/* ==========================================================================
   NEXCELL Metabolic Wellness - Style Architecture (Optimizado)
   Theme: Premium Dark Cyber-Gold (Longevity + High-Tech Biotechnology)
   ========================================================================== */

:root {
    --bg-main: #0a0c10;
    --bg-card: #121620;
    --bg-card-hover: #1a202c;
    --gold-primary: #D4AF37;
    --gold-gradient: linear-gradient(135deg, #F3E5AB 0%, #D4AF37 50%, #AA7C11 100%);
    --silver-accent: #E2E8F0;
    --text-primary: #F8FAFC;
    --text-secondary: #94A3B8;
    --text-dark: #0f172a;
    --border-color: rgba(212, 175, 55, 0.2);
    --border-light: rgba(255, 255, 255, 0.08);
    --font-main: 'Plus Jakarta Sans', -apple-system, BlinkMacSystemFont, sans-serif;
    --transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
    --container-width: 1200px;
}

/* Reset & Global Standards */
* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

html {
    scroll-behavior: smooth;
    font-size: 16px;
}

body {
    font-family: var(--font-main);
    background-color: var(--bg-main);
    color: var(--text-primary);
    line-height: 1.6;
    overflow-x: hidden;
}

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

ul {
    list-style: none;
}

img {
    max-width: 100%;
    height: auto;
    display: block;
}

/* Layout & Utilities */
.container {
    width: 90%;
    max-width: var(--container-width);
    margin: 0 auto;
}

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

.sub-heading {
    text-transform: uppercase;
    font-size: 0.85rem;
    letter-spacing: 2.5px;
    font-weight: 700;
    color: var(--gold-primary);
    margin-bottom: 0.5rem;
    display: block;
}

.section-title {
    font-size: 2.5rem;
    font-weight: 800;
    line-height: 1.2;
    margin-bottom: 1rem;
    color: var(--text-primary);
}

.text-gradient {
    background: var(--gold-gradient);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
}

.grid {
    display: grid;
    gap: 2rem;
}

.grid-2-col { grid-template-columns: repeat(2, 1fr); }
.grid-3-col { grid-template-columns: repeat(3, 1fr); }
.align-center { align-items: center; }

.section {
    padding: 2rem 0;
    position: relative;
}

/* Buttons & CTA */
.btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    gap: 0.5rem;
    padding: 0.85rem 1.75rem;
    font-size: 0.95rem;
    font-weight: 700;
    border-radius: 50px;
    cursor: pointer;
    transition: var(--transition);
    border: none;
}

.btn-primary {
    background: var(--gold-gradient);
    color: var(--text-dark);
    box-shadow: 0 4px 20px rgba(212, 175, 55, 0.3);
}

.btn-primary:hover {
    transform: translateY(-2px);
    box-shadow: 0 6px 25px rgba(212, 175, 55, 0.5);
}

.btn-secondary {
    background: rgba(255, 255, 255, 0.05);
    color: var(--text-primary);
    border: 1px solid var(--border-color);
}

.btn-secondary:hover {
    background: rgba(212, 175, 55, 0.1);
    border-color: var(--gold-primary);
}

.btn-outline {
    background: transparent;
    color: var(--gold-primary);
    border: 1px solid var(--gold-primary);
}

.btn-outline:hover {
    background: var(--gold-primary);
    color: var(--text-dark);
}

.btn-large {
    padding: 1.1rem 2.25rem;
    font-size: 1.05rem;
}

.btn-card {
    background: rgba(255, 255, 255, 0.05);
    color: var(--gold-primary);
    width: 100%;
    margin-top: 1rem;
    border: 1px solid var(--border-light);
}

.btn-card:hover {
    background: var(--gold-primary);
    color: var(--text-dark);
}

/* Navbar */
.navbar {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    z-index: 1000;
    padding: 1rem 0;
    background: rgba(10, 12, 16, 0.85);
    backdrop-filter: blur(12px);
    border-bottom: 1px solid var(--border-light);
    transition: var(--transition);
}

.nav-container {
    display: flex;
    align-items: center;
    justify-content: space-between;
}

.nav-logo {
    height: 48px;
    width: auto;
    object-fit: contain;
}

.nav-list {
    display: flex;
    gap: 2rem;
}

.nav-link {
    font-size: 0.9rem;
    font-weight: 500;
    color: var(--text-secondary);
    position: relative;
    padding: 0.3rem 0;
}

.nav-link::after {
    content: '';
    position: absolute;
    bottom: 0;
    left: 50%;
    width: 0;
    height: 2px;
    background: var(--gold-gradient);
    transition: width 0.3s ease, left 0.3s ease;
    border-radius: 2px;
}

.nav-link:hover {
    color: var(--gold-primary);
}

.nav-link:hover::after {
    width: 100%;
    left: 0;
}

.hamburger {
    display: none;
    background: none;
    border: none;
    cursor: pointer;
    flex-direction: column;
    gap: 5px;
}

.hamburger .bar {
    width: 25px;
    height: 3px;
    background-color: var(--text-primary);
    border-radius: 2px;
    transition: var(--transition);
}

/* Hero Section */
.hero {
    padding: 11rem 0 6rem 0;
    background: linear-gradient(120deg, rgba(10, 12, 16, 0.80) 100%, rgba(10, 12, 16, 0.95) 100%), 
                url('../images/img3.jpg') center/cover no-repeat;
    position: relative;
    text-align: center;
}

.hero-container {
    max-width: 900px;
}

.hero-badge {
    display: inline-flex;
    align-items: center;
    gap: 0.5rem;
    padding: 0.4rem 1.2rem;
    background: rgba(212, 175, 55, 0.1);
    border: 1px solid var(--border-color);
    border-radius: 30px;
    font-size: 0.85rem;
    color: var(--gold-primary);
    margin-bottom: 1.5rem;
}

.hero-title {
    font-size: 3.5rem;
    font-weight: 800;
    line-height: 1.15;
    margin-bottom: 1.5rem;
}

.hero-subtitle {
    font-size: 0.95rem;
    letter-spacing: 2px;
    color: var(--gold-primary);
    font-weight: 700;
    margin-bottom: 1rem;
}

.hero-description {
    font-size: 1.2rem;
    color: var(--text-secondary);
    margin-bottom: 2.5rem;
}

.hero-actions {
    display: flex;
    gap: 1rem;
    justify-content: center;
}

/* About Section */
.about-section {
    background: #0d1017;
}

.lead-text {
    font-size: 1.2rem;
    color: var(--text-primary);
    margin-bottom: 1rem;
}

.feature-list {
    margin-top: 2rem;
    display: flex;
    flex-direction: column;
    gap: 1.5rem;
}

.feature-item {
    display: flex;
    gap: 1rem;
    align-items: flex-start;
}

.feature-icon {
    font-size: 1.5rem;
    color: var(--gold-primary);
    background: rgba(212, 175, 55, 0.1);
    padding: 0.8rem;
    border-radius: 12px;
}

.glass-image-card {
    position: relative;
    border-radius: 20px;
    overflow: hidden;
    border: 1px solid var(--border-color);
}

.about-feature-img {
    width: 100%;
    height: 380px;
    object-fit: cover;
}

.glass-card-caption {
    position: absolute;
    bottom: 0;
    left: 0;
    right: 0;
    background: rgba(18, 22, 32, 0.88);
    backdrop-filter: blur(8px);
    padding: 1.25rem;
    border-top: 1px solid var(--border-light);
}

.quote {
    font-style: italic;
    color: var(--text-secondary);
    margin: 0.5rem 0;
}

.location-tag {
    font-size: 0.85rem;
    color: var(--gold-primary);
}

/* Pillars Section */
.pillar-card {
    background: var(--bg-card);
    border: 1px solid var(--border-light);
    border-radius: 16px;
    padding: 2rem;
    transition: var(--transition);
}

.pillar-card:hover {
    transform: translateY(-5px);
    border-color: var(--gold-primary);
    background: var(--bg-card-hover);
}

.pillar-icon {
    font-size: 2rem;
    color: var(--gold-primary);
    margin-bottom: 1rem;
}

.pillar-card h3 {
    margin-bottom: 0.75rem;
    font-size: 1.25rem;
}

.pillar-card p {
    color: var(--text-secondary);
    font-size: 0.95rem;
}

.wide-card {
    grid-column: span 3;
}

/* Healthspan Section */
.healthspan-section {
    background: linear-gradient(180deg, #0d1017 0%, #0a0c10 100%);
}

.comparison-box {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 1.5rem;
    margin-top: 3rem;
}

.comp-col {
    padding: 2rem;
    border-radius: 16px;
}

.old-way {
    background: rgba(255, 255, 255, 0.02);
    border: 1px solid rgba(255, 255, 255, 0.05);
}

.nexcell-way {
    background: rgba(212, 175, 55, 0.05);
    border: 1px solid var(--border-color);
}

.comp-col h4 {
    margin-bottom: 1.5rem;
    font-size: 1.2rem;
}

.comp-col ul li {
    margin-bottom: 0.75rem;
    display: flex;
    align-items: center;
    gap: 0.75rem;
    color: var(--text-secondary);
}

.old-way li i { color: #e53e3e; }
.nexcell-way li i { color: var(--gold-primary); }

/* Cellular Systems */
.system-box {
    padding: 2rem;
    background: var(--bg-card);
    border-radius: 16px;
    border: 1px solid var(--border-light);
}

.system-icon {
    font-size: 2.5rem;
    color: var(--gold-primary);
    margin-bottom: 1rem;
}

/* Framework Timeline */
.timeline {
    display: flex;
    flex-direction: column;
    gap: 1.5rem;
    margin-top: 3rem;
    max-width: 800px;
    margin-left: auto;
    margin-right: auto;
}

.timeline-step {
    display: flex;
    align-items: center;
    gap: 2rem;
    background: var(--bg-card);
    border: 1px solid var(--border-light);
    padding: 1.5rem 2rem;
    border-radius: 16px;
    transition: var(--transition);
}

.timeline-step:hover {
    border-color: var(--gold-primary);
}

.step-number {
    font-size: 2rem;
    font-weight: 800;
    color: var(--gold-primary);
    background: rgba(212, 175, 55, 0.1);
    width: 60px;
    height: 60px;
    display: flex;
    align-items: center;
    justify-content: center;
    border-radius: 50%;
    flex-shrink: 0;
}

/* Products Section & Tabs */
.category-tabs {
    display: flex;
    justify-content: center;
    gap: 1rem;
    margin-top: 3rem;
    margin-bottom: 3rem;
    flex-wrap: wrap;
}

.tab-btn {
    background: rgba(255, 255, 255, 0.03);
    border: 1px solid var(--border-light);
    color: var(--text-secondary);
    padding: 0.6rem 1.4rem;
    border-radius: 30px;
    cursor: pointer;
    font-weight: 600;
    transition: var(--transition);
}

.tab-btn.active, .tab-btn:hover {
    background: var(--gold-primary);
    color: var(--text-dark);
    border-color: var(--gold-primary);
}

.product-card {
    background: var(--bg-card);
    border: 1px solid var(--border-light);
    border-radius: 20px;
    padding: 0;
    display: flex;
    flex-direction: column;
    justify-content: space-between;
    transition: var(--transition);
    position: relative;
    overflow: hidden;
}

.product-card:hover {
    border-color: var(--gold-primary);
    transform: translateY(-5px);
}

.highlight-card {
    border: 1px solid var(--gold-primary);
    background: radial-gradient(circle at 50% 0%, rgba(212, 175, 55, 0.1) 0%, var(--bg-card) 100%);
}

.product-thumb {
    width: 100%;
    height: 190px;
    background: #EEEFE5;
    display: flex;
    align-items: center;
    justify-content: center;
}

.product-thumb img {
    width: 100%;
    height: 100%;
    object-fit: cover;
}

.product-body {
    padding: 1.5rem;
    display: flex;
    flex-direction: column;
    flex-grow: 1;
    justify-content: space-between;
}

.brand-badge {
    align-self: flex-start;
    font-size: 0.75rem;
    text-transform: uppercase;
    font-weight: 700;
    letter-spacing: 1px;
    padding: 0.25rem 0.75rem;
    background: rgba(255, 255, 255, 0.05);
    border-radius: 20px;
    margin-bottom: 1rem;
    color: var(--text-secondary);
}

.badge-gold {
    background: rgba(212, 175, 55, 0.2);
    color: var(--gold-primary);
}

.product-category-tag {
    font-size: 0.85rem;
    color: var(--gold-primary);
    margin-bottom: 1rem;
    display: block;
    font-weight: 600;
}

.product-features {
    margin: 1.5rem 0;
}

.product-features li {
    font-size: 0.85rem;
    color: var(--text-secondary);
    margin-bottom: 0.5rem;
}

.brand-strip {
    margin-top: 4rem;
    text-align: center;
}

.brand-strip p {
    color: var(--text-secondary);
    font-size: 0.9rem;
    margin-bottom: 1.5rem;
}

.brand-logos {
    display: flex;
    justify-content: center;
    gap: 3rem;
    flex-wrap: wrap;
    font-weight: 800;
    letter-spacing: 2px;
    color: rgba(255, 255, 255, 0.3);
}

/* Credentials */
.cred-card {
    background: var(--bg-card);
    border: 1px solid var(--border-light);
    border-radius: 16px;
    padding: 2rem;
    text-align: center;
}

.cred-icon {
    font-size: 2.5rem;
    color: var(--gold-primary);
    margin-bottom: 1rem;
}

/* Articles */
.article-card {
    background: var(--bg-card);
    border: 1px solid var(--border-light);
    border-radius: 16px;
    padding: 0;
    overflow: hidden;
}

.article-img {
    width: 100%;
    height: 190px;
    object-fit: cover;
}

.article-content {
    padding: 1.5rem;
}

.article-category {
    color: var(--gold-primary);
    font-size: 0.8rem;
    text-transform: uppercase;
    font-weight: 700;
    margin-bottom: 0.5rem;
}

/* CTA & Footer */
.cta-card {
    background: radial-gradient(circle at 50% 50%, rgba(212, 175, 55, 0.15) 0%, rgba(18, 22, 32, 1) 100%);
    border: 1px solid var(--border-color);
    border-radius: 24px;
    padding: 4rem 2rem;
    text-align: center;
}

.cta-card h2 {
    font-size: 2.25rem;
    margin-bottom: 1rem;
}

.cta-actions {
    margin: 2rem 0 1rem 0;
}

.contact-note {
    font-size: 0.85rem;
    color: var(--text-secondary);
}

.footer {
    background: #06080a;
    padding: 4rem 0 2rem 0;
    border-top: 1px solid var(--border-light);
}

.footer-container {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 3rem;
}

.footer-logo {
    height: 40px;
    margin-bottom: 1rem;
}

.copyright {
    margin-top: 1rem;
    font-size: 0.85rem;
    color: var(--text-secondary);
}

.footer-info h4 {
    color: var(--gold-primary);
    margin-bottom: 1rem;
}

.footer-info p {
    color: var(--text-secondary);
    font-size: 0.9rem;
    margin-bottom: 0.5rem;
}

.disclaimer {
    font-size: 0.75rem !important;
    opacity: 0.5;
    margin-top: 1.5rem;
}

/* Floating WhatsApp Button */
.whatsapp-float {
    position: fixed;
    width: 60px;
    height: 60px;
    bottom: 30px;
    right: 30px;
    background-color: #25d366;
    color: #ffffff;
    border-radius: 50px;
    font-size: 32px;
    box-shadow: 0px 4px 15px rgba(0, 0, 0, 0.4);
    z-index: 1000;
    display: flex;
    align-items: center;
    justify-content: center;
    transition: var(--transition);
}

.whatsapp-float:hover {
    background-color: #20ba5a;
    color: #ffffff;
    transform: scale(1.1);
    box-shadow: 0px 6px 20px rgba(37, 211, 102, 0.5);
}

/* Scroll Animation Classes */
.animate-on-scroll {
    opacity: 0;
    transform: translateY(30px);
    transition: opacity 0.6s ease-out, transform 0.6s ease-out;
}

.animate-on-scroll.is-visible {
    opacity: 1;
    transform: translateY(0);
}

/* Media Queries */
@media (max-width: 992px) {
    .grid-3-col, .grid-2-col { grid-template-columns: 1fr; }
    .wide-card { grid-column: span 1; }
    .hero-title { font-size: 2.75rem; }
    .comparison-box { grid-template-columns: 1fr; }
    .footer-container { grid-template-columns: 1fr; }
}

@media (max-width: 768px) {
    .hamburger { display: flex; }
    .nav-cta-desktop { display: none; }

    .nav-menu {
        position: fixed;
        top: 70px;
        left: -100%;
        width: 100%;
        height: calc(100vh - 70px);
        background: var(--bg-main);
        flex-direction: column;
        justify-content: flex-start;
        padding: 3rem 2rem;
        transition: var(--transition);
        border-top: 1px solid var(--border-light);
    }

    .nav-menu.active { left: 0; }

    .nav-list {
        flex-direction: column;
        gap: 1.5rem;
        align-items: center;
        margin-bottom: 2rem;
    }

    .nav-link { font-size: 1.2rem; }

    .hero { padding: 7rem 0 6rem 0; }
    .hero-title { font-size: 2.25rem; }
    .hero-actions { flex-direction: column; }

    .hamburger.active .bar:nth-child(2) { opacity: 0; }
    .hamburger.active .bar:nth-child(1) { transform: translateY(8px) rotate(45deg); }
    .hamburger.active .bar:nth-child(3) { transform: translateY(-8px) rotate(-45deg); }

    .whatsapp-float {
        width: 50px;
        height: 50px;
        bottom: 20px;
        right: 20px;
        font-size: 26px;
    }
}

/* ==========================================================================
   Efectos y Animaciones de Scroll (Versión Suave / Lenta)
   ========================================================================== */

/* Fade-Up estándar */
.animate-fade-up {
    opacity: 0;
    transform: translateY(35px);
    transition: opacity 1.1s cubic-bezier(0.25, 1, 0.5, 1), transform 1.1s cubic-bezier(0.25, 1, 0.5, 1);
}

/* Fade-In con Zoom suave */
.animate-zoom-in {
    opacity: 0;
    transform: scale(0.92);
    transition: opacity 1.2s cubic-bezier(0.25, 1, 0.5, 1), transform 1.2s cubic-bezier(0.25, 1, 0.5, 1);
}

/* Entradas laterales alternadas */
.animate-fade-left {
    opacity: 0;
    transform: translateX(-45px);
    transition: opacity 1.1s cubic-bezier(0.25, 1, 0.5, 1), transform 1.1s cubic-bezier(0.25, 1, 0.5, 1);
}

.animate-fade-right {
    opacity: 0;
    transform: translateX(45px);
    transition: opacity 1.1s cubic-bezier(0.25, 1, 0.5, 1), transform 1.1s cubic-bezier(0.25, 1, 0.5, 1);
}

/* Estado visible desencadenado por JS */
.is-visible {
    opacity: 1 !important;
    transform: translate(0) scale(1) !important;
}

/* Developer Credit Link */
.developer-credit {
    font-size: 0.8rem;
    color: #94a3b8;
    margin-top: 0.5rem;
}

.developer-credit a {
    color: var(--gold-primary);
    font-weight: 600;
    text-underline-offset: 3px;
    transition: var(--transition);
}

.developer-credit a:hover {
    color: #d4af37;
    text-decoration: none;
    text-decoration: underline;
}