/* ===== CSS Variables & Reset ===== */
:root {
    --color-bg: #ffffff;
    --color-bg-alt: #f8f9fa;
    --color-text: #2d3436;
    --color-text-secondary: #636e72;
    --color-primary: #0984e3;
    --color-primary-dark: #0769b5;
    --color-border: #e9ecef;
    --color-card-shadow: rgba(0, 0, 0, 0.06);
    --font-main: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', sans-serif;
    --max-width: 960px;
    --nav-height: 60px;
    --radius: 10px;
    --transition: 0.3s ease;
}

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

html {
    scroll-behavior: smooth;
    scroll-padding-top: var(--nav-height);
}

body {
    font-family: var(--font-main);
    color: var(--color-text);
    background: var(--color-bg);
    line-height: 1.7;
    font-size: 16px;
    -webkit-font-smoothing: antialiased;
}

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

a:hover {
    color: var(--color-primary-dark);
}

img {
    max-width: 100%;
    display: block;
}

.container {
    max-width: var(--max-width);
    margin: 0 auto;
    padding: 0 24px;
}

/* ===== Navbar ===== */
.navbar {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    height: var(--nav-height);
    background: rgba(255, 255, 255, 0.92);
    backdrop-filter: blur(12px);
    -webkit-backdrop-filter: blur(12px);
    border-bottom: 1px solid var(--color-border);
    z-index: 1000;
    transition: box-shadow var(--transition);
}

.navbar.scrolled {
    box-shadow: 0 2px 20px var(--color-card-shadow);
}

.nav-container {
    max-width: var(--max-width);
    margin: 0 auto;
    padding: 0 24px;
    height: 100%;
    display: flex;
    align-items: center;
    justify-content: space-between;
}

.nav-logo {
    font-size: 1.2rem;
    font-weight: 700;
    color: var(--color-text);
}

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

.nav-links {
    display: flex;
    list-style: none;
    gap: 32px;
}

.nav-links a {
    color: var(--color-text-secondary);
    font-size: 0.9rem;
    font-weight: 500;
    position: relative;
    padding: 4px 0;
}

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

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

.nav-links a:hover::after {
    width: 100%;
}

.nav-toggle {
    display: none;
    background: none;
    border: none;
    font-size: 1.3rem;
    color: var(--color-text);
    cursor: pointer;
}

/* ===== Hero ===== */
.hero {
    padding-top: calc(var(--nav-height) + 40px);
    padding-bottom: 40px;
}

.hero-container {
    max-width: var(--max-width);
    margin: 0 auto;
    padding: 0 24px;
    display: flex;
    align-items: center;
    gap: 40px;
}

.hero-text {
    flex: 1;
}

.hero-text h1 {
    font-size: 2.6rem;
    font-weight: 700;
    margin-bottom: 12px;
    letter-spacing: -0.5px;
}

.hero-subtitle {
    font-size: 1.15rem;
    color: var(--color-text-secondary);
    margin-bottom: 6px;
}

.hero-affiliation {
    font-size: 1rem;
    color: var(--color-text-secondary);
    margin-bottom: 24px;
}

.hero-links {
    display: flex;
    gap: 16px;
}

.hero-links a {
    display: flex;
    align-items: center;
    justify-content: center;
    width: 42px;
    height: 42px;
    border-radius: 50%;
    background: var(--color-bg-alt);
    color: var(--color-text-secondary);
    font-size: 1.1rem;
    transition: all var(--transition);
}

.hero-links a:hover {
    background: var(--color-primary);
    color: #fff;
    transform: translateY(-2px);
}

.hero-avatar {
    flex-shrink: 0;
}

.hero-avatar img {
    width: 200px;
    height: 200px;
    border-radius: 50%;
    object-fit: cover;
    border: 4px solid var(--color-bg-alt);
    box-shadow: 0 8px 30px var(--color-card-shadow);
}

/* ===== Sections ===== */
.section {
    padding: 70px 0;
}

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

.section-title {
    font-size: 1.8rem;
    font-weight: 700;
    margin-bottom: 36px;
    position: relative;
    display: inline-block;
}

.section-title::after {
    content: '';
    position: absolute;
    bottom: -8px;
    left: 0;
    width: 40px;
    height: 3px;
    background: var(--color-primary);
    border-radius: 2px;
}

/* ===== About ===== */
.about-wrapper {
    display: flex;
    gap: 40px;
    align-items: flex-start;
}

.about-photo {
    flex-shrink: 0;
    width: 220px;
    height: 280px;
    border-radius: var(--radius);
    overflow: hidden;
    background: var(--color-border);
    box-shadow: 0 8px 30px var(--color-card-shadow);
}

.about-photo.no-img {
    background: linear-gradient(135deg, #dfe6e9, #b2bec3);
}

.about-photo img {
    width: 100%;
    height: 100%;
    object-fit: cover;
}

.about-content {
    flex: 1;
}

.about-content p {
    font-size: 1.05rem;
    color: var(--color-text-secondary);
    margin-bottom: 16px;
    max-width: 720px;
}

/* ===== News ===== */
.news-list {
    list-style: none;
    max-width: 720px;
}

.news-list li {
    padding: 12px 0;
    border-bottom: 1px solid var(--color-border);
    font-size: 0.95rem;
    color: var(--color-text-secondary);
}

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

.news-date {
    display: inline-block;
    font-weight: 600;
    color: var(--color-primary);
    min-width: 90px;
    margin-right: 12px;
}

/* ===== Publications ===== */
.pub-list {
    display: flex;
    flex-direction: column;
    gap: 28px;
}

.pub-item {
    display: flex;
    gap: 24px;
    padding: 24px;
    background: var(--color-bg-alt);
    border-radius: var(--radius);
    transition: transform var(--transition), box-shadow var(--transition);
}

.pub-item:hover {
    transform: translateY(-2px);
    box-shadow: 0 8px 30px var(--color-card-shadow);
}

.pub-thumb {
    flex-shrink: 0;
    width: 180px;
    min-height: 120px;
    border-radius: 8px;
    overflow: hidden;
    background: var(--color-border);
    display: flex;
    align-items: center;
    justify-content: center;
}

.pub-thumb.no-img {
    background: linear-gradient(135deg, #dfe6e9, #b2bec3);
}

.pub-thumb img {
    width: 100%;
    height: 100%;
    object-fit: cover;
}

.pub-thumb canvas.pdf-preview {
    width: 100%;
    height: auto;
    display: block;
    border-radius: 8px;
}

.pub-info {
    flex: 1;
}

.pub-title {
    font-size: 1.1rem;
    font-weight: 600;
    margin-bottom: 6px;
    color: var(--color-text);
}

.pub-authors {
    font-size: 0.9rem;
    color: var(--color-text-secondary);
    margin-bottom: 4px;
}

.pub-venue {
    font-size: 0.88rem;
    color: var(--color-primary);
    font-weight: 500;
    margin-bottom: 10px;
}

.pub-links {
    display: flex;
    gap: 12px;
    flex-wrap: wrap;
}

.pub-links a {
    display: inline-flex;
    align-items: center;
    gap: 5px;
    font-size: 0.82rem;
    padding: 4px 12px;
    border-radius: 20px;
    background: var(--color-bg);
    border: 1px solid var(--color-border);
    color: var(--color-text-secondary);
    transition: all var(--transition);
}

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

/* ===== Projects ===== */
.project-grid {
    display: grid;
    grid-template-columns: repeat(2, 1fr);
    gap: 24px;
}

.project-card {
    background: var(--color-bg);
    border-radius: var(--radius);
    overflow: hidden;
    border: 1px solid var(--color-border);
    transition: transform var(--transition), box-shadow var(--transition);
}

.project-card:hover {
    transform: translateY(-4px);
    box-shadow: 0 12px 40px var(--color-card-shadow);
}

.project-img {
    height: 160px;
    background: linear-gradient(135deg, #dfe6e9, #b2bec3);
    overflow: hidden;
}

.project-img.no-img {
    display: flex;
    align-items: center;
    justify-content: center;
}

.project-img img {
    width: 100%;
    height: 100%;
    object-fit: cover;
}

.project-body {
    padding: 20px;
}

.project-body h3 {
    font-size: 1.1rem;
    margin-bottom: 8px;
}

.project-body p {
    font-size: 0.9rem;
    color: var(--color-text-secondary);
    margin-bottom: 12px;
}

.project-tags {
    display: flex;
    gap: 8px;
    flex-wrap: wrap;
    margin-bottom: 14px;
}

.project-tags span {
    font-size: 0.75rem;
    padding: 3px 10px;
    border-radius: 20px;
    background: #e8f4fd;
    color: var(--color-primary);
    font-weight: 500;
}

.project-links {
    display: flex;
    gap: 12px;
}

.project-links a {
    font-size: 0.85rem;
    color: var(--color-text-secondary);
    display: inline-flex;
    align-items: center;
    gap: 5px;
}

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

/* ===== Timeline (Experience) ===== */
.timeline {
    position: relative;
    padding-left: 32px;
}

.timeline::before {
    content: '';
    position: absolute;
    left: 7px;
    top: 8px;
    bottom: 8px;
    width: 2px;
    background: var(--color-border);
}

.timeline-item {
    position: relative;
    margin-bottom: 36px;
}

.timeline-item:last-child {
    margin-bottom: 0;
}

.timeline-dot {
    position: absolute;
    left: -32px;
    top: 6px;
    width: 16px;
    height: 16px;
    border-radius: 50%;
    background: var(--color-bg);
    border: 3px solid var(--color-primary);
}

.timeline-content h3 {
    font-size: 1.1rem;
    font-weight: 600;
    margin-bottom: 4px;
}

.timeline-org {
    font-size: 0.95rem;
    color: var(--color-primary);
    font-weight: 500;
    margin-bottom: 2px;
}

.timeline-date {
    font-size: 0.85rem;
    color: var(--color-text-secondary);
    margin-bottom: 8px;
}

.timeline-content p:last-child {
    font-size: 0.92rem;
    color: var(--color-text-secondary);
}

/* ===== Contact ===== */
.contact-content p {
    font-size: 1.05rem;
    color: var(--color-text-secondary);
    margin-bottom: 24px;
}

.contact-info {
    display: flex;
    flex-direction: column;
    gap: 16px;
}

.contact-item {
    display: flex;
    align-items: center;
    gap: 12px;
    font-size: 1rem;
}

.contact-item i {
    width: 36px;
    height: 36px;
    display: flex;
    align-items: center;
    justify-content: center;
    border-radius: 50%;
    background: var(--color-bg);
    color: var(--color-primary);
    font-size: 0.9rem;
    border: 1px solid var(--color-border);
}

/* ===== Footer ===== */
.footer {
    padding: 28px 0;
    text-align: center;
    border-top: 1px solid var(--color-border);
    font-size: 0.88rem;
    color: var(--color-text-secondary);
}

/* ===== Responsive ===== */
@media (max-width: 768px) {
    .nav-links {
        display: none;
        position: absolute;
        top: var(--nav-height);
        left: 0;
        right: 0;
        background: rgba(255, 255, 255, 0.98);
        backdrop-filter: blur(12px);
        flex-direction: column;
        padding: 20px 24px;
        gap: 16px;
        border-bottom: 1px solid var(--color-border);
        box-shadow: 0 8px 30px var(--color-card-shadow);
    }

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

    .nav-toggle {
        display: block;
    }

    .hero-container {
        flex-direction: column;
        text-align: center;
        gap: 24px;
    }

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

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

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

    .pub-item {
        flex-direction: column;
    }

    .about-wrapper {
        flex-direction: column;
        align-items: center;
        text-align: center;
    }

    .about-photo {
        width: 180px;
        height: 230px;
    }

    .pub-thumb {
        width: 100%;
        height: 160px;
    }

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

@media (max-width: 480px) {
    .hero-text h1 {
        font-size: 1.7rem;
    }

    .section {
        padding: 50px 0;
    }

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

/* ===== Fade-in Animation ===== */
.fade-in {
    opacity: 0;
    transform: translateY(24px);
    transition: opacity 0.6s ease, transform 0.6s ease;
}

.fade-in.visible {
    opacity: 1;
    transform: translateY(0);
}