/* Custom Properties */
:root {
  --color-bg: #F7F8FA;
  --color-text: #1F2933;
  --color-muted: #525E6A;
  --color-link: #2F5DA8;
  --color-link-hover: #1E4A8A;
  --color-link-visited: #4A5568;
  --color-border: #E5E7EB;
  --color-border-hover: #D1D5DB;
  --color-surface: #F0F2F5;
  --color-badge-bg: #D1FAE5;
  --color-badge: #065F46;
  --font-sans: 'IBM Plex Sans', -apple-system, BlinkMacSystemFont, sans-serif;
  --font-serif: 'IBM Plex Serif', Georgia, serif;
  --font-mono: 'IBM Plex Mono', monospace;
}

/* Reset & Base */
*, *::before, *::after { box-sizing: border-box; }
* { margin: 0; padding: 0; }
html { font-size: 100%; -webkit-text-size-adjust: 100%; }

/* Skip Link */
.skip-link {
  position: absolute;
  top: -100%;
  left: 1rem;
  padding: 0.5rem 1rem;
  background: var(--color-link);
  color: white;
  border-radius: 0.25rem;
  z-index: 100;
}
.skip-link:focus {
  top: 1rem;
  color: white;
}

body {
  background-color: var(--color-bg);
  color: var(--color-text);
  font-family: var(--font-sans);
  font-size: 1rem;
  font-weight: 400;
  line-height: 1.6;
  min-height: 100vh;
  display: flex;
  flex-direction: column;
}

/* Typography */
h1, h2, h3, h4, h5, h6 {
  font-family: var(--font-serif);
  font-weight: 700;
  line-height: 1.3;
  color: var(--color-text);
}

h1 { font-size: 2.5rem; margin-bottom: 1.5rem; }
h2 { font-size: 1.75rem; margin-top: 2rem; margin-bottom: 1rem; }
h3 { font-size: 1.25rem; margin-top: 1.5rem; margin-bottom: 0.75rem; }
p { margin-bottom: 1rem; }
small, .small { font-size: 0.875rem; }

/* Links */
a { color: var(--color-link); text-decoration: none; }
a:hover { color: var(--color-link-hover); text-decoration: underline; }
a:visited { color: var(--color-link-visited); }

/* Layout */
.page-container { max-width: 70rem; margin: 0 auto; padding: 0 1.5rem; width: 100%; }
.content { max-width: 65ch; margin: 0 auto; padding: 2rem 0; }
main { flex: 1; }

/* Navigation */
.nav { padding: 1.375rem 0; border-bottom: 1px solid var(--color-border); }
.nav-inner { display: flex; flex-wrap: wrap; align-items: baseline; gap: 1.5rem; }
.nav-name {
  font-family: var(--font-serif);
  font-size: 1.375rem;
  font-weight: 700;
  color: var(--color-text);
  text-decoration: none;
  margin-right: auto;
}
.nav-name:hover { color: var(--color-text); text-decoration: none; }
.nav-links { display: flex; flex-wrap: wrap; gap: 1.5rem; list-style: none; }
.nav-links a { color: var(--color-muted); font-size: 1rem; font-weight: 500; text-decoration: none; }
.nav-links a:hover { color: var(--color-link); text-decoration: underline; }
.nav-links a.active { color: var(--color-link); }

/* Footer */
.footer { padding: 2rem 0; border-top: 1px solid var(--color-border); margin-top: auto; }
.footer-inner { color: var(--color-muted); font-size: 0.875rem; text-align: center; }

/* Home Page */
.home-intro { display: flex; flex-wrap: wrap; gap: 2rem; align-items: flex-start; }
.home-text { flex: 1; min-width: 280px; }
.portrait-column { flex-shrink: 0; text-align: center; }
.portrait { width: 16rem; height: 16rem; background-color: var(--color-border); }
.portrait img { width: 100%; height: 100%; object-fit: cover; }
.social-links { margin-top: 0.5rem; font-size: 0.875rem; }

/* Section Headers */
.section-header { margin-bottom: 2rem; }

/* Badges */
.status-badge {
  display: inline-block;
  font-size: 0.6875rem;
  font-weight: 500;
  padding: 0.125rem 0.5rem;
  border-radius: 0.25rem;
  background: var(--color-badge-bg);
  color: var(--color-badge);
  text-transform: uppercase;
  vertical-align: 0.125rem;
  text-indent: 0;
}

/* Year Navigation */
.year-nav { margin-bottom: 1.5rem; font-size: 0.875rem; color: var(--color-muted); }

/* Year Groups */
.year-group { margin-bottom: 2rem; }
.year-group h2 { font-size: 1.25rem; margin-bottom: 1rem; padding-bottom: 0.25rem; border-bottom: 1px solid var(--color-border); }

/* Bib Entries */
.bib-entry { padding: 1rem 0; padding-left: 2rem; text-indent: -2rem; border-bottom: 1px solid var(--color-border); }
.bib-entry .title { font-weight: 500; color: var(--color-link); text-decoration: none; }
.bib-entry .title:hover { text-decoration: underline; color: var(--color-link-hover); }
.bib-entry .venue { font-style: italic; }
.bib-entry .year { color: var(--color-muted); }
.links { display: block; margin-top: 0.25rem; font-size: 0.875rem; }
.bib-entry .links { padding-left: 2rem; }
.selected-publications .bib-entry .authors em { font-style: normal; }

/* News */
.news-list { list-style: none; padding: 0; margin: 0; }
.news-list li { display: grid; grid-template-columns: 6.5rem 1fr; gap: 0.5rem; padding: 0.5rem 0; border-bottom: 1px solid var(--color-border); }
.news-date { color: var(--color-muted); font-variant-numeric: tabular-nums; }

/* Detail Pages */
.detail-meta { color: var(--color-muted); margin-bottom: 1.5rem; }
.detail-meta p { margin-bottom: 0.25rem; }

.action-links { display: flex; flex-wrap: wrap; gap: 1rem; margin: 1.5rem 0; }
.action-links a {
  padding: 0.5rem 1rem;
  background-color: var(--color-link);
  color: white;
  border-radius: 0.25rem;
  font-size: 0.875rem;
  font-weight: 500;
}
.action-links a:hover { background-color: var(--color-link-hover); text-decoration: none; color: white; }
.action-links a:visited { color: white; }

/* BibTeX Block */
.bibtex-container { position: relative; margin: 1.5rem 0; }
.bibtex-block {
  background-color: var(--color-surface);
  padding: 1rem;
  border-radius: 0.25rem;
  overflow-x: auto;
  font-family: var(--font-mono);
  font-size: 0.875rem;
  line-height: 1.5;
}
.bibtex-copy {
  position: absolute;
  top: 0.5rem;
  right: 0.5rem;
  padding: 0.25rem 0.75rem;
  background-color: var(--color-border);
  border: none;
  border-radius: 0.25rem;
  font-size: 0.75rem;
  cursor: pointer;
  color: var(--color-muted);
}
.bibtex-copy:hover { background-color: var(--color-border-hover); }

/* Projects */
.project-card { margin-bottom: 2rem; padding-bottom: 1.5rem; border-bottom: 1px solid var(--color-border); }
.project-card:last-child { border-bottom: none; }
.project-card h3 { margin-top: 0; }
.project-meta { font-size: 0.875rem; color: var(--color-muted); margin-bottom: 0.5rem; }

/* Contact */
.contact-info { margin-bottom: 2rem; }
.contact-info dt { font-weight: 500; color: var(--color-muted); margin-top: 1rem; }
.contact-info dd { margin-left: 0; }

/* 404 */
.error-page { text-align: center; padding: 4rem 0; }
.error-page h1 { font-size: 4rem; margin-bottom: 1rem; }

/* Responsive */
@media (max-width: 768px) {
  h1 { font-size: 2rem; }
  h2 { font-size: 1.5rem; }
  .content { max-width: 55ch; }
  .home-intro { flex-direction: column-reverse; }
  .portrait-column { width: 100%; }
  .portrait { max-width: 14rem; height: auto; aspect-ratio: 1; margin: 0 auto; }
  .nav-inner, .nav-links { gap: 1rem; }
}

@media (max-width: 480px) {
  .content { max-width: 40ch; }
  .page-container { padding: 0 1rem; }
}

/* Print */
@media print {
  body { background: white; color: black; font-size: 12pt; }
  .nav, .footer, .year-nav, .bibtex-copy, .action-links { display: none; }
  .page-container, .content { max-width: 100%; padding: 0; margin: 0; }
  a { color: black; text-decoration: underline; }
  a[href^="http"]::after { content: " (" attr(href) ")"; font-size: 0.8em; }
  a[href^="mailto"]::after { content: " (" attr(href) ")"; font-size: 0.8em; }
  .portrait { width: 10rem; height: 10rem; }
  .bibtex-block { background: none; border: 1px solid black; }
  h1, h2, h3 { page-break-after: avoid; }
  .bib-entry, .project-card { page-break-inside: avoid; }
}