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

:root {
    --primary-color: #1e40af;
    --secondary-color: #3b82f6;
    --accent-color: #60a5fa;
    --text-dark: #1f2937;
    --text-light: #6b7280;
    --bg-light: #f9fafb;
    --white: #ffffff;
    --shadow: 0 4px 6px rgba(0, 0, 0, 0.1);
    --shadow-lg: 0 10px 25px rgba(0, 0, 0, 0.15);
}

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(--white);
}

html {
    scroll-behavior: smooth;
}

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

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

/* Container */
.container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 20px;
}

/* Navigation */
.navbar {
    background: var(--white);
    box-shadow: var(--shadow);
    position: fixed;
    width: 100%;
    top: 0;
    z-index: 1000;
    padding: 1rem 0;
}

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

.nav-brand {
    font-size: 1.5rem;
    font-weight: 700;
    color: var(--primary-color);
}

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

.nav-menu a {
    color: var(--text-dark);
    font-weight: 500;
    padding: 0.5rem 0;
    border-bottom: 2px solid transparent;
    transition: all 0.3s ease;
}

.nav-menu a:hover {
    color: var(--primary-color);
    border-bottom-color: var(--primary-color);
}

/* Hero Section */
.hero {
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    color: var(--white);
    padding: 120px 0 60px;
    margin-top: 60px;
}

.hero-content {
    display: flex;
    align-items: center;
    gap: 3rem;
}

.hero-avatar {
    width: 180px;
    height: 180px;
    border-radius: 50%;
    background: rgba(255, 255, 255, 0.2);
    backdrop-filter: blur(10px);
    display: flex;
    align-items: center;
    justify-content: center;
    border: 4px solid rgba(255, 255, 255, 0.3);
    flex-shrink: 0;
    overflow: hidden;
}

.hero-avatar img {
    width: 100%;
    height: 100%;
    object-fit: cover;
    object-position: center;
}

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

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

.institution {
    font-size: 1.1rem;
    margin-bottom: 0.5rem;
    opacity: 0.9;
}

.supervisor {
    font-size: 1rem;
    margin-bottom: 1.5rem;
    opacity: 0.85;
}

.hero-links {
    display: flex;
    flex-wrap: wrap;
    gap: 1rem;
    margin-top: 1.5rem;
}

.hero-links a {
    background: rgba(255, 255, 255, 0.2);
    backdrop-filter: blur(10px);
    color: var(--white);
    padding: 0.6rem 1.2rem;
    border-radius: 8px;
    border: 1px solid rgba(255, 255, 255, 0.3);
    font-weight: 500;
    transition: all 0.3s ease;
}

.hero-links a:hover {
    background: rgba(255, 255, 255, 0.3);
    transform: translateY(-2px);
}

/* Section Styles */
.section {
    padding: 80px 0;
}

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

.section-title {
    font-size: 2.5rem;
    color: var(--primary-color);
    margin-bottom: 2rem;
    font-weight: 700;
    border-bottom: 3px solid var(--accent-color);
    padding-bottom: 0.5rem;
    display: inline-block;
}

/* Card Styles */
.card {
    background: var(--white);
    border-radius: 12px;
    padding: 2rem;
    box-shadow: var(--shadow);
    margin-bottom: 2rem;
}

.card p {
    margin-bottom: 1rem;
    color: var(--text-light);
    font-size: 1.1rem;
}

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

.interest-box {
    background: linear-gradient(135deg, #667eea15 0%, #764ba215 100%);
    border-radius: 12px;
    padding: 1.5rem;
    border-left: 4px solid var(--primary-color);
}

.interest-box h3 {
    color: var(--primary-color);
    margin-bottom: 1rem;
    font-size: 1.3rem;
}

.interest-box ul {
    list-style: none;
    padding-left: 0;
}

.interest-box li {
    padding: 0.5rem 0;
    color: var(--text-dark);
    position: relative;
    padding-left: 1.5rem;
}

.interest-box li:before {
    content: "▹";
    position: absolute;
    left: 0;
    color: var(--secondary-color);
    font-weight: bold;
}

/* Timeline Items */
.timeline-item {
    background: var(--white);
    border-radius: 12px;
    padding: 2rem;
    margin-bottom: 2rem;
    box-shadow: var(--shadow);
    border-left: 4px solid var(--secondary-color);
    transition: transform 0.3s ease, box-shadow 0.3s ease;
}

.timeline-item:hover {
    transform: translateX(5px);
    box-shadow: var(--shadow-lg);
}

.timeline-header {
    display: flex;
    justify-content: space-between;
    align-items: flex-start;
    margin-bottom: 1rem;
    flex-wrap: wrap;
    gap: 1rem;
}

.timeline-header h3 {
    color: var(--primary-color);
    font-size: 1.5rem;
    margin-bottom: 0.3rem;
}

.institution-name {
    color: var(--text-light);
    font-size: 1.1rem;
}

.date {
    color: var(--text-light);
    font-weight: 500;
    font-size: 0.95rem;
    white-space: nowrap;
}

.timeline-item p {
    color: var(--text-dark);
    margin: 0.5rem 0;
}

.timeline-item ul {
    margin-top: 0.5rem;
    padding-left: 1.5rem;
    color: var(--text-light);
}

.timeline-item li {
    margin: 0.3rem 0;
}

/* Project Items */
.project-item {
    background: var(--white);
    border-radius: 12px;
    padding: 1.5rem;
    margin-bottom: 1.5rem;
    box-shadow: var(--shadow);
    border-left: 4px solid var(--accent-color);
}

.project-item.featured {
    border-left-color: #f59e0b;
    background: linear-gradient(135deg, #fef3c715 0%, #fbbf2415 100%);
}

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

.project-item h4 {
    color: var(--text-dark);
    font-size: 1.2rem;
    margin-bottom: 0.5rem;
}

.project-item p {
    color: var(--text-light);
    margin: 0.3rem 0;
}

/* Publications */
.pub-category {
    color: var(--primary-color);
    font-size: 1.8rem;
    margin: 2rem 0 1.5rem;
    font-weight: 600;
}

.publication {
    background: var(--white);
    border-radius: 12px;
    padding: 1.5rem;
    margin-bottom: 1.5rem;
    box-shadow: var(--shadow);
    transition: transform 0.3s ease;
}

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

.pub-text {
    color: var(--text-dark);
    line-height: 1.8;
    margin-bottom: 1rem;
}

.citation-badge {
    display: inline-block;
    background: linear-gradient(135deg, #10b981 0%, #059669 100%);
    color: var(--white);
    padding: 0.4rem 1rem;
    border-radius: 20px;
    font-weight: 600;
    font-size: 0.9rem;
    margin-right: 0.5rem;
}

.author-note {
    display: inline-block;
    background: linear-gradient(135deg, #f59e0b 0%, #d97706 100%);
    color: var(--white);
    padding: 0.4rem 1rem;
    border-radius: 20px;
    font-weight: 600;
    font-size: 0.9rem;
}

.review-status {
    color: var(--text-light);
    font-style: italic;
    margin: 0.3rem 0;
}

/* Teaching Items */
.teaching-item {
    background: var(--white);
    border-radius: 12px;
    padding: 2rem;
    margin-bottom: 2rem;
    box-shadow: var(--shadow);
    border-left: 4px solid #8b5cf6;
}

.student-feedback {
    margin-top: 1rem;
    padding: 1rem;
    background: var(--bg-light);
    border-radius: 8px;
    border-left: 3px solid var(--accent-color);
}

.student-feedback p {
    color: var(--text-light);
    font-style: italic;
    margin: 0.5rem 0;
}

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

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

.skill-category h3 {
    color: var(--primary-color);
    margin-bottom: 1rem;
    font-size: 1.5rem;
}

.skill-category ul {
    list-style: none;
    padding: 0;
}

.skill-category li {
    padding: 0.6rem 0;
    color: var(--text-dark);
    border-bottom: 1px solid var(--bg-light);
}

.skill-category li:last-child {
    border-bottom: none;
}

/* Awards */
.awards-title {
    color: var(--primary-color);
    font-size: 1.8rem;
    margin: 2rem 0 1.5rem;
    font-weight: 600;
}

.award-item {
    background: var(--white);
    border-radius: 12px;
    padding: 1.5rem;
    margin-bottom: 1.5rem;
    box-shadow: var(--shadow);
    border-left: 4px solid #f59e0b;
}

.award-item h4 {
    color: var(--primary-color);
    font-size: 1.3rem;
    margin-bottom: 0.5rem;
}

.award-item p {
    color: var(--text-light);
    margin: 0.3rem 0;
}

/* Contact */
.contact-card {
    background: var(--white);
    border-radius: 12px;
    padding: 3rem;
    box-shadow: var(--shadow-lg);
}

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

.contact-info p {
    color: var(--text-dark);
    margin: 1rem 0;
    font-size: 1.1rem;
}

.contact-links {
    display: flex;
    gap: 1rem;
    margin-top: 2rem;
    flex-wrap: wrap;
}

.contact-btn {
    display: inline-block;
    background: linear-gradient(135deg, var(--primary-color) 0%, var(--secondary-color) 100%);
    color: var(--white);
    padding: 0.8rem 1.5rem;
    border-radius: 8px;
    font-weight: 600;
    transition: all 0.3s ease;
}

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

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

.footer p {
    margin: 0.3rem 0;
    opacity: 0.8;
}

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

    .hero-content {
        flex-direction: column;
        text-align: center;
    }

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

    .hero-avatar {
        width: 150px;
        height: 150px;
    }

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

    .timeline-header {
        flex-direction: column;
    }

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

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

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

.card, .timeline-item, .project-item, .publication {
    animation: fadeIn 0.6s ease-out;
}