/* Prof. Puneet Mahajan — responsive academic website */
:root {
  --ink: #182230;
  --ink-soft: #475467;
  --muted: #667085;
  --line: #e4e7ec;
  --surface: #ffffff;
  --surface-soft: #f7f8fa;
  --surface-tint: #f9f5f5;
  --nav: #111827;
  --accent: #a61b1b;
  --accent-dark: #7f1414;
  --accent-soft: #fbeaea;
  --max-width: 1180px;
  --radius: 16px;
  --shadow: 0 12px 32px rgba(16, 24, 40, .08);
}

* { box-sizing: border-box; }
html { scroll-behavior: smooth; }
body {
  margin: 0;
  color: var(--ink);
  background: var(--surface);
  font-family: Inter, ui-sans-serif, -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Helvetica, Arial, sans-serif;
  font-size: 16px;
  line-height: 1.65;
  -webkit-font-smoothing: antialiased;
}
img, video { max-width: 100%; }
a { color: var(--accent); text-underline-offset: 3px; }
a:hover { color: var(--accent-dark); }
button, input { font: inherit; }
button, a { -webkit-tap-highlight-color: transparent; }
::selection { background: #f4caca; color: #381010; }

.skip-link { position: fixed; left: 1rem; top: -100px; z-index: 9999; background: #fff; color: #111827; padding: .75rem 1rem; border-radius: 8px; box-shadow: var(--shadow); }
.skip-link:focus { top: 1rem; }
.container { width: min(calc(100% - 40px), var(--max-width)); margin-inline: auto; }
.section { padding: 78px 0; }
.section-muted { background: var(--surface-soft); border-block: 1px solid #eef0f2; }
.section-kicker, .eyebrow { margin: 0 0 .65rem; color: var(--accent); font-size: .78rem; font-weight: 800; letter-spacing: .13em; text-transform: uppercase; }
h1, h2, h3, h4 { margin-top: 0; line-height: 1.2; letter-spacing: -.02em; color: var(--ink); }
h1 { font-size: clamp(2.35rem, 5vw, 4.45rem); }
h2 { font-size: clamp(1.75rem, 3vw, 2.55rem); }
h3 { font-size: 1.2rem; }
p { margin-top: 0; }
.prose p:last-child { margin-bottom: 0; }
.section-heading { display: flex; justify-content: space-between; gap: 2rem; align-items: end; margin-bottom: 32px; }
.section-heading h2 { margin-bottom: 0; }
.text-link { display: inline-flex; gap: .45rem; align-items: center; font-weight: 700; text-decoration: none; white-space: nowrap; }

/* Header */
.site-header { position: sticky; top: 0; z-index: 1000; background: rgba(17,24,39,.97); border-bottom: 1px solid rgba(255,255,255,.1); backdrop-filter: blur(12px); }
.nav-container { width: min(calc(100% - 36px), 1240px); margin-inline: auto; min-height: 72px; display: flex; align-items: center; gap: 22px; }
.site-brand { min-width: 210px; display: flex; flex-direction: column; color: #fff; text-decoration: none; line-height: 1.15; }
.site-brand:hover { color: #fff; }
.brand-name { font-size: 1rem; font-weight: 800; letter-spacing: .01em; }
.brand-affiliation { margin-top: 4px; color: #cbd5e1; font-size: .72rem; letter-spacing: .04em; }
.site-nav { margin-left: auto; }
.main-menu { list-style: none; display: flex; align-items: center; gap: 2px; margin: 0; padding: 0; }
.main-menu a { display: block; padding: 10px 9px; border-radius: 7px; color: #e5e7eb; text-decoration: none; font-size: .84rem; font-weight: 650; white-space: nowrap; transition: background .2s ease, color .2s ease; }
.main-menu a:hover, .main-menu a[aria-current="page"] { color: #fff; background: rgba(255,255,255,.09); }
.main-menu a[aria-current="page"] { box-shadow: inset 0 -2px var(--accent); }
.nav-toggle { display: none; width: 44px; height: 44px; padding: 10px; margin-left: auto; border: 0; border-radius: 8px; color: #fff; background: transparent; cursor: pointer; }
.nav-toggle span { display: block; height: 2px; margin: 5px 0; border-radius: 2px; background: currentColor; transition: transform .2s ease, opacity .2s ease; }
.nav-toggle[aria-expanded="true"] span:nth-child(1) { transform: translateY(7px) rotate(45deg); }
.nav-toggle[aria-expanded="true"] span:nth-child(2) { opacity: 0; }
.nav-toggle[aria-expanded="true"] span:nth-child(3) { transform: translateY(-7px) rotate(-45deg); }

/* Hero */
.hero { color: #fff; background: radial-gradient(circle at 85% 15%, rgba(166,27,27,.32), transparent 32%), linear-gradient(125deg, #111827 0%, #182230 62%, #291717 100%); border-bottom: 5px solid var(--accent); }
.hero-inner { width: min(calc(100% - 40px), var(--max-width)); margin: auto; min-height: 620px; padding: 90px 0; display: grid; grid-template-columns: minmax(0, 1.25fr) minmax(300px, .75fr); align-items: center; gap: clamp(50px, 7vw, 100px); }
.hero .eyebrow { color: #f6b9b9; }
.hero h1 { color: #fff; margin-bottom: 14px; }
.hero-role { margin-bottom: 24px; color: #e5e7eb; font-size: clamp(1.08rem, 2vw, 1.3rem); font-weight: 650; }
.hero-summary { max-width: 720px; margin-bottom: 34px; color: #d1d5db; font-size: clamp(1.05rem, 1.8vw, 1.22rem); line-height: 1.75; }
.hero-actions { display: flex; flex-wrap: wrap; gap: 12px; }
.button { display: inline-flex; justify-content: center; align-items: center; min-height: 46px; padding: 11px 18px; border: 1px solid transparent; border-radius: 9px; font-weight: 750; text-decoration: none; transition: transform .16s ease, background .16s ease, border-color .16s ease; }
.button:hover { transform: translateY(-1px); }
.button-primary { background: var(--accent); color: #fff; }
.button-primary:hover { background: var(--accent-dark); color: #fff; }
.button-secondary { background: #fff; color: var(--ink); border-color: #fff; }
.button-secondary:hover { color: var(--ink); background: #f3f4f6; }
.button-ghost { color: #fff; border-color: #6b7280; background: transparent; }
.button-ghost:hover { color: #fff; background: rgba(255,255,255,.08); }
.profile-links { margin-top: 28px; display: flex; flex-wrap: wrap; gap: 8px 18px; }
.profile-links a { color: #d1d5db; font-size: .88rem; font-weight: 650; text-decoration: none; border-bottom: 1px solid #6b7280; }
.profile-links a:hover { color: #fff; border-bottom-color: #fff; }
.hero-portrait-wrap { display: flex; justify-content: center; }
.hero-portrait-card { width: min(100%, 340px); padding: 18px; border: 1px solid rgba(255,255,255,.16); border-radius: 24px; background: rgba(255,255,255,.07); box-shadow: 0 28px 70px rgba(0,0,0,.27); }
.hero-portrait { width: 100%; aspect-ratio: 4 / 5; display: block; object-fit: cover; object-position: center top; border-radius: 16px; background: #fff; }
.hero-contact-line { display: grid; gap: 2px; padding: 16px 4px 2px; color: #cbd5e1; font-size: .84rem; }
.hero-contact-line a { color: #fff; text-decoration: none; }

/* Homepage sections */
.split-intro { display: grid; grid-template-columns: .75fr 1.25fr; gap: clamp(40px, 7vw, 100px); }
.split-intro h2 { margin-bottom: 0; }
.lead-copy { color: var(--ink-soft); font-size: 1.08rem; }
.research-card-grid { display: grid; grid-template-columns: repeat(3, 1fr); gap: 22px; }
.research-card { overflow: hidden; background: #fff; border: 1px solid var(--line); border-radius: var(--radius); box-shadow: 0 5px 18px rgba(16,24,40,.04); }
.research-card img { width: 100%; aspect-ratio: 16 / 10; object-fit: cover; display: block; background: #eef2f6; }
.research-card-body { padding: 22px; }
.research-card-body h3 { margin-bottom: 9px; }
.research-card-body p { margin: 0; color: var(--ink-soft); font-size: .94rem; }
.profile-grid { display: grid; grid-template-columns: repeat(3,1fr); gap: 22px; }
.profile-card { padding: 26px; border: 1px solid var(--line); border-top: 3px solid var(--accent); border-radius: var(--radius); background: #fff; }
.timeline-list { list-style: none; padding: 0; margin: 0 0 18px; }
.timeline-list li { padding: 11px 0; border-bottom: 1px solid var(--line); }
.timeline-list li:last-child { border-bottom: 0; }
.timeline-list strong, .timeline-list span { display: block; }
.timeline-list span { margin-top: 2px; color: var(--muted); font-size: .88rem; }
.publication-feature-grid { display: grid; grid-template-columns: repeat(3, 1fr); gap: 22px; }
.publication-feature { padding: 26px; border-radius: var(--radius); background: #fff; border: 1px solid var(--line); }
.publication-year { display: inline-block; margin-bottom: 12px; color: var(--accent); font-size: .78rem; font-weight: 800; }
.publication-feature h3 { font-size: 1.05rem; line-height: 1.45; }
.publication-feature p { color: var(--ink-soft); font-size: .9rem; }
.publication-feature a { font-weight: 700; text-decoration: none; }
.group-callout-section { padding-top: 62px; padding-bottom: 62px; }
.group-callout { display: flex; justify-content: space-between; align-items: center; gap: 40px; padding: 38px 42px; border-radius: 20px; background: #171d27; color: #d1d5db; }
.group-callout h2 { color: #fff; margin-bottom: 10px; }
.group-callout p:last-child { margin-bottom: 0; }

/* Page hero */
.page-hero { padding: 66px 0; color: #fff; background: linear-gradient(120deg, #151b26, #202938 70%, #371a1a); border-bottom: 4px solid var(--accent); }
.page-hero .section-kicker { color: #f6b9b9; }
.page-hero h1 { margin: 0 0 15px; color: #fff; font-size: clamp(2.2rem, 4.4vw, 3.5rem); }
.page-hero p { max-width: 850px; margin-bottom: 0; color: #d1d5db; font-size: 1.08rem; }
.page-hero-links { display: flex; flex-wrap: wrap; gap: 18px; margin-top: 22px; }
.page-hero-links a { color: #fff; font-weight: 700; text-decoration: none; }

/* Research */
.research-detail-list { display: grid; gap: 82px; }
.research-detail { display: grid; grid-template-columns: .82fr 1.18fr; gap: clamp(32px, 5vw, 70px); align-items: start; }
.research-detail:nth-child(even) .research-detail-copy { order: 2; }
.research-detail-copy { position: sticky; top: 108px; }
.theme-number { display: inline-flex; align-items: center; justify-content: center; width: 42px; height: 42px; margin-bottom: 16px; border-radius: 50%; background: var(--accent-soft); color: var(--accent); font-size: .78rem; font-weight: 850; }
.research-detail-copy h2 { font-size: clamp(1.55rem, 2.5vw, 2.15rem); }
.research-detail-copy p { color: var(--ink-soft); }
.contributors { padding-top: 14px; border-top: 1px solid var(--line); font-size: .9rem; }
.research-gallery { display: grid; gap: 14px; }
.research-gallery-two { grid-template-columns: 1fr 1fr; }
.research-gallery-three { grid-template-columns: repeat(3, 1fr); }
.research-gallery figure { margin: 0; overflow: hidden; border: 1px solid var(--line); border-radius: 14px; background: #fff; box-shadow: 0 4px 16px rgba(16,24,40,.05); }
.research-gallery img { width: 100%; min-height: 260px; max-height: 430px; display: block; object-fit: contain; background: #f4f5f7; cursor: zoom-in; transition: transform .2s ease, background .2s ease; }
.research-gallery img:hover, .research-gallery img:focus { transform: scale(1.018); background: #fff; }
.research-gallery-three img { min-height: 210px; }
.research-gallery figcaption { padding: 10px 12px; color: var(--muted); border-top: 1px solid var(--line); font-size: .82rem; }

/* Team */
.team-page { max-width: 1220px; }
.search-panel { max-width: 760px; margin: 0 auto 28px; padding: 22px; border: 1px solid var(--line); border-radius: 14px; background: var(--surface-soft); }
.search-panel label, .publication-search label, .field-label { display: block; margin-bottom: 8px; color: var(--ink); font-size: .88rem; font-weight: 750; }
.search-panel input, .publication-search input, .search-bar { width: 100%; min-height: 48px; padding: 11px 14px; border: 1px solid #cbd0d8; border-radius: 9px; background: #fff; color: var(--ink); outline: none; }
.search-panel input:focus, .publication-search input:focus, .search-bar:focus { border-color: var(--accent); box-shadow: 0 0 0 3px rgba(166,27,27,.1); }
.search-status { margin: 9px 0 0; color: var(--muted); font-size: .84rem; }
.section-jump { display: flex; flex-wrap: wrap; justify-content: center; gap: 8px; margin-bottom: 52px; }
.section-jump a { padding: 7px 11px; border: 1px solid var(--line); border-radius: 999px; color: var(--ink-soft); background: #fff; font-size: .82rem; font-weight: 700; text-decoration: none; }
.section-jump a:hover { border-color: var(--accent); color: var(--accent); }
.team-section { margin-bottom: 68px; scroll-margin-top: 100px; }
.subsection-heading { display: flex; align-items: center; gap: 10px; margin-bottom: 24px; padding-bottom: 12px; border-bottom: 1px solid var(--line); }
.subsection-heading h2 { margin: 0; font-size: 1.65rem; }
.subsection-heading span { display: inline-block; margin-left: 7px; vertical-align: middle; padding: 3px 8px; border-radius: 999px; background: var(--accent-soft); color: var(--accent); font-size: .65rem; text-transform: uppercase; letter-spacing: .08em; }
.team-grid { display: grid; grid-template-columns: repeat(2, minmax(0, 1fr)); gap: 18px; }
.member-card { min-width: 0; display: grid; grid-template-columns: 128px minmax(0,1fr); gap: 20px; padding: 20px; border: 1px solid var(--line); border-radius: 14px; background: #fff; box-shadow: 0 4px 14px rgba(16,24,40,.04); }
.member-card > img { width: 128px; height: 150px; border-radius: 10px; object-fit: cover; object-position: center top; background: #f0f2f4; }
.member-text { min-width: 0; }
.member-card h3 { margin: 0 0 8px; font-size: 1.05rem; line-height: 1.35; font-weight: 750; text-transform: none; }
.member-card p { margin: 4px 0; color: var(--ink-soft); font-size: .84rem; line-height: 1.45; overflow-wrap: anywhere; }
.member-card p strong { color: var(--ink); }
.social-icons { display: flex; flex-wrap: wrap; gap: 6px; margin-top: 11px; }
.social-icons a { display: inline-flex; padding: 4px 7px; border: 1px solid var(--line); border-radius: 6px; color: var(--ink-soft); background: #fff; font-size: .7rem; font-weight: 750; line-height: 1.3; text-decoration: none; }
.social-icons a:hover { border-color: var(--accent); color: var(--accent); }

/* Publications */
.publications-browser { max-width: 980px; }
.publication-toolbar { display: grid; grid-template-columns: auto minmax(300px, 1fr); gap: 28px; align-items: end; margin-bottom: 8px; }
.toggle-btns { display: flex; gap: 8px; }
.toggle-btns button, .pagination-controls button { min-height: 42px; padding: 8px 13px; border: 1px solid #cfd4dc; border-radius: 8px; background: #fff; color: var(--ink); cursor: pointer; font-weight: 700; }
.toggle-btns button:hover, .pagination-controls button:hover:not(:disabled) { border-color: var(--accent); color: var(--accent); }
.toggle-btns button.active-toggle { border-color: var(--accent); background: var(--accent); color: #fff; }
.publication-list { margin-top: 28px; border-top: 1px solid var(--line); }
.publication-entry { display: grid; grid-template-columns: 44px minmax(0, 1fr); gap: 16px; padding: 23px 0; border-bottom: 1px solid var(--line); }
.publication-index { width: 38px; height: 38px; display: flex; align-items: center; justify-content: center; border-radius: 50%; background: var(--surface-soft); color: var(--muted); font-size: .75rem; font-weight: 800; }
.publication-content h2 { margin: 0 0 7px; font-size: 1.02rem; line-height: 1.45; }
.publication-authors { margin: 0 0 5px; color: var(--ink-soft); font-size: .88rem; }
.publication-meta { margin: 0; color: var(--muted); font-size: .84rem; }
.publication-link { display: inline-block; margin-top: 8px; font-size: .8rem; font-weight: 750; text-decoration: none; }
.pagination-controls { display: flex; flex-wrap: wrap; justify-content: center; gap: 7px; margin-top: 30px; }
.pagination-controls button[aria-current="page"] { background: var(--accent); border-color: var(--accent); color: #fff; }
.pagination-controls button:disabled { opacity: .42; cursor: default; }
.empty-state { padding: 44px 0; color: var(--muted); text-align: center; border-bottom: 1px solid var(--line); }

/* Courses */
.course-grid { display: grid; grid-template-columns: repeat(3, 1fr); gap: 16px; }
.course-card { min-height: 145px; padding: 24px; border: 1px solid var(--line); border-radius: 14px; background: #fff; }
.course-code { display: inline-block; margin-bottom: 22px; padding: 4px 8px; border-radius: 6px; background: var(--accent-soft); color: var(--accent); font-size: .76rem; font-weight: 850; letter-spacing: .05em; }
.course-card h2 { margin: 0; font-size: 1.02rem; line-height: 1.45; }

/* Facilities */
.facilities-grid { max-width: 960px; display: grid; gap: 16px; }
.facility-card { display: grid; grid-template-columns: 78px minmax(0,1fr); gap: 22px; align-items: start; padding: 26px; border: 1px solid var(--line); border-radius: 14px; background: #fff; }
.facility-mark { width: 68px; min-height: 54px; display: flex; align-items: center; justify-content: center; padding: 7px; border-radius: 10px; background: #1f2937; color: #fff; font-weight: 850; letter-spacing: .04em; }
.facility-card h2 { margin-bottom: 6px; font-size: 1.2rem; }
.facility-card p { margin: 0; color: var(--ink-soft); }

/* Contact */
.contact-grid { max-width: 1040px; display: grid; grid-template-columns: .86fr 1.14fr; gap: 24px; }
.contact-card, .map-card { overflow: hidden; border: 1px solid var(--line); border-radius: 16px; background: #fff; box-shadow: 0 5px 20px rgba(16,24,40,.04); }
.contact-card { padding: 32px; }
.contact-card h2 { margin-bottom: 3px; }
.contact-role { color: var(--accent); font-weight: 700; }
.contact-list { margin: 28px 0; }
.contact-list > div { display: grid; grid-template-columns: 85px 1fr; gap: 12px; padding: 15px 0; border-top: 1px solid var(--line); }
.contact-list dt { color: var(--muted); font-size: .78rem; font-weight: 800; text-transform: uppercase; letter-spacing: .06em; }
.contact-list dd { margin: 0; color: var(--ink-soft); }
.contact-actions { display: flex; flex-wrap: wrap; gap: 9px; }
.contact-actions .button-secondary { border-color: var(--line); }
.map-card iframe { width: 100%; height: 100%; min-height: 480px; display: block; border: 0; }

/* Projects (legacy content, modernized) */
main.container { width: min(calc(100% - 40px), var(--max-width)); margin: 0 auto; padding: 0 0 78px; }
main.container > .page-hero { width: 100vw; margin-left: calc(50% - 50vw); }
.publications-landing { padding: 42px 0 16px; text-align: left; }
.publications-landing h1 { margin-bottom: 0; font-size: 1.75rem; }
.card-grid { display: grid; grid-template-columns: repeat(2, minmax(0, 1fr)); gap: 16px; }
.pub-card, .card { padding: 23px; border: 1px solid var(--line); border-radius: 14px; background: #fff; box-shadow: 0 4px 14px rgba(16,24,40,.04); }
.pub-card h3, .pub-card h4 { margin-bottom: 11px; font-size: 1.02rem; }
.pub-card p { margin: 6px 0; color: var(--ink-soft); font-size: .9rem; }

/* Activities */
.activity-section { width: 100%; max-width: none; margin: 0; padding: 0 0 78px; }
.activity-section > .page-hero { margin-bottom: 54px; }
.activity-block { width: min(calc(100% - 40px), 1100px); margin: 0 auto 58px; }
.activity-block h2 { color: var(--ink); font-size: 1.7rem; }
.activity-block h3 { margin: 30px 0 12px; font-size: 1.08rem; }
.activity-block p { color: var(--ink-soft); }
.activity-gallery-section { margin-top: 30px; }
.activity-gallery { display: grid; grid-template-columns: repeat(auto-fit, minmax(245px, 1fr)); gap: 16px; align-items: stretch; }
.activity-gallery-four { grid-template-columns: repeat(4, minmax(0, 1fr)); }
.activity-gallery-single { grid-template-columns: minmax(0, 680px); }
.activity-gallery figure { margin: 0; overflow: hidden; border: 1px solid var(--line); border-radius: 14px; background: #fff; box-shadow: 0 5px 18px rgba(16,24,40,.07); }
.activity-gallery img { width: 100%; aspect-ratio: 4 / 3; display: block; object-fit: cover; object-position: center; background: #eef0f3; cursor: zoom-in; transition: transform .2s ease; }
.activity-gallery img:hover, .activity-gallery img:focus { transform: scale(1.025); }
.activity-gallery figcaption { padding: 10px 12px; border-top: 1px solid var(--line); color: var(--ink-soft); font-size: .82rem; }
.gallery-note { margin: -4px 0 14px; color: var(--muted); font-size: .84rem; }

/* Image lightbox */
body.lightbox-open { overflow: hidden; }
.zoomable-image, img[data-lightbox] { cursor: zoom-in; }
.image-lightbox { position: fixed; inset: 0; z-index: 5000; display: none; place-items: center; padding: 24px; background: rgba(7,12,20,.92); }
.image-lightbox.is-open { display: grid; }
.image-lightbox figure { width: min(96vw, 1500px); max-height: 94vh; margin: 0; display: grid; place-items: center; gap: 10px; }
.image-lightbox img { max-width: 100%; max-height: 86vh; width: auto; height: auto; display: block; object-fit: contain; background: #fff; box-shadow: 0 16px 60px rgba(0,0,0,.35); }
.image-lightbox figcaption { max-width: 900px; color: #e5e7eb; text-align: center; font-size: .9rem; }
.image-lightbox-close { position: fixed; top: 16px; right: 18px; width: 46px; height: 46px; border: 1px solid rgba(255,255,255,.28); border-radius: 50%; background: rgba(17,24,39,.9); color: #fff; cursor: pointer; font-size: 1.8rem; line-height: 1; }
.image-lightbox-close:hover, .image-lightbox-close:focus { background: #fff; color: #111827; outline: none; }

/* Selected publications by research area */
.selected-publications { padding-bottom: 34px; }
.selected-publications-intro { max-width: 850px; margin-bottom: 28px; color: var(--ink-soft); }
.research-publication-groups { display: grid; grid-template-columns: repeat(2, minmax(0, 1fr)); gap: 18px; }
.research-publication-group { padding: 24px; border: 1px solid var(--line); border-radius: 14px; background: #fff; box-shadow: 0 4px 14px rgba(16,24,40,.04); }
.research-publication-group h2 { margin-bottom: 15px; font-size: 1.15rem; }
.research-publication-group ul { margin: 0; padding: 0; list-style: none; display: grid; gap: 15px; }
.research-publication-group li { padding-top: 15px; border-top: 1px solid var(--line); }
.research-publication-group li:first-child { padding-top: 0; border-top: 0; }
.research-publication-group strong { display: block; margin-bottom: 4px; color: var(--ink); font-size: .9rem; line-height: 1.45; }
.research-publication-group span { color: var(--muted); font-size: .8rem; line-height: 1.45; }
.research-publication-group a { display: inline-block; margin-top: 5px; font-size: .78rem; font-weight: 750; text-decoration: none; }

/* Footer */
.site-footer { margin-top: 0; color: #d1d5db; background: #0f1720; border-top: 4px solid var(--accent); }
.footer-inner { width: min(calc(100% - 40px), var(--max-width)); margin: auto; padding: 38px 0 30px; display: flex; justify-content: space-between; align-items: center; gap: 34px; }
.footer-profile { display: flex; align-items: center; gap: 16px; }
.footer-profile img { width: 68px; height: 76px; border-radius: 8px; object-fit: cover; object-position: top; background: #fff; }
.footer-profile strong, .footer-profile span { display: block; }
.footer-profile strong { color: #fff; }
.footer-profile span { font-size: .82rem; }
.footer-profile a { color: #f0b8b8; font-size: .82rem; text-decoration: none; }
.footer-links { display: flex; flex-wrap: wrap; justify-content: flex-end; gap: 8px 18px; }
.footer-links a { color: #d1d5db; font-size: .82rem; font-weight: 650; text-decoration: none; }
.footer-links a:hover { color: #fff; }
.footer-bottom { padding: 15px 20px; border-top: 1px solid #29313c; color: #8f9aaa; text-align: center; font-size: .76rem; }
.back-to-top { position: fixed; right: 20px; bottom: 20px; z-index: 900; width: 44px; height: 44px; border: 1px solid rgba(255,255,255,.12); border-radius: 50%; background: #111827; color: #fff; box-shadow: var(--shadow); cursor: pointer; opacity: 0; transform: translateY(10px); pointer-events: none; transition: opacity .2s, transform .2s; }
.back-to-top.is-visible { opacity: 1; transform: translateY(0); pointer-events: auto; }

@media (max-width: 1120px) {
  .nav-toggle { display: block; }
  .site-nav { position: absolute; inset: 72px 0 auto 0; margin: 0; background: #111827; border-top: 1px solid #2a3443; box-shadow: 0 18px 30px rgba(0,0,0,.25); }
  .main-menu { display: none; width: min(calc(100% - 32px), 900px); margin: 0 auto; padding: 12px 0 18px; flex-direction: column; align-items: stretch; gap: 2px; }
  .main-menu.open { display: flex; }
  .main-menu a { padding: 11px 12px; font-size: .92rem; }
  .main-menu a[aria-current="page"] { box-shadow: inset 3px 0 var(--accent); }
}

@media (max-width: 900px) {
  .section { padding: 62px 0; }
  .hero-inner { min-height: auto; grid-template-columns: 1fr; padding: 68px 0; gap: 46px; }
  .hero-portrait-wrap { justify-content: flex-start; }
  .hero-portrait-card { max-width: 280px; }
  .split-intro { grid-template-columns: 1fr; gap: 24px; }
  .research-card-grid, .profile-grid, .publication-feature-grid { grid-template-columns: repeat(2, 1fr); }
  .profile-grid .profile-card:last-child { grid-column: 1 / -1; }
  .research-detail { grid-template-columns: 1fr; gap: 25px; }
  .research-detail:nth-child(even) .research-detail-copy { order: initial; }
  .research-detail-copy { position: static; }
  .team-grid { grid-template-columns: 1fr; }
  .publication-toolbar { grid-template-columns: 1fr; gap: 18px; }
  .course-grid { grid-template-columns: repeat(2, 1fr); }
  .contact-grid { grid-template-columns: 1fr; }
  .map-card iframe { min-height: 360px; }
  .card-grid { grid-template-columns: 1fr; }
  .activity-gallery-four { grid-template-columns: repeat(2, minmax(0, 1fr)); }
  .research-publication-groups { grid-template-columns: 1fr; }
}

@media (max-width: 650px) {
  .container, .hero-inner, .nav-container, .footer-inner { width: min(calc(100% - 28px), var(--max-width)); }
  .nav-container { min-height: 66px; }
  .site-nav { inset: 66px 0 auto 0; }
  .brand-affiliation { font-size: .66rem; }
  .section { padding: 50px 0; }
  .page-hero { padding: 48px 0; }
  .hero-inner { padding: 54px 0 58px; }
  .hero-summary { font-size: 1rem; }
  .hero-actions { display: grid; grid-template-columns: 1fr 1fr; }
  .hero-actions .button:first-child { grid-column: 1 / -1; }
  .profile-links { gap: 8px 14px; }
  .section-heading { align-items: flex-start; flex-direction: column; gap: 10px; }
  .research-card-grid, .profile-grid, .publication-feature-grid, .course-grid { grid-template-columns: 1fr; }
  .profile-grid .profile-card:last-child { grid-column: auto; }
  .group-callout { padding: 28px 24px; align-items: flex-start; flex-direction: column; }
  .research-gallery-two, .research-gallery-three { grid-template-columns: 1fr; }
  .research-gallery img, .research-gallery-three img { min-height: 0; max-height: 72vh; }
  .research-detail-list { gap: 58px; }
  .member-card { grid-template-columns: 92px minmax(0,1fr); gap: 14px; padding: 15px; }
  .member-card > img { width: 92px; height: 110px; }
  .member-card p { font-size: .79rem; }
  .section-jump { justify-content: flex-start; overflow-x: auto; flex-wrap: nowrap; padding-bottom: 6px; }
  .section-jump a { flex: 0 0 auto; }
  .publication-entry { grid-template-columns: 32px minmax(0,1fr); gap: 10px; }
  .publication-index { width: 30px; height: 30px; }
  .toggle-btns { display: grid; grid-template-columns: 1fr 1fr; }
  .toggle-btns button { font-size: .83rem; }
  .facility-card { grid-template-columns: 1fr; gap: 14px; }
  .contact-card { padding: 24px 20px; }
  .contact-list > div { grid-template-columns: 1fr; gap: 3px; }
  .footer-inner { align-items: flex-start; flex-direction: column; }
  .footer-links { justify-content: flex-start; }
  .activity-block { width: min(calc(100% - 28px), 1100px); }
  .activity-gallery, .activity-gallery-four, .activity-gallery-single { grid-template-columns: 1fr; }
  .activity-gallery img { aspect-ratio: 4 / 3; }
  .image-lightbox { padding: 12px; }
}

@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }
  *, *::before, *::after { animation-duration: .01ms !important; animation-iteration-count: 1 !important; transition-duration: .01ms !important; }
}