* {
  box-sizing: border-box;
  margin: 0;
  padding: 0;
}

html {
  overflow-y: scroll;
}

body {
  font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, 'Helvetica Neue', Arial, sans-serif;
  font-size: 16px;
  line-height: 1.65;
  color: #1a1a1a;
  background: #fff;
}

/* ── Header ── */

header {
  background: #f2f2f2;
  padding: 20px 0;
}

.header-inner {
  max-width: 1050px;
  margin: 0 auto;
  padding: 0 24px;
  display: flex;
  align-items: center;
}

.header-identity {
  flex-shrink: 0;
}

.container {
  max-width: 760px;
  margin: 0 auto;
  padding: 36px 24px 48px;
}

.site-name {
  font-size: 2.3em;
  font-weight: 700;
  letter-spacing: -0.3px;
  color: #1a1a1a;
  line-height: 1;
  margin-bottom: 8px;
}

.site-position {
  font-size: 1em;
  color: #666;
  line-height: 1;
  margin-bottom: 8px;
}

nav {
  flex: 1;
  display: flex;
  justify-content: center;
  align-items: center;
  gap: 24px;
}

nav a {
  color: #1a1a1a;
  text-decoration: none;
  font-size: 1.15em;
  white-space: nowrap;
}

nav a:hover {
  color: #cc5500;
}

nav a.active {
  color: #cc5500;
  text-decoration: underline;
}

/* ── Dividers ── */

hr {
  border: none;
  border-top: 1px solid #ddd;
  margin: 28px 0;
}

/* ── About page ── */

.about-grid {
  display: flex;
  gap: 36px;
  align-items: flex-start;
}

.about-photo img {
  width: 165px;
  display: block;
}

.about-bio p {
  margin-bottom: 14px;
  color: #1a1a1a;
}

.about-bio p:last-child {
  margin-bottom: 0;
}

/* ── Research page ── */

.section-heading {
  font-size: 1em;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 0.1em;
  color: #cc5500;
  margin-top: 36px;
  margin-bottom: 4px;
}

.section-heading:first-child {
  margin-top: 0;
}

.paper-card {
  padding: 20px 0;
  border-bottom: 1px solid #ddd;
}

.paper-card:first-of-type {
  border-top: 1px solid #ddd;
}

.paper-headline {
  margin-bottom: 4px;
}

.paper-title {
  font-weight: 600;
  color: #1a1a1a;
}

.paper-authors {
  font-size: 0.88em;
  color: #1a1a1a;
  font-weight: 400;
}

.paper-authors a {
  color: inherit;
  text-decoration: none;
  border-bottom: 1px solid #bbb;
}

.paper-authors a:hover {
  color: #cc5500;
  border-bottom-color: #cc5500;
}

.paper-venue {
  font-size: 0.88em;
  color: #1a1a1a;
  font-weight: 400;
  margin-bottom: 10px;
}

.paper-abstract {
  display: none;
  font-size: 0.88em;
  line-height: 1.75;
  color: #444;
  margin-bottom: 10px;
}

.paper-abstract.open {
  display: block;
}

.paper-links {
  display: flex;
  gap: 6px;
  flex-wrap: wrap;
  align-items: center;
  margin-top: 10px;
}

.pill-btn {
  display: inline-block;
  -webkit-appearance: none;
  appearance: none;
  font-size: 0.7em;
  font-family: inherit;
  font-weight: 400;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  padding: 5px 16px;
  border-radius: 100px;
  border: 1px solid #bbb;
  background: none;
  color: #666;
  cursor: pointer;
  text-decoration: none;
  transition: border-color 0.18s, color 0.18s, background 0.18s;
}

.pill-btn:hover {
  border-color: #555;
  color: #333;
  background: #f2f2f2;
}

/* ── Contact page ── */

.contact-block {
  margin-bottom: 20px;
}

.contact-block:last-child {
  margin-bottom: 0;
}

.contact-label {
  font-size: 0.78em;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 0.1em;
  color: #cc5500;
  margin-bottom: 6px;
}

.contact-block p {
  color: #1a1a1a;
  margin-bottom: 2px;
}

.contact-block a {
  color: #1a1a1a;
  text-decoration: none;
  border-bottom: 1px solid #ccc;
}

.contact-block a:hover {
  color: #cc5500;
  border-bottom-color: #cc5500;
}

/* ── Footer ── */

footer {
  background: #f2f2f2;
  padding: 10px 0;
}

.footer-inner {
  max-width: 1050px;
  margin: 0 auto;
  padding: 0 24px;
}

footer a {
  font-size: 0.9em;
  color: #888;
  text-decoration: none;
}

footer a:hover {
  color: #cc5500;
}

/* ── Responsive ── */

@media (max-width: 680px) {
  .header-inner {
    padding: 0 16px;
    flex-direction: column;
    align-items: flex-start;
    gap: 12px;
  }

  nav {
    flex: none;
    justify-content: flex-start;
    flex-wrap: wrap;
    gap: 10px 20px;
  }

  .about-grid {
    flex-direction: column;
  }

  .about-photo img {
    width: 140px;
  }
}