:root {
  --orange: #E77500;
  --black: #1a1a1a;
  --gray-dark: #444;
  --gray-mid: #888;
  --gray-light: #f6f6f6;
  --border: #e2e2e2;
  --link: #2a5db0;
  --max-width: 900px;
  --font: system-ui, -apple-system, BlinkMacSystemFont, 'Segoe UI', sans-serif;
  --font-serif: 'EB Garamond', Georgia, serif;
}

*, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }
html { font-size: 16px; }
body { font-family: var(--font); color: var(--black); background: #fff; line-height: 1.7; }
a { color: var(--link); text-decoration: none; }
a:hover { text-decoration: underline; }
img { max-width: 100%; display: block; }

.site-wrapper { max-width: var(--max-width); margin: 0 auto; padding: 0 24px; }

header { border-bottom: 3px solid var(--orange); background: #fff; position: sticky; top: 0; z-index: 100; }
.header-inner {
  max-width: var(--max-width); margin: 0 auto; padding: 14px 24px 0;
  display: flex; align-items: baseline; justify-content: space-between; flex-wrap: wrap; gap: 6px;
}
.site-title { font-size: 1rem; font-weight: 700; }
.site-title a { color: var(--black); }
.site-title a:hover { color: var(--orange); text-decoration: none; }
nav { display: flex; }
nav a {
  display: inline-block; padding: 9px 14px 12px;
  font-size: 0.85rem; font-weight: 500; color: var(--gray-dark);
  border-bottom: 3px solid transparent; margin-bottom: -3px;
  transition: color 0.15s, border-color 0.15s;
}
nav a:hover { color: var(--orange); border-bottom-color: var(--orange); text-decoration: none; }
nav a.active { color: var(--orange); border-bottom-color: var(--orange); font-weight: 600; }

main { max-width: var(--max-width); margin: 0 auto; padding: 44px 24px 80px; }

.home-hero { display: flex; gap: 36px; align-items: flex-start; }
.home-hero img {
  width: 185px; height: 230px; object-fit: cover; object-position: center center;
  border-radius: 4px; flex-shrink: 0; border: 1px solid var(--border);
}
.home-bio h1 { font-family: var(--font-serif); font-size: 1.9rem; font-weight: 700; letter-spacing: -0.01em; margin-bottom: 3px; }
.home-bio .subtitle { font-size: 0.85rem; color: var(--gray-mid); margin-bottom: 6px; }
.fields { font-size: 0.8rem; color: var(--gray-mid); margin-bottom: 16px; letter-spacing: 0.01em; }
.home-bio p { font-size: 0.94rem; line-height: 1.78; color: var(--gray-dark); }
.home-bio p + p { margin-top: 13px; }
.contact-links { margin-top: 20px; display: flex; gap: 14px; flex-wrap: wrap; align-items: center; }
.contact-links a { font-size: 0.82rem; font-weight: 500; color: var(--gray-dark); }
.contact-links a:hover { color: var(--link); text-decoration: none; }
.contact-links .sep { color: var(--border); }

.news-section { margin-top: 44px; }
.news-item { display: flex; gap: 18px; padding: 10px 0; border-bottom: 1px solid var(--border); }
.news-item:last-child { border-bottom: none; }
.news-date { flex-shrink: 0; min-width: 82px; color: var(--orange); font-size: 0.8rem; font-weight: 600; padding-top: 2px; }
.news-item p { font-size: 0.875rem; color: var(--gray-dark); line-height: 1.55; }

.paper-links { display: flex; gap: 7px; flex-wrap: wrap; margin-bottom: 10px; }
.paper-chip {
  display: inline-block; padding: 2px 9px;
  font-size: 0.72rem; font-weight: 600; letter-spacing: 0.04em; text-transform: uppercase;
  border: 1px solid var(--border); border-radius: 3px;
  color: var(--gray-dark); background: var(--gray-light);
  transition: border-color 0.15s, color 0.15s;
}
.paper-chip:hover { border-color: var(--link); color: var(--link); text-decoration: none; }

.research-section { margin-bottom: 48px; }
.section-head {
  font-size: 0.72rem; font-weight: 700; text-transform: uppercase; letter-spacing: 0.1em;
  color: var(--orange); margin-bottom: 22px; padding-bottom: 7px; border-bottom: 1px solid var(--border);
}
.paper { margin-bottom: 28px; padding-bottom: 28px; border-bottom: 1px solid var(--border); }
.paper:last-child { border-bottom: none; }
.paper-title { font-size: 0.94rem; font-weight: 600; margin-bottom: 4px; line-height: 1.42; }
.paper-authors { font-size: 0.82rem; color: var(--gray-mid); margin-bottom: 5px; }
.paper-meta { font-size: 0.8rem; color: var(--gray-mid); margin-bottom: 10px; font-style: italic; }
.abstract-toggle {
  background: none; border: none; cursor: pointer; padding: 0;
  font-size: 0.72rem; font-weight: 700; color: var(--gray-mid);
  letter-spacing: 0.06em; text-transform: uppercase;
  display: inline-flex; align-items: center; gap: 5px;
}
.abstract-toggle:hover { color: var(--link); }
.abstract-toggle .arrow { font-size: 0.6rem; display: inline-block; transition: transform 0.2s; }
.abstract-toggle.open .arrow { transform: rotate(90deg); }
.abstract-body {
  display: none; margin-top: 11px; padding: 14px 16px;
  background: var(--gray-light); border-left: 3px solid var(--orange);
  border-radius: 0 4px 4px 0; font-size: 0.885rem; color: var(--gray-dark); line-height: 1.72;
}
.abstract-body.open { display: block; }

.cv-intro { font-size: 0.94rem; color: var(--gray-dark); margin-bottom: 24px; line-height: 1.7; }
.btn {
  display: inline-block; padding: 11px 26px;
  background: var(--orange); color: #fff !important;
  font-size: 0.875rem; font-weight: 600; border-radius: 4px;
  letter-spacing: 0.02em; transition: background 0.15s;
}
.btn:hover { background: #c45f00; text-decoration: none; }

.gallery-intro { font-size: 0.94rem; color: var(--gray-dark); margin-bottom: 28px; line-height: 1.7; }
.gallery-grid {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  grid-auto-rows: 320px;
  gap: 10px;
}
.gallery-item { overflow: hidden; border-radius: 4px; background: var(--gray-light); }
.gallery-item.wide { grid-column: span 2; }
.gallery-item img { width: 100%; height: 100%; object-fit: cover; display: block; transition: transform 0.4s ease; }
.gallery-item:hover img { transform: scale(1.04); }

footer { border-top: 1px solid var(--border); padding: 18px 24px; text-align: center; font-size: 0.77rem; color: var(--gray-mid); }

#lightbox {
  display: none; position: fixed; inset: 0; z-index: 200;
  background: rgba(0,0,0,0.92); cursor: zoom-out;
  align-items: center; justify-content: center;
}
#lightbox.open { display: flex; }
#lightbox img { max-width: 92vw; max-height: 92vh; object-fit: contain; border-radius: 3px; }
#lightbox-close {
  position: absolute; top: 18px; right: 22px;
  background: none; border: none; color: #fff; font-size: 2rem; cursor: pointer; line-height: 1;
}

.nav-toggle {
  display: none; background: none; border: none;
  font-size: 1.4rem; cursor: pointer; padding: 6px; color: var(--black); line-height: 1;
}

@media (max-width: 768px) {
  .nav-toggle { display: block; }
  nav { display: none; flex-direction: column; width: 100%; padding-bottom: 10px; }
  nav.open { display: flex; }
  nav a { padding: 9px 0; border-bottom: none; font-size: 0.9rem; }
  .home-hero { flex-direction: column; align-items: center; text-align: center; }
  .home-hero img { width: 140px; height: 140px; }
  .contact-links { justify-content: center; }
  .gallery-grid { grid-template-columns: 1fr; grid-auto-rows: 240px; }
}