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

:root {
    --primary-color: #2563eb;
    --secondary-color: #1e40af;
    --text-dark: #1f2937;
    --text-light: #6b7280;
    --bg-light: #f9fafb;
    --bg-white: #ffffff;
    --border-color: #e5e7eb;
    --accent-color: #3b82f6;
    --success-color: #10b981;
    --shadow-sm: 0 1px 2px 0 rgba(0, 0, 0, 0.05);
    --shadow-md: 0 4px 6px -1px rgba(0, 0, 0, 0.1);
    --shadow-lg: 0 10px 15px -3px rgba(0, 0, 0, 0.1);
    --transition: all 0.3s ease;
}

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

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

/* Navigation */
.navbar {
    background: var(--bg-white);
    box-shadow: var(--shadow-sm);
    position: sticky;
    top: 0;
    z-index: 1000;
    border-bottom: 1px solid var(--border-color);
}

.navbar .container {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 1rem 2rem;
}

.logo {
    font-size: 1.5rem;
    font-weight: 700;
    color: var(--text-dark);
    text-decoration: none;
    transition: var(--transition);
}

.logo:hover {
    color: var(--primary-color);
}

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

.nav-links a {
    color: var(--text-light);
    text-decoration: none;
    font-weight: 500;
    transition: var(--transition);
    position: relative;
}

.nav-links a:hover,
.nav-links a.active {
    color: var(--primary-color);
}

.nav-links a.active::after {
    content: '';
    position: absolute;
    bottom: -0.5rem;
    left: 0;
    right: 0;
    height: 2px;
    background: var(--primary-color);
}

/* Hero Section */
.hero {
    padding: 4rem 0;
    background: linear-gradient(135deg, #2c3e50 0%, #3498db 100%);
    color: white;
}

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

.hero h1 {
    font-size: 2.5rem;
    margin-bottom: 0.5rem;
    line-height: 1.2;
}

.highlight {
    color: #fbbf24;
}

.subtitle {
    font-size: 1.5rem;
    font-weight: 600;
    margin-bottom: 0.5rem;
    opacity: 0.95;
}

.bio {
    font-size: 1.1rem;
    margin-bottom: 1.5rem;
    opacity: 0.9;
}

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

.social-btn {
    display: flex;
    align-items: center;
    justify-content: center;
    width: 40px;
    height: 40px;
    background: rgba(255, 255, 255, 0.2);
    border-radius: 50%;
    color: white;
    text-decoration: none;
    transition: var(--transition);
    backdrop-filter: blur(10px);
}

.social-btn:hover {
    background: rgba(255, 255, 255, 0.3);
    transform: translateY(-2px);
}

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

.hero-image img {
    width: 100%;
    max-width: 300px;
    border-radius: 20px;
    box-shadow: var(--shadow-lg);
    border: 4px solid rgba(255, 255, 255, 0.2);
}

/* About Section */
.about {
    padding: 4rem 0;
    background: var(--bg-light);
}

.about h2 {
    font-size: 2rem;
    margin-bottom: 2rem;
    text-align: center;
    color: var(--text-dark);
}

.content-card {
    background: var(--bg-white);
    padding: 2.5rem;
    border-radius: 12px;
    box-shadow: var(--shadow-md);
    max-width: 900px;
    margin: 0 auto;
}

.content-card p {
    margin-bottom: 1.5rem;
    color: var(--text-dark);
    line-height: 1.8;
}

.content-card a {
    color: var(--primary-color);
    text-decoration: none;
    font-weight: 500;
    transition: var(--transition);
}

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

/* Publications Section */
.featured-publications {
    padding: 4rem 0;
    background: var(--bg-white);
}

.featured-publications h2 {
    font-size: 2rem;
    margin-bottom: 2rem;
    text-align: center;
    color: var(--text-dark);
}

.publication-card {
    display: grid;
    grid-template-columns: 300px 1fr;
    gap: 2rem;
    background: var(--bg-white);
    padding: 2rem;
    border-radius: 12px;
    box-shadow: var(--shadow-md);
    margin-bottom: 2rem;
    transition: var(--transition);
    border: 1px solid var(--border-color);
}

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

.pub-image img {
    width: 100%;
    border-radius: 8px;
    object-fit: cover;
}

.pub-content h3 {
    font-size: 1.3rem;
    margin-bottom: 1rem;
    color: var(--text-dark);
    line-height: 1.4;
}

.authors {
    font-size: 0.95rem;
    color: var(--text-light);
    margin-bottom: 0.5rem;
    line-height: 1.6;
}

.authors .me {
    font-weight: 700;
    color: var(--text-dark);
}

.authors .equal {
    color: var(--text-dark);
}

.footnote {
    font-size: 0.85rem;
    color: var(--text-light);
    font-style: italic;
    margin-bottom: 1rem;
}

.btn-primary,
.btn-secondary {
    display: inline-block;
    padding: 0.75rem 1.5rem;
    border-radius: 8px;
    text-decoration: none;
    font-weight: 600;
    transition: var(--transition);
    border: none;
    cursor: pointer;
}

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

.btn-primary:hover {
    background: var(--secondary-color);
    transform: translateY(-2px);
    box-shadow: var(--shadow-md);
}

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

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

/* Blog Section */
.blog-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(350px, 1fr));
    gap: 2rem;
    margin-top: 2rem;
}

.blog-card {
    background: var(--bg-white);
    border-radius: 12px;
    overflow: hidden;
    box-shadow: var(--shadow-md);
    transition: var(--transition);
    border: 1px solid var(--border-color);
}

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

.blog-card-content {
    padding: 1.5rem;
}

.blog-card h3 {
    font-size: 1.25rem;
    margin-bottom: 0.5rem;
    color: var(--text-dark);
}

.blog-meta {
    font-size: 0.875rem;
    color: var(--text-light);
    margin-bottom: 1rem;
}

.blog-tag {
    display: inline-block;
    background: var(--bg-light);
    padding: 0.25rem 0.75rem;
    border-radius: 20px;
    font-size: 0.75rem;
    color: var(--text-dark);
    margin-right: 0.5rem;
    margin-top: 0.5rem;
}

.blog-card p {
    color: var(--text-light);
    line-height: 1.6;
}

.blog-card a {
    text-decoration: none;
    color: inherit;
}

/* CV Section */
.cv-section {
    padding: 4rem 0;
    background: var(--bg-light);
}

.cv-header {
    text-align: center;
    margin-bottom: 3rem;
}

.cv-header h1 {
    font-size: 2.5rem;
    margin-bottom: 1rem;
}

.cv-download {
    margin-top: 1rem;
}

.cv-content {
    background: var(--bg-white);
    padding: 3rem;
    border-radius: 12px;
    box-shadow: var(--shadow-md);
    max-width: 900px;
    margin: 0 auto;
}

.cv-content h2 {
    font-size: 1.75rem;
    color: var(--primary-color);
    margin-top: 2rem;
    margin-bottom: 1rem;
    padding-bottom: 0.5rem;
    border-bottom: 2px solid var(--border-color);
}

.cv-content h3 {
    font-size: 1.25rem;
    color: var(--text-dark);
    margin-top: 1.5rem;
    margin-bottom: 0.5rem;
}

.cv-item {
    margin-bottom: 2rem;
}

.cv-item-header {
    display: flex;
    justify-content: space-between;
    align-items: start;
    margin-bottom: 0.5rem;
}

.cv-item-title {
    font-weight: 700;
    color: var(--text-dark);
    font-size: 1.1rem;
}

.cv-item-date {
    color: var(--text-light);
    font-style: italic;
    white-space: nowrap;
}

.cv-item-subtitle {
    color: var(--text-light);
    margin-bottom: 0.5rem;
}

.cv-content ul {
    margin-left: 1.5rem;
    margin-bottom: 1rem;
}

.cv-content li {
    margin-bottom: 0.5rem;
    color: var(--text-dark);
}

.cv-content a {
    color: var(--primary-color);
    text-decoration: none;
}

.cv-content a:hover {
    text-decoration: underline;
}

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

footer p {
    margin: 0.25rem 0;
    opacity: 0.8;
}

/* Responsive Design */
@media (max-width: 768px) {
    .container {
        padding: 0 1rem;
    }

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

    .nav-links {
        gap: 1rem;
    }

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

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

    .subtitle {
        font-size: 1.25rem;
    }

    .publication-card {
        grid-template-columns: 1fr;
    }

    .blog-grid {
        grid-template-columns: 1fr;
    }

    .cv-item-header {
        flex-direction: column;
    }

    .cv-item-date {
        white-space: normal;
    }
}

/* Page Header */
.page-header {
    background: linear-gradient(135deg, #2c3e50 0%, #3498db 100%);
    color: white;
    padding: 3rem 0;
    text-align: center;
}

.page-header h1 {
    font-size: 2.5rem;
    margin-bottom: 0.5rem;
}

.page-header p {
    font-size: 1.1rem;
    opacity: 0.9;
}

/* Content Section */
.content-section {
    padding: 4rem 0;
    background: var(--bg-light);
}

/* Animations */
@keyframes fadeIn {
    from {
        opacity: 0;
        transform: translateY(20px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

.fade-in {
    animation: fadeIn 0.6s ease-out;
}

/* Utility Classes */
.text-center {
    text-align: center;
}

.mt-1 { margin-top: 0.5rem; }
.mt-2 { margin-top: 1rem; }
.mt-3 { margin-top: 1.5rem; }
.mt-4 { margin-top: 2rem; }

.mb-1 { margin-bottom: 0.5rem; }
.mb-2 { margin-bottom: 1rem; }
.mb-3 { margin-bottom: 1.5rem; }
.mb-4 { margin-bottom: 2rem; }