/* ========================================
   VARIABLES CSS
   ======================================== */
:root {
    /* Colores */
    --color-white: #FFFFFF;
    --color-off-white: #F8F9FA;
    --color-primary: #1A3A52;
    --color-secondary: #2C5F7C;
    --color-accent: #C9A961;
    --color-text: #2D3748;
    --color-text-light: #718096;
    --color-border: #E2E8F0;
    --color-bg-section: #FAFBFC;

    /* Tipografía */
    --font-primary: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', sans-serif;
    --font-display: 'Merriweather', Georgia, serif;

    /* Spacing */
    --spacing-xs: 0.5rem;
    --spacing-sm: 1rem;
    --spacing-md: 1.5rem;
    --spacing-lg: 2rem;
    --spacing-xl: 3rem;
    --spacing-2xl: 4rem;
    --spacing-3xl: 6rem;

    /* Container */
    --container-max: 1200px;
    --container-padding: 2rem;

    /* Border radius */
    --radius-sm: 4px;
    --radius-md: 8px;
    --radius-lg: 12px;

    /* Shadows */
    --shadow-sm: 0 1px 3px rgba(0, 0, 0, 0.08);
    --shadow-md: 0 4px 12px rgba(0, 0, 0, 0.1);
    --shadow-lg: 0 8px 24px rgba(0, 0, 0, 0.12);

    /* Transitions */
    --transition: all 0.3s ease;
}

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

html {
    scroll-behavior: smooth;
}

body {
    font-family: var(--font-primary);
    font-size: 16px;
    line-height: 1.7;
    color: var(--color-text);
    background: var(--color-white);
    -webkit-font-smoothing: antialiased;
    -moz-osx-font-smoothing: grayscale;
}

/* ========================================
   TIPOGRAFÍA
   ======================================== */
h1, h2, h3, h4, h5, h6 {
    font-weight: 700;
    line-height: 1.2;
    color: var(--color-primary);
}

h1 {
    font-family: var(--font-display);
    font-size: clamp(2.5rem, 5vw, 3.5rem);
    font-weight: 900;
}

h2 {
    font-family: var(--font-display);
    font-size: clamp(2rem, 4vw, 2.75rem);
    font-weight: 700;
}

h3 {
    font-size: clamp(1.25rem, 2.5vw, 1.5rem);
}

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

a {
    color: inherit;
    text-decoration: none;
}

/* ========================================
   UTILIDADES
   ======================================== */
.container {
    max-width: var(--container-max);
    margin: 0 auto;
    padding: 0 var(--container-padding);
}

.section {
    padding: var(--spacing-3xl) 0;
}

.section-header {
    margin-bottom: var(--spacing-2xl);
}

.section-header.centered {
    text-align: center;
    max-width: 800px;
    margin-left: auto;
    margin-right: auto;
    margin-bottom: var(--spacing-2xl);
}

.section-title {
    margin-bottom: var(--spacing-md);
}

.section-intro {
    font-size: 1.125rem;
    color: var(--color-text-light);
    line-height: 1.8;
}

/* Animaciones de aparición */
.fade-in {
    opacity: 0;
    transform: translateY(30px);
    transition: opacity 0.6s ease, transform 0.6s ease;
}

.fade-in.visible {
    opacity: 1;
    transform: translateY(0);
}

/* ========================================
   HEADER
   ======================================== */
.header {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    background: var(--color-white);
    box-shadow: var(--shadow-sm);
    z-index: 1000;
    transition: var(--transition);
}

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

.header-content {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 1rem var(--container-padding);
}

.logo-text {
    font-family: var(--font-display);
    font-size: 1.75rem;
    font-weight: 900;
    color: var(--color-primary);
}

.logo-accent {
    color: var(--color-accent);
}

.nav {
    display: flex;
    align-items: center;
    gap: var(--spacing-lg);
}

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

.nav-link {
    font-size: 0.9375rem;
    font-weight: 500;
    color: var(--color-text);
    transition: var(--transition);
    position: relative;
}

.nav-link:hover,
.nav-link.active {
    color: var(--color-secondary);
}

.nav-link::after {
    content: '';
    position: absolute;
    bottom: -4px;
    left: 0;
    width: 0;
    height: 2px;
    background: var(--color-accent);
    transition: width 0.3s ease;
}

.nav-link:hover::after,
.nav-link.active::after {
    width: 100%;
}

.menu-toggle {
    display: none;
    flex-direction: column;
    gap: 5px;
    background: none;
    border: none;
    cursor: pointer;
    padding: 0.5rem;
}

.menu-toggle span {
    width: 25px;
    height: 2px;
    background: var(--color-primary);
    transition: var(--transition);
}

.menu-toggle.active span:nth-child(1) {
    transform: rotate(45deg) translate(7px, 7px);
}

.menu-toggle.active span:nth-child(2) {
    opacity: 0;
}

.menu-toggle.active span:nth-child(3) {
    transform: rotate(-45deg) translate(7px, -7px);
}

/* ========================================
   BOTONES
   ======================================== */
.btn {
    display: inline-block;
    padding: 0.875rem 2rem;
    font-size: 0.9375rem;
    font-weight: 600;
    border: none;
    border-radius: var(--radius-md);
    cursor: pointer;
    transition: var(--transition);
    text-align: center;
    white-space: nowrap;
}

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

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

.btn-secondary {
    background: transparent;
    color: var(--color-primary);
    border: 2px solid var(--color-primary);
}

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

.btn-large {
    padding: 1.125rem 2.5rem;
    font-size: 1rem;
}

.btn-full {
    width: 100%;
}

.btn-header {
    padding: 0.625rem 1.5rem;
    font-size: 0.875rem;
}

/* ========================================
   HERO SECTION
   ======================================== */
.hero {
    padding-top: calc(80px + var(--spacing-3xl));
    padding-bottom: var(--spacing-3xl);
    background: linear-gradient(135deg, #F8F9FA 0%, #FFFFFF 100%);
    position: relative;
    overflow: hidden;
}

.hero-content {
    max-width: 50%;
    position: relative;
    z-index: 2;
    padding-right: var(--spacing-xl);
}

.hero-title {
    margin-bottom: var(--spacing-md);
    line-height: 1.1;
}

.hero-subtitle {
    font-size: 1.25rem;
    line-height: 1.7;
    color: var(--color-text-light);
    margin-bottom: var(--spacing-xl);
}

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

.hero-image-container {
    position: absolute;
    top: 0;
    right: 0;
    width: 50%;
    height: 100%;
    z-index: 1;
}

.hero-image-placeholder {
    width: 100%;
    height: 100%;
    background: linear-gradient(135deg, rgba(26, 58, 82, 0.15) 0%, rgba(44, 95, 124, 0.25) 100%),
                url('../assets/images/hero-library.jpg') center/cover no-repeat;
    background-blend-mode: multiply;
}

/* ========================================
   PROBLEMA SECTION
   ======================================== */
.problema {
    background: var(--color-white);
}

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

.problema-card {
    padding: var(--spacing-xl);
    background: var(--color-off-white);
    border-radius: var(--radius-lg);
    transition: var(--transition);
}

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

.problema-icon {
    color: var(--color-secondary);
    margin-bottom: var(--spacing-md);
}

.problema-card-title {
    margin-bottom: var(--spacing-sm);
    color: var(--color-primary);
}

.problema-card-text {
    color: var(--color-text-light);
    line-height: 1.7;
    margin: 0;
}

/* ========================================
   QUÉ HACEMOS SECTION
   ======================================== */
.que-hacemos {
    background: var(--color-bg-section);
}

.que-hacemos-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(320px, 1fr));
    gap: var(--spacing-lg);
}

.feature-card {
    padding: var(--spacing-xl);
    background: var(--color-white);
    border-radius: var(--radius-lg);
    border-left: 4px solid var(--color-accent);
    transition: var(--transition);
}

.feature-card:hover {
    transform: translateX(8px);
    box-shadow: var(--shadow-md);
}

.feature-number {
    font-family: var(--font-display);
    font-size: 2.5rem;
    font-weight: 900;
    color: var(--color-accent);
    opacity: 0.3;
    line-height: 1;
    margin-bottom: var(--spacing-sm);
}

.feature-title {
    margin-bottom: var(--spacing-sm);
}

.feature-text {
    color: var(--color-text-light);
    margin: 0;
}

/* ========================================
   CÓMO TRABAJAMOS SECTION
   ======================================== */
.como-trabajamos {
    background: var(--color-white);
}

.metodologia {
    max-width: 900px;
    margin: 0 auto;
}

.metodologia-step {
    display: grid;
    grid-template-columns: 80px 1fr;
    gap: var(--spacing-lg);
    margin-bottom: var(--spacing-xl);
}

.metodologia-step:last-child {
    margin-bottom: 0;
}

.step-indicator {
    display: flex;
    flex-direction: column;
    align-items: center;
}

.step-circle {
    width: 60px;
    height: 60px;
    border-radius: 50%;
    background: var(--color-primary);
    color: var(--color-white);
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 1.5rem;
    font-weight: 700;
    flex-shrink: 0;
}

.step-line {
    width: 2px;
    flex: 1;
    background: var(--color-border);
    margin-top: var(--spacing-sm);
}

.metodologia-step:last-child .step-line {
    display: none;
}

.step-content {
    padding-top: 0.5rem;
}

.step-title {
    margin-bottom: var(--spacing-sm);
    color: var(--color-primary);
}

.step-text {
    color: var(--color-text-light);
    margin: 0;
}

/* ========================================
   SERVICIOS SECTION
   ======================================== */
.servicios {
    background: var(--color-bg-section);
}

.servicios-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(320px, 1fr));
    gap: var(--spacing-xl);
}

.servicio-card {
    padding: var(--spacing-xl);
    background: var(--color-white);
    border-radius: var(--radius-lg);
    box-shadow: var(--shadow-sm);
    transition: var(--transition);
}

.servicio-card:hover {
    transform: translateY(-8px);
    box-shadow: var(--shadow-lg);
}

.servicio-icon {
    width: 56px;
    height: 56px;
    background: var(--color-off-white);
    border-radius: var(--radius-md);
    display: flex;
    align-items: center;
    justify-content: center;
    margin-bottom: var(--spacing-md);
    color: var(--color-secondary);
}

.servicio-title {
    margin-bottom: var(--spacing-sm);
}

.servicio-text {
    color: var(--color-text-light);
    margin: 0;
}

/* ========================================
   BENEFICIOS SECTION
   ======================================== */
.beneficios {
    background: var(--color-white);
}

.beneficios-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: var(--spacing-xl);
    margin-bottom: var(--spacing-3xl);
}

.beneficio-item {
    display: flex;
    flex-direction: column;
    gap: var(--spacing-md);
}

.beneficio-icon-wrapper {
    width: 48px;
    height: 48px;
    color: var(--color-accent);
}

.beneficio-title {
    color: var(--color-primary);
    margin-bottom: var(--spacing-xs);
}

.beneficio-text {
    color: var(--color-text-light);
    margin: 0;
}

/* Clientes section */
.clientes-section {
    padding-top: var(--spacing-2xl);
    border-top: 1px solid var(--color-border);
}

.clientes-title {
    text-align: center;
    font-size: 1.5rem;
    color: var(--color-primary);
    margin-bottom: var(--spacing-xl);
}

.clientes-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: var(--spacing-md);
}

.cliente-item {
    padding: var(--spacing-md);
    background: var(--color-off-white);
    border-radius: var(--radius-md);
    text-align: center;
    font-weight: 500;
    color: var(--color-text);
}

/* ========================================
   NOSOTROS SECTION
   ======================================== */
.nosotros {
    background: linear-gradient(rgba(250, 251, 252, 0.97), rgba(250, 251, 252, 0.97)),
                url('../assets/images/university-hall.jpg') center/cover no-repeat fixed;
}

.nosotros-content {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: var(--spacing-3xl);
    align-items: start;
}

.nosotros-paragraph {
    font-size: 1.0625rem;
    line-height: 1.8;
    color: var(--color-text-light);
    margin-bottom: var(--spacing-md);
}

.nosotros-values {
    display: flex;
    flex-direction: column;
    gap: var(--spacing-xl);
}

.value-item {
    padding: var(--spacing-xl);
    background: var(--color-white);
    border-radius: var(--radius-lg);
    border-top: 3px solid var(--color-accent);
}

.value-title {
    color: var(--color-primary);
    margin-bottom: var(--spacing-sm);
}

.value-text {
    color: var(--color-text-light);
    margin: 0;
}

/* ========================================
   FAQ SECTION
   ======================================== */
.faq {
    background: var(--color-white);
}

.faq-container {
    max-width: 900px;
    margin: 0 auto;
}

.faq-item {
    border-bottom: 1px solid var(--color-border);
}

.faq-question {
    width: 100%;
    padding: var(--spacing-lg) 0;
    background: none;
    border: none;
    display: flex;
    justify-content: space-between;
    align-items: center;
    cursor: pointer;
    text-align: left;
    font-size: 1.125rem;
    font-weight: 600;
    color: var(--color-primary);
    transition: var(--transition);
}

.faq-question:hover {
    color: var(--color-secondary);
}

.faq-icon {
    flex-shrink: 0;
    transition: transform 0.3s ease;
    color: var(--color-accent);
}

.faq-item.active .faq-icon {
    transform: rotate(180deg);
}

.faq-answer {
    max-height: 0;
    overflow: hidden;
    transition: max-height 0.3s ease, padding 0.3s ease;
}

.faq-item.active .faq-answer {
    max-height: 500px;
    padding-bottom: var(--spacing-lg);
}

.faq-answer p {
    color: var(--color-text-light);
    line-height: 1.8;
    margin: 0;
}

/* ========================================
   CONTACTO SECTION
   ======================================== */
.contacto {
    background: linear-gradient(rgba(26, 58, 82, 0.92), rgba(26, 58, 82, 0.95)),
                url('../assets/images/books-education.jpg') center/cover no-repeat;
    color: var(--color-white);
}

.contacto .section-title {
    color: var(--color-white);
}

.contacto-content {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: var(--spacing-3xl);
    align-items: start;
}

.contacto-text {
    font-size: 1.125rem;
    line-height: 1.8;
    margin-bottom: var(--spacing-xl);
    color: rgba(255, 255, 255, 0.9);
}

.contacto-details {
    display: flex;
    flex-direction: column;
    gap: var(--spacing-md);
}

.contacto-detail-item {
    display: flex;
    align-items: center;
    gap: var(--spacing-sm);
    color: rgba(255, 255, 255, 0.9);
}

.contacto-detail-item svg {
    flex-shrink: 0;
}

/* Formulario */
.contacto-form {
    background: var(--color-white);
    padding: var(--spacing-xl);
    border-radius: var(--radius-lg);
}

.form-group {
    margin-bottom: var(--spacing-md);
}

.form-label {
    display: block;
    margin-bottom: var(--spacing-xs);
    font-weight: 500;
    color: var(--color-text);
}

.form-input,
.form-textarea {
    width: 100%;
    padding: 0.875rem;
    border: 1px solid var(--color-border);
    border-radius: var(--radius-md);
    font-family: var(--font-primary);
    font-size: 0.9375rem;
    transition: var(--transition);
}

.form-input:focus,
.form-textarea:focus {
    outline: none;
    border-color: var(--color-secondary);
    box-shadow: 0 0 0 3px rgba(44, 95, 124, 0.1);
}

.form-textarea {
    resize: vertical;
}

/* ========================================
   FOOTER
   ======================================== */
.footer {
    background: var(--color-primary);
    color: var(--color-white);
    padding: var(--spacing-3xl) 0 var(--spacing-lg);
}

.footer-content {
    display: grid;
    grid-template-columns: 2fr 1fr 1fr 1fr;
    gap: var(--spacing-xl);
    margin-bottom: var(--spacing-xl);
}

.footer-tagline {
    color: rgba(255, 255, 255, 0.8);
    margin-top: var(--spacing-sm);
    margin-bottom: 0;
}

.footer-links-title {
    font-size: 0.875rem;
    font-weight: 700;
    text-transform: uppercase;
    letter-spacing: 0.5px;
    margin-bottom: var(--spacing-md);
    color: var(--color-white);
}

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

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

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

.footer-links-list a:hover {
    color: var(--color-accent);
}

.footer-contact p {
    color: rgba(255, 255, 255, 0.8);
    margin-bottom: var(--spacing-xs);
}

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

.footer-bottom p {
    color: rgba(255, 255, 255, 0.6);
    font-size: 0.875rem;
    margin: 0;
}

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

/* Tablet */
@media (max-width: 992px) {
    :root {
        --container-padding: 1.5rem;
        --spacing-3xl: 4rem;
    }

    .nav {
        position: fixed;
        top: 73px;
        left: 0;
        width: 100%;
        background: var(--color-white);
        flex-direction: column;
        padding: var(--spacing-lg);
        box-shadow: var(--shadow-md);
        transform: translateX(-100%);
        transition: transform 0.3s ease;
    }

    .nav.active {
        transform: translateX(0);
    }

    .nav-list {
        flex-direction: column;
        gap: var(--spacing-sm);
        width: 100%;
    }

    .nav-list li {
        width: 100%;
    }

    .nav-link {
        display: block;
        padding: var(--spacing-sm);
    }

    .btn-header {
        width: 100%;
    }

    .menu-toggle {
        display: flex;
    }

    .hero-content {
        max-width: 100%;
        padding-right: 0;
    }

    .hero-image-container {
        display: none;
    }

    .contacto-content,
    .nosotros-content {
        grid-template-columns: 1fr;
        gap: var(--spacing-xl);
    }

    .footer-content {
        grid-template-columns: 1fr 1fr;
        gap: var(--spacing-xl);
    }

    .footer-brand {
        grid-column: 1 / -1;
    }
}

/* Mobile */
@media (max-width: 640px) {
    :root {
        --container-padding: 1rem;
        --spacing-xl: 2rem;
        --spacing-2xl: 3rem;
        --spacing-3xl: 3rem;
    }

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

    .hero {
        padding-top: calc(73px + var(--spacing-2xl));
    }

    .hero-cta {
        flex-direction: column;
    }

    .hero-cta .btn {
        width: 100%;
    }

    .problema-grid,
    .que-hacemos-grid,
    .servicios-grid,
    .beneficios-grid,
    .clientes-grid {
        grid-template-columns: 1fr;
    }

    .metodologia-step {
        grid-template-columns: 60px 1fr;
        gap: var(--spacing-md);
    }

    .step-circle {
        width: 50px;
        height: 50px;
        font-size: 1.25rem;
    }

    .footer-content {
        grid-template-columns: 1fr;
    }
}

/* Print */
@media print {
    .header,
    .menu-toggle,
    .footer {
        display: none;
    }
}