:root {
    --primary: #1a365d;
    --primary-light: #2c5282;
    --accent: #e53e3e;
    --accent-light: #fc8181;
    --background: #ffffff;
    --background-alt: #f7fafc;
    --text: #1a202c;
    --text-light: #4a5568;
    --text-muted: #718096;
    --border: #e2e8f0;
    --shadow: 0 4px 6px -1px rgba(0, 0, 0, 0.1), 0 2px 4px -1px rgba(0, 0, 0, 0.06);
    --shadow-lg: 0 10px 15px -3px rgba(0, 0, 0, 0.1), 0 4px 6px -2px rgba(0, 0, 0, 0.05);
}

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

html {
    scroll-behavior: smooth;
}

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

a {
    color: inherit;
    text-decoration: none;
}

/* Navigation */
.nav {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    background: rgba(255, 255, 255, 0.95);
    backdrop-filter: blur(10px);
    border-bottom: 1px solid var(--border);
    z-index: 1000;
    padding: 1rem 2rem;
}

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

.nav-logo {
    font-size: 1.25rem;
    font-weight: 700;
    color: var(--primary);
}

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

.nav-links a {
    color: var(--text-light);
    font-weight: 500;
    transition: color 0.2s;
    font-size: 0.95rem;
}

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

/* Hero Section */
.hero {
    min-height: 100vh;
    display: flex;
    align-items: center;
    padding: 8rem 2rem 4rem;
    background: linear-gradient(135deg, var(--primary) 0%, var(--primary-light) 100%);
    color: white;
    position: relative;
    overflow: hidden;
}

.hero::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background: url("data:image/svg+xml,%3Csvg width='60' height='60' viewBox='0 0 60 60' xmlns='http://www.w3.org/2000/svg'%3E%3Cg fill='none' fill-rule='evenodd'%3E%3Cg fill='%23ffffff' fill-opacity='0.05'%3E%3Cpath d='M36 34v-4h-2v4h-4v2h4v4h2v-4h4v-2h-4zm0-30V0h-2v4h-4v2h4v4h2V6h4V4h-4zM6 34v-4H4v4H0v2h4v4h2v-4h4v-2H6zM6 4V0H4v4H0v2h4v4h2V6h4V4H6z'/%3E%3C/g%3E%3C/g%3E%3C/svg%3E");
}

.hero-container {
    max-width: 1200px;
    margin: 0 auto;
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 4rem;
    align-items: center;
    position: relative;
    z-index: 1;
}

.hero-content h1 {
    font-size: 3.5rem;
    font-weight: 800;
    margin-bottom: 0.5rem;
    line-height: 1.1;
}

.hero-content .title {
    font-size: 1.5rem;
    opacity: 0.9;
    margin-bottom: 1.5rem;
    font-weight: 400;
}

.hero-content .affiliation {
    font-size: 1.1rem;
    opacity: 0.8;
    margin-bottom: 2rem;
}

.hero-content p {
    font-size: 1.1rem;
    opacity: 0.9;
    line-height: 1.8;
    margin-bottom: 2rem;
}

.hero-image {
    display: flex;
    justify-content: center;
}

.profile-photo {
    width: 320px;
    height: 320px;
    border-radius: 50%;
    object-fit: cover;
    border: 4px solid rgba(255, 255, 255, 0.3);
    box-shadow: var(--shadow-lg);
}

.hero-links {
    display: flex;
    gap: 1.5rem;
    margin-bottom: 1.5rem;
}

.hero-links a {
    color: rgba(255, 255, 255, 0.9);
    font-size: 0.95rem;
    border-bottom: 1px solid rgba(255, 255, 255, 0.4);
    padding-bottom: 2px;
    transition: all 0.2s;
}

.hero-links a:hover {
    color: white;
    border-bottom-color: white;
}

.hero-buttons {
    display: flex;
    flex-wrap: wrap;
    gap: 1rem;
}

.btn {
    display: inline-block;
    padding: 0.875rem 2rem;
    border-radius: 8px;
    font-weight: 600;
    transition: all 0.2s;
    cursor: pointer;
    border: none;
    font-size: 1rem;
}

.btn-primary {
    background: var(--accent);
    color: white;
}

.btn-primary:hover {
    background: var(--accent-light);
    transform: translateY(-2px);
    box-shadow: var(--shadow-lg);
}

.btn-secondary {
    background: transparent;
    color: white;
    border: 2px solid rgba(255, 255, 255, 0.5);
}

.btn-secondary:hover {
    border-color: white;
    background: rgba(255, 255, 255, 0.1);
}

/* Sections */
.section {
    padding: 6rem 2rem;
}

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

.section-container {
    max-width: 1000px;
    margin: 0 auto;
}

.section-header {
    text-align: center;
    margin-bottom: 4rem;
}

.section-header h2 {
    font-size: 2.5rem;
    font-weight: 700;
    color: var(--primary);
    margin-bottom: 1rem;
    position: relative;
    display: inline-block;
}

.section-header h2::after {
    content: '';
    position: absolute;
    bottom: -10px;
    left: 50%;
    transform: translateX(-50%);
    width: 60px;
    height: 4px;
    background: var(--accent);
    border-radius: 2px;
}

.section-header p {
    color: var(--text-muted);
    font-size: 1.1rem;
    max-width: 600px;
    margin: 1.5rem auto 0;
}

/* Research Cards */
.research-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
    gap: 2rem;
}

.research-card {
    background: white;
    border-radius: 12px;
    padding: 2rem;
    box-shadow: var(--shadow);
    transition: all 0.3s;
    border-left: 4px solid var(--accent);
}

.research-card:hover {
    transform: translateY(-4px);
    box-shadow: var(--shadow-lg);
}

.research-card h3 {
    font-size: 1.25rem;
    color: var(--primary);
    margin-bottom: 1rem;
}

.research-card p {
    color: var(--text-light);
    font-size: 0.95rem;
    line-height: 1.7;
}

/* Publications */
.publications-list {
    display: flex;
    flex-direction: column;
    gap: 1.5rem;
}

.publication-item {
    background: white;
    border-radius: 12px;
    padding: 1.5rem 2rem;
    box-shadow: var(--shadow);
    transition: all 0.3s;
}

.publication-item:hover {
    box-shadow: var(--shadow-lg);
}

.publication-item.featured {
    background: linear-gradient(135deg, var(--primary) 0%, var(--primary-light) 100%);
    color: white;
    border-left: 4px solid var(--accent);
}

.publication-item.featured .year {
    background: var(--accent);
}

.publication-item.featured h4 {
    color: white;
}

.publication-item.featured .authors {
    color: rgba(255, 255, 255, 0.9);
}

.publication-item.featured .journal {
    color: rgba(255, 255, 255, 0.8);
}

.publication-item .year {
    display: inline-block;
    background: var(--accent);
    color: white;
    padding: 0.25rem 0.75rem;
    border-radius: 20px;
    font-size: 0.85rem;
    font-weight: 600;
    margin-bottom: 0.75rem;
}

.publication-item h4 {
    font-size: 1.1rem;
    color: var(--primary);
    margin-bottom: 0.5rem;
    line-height: 1.4;
}

.publication-item .authors {
    color: var(--text-light);
    font-size: 0.95rem;
    margin-bottom: 0.25rem;
}

.publication-item .journal {
    color: var(--text-muted);
    font-style: italic;
    font-size: 0.9rem;
}

/* Teaching */
.teaching-list {
    display: flex;
    flex-direction: column;
    gap: 1.5rem;
}

.teaching-item {
    background: white;
    border-radius: 12px;
    padding: 2rem;
    box-shadow: var(--shadow);
    display: grid;
    grid-template-columns: auto 1fr;
    gap: 1.5rem;
    align-items: start;
}

.teaching-item .semester {
    background: var(--primary);
    color: white;
    padding: 0.5rem 1rem;
    border-radius: 8px;
    font-weight: 600;
    font-size: 0.9rem;
    white-space: nowrap;
}

.teaching-item h4 {
    font-size: 1.15rem;
    color: var(--primary);
    margin-bottom: 0.5rem;
}

.teaching-item p {
    color: var(--text-light);
    font-size: 0.95rem;
    line-height: 1.6;
}

/* CV Section */
.cv-content {
    background: white;
    border-radius: 12px;
    padding: 3rem;
    box-shadow: var(--shadow);
}

.cv-section {
    margin-bottom: 2.5rem;
}

.cv-section:last-child {
    margin-bottom: 0;
}

.cv-section h3 {
    font-size: 1.25rem;
    color: var(--primary);
    margin-bottom: 1.5rem;
    padding-bottom: 0.75rem;
    border-bottom: 2px solid var(--border);
}

.cv-item {
    display: grid;
    grid-template-columns: 150px 1fr;
    gap: 1.5rem;
    margin-bottom: 1.25rem;
}

.cv-item .date {
    color: var(--text-muted);
    font-size: 0.9rem;
    font-weight: 500;
}

.cv-item .details h4 {
    font-size: 1rem;
    color: var(--text);
    margin-bottom: 0.25rem;
}

.cv-item .details p {
    color: var(--text-light);
    font-size: 0.95rem;
}

.cv-download {
    text-align: center;
    margin-top: 2rem;
    padding-top: 2rem;
    border-top: 1px solid var(--border);
}

/* Contact Section */
.contact-container {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 3rem;
}

.contact-container.contact-single {
    grid-template-columns: 1fr;
    max-width: 500px;
    margin: 0 auto;
}

.contact-info {
    background: white;
    border-radius: 12px;
    padding: 2.5rem;
    box-shadow: var(--shadow);
}

.contact-info h3 {
    font-size: 1.5rem;
    color: var(--primary);
    margin-bottom: 2rem;
}

.contact-item {
    display: flex;
    align-items: flex-start;
    gap: 1rem;
    margin-bottom: 1.5rem;
}

.contact-item .icon {
    width: 40px;
    height: 40px;
    background: var(--accent);
    border-radius: 8px;
    display: flex;
    align-items: center;
    justify-content: center;
    color: white;
    font-size: 1.2rem;
    flex-shrink: 0;
    font-weight: bold;
}

.contact-item .content h4 {
    font-size: 0.9rem;
    color: var(--text-muted);
    margin-bottom: 0.25rem;
    text-transform: uppercase;
    letter-spacing: 0.5px;
}

.contact-item .content p {
    color: var(--text);
    font-size: 1rem;
}

.contact-form {
    background: white;
    border-radius: 12px;
    padding: 2.5rem;
    box-shadow: var(--shadow);
}

.contact-form h3 {
    font-size: 1.5rem;
    color: var(--primary);
    margin-bottom: 2rem;
}

.form-group {
    margin-bottom: 1.25rem;
}

.form-group label {
    display: block;
    font-size: 0.9rem;
    color: var(--text-light);
    margin-bottom: 0.5rem;
    font-weight: 500;
}

.form-group input,
.form-group textarea {
    width: 100%;
    padding: 0.875rem 1rem;
    border: 2px solid var(--border);
    border-radius: 8px;
    font-size: 1rem;
    transition: border-color 0.2s;
    font-family: inherit;
}

.form-group input:focus,
.form-group textarea:focus {
    outline: none;
    border-color: var(--primary);
}

.form-group textarea {
    min-height: 120px;
    resize: vertical;
}

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

.footer p {
    opacity: 0.8;
    font-size: 0.95rem;
}

.footer-links {
    margin-top: 1rem;
    display: flex;
    justify-content: center;
    gap: 2rem;
}

.footer-links a {
    color: white;
    opacity: 0.8;
    transition: opacity 0.2s;
}

.footer-links a:hover {
    opacity: 1;
}

/* Responsive */
@media (max-width: 968px) {
    .hero-container {
        grid-template-columns: 1fr;
        text-align: center;
    }

    .hero-content h1 {
        font-size: 2.5rem;
    }

    .hero-image {
        order: -1;
    }

    .profile-photo {
        width: 250px;
        height: 250px;
    }

    .hero-buttons {
        justify-content: center;
    }

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

    .cv-item {
        grid-template-columns: 1fr;
        gap: 0.5rem;
    }

    .teaching-item {
        grid-template-columns: 1fr;
    }
}

@media (max-width: 640px) {
    .nav-links {
        display: none;
    }

    .hero {
        padding: 6rem 1.5rem 3rem;
    }

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

    .section {
        padding: 4rem 1.5rem;
    }

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