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

:root {
    --primary-color: #1a1a2e;
    --secondary-color: #16213e;
    --accent-color: #0f3460;
    --text-color: #333;
    --text-light: #666;
    --bg-color: #ffffff;
    --bg-alt: #f8f9fa;
    --border-color: #e0e0e0;
    --link-color: #2563eb;
    --link-hover: #1d4ed8;
    --award-color: #dc2626;
    --shadow: 0 2px 8px rgba(0, 0, 0, 0.1);
    --shadow-lg: 0 4px 16px rgba(0, 0, 0, 0.15);
}

html {
    scroll-behavior: smooth;
}

body {
    font-family: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, Oxygen, Ubuntu, Cantarell, sans-serif;
    line-height: 1.6;
    color: var(--text-color);
    background-color: var(--bg-color);
    font-size: 16px;
}

h1, h2, h3 {
    font-family: 'Merriweather', Georgia, serif;
    font-weight: 700;
    line-height: 1.2;
    margin-bottom: 1rem;
}

h1 {
    font-size: 2.5rem;
    color: var(--primary-color);
}

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

.collapsible-header {
    cursor: pointer;
    user-select: none;
    display: flex;
    justify-content: space-between;
    align-items: center;
    transition: color 0.3s ease;
}

.collapsible-header:hover {
    color: var(--link-color);
}

.toggle-icon {
    font-size: 1rem;
    transition: transform 0.3s ease;
    margin-left: 1rem;
}

.collapsible-header.active .toggle-icon {
    transform: rotate(180deg);
}

.collapsible-content {
    overflow: hidden;
    max-height: 0;
    opacity: 0;
    padding-top: 0;
    transition: max-height 0.6s ease-in-out, opacity 0.6s ease-in-out, padding 0.6s ease-in-out;
}

.collapsible-content.active {
    max-height: 100000px;
    opacity: 1;
    padding-top: 1rem;
}

.research-area {
    margin-bottom: 2rem;
}

.research-area h3.collapsible-header {
    font-size: 1.5rem;
    margin-bottom: 0;
    padding: 1rem 0;
    border-bottom: 2px solid var(--border-color);
}

.research-area .collapsible-content {
    padding-left: 0;
    padding-right: 0;
}

h3 {
    font-size: 1.25rem;
    margin-bottom: 0.5rem;
}

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

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

.container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 2rem;
}

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

.nav-container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 2rem;
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.nav-logo {
    font-size: 1.5rem;
    font-weight: 700;
    color: white;
    text-decoration: none;
}

.nav-logo:hover {
    text-decoration: none;
    opacity: 0.9;
}

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

.nav-link {
    color: white;
    text-decoration: none;
    font-weight: 500;
    transition: opacity 0.3s ease;
}

.nav-link:hover {
    opacity: 0.8;
    text-decoration: none;
}

.nav-toggle {
    display: none;
    flex-direction: column;
    background: none;
    border: none;
    cursor: pointer;
    padding: 0.5rem;
}

.nav-toggle span {
    width: 25px;
    height: 3px;
    background-color: white;
    margin: 3px 0;
    transition: 0.3s;
}

/* Hero Section */
.hero {
    background: linear-gradient(135deg, var(--bg-alt) 0%, var(--bg-color) 100%);
    padding: 4rem 0;
    margin-top: 0;
}

.hero-content {
    display: grid;
    grid-template-columns: 300px 1fr;
    gap: 3rem;
    align-items: start;
}

.profile-image {
    width: 300px;
    height: 450px;
    overflow: hidden;
    border-radius: 8px;
    box-shadow: var(--shadow-lg);
}

.profile-image img {
    width: 100%;
    height: 100%;
    object-fit: cover;
}

.hero-text h1 {
    margin-top: 0;
    margin-bottom: 1rem;
}

.title {
    font-size: 1.25rem;
    font-weight: 600;
    color: var(--primary-color);
    margin-bottom: 0.5rem;
}

.affiliation {
    color: var(--text-light);
    margin-bottom: 0.5rem;
    font-size: 0.95rem;
}

.affiliation a {
    color: var(--link-color);
}

.contact-info {
    margin-top: 1.5rem;
    padding-top: 1.5rem;
    border-top: 1px solid var(--border-color);
}

.contact-info p {
    margin-bottom: 1rem;
}

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

.btn {
    display: inline-block;
    padding: 0.5rem 1.5rem;
    border-radius: 6px;
    font-weight: 500;
    transition: all 0.3s ease;
    text-decoration: none;
}

.btn-outline {
    background-color: transparent;
    border: 2px solid var(--link-color);
    color: var(--link-color);
}

.btn-outline:hover {
    background-color: var(--link-color);
    color: white;
    text-decoration: none;
}

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

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

.content {
    max-width: 900px;
}

.research-themes {
    list-style: none;
    padding-left: 0;
    margin: 1.5rem 0;
}

.research-themes li {
    padding: 1rem;
    margin-bottom: 1rem;
    background-color: var(--bg-alt);
    border-left: 4px solid var(--accent-color);
    border-radius: 4px;
}

.research-themes li::before {
    content: "→";
    color: var(--accent-color);
    font-weight: bold;
    margin-right: 0.5rem;
}

/* Publications */
.publications-list {
    display: flex;
    flex-direction: column;
    gap: 2rem;
}

.publication-item {
    padding: 1.5rem;
    background-color: white;
    border-radius: 8px;
    box-shadow: var(--shadow);
    transition: transform 0.3s ease, box-shadow 0.3s ease;
}

.publication-item:hover {
    transform: translateY(-2px);
    box-shadow: var(--shadow-lg);
}

.publication-item h3 {
    margin-bottom: 0.75rem;
}

.publication-item h3 a {
    color: var(--primary-color);
    font-size: 1.1rem;
}

.publication-item h3 a:hover {
    color: var(--link-color);
}

.authors {
    color: var(--text-light);
    font-style: italic;
    margin-bottom: 0.5rem;
}

.venue {
    color: var(--text-color);
    font-weight: 500;
    margin-bottom: 0.5rem;
}

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

.note {
    color: var(--text-light);
    font-size: 0.95rem;
    margin-top: 0.5rem;
    font-style: italic;
}

.note-text {
    color: var(--text-light);
    font-size: 0.9rem;
    margin-bottom: 2rem;
    font-style: italic;
}

.links {
    margin: 0.5rem 0;
}

.links a {
    margin-right: 1rem;
    font-size: 0.9rem;
}

.section-subtitle {
    margin-top: 3rem;
    margin-bottom: 1.5rem;
    font-size: 1.5rem;
    color: var(--primary-color);
    border-bottom: 2px solid var(--border-color);
    padding-bottom: 0.5rem;
}

/* Footer */
.footer {
    background-color: var(--primary-color);
    color: white;
    padding: 2rem 0;
    text-align: center;
    margin-top: 4rem;
}

.footer p {
    margin: 0;
}

/* Responsive Design */
@media (max-width: 768px) {
    .nav-menu {
        position: fixed;
        left: -100%;
        top: 70px;
        flex-direction: column;
        background-color: var(--primary-color);
        width: 100%;
        text-align: center;
        transition: 0.3s;
        box-shadow: var(--shadow);
        padding: 2rem 0;
    }

    .nav-menu.active {
        left: 0;
    }

    .nav-toggle {
        display: flex;
    }

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

    .profile-image {
        width: 100%;
        max-width: 300px;
        margin: 0 auto;
    }

    h1 {
        font-size: 2rem;
    }

    h2 {
        font-size: 1.75rem;
    }

    .container {
        padding: 0 1rem;
    }

    .section {
        padding: 2rem 0;
    }

    .publication-item {
        padding: 1rem;
    }
}

@media (max-width: 480px) {
    h1 {
        font-size: 1.75rem;
    }

    h2 {
        font-size: 1.5rem;
    }

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

    .btn {
        width: 100%;
        text-align: center;
    }
}

/* Print Styles */
@media print {
    .navbar,
    .footer,
    #chat-window {
        display: none;
    }

    .section {
        page-break-inside: avoid;
    }
}