/* ==========================================================================
   Shyang-En Weng — personal site
   One stylesheet, organised as: tokens · base · layout · components · pages
   ========================================================================== */

/* ---------- Font (self-hosted Geist, variable 300-700, latin subset; SIL OFL) ---------- */
@font-face {
    font-family: 'Geist';
    font-style: normal;
    font-weight: 300 700;
    font-display: swap;
    src: url('fonts/geist-latin.woff2') format('woff2');
    unicode-range: U+0000-00FF, U+0131, U+0152-0153, U+02BB-02BC, U+02C6, U+02DA, U+02DC, U+0304, U+0308, U+0329, U+2000-206F, U+20AC, U+2122, U+2191, U+2193, U+2212, U+2215, U+FEFF, U+FFFD;
}

/* ---------- Tokens ---------- */
:root {
    color-scheme: dark;
    --bg: #121212;
    --bg-rgb: 18, 18, 18;
    --surface: #1a1a1a;
    --surface-raised: #222;
    --paper: #fff;
    --line: rgba(255, 255, 255, .08);
    --line-strong: rgba(255, 255, 255, .16);
    --text: #f4f4f5;
    --cream: #f4f4f5;             /* headings (alias kept for readability of rules below) */
    --muted: #a1a1aa;
    --faint: #8b8b93;
    --tan: #a1a1aa;               /* quiet labels, dates, tags */
    --tan-line: rgba(255, 255, 255, .16);
    --accent: #fb923c;
    --accent-strong: #f97316;
    --accent-soft: rgba(251, 146, 60, .11);
    --accent-line: rgba(251, 146, 60, .3);
    --ink: #121212;               /* text on accent backgrounds */
    --font: 'Geist', sans-serif;   /* Chinese falls back to the browser's default sans-serif, as on the original site */
    --nav-h: 4.5rem;
    --gutter: clamp(1.25rem, 4vw, 2.25rem);
    --radius: 8px;
    --radius-lg: 14px;
    --ease: 240ms cubic-bezier(.22, 1, .36, 1);
}

/* ---------- Base ---------- */
*, *::before, *::after { box-sizing: border-box; }
* { margin: 0; padding: 0; }
html { scroll-behavior: smooth; scroll-padding-top: calc(var(--nav-h) + 1rem); -webkit-text-size-adjust: 100%; }
body { background: var(--bg); color: var(--text); font: 400 16px/1.7 var(--font); overflow-x: hidden; }
img { display: block; max-width: 100%; height: auto; }
ul, ol { list-style: none; }
a { color: inherit; text-decoration: none; transition: color var(--ease), background-color var(--ease), border-color var(--ease), opacity var(--ease); }
h1, h2, h3, h4 { line-height: 1.15; }
h1, h2 { color: var(--text); font-weight: 600; letter-spacing: -.035em; }
h3, h4 { font-weight: 600; letter-spacing: -.01em; }
p { max-width: 68ch; }
strong { color: var(--text); font-weight: 700; }
button { font: inherit; color: inherit; }
:focus-visible { outline: 2px solid var(--accent); outline-offset: 3px; }
[hidden] { display: none !important; }

.container { margin: 0 auto; max-width: 1120px; padding: 0 var(--gutter); }
.skip-link { background: var(--accent); color: var(--ink); font-weight: 700; left: 1rem; padding: .6rem 1rem; position: fixed; top: -4rem; z-index: 100; }
.skip-link:focus { top: 1rem; }
.eyebrow { color: var(--tan); font-size: .72rem; font-weight: 700; letter-spacing: .12em; line-height: 1.4; text-transform: uppercase; }
.muted { color: var(--muted); }

/* Scroll reveal: only hide content when JS is running */
.js .fade-in { opacity: 0; transform: translateY(14px); transition: opacity 600ms var(--ease), transform 600ms var(--ease); }
.js .fade-in.visible { opacity: 1; transform: none; }

/* ---------- Buttons, chips, badges ---------- */
.btn { align-items: center; background: var(--accent); border: 1px solid var(--accent); border-radius: var(--radius); color: var(--ink); cursor: pointer; display: inline-flex; font-size: .88rem; font-weight: 600; gap: .5rem; letter-spacing: .01em; padding: .7rem 1.25rem; }
.btn:hover { background: var(--accent-strong); border-color: var(--accent-strong); }
.btn-outline { background: transparent; border-color: var(--tan-line); color: var(--cream); }
.btn-outline:hover { background: rgba(255, 255, 255, .06); border-color: var(--tan); }
.btn-row { display: flex; flex-wrap: wrap; gap: .7rem; }
.text-link { color: var(--muted); font-size: .8rem; font-weight: 700; }
.text-link:hover { color: var(--accent); }
.text-link::after { color: var(--accent); content: ' ↗'; }
.text-link.internal::after { content: ' →'; }

.chips { display: flex; flex-wrap: wrap; gap: .4rem; }
.chip { border: 1px solid var(--tan-line); border-radius: 999px; color: var(--tan); font-size: .76rem; font-weight: 600; letter-spacing: .01em; padding: .18rem .6rem; }
.chip.is-neutral { border-color: var(--line-strong); color: var(--muted); }
.badge { background: var(--accent); border-radius: 999px; color: var(--ink); font-size: .74rem; font-weight: 700; letter-spacing: .01em; padding: .18rem .6rem; }

/* ---------- Navigation ---------- */
.site-nav { background: rgba(var(--bg-rgb), .9); backdrop-filter: blur(16px); border-bottom: 1px solid var(--line); height: var(--nav-h); left: 0; position: fixed; right: 0; top: 0; transition: background-color var(--ease), box-shadow var(--ease); z-index: 50; }
.site-nav.scrolled { background: rgba(var(--bg-rgb), .97); box-shadow: 0 8px 24px -16px rgba(0, 0, 0, .6); }
.site-nav .container { align-items: center; display: flex; gap: 1.5rem; height: 100%; justify-content: space-between; }
.logo a { align-items: center; display: inline-flex; font-size: .85rem; font-weight: 600; gap: .6rem; letter-spacing: .08em; text-transform: uppercase; white-space: nowrap; }
.logo a::before { background: var(--accent); border-radius: 50%; content: ''; height: .45rem; width: .45rem; }
.nav-links { align-items: center; display: flex; gap: 1.4rem; }
.nav-links a { color: var(--muted); font-size: .8rem; font-weight: 600; padding: .3rem 0; }
.nav-links a:hover, .nav-links a[aria-current] { color: var(--cream); text-decoration: underline; text-decoration-color: var(--accent); text-decoration-thickness: 1px; text-underline-offset: 8px; }
.nav-links .btn { color: var(--cream); margin-left: .3rem; padding: .35rem .85rem; text-decoration: none; }
.nav-links .btn:hover { color: var(--text); }
.nav-toggle { background: none; border: 1px solid var(--line-strong); cursor: pointer; display: none; height: 2.5rem; padding: 0; position: relative; width: 2.5rem; }
.nav-toggle span, .nav-toggle span::before, .nav-toggle span::after { background: var(--text); content: ''; display: block; height: 2px; left: 50%; position: absolute; top: 50%; transform: translate(-50%, -50%); transition: transform var(--ease), opacity var(--ease); width: 1.1rem; }
.nav-toggle span::before { transform: translate(-50%, -6px); }
.nav-toggle span::after { transform: translate(-50%, 4px); }
.nav-toggle[aria-expanded="true"] span { background: transparent; }
.nav-toggle[aria-expanded="true"] span::before { transform: translate(-50%, -50%) rotate(45deg); }
.nav-toggle[aria-expanded="true"] span::after { transform: translate(-50%, -50%) rotate(-45deg); }

/* ---------- Sections ---------- */
main { display: block; }
.section { padding: clamp(5rem, 10vw, 8.5rem) 0 0; }
.section-title { font-size: clamp(1.9rem, 3.2vw, 2.6rem); line-height: 1.1; margin-bottom: 2.6rem; }
.section-head { align-items: flex-end; display: flex; flex-wrap: wrap; gap: 1rem 2rem; justify-content: space-between; margin-bottom: 2.2rem; }
.section-head .section-title { margin-bottom: 0; }
.section-actions { align-items: center; display: flex; flex-wrap: wrap; gap: .8rem 1.3rem; }
.subsection-head { margin: 4rem 0 1rem; }
.subsection-head h3 { font-size: 1.5rem; margin-top: .3rem; }

/* ---------- Home: hero ---------- */
.hero { align-items: center; background: var(--bg); display: flex; isolation: isolate; min-height: min(100svh, 860px); padding: calc(var(--nav-h) + 4rem) 0 5rem; position: relative; }
.hero::before { background: url('images/IMG_4067-800.webp') center / cover; content: ''; inset: 0; position: absolute; z-index: -2; }
.hero::after { background: linear-gradient(90deg, rgba(var(--bg-rgb), .9) 0%, rgba(var(--bg-rgb), .62) 48%, rgba(var(--bg-rgb), .15) 100%), linear-gradient(to bottom, rgba(var(--bg-rgb), 0) 55%, var(--bg) 100%); content: ''; inset: 0; position: absolute; z-index: -1; }
.hero-content { align-items: center; display: flex; gap: 4rem; justify-content: space-between; width: 100%; }
.hero-text { flex: 1 1 auto; max-width: 720px; }
.hero h1 { font-size: clamp(2.8rem, 7vw, 5rem); line-height: 1; margin: 1.1rem 0 0; white-space: nowrap; }
.hero-lead { color: #e4e4e7; font-size: 1.12rem; line-height: 1.7; margin: 1.6rem 0 0; max-width: 33em; }
.hero .btn-row { margin-top: 2.2rem; }
.hero-note { color: var(--tan); font-size: .85rem; margin-top: 2.2rem; }
.hero-photo { flex: none; }
.profile-pic { border: 1px solid var(--line-strong); border-radius: 50%; height: 260px; object-fit: cover; width: 260px; }

@media (min-width: 900px) {
    .hero::before { background-image: url('images/IMG_4067.webp'); }
}

/* ---------- Home: about ---------- */
.about-grid { align-items: start; display: grid; gap: clamp(2rem, 6vw, 6rem); grid-template-columns: minmax(0, 1.2fr) minmax(280px, .8fr); }
.about-copy { color: var(--muted); font-size: 1.08rem; line-height: 1.85; max-width: 55ch; }
.focus-list { border-top: 1px solid var(--line); }
.focus-list li { border-bottom: 1px solid var(--line); display: grid; gap: .1rem .8rem; grid-template-columns: 2rem 1fr; padding: .9rem 0; }
.focus-list span { color: var(--tan); font-size: .7rem; font-weight: 700; grid-row: span 2; padding-top: .3rem; }
.focus-list strong { font-size: .95rem; }
.focus-list p { color: var(--muted); font-size: .85rem; }

/* ---------- Timeline (education, experience, awards) ---------- */
.timeline { border-top: 1px solid var(--line); }
.timeline-item { border-bottom: 1px solid var(--line); display: grid; gap: 3rem; grid-template-columns: 145px minmax(0, 1fr); padding: 1.7rem 0; }
.timeline-date { color: var(--tan); font-size: .85rem; font-variant-numeric: tabular-nums; font-weight: 600; padding-top: .15rem; }
.timeline-body > h3 { font-size: 1.05rem; margin-bottom: .25rem; }
.timeline-sub { color: var(--muted); display: block; font-size: .9rem; margin-bottom: .6rem; }
.timeline-body p, .timeline-body li { color: var(--muted); font-size: .92rem; }
.timeline-body p + p { margin-top: .5rem; }
.timeline-body .aside { font-style: italic; margin-bottom: .5rem; }
.timeline-body ul { list-style: disc; margin: .6rem 0 0 1.2rem; }
.coursework { margin-top: .8rem; }
.coursework summary { color: var(--tan); cursor: pointer; font-size: .8rem; font-weight: 700; width: fit-content; }
.coursework summary:hover { color: var(--cream); }
.coursework ul { list-style: none; margin: .6rem 0 0; }
.coursework li { padding: .15rem 0; }
.coursework li strong { color: var(--text); font-weight: 600; }

/* ---------- Project cards ---------- */
.card-grid { display: grid; gap: 1.5rem; grid-template-columns: repeat(2, minmax(0, 1fr)); }
.card-grid.is-3 { grid-template-columns: repeat(3, minmax(0, 1fr)); }
.project-card { background: var(--surface); border: 1px solid var(--line); border-radius: var(--radius-lg); display: flex; flex-direction: column; overflow: hidden; position: relative; transition: border-color var(--ease), transform var(--ease), box-shadow var(--ease); }
.project-card:hover { border-color: var(--accent-line); box-shadow: 0 14px 30px -20px rgba(0, 0, 0, .7); transform: translateY(-3px); }
.card-thumb { aspect-ratio: 16 / 10; background: var(--paper); border-bottom: 1px solid var(--line); display: block; overflow: hidden; position: relative; }
.card-thumb img { height: 100%; object-fit: contain; padding: .6rem; width: 100%; }
.card-thumb.is-cover img { object-fit: cover; padding: 0; }
.card-thumb .badge { left: .7rem; position: absolute; top: .7rem; }
.card-body { display: flex; flex: 1; flex-direction: column; gap: .7rem; padding: 1.2rem 1.3rem 1.4rem; }
.card-meta { color: var(--tan); font-size: .8rem; font-variant-numeric: tabular-nums; font-weight: 600; }
.card-body h3 { color: var(--cream); font-size: 1.12rem; line-height: 1.3; }
.card-body h3 a::after { content: ''; inset: 0; position: absolute; }   /* whole card is clickable */
.card-body p { color: var(--muted); font-size: .92rem; }
.card-more { color: var(--accent); font-size: .78rem; font-weight: 700; margin-top: auto; padding-top: .4rem; }
.project-card:hover .card-more { color: var(--accent-strong); }

@media (min-width: 1001px) {
    .card-grid.is-3 > .project-card:last-child:nth-child(3n + 1) { display: grid; grid-column: 1 / -1; grid-template-columns: minmax(0, 1fr) minmax(0, 1.6fr); }
    .card-grid.is-3 > .project-card:last-child:nth-child(3n + 1) .card-thumb { aspect-ratio: auto; border-bottom: 0; border-right: 1px solid var(--line); min-height: 220px; }
    .card-grid.is-3 > .project-card:last-child:nth-child(3n + 1) .card-body { justify-content: center; padding: 1.6rem 2rem; }
}

/* ---------- Publications ---------- */
.pub { border-top: 1px solid var(--line); padding: 1.3rem 0 1.4rem; }
.pub-title { font-size: 1rem; font-weight: 600; line-height: 1.5; }
.pub-authors { color: var(--muted); font-size: .86rem; margin-top: .4rem; max-width: none; }
.pub-venue { color: var(--faint); font-size: .8rem; margin-top: .25rem; max-width: none; }
.pub-foot { align-items: center; display: flex; flex-wrap: wrap; gap: .5rem .6rem; margin-top: .8rem; }
.pub-tags { align-items: center; display: flex; flex-wrap: wrap; gap: .4rem; margin-bottom: .6rem; }
.pub-link { border: 1px solid var(--tan-line); border-radius: 999px; color: var(--cream); font-size: .74rem; font-weight: 600; padding: .25rem .6rem; }
.pub-link:hover { background: rgba(255, 255, 255, .06); border-color: var(--tan); }
.pub-project { color: var(--accent); font-size: .78rem; font-weight: 700; }
.pub-project:hover { color: var(--accent-strong); }
.pub-grid { display: grid; gap: 0 2.5rem; grid-template-columns: repeat(2, minmax(0, 1fr)); }
.year-group { border-top: 1px solid var(--line); display: grid; gap: 1rem 3rem; grid-template-columns: 110px minmax(0, 1fr); padding: 1.4rem 0 .4rem; }
.year-group > h3 { align-self: start; color: var(--text); font-size: 1.5rem; font-variant-numeric: tabular-nums; font-weight: 600; letter-spacing: -.02em; line-height: 1.2; position: sticky; top: calc(var(--nav-h) + 4.5rem); }
.year-group .pub:first-child { border-top: 0; padding-top: 0; }

.service { border-top: 1px solid var(--line); margin-top: 3rem; padding-top: 1.6rem; }
.service h3 { align-items: baseline; display: flex; font-size: 1rem; gap: .8rem; margin-bottom: .9rem; }

/* Compact variants used on the home page highlights */
.card-grid.is-compact { gap: 1rem; }
.is-compact .card-thumb { aspect-ratio: 2 / 1; }
.is-compact .card-thumb img { padding: .4rem; }
.is-compact .card-thumb.is-cover img { padding: 0; }
.is-compact .card-body { gap: .35rem; padding: .85rem 1rem 1rem; }
.is-compact .card-meta { font-size: .68rem; }
.is-compact .card-body h3 { font-size: .98rem; }
.is-compact .card-body p { -webkit-box-orient: vertical; display: -webkit-box; -webkit-line-clamp: 2; line-clamp: 2; font-size: .84rem; overflow: hidden; }
.is-compact .card-more { font-size: .72rem; padding-top: .2rem; }
.pub-grid.is-compact { gap: 0 2rem; }
.is-compact .pub { padding: .85rem 0 .95rem; }
.is-compact .pub-title { font-size: .9rem; line-height: 1.45; }
.is-compact .pub-authors { font-size: .78rem; margin-top: .25rem; }
.is-compact .pub-venue { font-size: .74rem; margin-top: .15rem; }
.is-compact .pub-foot { gap: .4rem .5rem; margin-top: .5rem; }
.is-compact .pub-link { font-size: .7rem; padding: .15rem .5rem; }
.is-compact .pub-project { display: none; }   /* shown on the full research page */
.subsection-head.is-tight { margin-top: 2.5rem; }

/* ---------- Contact & footer ---------- */
.contact-grid { background: var(--line); border: 1px solid var(--line); border-radius: var(--radius-lg); display: grid; overflow: hidden; gap: 1px; grid-template-columns: repeat(4, 1fr); }
.contact-card:first-child { grid-column: span 2; }   /* email is the longest value; seven cards then fill two rows */
.contact-card { background: var(--surface); padding: 1.25rem 1.4rem; }
.contact-card:hover { background: var(--surface-raised); }
.contact-icon { height: 24px; margin-bottom: 2.2rem; opacity: .8; width: 24px; }
.contact-card h3 { color: var(--cream); font-size: .95rem; font-weight: 600; }
.contact-card p { color: var(--muted); font-size: .8rem; margin-top: .3rem; overflow-wrap: anywhere; }
.contact-actions { display: flex; flex-wrap: wrap; gap: 1rem; justify-content: center; margin-top: 2.5rem; }

.site-footer { border-top: 1px solid var(--line); margin-top: clamp(4rem, 8vw, 7rem); padding: 2.5rem 0; }
.site-footer .container { align-items: center; display: flex; flex-wrap: wrap; gap: 1.5rem; justify-content: space-between; }
.social-links { display: flex; gap: .9rem; }
.social-icon { height: 18px; opacity: .55; transition: opacity var(--ease), transform var(--ease); width: 18px; }
.social-links a:hover .social-icon { opacity: 1; transform: translateY(-2px); }
.social-icon.is-color, .contact-icon.is-color { opacity: 1; }
.footer-text { color: var(--faint); font-size: .78rem; }

.back-to-top { background: var(--accent); border: 0; bottom: 1.5rem; color: var(--ink); cursor: pointer; display: grid; height: 40px; opacity: 0; place-items: center; pointer-events: none; position: fixed; right: 1.5rem; transform: translateY(10px); transition: opacity var(--ease), transform var(--ease), background-color var(--ease); width: 40px; z-index: 40; }
.back-to-top.visible { opacity: 1; pointer-events: auto; transform: none; }
.back-to-top:hover { background: var(--accent-strong); }

/* ---------- Inner pages: header ---------- */
.page-head { background: linear-gradient(180deg, var(--surface) 0%, var(--bg) 100%); border-bottom: 1px solid var(--line); padding: calc(var(--nav-h) + 3rem) 0 3rem; }
.page-head h1 { font-size: clamp(2.4rem, 5vw, 3.8rem); line-height: 1.06; margin: .7rem 0 0; max-width: 20ch; text-wrap: balance; }
.page-lead { color: var(--muted); font-size: 1.08rem; margin-top: 1.1rem; max-width: 60ch; }
.page-head .subtitle { color: var(--muted); font-size: 1.1rem; font-weight: 500; margin-top: .8rem; }
.page-head .chips { margin-top: 1.4rem; }
.page-head .btn-row { margin-top: 1.6rem; }
.breadcrumb { align-items: center; color: var(--faint); display: flex; flex-wrap: wrap; font-size: .8rem; font-weight: 600; gap: .5rem; margin-bottom: 1.6rem; }
.breadcrumb a:hover { color: var(--accent); }
.breadcrumb [aria-current] { color: var(--tan); }
.stat-row { border-top: 1px solid var(--line); display: flex; flex-wrap: wrap; gap: 1.5rem 3.5rem; margin-top: 2.5rem; padding-top: 1.5rem; }
.stat strong { color: var(--text); display: block; font-size: 2.4rem; font-variant-numeric: tabular-nums; font-weight: 600; letter-spacing: -.03em; line-height: 1; }
.stat span { color: var(--muted); font-size: .85rem; }

/* ---------- Research page ---------- */
.toolbar { background: rgba(var(--bg-rgb), .92); backdrop-filter: blur(14px); border-bottom: 1px solid var(--line); position: sticky; top: var(--nav-h); z-index: 30; }
.toolbar .container { align-items: center; display: flex; gap: 1.5rem; height: 3.4rem; }
.tabs { display: flex; gap: 1.8rem; }
.tabs a { border-bottom: 2px solid transparent; color: var(--muted); font-size: .92rem; font-weight: 600; padding: .85rem 0; }
.tabs a:hover { color: var(--cream); }
.tabs a[aria-current="true"] { border-color: var(--accent); color: var(--cream); }
.filters { display: flex; flex-wrap: wrap; gap: .5rem; margin-bottom: 1.6rem; }
.filter { background: transparent; border: 1px solid var(--tan-line); border-radius: 999px; color: var(--muted); cursor: pointer; font-size: .78rem; font-weight: 600; padding: .35rem .85rem; }
.filter:hover { border-color: var(--tan); color: var(--cream); }
.filter[aria-pressed="true"] { background: var(--cream); border-color: var(--cream); color: var(--ink); }
.callout { align-items: center; background: var(--surface); border: 1px solid var(--line); border-radius: var(--radius-lg); display: flex; flex-wrap: wrap; gap: .8rem 1.5rem; justify-content: space-between; margin-top: 2.2rem; padding: 1.1rem 1.3rem; }
.callout p { color: var(--text); font-size: .95rem; }
.callout .eyebrow { font-size: .72rem; margin-bottom: .2rem; }

/* ---------- Project page ---------- */
.project-layout { align-items: start; display: grid; gap: 4rem; grid-template-columns: minmax(0, 1fr) 280px; padding-top: 3.5rem; }
.prose > section { margin-bottom: 3rem; }
.prose h2 { font-size: 1.7rem; line-height: 1.15; margin-bottom: 1rem; }
.prose p, .prose li { color: var(--muted); }
.prose p + p { margin-top: .9rem; }
.prose ul { list-style: disc; margin: 1rem 0 0 1.3rem; }
.prose li + li { margin-top: .5rem; }
.prose p a, .prose li a { color: var(--cream); text-decoration: underline; text-decoration-color: var(--accent); text-underline-offset: 3px; }
.prose p a:hover, .prose li a:hover { color: var(--accent); }
.figure { margin-bottom: 1.4rem; }
.figure-frame { background: var(--paper); border: 0; border-radius: var(--radius-lg); cursor: zoom-in; display: block; padding: .8rem; width: 100%; }
.figure-frame img { margin: 0 auto; max-height: 560px; object-fit: contain; width: auto; }
.figure-frame:hover { box-shadow: 0 0 0 2px var(--accent); }
.figure figcaption { color: var(--faint); font-size: .8rem; margin-top: .5rem; }
.project-aside { align-self: start; position: sticky; top: calc(var(--nav-h) + 1.5rem); }
.aside-block { border-top: 1px solid var(--line); padding: 1.1rem 0 1.4rem; }
.aside-block h2 { color: var(--tan); font-family: var(--font); font-size: .72rem; font-weight: 700; letter-spacing: .12em; margin-bottom: .7rem; text-transform: uppercase; }
.facts dt { color: var(--tan); font-size: .8rem; font-weight: 600; margin-top: .8rem; }
.facts dt:first-child { margin-top: 0; }
.facts dd { color: var(--text); font-size: .9rem; }
.toc a { border-left: 2px solid var(--line); color: var(--muted); display: block; font-size: .85rem; padding: .3rem 0 .3rem .9rem; }
.toc a:hover { color: var(--text); }
.toc a[aria-current="true"] { border-color: var(--accent); color: var(--cream); }
.pager { border-top: 1px solid var(--line); display: grid; gap: 1.5rem; grid-template-columns: 1fr 1fr; margin-top: 4rem; padding-top: 2rem; }
.pager a { border: 1px solid var(--line); border-radius: var(--radius-lg); display: block; padding: 1.1rem 1.3rem; }
.pager a:hover { background: var(--surface); border-color: var(--accent-line); }
.pager small { color: var(--tan); display: block; font-size: .8rem; font-weight: 600; }
.pager span { display: block; font-weight: 600; margin-top: .2rem; }
.pager .next { grid-column: 2; text-align: right; }

/* ---------- Image lightbox ---------- */
.lightbox { background: transparent; border: 0; height: 100%; max-height: none; max-width: none; padding: 0; width: 100%; }
.lightbox::backdrop { background: rgba(10, 9, 8, .88); }
.lightbox-inner { align-items: center; cursor: zoom-out; display: flex; height: 100%; justify-content: center; padding: 1.5rem; width: 100%; }
.lightbox img { background: var(--paper); border-radius: var(--radius); max-height: 100%; max-width: 100%; object-fit: contain; padding: .8rem; }

/* ---------- Responsive ---------- */
@media (max-width: 1000px) {
    .card-grid.is-3 { grid-template-columns: repeat(2, minmax(0, 1fr)); }
    .project-layout { gap: 2.5rem; grid-template-columns: minmax(0, 1fr) 240px; }
}

@media (max-width: 860px) {
    :root { --nav-h: 4rem; }
    .site-nav .container { gap: 0; }
    .nav-toggle { display: block; margin-left: auto; }
    .nav-links { align-items: stretch; background: var(--bg); border-bottom: 1px solid var(--line); flex-direction: column; gap: 0; left: 0; padding: .5rem var(--gutter) 1.2rem; position: absolute; right: 0; top: var(--nav-h); }
    .js .nav-links { display: none; }
    .js .nav-links.is-open { display: flex; }
    .nav-links li { display: block; }
    .nav-links a { border-bottom: 1px solid var(--line); display: block; font-size: .95rem; padding: .85rem 0; }
    .nav-links .btn { border: 1px solid var(--tan-line); color: var(--cream); display: flex; justify-content: center; margin: 1rem 0 0; padding: .7rem; }
    html:not(.js) .site-nav { height: auto; }
    html:not(.js) .site-nav .container { gap: 1.5rem; }
    html:not(.js) .nav-toggle { display: none; }
    html:not(.js) .site-nav .container { flex-wrap: wrap; padding-bottom: .6rem; padding-top: .8rem; }
    html:not(.js) .nav-links { background: none; border: 0; flex-direction: row; flex-wrap: wrap; gap: .3rem 1rem; padding: 0; position: static; }
    html:not(.js) .nav-links a { border: 0; font-size: .8rem; padding: .2rem 0; }

    .hero { min-height: auto; padding: calc(var(--nav-h) + 2.5rem) 0 4rem; }
    .hero-content { align-items: flex-start; flex-direction: column-reverse; gap: 2rem; }
    .profile-pic { height: 112px; width: 112px; }
    .hero-photo::after { display: none; }
    .hero::after { background: linear-gradient(180deg, rgba(var(--bg-rgb), .55) 0%, rgba(var(--bg-rgb), .8) 60%, var(--bg) 100%); }
    .hero h1 { white-space: normal; }
    .about-grid { grid-template-columns: 1fr; }
    .timeline-item { gap: .4rem; grid-template-columns: 1fr; }
    .card-grid, .card-grid.is-3, .pub-grid { grid-template-columns: 1fr; }
    .contact-grid { grid-template-columns: repeat(2, 1fr); }
    .year-group { grid-template-columns: 1fr; }
    .year-group > h3 { position: static; }
    .project-layout { grid-template-columns: 1fr; }
    .project-aside { position: static; }
    .project-aside .toc-block { display: none; }
    .toolbar .container { overflow-x: auto; }
}

@media (max-width: 520px) {
    .stat-row { display: grid; gap: 1rem; grid-template-columns: repeat(3, 1fr); }
    .stat strong { font-size: 2.3rem; }
    .stat span { display: block; font-size: .74rem; line-height: 1.35; margin-top: .25rem; }
    /* contact: one column, icon beside the text, so long values (email) never break mid-word */
    .contact-grid { grid-template-columns: 1fr; }
    .contact-card:first-child { grid-column: auto; }
    .contact-card { align-items: center; column-gap: 1rem; display: grid; grid-template-columns: 24px 1fr; padding: 1rem 1.2rem; }
    .contact-icon { grid-row: span 2; margin-bottom: 0; }
    .contact-card p { margin-top: 0; }
    .pager { grid-template-columns: 1fr; }
    .pager .next { grid-column: 1; text-align: left; }
    .hero .btn-row .btn { flex: 1 1 100%; justify-content: center; }
    .hero-note { line-height: 1.8; max-width: 30ch; }
}

@media (prefers-reduced-motion: reduce) {
    html { scroll-behavior: auto; }
    *, *::before, *::after { transition-duration: .01ms !important; }
    .js .fade-in { opacity: 1; transform: none; }
}