/* A compact, editorial layout for an academic homepage. */
:root {
    --primary-color: #205b93;
    --secondary-color: #16446f;
    --text-color: #242a30;
    --light-text: #59636e;
    --bg-color: #fff;
    --light-bg: #f6f8fa;
    --border-color: #dfe5eb;
    --font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial, sans-serif;
    --container-width: 1040px;
    --header-height: 68px;
}

* { margin: 0; padding: 0; box-sizing: border-box; }
html { scroll-behavior: smooth; scroll-padding-top: calc(var(--header-height) + 20px); }
body { font-family: var(--font-family); line-height: 1.7; color: var(--text-color); background: var(--bg-color); -webkit-font-smoothing: antialiased; }
a { color: var(--primary-color); text-decoration-thickness: 1px; text-underline-offset: 3px; }
a:hover { color: var(--secondary-color); }
button, summary, a { -webkit-tap-highlight-color: transparent; }
button { font: inherit; cursor: pointer; }
:focus-visible { outline: 3px solid var(--primary-color); outline-offset: 5px; border-radius: 3px; }
[tabindex="-1"]:focus { outline: none; }
[hidden] { display: none !important; }
ul { list-style: none; }
img { display: block; max-width: 100%; height: auto; }
h1, h2, h3 { line-height: 1.3; }
p { overflow-wrap: break-word; }
.container { width: 100%; max-width: var(--container-width); margin-inline: auto; padding-inline: 20px; }
.section { padding-block: 44px; }
.section + .section > .container { border-top: 1px solid var(--border-color); padding-top: 36px; }
.section + .section { padding-top: 0; }
.section-title { font-size: 1.65rem; font-weight: 650; letter-spacing: -0.035em; margin-bottom: 24px; }
.section-heading { display: flex; align-items: baseline; justify-content: space-between; gap: 16px; }
.section-note { font-size: .85rem; color: var(--light-text); white-space: nowrap; }
.skip-link { position: fixed; top: 10px; left: 16px; z-index: 1100; padding: 10px 16px; background: white; transform: translateY(-160%); }
.skip-link:focus { transform: translateY(0); }

/* Navigation stays usable when JavaScript is unavailable. */
.site-header { position: sticky; top: 0; z-index: 1000; background: var(--bg-color); border-bottom: 1px solid var(--border-color); }
.main-nav { min-height: var(--header-height); display: flex; align-items: center; justify-content: space-between; gap: 24px; }
.logo { font-size: 1.1rem; font-weight: 700; letter-spacing: -.025em; color: var(--text-color); white-space: nowrap; text-decoration: none; }
.nav-links { display: flex; align-items: center; gap: 20px; }
.nav-links a { display: flex; align-items: center; min-height: 44px; font-size: .85rem; font-weight: 500; color: var(--light-text); text-decoration: none; border-bottom: 2px solid transparent; }
.nav-links a:hover, .nav-links a[aria-current="location"] { color: var(--primary-color); border-bottom-color: var(--primary-color); }
.mobile-menu-toggle { display: none; width: 44px; height: 44px; border: 1px solid var(--border-color); border-radius: 6px; background: white; align-items: center; justify-content: center; flex-direction: column; gap: 4px; }
.mobile-menu-toggle span { width: 18px; height: 2px; background: var(--text-color); transition: transform .18s ease, opacity .18s ease; }
.mobile-menu-toggle[aria-expanded="true"] span:nth-child(1) { transform: translateY(6px) rotate(45deg); }
.mobile-menu-toggle[aria-expanded="true"] span:nth-child(2) { opacity: 0; }
.mobile-menu-toggle[aria-expanded="true"] span:nth-child(3) { transform: translateY(-6px) rotate(-45deg); }

/* Profile and biography share one compact introduction. */
.hero-section { padding-block: 52px 36px; background: var(--light-bg); border-bottom: 1px solid var(--border-color); }
.hero-content { display: grid; grid-template-columns: 200px minmax(0, 1fr); align-items: center; gap: 40px; }
.profile-image img { width: 200px; height: 200px; object-fit: cover; border-radius: 50%; }
.eyebrow { font-size: .78rem; font-weight: 600; letter-spacing: .035em; color: var(--light-text); margin-bottom: 10px; }
.profile-info h1 { font-size: clamp(2rem, 4vw, 2.8rem); font-weight: 700; letter-spacing: -.045em; margin-bottom: 8px; }
.chinese-name { display: inline-block; font-size: .58em; font-weight: 400; letter-spacing: .02em; color: var(--light-text); margin-left: 8px; }
.subtitle { color: var(--light-text); font-size: .98rem; }
.research-focus { margin-top: 10px; font-size: 1.05rem; }
.social-links { display: flex; flex-wrap: wrap; align-items: center; gap: 8px 12px; margin-top: 18px; }
.btn { min-height: 44px; display: inline-flex; align-items: center; justify-content: center; gap: 10px; padding: 8px 15px; border: 1px solid transparent; border-radius: 5px; text-decoration: none; font-size: .88rem; font-weight: 600; transition: background-color .18s ease, border-color .18s ease; }
.btn-primary { background: var(--primary-color); color: white; }
.btn-primary:hover { background: var(--secondary-color); color: white; }
.btn-outline { border-color: var(--border-color); background: white; }
.btn-outline:hover { border-color: var(--primary-color); background: #edf3f9; }
.secondary-link { display: inline-flex; align-items: center; min-height: 44px; padding-inline: 4px; font-size: .88rem; color: var(--light-text); }
.contact-links { display: flex; flex-wrap: wrap; align-items: center; gap: 0 16px; margin-top: 6px; }
.email-link { display: inline-flex; align-items: center; min-height: 44px; font-size: .88rem; }
abbr[title] { text-decoration: none; }
.biography { max-width: 75ch; margin-top: 28px; font-size: .96rem; }
.biography p + p { margin-top: 12px; }

/* Publication text leads; figures are supplementary links to original images. */
.publication-list { display: flex; flex-direction: column; }
.publication-item { display: grid; grid-template-columns: minmax(0, 1fr) 280px; align-items: center; gap: 32px; padding-block: 26px; }
.publication-item:first-child { padding-top: 0; }
.publication-item:last-child { padding-bottom: 0; }
.publication-item + .publication-item { border-top: 1px solid var(--border-color); }
.pub-meta { color: var(--primary-color); font-size: .78rem; font-weight: 650; letter-spacing: .015em; margin-bottom: 8px; }
.badge { display: inline-block; color: var(--secondary-color); background: #eaf1f8; border-radius: 4px; padding: 3px 8px; margin-bottom: 9px; font-size: .73rem; font-weight: 600; }
.pub-content { min-width: 0; }
.pub-content h3 { font-size: 1.17rem; letter-spacing: -.015em; margin-bottom: 10px; }
.pub-content h3 a { color: var(--text-color); text-decoration: none; }
.pub-content h3 a:hover { color: var(--primary-color); text-decoration: underline; }
.authors { font-size: .86rem; color: var(--light-text); margin-bottom: 8px; }
.authors strong { color: var(--text-color); }
.pub-summary { font-size: .9rem; color: var(--light-text); }
.pub-links { display: flex; gap: 20px; margin-top: 8px; }
.pub-links a { display: inline-flex; align-items: center; min-height: 44px; gap: 6px; font-size: .85rem; font-weight: 600; }
.pub-image { display: block; text-decoration: none; }
.pub-image img { width: 100%; height: 180px; object-fit: contain; padding: 8px; background: white; border: 1px solid var(--border-color); border-radius: 5px; }
.pub-image:hover img { border-color: var(--primary-color); }
.figure-caption { display: block; margin-top: 5px; color: var(--light-text); font-size: .75rem; text-align: right; }

.news-list { max-width: 90ch; }
.news-list li { display: grid; grid-template-columns: 88px minmax(0, 1fr); gap: 16px; align-items: baseline; font-size: .9rem; }
.news-list li + li { margin-top: 14px; }
.date { color: var(--light-text); font-size: .8rem; font-variant-numeric: tabular-nums; white-space: nowrap; }
.research-grid { display: grid; grid-template-columns: repeat(2, minmax(0, 1fr)); gap: 32px; }
.research-item { padding-left: 18px; border-left: 2px solid var(--border-color); }
.research-item h3 { font-size: 1rem; margin-bottom: 8px; }
.research-item p { color: var(--light-text); font-size: .9rem; }
.timeline { border-left: 1px solid var(--border-color); padding-left: 22px; }
.timeline-item { display: grid; grid-template-columns: 165px minmax(0, 1fr); gap: 24px; position: relative; }
.timeline-item + .timeline-item { margin-top: 24px; }
.timeline-item::before { content: ''; position: absolute; left: -27px; top: 7px; width: 9px; height: 9px; border-radius: 50%; background: var(--primary-color); border: 2px solid white; }
.timeline-date { font-size: .82rem; color: var(--light-text); font-variant-numeric: tabular-nums; }
.timeline-content h3 { font-size: 1rem; margin-bottom: 4px; }
.timeline-content p { color: var(--light-text); font-size: .9rem; }

.projects-grid { display: grid; grid-template-columns: repeat(3, minmax(0, 1fr)); gap: 16px; }
.project-card { padding: 20px; border: 1px solid var(--border-color); border-radius: 6px; display: flex; flex-direction: column; min-width: 0; }
.project-card .project-category { font-size: .72rem; color: var(--primary-color); margin-bottom: 10px; }
.project-card h3 { font-size: 1rem; margin-bottom: 10px; }
.project-card p { color: var(--light-text); font-size: .85rem; }
.project-links { margin-top: auto; padding-top: 12px; }
.project-links a { display: inline-flex; min-height: 44px; align-items: center; gap: 6px; font-size: .85rem; }
.more-content { margin-top: 20px; }
.more-content summary { cursor: pointer; width: fit-content; min-height: 44px; padding: 8px 0; color: var(--primary-color); font-size: .9rem; font-weight: 600; }
.detail-count { color: var(--light-text); font-size: .78rem; font-weight: 400; margin-left: 8px; }
.more-content[open] summary { margin-bottom: 16px; }
.award-group { display: grid; grid-template-columns: 110px minmax(0, 1fr); gap: 24px; }
.award-group + .award-group { margin-top: 18px; }
.award-group h3 { font-size: .85rem; line-height: 1.7; font-weight: 500; color: var(--light-text); }
.awards-list { font-size: .9rem; }
.awards-list li + li { margin-top: 10px; }

.site-footer { padding-block: 24px; border-top: 1px solid var(--border-color); color: var(--light-text); font-size: .8rem; }
.site-footer a { margin-left: 16px; display: inline-block; padding-block: 8px; }
#back-to-top { position: fixed; bottom: 20px; right: 20px; width: 44px; height: 44px; border: 1px solid var(--border-color); border-radius: 50%; background: white; color: var(--primary-color); font-size: 1.25rem; box-shadow: 0 2px 8px #242a3010; z-index: 900; }
#back-to-top:hover { background: var(--light-bg); border-color: var(--primary-color); }

@media (max-width: 900px) {
    .nav-links { gap: 12px; }
    .hero-content { grid-template-columns: 180px minmax(0, 1fr); gap: 28px; }
    .profile-image img { width: 180px; height: 180px; }
    .publication-item { grid-template-columns: minmax(0, 1fr) 220px; gap: 24px; }
    .projects-grid { grid-template-columns: repeat(2, minmax(0, 1fr)); }
}

@media (max-width: 760px) {
    :root { --header-height: 60px; }
    .site-header:not(.is-enhanced) { position: static; }
    .main-nav { flex-wrap: wrap; gap: 0; padding-block: 8px; }
    .nav-links { width: 100%; flex-wrap: wrap; gap: 0 16px; }
    .site-header.is-enhanced .main-nav { flex-wrap: nowrap; padding-block: 0; }
    .is-enhanced .mobile-menu-toggle { display: flex; flex-shrink: 0; }
    .is-enhanced .nav-links { display: none; position: absolute; top: 100%; left: 0; right: 0; background: white; border-bottom: 1px solid var(--border-color); padding: 12px 20px; max-height: calc(100dvh - var(--header-height)); overflow-y: auto; }
    .is-enhanced .nav-links.active { display: flex; flex-direction: column; align-items: stretch; gap: 0; }
    .is-enhanced .nav-links a { padding: 8px 12px; border: 0; border-radius: 4px; }
    .is-enhanced .nav-links a[aria-current="location"] { background: #eaf1f8; }
    .hero-section { padding-block: 32px; }
    .hero-content { grid-template-columns: 140px minmax(0, 1fr); gap: 24px; }
    .profile-image img { width: 140px; height: 140px; }
    .section { padding-block: 36px; }
    .section + .section > .container { padding-top: 32px; }
    .section-title { font-size: 1.5rem; margin-bottom: 20px; }
}

@media (max-width: 600px) {
    .hero-section { padding-block: 24px; }
    .hero-content { grid-template-columns: minmax(0, 1fr); gap: 20px; }
    .profile-image img { width: 128px; height: 128px; }
    .eyebrow { font-size: .72rem; margin-bottom: 8px; }
    .profile-info h1 { font-size: 2rem; }
    .subtitle, .biography { font-size: .9rem; }
    .research-focus { font-size: .98rem; }
    .social-links { gap: 6px 10px; margin-top: 14px; }
    .btn { padding-inline: 12px; }
    .biography { margin-top: 16px; }
    .publication-item { grid-template-columns: minmax(0, 1fr); gap: 14px; }
    .pub-content h3 { font-size: 1.1rem; }
    .pub-image { width: min(280px, 100%); }
    .pub-image img { height: 148px; }
    .news-list li { grid-template-columns: minmax(0, 1fr); gap: 2px; }
    .news-list li + li { margin-top: 18px; }
    .research-grid, .projects-grid { grid-template-columns: minmax(0, 1fr); gap: 20px; }
    .timeline-item { grid-template-columns: minmax(0, 1fr); gap: 5px; }
    .award-group { grid-template-columns: minmax(0, 1fr); gap: 8px; }
    .award-group h3 { font-weight: 600; }
    .site-footer { padding-bottom: 72px; }
    #back-to-top { bottom: max(16px, env(safe-area-inset-bottom)); right: 16px; }
}

@media (prefers-reduced-motion: reduce) {
    html { scroll-behavior: auto; }
    *, *::before, *::after { transition: none !important; animation: none !important; }
}