:root {
    --primary-color: #2c3e50;
    --secondary-color: #34495e;
    --accent-color: #7f8c8d;
    --text-color: #2c3e50;
    --text-secondary: #5d6d7e;
    --background-color: #ffffff;
    --section-background: #f8f9fa;
    --border-color: #dee2e6;
    --nav-background: #ffffff;
    --shadow: 0 1px 3px 0 rgba(0, 0, 0, 0.05), 0 1px 2px 0 rgba(0, 0, 0, 0.03);
    --shadow-lg: 0 4px 6px -1px rgba(0, 0, 0, 0.08), 0 2px 4px -1px rgba(0, 0, 0, 0.04);
}

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

body {
    font-family: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
    line-height: 1.6;
    color: var(--text-color);
    background-color: var(--background-color);
}

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

/* Navigation */
.navigation {
    background: var(--nav-background);
    border-bottom: 1px solid var(--border-color);
    padding: 15px 0;
    margin-bottom: 0;
}

.navigation ul {
    list-style: none;
    display: flex;
    gap: 40px;
    margin: 0;
    padding: 0;
}

.navigation li {
    margin: 0;
}

.navigation a {
    color: var(--text-color);
    text-decoration: none;
    font-weight: 500;
    font-size: 1rem;
    padding: 8px 16px;
    border-radius: 6px;
    transition: all 0.2s ease;
}

.navigation a:hover {
    background: var(--section-background);
    color: var(--primary-color);
}

.navigation a.active {
    background: var(--primary-color);
    color: white;
}

/* Headers */
.header {
    padding: 60px 0;
    background: var(--section-background);
    border-bottom: 1px solid var(--border-color);
}

.page-header {
    padding: 40px 0;
    text-align: center;
    border-bottom: 1px solid var(--border-color);
}

.page-header h1 {
    font-size: 2.5rem;
    font-weight: 600;
    color: var(--primary-color);
}

.profile-section {
    display: flex;
    align-items: center;
    gap: 40px;
    flex-wrap: wrap;
}

.profile-image img {
    width: 200px;
    height: 240px;
    object-fit: cover;
    border-radius: 8px;
    box-shadow: var(--shadow-lg);
}

.profile-info {
    flex: 1;
    min-width: 300px;
}

.profile-info h1 {
    font-size: 3rem;
    font-weight: 700;
    color: var(--primary-color);
    margin-bottom: 10px;
    letter-spacing: -0.025em;
}

.title {
    font-size: 1.5rem;
    font-weight: 500;
    color: var(--text-secondary);
    margin-bottom: 10px;
}

.affiliation {
    font-size: 1.1rem;
    margin-bottom: 20px;
}

.affiliation a {
    color: var(--secondary-color);
    text-decoration: none;
    font-weight: 500;
}

.affiliation a:hover {
    text-decoration: underline;
}

.btn-cv {
    display: inline-block;
    background: var(--primary-color);
    color: white;
    padding: 12px 24px;
    border-radius: 6px;
    text-decoration: none;
    font-weight: 500;
    transition: all 0.3s ease;
    box-shadow: var(--shadow);
}

.btn-cv:hover {
    background: var(--secondary-color);
    transform: translateY(-1px);
    box-shadow: var(--shadow-lg);
}

main {
    padding: 60px 0;
}

section {
    margin-bottom: 60px;
}

h2 {
    font-size: 2rem;
    font-weight: 600;
    color: var(--primary-color);
    margin-bottom: 30px;
    padding-bottom: 8px;
    border-bottom: 2px solid var(--border-color);
}

.about p, .research p, .teaching p {
    font-size: 1.1rem;
    line-height: 1.7;
    margin-bottom: 20px;
    color: var(--text-color);
}

.about a, .research a, .teaching a {
    color: var(--secondary-color);
    text-decoration: none;
}

.about a:hover, .research a:hover, .teaching a:hover {
    text-decoration: underline;
}

.paper {
    background: var(--background-color);
    padding: 25px;
    margin-bottom: 25px;
    border-radius: 8px;
    border: 1px solid var(--border-color);
    box-shadow: var(--shadow);
    transition: transform 0.2s ease, box-shadow 0.2s ease;
}

.paper:hover {
    transform: translateY(-1px);
    box-shadow: var(--shadow-lg);
}

.paper h3 {
    font-size: 1.2rem;
    font-weight: 600;
    margin-bottom: 12px;
    line-height: 1.4;
}

.paper h3 a {
    color: var(--primary-color);
    text-decoration: none;
}

.paper h3 a:hover {
    color: var(--secondary-color);
    text-decoration: underline;
}

.authors {
    font-size: 1rem;
    color: var(--text-secondary);
    margin-bottom: 8px;
    font-weight: 500;
}

.journal {
    font-size: 1rem;
    margin-bottom: 15px;
    font-weight: 500;
    color: var(--text-color);
}

.awards {
    display: flex;
    flex-direction: column;
    gap: 8px;
}

.award {
    background: var(--accent-color);
    color: white;
    padding: 6px 12px;
    border-radius: 16px;
    font-size: 0.875rem;
    font-weight: 500;
    display: inline-block;
    width: fit-content;
}

.footer {
    background: var(--section-background);
    border-top: 1px solid var(--border-color);
    padding: 30px 0;
    text-align: center;
    color: var(--text-secondary);
    margin-top: 40px;
}

.course {
    padding: 0;
    margin-bottom: 15px;
    border-radius: 0;
    border: none;
    box-shadow: none;
    background: none;
}

.course h3 {
    font-size: 1.1rem;
    font-weight: 500;
    color: var(--text-color);
    margin-bottom: 3px;
    display: inline;
}

.course-info {
    font-size: 1rem;
    color: var(--text-secondary);
    margin-bottom: 8px;
    font-weight: 400;
    display: inline;
    margin-left: 8px;
}

.course .awards {
    margin-top: 5px;
}

/* Responsive Design */
@media (max-width: 768px) {
    .container {
        padding: 0 15px;
    }
    
    .navigation ul {
        gap: 20px;
        flex-wrap: wrap;
    }
    
    .navigation a {
        padding: 6px 12px;
        font-size: 0.9rem;
    }
    
    .profile-section {
        flex-direction: column;
        text-align: center;
        gap: 20px;
    }
    
    .profile-info h1 {
        font-size: 2.5rem;
    }
    
    .profile-image img {
        width: 180px;
        height: 216px;
    }
    
    .page-header h1 {
        font-size: 2rem;
    }
    
    h2 {
        font-size: 1.75rem;
    }
    
    .paper {
        padding: 20px;
    }
    
    .header {
        padding: 40px 0;
    }
    
    main {
        padding: 40px 0;
    }
    
    section {
        margin-bottom: 40px;
    }
}

@media (max-width: 480px) {
    .navigation ul {
        gap: 15px;
    }
    
    .navigation a {
        padding: 5px 10px;
        font-size: 0.85rem;
    }
    
    .profile-info h1 {
        font-size: 2rem;
    }
    
    .title {
        font-size: 1.25rem;
    }
    
    .affiliation {
        font-size: 1rem;
    }
    
    .page-header h1 {
        font-size: 1.75rem;
    }
    
    h2 {
        font-size: 1.5rem;
    }
    
    .paper h3 {
        font-size: 1.1rem;
    }
    
    .paper {
        padding: 15px;
    }
}

/* Print styles */
@media print {
    .container {
        max-width: none;
        margin: 0;
        padding: 0;
    }
    
    .navigation {
        display: none;
    }
    
    .header {
        background: none;
        border-bottom: 1px solid #000;
    }
    
    .paper {
        background: none;
        box-shadow: none;
        border: 1px solid #ccc;
        break-inside: avoid;
        margin-bottom: 20px;
    }
    
    .btn-cv {
        display: none;
    }
    
    .page-header {
        border-bottom: 2px solid #000;
    }
    
    .footer {
        background: none;
        border-top: 1px solid #000;
    }
}
