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

html {
    scroll-behavior: smooth;
    font-size: 16px;
}

body {
    font-family: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, Oxygen, Ubuntu, Cantarell, sans-serif;
    line-height: 1.6;
    color: #1f2937;
    background-color: #ffffff;
}

/* CSS Variables */
:root {
    --primary-color: #1e3a8a;
    --secondary-color: #2563eb;
    --accent-color: #d97706;
    --text-primary: #1f2937;
    --text-secondary: #6b7280;
    --text-light: #9ca3af;
    --bg-light: #f9fafb;
    --bg-dark: #1f2937;
    --white: #ffffff;
    --border-color: #e5e7eb;
    --shadow: 0 4px 6px -1px rgba(0, 0, 0, 0.1);
    --shadow-lg: 0 10px 15px -3px rgba(0, 0, 0, 0.1);
    --border-radius: 8px;
    --transition: all 0.3s ease;
}

/* Typography */
h1, h2, h3, h4, h5, h6 {
    font-family: 'Playfair Display', serif;
    font-weight: 600;
    line-height: 1.2;
    color: var(--text-primary);
}

h1 { font-size: 3.5rem; }
h2 { font-size: 2.5rem; }
h3 { font-size: 1.875rem; }
h4 { font-size: 1.5rem; }
h5 { font-size: 1.25rem; }
h6 { font-size: 1.125rem; }

p {
    margin-bottom: 1rem;
    color: var(--text-secondary);
}

a {
    text-decoration: none;
    color: var(--primary-color);
    transition: var(--transition);
}

a:hover {
    color: var(--secondary-color);
}

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

.section-padding {
    padding: 5rem 0;
}

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

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

.text-white {
    color: var(--white);
}

/* Section Headers */
.section-header {
    text-align: center;
    margin-bottom: 4rem;
}

.section-title {
    margin-bottom: 1rem;
    color: var(--text-primary);
}

.section-subtitle {
    font-size: 1.125rem;
    color: var(--text-secondary);
    max-width: 600px;
    margin: 0 auto;
}

/* Buttons */
.btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    padding: 0.75rem 2rem;
    border: none;
    border-radius: var(--border-radius);
    font-size: 1rem;
    font-weight: 500;
    text-decoration: none;
    cursor: pointer;
    transition: var(--transition);
    min-width: 140px;
}

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

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

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

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

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

.btn-outline:hover {
    background-color: var(--accent-color);
    color: var(--white);
    transform: translateY(-2px);
}

/* Header & Navigation */
.header {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    background-color: rgba(255, 255, 255, 0.95);
    backdrop-filter: blur(10px);
    border-bottom: 1px solid var(--border-color);
    z-index: 1000;
    transition: var(--transition);
}

.header.scrolled {
    background-color: rgba(255, 255, 255, 0.98);
    box-shadow: var(--shadow);
}

.navbar {
    padding: 1rem 0;
}

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

.nav-logo h2 {
    font-size: 1.5rem;
    color: var(--primary-color);
    margin: 0;
}

.nav-menu {
    display: flex;
    list-style: none;
    gap: 2rem;
    margin: 0;
}

.nav-link {
    color: var(--text-primary);
    font-weight: 500;
    padding: 0.5rem 0;
    position: relative;
}

.nav-link::after {
    content: '';
    position: absolute;
    bottom: -2px;
    left: 0;
    width: 0;
    height: 2px;
    background-color: var(--accent-color);
    transition: var(--transition);
}

.nav-link:hover::after,
.nav-link.active::after {
    width: 100%;
}

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

/* Hamburger Menu */
.hamburger {
    display: none;
    flex-direction: column;
    cursor: pointer;
    gap: 4px;
}

.bar {
    width: 25px;
    height: 3px;
    background-color: var(--text-primary);
    transition: var(--transition);
}

/* Hero Section */
.hero {
    padding: 8rem 0 6rem;
    background: linear-gradient(135deg, #f8fafc 0%, #e2e8f0 100%);
}

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

.hero-content {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 4rem;
    align-items: center;
}

.hero-title {
    font-size: 3.5rem;
    margin-bottom: 1rem;
    color: var(--text-primary);
}

.hero-degree {
    color: var(--accent-color);
}

.hero-subtitle {
    font-size: 1.5rem;
    color: var(--primary-color);
    margin-bottom: 0.5rem;
    font-weight: 500;
}

.hero-institution {
    font-size: 1.125rem;
    color: var(--text-secondary);
    margin-bottom: 1.5rem;
}

.hero-description {
    font-size: 1.125rem;
    color: var(--text-secondary);
    margin-bottom: 2rem;
    line-height: 1.7;
}

.hero-stats {
    display: flex;
    gap: 2rem;
    margin-bottom: 2.5rem;
}

.stat {
    text-align: center;
}

.stat-number {
    display: block;
    font-size: 2rem;
    font-weight: 700;
    color: var(--accent-color);
    font-family: 'Inter', sans-serif;
}

.stat-label {
    font-size: 0.875rem;
    color: var(--text-light);
    text-transform: uppercase;
    letter-spacing: 0.5px;
}

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

.hero-image {
    position: relative;
}

.image-placeholder {
    position: relative;
    border-radius: 12px;
    overflow: hidden;
    box-shadow: var(--shadow-lg);
}

.hero-img {
    width: 100%;
    height: auto;
    border-radius: 12px;
}

/* About Section */
.about-content {
    display: grid;
    grid-template-columns: 1fr 400px;
    gap: 4rem;
    align-items: start;
}

.about-intro {
    font-size: 1.125rem;
    color: var(--text-primary);
    margin-bottom: 2rem;
    line-height: 1.7;
}

.about-details {
    display: flex;
    flex-direction: column;
    gap: 2rem;
}

.about-item h3 {
    color: var(--primary-color);
    margin-bottom: 0.75rem;
}

.about-item p {
    line-height: 1.7;
}

.about-image {
    position: relative;
}

.about-img {
    width: 100%;
    height: auto;
    border-radius: 12px;
    box-shadow: var(--shadow);
}

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

.research-card {
    background: var(--white);
    padding: 2rem;
    border-radius: 12px;
    box-shadow: var(--shadow);
    text-align: center;
    transition: var(--transition);
}

.research-card:hover {
    transform: translateY(-5px);
    box-shadow: var(--shadow-lg);
}

.research-icon {
    width: 80px;
    height: 80px;
    margin: 0 auto 1.5rem;
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    background-color: var(--bg-light);
}

.research-icon img {
    border-radius: 50%;
}

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

.research-card p {
    line-height: 1.6;
}

/* Publications Section */
.publications-content {
    display: grid;
    grid-template-columns: 1fr;
    gap: 3rem;
}

.publications-stats {
    display: flex;
    justify-content: center;
    gap: 3rem;
    margin-bottom: 2rem;
}

.pub-stat {
    text-align: center;
    padding: 1.5rem;
    background: var(--white);
    border-radius: 12px;
    box-shadow: var(--shadow);
    min-width: 150px;
}

.pub-stat h3 {
    font-size: 2.5rem;
    color: var(--accent-color);
    margin-bottom: 0.5rem;
    font-family: 'Inter', sans-serif;
}

.publications-links {
    text-align: center;
    margin-bottom: 2rem;
}

.publications-links h3 {
    margin-bottom: 1.5rem;
    color: var(--primary-color);
}

.pub-buttons {
    display: flex;
    justify-content: center;
    gap: 1rem;
    flex-wrap: wrap;
}

.recent-publications {
    background: var(--white);
    padding: 2rem;
    border-radius: 12px;
    box-shadow: var(--shadow);
}

.recent-publications h3 {
    color: var(--primary-color);
    margin-bottom: 1.5rem;
}

.pub-list {
    display: flex;
    flex-direction: column;
    gap: 1.5rem;
}

.pub-item {
    padding: 1.5rem;
    border: 1px solid var(--border-color);
    border-radius: var(--border-radius);
    background: var(--bg-light);
}

.pub-item h4 {
    color: var(--primary-color);
    margin-bottom: 0.5rem;
    font-size: 1.125rem;
}

.pub-authors {
    font-style: italic;
    color: var(--text-secondary);
    margin-bottom: 0.25rem;
}

.pub-journal {
    color: var(--text-light);
    font-size: 0.875rem;
    margin-bottom: 0.75rem;
}

.pub-link {
    color: var(--accent-color);
    font-weight: 500;
    text-decoration: underline;
}

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

/* Expertise Section */
.expertise {
    background-color: var(--bg-light);
}

.expertise-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: 2rem;
    margin-top: 3rem;
}

.expertise-category {
    background: var(--white);
    padding: 2rem;
    border-radius: var(--border-radius);
    box-shadow: var(--shadow-sm);
    transition: var(--transition);
}

.expertise-category:hover {
    transform: translateY(-5px);
    box-shadow: var(--shadow-lg);
}

.expertise-category h3 {
    color: var(--primary-color);
    margin-bottom: 1.5rem;
    font-size: 1.25rem;
    border-bottom: 2px solid var(--accent-color);
    padding-bottom: 0.5rem;
}

.expertise-list {
    list-style: none;
    padding: 0;
}

.expertise-list li {
    padding: 0.5rem 0;
    line-height: 1.6;
    color: var(--text-color);
    border-bottom: 1px solid #f3f4f6;
}

.expertise-list li:last-child {
    border-bottom: none;
}

.expertise-list strong {
    color: var(--heading-color);
    font-weight: 600;
}

/* Services Section */
.services-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: 2rem;
}

.service-card {
    background: var(--white);
    padding: 2rem;
    border-radius: 12px;
    box-shadow: var(--shadow);
    transition: var(--transition);
}

.service-card:hover {
    transform: translateY(-5px);
    box-shadow: var(--shadow-lg);
}

.service-icon {
    width: 60px;
    height: 60px;
    margin-bottom: 1.5rem;
    display: flex;
    align-items: center;
    justify-content: center;
    background: var(--bg-light);
    border-radius: 50%;
}

.service-card h3 {
    color: var(--primary-color);
    margin-bottom: 1rem;
}

.service-card p {
    margin-bottom: 1.5rem;
    line-height: 1.6;
}

.service-features {
    list-style: none;
}

.service-features li {
    position: relative;
    padding-left: 1.5rem;
    margin-bottom: 0.5rem;
    color: var(--text-secondary);
}

.service-features li::before {
    content: '✓';
    position: absolute;
    left: 0;
    color: var(--accent-color);
    font-weight: bold;
}

/* Awards Section */
.awards-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: 2rem;
}

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

.award-card.featured {
    border-left-color: var(--primary-color);
    background: linear-gradient(135deg, #fef3c7 0%, #fef9e7 100%);
}

.award-card:hover {
    transform: translateY(-3px);
    box-shadow: var(--shadow-lg);
}

.award-year {
    display: inline-block;
    background: var(--accent-color);
    color: var(--white);
    padding: 0.5rem 1rem;
    border-radius: 20px;
    font-size: 0.875rem;
    font-weight: 600;
    margin-bottom: 1rem;
}

.award-card.featured .award-year {
    background: var(--primary-color);
}

.award-content h3 {
    color: var(--primary-color);
    margin-bottom: 0.75rem;
}

.award-content p {
    line-height: 1.6;
}


/* Contact Section */
.contact-content {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 4rem;
}

.contact-info {
    display: flex;
    flex-direction: column;
    gap: 2rem;
}

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

.contact-icon {
    width: 40px;
    height: 40px;
    background: var(--accent-color);
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    flex-shrink: 0;
}

.contact-details h3 {
    color: var(--white);
    margin-bottom: 0.5rem;
}

.contact-details p,
.contact-details a {
    color: #d1d5db;
}

.contact-details a:hover {
    color: var(--white);
}

/* Contact Form */
.contact-form {
    background: rgba(255, 255, 255, 0.1);
    padding: 2rem;
    border-radius: 12px;
    backdrop-filter: blur(10px);
    border: 1px solid rgba(255, 255, 255, 0.2);
}

.form-group {
    margin-bottom: 1.5rem;
}

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

.form-group input,
.form-group select,
.form-group textarea {
    width: 100%;
    padding: 0.75rem;
    border: 1px solid rgba(255, 255, 255, 0.3);
    border-radius: var(--border-radius);
    background: rgba(255, 255, 255, 0.1);
    color: var(--white);
    backdrop-filter: blur(5px);
    transition: var(--transition);
}

/* Fix dropdown option visibility */
.form-group select option {
    background: #1f2937;
    color: var(--white);
}

.form-group select:focus option {
    background: #1f2937;
    color: var(--white);
}

.form-group select option:hover,
.form-group select option:checked {
    background: var(--primary-color);
    color: var(--white);
}

.form-group input::placeholder,
.form-group textarea::placeholder {
    color: #9ca3af;
}

.form-group input:focus,
.form-group select:focus,
.form-group textarea:focus {
    outline: none;
    border-color: var(--accent-color);
    box-shadow: 0 0 0 3px rgba(217, 119, 6, 0.1);
}

/* Footer */
.footer {
    background-color: #111827;
    color: var(--white);
    padding: 3rem 0 1rem;
}

.footer-content {
    display: grid;
    grid-template-columns: 1fr 2fr;
    gap: 3rem;
    margin-bottom: 2rem;
}

.footer-info h3 {
    color: var(--white);
    margin-bottom: 1rem;
}

.footer-info p {
    color: #9ca3af;
}

.footer-links {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 2rem;
}

.footer-section h4 {
    color: var(--white);
    margin-bottom: 1rem;
    font-size: 1.125rem;
}

.footer-section ul {
    list-style: none;
}

.footer-section ul li {
    margin-bottom: 0.5rem;
}

.footer-section ul li a {
    color: #9ca3af;
    transition: var(--transition);
}

.footer-section ul li a:hover {
    color: var(--accent-color);
}

.footer-bottom {
    padding-top: 2rem;
    border-top: 1px solid #374151;
    text-align: center;
    color: #6b7280;
}

.footer-bottom p {
    margin-bottom: 0.5rem;
}

/* Responsive Design */
@media (max-width: 1024px) {
    .container {
        padding: 0 1.5rem;
    }
    
    .nav-container {
        padding: 0 1.5rem;
    }
    
    .hero-content {
        grid-template-columns: 1fr;
        gap: 3rem;
        text-align: center;
    }
    
    .hero-title {
        font-size: 3rem;
    }
    
    .about-content {
        grid-template-columns: 1fr;
        gap: 3rem;
    }
    
    .about-image {
        order: -1;
    }
    
    .contact-content {
        grid-template-columns: 1fr;
        gap: 3rem;
    }
    
    .footer-content {
        grid-template-columns: 1fr;
        gap: 2rem;
    }
    
    .footer-links {
        grid-template-columns: repeat(2, 1fr);
    }
}

@media (max-width: 768px) {
    html {
        font-size: 14px;
    }
    
    .section-padding {
        padding: 3rem 0;
    }
    
    .container {
        padding: 0 1rem;
    }
    
    .nav-container {
        padding: 0 1rem;
    }
    
    /* Mobile Navigation */
    .nav-menu {
        position: fixed;
        top: 70px;
        left: -100%;
        width: 100%;
        height: calc(100vh - 70px);
        background-color: var(--white);
        flex-direction: column;
        justify-content: flex-start;
        align-items: center;
        padding-top: 2rem;
        gap: 1rem;
        transition: var(--transition);
        box-shadow: var(--shadow);
    }
    
    .nav-menu.active {
        left: 0;
    }
    
    .hamburger {
        display: flex;
    }
    
    .hamburger.active .bar:nth-child(2) {
        opacity: 0;
    }
    
    .hamburger.active .bar:nth-child(1) {
        transform: translateY(7px) rotate(45deg);
    }
    
    .hamburger.active .bar:nth-child(3) {
        transform: translateY(-7px) rotate(-45deg);
    }
    
    /* Hero Responsive */
    .hero {
        padding: 6rem 0 4rem;
    }
    
    .hero-title {
        font-size: 2.5rem;
    }
    
    .hero-stats {
        justify-content: center;
        gap: 1.5rem;
    }
    
    .hero-buttons {
        justify-content: center;
    }
    
    /* Publications Stats */
    .publications-stats {
        flex-direction: column;
        align-items: center;
        gap: 1.5rem;
    }
    
    .pub-stat {
        min-width: 120px;
    }
    
    /* Services Grid */
    .services-grid {
        grid-template-columns: 1fr;
    }
    
    /* Awards Grid */
    .awards-grid {
        grid-template-columns: 1fr;
    }
    
    /* Footer */
    .footer-links {
        grid-template-columns: 1fr;
        text-align: center;
    }
}

@media (max-width: 480px) {
    .hero-title {
        font-size: 2rem;
    }
    
    .section-title {
        font-size: 2rem;
    }
    
    .btn {
        width: 100%;
        margin-bottom: 0.5rem;
    }
    
    .hero-buttons {
        flex-direction: column;
        align-items: center;
    }
    
    .pub-buttons {
        flex-direction: column;
        align-items: center;
        max-width: 300px;
        margin: 0 auto;
    }
    
    .research-grid,
    .services-grid,
    .awards-grid {
        grid-template-columns: 1fr;
        gap: 1.5rem;
    }
}

/* Animations and Transitions */
@keyframes fadeInUp {
    from {
        opacity: 0;
        transform: translateY(30px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

.section-header {
    animation: fadeInUp 0.6s ease-out;
}

/* Smooth scrolling offset for fixed header */
section {
    scroll-margin-top: 80px;
}

/* Focus styles for accessibility */
.btn:focus,
input:focus,
select:focus,
textarea:focus {
    outline: 2px solid var(--accent-color);
    outline-offset: 2px;
}

/* Print styles */
@media print {
    .header,
    .hamburger,
    .hero-buttons,
    .contact-form,
    .footer {
        display: none;
    }
    
    .hero {
        padding: 2rem 0;
    }
    
    .section-padding {
        padding: 2rem 0;
    }
}