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

:root {
    --primary-color: #003366;
    --secondary-color: #0066cc;
    --accent-color: #ff6b35;
    --text-color: #333;
    --light-bg: #f8f9fa;
    --white: #ffffff;
    --border-color: #e0e0e0;
    --shadow: 0 2px 10px rgba(0, 0, 0, 0.1);
    --shadow-hover: 0 4px 20px rgba(0, 0, 0, 0.15);
}

body {
    font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
    line-height: 1.6;
    color: var(--text-color);
    background-color: var(--white);
}

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

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

nav {
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.logo {
    font-size: 1.5rem;
    font-weight: 600;
}

.nav-links {
    display: flex;
    gap: 2rem;
}

.nav-links a {
    color: var(--white);
    text-decoration: none;
    font-weight: 500;
    transition: color 0.3s ease;
    padding: 0.5rem 1rem;
    border-radius: 4px;
}

.nav-links a:hover {
    background-color: rgba(255, 255, 255, 0.1);
}

/* Hero Section */
.hero {
    background: linear-gradient(135deg, #003366 0%, #0066cc 100%);
    color: var(--white);
    padding: 4rem 0;
}

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

.profile-image {
    position: relative;
}

.profile-image img {
    width: 100%;
    border-radius: 12px;
    box-shadow: var(--shadow-hover);
    border: 5px solid var(--white);
}

.profile-info h1 {
    font-size: 2.5rem;
    margin-bottom: 0.5rem;
    font-weight: 700;
}

.title {
    font-size: 1.3rem;
    margin-bottom: 1.5rem;
    opacity: 0.95;
    font-weight: 500;
}

.institution {
    margin-bottom: 1.5rem;
    line-height: 1.8;
}

.institution p {
    margin-bottom: 0.3rem;
}

.contact-info {
    margin-bottom: 2rem;
    line-height: 1.8;
}

.contact-info p {
    margin-bottom: 0.5rem;
}

.spam-protection::before {
    content: "@";
}

.office-hours {
    background-color: rgba(255, 255, 255, 0.1);
    padding: 1.5rem;
    border-radius: 8px;
    border-left: 4px solid var(--accent-color);
}

.office-hours h3 {
    margin-bottom: 0.5rem;
    font-size: 1.2rem;
}

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

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

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

.section-title {
    margin-top: 3rem;
}

/* Timeline */
.timeline {
    position: relative;
    padding-left: 2rem;
}

.timeline::before {
    content: '';
    position: absolute;
    left: 0;
    top: 0;
    bottom: 0;
    width: 3px;
    background: linear-gradient(180deg, var(--secondary-color) 0%, var(--accent-color) 100%);
}

.timeline-item {
    display: grid;
    grid-template-columns: 200px 1fr;
    gap: 2rem;
    margin-bottom: 2rem;
    position: relative;
}

.timeline-item::before {
    content: '';
    position: absolute;
    left: -2.5rem;
    top: 0.5rem;
    width: 15px;
    height: 15px;
    border-radius: 50%;
    background-color: var(--accent-color);
    border: 3px solid var(--white);
    box-shadow: 0 0 0 3px var(--secondary-color);
}

.timeline-date {
    font-weight: 600;
    color: var(--secondary-color);
    font-size: 1rem;
}

.timeline-content h3 {
    font-size: 1.2rem;
    margin-bottom: 0.5rem;
    color: var(--primary-color);
}

.timeline-content p {
    color: var(--text-color);
}

/* Research Section */
.research-description {
    font-size: 1.1rem;
    line-height: 1.8;
    margin-bottom: 3rem;
    padding: 1.5rem;
    background-color: var(--white);
    border-left: 4px solid var(--secondary-color);
    border-radius: 4px;
}

.research-list {
    display: grid;
    gap: 1.5rem;
}

.research-item {
    background-color: var(--white);
    padding: 1.5rem;
    border-radius: 8px;
    box-shadow: var(--shadow);
    transition: transform 0.3s ease, box-shadow 0.3s ease;
    border-left: 4px solid var(--border-color);
}

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

.research-item.published {
    border-left-color: var(--secondary-color);
}

.research-item.working {
    border-left-color: var(--accent-color);
}

.research-item h3 {
    font-size: 1.2rem;
    margin-bottom: 0.8rem;
    color: var(--primary-color);
    line-height: 1.4;
}

.research-item .authors {
    font-size: 0.95rem;
    color: #666;
    margin-bottom: 0.5rem;
    font-style: italic;
}

.research-item .publication {
    font-size: 0.95rem;
    color: var(--text-color);
    font-weight: 500;
}

.research-item .note {
    font-size: 0.9rem;
    color: #666;
    margin-top: 0.5rem;
}

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

.contact-card {
    background-color: var(--white);
    padding: 2rem;
    border-radius: 8px;
    box-shadow: var(--shadow);
    border-top: 4px solid var(--secondary-color);
    transition: transform 0.3s ease, box-shadow 0.3s ease;
}

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

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

.contact-card p {
    line-height: 1.8;
}

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

/* Responsive Design */
@media (max-width: 768px) {
    .hero-content {
        grid-template-columns: 1fr;
        text-align: center;
    }

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

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

    .nav-links {
        gap: 1rem;
    }

    .nav-links a {
        padding: 0.3rem 0.5rem;
        font-size: 0.9rem;
    }

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

    .timeline-date {
        font-size: 0.9rem;
    }

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

    .section h2 {
        font-size: 1.5rem;
    }
}

@media (max-width: 480px) {
    .logo {
        font-size: 1.2rem;
    }

    .nav-links {
        flex-wrap: wrap;
        gap: 0.5rem;
    }

    .profile-info h1 {
        font-size: 1.5rem;
    }

    .title {
        font-size: 1.1rem;
    }

    .section {
        padding: 2rem 0;
    }
}

/* Smooth Scrolling */
html {
    scroll-behavior: smooth;
}

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

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