:root {
    --color-bg: #ffffff;
    --color-text: #2c2c2c;
    --color-text-light: #666666;
    --color-accent: #1a5276;
    --color-accent-light: #2980b9;
    --color-border: #e8e8e8;
    --color-section-bg: #fafafa;
    --color-card-bg: #ffffff;
    --color-shadow: rgba(0, 0, 0, 0.08);
    --font-heading: 'Playfair Display', Georgia, serif;
    --font-body: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
    --max-width: 960px;
    --nav-height: 60px;
}

body.dark {
    --color-bg: #1a1a2e;
    --color-text: #e0e0e0;
    --color-text-light: #a0a0a0;
    --color-accent: #5dade2;
    --color-accent-light: #85c1e9;
    --color-border: #2c2c4a;
    --color-section-bg: #16213e;
    --color-card-bg: #1f2940;
    --color-shadow: rgba(0, 0, 0, 0.3);
}

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

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

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

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

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

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

/* ===== Navigation ===== */
#navbar {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    height: var(--nav-height);
    background: rgba(255, 255, 255, 0.95);
    backdrop-filter: blur(10px);
    border-bottom: 1px solid var(--color-border);
    z-index: 1000;
    transition: box-shadow 0.3s;
}

body.dark #navbar {
    background: rgba(26, 26, 46, 0.95);
}

#navbar.scrolled {
    box-shadow: 0 2px 20px var(--color-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-name {
    font-family: var(--font-heading);
    font-size: 1.2rem;
    font-weight: 700;
    color: var(--color-text);
}

.nav-name:hover {
    color: var(--color-accent);
}

.nav-links {
    display: flex;
    gap: 28px;
}

.nav-links a {
    font-size: 0.9rem;
    font-weight: 400;
    color: var(--color-text-light);
    letter-spacing: 0.02em;
    position: relative;
}

.nav-links a::after {
    content: '';
    position: absolute;
    bottom: -4px;
    left: 0;
    width: 0;
    height: 2px;
    background: var(--color-accent);
    transition: width 0.3s;
}

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

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

.nav-links a.active {
    color: var(--color-accent);
}

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

.theme-toggle {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    width: 36px;
    height: 36px;
    border-radius: 50%;
    background: none;
    border: 1px solid var(--color-border);
    color: var(--color-text-light);
    font-size: 1rem;
    cursor: pointer;
    transition: all 0.2s;
    margin-left: 12px;
}

.theme-toggle:hover {
    background: var(--color-accent);
    color: #fff;
    border-color: var(--color-accent);
}

.nav-toggle {
    display: none;
    flex-direction: column;
    gap: 5px;
    background: none;
    border: none;
    cursor: pointer;
    padding: 4px;
}

.nav-toggle span {
    display: block;
    width: 24px;
    height: 2px;
    background: var(--color-text);
    transition: all 0.3s;
}

/* ===== Header ===== */
#header {
    padding-top: calc(var(--nav-height) + 60px);
    padding-bottom: 60px;
}

.header-content {
    display: flex;
    align-items: flex-start;
    gap: 40px;
}

.header-photo {
    flex-shrink: 0;
}

.header-photo img {
    width: 180px;
    height: 180px;
    border-radius: 12px;
    object-fit: cover;
    box-shadow: 0 4px 20px var(--color-shadow);
}

.header-info h1 {
    font-family: var(--font-heading);
    font-size: 2.4rem;
    font-weight: 700;
    color: var(--color-text);
    margin-bottom: 4px;
}

.header-title {
    font-size: 1.15rem;
    color: var(--color-text-light);
    margin-bottom: 2px;
}

.header-affiliation {
    font-size: 1.05rem;
    margin-bottom: 8px;
}

.header-interests {
    font-size: 0.95rem;
    color: var(--color-text-light);
    margin-bottom: 16px;
    font-style: italic;
}

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

.header-links a {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    width: 40px;
    height: 40px;
    border-radius: 50%;
    background: var(--color-section-bg);
    color: var(--color-text-light);
    font-size: 1.1rem;
    transition: all 0.2s;
}

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

/* ===== Section Titles ===== */
.section-title {
    font-family: var(--font-heading);
    font-size: 1.8rem;
    font-weight: 700;
    color: var(--color-text);
    margin-bottom: 8px;
    padding-bottom: 12px;
    border-bottom: 3px solid var(--color-accent);
    display: inline-block;
}

.section-subtitle {
    font-size: 0.85rem;
    color: var(--color-text-light);
    margin-bottom: 32px;
}

/* ===== About ===== */
#about {
    padding: 60px 0;
    background: var(--color-section-bg);
}

.about-text {
    max-width: 780px;
    font-size: 1.05rem;
    line-height: 1.8;
}

.about-text p {
    margin-bottom: 12px;
}

.about-text p a {
    color: var(--color-accent);
    font-weight: 600;
    text-decoration: underline;
    text-decoration-color: var(--color-accent);
    text-underline-offset: 2px;
    transition: all 0.3s ease;
    padding: 0 2px;
}

.about-text p a:hover {
    color: #fff;
    background-color: var(--color-accent);
    border-radius: 3px;
    text-decoration: none;
}

.highlight-text {
    color: var(--color-accent);
    font-weight: 600;
    font-size: 1.12rem;
    padding: 20px 24px;
    background: linear-gradient(135deg, rgba(26, 82, 118, 0.12), rgba(41, 128, 185, 0.08));
    border-left: 5px solid var(--color-accent);
    border-radius: 0 10px 10px 0;
    box-shadow: 0 4px 15px rgba(26, 82, 118, 0.15);
}

[data-theme="dark"] .highlight-text {
    background: linear-gradient(135deg, rgba(93, 173, 226, 0.18), rgba(133, 193, 233, 0.12));
    box-shadow: 0 4px 15px rgba(93, 173, 226, 0.2);
}

.reach-out {
    color: #e74c3c;
    font-weight: 700;
}

/* ===== Book ===== */
#book {
    padding: 60px 0;
    background: var(--color-section-bg);
}

/* ===== Publications ===== */
#publications {
    padding: 60px 0;
}

.pub-item {
    display: flex;
    flex-wrap: wrap;
    gap: 24px;
    padding: 28px 0;
    border-bottom: 1px solid var(--color-border);
    align-items: stretch;
    min-height: 180px;
}

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

.pub-image {
    flex-shrink: 0;
    width: 220px;
    position: relative;
    display: flex;
    align-items: center;
}

.pub-image img {
    width: 100%;
    height: auto;
    max-height: 160px;
    object-fit: contain;
    border-radius: 8px;
    box-shadow: 0 2px 12px var(--color-shadow);
    cursor: pointer;
    transition: transform 0.2s, box-shadow 0.2s;
}

.pub-image img:hover {
    transform: scale(1.03);
    box-shadow: 0 4px 20px rgba(0, 0, 0, 0.15);
}

.pub-details {
    margin-top: 16px;
    padding-top: 16px;
    border-top: 1px dashed var(--color-border);
}

.pub-details.multi-images {
    display: flex;
    flex-wrap: wrap;
    gap: 12px;
}

.pub-detail-media {
    margin-bottom: 0;
    flex-shrink: 0;
}

.pub-details.multi-images .pub-detail-media img,
.pub-details.multi-images .pub-detail-media video {
    width: 180px;
    height: auto;
    border-radius: 8px;
    box-shadow: 0 2px 12px var(--color-shadow);
    cursor: pointer;
}

.pub-details:not(.multi-images) .pub-detail-media img,
.pub-details:not(.multi-images) .pub-detail-media video {
    width: 100%;
    max-width: 500px;
    height: auto;
    border-radius: 8px;
    box-shadow: 0 2px 12px var(--color-shadow);
    cursor: pointer;
}

.pub-detail-media img:hover,
.pub-detail-media video:hover {
    box-shadow: 0 4px 20px rgba(0, 0, 0, 0.15);
}

.lazy-img {
    background: linear-gradient(90deg, var(--color-section-bg) 25%, var(--color-border) 50%, var(--color-section-bg) 75%);
    background-size: 200% 100%;
    animation: shimmer 1.5s infinite;
    min-height: 100px;
}

.lazy-img[src] {
    animation: none;
    background: none;
}

@keyframes shimmer {
    0% { background-position: 200% 0; }
    100% { background-position: -200% 0; }
}

.lazy-video {
    background: var(--color-section-bg);
    min-height: 200px;
    display: block;
}

.pub-info {
    flex: 1;
}

.pub-year-title {
    font-size: 1.5rem;
    font-weight: 700;
    margin: 32px 0 16px;
    padding-bottom: 8px;
    border-bottom: 2px solid var(--color-accent);
    color: var(--color-text);
}

.pub-year-title:first-child {
    margin-top: 0;
}

.pub-title {
    font-size: 1.1rem;
    font-weight: 700;
    margin-bottom: 4px;
    line-height: 1.4;
}

.pub-title a {
    color: var(--color-text);
}

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

.pub-authors {
    font-size: 0.92rem;
    color: var(--color-text-light);
    margin-bottom: 2px;
}

.pub-venue {
    font-size: 0.92rem;
    color: var(--color-accent);
    font-weight: 600;
    margin-bottom: 2px;
}

.pub-note {
    font-size: 0.85rem;
    color: var(--color-text-light);
    font-weight: 600;
    margin-bottom: 8px;
}

.pub-note.oral {
    color: #c0392b;
}

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

.pub-links a {
    font-size: 0.85rem;
    color: var(--color-text-light);
    display: inline-flex;
    align-items: center;
    gap: 4px;
    padding: 3px 10px;
    border-radius: 4px;
    background: var(--color-section-bg);
    transition: all 0.2s;
}

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

/* ===== Preprints ===== */
#preprints {
    padding: 60px 0;
    background: var(--color-section-bg);
}

/* ===== Projects ===== */
#projects {
    padding: 60px 0;
    background: var(--color-section-bg);
}

.project-grid {
    display: grid;
    grid-template-columns: 1fr;
    gap: 32px;
    margin-top: 8px;
    max-width: 900px;
    margin-left: auto;
    margin-right: auto;
}

.project-card {
    background: var(--color-card-bg);
    border-radius: 12px;
    overflow: hidden;
    box-shadow: 0 2px 16px var(--color-shadow);
    transition: transform 0.2s, box-shadow 0.2s;
    display: grid;
    grid-template-columns: 1fr 1fr;
    height: 360px;
}

.project-card:hover {
    transform: translateY(-4px);
    box-shadow: 0 8px 30px rgba(0, 0, 0, 0.12);
}

.project-media {
    width: 100%;
    height: 100%;
    overflow: hidden;
    background: #f0f0f0;
    display: flex;
    align-items: center;
    justify-content: center;
}

.project-media img {
    width: 100%;
    height: 100%;
    object-fit: contain;
    display: block;
    transition: transform 0.3s;
}

.project-media video {
    width: 100%;
    height: 100%;
    object-fit: contain;
    display: block;
    transition: transform 0.3s;
}

.project-media-grid {
    display: grid;
    grid-template-columns: repeat(2, 1fr);
    gap: 8px;
    padding: 12px;
    width: 100%;
    height: 100%;
    overflow-y: auto;
    align-content: start;
}

.project-media-grid img {
    width: 100%;
    height: auto;
    object-fit: contain;
    border-radius: 6px;
    background: #f5f5f5;
}

.project-card:hover .project-media img,
.project-card:hover .project-media video {
    transform: scale(1.05);
}

.project-body {
    padding: 16px 20px 20px;
}

.project-body h3 {
    font-size: 1.05rem;
    font-weight: 700;
    margin-bottom: 6px;
}

.project-body p {
    font-size: 0.88rem;
    color: var(--color-text-light);
    line-height: 1.5;
    margin-bottom: 12px;
}

.project-tags {
    display: flex;
    flex-wrap: wrap;
    gap: 6px;
    margin-bottom: 12px;
}

.project-tags span {
    font-size: 0.75rem;
    padding: 2px 10px;
    border-radius: 12px;
    background: #eef2f7;
    color: var(--color-accent);
    font-weight: 600;
}

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

.project-links .link-break {
    flex-basis: 100%;
    height: 0;
}

.project-links a {
    font-size: 0.85rem;
    color: var(--color-text-light);
    display: inline-flex;
    align-items: center;
    gap: 4px;
}

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

.project-links a img {
    height: 20px;
}

/* ===== FPDou Detail ===== */
#fpdou-detail {
    padding: 40px 0 60px;
}

.fpdou-back-btn {
    display: inline-flex;
    align-items: center;
    gap: 8px;
    padding: 10px 20px;
    background: var(--color-accent);
    color: #fff;
    border: none;
    border-radius: 8px;
    cursor: pointer;
    font-size: 0.95rem;
    font-weight: 600;
    margin-bottom: 32px;
    transition: opacity 0.2s;
}

.fpdou-back-btn:hover {
    opacity: 0.85;
}

.fpdou-detail-content {
    max-width: 800px;
    margin: 0 auto;
}

.fpdou-detail-header {
    text-align: center;
    margin-bottom: 32px;
}

.fpdou-detail-header h1 {
    font-size: 1.8rem;
    margin-bottom: 10px;
    color: var(--color-text);
}

.fpdou-detail-header p {
    color: var(--color-text-secondary);
    font-size: 1rem;
    max-width: 700px;
    margin: 0 auto;
}

.fpdou-detail-media {
    margin-bottom: 32px;
    text-align: center;
}

.fpdou-detail-media img {
    max-width: 100%;
    border-radius: 12px;
    box-shadow: 0 4px 24px var(--color-shadow);
}

.fpdou-detail-section {
    margin-bottom: 40px;
}

.fpdou-detail-section h2 {
    font-size: 1.3rem;
    margin-bottom: 16px;
    color: var(--color-accent);
}

.fpdou-detail-section p {
    line-height: 1.8;
    color: var(--color-text);
    margin-bottom: 16px;
}

.fpdou-single-img {
    display: block;
    max-width: 100%;
    border-radius: 8px;
    margin-top: 16px;
    box-shadow: 0 2px 12px var(--color-shadow);
}

.fpdou-results {
    display: flex;
    flex-direction: column;
    gap: 24px;
    margin-top: 20px;
}

.fpdou-result-item {
    text-align: center;
    margin: 0;
}

.fpdou-result-item img {
    max-width: 100%;
    border-radius: 8px;
    box-shadow: 0 2px 12px var(--color-shadow);
}

.fpdou-result-item figcaption {
    margin-top: 8px;
    font-size: 0.9rem;
    color: var(--color-text-secondary);
}

/* ===== Services ===== */
#services {
    padding: 60px 0;
}

.services-grid {
    display: grid;
    grid-template-columns: 1fr;
    gap: 32px;
    margin-top: 8px;
}

.service-category h3 {
    font-size: 1.05rem;
    font-weight: 700;
    margin-bottom: 10px;
    color: var(--color-accent);
    display: flex;
    align-items: center;
    gap: 8px;
}

.service-category h3 i {
    font-size: 0.9rem;
}

.service-category ul {
    list-style: none;
    padding-left: 32px;
}

.service-category li {
    font-size: 0.92rem;
    color: var(--color-text-light);
    padding: 3px 0;
    position: relative;
}

.service-category li::before {
    content: '•';
    position: absolute;
    left: -16px;
    color: var(--color-accent);
}

/* ===== Misc ===== */
#misc {
    padding: 60px 0;
    background: var(--color-section-bg);
}

.misc-grid {
    display: grid;
    grid-template-columns: 1fr;
    gap: 32px;
    margin-top: 8px;
}

.misc-category h3 {
    font-size: 1.05rem;
    font-weight: 700;
    margin-bottom: 10px;
    color: var(--color-accent);
    display: flex;
    align-items: center;
    gap: 8px;
}

.misc-category h3 i {
    font-size: 0.9rem;
}

.misc-category ul {
    list-style: none;
    padding-left: 32px;
}

.misc-category li {
    font-size: 0.92rem;
    color: var(--color-text-light);
    padding: 3px 0;
    position: relative;
}

.misc-category li::before {
    content: '•';
    position: absolute;
    left: -16px;
    color: var(--color-accent);
}

.misc-category li strong {
    color: var(--color-text);
}

/* ===== Footer ===== */
footer {
    padding: 32px 0;
    text-align: center;
    border-top: 1px solid var(--color-border);
}

footer p {
    font-size: 0.88rem;
    color: var(--color-text-light);
}

.footer-note {
    font-size: 0.8rem !important;
    margin-top: 4px;
    opacity: 0.7;
}

/* ===== Image Modal ===== */
.modal {
    display: none;
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background: rgba(0, 0, 0, 0.85);
    z-index: 2000;
    cursor: pointer;
    align-items: center;
    justify-content: center;
}

.modal.active {
    display: flex;
}

.modal-content {
    max-width: 90%;
    max-height: 90%;
    border-radius: 8px;
    box-shadow: 0 0 40px rgba(0, 0, 0, 0.5);
}

.modal-close {
    position: absolute;
    top: 20px;
    right: 30px;
    font-size: 2.5rem;
    color: #fff;
    cursor: pointer;
    transition: opacity 0.2s;
}

.modal-close:hover {
    opacity: 0.7;
}

/* ===== 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);
        flex-direction: column;
        padding: 16px 24px;
        gap: 12px;
        border-bottom: 1px solid var(--color-border);
        box-shadow: 0 4px 12px var(--color-shadow);
    }

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

    .nav-toggle {
        display: flex;
    }

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

    .header-photo img {
        width: 150px;
        height: 150px;
    }

    .header-info h1 {
        font-size: 1.8rem;
    }

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

    .pub-item {
        flex-direction: column;
        gap: 16px;
    }

    .pub-image {
        width: 100%;
        max-width: 400px;
    }

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

    .services-grid,
    .misc-grid {
        grid-template-columns: 1fr;
    }

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

@media (max-width: 480px) {
    .header-photo img {
        width: 120px;
        height: 120px;
    }

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

    .container {
        padding: 0 16px;
    }
}