/* =========================================================
   Site shell
   ========================================================= */
.site-shell {
  padding: 0 0 var(--space-6);
}

/* =========================================================
   Masthead (shared by every page)
   ========================================================= */
.site-header {
  position: sticky;
  top: 0;
  z-index: 100;
  background: var(--color-surface);
  backdrop-filter: blur(16px);
  -webkit-backdrop-filter: blur(16px);
  border-bottom: 1px solid var(--color-rule);
  padding: 1rem 0;
  margin-bottom: var(--space-4);
}

.site-header .site-wrap {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: var(--space-3) var(--space-4);
  flex-wrap: wrap;
}

.site-header__mark {
  display: inline-flex;
  align-items: baseline;
  gap: 0.5rem;
  font-family: "Outfit", sans-serif;
  font-size: 1.25rem;
  font-weight: 700;
  color: var(--color-text);
  text-decoration: none;
  letter-spacing: -0.01em;
  padding: 0.2rem 0;
}

.site-header__mark:hover {
  color: var(--color-accent);
}

.site-header__mark span {
  color: var(--color-text-soft);
  font-weight: 500;
  font-size: 0.9em;
}

/* =========================================================
   Navigation
   ========================================================= */
.site-nav {
  margin: 0;
}

.site-nav__list {
  list-style: none;
  margin: 0;
  padding: 0;
  display: flex;
  flex-wrap: wrap;
  gap: 0.25rem 1.5rem;
  align-items: center;
}

.site-nav__item {
  position: relative;
}

.site-nav__link,
.dropdown-toggle {
  display: inline-block;
  border: 0;
  background: transparent;
  padding: 0.5rem 0;
  font: inherit;
  font-size: 0.95rem;
  font-weight: 500;
  color: var(--color-text-muted);
  text-decoration: none;
  cursor: pointer;
  position: relative;
  transition: color var(--transition-fast);
}

.site-nav__link:hover,
.dropdown-toggle:hover {
  color: var(--color-accent);
}

.site-nav__link[aria-current="page"],
.site-nav__item.active > .site-nav__link {
  color: var(--color-text);
  font-weight: 600;
}

.site-nav__link::after,
.dropdown-toggle::after {
  content: "";
  position: absolute;
  left: 0;
  right: 0;
  bottom: -2px;
  height: 2px;
  background: var(--color-accent);
  border-radius: 2px;
  transform: scaleX(0);
  transition: transform var(--transition-normal);
  transform-origin: left;
}

.site-nav__link:hover::after,
.dropdown-toggle:hover::after {
  transform: scaleX(1);
}

.site-nav__link[aria-current="page"]::after,
.site-nav__item.active > .site-nav__link::after {
  transform: scaleX(1);
  background: var(--color-text);
}

.dropdown-toggle {
  display: inline-flex;
  align-items: center;
  gap: 0.4rem;
}

.dropdown-toggle::before {
  content: "";
  position: absolute;
  left: 0;
  right: 0;
  bottom: -2px;
  height: 2px;
  background: var(--color-accent);
  border-radius: 2px;
  transform: scaleX(0);
  transition: transform var(--transition-normal);
  transform-origin: left;
}
.dropdown-toggle::after {
  display: none;
}
.dropdown-toggle:hover::before {
  transform: scaleX(1);
}

.dropdown-toggle svg,
.dropdown-toggle::after {
  content: "";
  width: 0.4rem;
  height: 0.4rem;
  border-right: 2px solid currentColor;
  border-bottom: 2px solid currentColor;
  transform: rotate(45deg) translateY(-2px);
  opacity: 0.7;
}

.dropdown-menu {
  position: absolute;
  right: 0;
  top: calc(100% + 0.5rem);
  min-width: 200px;
  display: none;
  list-style: none;
  padding: 0.5rem;
  margin: 0;
  background: var(--color-surface-solid);
  border: 1px solid var(--color-rule);
  border-radius: var(--border-radius);
  box-shadow: var(--shadow-lg);
  z-index: 20;
  animation: fade-in-up 0.2s ease forwards;
}

@keyframes fade-in-up {
  from { opacity: 0; transform: translateY(10px); }
  to { opacity: 1; transform: translateY(0); }
}

.dropdown.open .dropdown-menu,
.dropdown:hover .dropdown-menu {
  display: block;
}

.dropdown-menu a {
  display: block;
  padding: 0.6rem 1rem;
  font-size: 0.95rem;
  text-decoration: none;
  color: var(--color-text);
  border-radius: var(--border-radius-sm);
  transition: all var(--transition-fast);
}

.dropdown-menu a:hover {
  background: var(--color-accent-soft);
  color: var(--color-accent-strong);
  transform: translateX(2px);
}

.dropdown-menu a[aria-current="page"] {
  color: var(--color-accent);
  font-weight: 600;
  background: var(--color-accent-soft);
}

/* =========================================================
   Home hero
   ========================================================= */
.site-hero {
  display: grid;
  grid-template-columns: minmax(0, 1fr) 300px;
  gap: var(--space-6);
  align-items: center;
  padding: var(--space-6) 0 var(--space-6);
  border-bottom: 1px solid var(--color-rule);
  position: relative;
}

.site-hero::before {
  content: '';
  position: absolute;
  top: 50%;
  left: 50%;
  width: 600px;
  height: 600px;
  background: radial-gradient(circle, var(--color-glow) 0%, transparent 70%);
  transform: translate(-50%, -50%);
  z-index: -1;
  pointer-events: none;
}

.site-hero__eyebrow {
  display: inline-block;
  margin: 0 0 var(--space-3);
  padding: 0.4rem 0.8rem;
  background: var(--color-accent-soft);
  color: var(--color-accent-strong);
  border-radius: var(--border-radius-full);
  text-transform: uppercase;
  letter-spacing: 0.1em;
  font-size: 0.75rem;
  font-weight: 700;
  font-family: "Outfit", sans-serif;
}

.site-hero h1 {
  margin: 0;
  font-size: clamp(2.5rem, 5vw, 4rem);
  font-weight: 800;
  letter-spacing: -0.03em;
  line-height: 1.1;
  background: linear-gradient(135deg, var(--color-text) 0%, var(--color-accent-strong) 100%);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}

.site-hero h1 .name-cn {
  font-weight: 600;
  margin-left: 0.25em;
}

.site-hero__affiliation,
.site-hero__affiliation-cn {
  margin: 0;
  color: var(--color-text-muted);
}

.site-hero__affiliation {
  margin-top: var(--space-3);
  font-size: 1.15rem;
  font-weight: 500;
}

.site-hero__affiliation-cn {
  margin-top: 0.25rem;
  font-size: 1rem;
  font-family: "Songti SC", "STSong", "SimSun", serif;
  letter-spacing: 0.05em;
  color: var(--color-text-soft);
}

.site-hero__statement {
  margin: var(--space-4) 0 0;
  max-width: 58ch;
  color: var(--color-text-muted);
  font-size: 1.1rem;
  line-height: 1.8;
}

.site-hero__orcid {
  display: inline-flex;
  align-items: center;
  gap: 0.5rem;
  margin-top: var(--space-4);
  padding: 0.5rem 1rem;
  background: var(--color-surface-solid);
  color: var(--color-text-muted);
  text-decoration: none;
  font-size: 0.95rem;
  font-weight: 600;
  border-radius: var(--border-radius-full);
  border: 1px solid var(--color-rule);
  box-shadow: var(--shadow-sm);
  transition: all var(--transition-fast);
}

.site-hero__orcid:hover {
  transform: translateY(-2px);
  box-shadow: var(--shadow-md);
  border-color: #a6ce39;
  color: var(--color-text);
}

.site-hero__orcid img {
  width: 26px;
  height: 26px;
  display: inline-block;
  flex-shrink: 0;
}

.site-hero__photo-wrap {
  justify-self: end;
  align-self: center;
}

.site-hero__photo {
  width: 280px;
  height: 280px;
  object-fit: cover;
  border-radius: var(--border-radius-lg);
  border: 4px solid var(--color-surface-solid);
  box-shadow: var(--shadow-lg), var(--shadow-glow);
  transition: transform var(--transition-normal);
}

.site-hero__photo:hover {
  transform: scale(1.02) rotate(-1deg);
}

/* =========================================================
   Page head (inner pages)
   ========================================================= */
.page-head {
  padding: var(--space-5) 0 var(--space-3);
  position: relative;
}

.page-head::after {
  content: '';
  position: absolute;
  bottom: 0;
  left: 0;
  width: 60px;
  height: 4px;
  background: var(--color-accent);
  border-radius: 2px;
}

.page-title {
  margin: 0 0 var(--space-2);
  font-family: "Outfit", serif;
  font-size: clamp(2rem, 4vw, 3rem);
  font-weight: 800;
  line-height: 1.15;
  letter-spacing: -0.02em;
}

.page-lead {
  margin: 0;
  max-width: 64ch;
  color: var(--color-text-muted);
  font-size: 1.1rem;
  line-height: 1.8;
}

/* =========================================================
   Main content layout
   ========================================================= */
.site-main {
  display: block;
  margin-top: var(--space-4);
}

.site-main > section {
  margin-top: var(--space-7);
  padding-top: 0;
  position: relative;
}

.site-main > section:first-child,
.site-main > .page-head + section {
  margin-top: var(--space-6);
}

.site-main h2 {
  margin: 0 0 var(--space-4);
  font-size: clamp(1.5rem, 2.5vw, 2rem);
  font-weight: 700;
}

.site-main h3 {
  margin: 0 0 0.75rem;
  font-size: 1.25rem;
  line-height: 1.4;
}

.site-main p {
  margin: 1rem 0;
}

.site-main ul,
.site-main ol {
  padding-left: 1.5rem;
}

.site-main li {
  margin: 0.5rem 0;
}

/* =========================================================
   Cards (Replacing legacy card classes)
   ========================================================= */
.page-card,
.mini-card {
  background: var(--color-surface-solid);
  border: 1px solid var(--color-rule);
  border-radius: var(--border-radius);
  padding: var(--space-4);
  box-shadow: var(--shadow-sm);
  transition: all var(--transition-normal);
}

.page-card:hover,
.mini-card:hover {
  box-shadow: var(--shadow-md);
  transform: translateY(-2px);
}

/* =========================================================
   Reference / publication list
   ========================================================= */
.ref-list {
  list-style: none;
  margin: 0;
  padding: 0;
  display: flex;
  flex-direction: column;
  gap: var(--space-4);
}

.ref-entry {
  padding: var(--space-4);
  background: var(--color-surface-solid);
  border: 1px solid var(--color-rule);
  border-radius: var(--border-radius);
  box-shadow: var(--shadow-sm);
  transition: all var(--transition-normal);
}

.ref-entry:hover {
  box-shadow: var(--shadow-md);
  border-color: var(--color-accent-soft);
  transform: translateY(-2px);
}

.ref-entry h3 {
  margin: 0 0 0.5rem;
  font-size: 1.15rem;
  line-height: 1.5;
  font-weight: 700;
  color: var(--color-text);
}

.ref-entry p {
  margin: 0.4rem 0;
  font-size: 1rem;
  line-height: 1.7;
  max-width: 80ch;
}

.ref-entry .ref-authors {
  color: var(--color-text-muted);
}
.ref-entry .ref-authors strong {
  color: var(--color-text);
}

.ref-entry .ref-venue {
  color: var(--color-accent);
  font-weight: 500;
}

.ref-entry .ref-tldr {
  margin-top: 1rem;
  padding: 1rem;
  background: var(--color-bg);
  border-radius: var(--border-radius-sm);
  color: var(--color-text-muted);
  font-size: 0.95rem;
}

.ref-entry .ref-tldr::before {
  content: "Abstract";
  display: block;
  font-weight: 700;
  color: var(--color-text);
  margin-bottom: 0.25rem;
}

.publication-links {
  margin-top: 1.25rem;
  display: flex;
  flex-wrap: wrap;
  gap: 0.75rem;
  font-family: "Inter", sans-serif;
}

.publication-links a,
.publication-links .btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  padding: 0.4rem 1rem;
  border: 1px solid var(--color-rule-strong);
  background: var(--color-surface-solid);
  color: var(--color-text);
  font-weight: 600;
  font-size: 0.9rem;
  text-decoration: none;
  border-radius: var(--border-radius-full);
  transition: all var(--transition-fast);
}

.publication-links a:hover,
.publication-links .btn:hover {
  background: var(--color-accent);
  color: white;
  border-color: var(--color-accent);
  transform: translateY(-1px);
  box-shadow: var(--shadow-sm);
}

/* =========================================================
   Buttons
   ========================================================= */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  padding: 0.5rem 1.25rem;
  border: 1px solid var(--color-rule-strong);
  background: var(--color-surface-solid);
  color: var(--color-text);
  font-weight: 600;
  font-size: 0.95rem;
  text-decoration: none;
  border-radius: var(--border-radius-full);
  transition: all var(--transition-fast);
  cursor: pointer;
}

.btn:hover {
  background: var(--color-accent);
  color: white;
  border-color: var(--color-accent);
  transform: translateY(-1px);
  box-shadow: var(--shadow-md);
}

.btn-primary {
  background: var(--color-accent);
  color: white;
  border-color: var(--color-accent);
}

.btn-primary:hover {
  background: var(--color-accent-strong);
  border-color: var(--color-accent-strong);
  transform: translateY(-2px);
  box-shadow: var(--shadow-md), var(--shadow-glow);
}

.btn-secondary {
  background: var(--color-accent-soft);
  color: var(--color-accent-strong);
  border: 0;
}

.btn-secondary:hover {
  background: var(--color-accent);
  color: white;
  transform: translateY(-2px);
  box-shadow: var(--shadow-md);
}

a.more-link {
  display: inline-flex;
  align-items: center;
  gap: 0.5rem;
  color: var(--color-accent);
  text-decoration: none;
  font-weight: 600;
  font-size: 0.95rem;
  padding: 0.5rem 0;
  border: none;
}
a.more-link:hover {
  color: var(--color-accent-strong);
  gap: 0.75rem; /* subtle arrow shift effect */
}


/* =========================================================
   Tags & Badges
   ========================================================= */
.tag {
  display: inline-block;
  margin: 0 0 0.5rem;
  padding: 0.25rem 0.75rem;
  background: var(--color-accent-soft);
  color: var(--color-accent-strong);
  text-transform: uppercase;
  letter-spacing: 0.1em;
  font-size: 0.75rem;
  font-weight: 700;
  border-radius: var(--border-radius-full);
  font-family: "Inter", sans-serif;
}

/* =========================================================
   Home: research highlights (3-column dynamic cards)
   ========================================================= */
.grid-3 {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: var(--space-4);
}

.grid-2 {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: var(--space-4);
}

.highlight {
  display: flex;
  flex-direction: column;
  background: var(--color-surface-solid);
  border: 1px solid var(--color-rule);
  border-radius: var(--border-radius-lg);
  padding: var(--space-4);
  box-shadow: var(--shadow-sm);
  transition: all var(--transition-normal);
  position: relative;
  overflow: hidden;
}

.highlight::before {
  content: '';
  position: absolute;
  top: 0; left: 0; right: 0;
  height: 4px;
  background: linear-gradient(90deg, var(--color-accent), #38bdf8);
  opacity: 0;
  transition: opacity var(--transition-normal);
}

.highlight:hover {
  box-shadow: var(--shadow-lg);
  transform: translateY(-5px);
  border-color: transparent;
}

.highlight:hover::before {
  opacity: 1;
}

.highlight h3 {
  margin: 0 0 0.75rem;
  font-size: 1.25rem;
}

.highlight p {
  margin: 0 0 1.5rem;
  font-size: 1rem;
  line-height: 1.7;
  color: var(--color-text-muted);
  flex-grow: 1;
}


/* =========================================================
   CV timeline
   ========================================================= */
.cv-group {
  margin: 0;
  position: relative;
  padding-left: 2rem;
}

.cv-group::before {
  content: '';
  position: absolute;
  top: 0;
  bottom: 0;
  left: 0.45rem;
  width: 2px;
  background: var(--color-rule);
}

.cv-entry {
  display: grid;
  grid-template-columns: 8rem minmax(0, 1fr);
  gap: var(--space-3) var(--space-4);
  padding: var(--space-4) 0;
  position: relative;
}

.cv-entry::before {
  content: '';
  position: absolute;
  top: 1.8rem;
  left: -1.8rem;
  width: 0.6rem;
  height: 0.6rem;
  background: var(--color-surface-solid);
  border: 2px solid var(--color-accent);
  border-radius: 50%;
  transition: all var(--transition-fast);
}

.cv-entry:hover::before {
  background: var(--color-accent);
  box-shadow: 0 0 0 4px var(--color-accent-soft);
}

.cv-entry:first-of-type {
  border-top: 0;
}

.cv-entry__year {
  color: var(--color-text-muted);
  font-family: "Outfit", serif;
  font-weight: 600;
  font-size: 1.1rem;
  padding-top: 0.2rem;
}

.cv-entry__body > :first-child {
  margin-top: 0;
}

.cv-entry__body h3 {
  margin: 0 0 0.4rem;
  font-size: 1.15rem;
}

.cv-entry__body p {
  margin: 0.3rem 0;
  color: var(--color-text-muted);
  font-size: 1rem;
}

.cv-entry__body .cv-note {
  color: var(--color-text-soft);
  font-size: 0.95rem;
  margin-top: 0.5rem;
  background: var(--color-bg);
  padding: 0.5rem 1rem;
  border-radius: var(--border-radius-sm);
  display: inline-block;
}

/* =========================================================
   Links page: definition-list groups
   ========================================================= */
.link-group {
  margin: 0 0 var(--space-5);
  background: var(--color-surface-solid);
  padding: var(--space-4);
  border-radius: var(--border-radius);
  border: 1px solid var(--color-rule);
  box-shadow: var(--shadow-sm);
}

.link-group dt {
  margin: var(--space-4) 0 1rem;
  color: var(--color-accent);
  text-transform: uppercase;
  letter-spacing: 0.1em;
  font-size: 0.85rem;
  font-weight: 700;
}

.link-group dt:first-child {
  margin-top: 0;
}

.link-group dd {
  margin: 0 0 0.75rem 0;
  font-size: 1.05rem;
  display: flex;
  align-items: center;
  gap: 0.5rem;
}

.link-group dd a {
  font-weight: 500;
  text-decoration: none;
}

.link-group dd .link-note {
  color: var(--color-text-soft);
  font-size: 0.9rem;
  margin-left: auto;
}

/* =========================================================
   Talks list (activities page)
   ========================================================= */
.talk-list {
  list-style: none;
  padding: 0;
  margin: 0;
  display: flex;
  flex-direction: column;
  gap: var(--space-3);
}

.talk {
  display: grid;
  grid-template-columns: 4.5rem minmax(0, 1fr);
  gap: 1rem var(--space-4);
  padding: var(--space-3);
  background: var(--color-surface-solid);
  border: 1px solid var(--color-rule);
  border-radius: var(--border-radius);
  transition: all var(--transition-fast);
}
.talk:hover {
  box-shadow: var(--shadow-md);
  border-color: var(--color-accent-soft);
  transform: translateX(4px);
}

.talk__year {
  color: var(--color-accent);
  font-family: "Outfit", serif;
  font-weight: 700;
  font-size: 1.1rem;
}

.talk__body {
  max-width: 72ch;
}

.talk__body p {
  margin: 0.2rem 0;
  font-size: 1rem;
  line-height: 1.6;
}

.talk__venue {
  color: var(--color-text-muted);
  font-size: 0.95rem;
  display: inline-flex;
  align-items: center;
  gap: 0.4rem;
}
.talk__venue::before {
  content: '📍';
  font-size: 0.8em;
}

.talk__title a {
  color: var(--color-text);
  font-weight: 600;
  text-decoration: none;
}

.talk__title a:hover {
  color: var(--color-accent);
}

.talk__kind {
  display: inline-block;
  padding: 0.15rem 0.6rem;
  background: var(--color-bg);
  color: var(--color-text-muted);
  font-size: 0.75rem;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 0.1em;
  border-radius: var(--border-radius-full);
  margin-right: 0.75rem;
}

/* =========================================================
   Contact block
   ========================================================= */
.contact-info {
  margin: 0;
  font-style: normal;
  font-size: 1.05rem;
  line-height: 2;
  background: var(--color-surface-solid);
  padding: var(--space-4);
  border-radius: var(--border-radius-lg);
  border: 1px solid var(--color-rule);
  box-shadow: var(--shadow-md);
}

.contact-info .contact-line {
  display: flex;
  margin: 0;
  border-bottom: 1px solid var(--color-rule);
  padding: 0.75rem 0;
}
.contact-info .contact-line:last-child {
  border-bottom: none;
}

.contact-info .contact-label {
  display: inline-block;
  min-width: 8rem;
  color: var(--color-text-muted);
  text-transform: uppercase;
  letter-spacing: 0.1em;
  font-size: 0.8rem;
  font-weight: 700;
  font-family: "Outfit", sans-serif;
}

/* =========================================================
   Footer
   ========================================================= */
.site-footer {
  margin-top: var(--space-7);
  padding: var(--space-5) 0 var(--space-4);
  border-top: 1px solid var(--color-rule);
  background: var(--color-surface-solid);
  color: var(--color-text-muted);
  text-align: center;
  font-size: 0.95rem;
}

.site-footer p {
  margin: 0.2rem 0;
  color: inherit;
  max-width: none;
}

.footer-meta {
  margin-top: var(--space-3);
  font-size: 0.85rem;
}

.time-zones {
  margin-top: 1rem;
  display: flex;
  flex-wrap: wrap;
  gap: 0.75rem 2rem;
  justify-content: center;
}

.time-zones span {
  white-space: nowrap;
  display: flex;
  flex-direction: column;
  background: var(--color-bg);
  padding: 0.5rem 1rem;
  border-radius: var(--border-radius);
  border: 1px solid var(--color-rule);
}
.time-zones span span {
  background: none;
  border: none;
  padding: 0;
  font-weight: 600;
  color: var(--color-text);
  font-family: "Outfit", monospace;
  font-size: 1rem;
}

/* =========================================================
   Meta / contact lines (legacy)
   ========================================================= */
.contact-line,
.meta-line {
  margin: 0.5rem 0;
  color: var(--color-text);
  max-width: 72ch;
}

/* =========================================================
   Responsive
   ========================================================= */
@media (max-width: 900px) {
  .site-hero {
    grid-template-columns: 1fr;
    padding: var(--space-5) 0 var(--space-4);
    gap: var(--space-4);
    text-align: center;
  }
  
  .site-hero::before {
    display: none;
  }

  .site-hero__photo-wrap {
    order: -1;
    justify-self: center;
  }
  
  .site-hero__statement {
    margin-left: auto;
    margin-right: auto;
  }

  .site-hero__photo {
    width: 200px;
    height: 200px;
  }

  .grid-3 {
    grid-template-columns: 1fr;
    gap: var(--space-4);
  }

  .grid-2 {
    grid-template-columns: 1fr;
    gap: var(--space-4);
  }
}

@media (max-width: 768px) {
  .site-header {
    padding: 0.75rem 0;
  }

  .site-header .site-wrap {
    gap: 0.5rem 1rem;
  }

  .site-header__mark {
    font-size: 1.1rem;
  }

  .site-nav__list {
    gap: 0.25rem 1rem;
  }

  .site-nav__link,
  .dropdown-toggle {
    font-size: 0.9rem;
    padding: 0.4rem 0;
  }

  .dropdown-menu {
    right: auto;
    left: 0;
  }
  
  .cv-group {
    padding-left: 1rem;
  }
  .cv-group::before {
    left: 0;
  }
  .cv-entry::before {
    left: -1.3rem;
  }

  .cv-entry,
  .talk {
    grid-template-columns: 1fr;
    gap: 0.5rem;
  }

  .cv-entry__year,
  .talk__year {
    font-size: 1rem;
  }

  .contact-info .contact-line {
    flex-direction: column;
    gap: 0.25rem;
  }
  .contact-info .contact-label {
    min-width: auto;
  }

  .page-head {
    padding: var(--space-4) 0 var(--space-3);
  }
  
  .ref-entry {
    padding: var(--space-3);
  }
}