html, body {
  height: 100%;
  margin: 0;
  padding: 0;
}

a {
  color: #008000;
}

body {
  display: flex;
  flex-direction: column;
  margin: 0;
  font-family: system-ui, sans-serif;
  background-color: #fff;
  color: #111;
}

header {
  border-bottom: 1px solid #ccc;
  padding: 0.75rem 0;
  position: sticky;
  top: 0;
  background-color: rgba(255, 255, 255, 0.95);
  backdrop-filter: blur(5px);
  z-index: 1000;
}

.header-inner {
  max-width: 800px;
  margin: 0 auto;
  padding: 0 1.5rem;
  display: flex;
  justify-content: space-between;
  align-items: center;
}

.site-title a {
  font-size: 1.5rem;
  font-weight: 600;
  line-height: 1;
  color: #111;
  text-decoration: none;
}

.nav-links {
  display: flex;
  gap: 1.5rem;
}

.nav-links a {
  text-decoration: none;
  color: #555;
  font-weight: 500;
}

.nav-links a:hover {
  text-decoration: underline;
}

.site-title a.active,
.nav-links a.active {
  color: #008000;
}

.container {
  flex: 1;
  max-width: 800px;
  margin: 0 auto;
  padding: 2rem 1.5rem;
  width: 100%;
  box-sizing: border-box;
}

.divider {
  border: 0;
  margin: 1rem;
}

h2 {
  font-size: 1.25rem;
  font-weight: 600;
  color: #008000;
  margin-bottom: 1rem;
  border-left: 3px solid #008000;
  padding-left: 10px;
}

ul {
  list-style: none;
  padding: 0;
  margin: 0;
}

li {
  margin-bottom: 0.5rem;
}

/* Home page: bio */
.bio-section {
  display: flex;
  align-items: center;
  gap: 2rem;
}

.bio-text {
  text-align: justify;
}

.profile-photo {
  display: block;
  width: 250px;
  height: 250px;
  object-fit: cover;
}

/* Papers (home + CV) */
.paper-item {
  margin-bottom: 2rem;
}

.paper-title {
  font-size: 1rem;
  font-weight: 600;
}

.paper-title a {
  text-decoration: none;
  color: #008000;
}

.paper-title a:hover {
  text-decoration: underline;
}

.paper-meta {
  font-size: 0.9rem;
  color: #555;
  font-style: italic;
  margin-bottom: 0.5rem;
}

details.abstract-toggle {
  margin-bottom: 0.75rem;
}

details.abstract-toggle summary {
  font-size: 0.85rem;
  color: #999;
  cursor: pointer;
  list-style: none;
  display: inline-block;
  user-select: none;
}

details.abstract-toggle summary::-webkit-details-marker { display: none; }
details.abstract-toggle summary::after { content: ' ↓'; }
details.abstract-toggle[open] summary::after { content: ' ↑'; }
details.abstract-toggle summary:hover { color: #008000; }

details.abstract-toggle .abstract-text {
  margin-top: 0.5rem;
  font-size: 0.9rem;
  color: #444;
  text-align: justify;
}

.coauthor-link {
  color: #555;
  border-bottom: 1px dotted #ccc;
}

.coauthor-link:hover {
  color: #008000;
  border-bottom: 1px solid #008000;
  text-decoration: none;
}

/* CV page */
.cv-header {
  display: flex;
  justify-content: space-between;
  align-items: flex-start;
  margin-bottom: 1rem;
  gap: 2rem;
}

.btn-download {
  display: inline-block;
  padding: 0.6rem 1.2rem;
  border: 1px solid #008000;
  border-radius: 4px;
  color: #008000;
  font-weight: 500;
  font-size: 0.9rem;
  white-space: nowrap;
}

.btn-download:hover {
  background-color: #008000;
  color: #fff;
  text-decoration: none;
}

.edu-item {
  display: flex;
  justify-content: space-between;
  align-items: baseline;
}

.edu-degree {
  font-weight: 500;
}

.edu-year {
  color: #999;
  font-size: 0.9rem;
  white-space: nowrap;
  margin-left: 1rem;
}

.research-list li {
  position: relative;
  padding-left: 1rem;
}

.research-list li::before {
  content: "•";
  color: #008000;
  position: absolute;
  left: 0;
  font-weight: bold;
}

/* Teaching page */
.course-list {
  list-style: none;
  padding: 0;
  margin: 0;
}

.course-item {
  display: flex;
  justify-content: space-between;
  align-items: baseline;
  padding: 0.5rem 0;
}

.course-item:last-child {
  border-bottom: none;
}

.course-title {
  font-weight: 500;
  flex: 1;
  margin-right: 1rem;
}

.course-details {
  text-align: right;
  font-size: 0.9rem;
  color: #999;
  white-space: nowrap;
}

.institution {
  font-size: 0.9rem;
  color: #999;
  margin-left: 0.5rem;
}

/* Footer */
.site-footer {
  background-color: #fafafa;
  font-size: 0.9rem;
  color: #555;
  padding: 0.5rem 0.5rem 0.5rem;
  border-top: 1px solid #eee;
}

.site-footer a {
  color: #008000;
  text-decoration: none;
}

.footer-inner {
  max-width: 800px;
  margin: 0 auto;
  display: flex;
  justify-content: space-between;
  align-items: center;
}

.footer-left, .footer-center, .footer-right {
  flex: 1;
}

.footer-left { text-align: left; }
.footer-center { text-align: center; }
.footer-right { text-align: right; }

.site-footer a:hover {
  text-decoration: underline;
}

.footer-right .icon-link {
  display: inline-flex;
  align-items: center;
  color: #555;
}

.footer-right .icon-link:hover {
  color: #008000;
}

.footer-right .icon-link svg {
  display: block;
  width: 18px;
  height: 18px;
  fill: currentColor;
}

@media (max-width: 600px) {
  .header-inner,
  .footer-inner {
    flex-direction: column;
    align-items: center;
    text-align: center;
  }

  .bio-section {
    display: flex;
    align-items: center;
    gap: 1rem;
  }

  .profile-photo {
    display: block;
    width: 150px;
    height: 150px;
    object-fit: cover;
  }

  .cv-header {
    flex-direction: column;
  }

  .footer-left, .footer-center, .footer-right {
    text-align: center;
    width: 100%;
  }
}