:root {
    --accent: #f0141e; /* Stal Vibrant Red */
    --bg-light: #f4f4f4;
    --sidebar-width: 260px;
    --font-main: 'Inter', sans-serif;
    --font-head: 'Montserrat', sans-serif;
}

* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

body {
    font-family: var(--font-main);
    background-color: var(--bg-light);
    color: #333;
}

/* SIDEBAR LAYOUT */
.sidebar {
    width: var(--sidebar-width);
    height: 100vh;
    position: fixed;
    top: 0;
    left: 0;
    background: #fff;
    border-right: 1px solid #eee;
    display: flex;
    flex-direction: column;
    z-index: 1000;
}

.logo-container {
    padding: 40px;
    text-align: center;
}

.logo-box {
    background: var(--accent);
    color: #fff;
    width: 60px;
    height: 60px;
    margin: 0 auto;
    display: flex;
    align-items: center;
    justify-content: center;
    font-family: var(--font-head);
    font-weight: 800;
    font-size: 20px;
    line-height: 1;
}

.side-nav {
    flex: 1;
    padding: 40px 0;
}

.side-nav ul li {
    list-style: none;
}

.side-nav ul li a {
    text-decoration: none;
    padding: 12px 40px;
    font-size: 14px;
    font-weight: 400;
    letter-spacing: 0.5px;
    text-transform: capitalize;
    color: #444; /* Gris oscuro solicitado */
    display: flex;
    justify-content: space-between;
    align-items: center;
    transition: 0.3s;
}

.side-nav ul li a i {
    font-size: 12px;
    color: #bbb;
    transition: 0.3s;
}

.side-nav ul li a:hover, .side-nav ul li.active a {
    color: var(--accent);
}

.side-nav ul li a:hover i, .side-nav ul li.active a i {
    color: var(--accent);
}

.side-footer {
    padding: 40px;
}

.social-links {
    display: flex;
    gap: 15px;
    justify-content: center;
}

.social-links i {
    font-size: 18px;
    color: #ccc;
    transition: 0.3s;
}

.social-links i:hover {
    color: var(--accent);
}

/* MAIN CONTENT */
.main-content {
    margin-left: var(--sidebar-width);
    min-height: 100vh;
}

/* Hero Section */
.hero-section {
    position: relative;
}

.hero-image-container {
    height: 80vh;
    overflow: hidden;
    position: relative;
}

.hero-image-container img {
    width: 100%;
    height: 100%;
    object-fit: cover;
}

.hero-text-overlay {
    position: absolute;
    top: 50%;
    left: 100px;
    transform: translateY(-50%);
    color: #ededed;
    z-index: 10;
}

.hero-title {
    font-family: var(--font-head);
    font-size: 64px;
    line-height: 1.1;
    font-weight: 500;
    margin-bottom: 30px;
}

.btn-stal {
    display: inline-block;
    background: var(--accent);
    color: #fff;
    padding: 15px 40px;
    font-weight: 700;
    font-size: 13px;
    letter-spacing: 2px;
    text-transform: uppercase;
    text-decoration: none;
}

.btn-stal .arrow {
    margin-left: 10px;
}

/* Overlapping Grid */
.feature-grid {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    width: 90%;
    margin: -100px auto 0;
    position: relative;
    z-index: 10;
    background: #fff;
    box-shadow: 0 30px 60px rgba(0,0,0,0.05);
}

.feature-card {
    padding: 60px 40px;
    border-right: 1px solid #f0f0f0;
    text-align: left;
}

.f-icon {
    font-size: 40px;
    color: var(--accent);
    margin-bottom: 25px;
}

.feature-card h3 {
    font-family: var(--font-head);
    font-size: 18px;
    margin-bottom: 15px;
    text-transform: uppercase;
}

.feature-card p {
    font-size: 14px;
    color: #888;
    line-height: 1.6;
}

/* Statistics */
.stats-section {
    padding: 120px 0;
    background: var(--bg-light); /* Gris suave */
}

.stats-container {
    display: flex;
    align-items: center;
    width: 90%;
    margin: 0 auto;
}

.stats-image {
    width: 60%;
    position: relative;
    z-index: 1;
}

.stats-image img {
    width: 100%;
    height: 600px;
    object-fit: cover;
    display: block;
}

.stats-box {
    width: 40%;
    background: #fff;
    padding: 60px 50px;
    margin-left: -80px;
    position: relative;
    z-index: 2;
    box-shadow: 0 30px 60px rgba(0,0,0,0.06);
}

.section-title {
    font-family: var(--font-head);
    font-size: 32px;
    line-height: 1.1;
    font-weight: 300;
    margin-bottom: 20px;
    text-transform: uppercase;
}

.section-desc {
    color: #888;
    margin-bottom: 30px;
}

.stats-list {
    margin-bottom: 25px;
}

.stats-list li {
    list-style: none;
    font-size: 14px;
    color: #444;
    margin-bottom: 6px;
    font-weight: 400;
    display: flex;
    align-items: center;
    gap: 10px;
    line-height: 1.3;
}

.stats-list li i {
    color: var(--accent);
    font-size: 16px;
    font-weight: bold;
}

.stats-footer p {
    font-family: var(--font-head);
    font-size: 18px;
    color: var(--accent);
    margin-bottom: 5px;
    text-transform: uppercase;
    font-weight: 300;
}

/* El Problema (Brief History Style) */
.history-section {
    padding: 120px 0;
    background: var(--bg-light); /* Gris suave aplicado */
    border-top: 1px solid #eee;
}

.history-container {
    width: 90%;
    max-width: 1300px;
    margin: 0 auto;
    display: grid;
    grid-template-columns: 50px 1.5fr 50px 1.5fr; /* Doble bloque: [Título] [Contenido] [Título] [Contenido] */
    gap: 20px;
}

.h-vertical-col {
    position: relative;
    display: flex;
    justify-content: flex-end; /* Alinea al borde derecho de su pequeña columna */
}

.h-vertical-title {
    font-family: var(--font-head);
    font-size: 14px;
    font-weight: 700;
    color: var(--accent);
    letter-spacing: 1px; /* Reducción drástica del espaciado entre letras */
    text-transform: uppercase;
    writing-mode: vertical-rl;
    transform: rotate(180deg);
    position: absolute;
    top: 10px;
    right: 0; /* Lo pega al límite derecho de su contenedor */
    white-space: nowrap;
}

.h-subtitle {
    font-family: var(--font-head);
    font-size: 38px;
    font-weight: 300;
    margin-bottom: 30px;
    color: var(--dark);
    line-height: 1.2;
}

.h-lead {
    font-size: 18px;
    line-height: 1.6;
    color: #333;
    margin-bottom: 25px;
}

.h-text {
    font-size: 15px;
    color: #666;
    line-height: 1.8;
    margin-bottom: 25px;
}

.h-conclusion {
    font-family: var(--font-head);
    font-size: 18px;
    font-weight: 300;
    color: var(--accent);
    margin-top: 30px;
    letter-spacing: 1px;
}

/* Architecture Section */
.arch-section {
    padding: 120px 0;
    background: var(--bg-light);
}

.arch-header {
    text-align: center;
    margin-bottom: 70px;
}

.arch-title {
    font-family: var(--font-head);
    font-size: 14px;
    font-weight: 700;
    color: var(--accent);
    letter-spacing: 2px;
    text-transform: uppercase;
    margin-bottom: 15px;
}

.arch-subtitle {
    font-family: var(--font-head);
    font-size: 22px;
    font-weight: 300;
    color: var(--dark);
    line-height: 1.1;
    text-transform: uppercase;
}

.arch-grid {
    width: 90%;
    max-width: 1200px;
    margin: 0 auto;
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 40px;
}

/* Sectors Cards (Image Based) */
.sector-card {
    background: #fff;
    overflow: hidden;
    transition: 0.3s;
}

.sector-img {
    width: 100%;
    height: 500px;
    overflow: hidden;
    position: relative;
}

.sector-img img {
    width: 100%;
    height: 100%;
    object-fit: cover;
    transition: transform 0.6s ease;
}

.sector-card:hover .sector-img img {
    transform: scale(1.08); /* Suave zoom al pasar el mouse (Stal style) */
}

.sector-content {
    padding: 35px 0;
}

.sector-text-row {
    display: flex;
    gap: 15px;
    align-items: flex-start;
}

.sector-number {
    font-family: var(--font-head);
    font-size: 13px;
    font-weight: 700;
    color: var(--accent);
    letter-spacing: 1px;
    writing-mode: vertical-rl;
    transform: rotate(180deg);
    white-space: nowrap;
    margin-top: 5px;
}

.sector-body {
    flex: 1;
}

.sector-title {
    font-family: var(--font-head);
    font-size: 22px;
    font-weight: 700;
    margin-bottom: 10px;
    text-transform: none; /* Allows mixed case like Minería */
    color: var(--dark);
    letter-spacing: 0.5px;
}

.sector-desc {
    font-size: 15px;
    color: #666;
    line-height: 1.6;
    font-weight: 400;
}

/* Pricing Section */
.pricing-section {
    padding: 100px 0;
    background: #fff;
}

.pricing-grid {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    width: 90%;
    margin: 0 auto;
    gap: 30px;
}

.price-card {
    background: #f9f9f9;
    padding: 80px 50px;
    text-align: center;
    border: 1px solid #f0f0f0;
}

.price-card.highlight {
    background: #fff;
    box-shadow: 0 20px 50px rgba(0,0,0,0.05);
    border: none;
}

.p-tag {
    font-size: 11px;
    letter-spacing: 3px;
    font-weight: 700;
    color: var(--accent);
    display: block;
    margin-bottom: 30px;
}

.p-amount {
    font-family: var(--font-head);
    font-size: 80px;
    font-weight: 800;
    line-height: 1;
    margin-bottom: 10px;
}

.p-amount span {
    font-size: 24px;
    vertical-align: top;
    margin-left: 5px;
}

.p-cycle {
    font-size: 13px;
    color: #999;
    margin-bottom: 40px;
}

.p-features {
    margin-bottom: 50px;
}

.p-features li {
    list-style: none;
    font-size: 12px;
    font-weight: 600;
    color: #333;
    margin-bottom: 15px;
    letter-spacing: 1px;
}

.btn-purchase {
    display: inline-block;
    width: 100%;
    padding: 20px;
    background: var(--accent);
    color: #fff;
    font-weight: 700;
    font-size: 13px;
    text-transform: uppercase;
    text-decoration: none;
    letter-spacing: 2px;
}

/* Floating Controls */
.floating-controls {
    position: fixed;
    right: 30px;
    top: 50%;
    transform: translateY(-50%);
    display: flex;
    flex-direction: column;
    gap: 10px;
    z-index: 2000;
}

.float-btn {
    width: 50px;
    height: 50px;
    border: none;
    cursor: pointer;
    box-shadow: 0 10px 20px rgba(0,0,0,0.1);
    font-size: 20px;
    display: flex;
    align-items: center;
    justify-content: center;
}

.float-btn.red { background: var(--accent); color: #fff; }
.float-btn.white { background: #fff; color: #111; }

/* Responsive */
@media (max-width: 1200px) {
    .feature-grid { grid-template-columns: repeat(2, 1fr); }
    .hero-title { font-size: 48px; }
}

@media (max-width: 768px) {
    .sidebar { display: none; }
    .main-content { margin-left: 0; }
    .feature-grid { grid-template-columns: 1fr; }
    .stats-container { flex-direction: column; }
    .stats-image, .stats-box { width: 100%; margin-left: 0; }
    .stats-box { margin-top: -50px; padding: 40px 30px; }
    .history-container { grid-template-columns: 1fr; gap: 40px; }
    .arch-grid { grid-template-columns: 1fr; }
    .pricing-grid { grid-template-columns: 1fr; }
}

/* INTERNAL PAGE HEADER (Stal Style) */
.internal-header {
    height: 50vh;
    min-height: 400px;
    background-color: #1b1b1b;
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    text-align: center;
    color: #fff;
    position: relative;
    overflow: hidden;
}

.internal-title {
    font-family: var(--font-head);
    font-size: 80px;
    font-weight: 800;
    line-height: 1;
    text-transform: capitalize;
    margin-bottom: 20px;
    letter-spacing: -2px;
}

.breadcrumbs {
    font-family: var(--font-main);
    font-size: 13px;
    color: #a0a0a0;
    letter-spacing: 2px;
    text-transform: uppercase;
    font-weight: 600;
}

.breadcrumbs a {
    color: #fff;
    text-decoration: none;
    transition: 0.3s;
}

.breadcrumbs a:hover {
    color: var(--accent);
}

.breadcrumbs span {
    margin: 0 10px;
    color: #666;
}


/* STAL ACCORDION (Plataforma Architecture) */
.stal-accordion-item {
    border-bottom: 1px solid #ddd;
}
.stal-accordion-item:first-child {
    border-top: 1px solid #ddd;
}
.stal-accordion-header {
    padding: 30px 0;
    cursor: pointer;
    display: flex;
    align-items: center;
    transition: 0.3s;
}
.stal-accordion-header:hover .acc-title {
    color: var(--accent);
}
.acc-num {
    font-family: var(--font-head);
    font-size: 18px;
    font-weight: 500;
    color: var(--accent);
    margin-right: 25px;
}
.acc-title {
    font-family: var(--font-head);
    font-size: 22px;
    font-weight: 500;
    color: #1b1b1b;
    transition: 0.3s;
    letter-spacing: -0.5px;
}
.stal-accordion-content {
    max-height: 0;
    overflow: hidden;
    transition: max-height 0.4s ease-out;
}
.stal-accordion-item.active .stal-accordion-content {
    max-height: 800px;
    transition: max-height 0.4s ease-in;
}
.stal-accordion-item.active .acc-title {
    color: var(--accent);
}
.acc-inner {
    padding-bottom: 40px;
    padding-left: 45px;
}
.acc-inner p {
    font-size: 16px;
    color: #666;
    line-height: 1.7;
    margin-bottom: 15px;
}
.acc-inner ul {
    list-style: none;
    padding: 0;
    margin-bottom: 25px;
}
.acc-inner ul li {
    font-size: 16px;
    color: #444;
    margin-bottom: 10px;
    position: relative;
    padding-left: 18px;
}
.acc-inner ul li::before {
    content: '•';
    color: var(--accent);
    position: absolute;
    left: 0;
    font-weight: bold;
}
.acc-highlight {
    font-family: var(--font-head);
    font-size: 16px !important;
    font-weight: 700;
    color: #1b1b1b !important;
    margin-top: 25px;
    border-left: 3px solid var(--accent);
    padding-left: 15px;
}