:root {
    --bg: #fafafa;
    --surface: #ffffff;
    --surface-muted: #f4f4f6;
    --text: #171717;
    --text-soft: #374151;
    --muted: #6b7280;
    --border: #e5e7eb;
    --border-subtle: #f0f0f2;
    --accent: #2563eb;
    --accent-hover: #1d4ed8;
    --accent-soft: #eff6ff;

    --font-sans: Inter, ui-sans-serif, -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, sans-serif;

    /* Shared by existing photography page */
    --color-accent: #5b8def;
    --color-accent-light: #9fc2ff;
    --color-accent-dark: #3a6fd6;
    --shadow-md: 0 4px 16px rgba(0, 0, 0, 0.2);
    --shadow-xl: 0 16px 48px rgba(0, 0, 0, 0.4);
    --shadow-glow: 0 0 24px rgba(91, 141, 239, 0.14);
}

.home-page,
.home-page *,
.home-page *::before,
.home-page *::after {
    box-sizing: border-box;
}

html {
    scroll-behavior: smooth;
}

body.home-page {
    margin: 0;
    min-height: 100vh;
    background-color: var(--bg);
    color: var(--text);
    font-family: var(--font-sans);
    font-size: 16px;
    line-height: 1.7;
    -webkit-font-smoothing: antialiased;
    text-rendering: optimizeLegibility;
}

.home-page a {
    color: inherit;
    text-decoration: none;
    transition: color 150ms ease, text-decoration-color 150ms ease;
}

.home-page a:focus-visible,
.home-page button:focus-visible {
    outline: 2px solid var(--accent);
    outline-offset: 3px;
    border-radius: 3px;
}

.skip-link {
    position: fixed;
    top: 0.75rem;
    left: 0.75rem;
    z-index: 100;
    padding: 0.5rem 0.85rem;
    background: var(--text);
    color: #ffffff !important;
    font-size: 0.85rem;
    border-radius: 4px;
    transform: translateY(-150%);
    transition: transform 160ms ease;
}

.skip-link:focus {
    transform: translateY(0);
}

/* Page container: vertical academic structure (max 860px) */
.site-header,
.home-page main,
.site-footer {
    width: min(100% - 3rem, 860px);
    margin-inline: auto;
}

/* Header & Navigation */
.site-header {
    padding-block: 2.5rem 1.5rem;
    display: flex;
    align-items: baseline;
    justify-content: space-between;
    gap: 1.5rem;
}

.site-mark {
    font-size: 1.15rem;
    font-weight: 700;
    letter-spacing: -0.02em;
    color: var(--text);
}

.site-nav {
    display: flex;
    align-items: center;
    flex-wrap: wrap;
    gap: 1.35rem;
    font-size: 0.9rem;
    color: var(--muted);
}

.site-nav a {
    color: var(--muted);
    padding-block: 0.2rem;
}

.site-nav a:hover,
.site-nav a[aria-current="true"] {
    color: var(--text);
}

.nav-cv {
    opacity: 0.85;
}

/* Hero Section */
.hero {
    padding-block: 1.75rem 2.75rem;
}

.hero-content {
    display: flex;
    justify-content: space-between;
    align-items: flex-start;
    gap: 3rem;
}

.hero-text {
    flex: 1 1 auto;
    max-width: 650px;
}

.hero-name {
    font-size: 2.25rem;
    font-weight: 700;
    letter-spacing: -0.03em;
    line-height: 1.15;
    margin: 0 0 0.45rem;
    color: var(--text);
}

.hero-affiliation {
    font-size: 1.05rem;
    color: var(--text-soft);
    line-height: 1.55;
    margin: 0 0 0.85rem;
}

.hero-affiliation a {
    color: var(--text);
    text-decoration: underline;
    text-underline-offset: 3px;
    text-decoration-color: var(--border);
}

.hero-affiliation a:hover {
    text-decoration-color: var(--accent);
    color: var(--accent);
}

.hero-interests {
    font-size: 0.92rem;
    color: var(--accent);
    font-weight: 600;
    margin: 0 0 1rem;
    letter-spacing: 0.01em;
}

.hero-statement {
    font-size: 1rem;
    color: var(--text-soft);
    line-height: 1.7;
    margin: 0 0 1.5rem;
}

.hero-links {
    display: flex;
    flex-wrap: wrap;
    align-items: center;
    gap: 1.25rem;
    font-size: 0.9rem;
    font-weight: 500;
}

.hero-links a {
    color: var(--accent);
    display: inline-flex;
    align-items: center;
    gap: 0.25rem;
}

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

.link-arrow {
    display: inline-block;
    font-size: 0.82em;
    transition: transform 150ms ease;
}

a:hover .link-arrow {
    transform: translate(1px, -1px);
}

.hero-portrait {
    margin: 0;
    flex: 0 0 auto;
}

.hero-portrait img {
    width: 112px;
    height: 112px;
    display: block;
    object-fit: cover;
    object-position: center top;
    border-radius: 10px;
    border: 1px solid var(--border);
}

/* Sections */
.page-section {
    padding-block: 2.75rem 0;
    border-top: 1px solid var(--border);
    scroll-margin-top: 2rem;
}

.section-title {
    font-size: 1.3rem;
    font-weight: 650;
    letter-spacing: -0.02em;
    margin: 0 0 1.25rem;
    color: var(--text);
}

.section-body p {
    margin: 0 0 1.15rem;
    color: var(--text-soft);
    font-size: 1rem;
    line-height: 1.72;
    max-width: 760px;
}

.section-body p:last-child {
    margin-bottom: 0;
}

.section-body a {
    color: var(--text);
    text-decoration: underline;
    text-underline-offset: 3px;
    text-decoration-color: var(--border);
}

.section-body a:hover {
    color: var(--accent);
    text-decoration-color: var(--accent);
}

/* Currently / Research flow */
.research-flow {
    display: flex;
    flex-wrap: wrap;
    align-items: center;
    gap: 0.65rem 0.85rem;
    margin: 1.35rem 0 1.15rem;
    padding: 0.85rem 1.15rem;
    background: var(--surface);
    border: 1px solid var(--border);
    border-radius: 8px;
    font-size: 0.88rem;
}

.flow-node {
    font-weight: 550;
    color: var(--text);
}

.flow-arrow {
    color: var(--muted);
    font-size: 0.95rem;
    user-select: none;
}

.research-topics {
    margin: 0.75rem 0 0 !important;
    font-size: 0.88rem !important;
    color: var(--muted) !important;
}

.topics-label {
    color: var(--text-soft);
    font-weight: 550;
}

/* Projects List */
.projects-list {
    display: flex;
    flex-direction: column;
    gap: 1.85rem;
}

.project-item {
    padding-bottom: 1.85rem;
    border-bottom: 1px solid var(--border-subtle);
}

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

.project-header {
    display: flex;
    justify-content: space-between;
    align-items: baseline;
    gap: 1rem;
    margin-bottom: 0.45rem;
}

.project-title {
    font-size: 1.15rem;
    font-weight: 650;
    letter-spacing: -0.015em;
    margin: 0;
    color: var(--text);
}

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

.project-category {
    font-size: 0.82rem;
    color: var(--muted);
    font-weight: 500;
    white-space: nowrap;
}

.project-desc {
    font-size: 0.95rem;
    color: var(--text-soft);
    line-height: 1.68;
    margin: 0 0 0.65rem;
    max-width: 760px;
}

.project-attribution {
    font-size: 0.84rem;
    color: var(--muted);
    margin: 0 0 0.65rem;
}

.project-attribution a {
    color: var(--text-soft);
    text-decoration: underline;
    text-underline-offset: 2px;
}

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

.project-footer {
    display: flex;
    justify-content: space-between;
    align-items: center;
    flex-wrap: wrap;
    gap: 0.65rem 1.25rem;
    font-size: 0.84rem;
}

.project-stack {
    color: var(--muted);
}

.project-links {
    display: flex;
    align-items: center;
    gap: 1rem;
}

.project-links a {
    color: var(--accent);
    font-weight: 550;
    display: inline-flex;
    align-items: center;
    gap: 0.2rem;
}

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

/* Research Tool visual weight calibration */
.project-item-tool {
    padding-top: 0.15rem;
}

.project-item-tool .project-title {
    font-size: 1.08rem;
}

.project-item-tool .project-desc {
    font-size: 0.92rem;
}

/* Education */
.education-list {
    display: flex;
    flex-direction: column;
    gap: 1.35rem;
}

.education-item {
    display: flex;
    justify-content: space-between;
    align-items: flex-start;
    gap: 1.5rem;
}

.experience-item {
    display: flex;
    justify-content: space-between;
    align-items: center;
    gap: 1.5rem;
    padding-top: 1.35rem;
    border-top: 1px solid var(--border-subtle);
}

.edu-main {
    flex: 1 1 auto;
}

.edu-institution {
    font-size: 1.05rem;
    font-weight: 650;
    margin: 0;
    color: var(--text);
}

.edu-degree {
    font-size: 0.92rem;
    color: var(--text-soft);
    margin: 0.2rem 0 0;
}

.edu-meta {
    text-align: right;
    white-space: nowrap;
    font-size: 0.88rem;
}

.edu-date {
    display: block;
    color: var(--text-soft);
    font-variant-numeric: tabular-nums;
}

.edu-location {
    display: block;
    color: var(--muted);
    font-size: 0.82rem;
    margin-top: 0.15rem;
}

.edu-logo {
    flex: 0 0 176px;
    display: flex;
    align-items: center;
    justify-content: flex-end;
    min-height: 56px;
    padding: 0;
    border: 0;
    background: transparent;
}

.edu-logo img {
    display: block;
    max-width: 164px;
    max-height: 44px;
    width: auto;
    height: auto;
    object-fit: contain;
}

.edu-logo .fudan-logo {
    width: 150px;
    max-width: 150px;
    height: auto;
    max-height: 60px;
}

.edu-logo .whut-logo {
    max-width: 164px;
    max-height: 33px;
}

.experience-logo {
    flex-basis: 176px;
}

.experience-logo img {
    max-width: 150px;
    max-height: 32px;
}

/* Beyond Research */
.beyond-link-wrap {
    margin: 0.65rem 0 0 !important;
}

.text-link {
    display: inline-flex;
    align-items: center;
    gap: 0.35rem;
    color: var(--accent) !important;
    font-size: 0.9rem;
    font-weight: 550;
}

.text-link:hover {
    color: var(--accent-hover) !important;
}

.beyond-photo {
    margin: 1.5rem 0 0;
    max-width: 760px;
    overflow: hidden;
    border-radius: 8px;
    border: 1px solid var(--border);
    background: var(--surface-muted);
}

.beyond-photo img {
    width: 100%;
    max-height: 320px;
    object-fit: cover;
    display: block;
    filter: saturate(0.88);
    transition: filter 250ms ease;
}

.beyond-photo:hover img {
    filter: saturate(1);
}

/* Footer */
.site-footer {
    display: flex;
    justify-content: space-between;
    align-items: center;
    gap: 1rem;
    padding-block: 2rem 3.5rem;
    margin-top: 3.5rem;
    border-top: 1px solid var(--border);
    color: var(--muted);
    font-size: 0.82rem;
}

.site-footer p {
    margin: 0;
}

.footer-note {
    color: var(--muted);
}

/* Responsive Media Queries */
@media (max-width: 720px) {
    .site-header,
    .home-page main,
    .site-footer {
        width: min(100% - 2rem, 860px);
    }

    .site-header {
        flex-direction: column;
        align-items: flex-start;
        gap: 0.75rem;
        padding-block: 1.5rem 1rem;
    }

    .site-nav {
        gap: 0.55rem 0.75rem;
        font-size: 0.83rem;
    }

    .hero {
        padding-block: 1.25rem 2.25rem;
    }

    .hero-content {
        flex-direction: column-reverse;
        gap: 1.25rem;
    }

    .hero-portrait img {
        width: 96px;
        height: 96px;
    }

    .research-flow {
        flex-direction: column;
        align-items: flex-start;
        gap: 0.35rem;
        padding: 0.85rem 1rem;
    }

    .flow-arrow {
        transform: rotate(90deg);
        margin: 0.1rem 0 0.1rem 0.35rem;
    }

    .project-header {
        flex-direction: column;
        gap: 0.15rem;
    }

    .education-item {
        flex-direction: column;
        gap: 0.25rem;
    }

    .experience-item {
        align-items: flex-start;
        flex-direction: column;
        gap: 0.65rem;
    }

    .edu-meta {
        text-align: left;
    }

    .edu-logo,
    .experience-logo {
        flex: 0 0 auto;
        width: 176px;
        max-width: 100%;
        justify-content: flex-start;
    }
}

@media (max-width: 480px) {
    .site-footer {
        flex-direction: column;
        align-items: flex-start;
        gap: 0.35rem;
    }
}

@media print {
    body.home-page {
        background: white;
    }

    .site-header,
    .hero-links,
    .beyond-photo,
    .site-footer {
        display: none;
    }

    .hero,
    .page-section {
        padding-block: 1.5rem 0;
    }
}

@media (prefers-reduced-motion: reduce) {
    *,
    *::before,
    *::after {
        scroll-behavior: auto !important;
        animation-duration: 0.01ms !important;
        animation-iteration-count: 1 !important;
        transition-duration: 0.01ms !important;
    }
}

/* =========================================================
   Existing photography page compatibility styles
   ========================================================= */
.accent-dot { color: var(--color-accent); }
.accent-button {
    color: #dbe8ff;
    border: 1px solid rgba(91, 141, 239, 0.28);
    background: rgba(91, 141, 239, 0.1);
}

@keyframes page-fade-in {
    from { opacity: 1; }
    to { opacity: 0; }
}

.page-transition-overlay {
    position: fixed;
    inset: 0;
    z-index: 99999;
    pointer-events: none;
    background: #050505;
    opacity: 0;
    transition: opacity 0.4s ease;
}

.page-transition-overlay.is-leaving { opacity: 1; }
.page-transition-overlay.is-entering {
    opacity: 1;
    animation: page-fade-in 0.5s ease 0.1s forwards;
}

.photo-item {
    position: relative;
    overflow: hidden;
    background: rgba(255, 255, 255, 0.03);
    border: 1px solid rgba(255, 255, 255, 0.06);
    border-radius: 12px;
    box-shadow: var(--shadow-md);
    cursor: zoom-in;
    transition: transform 0.4s cubic-bezier(0.16, 1, 0.3, 1), box-shadow 0.4s ease, border-color 0.4s ease;
}

.photo-item::after {
    content: "";
    position: absolute;
    inset: 0;
    pointer-events: none;
    background: rgba(255, 255, 255, 0.04);
    opacity: 0;
    transition: opacity 0.3s ease;
}

.photo-item:hover {
    z-index: 10;
    border-color: rgba(91, 141, 239, 0.34);
    box-shadow: var(--shadow-xl), var(--shadow-glow);
    transform: translateY(-4px) scale(1.02);
}

.photo-item:hover::after { opacity: 1; }

.photo-item:focus-visible {
    outline: 2px solid var(--color-accent-light);
    outline-offset: 4px;
}

.photo-hero {
    min-height: clamp(390px, 62vh, 620px);
    position: relative;
    isolation: isolate;
    overflow: hidden;
    border: 1px solid rgba(255, 255, 255, 0.08);
    border-radius: 22px;
    box-shadow: 0 22px 70px rgba(0, 0, 0, 0.42);
}

.photo-hero::before {
    content: "";
    position: absolute;
    inset: 0;
    z-index: -1;
    background:
        linear-gradient(90deg, rgba(5, 5, 5, 0.78) 0%, rgba(5, 5, 5, 0.36) 44%, rgba(5, 5, 5, 0.05) 100%),
        linear-gradient(0deg, rgba(5, 5, 5, 0.72) 0%, rgba(5, 5, 5, 0.04) 52%, rgba(5, 5, 5, 0.24) 100%);
}

.photo-hero img {
    position: absolute;
    inset: 0;
    z-index: -2;
    width: 100%;
    height: 100%;
    object-fit: cover;
    object-position: center 46%;
    filter: saturate(1.05) contrast(1.02);
}

.photo-hero-copy { text-shadow: 0 2px 22px rgba(0, 0, 0, 0.72); }
.photo-hero-kicker {
    color: var(--color-accent-light) !important;
    letter-spacing: 0.16em;
    text-transform: uppercase;
}

.gallery-loader-button {
    border: 1px solid rgba(91, 141, 239, 0.22) !important;
    border-radius: 18px;
    background: rgba(91, 141, 239, 0.06) !important;
    cursor: pointer;
    transition: background 0.25s ease, border-color 0.25s ease, color 0.25s ease, transform 0.25s ease;
}

.gallery-loader-button:hover,
.gallery-loader-button:focus-visible {
    background: rgba(91, 141, 239, 0.12) !important;
    border-color: rgba(91, 141, 239, 0.42) !important;
    color: #eef4ff;
    transform: translateY(-2px);
}

.gallery-loader-icon {
    width: 2rem;
    height: 2rem;
    position: relative;
    border: 1px solid rgba(159, 194, 255, 0.26);
    border-radius: 0.7rem;
    background: linear-gradient(135deg, rgba(159, 194, 255, 0.16), rgba(255, 255, 255, 0.03));
}

.gallery-loader-icon::before,
.gallery-loader-icon::after {
    content: "";
    position: absolute;
    inset: 0.55rem;
    border: 1.5px solid rgba(159, 194, 255, 0.82);
    border-radius: 999px;
}

.gallery-loader-icon::after {
    inset: 0.78rem;
    border-color: rgba(240, 179, 106, 0.74);
}

.gallery-loader-icon.is-spinning { animation: loader-rotate 1.1s linear infinite; }
@keyframes loader-rotate { to { transform: rotate(360deg); } }

.zoom-icon-stack { display: grid; place-items: center; }
.zoom-icon-stack svg { grid-area: 1 / 1; }
.zoom-out-icon,
#lightbox-zoom.is-zoomed .zoom-in-icon { display: none; }
#lightbox-zoom.is-zoomed .zoom-out-icon { display: block; }
#lightbox { z-index: 9999; }

@media (max-width: 640px) {
    .photo-hero {
        min-height: 500px;
        border-radius: 18px;
    }

    .photo-hero::before {
        background: linear-gradient(0deg, rgba(5, 5, 5, 0.86) 0%, rgba(5, 5, 5, 0.5) 42%, rgba(5, 5, 5, 0.18) 72%, rgba(5, 5, 5, 0.38) 100%);
    }

    .photo-hero img { object-position: 48% center; }
}