/* ============================================
   VARIABLES CSS
   ============================================ */
:root {
    /* Colores Principales */
    --color-primary: #2563eb;
    --color-primary-dark: #1d4ed8;
    --color-primary-light: #3b82f6;
    --color-secondary: #10b981;
    --color-secondary-dark: #059669;
    
    /* Colores de Texto */
    --color-text: #1f2937;
    --color-text-light: #6b7280;
    --color-text-dark: #111827;
    
    /* Colores de Fondo */
    --color-bg: #ffffff;
    --color-bg-light: #f9fafb;
    --color-bg-gray: #f3f4f6;
    
    /* Colores de Estado */
    --color-success: #10b981;
    --color-warning: #f59e0b;
    --color-error: #ef4444;
    --color-info: #3b82f6;
    
    /* Sombras */
    --shadow-sm: 0 1px 2px 0 rgba(0, 0, 0, 0.05);
    --shadow-md: 0 4px 6px -1px rgba(0, 0, 0, 0.1);
    --shadow-lg: 0 10px 15px -3px rgba(0, 0, 0, 0.1);
    --shadow-xl: 0 20px 25px -5px rgba(0, 0, 0, 0.1);
    
    /* Espaciado */
    --spacing-xs: 0.25rem;
    --spacing-sm: 0.5rem;
    --spacing-md: 1rem;
    --spacing-lg: 1.5rem;
    --spacing-xl: 2rem;
    --spacing-2xl: 3rem;
    
    /* Border Radius */
    --radius-sm: 0.25rem;
    --radius-md: 0.5rem;
    --radius-lg: 0.75rem;
    --radius-xl: 1rem;
    
    /* Transiciones */
    --transition-fast: 150ms ease;
    --transition-base: 200ms ease;
    --transition-slow: 300ms ease;
    
    /* Tipografía */
    --font-sans: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, 'Helvetica Neue', Arial, sans-serif;
    --font-mono: 'Courier New', monospace;
}

/* ============================================
   RESET Y BASE
   ============================================ */
*, *::before, *::after {
    box-sizing: border-box;
    margin: 0;
    padding: 0;
}

html {
    font-size: 16px;
    -webkit-font-smoothing: antialiased;
    -moz-osx-font-smoothing: grayscale;
}

body {
    font-family: var(--font-sans);
    font-size: 1rem;
    line-height: 1.6;
    color: var(--color-text);
    background-color: var(--color-bg);
    overflow-x: hidden;
}

/* ============================================
   TIPOGRAFÍA
   ============================================ */
h1, h2, h3, h4, h5, h6 {
    font-weight: 700;
    line-height: 1.2;
    color: var(--color-text-dark);
    margin-bottom: var(--spacing-md);
}

h1 { font-size: 2.5rem; }
h2 { font-size: 2rem; }
h3 { font-size: 1.5rem; }
h4 { font-size: 1.25rem; }
h5 { font-size: 1.125rem; }
h6 { font-size: 1rem; }

p {
    margin-bottom: var(--spacing-md);
}

a {
    color: var(--color-primary);
    text-decoration: none;
    transition: color var(--transition-base);
}

a:hover {
    color: var(--color-primary-dark);
}

/* ============================================
   LAYOUT
   ============================================ */
.container {
    width: 100%;
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 var(--spacing-lg);
}

.section {
    padding: var(--spacing-2xl) 0;
}

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

/* ============================================
   HEADER Y NAVEGACIÓN
   ============================================ */
.header {
    background-color: var(--color-bg);
    box-shadow: var(--shadow-sm);
    position: sticky;
    top: 0;
    z-index: 100;
    transition: box-shadow var(--transition-base);
}

.header.scrolled {
    box-shadow: var(--shadow-md);
}

.nav {
    display: flex;
    align-items: center;
    justify-content: space-between;
    padding: var(--spacing-md) 0;
}

.logo {
    display: flex;
    align-items: center;
    gap: var(--spacing-sm);
    font-size: 1.5rem;
    font-weight: 700;
    color: var(--color-text-dark);
}

.logo-icon {
    font-size: 2rem;
}

.logo-highlight {
    color: var(--color-primary);
}

.nav-menu {
    display: flex;
    align-items: center;
    gap: var(--spacing-lg);
    list-style: none;
}

.nav-link {
    font-weight: 500;
    color: var(--color-text);
    padding: var(--spacing-sm) var(--spacing-md);
    border-radius: var(--radius-md);
    transition: all var(--transition-base);
}

.nav-link:hover {
    color: var(--color-primary);
    background-color: var(--color-bg-light);
}

.nav-link.active {
    color: var(--color-primary);
    background-color: var(--color-bg-light);
}

.nav-toggle {
    display: none;
    flex-direction: column;
    gap: 4px;
    background: none;
    border: none;
    cursor: pointer;
    padding: var(--spacing-sm);
}

.nav-toggle span {
    width: 24px;
    height: 2px;
    background-color: var(--color-text-dark);
    transition: all var(--transition-base);
}

/* ============================================
   HERO SECTION
   ============================================ */
.hero {
    background: linear-gradient(135deg, var(--color-primary) 0%, var(--color-primary-dark) 100%);
    color: white;
    padding: var(--spacing-2xl) 0;
    text-align: center;
}

.hero-content {
    max-width: 800px;
    margin: 0 auto;
}

.hero-title {
    font-size: 3rem;
    margin-bottom: var(--spacing-lg);
    color: white;
}

.hero-subtitle {
    font-size: 1.25rem;
    margin-bottom: var(--spacing-xl);
    opacity: 0.95;
}

.highlight {
    color: var(--color-secondary);
}

.hero-cta {
    display: flex;
    gap: var(--spacing-md);
    justify-content: center;
    flex-wrap: wrap;
}

/* ============================================
   BOTONES
   ============================================ */
.btn {
    display: inline-block;
    padding: var(--spacing-md) var(--spacing-xl);
    font-weight: 600;
    font-size: 1rem;
    border-radius: var(--radius-md);
    border: none;
    cursor: pointer;
    text-align: center;
    transition: all var(--transition-base);
    text-decoration: none;
}

.btn-primary {
    background-color: var(--color-secondary);
    color: white;
}

.btn-primary:hover {
    background-color: var(--color-secondary-dark);
    transform: translateY(-2px);
    box-shadow: var(--shadow-lg);
}

.btn-secondary {
    background-color: white;
    color: var(--color-primary);
}

.btn-secondary:hover {
    background-color: var(--color-bg-light);
    transform: translateY(-2px);
}

.btn-large {
    padding: var(--spacing-lg) var(--spacing-2xl);
    font-size: 1.125rem;
}

/* ============================================
   SECTION HEADERS
   ============================================ */
.section-header {
    text-align: center;
    margin-bottom: var(--spacing-2xl);
}

.section-title {
    font-size: 2.5rem;
    margin-bottom: var(--spacing-md);
}

.section-subtitle {
    font-size: 1.125rem;
    color: var(--color-text-light);
    max-width: 600px;
    margin: 0 auto;
}

/* ============================================
   CALCULADORAS GRID
   ============================================ */
.calculadoras-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(300px, 1fr));
    gap: var(--spacing-xl);
}

.calculadora-card {
    background-color: var(--color-bg);
    border-radius: var(--radius-lg);
    padding: var(--spacing-xl);
    box-shadow: var(--shadow-md);
    transition: all var(--transition-base);
    display: flex;
    flex-direction: column;
}

.calculadora-card:hover {
    transform: translateY(-4px);
    box-shadow: var(--shadow-xl);
}

.calculadora-card.featured {
    border: 2px solid var(--color-primary);
    position: relative;
}

.calculadora-card.featured::before {
    content: "⭐ Destacada";
    position: absolute;
    top: -12px;
    left: 50%;
    transform: translateX(-50%);
    background-color: var(--color-primary);
    color: white;
    padding: var(--spacing-xs) var(--spacing-md);
    border-radius: var(--radius-md);
    font-size: 0.875rem;
    font-weight: 600;
}

.card-icon {
    font-size: 3rem;
    margin-bottom: var(--spacing-md);
}

.card-title {
    font-size: 1.5rem;
    margin-bottom: var(--spacing-md);
}

.card-description {
    color: var(--color-text-light);
    margin-bottom: var(--spacing-md);
    flex-grow: 1;
}

.card-tags {
    display: flex;
    gap: var(--spacing-sm);
    margin-bottom: var(--spacing-md);
    flex-wrap: wrap;
}

.tag {
    font-size: 0.75rem;
    padding: var(--spacing-xs) var(--spacing-sm);
    background-color: var(--color-bg-gray);
    color: var(--color-text);
    border-radius: var(--radius-sm);
    font-weight: 500;
}

.card-link {
    font-weight: 600;
    color: var(--color-primary);
    display: inline-flex;
    align-items: center;
    gap: var(--spacing-sm);
}

.card-link:hover {
    color: var(--color-primary-dark);
}

/* ============================================
   ADSENSE CONTAINERS
   ============================================ */
.ad-container {
    padding: var(--spacing-xl) 0;
    display: flex;
    justify-content: center;
}

.adsbygoogle {
    display: block;
    min-height: 100px;
    background-color: var(--color-bg-gray);
}

/* ============================================
   CTA SECTION
   ============================================ */
.cta-section {
    background: linear-gradient(135deg, var(--color-primary) 0%, var(--color-primary-dark) 100%);
    color: white;
    padding: var(--spacing-2xl) 0;
    text-align: center;
}

.cta-content {
    max-width: 700px;
    margin: 0 auto;
}

.cta-title {
    color: white;
    font-size: 2rem;
    margin-bottom: var(--spacing-md);
}

.cta-text {
    font-size: 1.125rem;
    margin-bottom: var(--spacing-xl);
    opacity: 0.95;
}

/* ============================================
   FOOTER
   ============================================ */
.footer {
    background-color: var(--color-text-dark);
    color: white;
    padding: var(--spacing-2xl) 0 var(--spacing-lg);
}

.footer-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
    gap: var(--spacing-xl);
    margin-bottom: var(--spacing-xl);
}

.footer-title {
    font-size: 1.5rem;
    margin-bottom: var(--spacing-md);
    color: white;
}

.footer-text {
    color: rgba(255, 255, 255, 0.8);
    line-height: 1.6;
}

.footer-heading {
    font-size: 1.125rem;
    margin-bottom: var(--spacing-md);
    color: white;
}

.footer-links {
    list-style: none;
}

.footer-links li {
    margin-bottom: var(--spacing-sm);
}

.footer-links a {
    color: rgba(255, 255, 255, 0.8);
    transition: color var(--transition-base);
}

.footer-links a:hover {
    color: white;
}

.social-links {
    display: flex;
    gap: var(--spacing-md);
}

.social-link {
    display: flex;
    align-items: center;
    justify-content: center;
    width: 40px;
    height: 40px;
    background-color: rgba(255, 255, 255, 0.1);
    border-radius: var(--radius-md);
    color: white;
    font-weight: 600;
    transition: all var(--transition-base);
}

.social-link:hover {
    background-color: var(--color-primary);
    transform: translateY(-2px);
}

.footer-bottom {
    border-top: 1px solid rgba(255, 255, 255, 0.1);
    padding-top: var(--spacing-lg);
    text-align: center;
    color: rgba(255, 255, 255, 0.7);
}

.footer-disclaimer {
    font-size: 0.875rem;
    margin-top: var(--spacing-sm);
}

/* ============================================
   RESPONSIVE DESIGN
   ============================================ */

/* Tablets */
@media (max-width: 768px) {
    html {
        font-size: 14px;
    }
    
    .nav-menu {
        position: fixed;
        top: 70px;
        left: 0;
        right: 0;
        background-color: var(--color-bg);
        flex-direction: column;
        padding: var(--spacing-lg);
        box-shadow: var(--shadow-lg);
        transform: translateY(-100%);
        opacity: 0;
        visibility: hidden;
        transition: all var(--transition-base);
    }
    
    .nav-menu.active {
        transform: translateY(0);
        opacity: 1;
        visibility: visible;
    }
    
    .nav-toggle {
        display: flex;
    }
    
    .nav-toggle.active span:nth-child(1) {
        transform: rotate(45deg) translate(5px, 5px);
    }
    
    .nav-toggle.active span:nth-child(2) {
        opacity: 0;
    }
    
    .nav-toggle.active span:nth-child(3) {
        transform: rotate(-45deg) translate(5px, -5px);
    }
    
    .hero-title {
        font-size: 2rem;
    }
    
    .section-title {
        font-size: 2rem;
    }
    
    .calculadoras-grid {
        grid-template-columns: 1fr;
    }
}

/* Mobile */
@media (max-width: 480px) {
    .container {
        padding: 0 var(--spacing-md);
    }
    
    .hero-cta {
        flex-direction: column;
    }
    
    .btn {
        width: 100%;
    }
}

/* ============================================
   UTILIDADES
   ============================================ */
.text-center {
    text-align: center;
}

.text-left {
    text-align: left;
}

.text-right {
    text-align: right;
}

.mt-sm { margin-top: var(--spacing-sm); }
.mt-md { margin-top: var(--spacing-md); }
.mt-lg { margin-top: var(--spacing-lg); }
.mt-xl { margin-top: var(--spacing-xl); }

.mb-sm { margin-bottom: var(--spacing-sm); }
.mb-md { margin-bottom: var(--spacing-md); }
.mb-lg { margin-bottom: var(--spacing-lg); }
.mb-xl { margin-bottom: var(--spacing-xl); }

.hidden {
    display: none;
}

.visible {
    display: block;
}

/* ============================================
   ANIMACIONES
   ============================================ */
@keyframes fadeIn {
    from {
        opacity: 0;
        transform: translateY(20px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

.fade-in {
    animation: fadeIn 0.5s ease;
}