:root {
    --bg-color: #184954;
    --text-color: #efe2cd;
    --accent-color: #fbc877;
    --secondary-color: #2a6d7a;
    --card-bg: #1e5a6b;
    --title-font: 'Sofia Sans', sans-serif;
    --text-font: 'Inter', sans-serif;
}

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

body {
    background-color: var(--bg-color);
    color: var(--text-color);
    font-family: var(--text-font);
    line-height: 1.6;
}

/* Navigation */
#navbar {
    width: 90%;
    height: 80px;
    margin: 0 auto;
    padding: 0 5%;
    display: flex;
    align-items: center;
    justify-content: space-between;
    gap: 2rem;
}

.nav-home {
    font-family: var(--title-font);
    font-size: 2rem;
    text-decoration: none;
    color: var(--text-color);
    transition: all 0.3s ease;
    font-weight: 500;
}

.nav-links {
    display: flex;
    gap: 1rem;
    align-items: center;
}

.nav-social {
    height: 2rem;
    width: 2rem;
    color: var(--text-color);
    transition: all 0.3s ease;
    display: flex;
    align-items: center;
    justify-content: center;
}

.nav-home:hover {
    color: var(--accent-color);
}

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

/* Page Header */
.page-header {
    padding: 3rem 5%;
    text-align: center;
    background-color: var(--secondary-color);
}

.page-header h1 {
    font-family: var(--title-font);
    font-size: 3rem;
    font-weight: 500;
    margin-bottom: 1rem;
    color: var(--text-color);
}

.page-header p {
    font-size: 1.2rem;
    opacity: 0.9;
    max-width: 600px;
    margin: 0 auto;
}

/* Publications Section */
#hal-publications {
    padding: 4rem 5%;
    max-width: 1000px;
    margin: 0 auto;
}

.publication {
    background: var(--card-bg);
    padding: 2.5rem;
    border-radius: 8px;
    margin-bottom: 2rem;
    border-left: 4px solid var(--accent-color);
}

.publication-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 1.5rem;
}

.publication-badge {
    background: var(--accent-color);
    color: var(--bg-color);
    padding: 0.25rem 0.75rem;
    border-radius: 20px;
    font-size: 0.8rem;
    font-weight: 600;
}

.publication-date {
    color: var(--accent-color);
    font-weight: 600;
}

.publication h2 {
    font-family: var(--title-font);
    font-size: 1.8rem;
    font-weight: 500;
    margin-bottom: 1rem;
    color: var(--text-color);
    line-height: 1.3;
}

.publication-authors {
    font-size: 1.1rem;
    margin-bottom: 1.5rem;
    color: var(--accent-color);
}

.publication-abstract {
    font-size: 1rem;
    line-height: 1.7;
    margin-bottom: 2rem;
    opacity: 0.9;
}

.publication-links {
    display: flex;
    gap: 1rem;
    margin-bottom: 1.5rem;
    flex-wrap: wrap;
}

.publication-meta {
    display: flex;
    gap: 0.5rem;
    flex-wrap: wrap;
}

.keyword {
    background: rgba(251, 200, 119, 0.1);
    color: var(--accent-color);
    padding: 0.25rem 0.75rem;
    border-radius: 4px;
    font-size: 0.8rem;
    border: 1px solid var(--accent-color);
}

/* Research Interests */
#research-interests {
    padding: 4rem 5%;
    background-color: var(--secondary-color);
}

#research-interests h2 {
    font-family: var(--title-font);
    font-size: 2.5rem;
    font-weight: 500;
    text-align: center;
    margin-bottom: 3rem;
    color: var(--text-color);
}

.interests-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: 2rem;
    max-width: 1200px;
    margin: 0 auto;
}

.interest-card {
    background: var(--card-bg);
    padding: 2rem;
    border-radius: 8px;
    text-align: center;
    transition: transform 0.3s ease;
}

.interest-card:hover {
    transform: translateY(-5px);
}

.interest-card h3 {
    font-family: var(--title-font);
    font-size: 1.3rem;
    margin-bottom: 1rem;
    color: var(--accent-color);
}

.interest-card p {
    font-size: 0.95rem;
    opacity: 0.9;
    line-height: 1.6;
}

/* Buttons */
.btn-primary, .btn-secondary {
    display: inline-block;
    padding: 0.75rem 1.5rem;
    text-decoration: none;
    border-radius: 4px;
    font-family: var(--text-font);
    font-weight: 500;
    transition: all 0.3s ease;
    border: 2px solid var(--accent-color);
    font-size: 0.9rem;
}

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

.btn-primary:hover {
    background-color: transparent;
    color: var(--accent-color);
}

.btn-secondary {
    background-color: transparent;
    color: var(--accent-color);
}

.btn-secondary:hover {
    background-color: var(--accent-color);
    color: var(--bg-color);
}

/* Footer */
footer {
    background-color: var(--card-bg);
    padding: 2rem 5%;
    margin-top: 4rem;
}

.footer-content {
    max-width: 1200px;
    margin: 0 auto;
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.footer-links {
    display: flex;
    gap: 2rem;
}

.footer-links a {
    color: var(--text-color);
    text-decoration: none;
    transition: color 0.3s ease;
}

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

/* Responsive Design */
@media (max-width: 768px) {
    .page-header h1 {
        font-size: 2.2rem;
    }
    
    .publication {
        padding: 1.5rem;
    }
    
    .publication-header {
        flex-direction: column;
        gap: 0.5rem;
        align-items: flex-start;
    }
    
    .publication h2 {
        font-size: 1.4rem;
    }
    
    .publication-links {
        flex-direction: column;
    }
    
    .interests-grid {
        grid-template-columns: 1fr;
    }
    
    .footer-content {
        flex-direction: column;
        gap: 1rem;
        text-align: center;
    }
    
    .footer-links {
        justify-content: center;
    }
    
    #navbar {
        flex-direction: column;
        height: auto;
        padding: 1rem 5%;
        gap: 1rem;
    }
    
    .nav-links {
        justify-content: center;
    }
}