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

:root {
    --primary-color: #1a1a2e;
    --secondary-color: #16213e;
    --accent-color: #0f3460;
    --text-color: #333;
    --light-bg: #f8f9fa;
    --white: #ffffff;
    --border-color: #e0e0e0;
    --link-color: #2c5f8d;
    --link-hover: #1a3a52;
}

body {
    font-family: 'Georgia', 'Times New Roman', 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: 0 2px 5px rgba(0,0,0,0.1);
}

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

.nav-brand {
    font-size: 1.5rem;
    font-weight: bold;
}

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

.nav-menu a {
    color: var(--white);
    text-decoration: none;
    transition: opacity 0.3s;
}

.nav-menu a:hover {
    opacity: 0.8;
}

/* Hero Section */
.hero {
    background: linear-gradient(135deg, var(--primary-color) 0%, var(--secondary-color) 100%);
    color: var(--white);
    padding: 4rem 0;
}

.hero-content {
    display: grid;
    grid-template-columns: 1fr 2fr;
    gap: 3rem;
    align-items: center;
}

.hero-image img {
    width: 250px;
    height: 250px;
    border-radius: 50%;
    object-fit: cover;
    border: 5px solid var(--white);
    box-shadow: 0 4px 15px rgba(0,0,0,0.2);
}

.hero-text h1 {
    font-size: 3rem;
    margin-bottom: 0.5rem;
}

.subtitle {
    font-size: 1.3rem;
    margin-bottom: 0.3rem;
    opacity: 0.9;
}

.affiliation {
    font-size: 1.1rem;
    margin-bottom: 1rem;
    opacity: 0.85;
}

.quote {
    font-style: italic;
    font-size: 1rem;
    margin: 1.5rem 0;
    opacity: 0.9;
    border-left: 3px solid var(--white);
    padding-left: 1rem;
}

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

.social-icon {
    width: 32px;
    height: 32px;
    transition: transform 0.3s;
    background-color: var(--white);
    border-radius: 4px;
    padding: 2px;
}

.social-icon:hover {
    transform: scale(1.1);
}

.btn-primary {
    display: inline-block;
    background-color: var(--accent-color);
    color: var(--white);
    padding: 0.8rem 2rem;
    text-decoration: none;
    border-radius: 5px;
    margin-top: 1rem;
    transition: background-color 0.3s;
}

.btn-primary:hover {
    background-color: #0a2440;
}

.btn-secondary {
    display: inline-block;
    background-color: var(--link-color);
    color: var(--white);
    padding: 0.8rem 2rem;
    text-decoration: none;
    border-radius: 5px;
    margin-top: 1rem;
    transition: background-color 0.3s;
}

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

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

.bg-light {
    background-color: var(--light-bg);
}

.section h2 {
    font-size: 2.5rem;
    margin-bottom: 2rem;
    color: var(--primary-color);
    border-bottom: 3px solid var(--accent-color);
    padding-bottom: 0.5rem;
}

.section p {
    margin-bottom: 1rem;
    text-align: justify;
}

/* Research Section */
.research-areas {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: 2rem;
    margin-bottom: 3rem;
}

.research-card {
    background-color: var(--white);
    padding: 1.5rem;
    border-radius: 8px;
    box-shadow: 0 2px 10px rgba(0,0,0,0.1);
    transition: transform 0.3s, box-shadow 0.3s;
}

.research-card:hover {
    transform: translateY(-5px);
    box-shadow: 0 4px 20px rgba(0,0,0,0.15);
}

.research-card h3 {
    color: var(--accent-color);
    margin-bottom: 0.5rem;
    font-size: 1.3rem;
}

.subsection-title {
    font-size: 1.8rem;
    margin: 2rem 0 1rem 0;
    color: var(--secondary-color);
}

.projects-list {
    list-style-position: inside;
    margin-left: 1rem;
}

.projects-list li {
    margin-bottom: 1rem;
    line-height: 1.6;
}

/* Publications Section */
.pub-category {
    font-size: 1.8rem;
    margin: 2rem 0 1rem 0;
    color: var(--secondary-color);
}

.publication {
    margin-bottom: 2rem;
    padding-bottom: 1.5rem;
    border-bottom: 1px solid var(--border-color);
}

.pub-title {
    font-weight: bold;
    font-size: 1.1rem;
    margin-bottom: 0.3rem;
    color: var(--primary-color);
}

.pub-authors {
    font-style: italic;
    margin-bottom: 0.3rem;
}

.pub-venue {
    color: #555;
    margin-bottom: 0.3rem;
}

.pub-doi a {
    color: var(--link-color);
    text-decoration: none;
}

.pub-doi a:hover {
    color: var(--link-hover);
    text-decoration: underline;
}

.pub-note {
    font-size: 0.95rem;
    color: #666;
    margin-top: 0.3rem;
}

.text-center {
    text-align: center;
    margin-top: 2rem;
}

/* Teaching Section */
.affiliation-title {
    font-size: 1.5rem;
    color: var(--accent-color);
    margin-top: 2rem;
    margin-bottom: 0.5rem;
}

.teaching-period {
    font-style: italic;
    color: #666;
    margin-bottom: 1rem;
}

.teaching-list {
    list-style-position: inside;
    margin-left: 1rem;
    margin-bottom: 2rem;
}

.teaching-list li {
    margin-bottom: 0.5rem;
}

/* Contact Section */
.contact-info {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: 2rem;
    margin-top: 2rem;
}

.contact-item h3 {
    color: var(--accent-color);
    margin-bottom: 0.5rem;
    font-size: 1.3rem;
}

.contact-item a {
    color: var(--link-color);
    text-decoration: none;
}

.contact-item a:hover {
    color: var(--link-hover);
    text-decoration: underline;
}

/* Footer */
footer {
    background-color: var(--primary-color);
    color: var(--white);
    text-align: center;
    padding: 2rem 0;
    margin-top: 3rem;
}

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

    .hero-content {
        grid-template-columns: 1fr;
        text-align: center;
    }

    .hero-image img {
        margin: 0 auto;
    }

    .hero-text h1 {
        font-size: 2rem;
    }

    .research-areas {
        grid-template-columns: 1fr;
    }

    .contact-info {
        grid-template-columns: 1fr;
    }

    .social-links {
        justify-content: center;
    }
}

@media (max-width: 480px) {
    .hero-text h1 {
        font-size: 1.8rem;
    }

    .section h2 {
        font-size: 2rem;
    }
}