:root {
  --ink: #1c2530;
  --muted: #5b6b7b;
  --accent: #2563eb;
  --accent-dark: #1d4ed8;
  --bg: #ffffff;
  --bg-alt: #f5f7fa;
  --line: #e3e8ef;
  --card-bg: #ffffff;
  --radius: 12px;
  --shadow: 0 1px 3px rgba(16, 24, 40, 0.08), 0 4px 16px rgba(16, 24, 40, 0.05);
  --maxw: 1080px;
}

* { box-sizing: border-box; margin: 0; padding: 0; }

html { scroll-behavior: smooth; }

body {
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", "PingFang SC",
    "Hiragino Sans GB", "Microsoft YaHei", "Noto Sans CJK SC", sans-serif;
  color: var(--ink);
  background: var(--bg);
  line-height: 1.7;
  font-size: 16px;
}

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

.container { max-width: var(--maxw); margin: 0 auto; padding: 0 24px; }

/* ---------- Header ---------- */
.site-header {
  position: sticky;
  top: 0;
  z-index: 50;
  background: rgba(255, 255, 255, 0.92);
  backdrop-filter: blur(8px);
  border-bottom: 1px solid var(--line);
}

.nav-wrap {
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: 64px;
}

.brand {
  font-size: 18px;
  font-weight: 700;
  color: var(--ink);
}

.brand span { color: var(--muted); font-weight: 500; font-size: 14px; margin-left: 6px; }

.nav { display: flex; gap: 22px; flex-wrap: wrap; }
.nav a { color: var(--muted); font-size: 14.5px; }
.nav a:hover { color: var(--accent); }

/* ---------- Hero ---------- */
.hero {
  background: linear-gradient(135deg, #0f2238 0%, #16324f 55%, #1d4ed8 130%);
  color: #fff;
  padding: 88px 0 76px;
}

.hero-kicker {
  color: #9fc1ff;
  letter-spacing: 0.04em;
  font-size: 14px;
  text-transform: uppercase;
  margin-bottom: 14px;
}

.hero h1 { font-size: 52px; letter-spacing: 0.06em; margin-bottom: 18px; }

.hero h1 .name-tag {
  display: inline-block;
  vertical-align: middle;
  margin-left: 14px;
  font-size: 14px;
  letter-spacing: 0.12em;
  font-weight: 600;
  color: #ffd7d7;
  background: rgba(185, 28, 28, 0.85);
  border: 1px solid rgba(255, 255, 255, 0.35);
  border-radius: 6px;
  padding: 3px 10px;
  line-height: 1.4;
}

.hero-sub { max-width: 720px; color: #d7e3f5; font-size: 17px; margin-bottom: 30px; }

.hero-actions { display: flex; gap: 14px; flex-wrap: wrap; }

.btn {
  display: inline-block;
  padding: 11px 22px;
  border-radius: 999px;
  font-size: 15px;
  font-weight: 600;
  transition: all 0.18s ease;
}

.btn-primary { background: #fff; color: var(--accent-dark); }
.btn-primary:hover { background: #e8efff; color: var(--accent-dark); }
.btn-ghost { border: 1px solid rgba(255, 255, 255, 0.55); color: #fff; }
.btn-ghost:hover { background: rgba(255, 255, 255, 0.12); color: #fff; }
.section .record-link {
  border-color: var(--line);
  color: var(--accent);
}
.section .record-link:hover {
  background: #eaf1ff;
  color: var(--accent-dark);
}

/* ---------- Sections ---------- */
.section { padding: 68px 0; }
.section-alt { background: var(--bg-alt); }

.section h2 {
  font-size: 28px;
  margin-bottom: 8px;
  position: relative;
  padding-left: 16px;
}

.section h2::before {
  content: "";
  position: absolute;
  left: 0;
  top: 8px;
  bottom: 8px;
  width: 5px;
  border-radius: 3px;
  background: var(--accent);
}

.lead { color: var(--muted); margin: 14px 0 28px; max-width: 820px; }

.grid-about {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(260px, 1fr));
  gap: 20px;
  margin: 24px 0 20px;
}

.about-card {
  background: var(--card-bg);
  border: 1px solid var(--line);
  border-radius: var(--radius);
  padding: 22px;
  box-shadow: var(--shadow);
}

.about-card h3 { font-size: 16px; margin-bottom: 10px; color: var(--accent-dark); }
.about-card ul { list-style: none; }
.about-card li { font-size: 14.5px; color: #334155; margin-bottom: 9px; line-height: 1.6; }

.about-note {
  background: #fbf6ea;
  border-left: 3px solid #d97706;
  color: #6b4e12;
  padding: 13px 16px;
  border-radius: 6px;
  font-size: 14px;
  margin-top: 8px;
}

.research-list {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(220px, 1fr));
  gap: 18px;
}

.research-item {
  background: var(--card-bg);
  border: 1px solid var(--line);
  border-radius: var(--radius);
  padding: 20px;
}

.research-item h3 { font-size: 15.5px; color: var(--accent-dark); margin-bottom: 8px; }
.research-item p { font-size: 14px; color: var(--muted); }

/* ---------- Publications ---------- */
.pub-list { display: flex; flex-direction: column; gap: 14px; }

.pub-card {
  display: flex;
  gap: 18px;
  background: var(--card-bg);
  border: 1px solid var(--line);
  border-radius: var(--radius);
  padding: 18px 20px;
  box-shadow: var(--shadow);
  transition: transform 0.15s ease, box-shadow 0.15s ease;
}

.pub-card:hover { transform: translateY(-2px); box-shadow: 0 6px 22px rgba(16, 24, 40, 0.1); }

.pub-year {
  flex: 0 0 52px;
  height: 52px;
  display: flex;
  align-items: center;
  justify-content: center;
  background: #eaf1ff;
  color: var(--accent-dark);
  font-weight: 700;
  border-radius: 10px;
  font-size: 15px;
}

.pub-body h3 { font-size: 16px; line-height: 1.5; margin-bottom: 4px; }
.pub-body .venue { color: var(--muted); font-size: 13.5px; margin-bottom: 10px; }

.pub-links { display: flex; gap: 16px; align-items: center; flex-wrap: wrap; }
.pub-links a { font-size: 13.5px; font-weight: 600; }
.pdf-link {
  display: inline-block;
  background: var(--accent);
  color: #fff !important;
  padding: 6px 14px;
  border-radius: 999px;
}
.pdf-link:hover { background: var(--accent-dark); }
.doi { font-size: 13.5px; font-weight: 600; }
.doi:not(.pub-links span) { color: var(--accent); }

.center { text-align: center; margin-top: 30px; }

/* ---------- Record ---------- */
.record-box {
  background: var(--card-bg);
  border: 1px solid var(--line);
  border-left: 4px solid #b91c1c;
  border-radius: var(--radius);
  padding: 20px 22px;
  margin: 20px 0;
  box-shadow: var(--shadow);
  font-size: 15px;
}

.record-src { color: var(--muted); font-size: 13px; margin-top: 10px; }

/* ---------- Papers page ---------- */
.page-head {
  background: var(--bg-alt);
  padding: 52px 0 42px;
  border-bottom: 1px solid var(--line);
}

.page-head h1 { font-size: 34px; margin-bottom: 8px; }
.page-head p { color: var(--muted); }

.controls {
  display: flex;
  gap: 14px;
  align-items: center;
  flex-wrap: wrap;
  margin-bottom: 26px;
}

.controls input,
.controls select {
  font: inherit;
  padding: 10px 14px;
  border: 1px solid var(--line);
  border-radius: 10px;
  background: #fff;
  color: var(--ink);
  min-width: 240px;
}

.controls input:focus,
.controls select:focus {
  outline: none;
  border-color: var(--accent);
  box-shadow: 0 0 0 3px rgba(37, 99, 235, 0.12);
}

.count { margin-left: auto; color: var(--muted); font-size: 14px; }

/* ---------- Record page ---------- */
.record-article {
  max-width: 860px;
  background: var(--card-bg);
  border: 1px solid var(--line);
  border-radius: var(--radius);
  padding: 36px 40px;
  box-shadow: var(--shadow);
  font-size: 15.5px;
}

.record-article h2 { font-size: 24px; line-height: 1.45; margin-bottom: 6px; }
.record-article .record-meta { color: var(--muted); font-size: 13.5px; margin-bottom: 22px; }
.record-article p { margin-bottom: 16px; text-align: justify; }

.table-wrap { overflow-x: auto; margin: 20px 0; }

.record-article table {
  width: 100%;
  border-collapse: collapse;
  font-size: 14px;
  min-width: 640px;
}

.record-article th,
.record-article td {
  border: 1px solid var(--line);
  padding: 10px 12px;
  text-align: left;
  vertical-align: top;
}

.record-article th {
  background: var(--bg-alt);
  font-weight: 600;
  white-space: nowrap;
}

.record-article tbody tr:nth-child(even) { background: #fafbfd; }

.record-article .record-sign { text-align: right; margin-top: 26px; line-height: 1.9; }

.record-article .record-h3 {
  margin-top: 40px;
  padding-top: 26px;
  border-top: 1px solid var(--line);
  font-size: 20px;
}

.record-article h4 {
  font-size: 16px;
  color: var(--accent-dark);
  margin: 22px 0 10px;
}

.record-article .record-ul {
  list-style: disc;
  padding-left: 22px;
  margin-bottom: 16px;
}

.record-article .record-ul li { margin-bottom: 8px; font-size: 14.5px; }

.record-article .record-note {
  margin-top: 24px;
  padding: 13px 16px;
  background: #fbf6ea;
  border-left: 3px solid #d97706;
  border-radius: 6px;
  color: #6b4e12;
  font-size: 13.5px;
}

.record-source {
  margin-top: 30px;
  padding: 16px 18px;
  background: var(--bg-alt);
  border: 1px solid var(--line);
  border-radius: 8px;
  font-size: 13.5px;
  color: var(--muted);
}

.record-source p { margin-bottom: 4px; }
.record-source a { word-break: break-all; }

/* ---------- Footer ---------- */
.site-footer {
  border-top: 1px solid var(--line);
  background: var(--bg-alt);
  padding: 34px 0;
  color: var(--muted);
  font-size: 13.5px;
}

.footer-note { margin-top: 4px; font-size: 12.5px; }

/* ---------- Responsive ---------- */
@media (max-width: 720px) {
  .hero { padding: 64px 0 56px; }
  .hero h1 { font-size: 38px; }
  .nav-wrap { height: auto; padding: 14px 0; flex-direction: column; gap: 10px; }
  .section { padding: 52px 0; }
  .pub-card { flex-direction: column; gap: 10px; }
  .count { margin-left: 0; }
  .controls input { min-width: 100%; }
  .record-article { padding: 26px 22px; }
}