/* ============================================================
   CEANNA CHEUNG — PERSONAL WEBSITE
   Shared Stylesheet (style.css)
   ▸ Edit CSS variables at the top to restyle the entire site
   ============================================================ */

/* ── Design Tokens ── */
:root {
  --color-bg:         #F8F7F4;
  --color-surface:    #FFFFFF;
  --color-navy:       #16213E;
  --color-text:       #1C1C2E;
  --color-muted:      #5A6478;
  --color-teal:       #0D7377;
  --color-teal-light: #14A8AC;
  --color-sand:       #E8E2D5;
  --color-sand-dark:  #D4CCBE;
  --color-border:     #E2DDD6;

  --font-display: 'Playfair Display', Georgia, serif;
  --font-body:    'Source Serif 4', Georgia, serif;
  --font-mono:    'JetBrains Mono', 'Courier New', monospace;

  --radius-sm:  4px;
  --radius-md:  8px;
  --radius-lg:  16px;

  --shadow-sm: 0 1px 3px rgba(22,33,62,0.06), 0 1px 2px rgba(22,33,62,0.04);
  --shadow-md: 0 4px 12px rgba(22,33,62,0.08), 0 2px 4px rgba(22,33,62,0.04);
  --shadow-lg: 0 10px 30px rgba(22,33,62,0.10), 0 4px 8px rgba(22,33,62,0.06);

  --transition: 0.25s ease;
  --max-width: 1100px;
}

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

html { scroll-behavior: smooth; font-size: 16px; }

body {
  font-family: var(--font-body);
  background-color: var(--color-bg);
  color: var(--color-text);
  line-height: 1.75;
  -webkit-font-smoothing: antialiased;
}

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

a {
  color: var(--color-teal);
  text-decoration: none;
  transition: color var(--transition);
}
a:hover { color: var(--color-teal-light); }

/* ── Layout ── */
.container {
  max-width: var(--max-width);
  margin: 0 auto;
  padding: 0 clamp(1.25rem, 5vw, 2.5rem);
}

.section {
  padding: clamp(4rem, 9vw, 7rem) 0;
}

.section--alt { background-color: var(--color-surface); }

/* ── Section Typography ── */
.section-label {
  font-family: var(--font-mono);
  font-size: 0.75rem;
  font-weight: 300;
  letter-spacing: 0.15em;
  color: var(--color-teal);
  text-transform: uppercase;
  margin-bottom: 0.75rem;
}

.section-heading {
  font-family: var(--font-display);
  font-size: clamp(1.75rem, 4vw, 2.5rem);
  font-weight: 600;
  color: var(--color-navy);
  line-height: 1.2;
  margin-bottom: 1rem;
}

.section-subheading {
  font-size: 1.0625rem;
  color: var(--color-muted);
  max-width: 54ch;
  margin-bottom: 3rem;
}

.section-rule {
  width: 3rem;
  height: 2px;
  background: var(--color-teal);
  margin-bottom: 3rem;
  border: none;
}

/* ── Scroll Reveal ── */
.reveal {
  opacity: 0;
  transform: translateY(24px);
  transition: opacity 0.65s ease, transform 0.65s ease;
}
.reveal.visible { opacity: 1; transform: translateY(0); }
.reveal-delay-1 { transition-delay: 0.1s; }
.reveal-delay-2 { transition-delay: 0.2s; }
.reveal-delay-3 { transition-delay: 0.3s; }
.reveal-delay-4 { transition-delay: 0.4s; }

/* ── Navigation ── */
.nav {
  position: fixed;
  top: 0; left: 0; right: 0;
  z-index: 1000;
  background: rgba(248, 247, 244, 0.92);
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
  border-bottom: 1px solid transparent;
  transition: border-color var(--transition);
}
.nav.scrolled { border-color: var(--color-border); }

.nav__inner {
  max-width: var(--max-width);
  margin: 0 auto;
  padding: 0 clamp(1.25rem, 5vw, 2.5rem);
  height: 64px;
  display: flex;
  align-items: center;
  justify-content: space-between;
}

.nav__logo {
  font-family: var(--font-display);
  font-size: 1.125rem;
  font-weight: 600;
  color: var(--color-navy);
  letter-spacing: 0.01em;
  display: flex;
  align-items: center;
  gap: 0.6rem;
}
.nav__logo img {
  width: 32px;
  height: 32px;
  border-radius: 50%;
  object-fit: cover;
  border: 1.5px solid var(--color-sand-dark);
}
.nav__logo span { color: var(--color-teal); }

.nav__links {
  display: flex;
  gap: 2rem;
  list-style: none;
}

.nav__links a {
  font-family: var(--font-body);
  font-size: 0.875rem;
  color: var(--color-muted);
  font-weight: 400;
  position: relative;
  transition: color var(--transition);
}
.nav__links a::after {
  content: '';
  position: absolute;
  bottom: -3px; left: 0;
  width: 0; height: 1px;
  background: var(--color-teal);
  transition: width var(--transition);
}
.nav__links a:hover,
.nav__links a.active { color: var(--color-navy); }
.nav__links a:hover::after,
.nav__links a.active::after { width: 100%; }

.nav__toggle {
  display: none;
  flex-direction: column;
  gap: 5px;
  cursor: pointer;
  padding: 4px;
  background: none;
  border: none;
}
.nav__toggle span {
  display: block;
  width: 22px; height: 1.5px;
  background: var(--color-navy);
  transition: all var(--transition);
}
.nav__toggle.open span:nth-child(1) { transform: translateY(6.5px) rotate(45deg); }
.nav__toggle.open span:nth-child(2) { opacity: 0; }
.nav__toggle.open span:nth-child(3) { transform: translateY(-6.5px) rotate(-45deg); }

/* ── Buttons ── */
.btn {
  display: inline-flex;
  align-items: center;
  gap: 0.5rem;
  padding: 0.75rem 1.5rem;
  border-radius: var(--radius-sm);
  font-family: var(--font-body);
  font-size: 0.9rem;
  font-weight: 500;
  cursor: pointer;
  transition: all var(--transition);
  white-space: nowrap;
  text-decoration: none;
}
.btn--primary {
  background: var(--color-teal);
  color: #fff;
  border: 1px solid var(--color-teal);
}
.btn--primary:hover {
  background: var(--color-navy);
  border-color: var(--color-navy);
  color: #fff;
  transform: translateY(-1px);
  box-shadow: var(--shadow-md);
}
.btn--secondary {
  background: transparent;
  color: var(--color-navy);
  border: 1px solid var(--color-sand-dark);
}
.btn--secondary:hover {
  border-color: var(--color-teal);
  color: var(--color-teal);
  transform: translateY(-1px);
}

/* ── Badges & Tags ── */
.badge {
  display: inline-block;
  background: rgba(13,115,119,0.08);
  color: var(--color-teal);
  border: 1px solid rgba(13,115,119,0.2);
  border-radius: 100px;
  padding: 0.2rem 0.75rem;
  font-family: var(--font-mono);
  font-size: 0.7rem;
  letter-spacing: 0.05em;
  margin-top: 0.75rem;
  margin-right: 0.4rem;
}

/* ── Placeholder notes (remove once you fill in content) ── */
.placeholder-note {
  display: inline-block;
  background: rgba(248,164,21,0.12);
  color: #8a5c00;
  border: 1px dashed rgba(248,164,21,0.5);
  border-radius: var(--radius-sm);
  padding: 0.15rem 0.5rem;
  font-family: var(--font-mono);
  font-size: 0.7rem;
  letter-spacing: 0.03em;
  vertical-align: middle;
  margin-left: 0.35rem;
}

/* ── Timeline (Education & Experience) ── */
.timeline {
  position: relative;
  padding-left: 2.5rem;
}
.timeline::before {
  content: '';
  position: absolute;
  left: 7px; top: 8px; bottom: 0;
  width: 1px;
  background: var(--color-border);
}
.timeline-item {
  position: relative;
  margin-bottom: 3rem;
}
.timeline-item:last-child { margin-bottom: 0; }
.timeline-item::before {
  content: '';
  position: absolute;
  left: -2.5rem; top: 10px;
  width: 14px; height: 14px;
  border-radius: 50%;
  background: var(--color-teal);
  border: 3px solid var(--color-bg);
  box-shadow: 0 0 0 1px var(--color-teal);
}
.timeline-item--alt::before {
  background: var(--color-surface);
  border-color: var(--color-teal);
}
.timeline-item__date {
  font-family: var(--font-mono);
  font-size: 0.75rem;
  color: var(--color-teal);
  letter-spacing: 0.08em;
  margin-bottom: 0.4rem;
}
.timeline-item__title {
  font-family: var(--font-display);
  font-size: 1.2rem;
  font-weight: 600;
  color: var(--color-navy);
  margin-bottom: 0.3rem;
}
.timeline-item__subtitle {
  font-size: 0.9375rem;
  color: var(--color-muted);
  margin-bottom: 0.75rem;
}
.timeline-item__body {
  font-size: 0.9375rem;
  color: var(--color-text);
  line-height: 1.7;
}
.timeline-item__body ul { padding-left: 1.25rem; margin-top: 0.5rem; }
.timeline-item__body li { margin-bottom: 0.35rem; }

/* ── Research Cards ── */
.research-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(260px, 1fr));
  gap: 1.5rem;
}
.research-card {
  background: var(--color-surface);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-lg);
  padding: 2rem 1.75rem;
  transition: box-shadow var(--transition), transform var(--transition);
  position: relative;
  overflow: hidden;
}
.research-card::before {
  content: '';
  position: absolute;
  top: 0; left: 0; right: 0;
  height: 3px;
  background: linear-gradient(90deg, var(--color-teal), var(--color-teal-light));
  transform: scaleX(0);
  transform-origin: left;
  transition: transform var(--transition);
}
.research-card:hover { box-shadow: var(--shadow-md); transform: translateY(-3px); }
.research-card:hover::before { transform: scaleX(1); }
.research-card__icon { font-size: 1.75rem; margin-bottom: 1rem; display: block; }
.research-card__title {
  font-family: var(--font-display);
  font-size: 1.0625rem;
  font-weight: 600;
  color: var(--color-navy);
  margin-bottom: 0.6rem;
}
.research-card__desc {
  font-size: 0.9rem;
  color: var(--color-muted);
  line-height: 1.65;
}

/* ── Publications ── */
.publications-list { display: flex; flex-direction: column; gap: 2rem; }
.pub-item {
  display: grid;
  grid-template-columns: auto 1fr;
  gap: 1.5rem;
  padding: 1.75rem;
  background: var(--color-surface);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-md);
  transition: box-shadow var(--transition);
}
.pub-item:hover { box-shadow: var(--shadow-md); }
.pub-item__number {
  font-family: var(--font-mono);
  font-size: 1.5rem;
  color: var(--color-sand-dark);
  font-weight: 300;
  line-height: 1;
  padding-top: 4px;
  min-width: 2rem;
}
.pub-item__title {
  font-family: var(--font-display);
  font-size: 1.0625rem;
  font-weight: 600;
  color: var(--color-navy);
  line-height: 1.4;
  margin-bottom: 0.5rem;
}
.pub-item__authors {
  font-size: 0.875rem;
  color: var(--color-muted);
  margin-bottom: 0.4rem;
}
.pub-item__authors strong { color: var(--color-teal); font-weight: 500; }
.pub-item__journal {
  font-size: 0.875rem;
  font-style: italic;
  color: var(--color-text);
  margin-bottom: 0.75rem;
}
.pub-item__links { display: flex; gap: 0.75rem; flex-wrap: wrap; }
.pub-link {
  font-family: var(--font-mono);
  font-size: 0.7rem;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  padding: 0.3rem 0.8rem;
  border: 1px solid var(--color-border);
  border-radius: var(--radius-sm);
  color: var(--color-muted);
  transition: all var(--transition);
}
.pub-link:hover { border-color: var(--color-teal); color: var(--color-teal); }
.pub-tag {
  display: inline-block;
  font-family: var(--font-mono);
  font-size: 0.65rem;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  padding: 0.2rem 0.6rem;
  border-radius: 100px;
  margin-left: 0.5rem;
  vertical-align: middle;
}
.pub-tag--published { background: rgba(13,115,119,0.1); color: var(--color-teal); border: 1px solid rgba(13,115,119,0.25); }
.pub-tag--review    { background: rgba(248,164,21,0.1); color: #A06000; border: 1px solid rgba(248,164,21,0.3); }
.pub-tag--prep      { background: rgba(90,100,120,0.08); color: var(--color-muted); border: 1px solid var(--color-border); }

/* ── Project Cards ── */
.projects-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(320px, 1fr));
  gap: 1.75rem;
}
.project-card {
  background: var(--color-surface);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-lg);
  overflow: hidden;
  transition: box-shadow var(--transition), transform var(--transition);
}
.project-card:hover { box-shadow: var(--shadow-lg); transform: translateY(-4px); }
.project-card__header {
  background: linear-gradient(135deg, var(--color-navy) 0%, #253568 100%);
  padding: 1.75rem;
  position: relative;
  overflow: hidden;
}
.project-card__header::after {
  content: attr(data-label);
  position: absolute;
  bottom: -10px; right: -5px;
  font-family: var(--font-mono);
  font-size: 4.5rem;
  font-weight: 300;
  color: rgba(255,255,255,0.05);
  letter-spacing: -0.05em;
  pointer-events: none;
  line-height: 1;
}
.project-card__tag {
  font-family: var(--font-mono);
  font-size: 0.65rem;
  letter-spacing: 0.12em;
  text-transform: uppercase;
  color: rgba(20,168,172,0.85);
  margin-bottom: 0.6rem;
}
.project-card__title {
  font-family: var(--font-display);
  font-size: 1.125rem;
  color: #fff;
  font-weight: 600;
  line-height: 1.3;
}
.project-card__body { padding: 1.5rem 1.75rem; }
.project-card__desc {
  font-size: 0.9375rem;
  color: var(--color-muted);
  line-height: 1.7;
  margin-bottom: 1.25rem;
}
.project-card__tech { display: flex; gap: 0.5rem; flex-wrap: wrap; }
.tech-tag {
  font-family: var(--font-mono);
  font-size: 0.7rem;
  padding: 0.2rem 0.65rem;
  background: var(--color-sand);
  color: var(--color-text);
  border-radius: var(--radius-sm);
  letter-spacing: 0.04em;
}

/* ── Awards ── */
.awards-list { display: flex; flex-direction: column; gap: 1rem; }
.award-item {
  display: flex;
  gap: 1.25rem;
  align-items: flex-start;
  padding: 1.25rem 1.5rem;
  background: var(--color-surface);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-md);
  transition: box-shadow var(--transition);
}
.award-item:hover { box-shadow: var(--shadow-sm); }
.award-item__icon { font-size: 1.375rem; flex-shrink: 0; margin-top: 2px; }
.award-item__title {
  font-size: 1rem;
  font-weight: 600;
  color: var(--color-navy);
  margin-bottom: 0.2rem;
}
.award-item__meta { font-size: 0.875rem; color: var(--color-muted); }

/* ── Skills ── */
.skills-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(260px, 1fr));
  gap: 2rem;
}
.skills-group__label {
  font-family: var(--font-mono);
  font-size: 0.7rem;
  letter-spacing: 0.14em;
  text-transform: uppercase;
  color: var(--color-teal);
  margin-bottom: 1rem;
  padding-bottom: 0.5rem;
  border-bottom: 1px solid var(--color-border);
}
.skills-tags { display: flex; flex-wrap: wrap; gap: 0.5rem; }
.skill-tag {
  font-family: var(--font-mono);
  font-size: 0.78rem;
  padding: 0.35rem 0.85rem;
  border: 1px solid var(--color-border);
  border-radius: 100px;
  color: var(--color-text);
  background: var(--color-surface);
  transition: all var(--transition);
  letter-spacing: 0.02em;
}
.skill-tag:hover {
  border-color: var(--color-teal);
  color: var(--color-teal);
  background: rgba(13,115,119,0.04);
}

/* ── Gallery ── */
.gallery-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 1rem;
}
.gallery-item {
  position: relative;
  overflow: hidden;
  border-radius: var(--radius-md);
  background: var(--color-sand);
  aspect-ratio: 4/3;
}
.gallery-item:first-child { grid-column: span 2; aspect-ratio: 16/9; }
.gallery-item img {
  width: 100%; height: 100%;
  object-fit: cover;
  transition: transform 0.5s ease;
}
.gallery-item:hover img { transform: scale(1.04); }
.gallery-item__overlay {
  position: absolute; inset: 0;
  background: linear-gradient(to top, rgba(22,33,62,0.7) 0%, transparent 50%);
  opacity: 0;
  transition: opacity var(--transition);
  display: flex;
  align-items: flex-end;
  padding: 1rem;
}
.gallery-item:hover .gallery-item__overlay { opacity: 1; }
.gallery-item__caption { font-size: 0.8rem; color: rgba(255,255,255,0.9); font-style: italic; }
.gallery-placeholder {
  width: 100%; height: 100%;
  display: flex; flex-direction: column;
  align-items: center; justify-content: center;
  gap: 0.5rem;
  color: var(--color-muted);
  font-family: var(--font-mono);
  font-size: 0.65rem;
  text-align: center;
  letter-spacing: 0.04em;
  padding: 1rem;
  background: var(--color-sand);
}
.gallery-placeholder svg { width: 32px; height: 32px; opacity: 0.35; }

/* ── Contact ── */
.contact__wrapper {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: clamp(2rem, 6vw, 5rem);
  align-items: start;
}
.contact__text p {
  font-size: 1rem;
  color: var(--color-muted);
  line-height: 1.8;
  margin-bottom: 1.5rem;
}
.contact__email-link {
  font-family: var(--font-display);
  font-size: 1.375rem;
  font-weight: 600;
  color: var(--color-navy);
  display: inline-block;
  margin-bottom: 2rem;
  transition: color var(--transition);
}
.contact__email-link:hover { color: var(--color-teal); }
.contact__socials { display: flex; flex-direction: column; gap: 0.75rem; }
.social-link {
  display: flex;
  align-items: center;
  gap: 1rem;
  padding: 0.875rem 1.25rem;
  background: var(--color-surface);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-md);
  transition: all var(--transition);
  color: var(--color-text);
  text-decoration: none;
}
.social-link:hover {
  border-color: var(--color-teal);
  box-shadow: var(--shadow-sm);
  transform: translateX(4px);
  color: var(--color-teal);
}
.social-link__icon {
  width: 36px; height: 36px;
  border-radius: var(--radius-sm);
  background: var(--color-sand);
  display: flex; align-items: center; justify-content: center;
  flex-shrink: 0;
  font-size: 0.8rem;
  font-family: var(--font-mono);
  font-weight: 600;
  color: var(--color-navy);
}
.social-link__label { font-size: 0.9rem; font-weight: 500; }
.social-link__sub { font-size: 0.8rem; color: var(--color-muted); margin-top: 0.1rem; }
.social-link__arrow { margin-left: auto; color: var(--color-muted); font-size: 0.75rem; }
.contact__form {
  background: var(--color-surface);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-lg);
  padding: 2rem;
}
.form-group { margin-bottom: 1.25rem; }
.form-label {
  display: block;
  font-family: var(--font-mono);
  font-size: 0.7rem;
  letter-spacing: 0.1em;
  text-transform: uppercase;
  color: var(--color-muted);
  margin-bottom: 0.4rem;
}
.form-input, .form-textarea {
  width: 100%;
  padding: 0.75rem 1rem;
  border: 1px solid var(--color-border);
  border-radius: var(--radius-sm);
  font-family: var(--font-body);
  font-size: 0.9375rem;
  color: var(--color-text);
  background: var(--color-bg);
  transition: border-color var(--transition), box-shadow var(--transition);
  outline: none;
}
.form-input:focus, .form-textarea:focus {
  border-color: var(--color-teal);
  box-shadow: 0 0 0 3px rgba(13,115,119,0.1);
}
.form-textarea { min-height: 120px; resize: vertical; }

/* ── Page Hero Banner (for inner pages) ── */
.page-hero {
  background: var(--color-navy);
  padding: clamp(5rem, 10vw, 8rem) 0 clamp(3rem, 6vw, 5rem);
  position: relative;
  overflow: hidden;
}
.page-hero::before {
  content: '';
  position: absolute;
  inset: 0;
  background-image: url("data:image/svg+xml,%3Csvg viewBox='0 0 600 400' xmlns='http://www.w3.org/2000/svg'%3E%3Cdefs%3E%3Cpattern id='h' x='0' y='0' width='60' height='52' patternUnits='userSpaceOnUse'%3E%3Cpolygon points='15,2 45,2 58,26 45,50 15,50 2,26' fill='none' stroke='%230D7377' stroke-width='0.8' opacity='0.4'/%3E%3C/pattern%3E%3C/defs%3E%3Crect width='600' height='400' fill='url(%23h)'/%3E%3C/svg%3E");
  opacity: 0.4;
}
.page-hero__content { position: relative; z-index: 1; }
.page-hero__label {
  font-family: var(--font-mono);
  font-size: 0.75rem;
  letter-spacing: 0.18em;
  color: var(--color-teal-light);
  text-transform: uppercase;
  margin-bottom: 1rem;
  display: flex;
  align-items: center;
  gap: 0.75rem;
}
.page-hero__label::before {
  content: '';
  display: inline-block;
  width: 2rem; height: 1px;
  background: var(--color-teal-light);
}
.page-hero__title {
  font-family: var(--font-display);
  font-size: clamp(2rem, 5vw, 3.25rem);
  font-weight: 700;
  color: #fff;
  line-height: 1.1;
  letter-spacing: -0.02em;
  margin-bottom: 1rem;
}
.page-hero__sub {
  font-size: 1.0625rem;
  color: rgba(255,255,255,0.55);
  max-width: 48ch;
}

/* ── Footer ── */
.footer {
  background: var(--color-navy);
  padding: 3.5rem 0;
  position: relative;
  overflow: hidden;
}
.footer::before {
  content: 'CC';
  position: absolute;
  right: clamp(2rem, 8vw, 6rem);
  bottom: -1rem;
  font-family: var(--font-display);
  font-size: clamp(8rem, 18vw, 14rem);
  font-weight: 700;
  color: rgba(255,255,255,0.035);
  line-height: 1;
  pointer-events: none;
  letter-spacing: -0.04em;
}
.footer__inner {
  position: relative; z-index: 1;
  display: flex;
  justify-content: space-between;
  align-items: center;
  flex-wrap: wrap;
  gap: 1.5rem;
}
.footer__name {
  font-family: var(--font-display);
  font-size: 1.125rem;
  color: #fff;
  font-weight: 500;
}
.footer__name span { color: var(--color-teal-light); }
.footer__links { display: flex; gap: 1.5rem; list-style: none; }
.footer__links a {
  font-family: var(--font-body);
  font-size: 0.85rem;
  color: rgba(255,255,255,0.45);
  transition: color var(--transition);
}
.footer__links a:hover { color: rgba(255,255,255,0.85); }
.footer__copy {
  font-family: var(--font-mono);
  font-size: 0.7rem;
  color: rgba(255,255,255,0.3);
  letter-spacing: 0.06em;
  width: 100%;
  margin-top: 2rem;
  padding-top: 1.5rem;
  border-top: 1px solid rgba(255,255,255,0.06);
}

/* ── Responsive ── */
@media (max-width: 640px) {
  .nav__links {
    display: none;
    position: fixed;
    top: 64px; left: 0; right: 0;
    background: rgba(248,247,244,0.97);
    flex-direction: column;
    padding: 1.5rem clamp(1.25rem, 5vw, 2.5rem);
    gap: 0;
    border-bottom: 1px solid var(--color-border);
    backdrop-filter: blur(12px);
  }
  .nav__links.open { display: flex; }
  .nav__links li { border-bottom: 1px solid var(--color-border); }
  .nav__links li:last-child { border-bottom: none; }
  .nav__links a { display: block; padding: 0.85rem 0; font-size: 0.9rem; color: var(--color-text); }
  .nav__links a::after { display: none; }
  .nav__toggle { display: flex; }

  .contact__wrapper { grid-template-columns: 1fr; }
  .pub-item { grid-template-columns: 1fr; gap: 0.5rem; }
  .gallery-grid { grid-template-columns: 1fr; }
  .gallery-item:first-child { grid-column: span 1; aspect-ratio: 4/3; }
}

@media (max-width: 768px) {
  .contact__wrapper { grid-template-columns: 1fr; }
  .research-grid { grid-template-columns: 1fr 1fr; }
}

@media (max-width: 500px) {
  .research-grid { grid-template-columns: 1fr; }
  .projects-grid { grid-template-columns: 1fr; }
}