/* Base styles */
:root {
    --primary-color: #2c3e50;
    --accent-color: #3498db;
    --text-color: #333;
    --light-bg: #f8f9fa;
    --spacing: 2rem;
}

body {
    font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Helvetica, Arial, sans-serif;
    line-height: 1.6;
    color: var(--text-color);
    margin: 0;
    padding: 0;
}

.container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 var(--spacing);
}

/* Header styles */
.site-header {
    background: var(--primary-color);
    color: white;
    padding: var(--spacing) 0;
}

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

.profile-pic {
    width: 180px;
    height: 180px;
    border-radius: 50%;
    border: 4px solid white;
}

.profile-info h1 {
    margin: 0;
    font-size: 2.5rem;
}

.tagline {
    font-style: italic;
    margin-top: 0.5rem;
}

/* Navigation styles */
.site-nav {
    background: var(--light-bg);
    padding: 1rem 0;
    border-bottom: 1px solid #ddd;
}

.site-nav ul {
    list-style: none;
    padding: 0;
    margin: 0;
    display: flex;
    gap: 2rem;
}

.site-nav a {
    color: var(--primary-color);
    text-decoration: none;
    font-weight: 500;
    padding: 0.5rem 1rem;
    border-radius: 4px;
    transition: background-color 0.3s;
}

.site-nav a:hover,
.site-nav a.active {
    background-color: var(--accent-color);
    color: white;
}

/* Content styles */
.project-card,
.publication-card {
    background: white;
    border-radius: 8px;
    padding: var(--spacing);
    margin-bottom: var(--spacing);
    box-shadow: 0 2px 4px rgba(0,0,0,0.1);
}

.project-card h2,
.publication-card h2 {
    color: var(--primary-color);
    margin-top: 0;
}

.tag {
    display: inline-block;
    background: var(--light-bg);
    padding: 0.25rem 0.75rem;
    border-radius: 16px;
    font-size: 0.875rem;
    margin-right: 0.5rem;
    margin-bottom: 0.5rem;
}

/* Footer styles */
.site-footer {
    background: var(--primary-color);
    color: white;
    padding: var(--spacing) 0;
    margin-top: var(--spacing);
}

.social-links {
    display: flex;
    justify-content: center;
    gap: 2rem;
}

.social-links a {
    color: white;
    font-size: 1.5rem;
    transition: color 0.3s;
}

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

/* Responsive design */
@media (max-width: 768px) {
    .profile-header {
        flex-direction: column;
        text-align: center;
    }

    .site-nav ul {
        flex-direction: column;
        text-align: center;
        gap: 1rem;
    }
}