, 1);
}

/* Modo Claro (Light Theme Class) */
body.light-theme {
    --bg-primary: #f1f5f9;
    --bg-secondary: #ffffff;
    --bg-card: rgba(255, 255, 255, 0.85);
    --bg-glass: rgba(255, 255, 255, 0.7);
    --border-color: rgba(0, 0, 0, 0.08);
    --border-highlight: rgba(59, 130, 246, 0.4);

    --text-primary: #0f172a;
    --text-secondary: #475569;
    --text-muted: #94a3b8;

    --shadow-sm: 0 1px 3px rgba(0, 0, 0, 0.05);
    --shadow-md: 0 4px 6px -1px rgba(0, 0, 0, 0.07);
    --shadow-lg: 0 10px 15px -3px rgba(0, 0, 0, 0.1);
}

/* Reset Global */
*, *::before, *::after {
    box-sizing: border-box;
    margin: 0;
    padding: 0;
}

body {
    font-family: var(--font-body);
    background-color: var(--bg-primary);
    color: var(--text-primary);
    line-height: 1.6;
    overflow-x: hidden;
    min-height: 100vh;
    display: flex;
    flex-direction: column;
}

/* Encabezado Principal */
.header-navbar {
    background: var(--bg-card);
    backdrop-filter: blur(16px);
    -webkit-backdrop-filter: blur(16px);
    border-bottom: 1px solid var(--border-color);
    position: sticky;
    top: 0;
    z-index: 100;
    padding: 0.8rem 1.5rem;
}

.header-container {
    max-width: 1280px;
    margin: 0 auto;
    display: flex;
    align-items: center;
    justify-content: space-between;
}

.brand-logo {
    display: flex;
    align-items: center;
    gap: 0.75rem;
    text-decoration: none;
    color: var(--text-primary);
    font-family: var(--font-heading);
    font-weight: 700;
    font-size: 1.35rem;
}

.brand-logo i {
    color: var(--accent-green);
    font-size: 1.6rem;
    filter: drop-shadow(0 0 8px rgba(16, 185, 129, 0.4));
}

.brand-badge {
    background: linear-gradient(135deg, var(--accent-green), var(--accent-blue));
    color: #ffffff;
    font-size: 0.7rem;
    font-weight: 700;
    padding: 0.2rem 0.6rem;
    border-radius: var(--radius-full);
    text-transform: uppercase;
    letter-spacing: 0.5px;
}

.nav-actions {
    display: flex;
    align-items: center;
    gap: 1rem;
}

.theme-toggle-btn {
    background: var(--bg-secondary);
    border: 1px solid var(--border-color);
    color: var(--text-primary);
    padding: 0.5rem 1rem;
    border-radius: var(--radius-md);
    cursor: pointer;
    font-size: 0.9rem;
    font-weight: 600;
    display: flex;
    align-items: center;
    gap: 0.5rem;
    transition: var(--transition);
}

.theme-toggle-btn:hover {
    border-color: var(--accent-blue);
    transform: translateY(-2px);
    box-shadow: var(--shadow-sm);
}

/* Layout Principal */
.main-wrapper {
    max-width: 1280px;
    margin: 1.5rem auto 3rem;
    padding: 0 1rem;
    flex: 1;
    width: 100%;
}

/* Navegación por Pestañas (Tabs) */
.tabs-navigation {
    display: flex;
    align-items: center;
    gap: 0.5rem;
    background: var(--bg-card);
    padding: 0.5rem;
    border-radius: var(--radius-lg);
    border: 1px solid var(--border-color);
    margin-bottom: 2rem;
    overflow-x: auto;
    scrollbar-width: thin;
}

.tab-btn {
    flex: 1;
    min-width: 140px;
    padding: 0.85rem 1.2rem;
    border: none;
    background: transparent;
    color: var(--text-secondary);
    font-family: var(--font-heading);
    font-weight: 600;
    font-size: 0.95rem;
    border-radius: var(--radius-md);
    cursor: pointer;
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 0.6rem;
    transition: var(--transition);
    white-space: nowrap;
}

.tab-btn i {
    font-size: 1.1rem;
}

.tab-btn:hover {
    color: var(--text-primary);
    background: rgba(255, 255, 255, 0.04);
}

.tab-btn.active {
    background: linear-gradient(135deg, var(--accent-blue), var(--accent-green));
    color: #ffffff;
    box-shadow: var(--glow-blue);
}

/* Contenido de las Pestañas */
.tab-pane {
    display: none;
    animation: fadeIn 0.35s ease-in-out;
}

.tab-pane.active {
    display: block;
}

@keyframes fadeIn {
    from { opacity: 0; transform: translateY(8px); }
    to { opacity: 1; transform: translateY(0); }
}

/* Pie de Página */
.site-footer {
    background: var(--bg-secondary);
    border-top: 1px solid var(--border-color);
    padding: 2.5rem 1.5rem 6rem; /* Espacio extra para el sticky ad footer */
    margin-top: auto;
}

.footer-container {
    max-width: 1280px;
    margin: 0 auto;
    display: flex;
    flex-wrap: wrap;
    justify-content: space-between;
    align-items: center;
    gap: 1.5rem;
}

.footer-info {
    color: var(--text-muted);
    font-size: 0.9rem;
}

.footer-disclaimer {
    max-width: 600px;
    font-size: 0.8rem;
    color: var(--text-muted);
    line-height: 1.4;
    border-left: 3px solid var(--accent-amber);
    padding-left: 0.8rem;
}

@media (max-width: 768px) {
    .header-container { flex-direction: column; gap: 0.75rem; }
    .tabs-navigation { justify-content: flex-start; }
    .tab-btn { min-width: 120px; font-size: 0.85rem; padding: 0.7rem 0.9rem; }
}