/* ============================================================
   style.css — Gabriele Tolomei · gtolomei.github.io
   Glass-light / glass-dark theme
   Theme auto-switches at 06:00 UTC (light) / 18:00 UTC (dark)
   ============================================================ */

/* ── Google Fonts ───────────────────────────────────────────── */
/* @import url('https://fonts.googleapis.com/css2?family=Inter:wght@400;500;600;700&display=swap'); */
@import url('https://fonts.googleapis.com/css2?family=Inter:wght@400;500;600;700&family=JetBrains+Mono:wght@400;500;600&display=swap');
/* ── CSS Custom Properties ──────────────────────────────────── */
:root {
  --font-sans: 'Inter', system-ui, -apple-system, 'Segoe UI', sans-serif;
  --font-mono: 'JetBrains Mono', 'Fira Code', 'Cascadia Code', monospace;

  --radius-xs:   0.25rem;
  --radius-sm:   0.5rem;
  --radius-md:   0.875rem;
  --radius-lg:   1.25rem;
  --radius-xl:   2rem;
  --radius-full: 9999px;

  --transition-fast: 150ms ease;
  --transition:      220ms ease;
  --transition-slow: 350ms ease;

  --nav-h:  3.75rem;
  --hero-pt: calc(var(--nav-h) + 3rem);

 /* Ocean teal palette */
  --grad-text: linear-gradient(135deg, #0f766e 0%, #0ea5e9 100%);
  --grad-ring: linear-gradient(135deg, #0f766e, #0ea5e9, #22c55e);

  /* Badge colours (type-agnostic, same in both themes) */
  --badge-conf-bg:     #d1fae5;
  --badge-conf-text:   #065f46;
  --badge-journal-bg:  #dbeafe;
  --badge-journal-text:#1e3a8a;
  --badge-workshop-bg: #fef3c7;
  --badge-workshop-text:#78350f;
  --badge-preprint-bg: #fee2e2;
  --badge-preprint-text:#7f1d1d;
  --badge-other-bg:    #f1f5f9;
  --badge-other-text:  #334155;

  /* Topic chip active colour — emerald */
  --chip-active-bg: #0ea5e9; /* blue-teal accent */
  --chip-active-text:  #fff;
}

/* ── Light Theme (default) ──────────────────────────────────── */
:root,
[data-theme="light"] {
  --bg:          #f1f5f9;
  --bg-alt:      #e8eef5;
  --bg-glass:    rgba(255, 255, 255, 0.72);
  --bg-card:     rgba(255, 255, 255, 0.85);
  --bg-chip:     rgba(0, 0, 0, 0.06);

  --border:        rgba(0, 0, 0, 0.08);
  --border-strong: rgba(0, 0, 0, 0.16);

  --text:          #0f172a;
  --text-muted:    #475569;
  --text-subtle:   #94a3b8;

  --accent:        #0f766e;   /* deep teal */
  --accent-hover:  #115e59;
  --accent-bg:     rgba(15, 118, 110, 0.10);

  --shadow-sm:  0 1px 4px rgba(0,0,0,0.07);
  --shadow:     0 4px 20px rgba(0,0,0,0.08);
  --shadow-lg:  0 12px 40px rgba(0,0,0,0.12);

  --blur: blur(18px);
}

/* ── Dark Theme ─────────────────────────────────────────────── */
[data-theme="dark"] {
  --bg:          #0b0e1a;
  --bg-alt:      #111527;
  --bg-glass:    rgba(12, 15, 28, 0.78);
  --bg-card:     rgba(18, 22, 38, 0.88);
  --bg-chip:     rgba(255, 255, 255, 0.07);

  --border:        rgba(255, 255, 255, 0.08);
  --border-strong: rgba(255, 255, 255, 0.16);

  --text:          #e2e8f0;
  --text-muted:    #94a3b8;
  --text-subtle:   #4b5878;

  --accent:        #22d3ee;
  --accent-hover:  #67e8f9;
  --accent-bg:     rgba(34, 211, 238, 0.14);

  --shadow-sm:  0 1px 4px rgba(0,0,0,0.4);
  --shadow:     0 4px 20px rgba(0,0,0,0.5);
  --shadow-lg:  0 12px 40px rgba(0,0,0,0.7);

  --blur: blur(18px);

  /* Slightly soften badges in dark mode */
  --badge-conf-bg:     rgba(16, 185, 129, 0.18);
  --badge-conf-text:   #6ee7b7;
  --badge-journal-bg:  rgba(59, 130, 246, 0.18);
  --badge-journal-text:#93c5fd;
  --badge-workshop-bg: rgba(245, 158, 11, 0.18);
  --badge-workshop-text:#fcd34d;
  --badge-preprint-bg: rgba(239, 68, 68, 0.18);
  --badge-preprint-text:#fca5a5;
  --badge-other-bg:    rgba(100, 116, 139, 0.18);
  --badge-other-text:  #94a3b8;
}

/* ── Reset & base ───────────────────────────────────────────── */
*, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }

html {
  scroll-behavior: smooth;
  scroll-padding-top: var(--nav-h);
  -webkit-text-size-adjust: 100%;
}

body {
  font-family: var(--font-sans);
  font-size: 1rem;       /* 16px base — accessible default */
  line-height: 1.7;
  color: var(--text);
  background: var(--bg);
  /* transition: background var(--transition-slow), color var(--transition-slow); */
  min-height: 100vh;
  position: relative;
}

/* ── Smooth Background Effect ───────────────────────────────── */
.bg-orbs {
  position: fixed;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  pointer-events: none;
  z-index: -1;
  overflow: hidden;
  background: var(--bg);
  transition: background var(--transition-slow);
}

.orb {
  position: absolute;
  border-radius: 50%;
  filter: blur(100px);
  opacity: 0.12;
  animation: orbFloat 25s infinite alternate ease-in-out;
}

.orb-1 {
  width: 50vw;
  height: 50vw;
  background: #0f766e; /* deep teal */
  top: -10%;
  left: -10%;
}

.orb-2 {
  width: 60vw;
  height: 60vw;
  background: #0ea5e9; /* blue */
  bottom: -15%;
  right: -10%;
  animation-delay: -7s;
}

.orb-3 {
  width: 40vw;
  height: 40vw;
  background: #22c55e; /* green */
  top: 30%;
  right: 20%;
  opacity: 0.08;
  animation-delay: -12s;
}

@keyframes orbFloat {
  0%   { transform: translate(0, 0) scale(1); }
  100% { transform: translate(60px, 40px) scale(1.15); }
}

a { color: var(--accent); text-decoration: none; }
a:hover { text-decoration: underline; color: var(--accent-hover); }

img { display: block; max-width: 100%; }

::selection {
  background: var(--accent-bg);
  color: var(--text);
}

/* Focus ring — accessibility */
:focus-visible {
  outline: 2px solid var(--accent);
  outline-offset: 3px;
  border-radius: var(--radius-sm);
}

/* ── Typography ─────────────────────────────────────────────── */
h1 { font-size: clamp(2rem, 5vw, 3.25rem); font-weight: 700; line-height: 1.15; }
h2 { font-size: clamp(1.5rem, 3vw, 2rem);  font-weight: 700; line-height: 1.25; }
h3 { font-size: 1.2rem;  font-weight: 600; line-height: 1.4; }
h4 { font-size: 1rem;    font-weight: 600; }

p { color: var(--text-muted); }

/* ── Mono font usage (badges, chips) ───────────────────────── */
.badge-pill,
.badge-year,
.type-pill,
.topic-chip,
.pub-chip {
  font-family: var(--font-mono);
  letter-spacing: 0.02em;
}

/* ── Layout helpers ─────────────────────────────────────────── */
.container {
  width: min(1100px, 100% - 2.5rem);
  margin-inline: auto;
}

.section {
  padding-block: 5rem;
}

.section-label {
  font-size: 1.5rem;   /* Increased font size */
  font-weight: 700;
  letter-spacing: 0.04em;
  text-transform: uppercase;
  color: var(--accent);
  margin-bottom: 2.75rem;
}

/* .section-title moved into .section-label */

/* ── Gradient text ──────────────────────────────────────────── */
.gradient-text {
  background: var(--grad-text);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}

/* ── Buttons ────────────────────────────────────────────────── */
.btn {
  display: inline-flex;
  align-items: center;
  gap: 0.4rem;
  padding: 0.65rem 1.4rem;
  border-radius: var(--radius-full);
  font-size: 0.9rem;
  font-weight: 500;
  cursor: pointer;
  border: none;
  transition: background var(--transition), color var(--transition),
              box-shadow var(--transition), transform var(--transition-fast);
  text-decoration: none !important;
}

.btn:hover { transform: translateY(-1px); }
.btn:active { transform: translateY(0); }

.btn-primary {
  background: var(--grad-text);
  color: #fff;
  box-shadow: 0 2px 12px rgba(14, 165, 233, 0.35);
}
.btn-primary:hover {
  box-shadow: 0 4px 20px rgba(14, 165, 233, 0.45);
  color: #fff;
}

.btn-ghost {
  background: var(--bg-chip);
  color: var(--text);
  border: 1px solid var(--border);
}
.btn-ghost:hover {
  background: var(--accent-bg);
  color: var(--accent);
  border-color: var(--accent);
}

/* ============================================================
   NAVIGATION
   ============================================================ */
#navbar {
  position: sticky;
  top: 0;
  z-index: 100;
  padding: 0.6rem 1rem;
  pointer-events: none;
}

.nav-pill {
  pointer-events: all;
  display: flex;
  align-items: center;
  gap: 0.25rem;
  width: fit-content;
  margin-inline: auto;
  padding: 0.4rem 0.6rem;
  background: var(--bg-glass);
  backdrop-filter: var(--blur);
  -webkit-backdrop-filter: var(--blur);
  border: 1px solid var(--border);
  border-radius: var(--radius-full);
  box-shadow: var(--shadow);
  overflow-x: auto;
  scrollbar-width: none;
  transition: background var(--transition-slow);
}
.nav-pill::-webkit-scrollbar { display: none; }

.nav-brand {
  font-weight: 700;
  font-size: 0.95rem;
  color: var(--accent);
  padding: 0.3rem 0.6rem;
  border-radius: var(--radius-full);
  flex-shrink: 0;
  text-decoration: none !important;
}

.nav-pill ul {
  display: flex;
  list-style: none;
  gap: 0.1rem;
  flex-shrink: 0;
}

.nav-pill a {
  display: block;
  padding: 0.3rem 0.75rem;
  font-size: 0.875rem;
  font-weight: 500;
  color: var(--text-muted);
  border-radius: var(--radius-full);
  white-space: nowrap;
  text-decoration: none !important;
  transition: background var(--transition-fast), color var(--transition-fast);
}
.nav-pill a:hover,
.nav-pill a.active {
  background: var(--accent-bg);
  color: var(--accent);
}

#theme-toggle {
  background: none;
  border: none;
  cursor: pointer;
  font-size: 1rem;
  padding: 0.3rem 0.5rem;
  border-radius: var(--radius-full);
  color: var(--text-muted);
  flex-shrink: 0;
  transition: background var(--transition-fast);
  line-height: 1;
}
#theme-toggle:hover { background: var(--bg-chip); }

/* Scholar shortcut in nav */
.nav-scholar {
  display: inline-flex;
  align-items: center;
  padding: 0.3rem 0.75rem;
  font-size: 0.875rem;
  font-weight: 500;
  color: var(--text-muted);
  border-radius: var(--radius-full);
  white-space: nowrap;
  flex-shrink: 0;
  transition: background var(--transition-fast), color var(--transition-fast);
}
.nav-scholar:hover {
  background: var(--accent-bg);
  color: var(--accent);
}

/* ============================================================
   HERO
   ============================================================ */
.hero {
  min-height: calc(100svh - var(--nav-h));
  display: flex;
  align-items: center;
  padding-block: 3rem 4rem;
}

.hero-content {
  width: min(1100px, 100% - 2.5rem);
  margin-inline: auto;
  display: grid;
  grid-template-columns: 1fr auto;
  gap: 3rem 4rem;
  align-items: center;
}

.hero-role {
  font-size: 0.9rem;
  font-weight: 500;
  color: var(--accent);
  margin-bottom: 0.5rem;
}

.hero-name {
  margin-bottom: 1.25rem;
  color: var(--text);
}

.hero-bio {
  font-size: 1.05rem;
  color: var(--text-muted);
  max-width: 60ch;
  margin-bottom: 2rem;
}

/* Stats row */
.hero-stats {
  display: flex;
  flex-wrap: wrap;
  gap: 1.5rem 2.5rem;
  margin-bottom: 2rem;
}

.stat { display: flex; flex-direction: column; gap: 0.1rem; }

.stat-value {
  font-size: 1.6rem;
  font-weight: 700;
  color: var(--text);
  line-height: 1.1;
}

.stat-label {
  font-size: 0.72rem;
  font-weight: 500;
  letter-spacing: 0.06em;
  text-transform: uppercase;
  color: var(--text-subtle);
}

/* CTA buttons */
.hero-links {
  display: flex;
  gap: 0.75rem;
  flex-wrap: wrap;
}

/* Profile photo */
.hero-photo {
  flex-shrink: 0;
}

.photo-ring {
  position: relative;
  width: 240px;
  height: 240px;
  border-radius: 50%;
  padding: 4px;
  background: var(--grad-ring);
}

.photo-ring img {
  width: 100%;
  height: 100%;
  border-radius: 50%;
  object-fit: cover;
  object-position: center top;
  display: block;
  background: var(--bg-alt);
}

/* ============================================================
   ABOUT
   ============================================================ */
.about-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 2rem;
}

.about-card {
  padding: 1.75rem;
  background: var(--bg-card);
  backdrop-filter: var(--blur);
  -webkit-backdrop-filter: var(--blur);
  border: 1px solid var(--border);
  border-radius: var(--radius-lg);
  box-shadow: var(--shadow);
  transition: box-shadow var(--transition), transform var(--transition);
}
.about-card:hover {
  box-shadow: var(--shadow-lg);
  transform: translateY(-2px);
}

.about-card h3 { color: var(--text); margin-bottom: 0.75rem; }
.about-card p  { font-size: 0.95rem; color: var(--text-muted); }

.about-full {
  grid-column: 1 / -1;
}

/* ============================================================
   RESEARCH
   ============================================================ */
.research-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(300px, 1fr));
  gap: 1.25rem;
}

.research-card {
  padding: 1.75rem;
  background: var(--bg-card);
  backdrop-filter: var(--blur);
  -webkit-backdrop-filter: var(--blur);
  border: 1px solid var(--border);
  border-radius: var(--radius-lg);
  box-shadow: var(--shadow);
  transition: box-shadow var(--transition), transform var(--transition),
              border-color var(--transition);
}
.research-card:hover {
  box-shadow: var(--shadow-lg);
  transform: translateY(-3px);
  border-color: var(--accent);
}

.research-icon {
  font-size: 1.75rem;
  margin-bottom: 0.875rem;
  line-height: 1;
}

.research-card h3 {
  color: var(--text);
  margin-bottom: 0.5rem;
  font-size: 1.05rem;
}

.research-card p {
  font-size: 0.875rem;
  line-height: 1.6;
  color: var(--text-muted);
}

/* ============================================================
   PUBLICATIONS
   ============================================================ */
.pub-meta {
  font-size: 0.85rem;
  color: var(--text-subtle);
  margin-bottom: 1.75rem;
}

.pub-meta a { color: var(--accent); }
.pub-meta span { margin: 0 0.3rem; }

/* ── Filter containers ─── */
.filter-row {
  display: flex;
  flex-wrap: wrap;
  gap: 0.5rem;
  margin-bottom: 1rem;
}

.filter-label {
  font-size: 0.75rem;
  font-weight: 600;
  letter-spacing: 0.07em;
  text-transform: uppercase;
  color: var(--text-subtle);
  align-self: center;
  flex-shrink: 0;
  margin-right: 0.25rem;
}

/* Type pills */
.type-pill {
  padding: 0.4rem 1rem;
  border-radius: var(--radius-full);
  font-size: 0.82rem;
  font-weight: 500;
  cursor: pointer;
  border: 1px solid var(--border-strong);
  background: var(--bg-card);
  color: var(--text-muted);
  transition: background var(--transition-fast), color var(--transition-fast),
              border-color var(--transition-fast), box-shadow var(--transition-fast);
  white-space: nowrap;
  user-select: none;
}
.type-pill:hover {
  border-color: var(--accent);
  color: var(--accent);
}
.type-pill.active {
  background: var(--grad-text);
  color: #fff;
  border-color: transparent;
  box-shadow: 0 2px 10px rgba(124, 58, 237, 0.35);
}

/* Topic chips */
.topic-chip {
  padding: 0.28rem 0.65rem;
  border-radius: var(--radius-xs);
  font-size: 0.75rem;
  font-weight: 500;
  cursor: pointer;
  border: 1px solid var(--border);
  background: var(--bg-chip);
  color: var(--text-muted);
  transition: background var(--transition-fast), color var(--transition-fast),
              border-color var(--transition-fast);
  white-space: nowrap;
  user-select: none;
}
.topic-chip::before { content: '#'; opacity: 0.55; margin-right: 1px; }
.topic-chip:hover {
  border-color: var(--chip-active-bg);
  color: var(--chip-active-bg);
}
.topic-chip.active {
  background: var(--chip-active-bg);
  color: var(--chip-active-text);
  border-color: transparent;
}

.pub-count {
  font-size: 0.85rem;
  color: var(--text-subtle);
  margin-bottom: 1.25rem;
}

/* ── Publication list ─── */
#pub-list {
  display: flex;
  flex-direction: column;
  gap: 0.75rem;
}

.pub-year-header {
  font-size: 1.5rem;
  font-weight: 700;
  color: var(--accent);
  margin-top: 3.5rem;
  margin-bottom: 1.25rem;
  padding-bottom: 0.5rem;
  border-bottom: 2px solid var(--accent-bg);
  width: 100%;
}

/* First header shouldn't have top margin */
.pub-year-header:first-child {
  margin-top: 0;
}

.pub-card {
  display: flex;
  gap: 1rem;
  padding: 1.1rem 1.25rem;
  background: var(--bg-card);
  backdrop-filter: var(--blur);
  -webkit-backdrop-filter: var(--blur);
  border: 1px solid var(--border);
  border-radius: var(--radius-md);
  box-shadow: var(--shadow-sm);
  transition: box-shadow var(--transition), border-color var(--transition),
              transform var(--transition-fast);
  animation: fadeIn 0.3s ease;
}
.pub-card:hover {
  box-shadow: var(--shadow);
  border-color: var(--border-strong);
  transform: translateX(2px);
}

@keyframes fadeIn {
  from { opacity: 0; transform: translateY(6px); }
  to   { opacity: 1; transform: translateY(0); }
}

/* Venue badge (left column) */
.pub-badge {
  flex-shrink: 0;
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 0.3rem;
  min-width: 4.5rem;
}

.badge-pill {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  padding: 0.3rem 0.55rem;
  border-radius: var(--radius-sm);
  font-size: 0.7rem;
  font-weight: 700;
  letter-spacing: 0.04em;
  /* text-transform: uppercase; */
  line-height: 1.2;
  text-align: center;
  min-width: 3rem;
}

.badge-conf     { background: var(--badge-conf-bg);     color: var(--badge-conf-text); }
.badge-journal  { background: var(--badge-journal-bg);  color: var(--badge-journal-text); }
.badge-workshop { background: var(--badge-workshop-bg); color: var(--badge-workshop-text); }
.badge-preprint { background: var(--badge-preprint-bg); color: var(--badge-preprint-text); }
.badge-other    { background: var(--badge-other-bg);    color: var(--badge-other-text); }

.badge-year {
  font-size: 0.7rem;
  color: var(--text-subtle);
  font-weight: 500;
}

/* Paper body */
.pub-body { flex: 1; min-width: 0; }

.pub-title {
  font-size: 0.95rem;
  font-weight: 600;
  color: var(--text);
  line-height: 1.45;
  margin-bottom: 0.3rem;
}

.pub-title a {
  color: inherit;
  text-decoration: none;
}
.pub-title a:hover {
  color: var(--accent);
  text-decoration: underline;
}

.pub-doi {
  display: inline-flex;
  align-items: center;
  gap: 0.2rem;
  font-size: 0.72rem;
  font-weight: 600;
  color: var(--accent);
  /* text-transform: uppercase; */
  letter-spacing: 0.05em;
  transition: color var(--transition), opacity var(--transition);
  opacity: 0.8;
}
.pub-doi:hover {
  opacity: 1;
  text-decoration: underline !important;
}

.pub-authors {
  font-size: 0.82rem;
  color: var(--text-muted);
  margin-bottom: 0.35rem;
  line-height: 1.5;
}

.pub-authors .me { font-weight: 600; color: var(--accent); }

.pub-venue-line {
  font-size: 0.8rem;
  color: var(--text-subtle);
  margin-bottom: 0.5rem;
}

.pub-chips {
  display: flex;
  flex-wrap: wrap;
  gap: 0.35rem;
}

.pub-chip {
  padding: 0.18rem 0.5rem;
  border-radius: var(--radius-xs);
  font-size: 0.68rem;
  font-weight: 500;
  background: var(--bg-chip);
  color: var(--text-muted);
  border: 1px solid var(--border);
  cursor: pointer;
  transition: background var(--transition-fast), color var(--transition-fast);
  user-select: none;
}
.pub-chip::before { content: '#'; opacity: 0.55; }
.pub-chip:hover,
.pub-chip.active {
  background: var(--chip-active-bg);
  color: var(--chip-active-text);
  border-color: transparent;
}

/* No results */
.pub-empty {
  text-align: center;
  padding: 3rem 1rem;
  color: var(--text-muted);
  font-size: 0.95rem;
}

/* ============================================================
   TEACHING
   ============================================================ */
.teaching-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(400px, 1fr));
  gap: 1.25rem;
}

.teaching-card {
  padding: 1.5rem;
  background: var(--bg-card);
  backdrop-filter: var(--blur);
  -webkit-backdrop-filter: var(--blur);
  border: 1px solid var(--border);
  border-radius: var(--radius-lg);
  box-shadow: var(--shadow);
  transition: box-shadow var(--transition), transform var(--transition);
}
.teaching-card:hover {
  box-shadow: var(--shadow-lg);
  transform: translateY(-2px);
}

.teaching-card h3 {
  color: var(--text);
  font-size: 1rem;
  margin-bottom: 0.35rem;
}

.teaching-card p {
  font-size: 0.875rem;
  color: var(--text-muted);
  margin-bottom: 0.75rem;
}

.badge-lang {
  display: inline-block;
  padding: 0.15rem 0.5rem;
  border-radius: var(--radius-xs);
  font-size: 0.68rem;
  font-weight: 700;
  letter-spacing: 0.05em;
  text-transform: uppercase;
  background: var(--accent-bg);
  color: var(--accent);
  margin-bottom: 0.5rem;
}

.teaching-link {
  display: inline-flex;
  align-items: center;
  gap: 0.3rem;
  font-size: 0.82rem;
  font-weight: 500;
  color: var(--accent);
}
.teaching-link:hover { text-decoration: underline; }
.teaching-link::after { content: ' ↗'; opacity: 0.7; }

/* ============================================================
   CONTACT
   ============================================================ */
.contact-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 2rem;
}

.contact-block {
  padding: 1.75rem;
  background: var(--bg-card);
  backdrop-filter: var(--blur);
  -webkit-backdrop-filter: var(--blur);
  border: 1px solid var(--border);
  border-radius: var(--radius-lg);
  box-shadow: var(--shadow);
}

.contact-block h3 {
  color: var(--text);
  margin-bottom: 0.875rem;
  font-size: 1rem;
}

.contact-block p,
.contact-block address {
  font-size: 0.9rem;
  color: var(--text-muted);
  font-style: normal;
  line-height: 1.8;
}

.contact-block a { color: var(--accent); }

/* Social links */
.social-links {
  display: flex;
  flex-wrap: wrap;
  gap: 0.6rem;
  margin-top: 0.75rem;
}

.social-link {
  display: inline-flex;
  align-items: center;
  gap: 0.3rem;
  padding: 0.4rem 0.875rem;
  border-radius: var(--radius-full);
  font-size: 0.8rem;
  font-weight: 500;
  background: var(--bg-chip);
  color: var(--text-muted);
  border: 1px solid var(--border);
  text-decoration: none !important;
  transition: background var(--transition-fast), color var(--transition-fast),
              border-color var(--transition-fast);
}
.social-link:hover {
  background: var(--accent-bg);
  color: var(--accent);
  border-color: var(--accent);
}

/* ============================================================
   FOOTER
   ============================================================ */
footer {
  padding-block: 2rem;
  border-top: 1px solid var(--border);
  text-align: center;
}
footer p {
  font-size: 0.8rem;
  color: var(--text-subtle);
}
footer a { color: var(--accent); }

/* ============================================================
   UTILITY CLASSES
   ============================================================ */
.visually-hidden {
  position: absolute; width: 1px; height: 1px; overflow: hidden;
  clip: rect(0,0,0,0); white-space: nowrap; border: 0;
}

.text-muted  { color: var(--text-muted); }
.text-subtle { color: var(--text-subtle); }
.text-accent { color: var(--accent); }

/* ============================================================
   RESPONSIVE
   ============================================================ */
@media (max-width: 900px) {
  .hero-content {
    grid-template-columns: 1fr;
    text-align: center;
  }
  .hero-photo {
    order: -1;
    display: flex;
    justify-content: center;
  }
  .hero-stats { justify-content: center; }
  .hero-links { justify-content: center; }
  .hero-bio   { margin-inline: auto; }

  .about-grid   { grid-template-columns: 1fr; }
  .contact-grid { grid-template-columns: 1fr; }
}

@media (max-width: 640px) {
  :root { --nav-h: 3.25rem; }

  .section { padding-block: 3.5rem; }

  .hero { padding-block: 2rem 3rem; }

  .photo-ring { width: clamp(160px, 50vw, 200px); height: clamp(160px, 50vw, 200px); }

  .hero-stats { gap: 1rem 2rem; }

  .stat-value { font-size: 1.3rem; }

  /* Nav: horizontally scrollable on very small screens */
  .nav-pill {
    width: calc(100vw - 2rem);
    max-width: calc(100vw - 2rem);
  }

  /* Filter rows: horizontal carousel */
  .filter-row {
    flex-wrap: nowrap;
    overflow-x: auto;
    scrollbar-width: none;
    padding-bottom: 4px;
  }
  .filter-row::-webkit-scrollbar { display: none; }

  .pub-card {
    flex-direction: column;
    gap: 0.6rem;
  }
  .pub-badge {
    flex-direction: row;
    min-width: unset;
    gap: 0.5rem;
  }

  .research-grid { grid-template-columns: 1fr; }
  .teaching-grid { grid-template-columns: 1fr; }
}