/* ===== Design tokens ===== */
:root {
  --brand: #0a5bc4;
  --brand-strong: #084a9f;
  --brand-soft: #eaf2fd;
  --bg: #f7f8fa;
  --surface: #ffffff;
  --text: #0f172a;
  --text-2: #334155;
  --muted: #64748b;
  --line: #e4e7ec;
  --line-strong: #d0d5dd;
  --badge-bg: #f1f5f9;
  --accent-bg: #ecfdf3;
  --accent-text: #067647;
  --shadow: 0 1px 2px rgba(16, 24, 40, 0.04), 0 4px 16px rgba(16, 24, 40, 0.05);
  --radius: 14px;
  --maxw: 860px;
  color-scheme: light;
}
@media (prefers-color-scheme: dark) {
  :root:not([data-theme="light"]) {
    --brand: #7cb2ff;
    --brand-strong: #a3c9ff;
    --brand-soft: #13243d;
    --bg: #0b0f16;
    --surface: #121822;
    --text: #e6e9ef;
    --text-2: #c3cad6;
    --muted: #8d97a8;
    --line: #222b38;
    --line-strong: #2f3a4a;
    --badge-bg: #1a2230;
    --accent-bg: #0f2a1e;
    --accent-text: #6ce0a6;
    --shadow: 0 1px 2px rgba(0, 0, 0, 0.4), 0 4px 16px rgba(0, 0, 0, 0.25);
    color-scheme: dark;
  }
}
:root[data-theme="dark"] {
  --brand: #7cb2ff;
  --brand-strong: #a3c9ff;
  --brand-soft: #13243d;
  --bg: #0b0f16;
  --surface: #121822;
  --text: #e6e9ef;
  --text-2: #c3cad6;
  --muted: #8d97a8;
  --line: #222b38;
  --line-strong: #2f3a4a;
  --badge-bg: #1a2230;
  --accent-bg: #0f2a1e;
  --accent-text: #6ce0a6;
  --shadow: 0 1px 2px rgba(0, 0, 0, 0.4), 0 4px 16px rgba(0, 0, 0, 0.25);
  color-scheme: dark;
}

/* ===== Base ===== */
* { box-sizing: border-box; }
html { scroll-behavior: smooth; -webkit-text-size-adjust: 100%; }
body {
  margin: 0;
  font-family: Inter, system-ui, -apple-system, "Segoe UI", Roboto, Arial, sans-serif;
  font-size: 16px;
  line-height: 1.65;
  color: var(--text);
  background: var(--bg);
  -webkit-font-smoothing: antialiased;
}
a { color: var(--brand); text-decoration-thickness: 1px; text-underline-offset: 3px; }
a:hover { color: var(--brand-strong); }
:focus-visible { outline: 2px solid var(--brand); outline-offset: 2px; border-radius: 6px; }
p { margin: 0 0 12px; }
h1, h2, h3 { letter-spacing: -0.02em; line-height: 1.25; color: var(--text); }
.container { max-width: var(--maxw); margin: 0 auto; padding: 0 20px; }
.muted { color: var(--muted); }

.skip-link { position: absolute; left: -999px; top: 0; }
.skip-link:focus { left: 16px; top: 12px; padding: 8px 12px; background: var(--surface); border: 2px solid var(--brand); border-radius: 8px; z-index: 100; }

/* ===== Header ===== */
.site-header {
  position: sticky; top: 0; z-index: 50;
  background: color-mix(in srgb, var(--bg) 85%, transparent);
  backdrop-filter: saturate(180%) blur(10px);
  -webkit-backdrop-filter: saturate(180%) blur(10px);
  border-bottom: 1px solid var(--line);
}
.topbar { display: flex; align-items: center; gap: 16px; height: 60px; }
.brand { font-weight: 700; font-size: 1.02rem; letter-spacing: -0.01em; color: var(--text); text-decoration: none; margin-right: auto; }
.brand:hover { color: var(--text); }
.nav { display: flex; gap: 4px; list-style: none; margin: 0; padding: 0; }
.nav a {
  display: block; padding: 6px 12px; border-radius: 8px;
  font-weight: 500; font-size: .95rem; color: var(--text-2); text-decoration: none;
}
.nav a:hover { background: var(--badge-bg); color: var(--text); }
.nav a[aria-current="page"] { color: var(--brand); background: var(--brand-soft); }
.icon-btn {
  display: inline-grid; place-items: center; width: 36px; height: 36px;
  border: 1px solid var(--line); border-radius: 9px;
  background: var(--surface); color: var(--text-2); cursor: pointer;
}
.icon-btn:hover { border-color: var(--line-strong); color: var(--text); }

/* ===== Buttons & badges ===== */
.btn {
  display: inline-flex; align-items: center; gap: 6px;
  padding: 6px 12px; border-radius: 8px;
  font: inherit; font-size: .875rem; font-weight: 600; line-height: 1.4;
  text-decoration: none; cursor: pointer;
  border: 1px solid var(--line-strong); background: var(--surface); color: var(--text-2);
  transition: border-color .15s, color .15s, background .15s;
}
.btn:hover { border-color: var(--brand); color: var(--brand); }
.btn.primary { background: var(--brand); border-color: var(--brand); color: #fff; }
.btn.primary:hover { background: var(--brand-strong); border-color: var(--brand-strong); color: #fff; }
:root[data-theme="dark"] .btn.primary { color: #0b0f16; }
@media (prefers-color-scheme: dark) { :root:not([data-theme="light"]) .btn.primary { color: #0b0f16; } }
.btn svg { flex: none; }

.badge {
  display: inline-block; font-size: .8rem; font-weight: 500; line-height: 1.4;
  padding: 3px 10px; border-radius: 999px;
  background: var(--badge-bg); color: var(--text-2); border: 1px solid var(--line);
}
.badge.status { background: var(--brand-soft); color: var(--brand); border-color: transparent; }
.badge.new { background: var(--accent-bg); color: var(--accent-text); border-color: transparent; }

/* ===== Sections ===== */
main { padding: 40px 0 24px; }
.section { margin-top: 48px; }
.section-title {
  font-size: .8rem; font-weight: 600; text-transform: uppercase; letter-spacing: .08em;
  color: var(--muted); margin: 0 0 16px;
}
.card { background: var(--surface); border: 1px solid var(--line); border-radius: var(--radius); box-shadow: var(--shadow); }

/* ===== Home hero ===== */
.hero { display: grid; grid-template-columns: 168px 1fr; gap: 36px; align-items: start; }
.profile-photo { width: 168px; height: 168px; border-radius: 50%; object-fit: cover; border: 1px solid var(--line); box-shadow: var(--shadow); }
.hero h1 { font-size: clamp(2rem, 3vw + 1rem, 2.6rem); margin: 4px 0 4px; }
.hero .role { font-size: 1.05rem; color: var(--muted); margin: 0 0 18px; }
.hero .lead { font-size: 1.05rem; color: var(--text-2); }
.interests { display: flex; flex-wrap: wrap; gap: 8px; margin: 18px 0 22px; }
.hero-actions { display: flex; flex-wrap: wrap; gap: 8px; align-items: center; }
.email-slot { font-size: .9rem; color: var(--text-2); font-family: ui-monospace, SFMono-Regular, Menlo, monospace; }

.link-list { list-style: none; margin: 0; padding: 0; display: grid; grid-template-columns: repeat(auto-fill, minmax(180px, 1fr)); gap: 10px; }
.link-list a {
  display: flex; align-items: center; justify-content: space-between; gap: 8px;
  padding: 12px 16px; border: 1px solid var(--line); border-radius: 10px;
  background: var(--surface); color: var(--text); text-decoration: none; font-weight: 500;
}
.link-list a:hover { border-color: var(--brand); color: var(--brand); }

/* ===== Papers ===== */
.page-intro h1 { font-size: clamp(1.8rem, 2vw + 1rem, 2.2rem); margin: 0 0 8px; }
.page-intro p { color: var(--muted); max-width: 60ch; }
.papers { display: grid; gap: 16px; margin-top: 28px; }
.paper { padding: 22px 24px; }
.paper-title { font-size: 1.15rem; font-weight: 650; margin: 0 0 6px; }
.paper-title a { color: var(--text); text-decoration: none; }
.paper-title a:hover { color: var(--brand); }
.coauthors { color: var(--text-2); font-size: .95rem; margin: 0 0 10px; }
.coauthors a { color: inherit; text-decoration: underline; text-decoration-color: var(--line-strong); }
.coauthors a:hover { color: var(--brand); text-decoration-color: currentColor; }
.coauthors .aff { color: var(--muted); }
.badges { display: flex; flex-wrap: wrap; gap: 6px; margin: 0 0 10px; }
.presentations { font-size: .9rem; color: var(--muted); margin: 0 0 12px; }
.presentations strong { color: var(--text-2); font-weight: 600; }
.paper-actions { display: flex; flex-wrap: wrap; gap: 8px; align-items: center; }

.abstract-toggle .chev { transition: transform .2s; }
.abstract-toggle[aria-expanded="true"] { border-color: var(--brand); color: var(--brand); }
.abstract-toggle[aria-expanded="true"] .chev { transform: rotate(180deg); }
.abstract-body { margin-top: 14px; padding-top: 14px; border-top: 1px solid var(--line); color: var(--text-2); font-size: .95rem; }
.abstract-body p:last-child { margin-bottom: 0; }

/* ===== Footer ===== */
.site-footer { margin-top: 56px; border-top: 1px solid var(--line); }
.site-footer .container { display: flex; justify-content: space-between; flex-wrap: wrap; gap: 8px; padding-top: 20px; padding-bottom: 28px; font-size: .875rem; color: var(--muted); }

/* ===== Responsive ===== */
@media (max-width: 640px) {
  .container { padding: 0 16px; }
  main { padding-top: 28px; }
  .hero { grid-template-columns: 1fr; gap: 20px; }
  .profile-photo { width: 112px; height: 112px; }
  .paper { padding: 18px; }
  .nav a { padding: 6px 9px; }
}

/* Paper title row with year */
.paper-head { display: flex; align-items: baseline; justify-content: space-between; gap: 16px; margin: 0 0 6px; }
.paper-head .paper-title { margin: 0; }
.year { flex: none; font-size: .875rem; font-weight: 600; color: var(--muted); font-variant-numeric: tabular-nums; }

/* ===== Editorial layer: serif display type, flat paper list ===== */
:root { --serif: "Source Serif 4", "Source Serif Pro", Georgia, "Times New Roman", serif; }
:root:not([data-theme="dark"]) { --brand: #1d4f91; --brand-strong: #153b6e; --brand-soft: #eaf0f8; }
@media (prefers-color-scheme: dark) { :root:not([data-theme="light"]) { --brand: #8fb6ec; --brand-strong: #b4cff3; --brand-soft: #16243a; } }

.brand { font-family: var(--serif); font-size: 1.15rem; font-weight: 600; letter-spacing: 0; }
.hero h1, .page-intro h1 { font-family: var(--serif); font-weight: 600; letter-spacing: -0.01em; }
.hero .role { font-family: var(--serif); font-style: italic; font-size: 1.1rem; }
.paper-title { font-family: var(--serif); font-size: 1.3rem; font-weight: 600; letter-spacing: -0.005em; line-height: 1.3; }
.year { font-family: var(--serif); font-size: 1rem; font-weight: 400; }

.section-title {
  display: flex; align-items: center; gap: 12px;
  color: var(--text-2);
}
.section-title::after { content: ""; flex: 1; height: 1px; background: var(--line); }

/* Papers as a ruled list instead of boxed cards */
.papers { gap: 0; margin-top: 20px; border-top: 1px solid var(--line); }
.papers .paper.card, .section .paper.card {
  background: none; border: 0; border-radius: 0; box-shadow: none;
  padding: 26px 0; border-bottom: 1px solid var(--line);
}
.section .paper.card { border-top: 1px solid var(--line); }
.abstract-body { border-top: 0; padding-top: 0; max-width: 72ch; line-height: 1.7; }
.page-intro { padding-bottom: 4px; }
@media (max-width: 640px) { .papers .paper.card, .section .paper.card { padding: 22px 0; } }

/* Hero: photo sits beside name/title; bio runs full width below */
[hidden] { display: none !important; }
.hero { display: block; }
.hero-head { display: flex; align-items: center; gap: 28px; margin-bottom: 24px; }
.hero-head .profile-photo { width: 128px; height: 128px; flex: none; }
.hero-head h1 { margin: 0 0 4px; }
.hero-head .role { margin: 0; }
.hero-body .lead { max-width: 68ch; }
@media (max-width: 640px) {
  .hero-head { gap: 18px; }
  .hero-head .profile-photo { width: 88px; height: 88px; }
}