:root {
  --bg: #fafafa;
  --fg: #1a1a1a;
  --muted: #5e5e5e;
  --accent: #2563eb;
  --card: #ffffff;
  --border: #e5e7eb;
  --code-bg: #0f172a;
  --code-fg: #e2e8f0;
  --header-bg: color-mix(in srgb, #ffffff 86%, transparent);
  --shadow-sm: 0 1px 2px 0 rgb(0 0 0 / 0.05);
  --shadow-md: 0 4px 6px -1px rgb(0 0 0 / 0.1), 0 2px 4px -2px rgb(0 0 0 / 0.1);
  --shadow-hover: 0 10px 15px -3px rgb(0 0 0 / 0.1), 0 4px 6px -4px rgb(0 0 0 / 0.1);
  --date-color: var(--accent); 
}

@media (prefers-color-scheme: dark) {
  :root:not([data-theme="light"]) {
    --bg: #0b0c10;
    --fg: #e5e7eb;
    --muted: #a1a1aa;
    --accent: #60a5fa;
    --card: #15161c;
    --border: #262b36;
    --code-bg: #050811;
    --code-fg: #cbd5e1;
    --header-bg: color-mix(in srgb, #0b0c10 86%, transparent);
    --shadow-sm: 0 1px 2px 0 rgb(0 0 0 / 0.5);
    --shadow-md: 0 4px 6px -1px rgb(0 0 0 / 0.5);
    --shadow-hover: 0 10px 15px -3px rgb(0 0 0 / 0.6);
  }
}

:root[data-theme="dark"] {
  --bg: #0b0c10;
  --fg: #e5e7eb;
  --muted: #a1a1aa;
  --accent: #60a5fa;
  --card: #15161c;
  --border: #262b36;
  --code-bg: #050811;
  --code-fg: #cbd5e1;
  --header-bg: color-mix(in srgb, #0b0c10 86%, transparent);
  --shadow-sm: 0 1px 2px 0 rgb(0 0 0 / 0.5);
  --shadow-md: 0 4px 6px -1px rgb(0 0 0 / 0.5);
  --shadow-hover: 0 10px 15px -3px rgb(0 0 0 / 0.6);
}

* { box-sizing: border-box; }
html {
  scroll-behavior: smooth;
  scroll-padding-top: 90px;
  overflow-y: scroll; 
}
html[data-site-loading="true"] body::before {
  content: "Loading...";
  position: fixed;
  inset: 0;
  background:
    radial-gradient(circle at 18% 18%, color-mix(in srgb, var(--accent) 16%, transparent), transparent 28%),
    radial-gradient(circle at 82% 16%, color-mix(in srgb, var(--accent) 10%, transparent), transparent 24%),
    color-mix(in srgb, var(--bg) 92%, white 8%);
  z-index: 4000;
  display: grid;
  place-items: center;
  color: var(--muted);
  font-size: 0.9rem;
  font-weight: 600;
  letter-spacing: 0.12em;
  text-transform: uppercase;
  padding-top: 88px;
  pointer-events: none;
  opacity: 1;
  visibility: visible;
}
html[data-site-loading="true"] body::after {
  content: "";
  position: fixed;
  top: 50%;
  left: 50%;
  width: 56px;
  height: 56px;
  margin: -72px 0 0 -28px;
  border-radius: 50%;
  border: 4px solid color-mix(in srgb, var(--accent) 16%, var(--border));
  border-top-color: var(--accent);
  border-right-color: color-mix(in srgb, var(--accent) 55%, var(--border));
  box-shadow: 0 0 0 6px color-mix(in srgb, var(--accent) 8%, transparent);
  animation: site-loader-spin 0.8s linear infinite;
  z-index: 4001;
  pointer-events: none;
}
@keyframes site-loader-spin {
  to { transform: rotate(360deg); }
}
html, body { margin: 0; padding: 0; }
body {
  background: var(--bg);
  color: var(--fg);
  font: 16px/1.65 'Inter', system-ui, -apple-system, Segoe UI, Roboto, Helvetica, Arial, "Apple Color Emoji", "Segoe UI Emoji";
  transition: background-color 0.3s ease, color 0.3s ease;
}
a { color: var(--accent); text-decoration: none; transition: color 0.2s; }
a:hover { text-decoration: underline; }
.container { max-width: 1280px; margin: 0 auto; padding: 80px 24px 24px 24px; }
.grid { display: flex; gap: 1.5rem; }
.col-4 { flex: 0 0 500px; }
.col-8 { flex: 1; }

/* Navbar */
.header {
  position: fixed;
  top: 0; left: 0; width: 100%;
  backdrop-filter: saturate(180%) blur(12px);
  -webkit-backdrop-filter: saturate(180%) blur(12px);
  border-bottom: 1px solid var(--border);
  background: var(--header-bg); 
  z-index: 1000;
  box-shadow: var(--shadow-sm);
}
.brand { display: flex; align-items: center; font-weight: 700; letter-spacing: .2px; }
nav { display: flex; gap: 6px; flex-wrap: wrap; align-items: center; }
.navbar { display: flex; align-items: center; justify-content: space-between; max-width: 1280px; margin: 0 auto; padding: 12px 24px; }
.navbar a.nav-link { padding: 8px 12px; border-radius: 8px; color: var(--fg); font-weight: 500; transition: background-color 0.2s, color 0.2s; }
.navbar a.nav-link:hover { background: var(--border); text-decoration: none; }
.navbar a[aria-current="page"] { background: var(--border); color: var(--accent); text-decoration: none; }

/* 关键修复：防跳动的固定宽高主题按钮 */
.theme-toggle-btn {
  background: transparent; 
  border: none; 
  color: var(--fg); 
  font-size: 1.15rem;
  cursor: pointer; 
  width: 36px;       /* 强制固定宽度 */
  height: 36px;      /* 强制固定高度 */
  padding: 0;        /* 移除自适应内边距 */
  margin-left: 8px; 
  border-radius: 8px;
  transition: background 0.2s, color 0.2s; 
  display: inline-flex; 
  align-items: center; 
  justify-content: center;
}
.theme-toggle-btn:hover { background: var(--border); color: var(--accent); }
.theme-toggle-btn i {
  width: 1.2rem;     /* 强制图标占据同样宽度的物理空间 */
  text-align: center;
}

.dropdown { position: relative; display: inline-block; }
.dropdown-content {
  visibility: hidden; opacity: 0; position: absolute; top: 100%; left: 0;
  background-color: var(--card); min-width: 180px; box-shadow: var(--shadow-md);
  z-index: 1001; border-radius: 8px; border: 1px solid var(--border); padding: 8px 0;
  transform: translateY(10px); transition: opacity 0.3s ease, transform 0.3s ease, visibility 0.3s;
}
.dropdown:hover .dropdown-content { visibility: visible; opacity: 1; transform: translateY(0); }
.dropdown-content a { color: var(--fg); padding: 10px 16px; text-decoration: none; display: block; font-size: 0.95rem; transition: background-color 0.2s; }
.dropdown-content a:hover { background-color: var(--border); color: var(--accent); text-decoration: none; }

/* Hero Section */
.hero { padding: 64px 0 40px; text-align: left; }
.hero h1 { font-size: clamp(32px, 5vw, 48px); margin: 0 0 12px; font-weight: 800; letter-spacing: -0.5px; }
.hero p { margin: 0; color: var(--muted); }
.section { padding: 24px 0; }
.social-links { display: flex; flex-wrap: wrap; gap: 16px; margin-top: 24px; }
.social-links a { display: inline-flex; align-items: center; padding: 8px 16px; background: var(--card); border: 1px solid var(--border); border-radius: 24px; color: var(--fg); font-weight: 500; box-shadow: var(--shadow-sm); transition: transform 0.2s ease, color 0.2s ease, border-color 0.2s ease, box-shadow 0.2s ease; }
.social-links a:hover { transform: translateY(-2px); color: var(--accent); border-color: var(--accent); box-shadow: var(--shadow-md); text-decoration: none; }
.social-links a i { margin-right: 8px; font-size: 1.1em; }

/* Bio 卡片化 */
.timeline-card {
  display: flex; flex-direction: column; background: var(--card); border: 1px solid var(--border);
  border-left: 4px solid var(--date-color); border-radius: 12px; padding: 20px 24px; margin-bottom: 20px;
  box-shadow: var(--shadow-sm); transition: transform 0.2s ease, box-shadow 0.2s ease;
}
.timeline-card:hover { transform: translateY(-2px); box-shadow: var(--shadow-md); }
.timeline-header { display: flex; flex-wrap: wrap; justify-content: space-between; align-items: baseline; margin-bottom: 8px; }
.timeline-date { color: var(--date-color); font-weight: 700; font-size: 0.95rem; letter-spacing: 0.5px; }
.timeline-location { color: var(--date-color); font-size: 0.9rem; font-weight: 600; }
.timeline-title { font-size: 1.25rem; font-weight: 700; margin: 0 0 4px 0; color: var(--fg); }
.timeline-subtitle { font-size: 1rem; color: var(--muted); margin: 0 0 12px 0; font-style: italic; }
.timeline-card ul { margin: 0; padding-left: 20px; }
.timeline-card li { margin-bottom: 4px; color: var(--fg); opacity: 0.9; }

/* 全新 Service 块结构 */
.service-category {
  margin-bottom: 24px;
  border: 1px solid var(--border);
  border-radius: 8px;
  overflow: hidden;
  background: var(--card);
}
.service-header {
  background: color-mix(in srgb, var(--border) 60%, transparent);
  padding: 12px 20px;
  font-weight: 700;
  color: var(--fg);
  font-size: 1.05rem;
}
.service-list { list-style: none; padding: 0; margin: 0; }
.service-item {
  padding: 14px 20px;
  border-top: 1px solid var(--border);
  color: var(--fg);
  font-size: 0.95rem;
  line-height: 1.5;
  display: flex;
  align-items: flex-start;
}
.service-item::before {
  content: "·";
  font-weight: bold;
  margin-right: 12px;
  font-size: 1.2rem;
  line-height: 1;
}

/* Card通用 */
.card { background: var(--card); border: 1px solid var(--border); border-radius: 16px; padding: 24px; box-shadow: var(--shadow-sm); transition: transform 0.3s ease, box-shadow 0.3s ease, border-color 0.3s ease; }
.card:hover { transform: translateY(-4px); box-shadow: var(--shadow-hover); border-color: var(--accent); }
.grid { display: grid; grid-template-columns: repeat(12, 1fr); gap: 20px; }
.col-4 { grid-column: span 4; }
.col-6 { grid-column: span 6; }
.col-12 { grid-column: span 12; }
@media (max-width: 860px) { .col-4, .col-6 { grid-column: span 12; } }

.footer { border-top: 1px solid var(--border); color: var(--muted); padding: 32px 24px; text-align: center; margin-top: 64px; font-size: 14px; }
.prose h1, .prose h2, .prose h3 { color: var(--fg); font-weight: 700; }
.prose h2 { margin-top: 36px; margin-bottom: 16px; border-bottom: 1px solid var(--border); padding-bottom: 8px; }
.prose h3 { margin-top: 24px; margin-bottom: 8px; }
.prose p, .prose li { color: var(--fg); opacity: 0.9; }
.prose blockquote { margin: 20px 0; padding: 12px 20px; border-left: 4px solid var(--accent); background: color-mix(in srgb, var(--accent) 10%, transparent); border-radius: 0 8px 8px 0; }
.prose code { background: var(--border); padding: 3px 6px; border-radius: 6px; font-family: monospace; font-size: 0.9em; }
pre { background: var(--code-bg); color: var(--code-fg); padding: 20px; border-radius: 12px; overflow: auto; box-shadow: inset 0 2px 4px rgba(0,0,0,0.1); }

/* Researches Filter & Cards */
.research-filters { display: flex; flex-wrap: wrap; gap: 12px; margin: 24px 0; }
.filter-btn { background: var(--card); border: 1px solid var(--border); color: var(--fg); padding: 8px 16px; border-radius: 20px; cursor: pointer; font-weight: 600; transition: all 0.2s ease; }
.filter-btn:hover { background: var(--border); }
.filter-btn.active { background: var(--accent); color: #fff; border-color: var(--accent); }

.research-grid { display: grid; grid-template-columns: repeat(auto-fill, minmax(320px, 1fr)); gap: 24px; }
.res-card { display: flex; flex-direction: column; background: var(--card); border: 1px solid var(--border); border-radius: 12px; overflow: hidden; transition: transform 0.2s, box-shadow 0.2s; text-decoration: none !important; color: inherit !important; }
.res-card:hover { transform: translateY(-5px); box-shadow: var(--shadow-hover); border-color: var(--accent); }
.res-card img {
  width: 100%;
  height: 220px;
  object-fit: contain;
  background: #fff;
  border-bottom: 1px solid var(--border);
  padding: 10px;
}
.res-card-content { padding: 20px; display: flex; flex-direction: column; flex: 1; }
.res-tag {
  align-self: flex-start;
  background: color-mix(in srgb, var(--accent) 15%, transparent);
  color: var(--accent);
  font-size: 0.8rem;
  font-weight: 700;
  padding: 4px 10px;
  border-radius: 12px;
  margin-bottom: 12px;
  text-transform: uppercase;
}
.res-card-title { font-size: 1.25rem; font-weight: 700; margin: 0 0 10px 0; }
.res-card-desc { font-size: 0.95rem; color: var(--muted); margin: 0; line-height: 1.5; }

/* Photo Grid */
.figure-grid { display: grid; grid-template-columns: repeat(auto-fit, minmax(350px, 1fr)); gap: 24px; padding: 24px 0; }
.figure-grid figure { margin: 0; cursor: pointer; transition: transform 0.3s ease; border-radius: 12px; overflow: hidden; background: var(--card); border: 1px solid var(--border); padding-bottom: 12px; box-shadow: var(--shadow-sm); }
.figure-grid figure:hover { transform: translateY(-5px); box-shadow: var(--shadow-hover); }
.figure-grid img { width: 100%; height: 400px; object-fit: cover; border-bottom: 1px solid var(--border); }
.figure-grid figcaption { text-align: center; font-size: 0.95rem; margin-top: 12px; font-weight: 500; color: var(--fg); }
@media (max-width: 480px) { .figure-grid { grid-template-columns: 1fr; } }

/* Modals */
.modal { display: none; position: fixed; z-index: 1000; left: 0; top: 0; width: 100%; height: 100%; background-color: rgba(0, 0, 0, 0.75); backdrop-filter: blur(4px); overflow: auto; animation: fadeIn 0.3s ease; }
@keyframes fadeIn { from { opacity: 0; } to { opacity: 1; } }
.modal-content { background-color: var(--card); color: var(--fg); margin: 5% auto; padding: 24px; border-radius: 12px; max-width: 800px; width: 90%; position: relative; box-shadow: 0 25px 50px -12px rgba(0, 0, 0, 0.5); border: 1px solid var(--border); }
.modal-close { position: absolute; top: 15px; right: 20px; font-size: 28px; cursor: pointer; color: var(--muted); transition: color 0.2s; }
.modal-close:hover { color: var(--fg); }
.modal-image-grid { display: grid; grid-template-columns: repeat(auto-fit, minmax(200px, 1fr)); gap: 16px; margin-top: 24px; }
.modal-image-grid img { width: 100%; height: 150px; border-radius: 8px; object-fit: cover; }

/* Pub */
.pub-grid { display: flex; flex-direction: column; gap: 20px; margin-top: 16px; margin-bottom: 32px; }
.pub-card { background: var(--card); border: 1px solid var(--border); border-radius: 12px; padding: 20px 24px; box-shadow: var(--shadow-sm); transition: transform 0.2s ease, box-shadow 0.2s ease, border-left 0.2s ease; border-left: 4px solid var(--border); }
.pub-card:hover { transform: translateX(4px); box-shadow: var(--shadow-md); border-left-color: var(--accent); }
.pub-title { font-size: 1.15rem; font-weight: 700; margin: 0 0 8px 0 !important; line-height: 1.4; border-bottom: none !important; padding-bottom: 0 !important; }
.pub-authors { color: var(--fg); margin: 0 0 6px 0 !important; font-size: 0.95rem; }
.pub-venue { color: var(--muted); margin: 0 0 16px 0 !important; font-size: 0.95rem; }
.pub-bottom { display: flex; justify-content: space-between; align-items: center; flex-wrap: wrap; gap: 16px; }
.pub-tags { display: flex; gap: 8px; flex-wrap: wrap; }
.pub-tag { background: color-mix(in srgb, var(--accent) 15%, transparent); color: var(--accent); font-size: 0.8rem; padding: 4px 10px; border-radius: 12px; font-weight: 600; cursor: pointer; transition: background 0.2s; }
.pub-tag:hover { background: var(--accent); color: #fff; }
.pub-links { display: flex; gap: 12px; flex-wrap: wrap; }
.pub-btn { display: inline-flex; align-items: center; gap: 6px; font-size: 0.85rem; font-weight: 600; padding: 6px 14px; border-radius: 6px; background: var(--bg); color: var(--fg); border: 1px solid var(--border); transition: all 0.2s ease; }
.pub-btn:hover { background: var(--accent); color: #fff; border-color: var(--accent); text-decoration: none; }
.pub-award { display: inline-flex; align-items: center; color: #d9534f; font-weight: bold; font-size: 0.9rem; gap: 4px; }
.pub-award:hover { text-decoration: underline; }

.search-box { margin: 1rem 0; width: 100%; box-sizing: border-box; padding: 12px; border: 1px solid var(--border); border-radius: 8px; background: var(--card); color: var(--fg); font-size: 1rem; outline: none; transition: border-color 0.2s; }
.search-box:focus { border-color: var(--accent); }