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

:root {
    --primary-color: #2c3e50;
    --secondary-color: #3498db;
    --accent-color: #e74c3c;
    --text-color: #333;
    --light-bg: #f8f9fa;
    --white: #ffffff;
    --border-color: #e0e0e0;
    --shadow: 0 2px 4px rgba(0,0,0,0.1);
    --shadow-lg: 0 4px 6px rgba(0,0,0,0.1);
}

html {
    scroll-behavior: smooth;
}

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

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

/* Navigation */
.navbar {
    background-color: var(--primary-color);
    color: var(--white);
    padding: 1rem 0;
    position: sticky;
    top: 0;
    z-index: 1000;
    box-shadow: var(--shadow-lg);
}

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

.nav-title {
    font-size: 1.5rem;
    font-weight: 600;
}

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

.nav-link {
    color: var(--white);
    text-decoration: none;
    transition: color 0.3s;
    font-weight: 500;
}

.nav-link:hover,
.nav-link.active {
    color: var(--secondary-color);
}

/* Sections */
.section {
    padding: 4rem 0;
}

.section:nth-child(even) {
    background-color: var(--light-bg);
}

.section-title {
    font-size: 2rem;
    color: var(--primary-color);
    margin-bottom: 2rem;
    padding-bottom: 0.5rem;
    border-bottom: 3px solid var(--secondary-color);
    display: inline-block;
}

/* Personal Info Section */
.personal-info-content {
    display: grid;
    grid-template-columns: 250px 1fr;
    gap: 3rem;
    margin-top: 2rem;
}

.profile-image {
    text-align: center;
}

.profile-image img {
    width: 250px;
    height: 250px;
    border-radius: 50%;
    object-fit: cover;
    border: 5px solid var(--secondary-color);
    box-shadow: var(--shadow-lg);
}

.profile-details h3 {
    font-size: 1.8rem;
    color: var(--primary-color);
    margin-bottom: 0.5rem;
}

.position {
    font-size: 1.2rem;
    color: var(--secondary-color);
    font-weight: 600;
    margin-bottom: 0.25rem;
}

.institution {
    font-size: 1.1rem;
    color: var(--text-color);
    margin-bottom: 0.25rem;
}

.department {
    color: #666;
    margin-bottom: 1.5rem;
}

.contact-info {
    margin: 1.5rem 0;
    padding: 1rem;
    background-color: var(--light-bg);
    border-radius: 8px;
}

.contact-info p {
    margin: 0.5rem 0;
}

.contact-info a {
    color: var(--secondary-color);
    text-decoration: none;
}

.contact-info a:hover {
    text-decoration: underline;
}

.social-links {
    margin: 1.5rem 0;
    display: flex;
    gap: 1rem;
    flex-wrap: wrap;
}

.social-links a {
    padding: 0.5rem 1rem;
    background-color: var(--secondary-color);
    color: var(--white);
    text-decoration: none;
    border-radius: 5px;
    transition: background-color 0.3s;
}

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

.bio {
    margin-top: 1.5rem;
}

.bio h4 {
    color: var(--primary-color);
    margin-bottom: 0.75rem;
    font-size: 1.2rem;
}

/* Timeline Styles */
.timeline {
    position: relative;
    padding-left: 2rem;
}

.timeline::before {
    content: '';
    position: absolute;
    left: 0;
    top: 0;
    bottom: 0;
    width: 2px;
    background-color: var(--secondary-color);
}

.timeline-item {
    position: relative;
    margin-bottom: 2rem;
}

.timeline-item::before {
    content: '';
    position: absolute;
    left: -2.5rem;
    top: 0.5rem;
    width: 12px;
    height: 12px;
    border-radius: 50%;
    background-color: var(--secondary-color);
    border: 3px solid var(--white);
    box-shadow: 0 0 0 2px var(--secondary-color);
}

.timeline-date {
    font-weight: 600;
    color: var(--secondary-color);
    margin-bottom: 0.5rem;
}

.timeline-content h3 {
    color: var(--primary-color);
    margin-bottom: 0.5rem;
}

.timeline-content .institution {
    font-weight: 600;
    margin-bottom: 0.5rem;
}

.timeline-content .description {
    color: #666;
    margin: 0.25rem 0;
}

.description-list {
    margin-top: 0.5rem;
    padding-left: 1.5rem;
}

.description-list li {
    margin: 0.25rem 0;
    color: #666;
}

/* Publications Section */
.publication-category {
    margin-bottom: 2.5rem;
}

.publication-category h3 {
    color: var(--primary-color);
    margin-bottom: 1rem;
    font-size: 1.3rem;
}

.publication-list {
    list-style-position: outside;
    padding-left: 1.5rem;
}

.publication-list li {
    margin-bottom: 1.5rem;
    line-height: 1.8;
}

.pub-authors {
    display: block;
    margin-bottom: 0.25rem;
}

.pub-title {
    display: block;
    color: var(--primary-color);
    font-weight: 500;
    margin-bottom: 0.25rem;
}

.pub-venue {
    display: block;
    color: #666;
    margin-bottom: 0.5rem;
}

.pub-link {
    display: inline-block;
    margin-right: 1rem;
    padding: 0.25rem 0.75rem;
    background-color: var(--secondary-color);
    color: var(--white);
    text-decoration: none;
    border-radius: 3px;
    font-size: 0.9rem;
    transition: background-color 0.3s;
}

.pub-link:hover {
    background-color: var(--primary-color);
}

/* Academic Experience Section */
.experience-category {
    margin-bottom: 2.5rem;
}

.experience-category h3 {
    color: var(--primary-color);
    margin-bottom: 1rem;
    font-size: 1.3rem;
    padding-bottom: 0.5rem;
    border-bottom: 2px solid var(--border-color);
}

.experience-list {
    margin-top: 1rem;
}

.experience-item {
    margin-bottom: 1.5rem;
    padding: 1rem;
    background-color: var(--white);
    border-radius: 8px;
    box-shadow: var(--shadow);
}

.section:nth-child(even) .experience-item {
    background-color: var(--white);
}

.experience-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 0.5rem;
}

.experience-item h4 {
    color: var(--primary-color);
    font-size: 1.1rem;
}

.experience-date {
    color: var(--secondary-color);
    font-weight: 600;
    font-size: 0.9rem;
}

.experience-item p {
    margin: 0.5rem 0;
    color: #666;
}

.experience-item ul {
    margin-top: 0.5rem;
    padding-left: 1.5rem;
}

.experience-item ul li {
    margin: 0.25rem 0;
    color: #666;
}

/* Footer */
footer {
    background-color: var(--primary-color);
    color: var(--white);
    padding: 2rem 0;
    text-align: center;
}

footer p {
    margin: 0.5rem 0;
}

/* Responsive Design */
@media (max-width: 768px) {
    .nav-menu {
        flex-wrap: wrap;
        gap: 1rem;
        justify-content: center;
    }

    .navbar .container {
        flex-direction: column;
        gap: 1rem;
    }

    .personal-info-content {
        grid-template-columns: 1fr;
        gap: 2rem;
    }

    .profile-image img {
        width: 200px;
        height: 200px;
    }

    .section {
        padding: 2rem 0;
    }

    .section-title {
        font-size: 1.5rem;
    }

    .timeline {
        padding-left: 1.5rem;
    }

    .experience-header {
        flex-direction: column;
        align-items: flex-start;
        gap: 0.5rem;
    }

    .nav-link {
        font-size: 0.9rem;
    }
}

@media (max-width: 480px) {
    .container {
        padding: 0 15px;
    }

    .profile-image img {
        width: 150px;
        height: 150px;
    }

    .social-links {
        flex-direction: column;
    }

    .social-links a {
        text-align: center;
    }
}