/* Reset y configuración base */
* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

html {
    scroll-behavior: smooth;
}

body {
    font-family: 'Roboto', sans-serif;
    line-height: 1.6;
    color: #44546A;
    background-color: #FFFFFF;
}

.container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 20px;
}

/* Header */
.header {
    background-color: #FFFFFF;
    box-shadow: 0 2px 10px rgba(68, 114, 196, 0.1);
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    z-index: 1000;
    transition: all 0.3s ease;
}

.header-content {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 1rem 0;
}

.logo {
    height: 60px;
    width: auto;
    transition: transform 0.3s ease;
}

.logo:hover {
    transform: scale(1.05);
}

.nav-list {
    display: flex;
    list-style: none;
    gap: 2rem;
}

.nav-link {
    text-decoration: none;
    color: #44546A;
    font-weight: 500;
    padding: 0.5rem 1rem;
    border-radius: 25px;
    transition: all 0.3s ease;
    position: relative;
}

.nav-link:hover {
    color: #4472C4;
    background-color: rgba(68, 114, 196, 0.1);
    transform: translateY(-2px);
}

/* Hero Section */
.hero {
    background: linear-gradient(135deg, #4472C4 0%, #5B9BD5 100%);
    color: white;
    padding: 120px 0 80px;
    margin-top: 80px;
    position: relative;
    overflow: hidden;
}

.hero::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background: url('data:image/svg+xml,<svg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 100 100"><defs><pattern id="grain" width="100" height="100" patternUnits="userSpaceOnUse"><circle cx="25" cy="25" r="1" fill="white" opacity="0.1"/><circle cx="75" cy="75" r="1" fill="white" opacity="0.1"/><circle cx="50" cy="10" r="1" fill="white" opacity="0.1"/><circle cx="10" cy="60" r="1" fill="white" opacity="0.1"/><circle cx="90" cy="40" r="1" fill="white" opacity="0.1"/></pattern></defs><rect width="100" height="100" fill="url(%23grain)"/></svg>');
    opacity: 0.3;
}

.hero-content {
    position: relative;
    z-index: 2;
    text-align: center;
    max-width: 900px;
    margin: 0 auto;
}

.hero-title {
    font-size: 3rem;
    font-weight: 700;
    margin-bottom: 2rem;
    line-height: 1.2;
    text-shadow: 0 2px 4px rgba(0, 0, 0, 0.1);
    animation: fadeInUp 1s ease-out;
}

.authors {
    background: rgba(255, 255, 255, 0.1);
    backdrop-filter: blur(10px);
    border-radius: 15px;
    padding: 1.5rem;
    margin: 2rem 0;
    animation: fadeInUp 1s ease-out 0.2s both;
}

.authors ul {
    list-style: none;
    margin-top: 1rem;
}

.authors li {
    margin: 0.5rem 0;
    font-size: 1.1rem;
}

.institution {
    animation: fadeInUp 1s ease-out 0.4s both;
}

.institution p {
    font-size: 1.2rem;
    margin: 0.5rem 0;
}

/* Table of Contents */
.table-of-contents {
    padding: 80px 0;
    background: linear-gradient(45deg, #f8f9fa 0%, #e9ecef 100%);
}

.section-title {
    font-size: 2.5rem;
    color: #4472C4;
    text-align: center;
    margin-bottom: 3rem;
    font-weight: 700;
    position: relative;
}

.section-title::after {
    content: '';
    position: absolute;
    bottom: -10px;
    left: 50%;
    transform: translateX(-50%);
    width: 80px;
    height: 4px;
    background: linear-gradient(90deg, #4472C4, #5B9BD5);
    border-radius: 2px;
}

.toc-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: 2rem;
    margin-top: 3rem;
}

.toc-item {
    background: white;
    border-radius: 15px;
    padding: 2rem;
    box-shadow: 0 5px 20px rgba(68, 114, 196, 0.1);
    transition: all 0.3s ease;
    cursor: pointer;
    border: 2px solid transparent;
    position: relative;
    overflow: hidden;
}

.toc-item::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 4px;
    background: linear-gradient(90deg, #4472C4, #5B9BD5);
    transform: scaleX(0);
    transition: transform 0.3s ease;
}

.toc-item:hover {
    transform: translateY(-5px);
    box-shadow: 0 10px 30px rgba(68, 114, 196, 0.2);
    border-color: #4472C4;
}

.toc-item:hover::before {
    transform: scaleX(1);
}

.toc-item h3 {
    color: #4472C4;
    font-size: 1.3rem;
    margin-bottom: 1rem;
    font-weight: 600;
}

.toc-item p {
    color: #44546A;
    font-size: 1rem;
    line-height: 1.5;
}

/* Content Sections */
.content-section {
    padding: 80px 0;
    border-bottom: 1px solid #E7E6E6;
    transition: all 0.5s ease;
}

.content-section:nth-child(even) {
    background-color: #f8f9fa;
}

.content-text {
    max-width: 800px;
    margin: 0 auto;
    font-size: 1.1rem;
    line-height: 1.8;
}

.content-text p {
    margin-bottom: 1.5rem;
    text-align: justify;
}

.content-text h3 {
    color: #4472C4;
    font-size: 1.5rem;
    margin: 2rem 0 1rem;
    font-weight: 600;
}

.content-text ul {
    margin: 1rem 0 1.5rem 2rem;
}

.content-text li {
    margin: 0.5rem 0;
}

/* Highlight Boxes */
.highlight-box {
    background: linear-gradient(135deg, #4472C4 0%, #5B9BD5 100%);
    color: white;
    padding: 2rem;
    border-radius: 15px;
    margin: 2rem 0;
    box-shadow: 0 5px 20px rgba(68, 114, 196, 0.3);
}

.highlight-box h3 {
    color: white !important;
    margin-bottom: 1rem;
}

.highlight-box p {
    font-size: 1.2rem;
    font-style: italic;
    text-align: center;
}

.objective-box {
    background: white;
    border: 2px solid #4472C4;
    border-radius: 15px;
    padding: 2rem;
    margin: 2rem 0;
    box-shadow: 0 5px 15px rgba(68, 114, 196, 0.1);
}

.objective-box h3 {
    color: #4472C4 !important;
    margin-bottom: 1rem;
    font-size: 1.4rem;
}

.keywords {
    background: #f8f9fa;
    border-left: 4px solid #4472C4;
    padding: 1.5rem;
    margin: 2rem 0;
    border-radius: 0 10px 10px 0;
}

.keywords h3 {
    color: #4472C4 !important;
    margin-bottom: 1rem;
}

/* Footer */
.footer {
    background: linear-gradient(135deg, #44546A 0%, #4472C4 100%);
    color: white;
    padding: 3rem 0;
    margin-top: 4rem;
}

.footer-content {
    display: flex;
    justify-content: space-between;
    align-items: center;
    flex-wrap: wrap;
    gap: 2rem;
}

.footer-logo-img {
    height: 80px;
    width: auto;
    filter: brightness(0) invert(1);
}

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

.footer-info p {
    margin: 0.5rem 0;
    opacity: 0.9;
}

/* Animations */
@keyframes fadeInUp {
    from {
        opacity: 0;
        transform: translateY(30px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

.zoom-effect {
    transform: scale(1.05);
    transition: transform 0.5s ease;
    box-shadow: 0 10px 30px rgba(68, 114, 196, 0.3);
}

/* Responsive Design */
@media (max-width: 768px) {
    .header-content {
        flex-direction: column;
        gap: 1rem;
    }
    
    .nav-list {
        flex-wrap: wrap;
        justify-content: center;
        gap: 1rem;
    }
    
    .hero {
        padding: 100px 0 60px;
        margin-top: 120px;
    }
    
    .hero-title {
        font-size: 2rem;
    }
    
    .toc-grid {
        grid-template-columns: 1fr;
    }
    
    .footer-content {
        flex-direction: column;
        text-align: center;
    }
    
    .footer-info {
        text-align: center;
    }
    
    .content-text {
        padding: 0 1rem;
    }
}

@media (max-width: 480px) {
    .hero-title {
        font-size: 1.5rem;
    }
    
    .section-title {
        font-size: 2rem;
    }
    
    .toc-item {
        padding: 1.5rem;
    }
    
    .content-section {
        padding: 60px 0;
    }
}

/* Smooth scrolling enhancement */
html {
    scroll-padding-top: 100px;
}

/* Loading animation for content */
.content-section {
    opacity: 0;
    animation: fadeInSection 0.8s ease-out forwards;
}

@keyframes fadeInSection {
    from {
        opacity: 0;
        transform: translateY(20px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

/* Hover effects for interactive elements */
.nav-link, .toc-item, .logo {
    will-change: transform;
}

/* Focus states for accessibility */
.nav-link:focus,
.toc-item:focus {
    outline: 2px solid #4472C4;
    outline-offset: 2px;
}

/* Print styles */
@media print {
    .header, .footer {
        display: none;
    }
    
    .hero {
        margin-top: 0;
        background: white;
        color: black;
    }
    
    .content-section {
        page-break-inside: avoid;
    }
}