.site-header {
  position: fixed;
  inset: 0 0 auto;
  z-index: 100;
  height: var(--header-height);
  background: var(--header-bg);
  border-bottom: 1px solid var(--line);
  backdrop-filter: blur(10px);
  transition: background 180ms ease, border-color 180ms ease;
}

.site-header.is-scrolled {
  background: var(--header-bg-scrolled);
  border-color: var(--line-strong);
}

.nav-wrap {
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: 100%;
}

.brand {
  display: inline-flex;
  align-items: center;
  gap: 10px;
}

.brand-logo {
  display: block;
  width: 28px;
  height: 28px;
  flex: 0 0 auto;
}

.brand-name {
  font-weight: 700;
  letter-spacing: -0.01em;
}

.site-nav {
  display: flex;
  align-items: center;
  gap: 22px;
}

.nav-link {
  padding: 6px 1px;
  color: var(--text-soft);
  border-bottom: 1px solid transparent;
  transition: color 160ms ease, border-color 160ms ease;
}

.nav-link:hover,
.nav-link:focus-visible,
.nav-link.is-active {
  color: var(--text);
  border-color: var(--text);
}

.nav-toggle {
  display: none;
  width: 40px;
  height: 40px;
  padding: 0;
  color: var(--text);
  background: transparent;
  border: 1px solid var(--line);
  border-radius: var(--radius-sm);
}

.nav-toggle-lines {
  position: relative;
  display: block;
  width: 18px;
  height: 12px;
  margin: auto;
}

.nav-toggle-lines::before,
.nav-toggle-lines::after,
.nav-toggle-lines span {
  position: absolute;
  left: 0;
  width: 100%;
  height: 2px;
  content: "";
  background: currentColor;
  border-radius: 999px;
  transition: transform 160ms ease, opacity 160ms ease;
}

.nav-toggle-lines::before {
  top: 0;
}

.nav-toggle-lines span {
  top: 5px;
}

.nav-toggle-lines::after {
  bottom: 0;
}

.nav-toggle[aria-expanded="true"] .nav-toggle-lines::before {
  transform: translateY(5px) rotate(45deg);
}

.nav-toggle[aria-expanded="true"] .nav-toggle-lines span {
  opacity: 0;
}

.nav-toggle[aria-expanded="true"] .nav-toggle-lines::after {
  transform: translateY(-5px) rotate(-45deg);
}

.link-arrow {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  color: var(--text);
  font-weight: 600;
  border-bottom: 1px solid var(--line-strong);
  transition: color 160ms ease, border-color 160ms ease;
}

.link-arrow::after {
  content: "\2192";
  transition: transform 160ms ease;
}

.link-arrow:hover,
.link-arrow:focus-visible {
  color: var(--accent);
  border-color: var(--accent);
}

.link-arrow:hover::after {
  transform: translateX(3px);
}

.about-points {
  display: grid;
  gap: 10px;
  padding: 0;
  margin: 20px 0 0;
  list-style: none;
}

.about-points li {
  position: relative;
  padding-left: 18px;
  color: var(--text-soft);
}

.about-points li::before {
  position: absolute;
  top: 0.72em;
  left: 0;
  width: 6px;
  height: 6px;
  content: "";
  background: var(--accent);
  border-radius: 50%;
}

.stat-list {
  display: flex;
  flex-wrap: wrap;
  gap: 24px 36px;
  padding: 0;
  margin: 0;
  list-style: none;
}

.stat {
  display: flex;
  flex-direction: column;
  gap: 4px;
}

.stat-value {
  font-family: var(--font-mono);
  font-size: 1.4rem;
  font-weight: 700;
}

.stat-label {
  color: var(--text-soft);
  font-size: 0.92rem;
}

.pair-list {
  display: grid;
  gap: 24px;
}

.pair-list.two-col {
  grid-template-columns: repeat(2, minmax(0, 1fr));
  column-gap: 40px;
}

.pair-item {
  padding-top: 16px;
  border-top: 1px solid var(--line);
}

.pair-title {
  margin: 0 0 8px;
  font-size: 1.05rem;
}

.pair-copy {
  margin: 0;
  color: var(--text-soft);
}

.skills-list {
  display: grid;
  gap: 4px;
}

.skills-group {
  display: grid;
  grid-template-columns: 200px minmax(0, 1fr);
  gap: 16px;
  padding: 14px 0;
  border-top: 1px solid var(--line);
  align-items: baseline;
}

.skills-group-title {
  margin: 0;
  font-size: 0.95rem;
  font-weight: 600;
}

.skills-group-items {
  margin: 0;
  color: var(--text-soft);
  font-family: var(--font-mono);
  font-size: 0.88rem;
}

.notes-group {
  margin-bottom: 36px;
}

.notes-group:last-child {
  margin-bottom: 0;
}

.notes-group-title {
  margin: 0 0 4px;
  font-size: 1.1rem;
}

.notes-empty {
  margin: 0;
  padding: 18px 0;
  color: var(--muted);
  font-family: var(--font-mono);
  font-size: 0.86rem;
  border-top: 1px solid var(--line);
}

.archive-list {
  border-top: 1px solid var(--line);
}

.archive-row {
  display: grid;
  grid-template-columns: 70px minmax(0, 1fr);
  gap: 16px;
  padding: 16px 0;
  border-bottom: 1px solid var(--line);
}

.archive-year {
  padding-top: 2px;
  color: var(--muted);
  font-family: var(--font-mono);
  font-size: 0.8rem;
}

.archive-title {
  margin: 0 0 4px;
  font-size: 1rem;
  font-weight: 600;
}

.archive-summary {
  margin: 0;
  color: var(--text-soft);
  font-size: 0.92rem;
}

.archive-row .entry-tags {
  margin-top: 8px;
  font-size: 0.78rem;
}

.prose {
  max-width: 680px;
}

.prose-copy {
  margin: 0 0 16px;
  color: var(--text-soft);
}

.prose-intro {
  max-width: 680px;
  margin-bottom: 28px;
}

.entry-list {
  border-top: 1px solid var(--line);
}

.entry {
  display: grid;
  grid-template-columns: 150px minmax(0, 1fr);
  gap: 24px;
  padding: 28px 0;
  border-bottom: 1px solid var(--line);
}

.entry-meta {
  display: flex;
  flex-direction: column;
  gap: 6px;
  padding-top: 3px;
}

.entry-category {
  color: var(--accent);
  font-family: var(--font-mono);
  font-size: 0.82rem;
}

.entry-status,
.entry-date {
  color: var(--muted);
  font-family: var(--font-mono);
  font-size: 0.78rem;
}

.entry-title {
  margin: 0;
  font-size: 1.18rem;
  line-height: 1.32;
}

.entry-why {
  margin: 12px 0 0;
  color: var(--text-soft);
}

.entry-why span {
  display: block;
  margin-bottom: 4px;
  color: var(--accent);
  font-family: var(--font-mono);
  font-size: 0.78rem;
}

.entry-summary {
  margin: 12px 0 0;
  color: var(--text-soft);
}

.entry-tags {
  margin: 14px 0 0;
  color: var(--muted);
  font-family: var(--font-mono);
  font-size: 0.82rem;
}

.timeline {
  display: flex;
  flex-direction: column;
  gap: 30px;
  padding: 4px 0 4px 22px;
  margin: 0;
  list-style: none;
  border-left: 1px solid var(--line);
}

.timeline-item {
  position: relative;
}

.timeline-item::before {
  position: absolute;
  top: 6px;
  left: -27px;
  width: 8px;
  height: 8px;
  content: "";
  background: var(--accent);
  border-radius: 50%;
}

.timeline-period {
  margin-bottom: 6px;
  color: var(--accent);
  font-family: var(--font-mono);
  font-size: 0.85rem;
}

.timeline-title {
  margin: 0;
  font-size: 1.05rem;
}

.timeline-org {
  margin: 4px 0 0;
  color: var(--muted);
}

.timeline-copy {
  margin: 10px 0 0;
  color: var(--text-soft);
}

.site-footer {
  padding: 32px 0;
  color: var(--muted);
  background: var(--bg-elevated);
  border-top: 1px solid var(--line);
}

.footer-contact {
  display: flex;
  flex-wrap: wrap;
  gap: 8px 24px;
  padding-bottom: 20px;
  margin-bottom: 20px;
  border-bottom: 1px solid var(--line);
}

.footer-contact-link {
  color: var(--text-soft);
  transition: color 160ms ease;
}

.footer-contact-link span {
  margin-right: 6px;
  color: var(--muted);
  font-family: var(--font-mono);
  font-size: 0.78rem;
}

.footer-contact-link:hover {
  color: var(--accent);
}

.footer-inner {
  display: flex;
  flex-wrap: wrap;
  justify-content: space-between;
  gap: 12px;
  font-size: 0.9rem;
}

.footer-links {
  display: flex;
  flex-wrap: wrap;
  gap: 14px;
}

.footer-links a:hover {
  color: var(--text);
}

[data-animate] {
  opacity: 0;
  transform: translateY(10px);
}

[data-animate].is-visible {
  opacity: 1;
  transform: translateY(0);
  transition: opacity 420ms ease, transform 420ms ease;
}

@media (max-width: 900px) {
  .nav-toggle {
    display: block;
  }

  .site-nav {
    position: fixed;
    top: 68px;
    right: 12px;
    left: 12px;
    display: grid;
    gap: 4px;
    padding: 10px;
    visibility: hidden;
    background: var(--bg-elevated);
    border: 1px solid var(--line);
    border-radius: var(--radius);
    opacity: 0;
    box-shadow: var(--shadow);
    transform: translateY(-10px);
    transition: opacity 160ms ease, transform 160ms ease, visibility 160ms ease;
  }

  .site-nav.is-open {
    visibility: visible;
    opacity: 1;
    transform: translateY(0);
  }

  .nav-link {
    display: block;
    padding: 10px 4px;
  }

  .entry {
    grid-template-columns: 1fr;
    gap: 8px;
  }

  .entry-meta {
    flex-direction: row;
    gap: 12px;
  }

  .footer-inner {
    flex-direction: column;
  }

  .pair-list.two-col {
    grid-template-columns: 1fr;
  }

  .skills-group {
    grid-template-columns: 1fr;
    gap: 6px;
  }

  .archive-row {
    grid-template-columns: 1fr;
    gap: 4px;
  }
}

/* Selective justification for prose-length Chinese explanatory paragraphs.
   Only enabled once the column is wide enough to avoid ugly gaps; short
   labels, metadata, headings, links and English copy stay left-aligned. */
@media (min-width: 621px) {
  .section-copy,
  .page-copy,
  .pair-copy,
  .entry-why,
  .entry-summary,
  .timeline-copy,
  .archive-summary,
  .prose-copy {
    text-align: justify;
    text-justify: inter-character;
    text-align-last: left;
  }
}