/* Reset and Base Styles */
* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

body {
    font-family: 'Titillium Web', Arial, sans-serif;
    font-weight: 400;
    line-height: 1.6;
    color: #333;
    background-color: #eaeaea;
}

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

/* Header Styles */
.site-header {
    background: linear-gradient(135deg, #454e5c 0%, #2c3e50 100%);
    color: white;
    padding: 1rem 0;
    position: fixed;
    top: 0;
    width: 100%;
    z-index: 1000;
    box-shadow: 0 2px 10px rgba(0, 0, 0, 0.1);
}

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

.site-title {
    font-size: 1.8rem;
    font-weight: 600;
    color: white;
    text-decoration: none;
}

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

.main-nav a {
    color: white;
    text-decoration: none;
    font-weight: 300;
    transition: color 0.3s ease;
}

.main-nav a:hover {
    color: #ccc;
}

/* Main Content */
.main-content {
    margin-top: 80px;
}

/* Hero Section */
.hero-section {
    background: linear-gradient(135deg, #454e5c 0%, #2c3e50 100%);
    color: white;
    padding: 4rem 0;
    text-align: center;
    position: relative;
    overflow: hidden;
}

.hero-background {
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    z-index: 1;
}

.hero-bg-image {
    width: 100%;
    height: 100%;
    object-fit: cover;
    opacity: 0.3;
}

.hero-section .container {
    position: relative;
    z-index: 2;
}

.hero-title {
    font-size: 2.5rem;
    font-weight: 600;
    margin-bottom: 5rem;
    line-height: 1.2;
}

.hero-subtitle {
    font-size: 1.2rem;
    font-weight: 300;
    max-width: 800px;
    margin: 0 auto;
    opacity: 0.9;
}

/* Downloads Section */
.downloads-section {
    padding: 4rem 0;
    background: white;
}

.downloads-section h3 {
    text-align: center;
    font-size: 2rem;
    font-weight: 600;
    margin-bottom: 3rem;
    color: #454e5c;
}

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

.download-card {
    background: #f8f9fa;
    border-radius: 8px;
    padding: 2rem;
    text-align: center;
    box-shadow: 0 4px 6px rgba(0, 0, 0, 0.1);
    transition: transform 0.3s ease, box-shadow 0.3s ease;
}

.download-icon {
    width: 48px;
    height: 48px;
    margin: 0 auto 1rem;
    display: block;
}

.download-card:hover {
    transform: translateY(-5px);
    box-shadow: 0 8px 15px rgba(0, 0, 0, 0.15);
}

.download-card h4 {
    font-size: 1.5rem;
    font-weight: 600;
    color: #454e5c;
    margin-bottom: 1rem;
}

.download-card p {
    color: #666;
    margin-bottom: 1rem;
}

.file-size {
    display: inline-block;
    background: #e9ecef;
    color: #495057;
    padding: 0.25rem 0.5rem;
    border-radius: 4px;
    font-size: 0.9rem;
    margin-bottom: 1rem;
}

.download-btn {
    display: inline-block;
    background: #454e5c;
    color: white;
    padding: 0.75rem 1.5rem;
    text-decoration: none;
    border-radius: 5px;
    font-weight: 600;
    transition: background-color 0.3s ease;
}

.download-btn:hover {
    background: #2c3e50;
}

/* Research Section */
.research-section {
    padding: 4rem 0;
    background: #f8f9fa;
}

.research-section h3 {
    text-align: center;
    font-size: 2rem;
    font-weight: 600;
    margin-bottom: 3rem;
    color: #454e5c;
}

.research-grid {
    display: flex;
    flex-direction: column;
    gap: 2rem;
    margin-bottom: 3rem;
}

.research-item {
    background: white;
    border-radius: 8px;
    padding: 2rem 3rem;
    box-shadow: 0 2px 4px rgba(0, 0, 0, 0.1);
    max-width: 100%;
}

.research-item h4 {
    font-size: 1.3rem;
    font-weight: 600;
    color: #454e5c;
    margin-bottom: 1rem;
}

.research-item p {
    color: #666;
    line-height: 1.5;
}

.research-item ol {
    color: #666;
    line-height: 1.8;
    padding-left: 1.5rem;
}

.research-item ol li {
    margin-bottom: 0.75rem;
}

.research-stats {
    display: flex;
    justify-content: center;
    gap: 3rem;
    flex-wrap: wrap;
    margin-top: 3rem;
}

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

.stat-number {
    display: block;
    font-size: 2.5rem;
    font-weight: 600;
    color: #454e5c;
    line-height: 1;
}

.stat-label {
    font-size: 1rem;
    color: #666;
    font-weight: 300;
}

/* Authors Section */
.authors-section {
    padding: 4rem 0;
    background: white;
}

.authors-section h3 {
    text-align: center;
    font-size: 2rem;
    font-weight: 600;
    margin-bottom: 3rem;
    color: #454e5c;
}

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

.author-card {
    background: #f8f9fa;
    border-radius: 8px;
    padding: 2rem;
    text-align: center;
    box-shadow: 0 2px 4px rgba(0, 0, 0, 0.1);
    transition: transform 0.3s ease;
    display: flex;
    flex-direction: column;
    align-items: center;
}

.author-avatar {
    width: 120px;
    height: 120px;
    margin-bottom: 1rem;
    background: white;
    box-shadow: 0 2px 8px rgba(0, 0, 0, 0.1);
}

.author-card:hover {
    transform: translateY(-3px);
}

.author-info h4 {
    font-size: 1.3rem;
    font-weight: 600;
    color: #454e5c;
    margin-bottom: 0.5rem;
}

.author-role {
    color: #666;
    font-weight: 600;
    margin-bottom: 1rem;
}

.author-description {
    color: #666;
    font-size: 0.9rem;
    line-height: 1.4;
}

.author-description a {
    color: #454e5c;
    text-decoration: none;
    transition: color 0.3s ease;
}

.author-description a:hover {
    color: #2c3e50;
    text-decoration: underline;
}

/* Footer */
.site-footer {
    background: #454e5c;
    color: white;
    padding: 2rem 0;
    text-align: center;
}

.site-footer p {
    margin-bottom: 0.5rem;
    font-weight: 300;
}

.site-footer a {
    color: #ccc;
    text-decoration: none;
    transition: color 0.3s ease;
}

.site-footer a:hover {
    color: white;
    text-decoration: underline;
}

/* Responsive Design */
@media (max-width: 768px) {
    .site-header .container {
        flex-direction: column;
        gap: 1rem;
    }
    
    .main-nav ul {
        gap: 1rem;
    }
    
    .hero-title {
        font-size: 2rem;
    }
    
    .hero-subtitle {
        font-size: 1rem;
    }
    
    .downloads-grid,
    .authors-grid {
        grid-template-columns: 1fr;
    }
    
    .research-stats {
        gap: 2rem;
    }
    
    .stat-number {
        font-size: 2rem;
    }
}

@media (max-width: 480px) {
    .container {
        padding: 0 15px;
    }
    
    .hero-section {
        padding: 2rem 0;
    }
    
    .downloads-section,
    .research-section,
    .authors-section {
        padding: 2rem 0;
    }
    
    .download-card,
    .research-item,
    .author-card {
        padding: 1.5rem;
    }
}