@import url('https://fonts.googleapis.com/css2?family=Inter:ital,opsz,wght@0,14..32,300;0,14..32,400;0,14..32,500;0,14..32,600;0,14..32,700;1,14..32,400&display=swap');

/* ===========================
   CSS Custom Properties
   =========================== */
:root {
  /* Default: Walnut — warm cream + amber-brown */
  --c-bg:      #faf6f0;
  --c-bg-2:    #f3ebe0;
  --c-bg-3:    #e9e0d5;

  /* Border */
  --c-border:  #ddd3c5;
  --c-border-2:#c9bdb0;

  /* Text */
  --c-text:    #1a0f07;
  --c-text-2:  #3d2b1a;
  --c-text-3:  #7a6555;
  --c-text-4:  #a89080;

  /* Accent — amber-brown */
  --c-accent:        #b45309;
  --c-accent-dark:   #92400e;
  --c-accent-darker: #78350f;
  --c-accent-bg:     #fef3c7;
  --c-accent-border: #fde68a;

  /* Semantic colours */
  --c-green:    #15803d;
  --c-green-bg: #f0fdf4;
  --c-amber:    #92400e;
  --c-amber-bg: #fffbeb;
  --c-amber-border: #fde68a;

  /* Nav backdrop */
  --c-nav-bg: rgba(250, 246, 240, 0.92);

  /* Layout */
  --nav-height:   60px;
  --max-width:    1100px;
  --sidebar-w:    250px;
  --gap:          36px;
  --section-gap:  52px;

  /* Shape */
  --radius:    12px;
  --radius-sm: 8px;
  --radius-xs: 5px;

  /* Shadow */
  --shadow-sm: 0 1px 2px rgba(0,0,0,.06);
  --shadow:    0 1px 3px rgba(0,0,0,.08), 0 1px 2px rgba(0,0,0,.04);
  --shadow-md: 0 4px 14px rgba(0,0,0,.08);
  --shadow-lg: 0 8px 28px rgba(0,0,0,.10);

  /* Motion */
  --t: 150ms ease;
}

/* ===========================
   Reset & Base
   =========================== */
*, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }

html {
  scroll-behavior: smooth;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}

body {
  font-family: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', sans-serif;
  background: var(--c-bg);
  color: var(--c-text);
  line-height: 1.6;
  min-height: 100vh;
  display: flex;
  flex-direction: column;
  font-size: 16px;
}

img { max-width: 100%; height: auto; display: block; }

a {
  color: var(--c-accent);
  text-decoration: none;
  transition: color var(--t);
}
a:hover { color: var(--c-accent-dark); }

/* ===========================
   Navigation
   =========================== */
.nav {
  position: sticky;
  top: 0;
  z-index: 100;
  height: var(--nav-height);
  background: var(--c-nav-bg);
  backdrop-filter: blur(10px);
  -webkit-backdrop-filter: blur(10px);
  border-bottom: 1px solid var(--c-border);
  display: flex;
  align-items: center;
}

.nav-inner {
  max-width: var(--max-width);
  width: 100%;
  margin: 0 auto;
  padding: 0 24px;
  display: flex;
  align-items: center;
  justify-content: space-between;
}

.nav-logo {
  display: flex;
  align-items: center;
  gap: 10px;
  color: var(--c-text);
  font-weight: 600;
  font-size: .95rem;
  letter-spacing: -.01em;
  transition: color var(--t);
}
.nav-logo:hover { color: var(--c-accent); }
.nav-logo img {
  width: 30px;
  height: 30px;
  object-fit: contain;
}

.nav-links {
  display: flex;
  align-items: center;
  gap: 2px;
  list-style: none;
}
.nav-links a {
  display: block;
  padding: 6px 13px;
  border-radius: var(--radius-sm);
  color: var(--c-text-2);
  font-size: .875rem;
  font-weight: 500;
  transition: all var(--t);
}
.nav-links a:hover, .nav-links a.active {
  color: var(--c-accent);
  background: var(--c-accent-bg);
}

/* ===========================
   Profile Layout  (index.html)
   =========================== */
.page {
  flex: 1;
  max-width: var(--max-width);
  width: 100%;
  margin: 0 auto;
  padding: 0 24px;
}

.profile-layout {
  display: grid;
  grid-template-columns: var(--sidebar-w) 1fr;
  gap: var(--gap);
  padding-top: 52px;
  padding-bottom: 80px;
  align-items: start;
}

/* --- Sidebar --- */
.sidebar {
  position: sticky;
  top: calc(var(--nav-height) + 24px);
}

.profile-photo-wrap {
  width: 200px;
  border-radius: var(--radius);
  overflow: hidden;
  margin-bottom: 18px;
  box-shadow: var(--shadow-md);
}
.profile-photo-wrap img { width: 100%; height: auto; display: block; }

.profile-name {
  font-size: 1.3rem;
  font-weight: 700;
  color: var(--c-text);
  letter-spacing: -.02em;
  line-height: 1.2;
  margin-bottom: 4px;
}
.profile-name-zh {
  font-size: 1rem;
  color: var(--c-text-4);
  font-weight: 400;
}
.profile-title {
  font-size: .83rem;
  color: var(--c-text-2);
  font-weight: 400;
  line-height: 1.4;
  margin-bottom: 20px;
}
.profile-institution-link {
  font-weight: 600;
  color: var(--c-accent);
  text-decoration: none;
}
.profile-institution-link:hover {
  text-decoration: underline;
}
.profile-institution {
  font-size: .83rem;
  color: var(--c-text-2);
  line-height: 1.5;
  margin-bottom: 14px;
}
.profile-badge {
  display: inline-block;
  background: var(--c-amber-bg);
  color: var(--c-amber);
  border: 1px solid var(--c-amber-border);
  border-radius: 20px;
  padding: 3px 11px;
  font-size: .75rem;
  font-weight: 500;
  margin-bottom: 18px;
  line-height: 1.5;
}

.social-links {
  display: flex;
  flex-wrap: wrap;
  gap: 7px;
}
.social-link {
  display: flex;
  align-items: center;
  justify-content: center;
  width: 34px;
  height: 34px;
  border-radius: var(--radius-sm);
  background: var(--c-bg-2);
  border: 1px solid var(--c-border);
  color: var(--c-text-3);
  font-size: .85rem;
  transition: all var(--t);
}
.social-link:hover {
  background: var(--c-accent-bg);
  border-color: var(--c-accent-border);
  color: var(--c-accent);
  transform: translateY(-1px);
  box-shadow: var(--shadow-sm);
}

/* --- Main Content --- */
.main-content { min-width: 0; }

.section { margin-bottom: var(--section-gap); }

.section-title {
  font-size: 1rem;
  font-weight: 600;
  color: var(--c-text);
  letter-spacing: -.01em;
  margin-bottom: 18px;
  padding-bottom: 10px;
  border-bottom: 1.5px solid var(--c-border);
}

/* Bio */
.bio {
  font-size: .93rem;
  color: var(--c-text-2);
  line-height: 1.78;
  margin-bottom: 14px;
}
.bio a {
  text-decoration: underline;
  text-decoration-color: var(--c-accent-border);
  text-underline-offset: 2px;
}
.bio a:hover { text-decoration-color: var(--c-accent); }

/* Tags */
.tag-list {
  display: flex;
  flex-wrap: wrap;
  gap: 7px;
  margin-top: 4px;
}
.tag {
  display: inline-block;
  padding: 4px 12px;
  border-radius: 20px;
  font-size: .78rem;
  font-weight: 500;
  white-space: nowrap;
}
.tag-research {
  background: var(--c-accent-bg);
  color: var(--c-accent-darker);
  border: 1px solid var(--c-accent-border);
}
.tag-venue {
  background: var(--c-bg-2);
  color: var(--c-text-3);
  border: 1px solid var(--c-border);
  font-size: .73rem;
  padding: 2px 9px;
}
.tag-award {
  background: var(--c-amber-bg);
  color: var(--c-amber);
  border: 1px solid var(--c-amber-border);
  font-size: .73rem;
  padding: 2px 9px;
}
.tag-conference {
  background: var(--c-accent-bg);
  color: var(--c-accent);
  border: 1px solid var(--c-accent-border);
  font-size: .73rem;
  padding: 2px 9px;
}
.tag-journal {
  background: var(--c-green-bg);
  color: var(--c-green);
  border: 1px solid #a7f3d0;
  font-size: .73rem;
  padding: 2px 9px;
}

/* News */
.news-list { list-style: none; }
.news-item {
  display: flex;
  gap: 16px;
  padding: 11px 0;
  border-bottom: 1px solid var(--c-border);
  font-size: .875rem;
}
.news-item:last-child { border-bottom: none; }
.news-date {
  flex-shrink: 0;
  color: var(--c-text-4);
  font-size: .78rem;
  font-weight: 500;
  width: 76px;
  padding-top: 2px;
  font-variant-numeric: tabular-nums;
}
.news-text {
  color: var(--c-text-2);
  line-height: 1.55;
}
.news-text a {
  text-decoration: underline;
  text-decoration-color: var(--c-accent-border);
  text-underline-offset: 2px;
}

/* News toggle */
.news-toggle {
  margin-top: 10px;
  background: none;
  border: none;
  padding: 0;
  font-family: inherit;
  font-size: .83rem;
  font-weight: 500;
  color: var(--c-accent);
  cursor: pointer;
  transition: color var(--t);
}
.news-toggle:hover { color: var(--c-accent-dark); }

/* Award tag links */
.tag-award a {
  color: inherit;
  text-decoration: underline;
  text-decoration-color: rgba(0,0,0,0.2);
  text-underline-offset: 2px;
}
.tag-award a:hover { text-decoration-color: currentColor; }

/* ===========================
   Publication Cards
   =========================== */
.pub-list {
  display: flex;
  flex-direction: column;
  gap: 16px;
}
.pub-card {
  background: var(--c-bg);
  border: 1px solid var(--c-border);
  border-radius: var(--radius);
  padding: 18px 20px;
  transition: all var(--t);
  position: relative;
  overflow: hidden;
}
.pub-card::before {
  content: '';
  position: absolute;
  left: 0; top: 0; bottom: 0;
  width: 3px;
  background: var(--c-accent);
  border-radius: 2px 0 0 2px;
  opacity: 0;
  transition: opacity var(--t);
}
.pub-card:hover {
  border-color: var(--c-accent-border);
  box-shadow: var(--shadow-md);
  transform: translateY(-1px);
}
.pub-card:hover::before { opacity: 1; }

.pub-tags {
  display: flex;
  flex-wrap: wrap;
  gap: 6px;
  margin-bottom: 9px;
}
.pub-title {
  font-size: .93rem;
  font-weight: 600;
  color: var(--c-text);
  margin-bottom: 6px;
  line-height: 1.45;
}
.pub-title a { color: inherit; transition: color var(--t); }
.pub-title a:hover { color: var(--c-accent); }

.pub-authors {
  font-size: .83rem;
  color: var(--c-text-4);
  margin-bottom: 4px;
  line-height: 1.5;
}
.pub-authors .self {
  color: var(--c-text-2);
  font-weight: 500;
}
.pub-venue {
  font-size: .83rem;
  color: var(--c-text-3);
  font-style: italic;
  margin-bottom: 10px;
}
.pub-links { display: flex; flex-wrap: wrap; gap: 7px; }
.pub-link {
  display: inline-flex;
  align-items: center;
  gap: 5px;
  padding: 3px 10px;
  border-radius: var(--radius-xs);
  font-size: .78rem;
  font-weight: 500;
  border: 1px solid var(--c-border);
  color: var(--c-text-3);
  background: var(--c-bg-2);
  transition: all var(--t);
}
.pub-link:hover {
  border-color: var(--c-accent-border);
  color: var(--c-accent);
  background: var(--c-accent-bg);
}

/* Year dividers (publications page) */
.year-group { margin-bottom: 40px; }
.year-label {
  font-size: .72rem;
  font-weight: 700;
  letter-spacing: .08em;
  text-transform: uppercase;
  color: var(--c-text-4);
  margin-bottom: 14px;
  display: flex;
  align-items: center;
  gap: 12px;
}
.year-label::after {
  content: '';
  flex: 1;
  height: 1px;
  background: var(--c-border);
}

/* ===========================
   Blog Tag Filter
   =========================== */
.tag-filter {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
  margin-bottom: 20px;
}
.tag-filter-btn {
  padding: 4px 14px;
  border-radius: 100px;
  border: 1px solid var(--c-border-2);
  background: transparent;
  color: var(--c-text-3);
  font-size: 0.8rem;
  font-family: inherit;
  cursor: pointer;
  transition: background 0.15s, color 0.15s, border-color 0.15s;
}
.tag-filter-btn:hover {
  border-color: var(--c-accent);
  color: var(--c-accent);
}
.tag-filter-btn.active {
  background: var(--c-accent);
  border-color: var(--c-accent);
  color: #fff;
}

/* ===========================
   Blog List
   =========================== */
.blog-list {
  display: flex;
  flex-direction: column;
  border: 1px solid var(--c-border);
  border-radius: var(--radius);
  overflow: hidden;
}
.blog-item {
  display: flex;
  align-items: center;
  gap: 20px;
  padding: 18px 22px;
  background: var(--c-bg);
  border-bottom: 1px solid var(--c-border);
  color: var(--c-text);
  transition: background var(--t);
  cursor: pointer;
}
.blog-item:last-child { border-bottom: none; }
.blog-item:hover { background: var(--c-bg-2); }

.blog-item-date {
  flex-shrink: 0;
  font-size: .78rem;
  color: var(--c-text-4);
  width: 90px;
  font-variant-numeric: tabular-nums;
}
.blog-item-content { flex: 1; min-width: 0; }
.blog-item-title {
  font-size: .93rem;
  font-weight: 600;
  color: var(--c-text);
  margin-bottom: 3px;
  white-space: nowrap;
  overflow: hidden;
  text-overflow: ellipsis;
}
.blog-item-desc {
  font-size: .83rem;
  color: var(--c-text-3);
  white-space: nowrap;
  overflow: hidden;
  text-overflow: ellipsis;
}
.blog-item-arrow {
  color: var(--c-text-4);
  font-size: 1rem;
  transition: all var(--t);
  flex-shrink: 0;
}
.blog-item:hover .blog-item-arrow {
  color: var(--c-accent);
  transform: translateX(4px);
}

/* ===========================
   Blog Post Page
   =========================== */
.blog-post-wrap {
  max-width: 720px;
  margin: 0 auto;
  padding: 48px 24px 80px;
}
.blog-back {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  color: var(--c-text-3);
  font-size: .85rem;
  margin-bottom: 28px;
  transition: color var(--t);
}
.blog-back:hover { color: var(--c-accent); }

.blog-post-title {
  font-size: 2rem;
  font-weight: 700;
  letter-spacing: -.03em;
  line-height: 1.2;
  color: var(--c-text);
  margin-bottom: 14px;
}
.blog-post-meta {
  display: flex;
  align-items: center;
  gap: 10px;
  color: var(--c-text-4);
  font-size: .83rem;
}
.blog-post-divider {
  height: 1px;
  background: var(--c-border);
  margin: 30px 0;
}

/* ===========================
   Markdown Rendered Content
   =========================== */
.markdown-content {
  font-size: .97rem;
  line-height: 1.82;
  color: var(--c-text-2);
}
.markdown-content h1,
.markdown-content h2,
.markdown-content h3,
.markdown-content h4 {
  color: var(--c-text);
  font-weight: 600;
  letter-spacing: -.01em;
  margin-top: 2em;
  margin-bottom: .5em;
  line-height: 1.3;
}
.markdown-content h1 { font-size: 1.7rem; }
.markdown-content h2 {
  font-size: 1.35rem;
  border-bottom: 1px solid var(--c-border);
  padding-bottom: 8px;
}
.markdown-content h3 { font-size: 1.12rem; }
.markdown-content h4 { font-size: 1rem; }

.markdown-content p { margin-bottom: 1em; }
.markdown-content ul, .markdown-content ol {
  margin-bottom: 1em;
  padding-left: 1.5em;
}
.markdown-content li { margin-bottom: .3em; }

.markdown-content a {
  color: var(--c-accent);
  text-decoration: underline;
  text-decoration-color: var(--c-accent-border);
  text-underline-offset: 2px;
}
.markdown-content a:hover { text-decoration-color: var(--c-accent); }

.markdown-content blockquote {
  border-left: 3px solid var(--c-accent);
  padding: 12px 20px;
  margin: 1.5em 0;
  background: var(--c-accent-bg);
  border-radius: 0 var(--radius-sm) var(--radius-sm) 0;
  color: var(--c-text-2);
  font-style: italic;
}

.markdown-content code {
  background: var(--c-bg-3);
  border: 1px solid var(--c-border);
  border-radius: 4px;
  padding: 2px 6px;
  font-family: 'Menlo', 'Monaco', 'Courier New', monospace;
  font-size: .84em;
  color: var(--c-accent-dark);
}
.markdown-content pre {
  background: #1e293b;
  border-radius: var(--radius-sm);
  padding: 20px;
  overflow-x: auto;
  margin: 1.5em 0;
}
.markdown-content pre code {
  background: none;
  border: none;
  padding: 0;
  color: #e2e8f0;
  font-size: .88rem;
  line-height: 1.65;
}
.markdown-content img {
  border-radius: var(--radius-sm);
  margin: 1.5em 0;
  max-width: 100%;
}
.markdown-content hr {
  border: none;
  border-top: 1px solid var(--c-border);
  margin: 2em 0;
}
.markdown-content table {
  width: 100%;
  border-collapse: collapse;
  margin: 1.5em 0;
  font-size: .9rem;
}
.markdown-content th,
.markdown-content td {
  border: 1px solid var(--c-border);
  padding: 8px 13px;
  text-align: left;
}
.markdown-content th {
  background: var(--c-bg-2);
  font-weight: 600;
  color: var(--c-text);
}
.markdown-content tr:nth-child(even) td { background: var(--c-bg-2); }

/* ===========================
   Shared Page Wrapper (non-sidebar)
   =========================== */
.page-full {
  flex: 1;
  max-width: var(--max-width);
  width: 100%;
  margin: 0 auto;
  padding: 52px 24px 80px;
}
.page-header { margin-bottom: 36px; }
.page-title {
  font-size: 1.65rem;
  font-weight: 700;
  letter-spacing: -.03em;
  color: var(--c-text);
  margin-bottom: 6px;
}
.page-subtitle { font-size: .88rem; color: var(--c-text-3); }

/* ===========================
   Footer
   =========================== */
.footer {
  margin-top: auto;
  padding: 22px 24px;
  text-align: center;
  font-size: .78rem;
  color: var(--c-text-4);
  border-top: 1px solid var(--c-border);
}
.footer a { color: var(--c-text-3); }
.footer a:hover { color: var(--c-accent); }

/* ===========================
   States
   =========================== */
.loading {
  display: flex;
  align-items: center;
  justify-content: center;
  padding: 64px;
  color: var(--c-text-4);
  font-size: .9rem;
}
.empty-state {
  text-align: center;
  padding: 64px 24px;
  color: var(--c-text-3);
}
.empty-state p { font-size: .9rem; }

/* ===========================
   Responsive
   =========================== */
@media (max-width: 800px) {
  .profile-layout {
    grid-template-columns: 1fr;
    padding-top: 36px;
  }
  .sidebar {
    position: static;
    display: flex;
    flex-direction: column;
    align-items: center;
    text-align: center;
  }
  .social-links { justify-content: center; }
  .blog-item-date { display: none; }
  .blog-post-title { font-size: 1.5rem; }
  .page-title { font-size: 1.35rem; }
}

@media (max-width: 500px) {
  .nav-inner, .page, .page-full, .blog-post-wrap { padding-left: 16px; padding-right: 16px; }
  .pub-card { padding: 14px 16px; }
  .nav-logo span { display: none; }
  .nav-links a { padding: 6px 9px; font-size: .8rem; }
}