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

:root {
    --bg-primary: #0d1117;
    --bg-secondary: #161b22;
    --bg-card: #21262d;
    --text-primary: #e6edf3;
    --text-secondary: #8b949e;
    --accent: #58a6ff;
    --accent-hover: #79b8ff;
    --border: #30363d;
    --font-main: 'Segoe UI', system-ui, -apple-system, sans-serif;
    --font-mono: 'SF Mono', 'Consolas', monospace;
}

html {
    scroll-behavior: smooth;
}

body {
    font-family: var(--font-main);
    background-color: var(--bg-primary);
    color: var(--text-primary);
    line-height: 1.6;
    font-size: 16px;
}

a {
    color: var(--accent);
    text-decoration: none;
    transition: color 0.2s ease;
}

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

.container {
    max-width: 900px;
    margin: 0 auto;
    padding: 0 20px;
}

/* Navigation */
.navbar {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    background-color: rgba(13, 17, 23, 0.95);
    backdrop-filter: blur(10px);
    border-bottom: 1px solid var(--border);
    padding: 15px 30px;
    display: flex;
    justify-content: space-between;
    align-items: center;
    z-index: 1000;
}

.nav-brand {
    font-size: 1.2rem;
    font-weight: 600;
    color: var(--text-primary);
}

.nav-links {
    display: flex;
    list-style: none;
    gap: 30px;
}

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

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

.nav-toggle {
    display: none;
    background: none;
    border: none;
    cursor: pointer;
    padding: 10px;
}

.hamburger {
    display: block;
    width: 25px;
    height: 2px;
    background-color: var(--text-primary);
    position: relative;
}

.hamburger::before,
.hamburger::after {
    content: '';
    position: absolute;
    width: 25px;
    height: 2px;
    background-color: var(--text-primary);
    left: 0;
}

.hamburger::before {
    top: -8px;
}

.hamburger::after {
    top: 8px;
}

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

.hero {
    padding-top: 120px;
}

h1 {
    font-size: 2.5rem;
    font-weight: 600;
    margin-bottom: 10px;
}

h2 {
    font-size: 1.8rem;
    font-weight: 600;
    margin-bottom: 30px;
    padding-bottom: 10px;
    border-bottom: 2px solid var(--border);
}

h3 {
    font-size: 1.2rem;
    font-weight: 600;
    margin-bottom: 10px;
}

/* Hero Section */
.hero-content {
    display: flex;
    gap: 40px;
    align-items: flex-start;
}

.profile-photo {
    width: 180px;
    height: 180px;
    border-radius: 50%;
    object-fit: cover;
    border: 3px solid var(--border);
}

.hero-text {
    flex: 1;
}

.subtitle {
    font-size: 1.3rem;
    color: var(--accent);
    margin-bottom: 5px;
}

.affiliation {
    color: var(--text-secondary);
    margin-bottom: 20px;
}

.intro {
    margin-bottom: 20px;
    color: var(--text-secondary);
}

.social-links {
    display: flex;
    gap: 20px;
    flex-wrap: wrap;
}

.social-links a {
    padding: 8px 16px;
    border: 1px solid var(--border);
    border-radius: 6px;
    font-size: 0.9rem;
    transition: all 0.2s ease;
}

.social-links a:hover {
    background-color: var(--bg-card);
    border-color: var(--accent);
}

/* Research Section */
.research-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: 20px;
}

.research-card {
    background-color: var(--bg-secondary);
    border: 1px solid var(--border);
    border-radius: 8px;
    padding: 25px;
    transition: border-color 0.2s ease;
}

.research-card:hover {
    border-color: var(--accent);
}

.research-card h3 {
    color: var(--accent);
}

.research-card p {
    color: var(--text-secondary);
    font-size: 0.95rem;
}

/* Publications Section */
.publication-list {
    list-style: none;
}

.publication-item {
    background-color: var(--bg-secondary);
    border: 1px solid var(--border);
    border-radius: 8px;
    padding: 20px 25px;
    margin-bottom: 15px;
    transition: border-color 0.2s ease;
}

.publication-item:hover {
    border-color: var(--accent);
}

.publication-item.preprint {
    border-left: 3px solid var(--text-secondary);
}

.pub-title {
    display: block;
    font-weight: 600;
    font-size: 1.05rem;
    margin-bottom: 8px;
    color: var(--text-primary);
}

.pub-authors {
    display: block;
    color: var(--text-secondary);
    font-size: 0.9rem;
    margin-bottom: 5px;
}

.pub-venue {
    display: block;
    color: var(--text-secondary);
    font-size: 0.9rem;
    font-style: italic;
    margin-bottom: 12px;
}

.pub-links {
    display: flex;
    gap: 15px;
}

.pub-links a {
    font-size: 0.85rem;
    padding: 4px 12px;
    background-color: var(--bg-card);
    border-radius: 4px;
    transition: background-color 0.2s ease;
}

.pub-links a:hover {
    background-color: var(--border);
}

/* CV Section */
#cv {
    text-align: center;
}

#cv p {
    color: var(--text-secondary);
    margin-bottom: 25px;
}

.cv-button {
    display: inline-block;
    padding: 12px 30px;
    background-color: var(--accent);
    color: var(--bg-primary);
    font-weight: 600;
    border-radius: 6px;
    transition: background-color 0.2s ease;
}

.cv-button:hover {
    background-color: var(--accent-hover);
    color: var(--bg-primary);
}

/* Contact Section */
#contact {
    text-align: center;
}

#contact > .container > p {
    color: var(--text-secondary);
    margin-bottom: 25px;
}

.contact-info {
    display: inline-block;
    text-align: left;
    background-color: var(--bg-secondary);
    padding: 25px 40px;
    border-radius: 8px;
    border: 1px solid var(--border);
}

.contact-info p {
    margin-bottom: 10px;
    color: var(--text-secondary);
}

.contact-info p:last-child {
    margin-bottom: 0;
}

/* Footer */
footer {
    background-color: var(--bg-secondary);
    border-top: 1px solid var(--border);
    padding: 25px 0;
    text-align: center;
}

footer p {
    color: var(--text-secondary);
    font-size: 0.9rem;
}

/* Mobile Responsiveness */
@media (max-width: 768px) {
    .nav-toggle {
        display: block;
    }

    .nav-links {
        position: absolute;
        top: 100%;
        left: 0;
        right: 0;
        background-color: var(--bg-secondary);
        flex-direction: column;
        padding: 20px;
        gap: 15px;
        border-bottom: 1px solid var(--border);
        display: none;
    }

    .nav-links.active {
        display: flex;
    }

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

    .social-links {
        justify-content: center;
    }

    h1 {
        font-size: 2rem;
    }

    h2 {
        font-size: 1.5rem;
    }

    .section {
        padding: 60px 0;
    }

    .profile-photo {
        width: 150px;
        height: 150px;
    }
}

@media (max-width: 480px) {
    .navbar {
        padding: 15px 20px;
    }

    .social-links a {
        padding: 6px 12px;
        font-size: 0.85rem;
    }

    .publication-item {
        padding: 15px;
    }

    .pub-links {
        flex-wrap: wrap;
        gap: 10px;
    }
}

/* Experience Section - Timeline Style */


/* Experience Section - Timeline Style */
.experience-list {
    list-style: none;
    position: relative;
    padding-left: 30px;
}

.experience-list::before {
    content: '';
    position: absolute;
    left: 6px;
    top: 0;
    bottom: 0;
    width: 2px;
    background: linear-gradient(to bottom, var(--accent), var(--border));
}

.experience-item {
    position: relative;
    padding: 20px 25px;
    margin-bottom: 25px;
    background-color: var(--bg-secondary);
    border: 1px solid var(--border);
    border-radius: 8px;
    transition: all 0.3s ease;
}

.experience-item::before {
    content: '';
    position: absolute;
    left: -30px;
    top: 28px;
    width: 14px;
    height: 14px;
    background-color: var(--accent);
    border: 3px solid var(--bg-primary);
    border-radius: 50%;
    z-index: 1;
}

.experience-item:hover {
    border-color: var(--accent);
    transform: translateX(5px);
}

.exp-header {
    display: flex;
    justify-content: space-between;
    align-items: flex-start;
    flex-wrap: wrap;
    gap: 10px;
    margin-bottom: 8px;
}

.exp-title {
    font-weight: 600;
    font-size: 1.15rem;
    color: var(--text-primary);
}

.exp-date {
    padding: 4px 12px;
    background-color: var(--bg-card);
    border-radius: 15px;
    color: var(--accent);
    font-size: 0.85rem;
    font-weight: 500;
}

.exp-company {
    display: block;
    color: var(--accent);
    font-size: 1rem;
    font-weight: 500;
    margin-bottom: 12px;
}

.exp-description {
    color: var(--text-secondary);
    font-size: 0.95rem;
    line-height: 1.6;
}

@media (max-width: 480px) {
    .experience-list {
        padding-left: 20px;
    }

    .experience-item::before {
        left: -20px;
        width: 10px;
        height: 10px;
    }

    .exp-header {
        flex-direction: column;
        align-items: flex-start;
    }

    .experience-item:hover {
        transform: none;
    }
}

/* Two Column Layout */
.two-column-grid {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 50px;
    align-items: start;
}

.two-column-grid .column {
    width: 100%;
}

.two-column-grid .column h2 {
    margin-bottom: 25px;
    border-bottom: 2px solid var(--border);
    padding-bottom: 10px;
}

/* Research Interests in column */
.two-column-grid .interests-grid {
    display: flex;
    flex-wrap: wrap;
    gap: 12px;
}

/* Education Section */
.education-list {
    list-style: none;
}

.education-item {
    padding: 18px 0;
    border-bottom: 1px solid var(--border);
}

.education-item:first-child {
    padding-top: 0;
}

.education-item:last-child {
    border-bottom: none;
    padding-bottom: 0;
}

.edu-header {
    display: flex;
    justify-content: space-between;
    align-items: flex-start;
    flex-wrap: wrap;
    gap: 10px;
    margin-bottom: 5px;
}

.edu-degree {
    font-weight: 600;
    font-size: 1.05rem;
    color: var(--text-primary);
}

.edu-date {
    color: var(--accent);
    font-size: 0.85rem;
    font-weight: 500;
}

.edu-school {
    display: block;
    color: var(--text-secondary);
    font-size: 0.95rem;
    margin-bottom: 5px;
}

.edu-details {
    color: var(--text-secondary);
    font-size: 0.85rem;
    font-style: italic;
}

/* Responsive - Stack columns on mobile */
@media (max-width: 768px) {
    .two-column-grid {
        grid-template-columns: 1fr;
        gap: 40px;
    }

    .edu-header {
        flex-direction: column;
        gap: 3px;
    }
}

/* Research Interests List - Bullet Style */
.interests-list {
    list-style: none;
}

.interest-list-item {
    padding: 10px 0;
    border-bottom: 1px solid var(--border);
    color: var(--text-secondary);
    font-size: 1rem;
    position: relative;
    padding-left: 25px;
    transition: color 0.2s ease;
}

.interest-list-item:first-child {
    padding-top: 0;
}

.interest-list-item:last-child {
    border-bottom: none;
}

.interest-list-item::before {
    content: '';
    position: absolute;
    left: 0;
    top: 50%;
    transform: translateY(-50%);
    width: 8px;
    height: 8px;
    background-color: var(--accent);
    border-radius: 50%;
}

.interest-list-item:first-child::before {
    top: 14px;
}

.interest-list-item:hover {
    color: var(--accent);
}