/* ========================================
   课题组网站 - 全局样式
   参考风格：学术科研团队官网
   ======================================== */

:root {
  --primary: #1a4f8b;
  --primary-dark: #0d3460;
  --primary-light: #2a6cb0;
  --accent: #c8a45c;
  --accent-hover: #b8903f;
  --text: #333;
  --text-light: #666;
  --text-muted: #999;
  --bg: #fff;
  --bg-gray: #f5f7fa;
  --bg-dark: #1a2332;
  --border: #e5e8eb;
  --shadow: 0 2px 12px rgba(0, 0, 0, 0.08);
  --shadow-hover: 0 8px 24px rgba(0, 0, 0, 0.12);
  --radius: 8px;
  --header-h: 72px;
  --transition: 0.3s ease;
  --font: "PingFang SC", "Microsoft YaHei", "Helvetica Neue", Arial, sans-serif;
  --font-en: "Helvetica Neue", Arial, sans-serif;
  --max-w: 1200px;
}

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

html {
  scroll-behavior: smooth;
  font-size: 16px;
}

body {
  font-family: var(--font);
  color: var(--text);
  background: var(--bg);
  line-height: 1.7;
  min-height: 100vh;
  display: flex;
  flex-direction: column;
}

a {
  color: inherit;
  text-decoration: none;
  transition: color var(--transition);
}

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

ul,
ol {
  list-style: none;
}

button {
  font-family: inherit;
  cursor: pointer;
  border: none;
  background: none;
}

.container {
  width: 100%;
  max-width: var(--max-w);
  margin: 0 auto;
  padding: 0 24px;
}

/* ========== Header ========== */
.site-header {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  z-index: 1000;
  height: var(--header-h);
  background: rgba(255, 255, 255, 0.95);
  backdrop-filter: blur(10px);
  border-bottom: 1px solid transparent;
  transition: all var(--transition);
}

.site-header.scrolled {
  box-shadow: var(--shadow);
  border-bottom-color: var(--border);
}

.site-header .header-inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: var(--header-h);
  max-width: var(--max-w);
  margin: 0 auto;
  padding: 0 24px;
}

.logo {
  display: flex;
  align-items: center;
  gap: 12px;
  flex-shrink: 0;
}

.logo-mark {
  width: 42px;
  height: 42px;
  background: linear-gradient(135deg, var(--primary), var(--primary-light));
  border-radius: 10px;
  display: flex;
  align-items: center;
  justify-content: center;
  color: #fff;
  font-weight: 700;
  font-size: 18px;
  letter-spacing: -0.5px;
}

.logo-text {
  display: flex;
  flex-direction: column;
}

.logo-text .cn {
  font-size: 16px;
  font-weight: 600;
  color: var(--primary-dark);
  line-height: 1.3;
}

.logo-text .en {
  font-size: 11px;
  color: var(--text-muted);
  font-family: var(--font-en);
  letter-spacing: 0.3px;
}

.nav-main {
  display: flex;
  align-items: center;
  gap: 4px;
}

.nav-main a {
  padding: 8px 14px;
  font-size: 15px;
  color: var(--text);
  border-radius: 6px;
  position: relative;
  white-space: nowrap;
}

.nav-main a:hover,
.nav-main a.active {
  color: var(--primary);
}

.nav-main a.active::after {
  content: "";
  position: absolute;
  bottom: 2px;
  left: 14px;
  right: 14px;
  height: 2px;
  background: var(--primary);
  border-radius: 1px;
}

.header-actions {
  display: flex;
  align-items: center;
  gap: 12px;
}

.lang-switch {
  padding: 6px 12px;
  font-size: 13px;
  font-weight: 600;
  color: var(--primary);
  border: 1px solid var(--primary);
  border-radius: 4px;
  transition: all var(--transition);
}

.lang-switch:hover {
  background: var(--primary);
  color: #fff;
}

.menu-toggle {
  display: none;
  flex-direction: column;
  gap: 5px;
  padding: 8px;
  z-index: 1001;
}

.menu-toggle span {
  display: block;
  width: 22px;
  height: 2px;
  background: var(--text);
  border-radius: 1px;
  transition: all var(--transition);
}

.menu-toggle.open span:nth-child(1) {
  transform: translateY(7px) rotate(45deg);
}

.menu-toggle.open span:nth-child(2) {
  opacity: 0;
}

.menu-toggle.open span:nth-child(3) {
  transform: translateY(-7px) rotate(-45deg);
}

/* ========== Hero / Banner ========== */
.hero {
  position: relative;
  margin-top: var(--header-h);
  height: 480px;
  overflow: hidden;
  background: var(--primary-dark);
}

.hero-slides {
  position: relative;
  width: 100%;
  height: 100%;
}

.hero-slide {
  position: absolute;
  inset: 0;
  opacity: 0;
  transition: opacity 0.8s ease;
  background-size: cover;
  background-position: center;
}

.hero-slide.active {
  opacity: 1;
}

.hero-slide::before {
  content: "";
  position: absolute;
  inset: 0;
  background: linear-gradient(
    135deg,
    rgba(13, 52, 96, 0.75) 0%,
    rgba(26, 79, 139, 0.5) 50%,
    rgba(13, 52, 96, 0.4) 100%
  );
}

.hero-slide .hero-content {
  position: relative;
  z-index: 1;
  height: 100%;
  display: flex;
  flex-direction: column;
  justify-content: center;
  max-width: var(--max-w);
  margin: 0 auto;
  padding: 0 24px;
  color: #fff;
}

.hero-content h1 {
  font-size: 42px;
  font-weight: 700;
  margin-bottom: 16px;
  line-height: 1.3;
  text-shadow: 0 2px 8px rgba(0, 0, 0, 0.2);
}

.hero-content p {
  font-size: 18px;
  opacity: 0.9;
  max-width: 560px;
  margin-bottom: 28px;
}

.btn {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 12px 28px;
  font-size: 15px;
  font-weight: 500;
  border-radius: 6px;
  transition: all var(--transition);
}

.btn-primary {
  background: var(--accent);
  color: #fff;
}

.btn-primary:hover {
  background: var(--accent-hover);
  transform: translateY(-1px);
}

.btn-outline {
  background: transparent;
  color: #fff;
  border: 1.5px solid rgba(255, 255, 255, 0.7);
}

.btn-outline:hover {
  background: rgba(255, 255, 255, 0.15);
  border-color: #fff;
}

.hero-dots {
  position: absolute;
  bottom: 24px;
  left: 50%;
  transform: translateX(-50%);
  display: flex;
  gap: 10px;
  z-index: 2;
}

.hero-dots button {
  width: 10px;
  height: 10px;
  border-radius: 50%;
  background: rgba(255, 255, 255, 0.4);
  transition: all var(--transition);
}

.hero-dots button.active {
  background: #fff;
  width: 28px;
  border-radius: 5px;
}

/* ========== Section common ========== */
.section {
  padding: 72px 0;
}

.section-gray {
  background: var(--bg-gray);
}

.section-header {
  display: flex;
  align-items: flex-end;
  justify-content: space-between;
  margin-bottom: 40px;
}

.section-title {
  position: relative;
}

.section-title h2 {
  font-size: 28px;
  font-weight: 700;
  color: var(--primary-dark);
  line-height: 1.3;
}

.section-title .en-sub {
  font-size: 13px;
  color: var(--text-muted);
  font-family: var(--font-en);
  letter-spacing: 1px;
  text-transform: uppercase;
  margin-top: 4px;
}

.section-title::after {
  content: "";
  display: block;
  width: 40px;
  height: 3px;
  background: var(--accent);
  margin-top: 12px;
  border-radius: 2px;
}

.more-link {
  font-size: 14px;
  color: var(--primary);
  display: inline-flex;
  align-items: center;
  gap: 4px;
}

.more-link:hover {
  color: var(--primary-light);
}

.more-link::after {
  content: "→";
  transition: transform var(--transition);
}

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

.section-header-actions {
  display: flex;
  align-items: center;
  gap: 16px;
  flex-wrap: wrap;
}

.btn-sm {
  padding: 8px 18px;
  font-size: 13px;
}

.directions-intro {
  font-size: 15px;
  color: var(--text-light);
  margin: -12px 0 32px;
}

.directions-grid-page {
  max-width: 960px;
  margin: 0 auto;
}

/* ========== News ========== */
.news-list {
  display: flex;
  flex-direction: column;
  gap: 0;
  background: #fff;
  border-radius: var(--radius);
  overflow: hidden;
  box-shadow: var(--shadow);
}

.news-item {
  display: flex;
  align-items: center;
  gap: 20px;
  padding: 20px 28px;
  border-bottom: 1px solid var(--border);
  transition: background var(--transition);
}

.news-item:last-child {
  border-bottom: none;
}

.news-item:hover {
  background: var(--bg-gray);
}

.news-date {
  flex-shrink: 0;
  width: 72px;
  text-align: center;
}

.news-date .day {
  font-size: 28px;
  font-weight: 700;
  color: var(--primary);
  line-height: 1;
  font-family: var(--font-en);
}

.news-date .ym {
  font-size: 12px;
  color: var(--text-muted);
  margin-top: 4px;
}

.news-body {
  flex: 1;
  min-width: 0;
}

.news-body h3 {
  font-size: 16px;
  font-weight: 500;
  color: var(--text);
  white-space: nowrap;
  overflow: hidden;
  text-overflow: ellipsis;
  transition: color var(--transition);
}

.news-item:hover .news-body h3 {
  color: var(--primary);
}

.news-tag {
  display: inline-block;
  padding: 2px 8px;
  font-size: 12px;
  color: var(--primary);
  background: rgba(26, 79, 139, 0.08);
  border-radius: 3px;
  margin-bottom: 6px;
}

/* News page grid */
.news-grid {
  display: grid;
  gap: 0;
  background: #fff;
  border-radius: var(--radius);
  box-shadow: var(--shadow);
  overflow: hidden;
}

.news-card {
  display: flex;
  flex-direction: column;
  gap: 0;
  padding: 0;
  border-bottom: 1px solid var(--border);
  transition: background var(--transition);
}

.news-card:last-child {
  border-bottom: none;
}

.news-card:hover {
  background: var(--bg-gray);
}

.news-card-date {
  flex-shrink: 0;
  width: 80px;
  text-align: center;
  padding-top: 4px;
}

.news-card-date .day {
  font-size: 32px;
  font-weight: 700;
  color: var(--primary);
  line-height: 1;
  font-family: var(--font-en);
}

.news-card-date .ym {
  font-size: 13px;
  color: var(--text-muted);
  margin-top: 4px;
}

.news-card-body h3 {
  font-size: 17px;
  font-weight: 600;
  margin-bottom: 8px;
  transition: color var(--transition);
}

.news-card:hover .news-card-body h3 {
  color: var(--primary);
}

.news-card-body p {
  font-size: 14px;
  color: var(--text-light);
  display: -webkit-box;
  -webkit-line-clamp: 2;
  -webkit-box-orient: vertical;
  overflow: hidden;
}

/* ========== Research directions ========== */
.directions-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(220px, 1fr));
  gap: 24px;
}

.direction-card {
  position: relative;
  border-radius: var(--radius);
  overflow: hidden;
  aspect-ratio: 3 / 4;
  box-shadow: var(--shadow);
  cursor: pointer;
}

a.direction-card-link {
  display: block;
  color: inherit;
  text-decoration: none;
}

a.direction-card-link:hover {
  box-shadow: var(--shadow-hover);
}

.direction-card .card-bg {
  position: absolute;
  inset: 0;
  background-size: cover;
  background-position: center;
  transition: transform 0.5s ease;
}

.direction-card .card-bg.has-photo {
  background-color: #1a2332;
}

.direction-card:hover .card-bg {
  transform: scale(1.08);
}

.direction-card .card-overlay {
  position: absolute;
  inset: 0;
  background: linear-gradient(
    to top,
    rgba(13, 52, 96, 0.9) 0%,
    rgba(13, 52, 96, 0.3) 50%,
    transparent 100%
  );
  display: flex;
  flex-direction: column;
  justify-content: flex-end;
  padding: 24px;
  color: #fff;
}

.direction-card h3 {
  font-size: 20px;
  font-weight: 600;
  margin-bottom: 6px;
}

.direction-card p {
  font-size: 13px;
  opacity: 0.85;
  max-height: 0;
  overflow: hidden;
  transition: max-height 0.4s ease, opacity 0.3s ease;
  opacity: 0;
}

.direction-card:hover p {
  max-height: 80px;
  opacity: 0.85;
}

/* ========== About ========== */
.about-grid {
  display: grid;
  grid-template-columns: 1.2fr 1fr;
  gap: 48px;
  align-items: center;
}

.about-text p {
  font-size: 15px;
  color: var(--text-light);
  margin-bottom: 16px;
  line-height: 1.9;
}

.stats-row {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 16px;
  margin-top: 36px;
}

.stat-item {
  text-align: center;
  padding: 20px 12px;
  background: var(--bg-gray);
  border-radius: var(--radius);
}

.stat-item .num {
  font-size: 32px;
  font-weight: 700;
  color: var(--primary);
  font-family: var(--font-en);
  line-height: 1.2;
}

.stat-item .num span {
  font-size: 18px;
  font-weight: 500;
}

.stat-item .label {
  font-size: 13px;
  color: var(--text-muted);
  margin-top: 6px;
}

.about-visual {
  position: relative;
  border-radius: var(--radius);
  overflow: hidden;
  aspect-ratio: 4 / 3;
  background: linear-gradient(135deg, var(--primary-dark), var(--primary-light));
  display: flex;
  align-items: center;
  justify-content: center;
  color: #fff;
  box-shadow: var(--shadow-hover);
}

.about-visual .play-btn {
  width: 72px;
  height: 72px;
  border-radius: 50%;
  background: rgba(255, 255, 255, 0.2);
  backdrop-filter: blur(4px);
  border: 2px solid rgba(255, 255, 255, 0.6);
  display: flex;
  align-items: center;
  justify-content: center;
  transition: all var(--transition);
}

.about-visual .play-btn:hover {
  background: rgba(255, 255, 255, 0.35);
  transform: scale(1.08);
}

.about-visual .play-btn svg {
  width: 28px;
  height: 28px;
  margin-left: 4px;
}

.about-visual .visual-label {
  position: absolute;
  bottom: 20px;
  left: 24px;
  font-size: 14px;
  opacity: 0.8;
}

.about-visual.has-photo {
  aspect-ratio: auto;
  background: #1a2332;
  padding: 0;
}

.about-visual.has-photo img {
  display: block;
  width: 100%;
  height: auto;
  object-fit: contain;
}

.about-visual.has-photo::before {
  content: "";
  position: absolute;
  inset: 0;
  background: linear-gradient(to top, rgba(13, 52, 96, 0.45), transparent 40%);
  pointer-events: none;
}

.about-visual.has-photo .visual-label {
  z-index: 1;
}

.team-avatar.has-photo,
.pi-avatar.has-photo {
  padding: 0;
}

.team-avatar.has-photo img,
.pi-avatar.has-photo img {
  width: 100%;
  height: 100%;
  object-fit: cover;
}

.item-card-img.has-photo {
  padding: 0;
}

.item-card-img.has-photo img {
  width: 100%;
  height: 100%;
  object-fit: cover;
}

.news-card.has-cover {
  flex-direction: column;
  gap: 0;
  padding: 0;
}

.news-card-cover {
  width: 100%;
  aspect-ratio: 21 / 9;
  overflow: hidden;
  background: #e8eef5;
}

.news-card-cover img {
  width: 100%;
  height: 100%;
  object-fit: cover;
}

.news-card-main {
  display: flex;
  gap: 24px;
  padding: 28px;
}

.article {
  max-width: 820px;
  margin: 0 auto;
  background: #fff;
  border-radius: var(--radius);
  box-shadow: var(--shadow);
  padding: 40px 44px;
}

.article-meta {
  display: flex;
  align-items: center;
  gap: 12px;
  margin-bottom: 16px;
  color: var(--text-muted);
  font-size: 13px;
}

.article-title {
  font-size: 28px;
  font-weight: 700;
  color: var(--primary-dark);
  line-height: 1.4;
  margin-bottom: 16px;
}

.article-summary {
  font-size: 15px;
  color: var(--text-light);
  line-height: 1.8;
  padding: 14px 16px;
  background: var(--bg-gray);
  border-left: 3px solid var(--accent);
  margin-bottom: 28px;
}

.article-cover {
  margin-bottom: 28px;
  border-radius: var(--radius);
  overflow: hidden;
}

.article-cover img {
  width: 100%;
  display: block;
}

.article-body {
  font-size: 16px;
  line-height: 1.9;
  color: var(--text);
}

.article-body p {
  margin-bottom: 1em;
}

.article-body h2,
.article-body h3 {
  margin: 1.4em 0 0.6em;
  color: var(--primary-dark);
}

.article-body img {
  max-width: 100%;
  height: auto;
  border-radius: 6px;
  margin: 1em 0;
}

.article-body ul,
.article-body ol {
  margin: 0 0 1em 1.4em;
  list-style: revert;
}

.article-body a {
  color: var(--primary);
  text-decoration: underline;
}

.article-back {
  margin-top: 36px;
  padding-top: 20px;
  border-top: 1px solid var(--border);
}

@media (max-width: 768px) {
  .article {
    padding: 24px 18px;
  }
  .article-title {
    font-size: 22px;
  }
  .news-card-main {
    padding: 18px;
    gap: 14px;
  }
}

/* ========== Page banner ========== */
.page-banner {
  margin-top: var(--header-h);
  padding: 56px 0;
  background: linear-gradient(135deg, var(--primary-dark), var(--primary));
  color: #fff;
  position: relative;
  overflow: hidden;
}

.page-banner::before {
  content: "";
  position: absolute;
  right: -60px;
  top: -60px;
  width: 300px;
  height: 300px;
  border-radius: 50%;
  background: rgba(255, 255, 255, 0.05);
}

.page-banner h1 {
  font-size: 32px;
  font-weight: 700;
  margin-bottom: 8px;
}

.breadcrumb {
  font-size: 13px;
  opacity: 0.75;
  display: flex;
  align-items: center;
  gap: 8px;
}

.breadcrumb a:hover {
  opacity: 1;
  text-decoration: underline;
}

/* ========== Team ========== */
.team-tabs {
  display: flex;
  gap: 8px;
  margin-bottom: 36px;
  flex-wrap: wrap;
}

.team-tab {
  padding: 8px 20px;
  font-size: 14px;
  border-radius: 20px;
  color: var(--text-light);
  background: var(--bg-gray);
  transition: all var(--transition);
  border: 1px solid transparent;
}

.team-tab:hover,
.team-tab.active {
  background: var(--primary);
  color: #fff;
}

.team-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(260px, 1fr));
  gap: 24px;
}

.team-card {
  background: #fff;
  border-radius: var(--radius);
  overflow: hidden;
  box-shadow: var(--shadow);
  transition: all var(--transition);
  text-align: center;
}

.team-card-link {
  display: block;
  color: inherit;
  text-decoration: none;
  cursor: pointer;
}

.team-card-link:hover {
  transform: translateY(-4px);
  box-shadow: var(--shadow-hover);
}

.team-card-link:hover .card-more,
.pi-card-link:hover .card-more {
  color: var(--primary-light);
}

.card-more {
  display: inline-block;
  margin-top: 12px;
  font-size: 13px;
  color: var(--primary);
  font-weight: 500;
}

.pi-card-link {
  display: grid;
  text-decoration: none;
  color: inherit;
  transition: box-shadow var(--transition), transform var(--transition);
}

.pi-card-link:hover {
  transform: translateY(-2px);
  box-shadow: var(--shadow-hover);
}

.alumni-list {
  background: #fff;
  border-radius: var(--radius);
  box-shadow: var(--shadow);
  overflow: hidden;
}

.alumni-row {
  display: grid;
  grid-template-columns: 140px 1fr auto;
  gap: 12px 20px;
  align-items: center;
  padding: 18px 24px;
  border-bottom: 1px solid var(--border);
  color: inherit;
  text-decoration: none;
  transition: background var(--transition);
}

.alumni-row:last-child {
  border-bottom: none;
}

.alumni-row:hover {
  background: var(--bg-gray);
}

.alumni-name {
  font-size: 16px;
  font-weight: 600;
  color: var(--primary-dark);
}

.alumni-dest {
  font-size: 14px;
  color: var(--text-light);
  line-height: 1.5;
}

.alumni-note {
  display: none;
}

.alumni-more {
  font-size: 13px;
  color: var(--primary);
  font-weight: 500;
  white-space: nowrap;
}

.alumni-row:hover .alumni-more {
  color: var(--primary-light);
}

.alumni-empty {
  padding: 28px 24px;
  text-align: center;
  color: var(--text-muted);
  font-size: 14px;
}

@media (max-width: 768px) {
  .alumni-row {
    grid-template-columns: 1fr auto;
    gap: 6px 12px;
  }
  .alumni-name {
    grid-column: 1;
  }
  .alumni-dest {
    grid-column: 1;
  }
  .alumni-more {
    grid-column: 2;
    grid-row: 1 / span 2;
    align-self: center;
  }
}

.member-profile {
  max-width: 900px;
  margin: 0 auto;
  background: #fff;
  border-radius: var(--radius);
  box-shadow: var(--shadow);
  padding: 36px 40px;
}

.member-profile-head {
  display: grid;
  grid-template-columns: 200px 1fr;
  gap: 32px;
  align-items: start;
  margin-bottom: 28px;
  padding-bottom: 28px;
  border-bottom: 1px solid var(--border);
}

.member-hero-photo {
  width: 200px;
  aspect-ratio: 3 / 4;
  border-radius: var(--radius);
  overflow: hidden;
  background: linear-gradient(145deg, #e8eef5, #d0dce8);
}

.member-hero-photo img {
  width: 100%;
  height: 100%;
  object-fit: cover;
}

.member-hero-photo.placeholder {
  display: flex;
  align-items: center;
  justify-content: center;
}

.member-hero-photo.placeholder span {
  font-size: 56px;
  font-weight: 700;
  color: var(--primary);
  opacity: 0.35;
}

.member-group {
  display: inline-block;
  font-size: 12px;
  color: var(--primary);
  background: rgba(26, 79, 139, 0.08);
  padding: 2px 10px;
  border-radius: 999px;
  margin-bottom: 10px;
}

.member-profile-meta h1 {
  font-size: 28px;
  color: var(--primary-dark);
  margin-bottom: 8px;
}

.member-title {
  font-size: 15px;
  color: var(--primary);
  margin-bottom: 12px;
}

.member-email {
  font-size: 14px;
  color: var(--text-light);
  font-family: var(--font-en);
}

.member-email:hover {
  color: var(--primary);
}

.member-profile-body {
  font-size: 15px;
  line-height: 1.9;
}

@media (max-width: 768px) {
  .member-profile {
    padding: 24px 18px;
  }
  .member-profile-head {
    grid-template-columns: 1fr;
    justify-items: center;
    text-align: center;
  }
  .member-hero-photo {
    width: 160px;
  }
}

.team-card:hover {
  transform: translateY(-4px);
  box-shadow: var(--shadow-hover);
}

.team-avatar {
  width: 100%;
  aspect-ratio: 1;
  background: linear-gradient(145deg, #e8eef5, #d0dce8);
  display: flex;
  align-items: center;
  justify-content: center;
  position: relative;
  overflow: hidden;
}

.team-avatar .initials {
  font-size: 48px;
  font-weight: 700;
  color: var(--primary);
  opacity: 0.4;
  font-family: var(--font-en);
}

.team-info {
  padding: 20px 16px 24px;
}

.team-info h3 {
  font-size: 18px;
  font-weight: 600;
  margin-bottom: 4px;
}

.team-info .title {
  font-size: 13px;
  color: var(--primary);
  margin-bottom: 8px;
}

.team-info .email {
  font-size: 12px;
  color: var(--text-muted);
  font-family: var(--font-en);
  word-break: break-all;
}

.team-info .bio {
  font-size: 13px;
  color: var(--text-light);
  margin-top: 10px;
  text-align: left;
  line-height: 1.6;
  display: -webkit-box;
  -webkit-line-clamp: 3;
  -webkit-box-orient: vertical;
  overflow: hidden;
}

/* Featured PI card */
.pi-card {
  display: grid;
  grid-template-columns: 220px 1fr;
  gap: 36px;
  background: #fff;
  border-radius: var(--radius);
  padding: 36px;
  box-shadow: var(--shadow);
  margin-bottom: 40px;
  align-items: start;
}

.pi-avatar {
  width: 220px;
  aspect-ratio: 3 / 4;
  border-radius: var(--radius);
  background: linear-gradient(145deg, #e8eef5, #d0dce8);
  display: flex;
  align-items: center;
  justify-content: center;
  overflow: hidden;
}

.pi-avatar .initials {
  font-size: 64px;
  font-weight: 700;
  color: var(--primary);
  opacity: 0.35;
}

.pi-detail h2 {
  font-size: 24px;
  font-weight: 700;
  margin-bottom: 4px;
}

.pi-detail .pi-title {
  font-size: 15px;
  color: var(--primary);
  margin-bottom: 16px;
}

.pi-detail .pi-meta {
  font-size: 13px;
  color: var(--text-muted);
  margin-bottom: 16px;
  font-family: var(--font-en);
}

.pi-detail p {
  font-size: 14px;
  color: var(--text-light);
  line-height: 1.9;
  margin-bottom: 12px;
}

/* ========== Research / Publications ========== */
.year-filter {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
  margin-bottom: 32px;
}

.year-btn {
  padding: 6px 16px;
  font-size: 13px;
  border-radius: 4px;
  color: var(--text-light);
  background: var(--bg-gray);
  border: 1px solid var(--border);
  transition: all var(--transition);
}

.year-btn:hover,
.year-btn.active {
  background: var(--primary);
  color: #fff;
  border-color: var(--primary);
}

.pub-list {
  display: flex;
  flex-direction: column;
  gap: 0;
}

.pub-item {
  padding: 24px 0;
  border-bottom: 1px solid var(--border);
  display: flex;
  gap: 16px;
}

a.pub-item-link {
  color: inherit;
  text-decoration: none;
  transition: background var(--transition);
  margin: 0 -12px;
  padding-left: 12px;
  padding-right: 12px;
  border-radius: 8px;
}

a.pub-item-link:hover {
  background: rgba(26, 79, 139, 0.04);
}

a.pub-item-link:hover .pub-title-zh {
  color: var(--primary);
}

.pub-item:first-child {
  padding-top: 0;
}

a.pub-item-link:first-child {
  padding-top: 12px;
}

.pub-num {
  flex-shrink: 0;
  width: 36px;
  height: 36px;
  background: var(--bg-gray);
  border-radius: 50%;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 13px;
  font-weight: 600;
  color: var(--primary);
  font-family: var(--font-en);
  margin-top: 2px;
}

.pub-content .pub-title-zh {
  font-size: 18px;
  font-weight: 700;
  line-height: 1.45;
  color: var(--primary-dark);
  margin: 0 0 6px;
  letter-spacing: 0.02em;
}

.pub-content .pub-title-en {
  font-size: 14px;
  line-height: 1.55;
  color: var(--text-light);
  font-family: var(--font-en);
  margin-bottom: 10px;
}

.pub-content .pub-meta {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 8px;
  font-size: 13px;
}

.pub-content .pub-journal {
  color: var(--primary);
  font-style: italic;
}

.pub-title-link {
  color: inherit;
  text-decoration: none;
  transition: color var(--transition);
}

.pub-title-link:hover {
  color: var(--primary);
}

.pub-link-btn {
  display: inline-flex;
  align-items: center;
  margin-top: 10px;
  font-size: 13px;
  font-weight: 500;
  color: var(--primary);
  padding: 4px 0;
}

.pub-link-btn:hover {
  color: var(--primary-light);
  text-decoration: underline;
}

.pub-badge {
  display: inline-block;
  padding: 2px 8px;
  font-size: 11px;
  font-weight: 600;
  color: #fff;
  background: var(--accent);
  border-radius: 3px;
  vertical-align: middle;
  font-style: normal;
}

/* ========== Products / Equipment grid ========== */
.card-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(280px, 1fr));
  gap: 24px;
}

.item-card {
  background: #fff;
  border-radius: var(--radius);
  overflow: hidden;
  box-shadow: var(--shadow);
  transition: all var(--transition);
}

.item-card:hover {
  transform: translateY(-4px);
  box-shadow: var(--shadow-hover);
}

a.item-card-link {
  display: block;
  color: inherit;
  text-decoration: none;
  cursor: pointer;
}

a.item-card-link .card-more {
  display: inline-block;
  margin-top: 12px;
  font-size: 13px;
  color: var(--primary);
}

.item-card-img {
  aspect-ratio: 16 / 10;
  background: linear-gradient(135deg, #e8eef5, #c5d4e8);
  display: flex;
  align-items: center;
  justify-content: center;
  position: relative;
  overflow: hidden;
}

.item-card-img .icon-placeholder {
  width: 56px;
  height: 56px;
  opacity: 0.35;
  color: var(--primary);
}

.item-card-body {
  padding: 20px;
}

.item-card-body h3 {
  font-size: 16px;
  font-weight: 600;
  margin-bottom: 8px;
  transition: color var(--transition);
}

.item-card:hover .item-card-body h3 {
  color: var(--primary);
}

.item-card-body p {
  font-size: 13px;
  color: var(--text-light);
  line-height: 1.6;
}

.item-card-body .spec {
  font-size: 12px;
  color: var(--text-muted);
  margin-top: 8px;
  font-family: var(--font-en);
}

/* ========== Contact ========== */
.contact-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 24px;
  margin-bottom: 48px;
}

.contact-card {
  background: #fff;
  border-radius: var(--radius);
  padding: 36px 28px;
  text-align: center;
  box-shadow: var(--shadow);
  transition: all var(--transition);
}

.contact-card:hover {
  transform: translateY(-3px);
  box-shadow: var(--shadow-hover);
}

.contact-icon {
  width: 56px;
  height: 56px;
  margin: 0 auto 16px;
  background: rgba(26, 79, 139, 0.08);
  border-radius: 50%;
  display: flex;
  align-items: center;
  justify-content: center;
  color: var(--primary);
}

.contact-icon svg {
  width: 24px;
  height: 24px;
}

.contact-card h3 {
  font-size: 16px;
  font-weight: 600;
  margin-bottom: 10px;
  color: var(--primary-dark);
}

.contact-card p {
  font-size: 14px;
  color: var(--text-light);
  line-height: 1.7;
}

.map-box {
  width: 100%;
  border-radius: var(--radius);
  overflow: hidden;
  box-shadow: var(--shadow);
  background: #fff;
  border: 1px solid var(--border);
}

.map-frame {
  display: block;
  width: 100%;
  height: 480px;
  border: 0;
  background: #e8eef5;
}

.map-caption {
  display: flex;
  justify-content: space-between;
  align-items: center;
  gap: 12px;
  flex-wrap: wrap;
  padding: 14px 18px;
  font-size: 13px;
  color: var(--text-light);
  background: #fff;
  border-top: 1px solid var(--border);
}

.map-links {
  display: flex;
  gap: 16px;
}

.map-links a {
  color: var(--primary);
  font-weight: 500;
}

.map-links a:hover {
  text-decoration: underline;
}

.contact-form-panel {
  margin-top: 40px;
  margin-bottom: 40px;
  background: #fff;
  border: 1px solid var(--border);
  border-radius: var(--radius);
  box-shadow: var(--shadow);
  padding: 32px;
}

.contact-form-desc {
  color: var(--text-light);
  font-size: 14px;
  margin: -8px 0 24px;
}

.contact-form .field {
  margin-bottom: 16px;
}

.contact-form label {
  display: block;
  font-size: 13px;
  color: var(--text-light);
  margin-bottom: 6px;
}

.contact-form label span {
  color: #c0392b;
}

.contact-form input,
.contact-form textarea {
  width: 100%;
  padding: 12px 14px;
  border: 1px solid var(--border);
  border-radius: 8px;
  font: inherit;
  color: var(--text);
  background: #fff;
  transition: border-color var(--transition), box-shadow var(--transition);
}

.contact-form input:focus,
.contact-form textarea:focus {
  outline: none;
  border-color: var(--primary);
  box-shadow: 0 0 0 3px rgba(26, 79, 139, 0.12);
}

.contact-form-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 16px;
}

.contact-form-actions {
  display: flex;
  align-items: center;
  gap: 16px;
  flex-wrap: wrap;
  margin-top: 8px;
}

.contact-form-status {
  font-size: 13px;
  color: var(--text-muted);
}

.contact-form-status.ok {
  color: #1e7a46;
}

.contact-form-status.err {
  color: #c0392b;
}

@media (max-width: 768px) {
  .contact-form-grid {
    grid-template-columns: 1fr;
  }
  .contact-form-panel {
    padding: 22px 18px;
  }
}

.map-placeholder {
  width: 100%;
  height: 360px;
  background: linear-gradient(135deg, #e8eef5, #d0dce8);
  border-radius: var(--radius);
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  color: var(--text-muted);
  gap: 12px;
  box-shadow: var(--shadow);
}

.map-placeholder svg {
  width: 48px;
  height: 48px;
  opacity: 0.4;
}

/* ========== Footer ========== */
.site-footer {
  background: var(--bg-dark);
  color: rgba(255, 255, 255, 0.7);
  padding: 56px 0 0;
  margin-top: auto;
}

.footer-grid {
  display: grid;
  grid-template-columns: 1.5fr 1fr 1fr;
  gap: 40px;
  padding-bottom: 40px;
  border-bottom: 1px solid rgba(255, 255, 255, 0.1);
}

.footer-brand .logo-mark {
  margin-bottom: 16px;
}

.footer-brand p {
  font-size: 13px;
  line-height: 1.8;
  margin-top: 12px;
  max-width: 320px;
}

.footer-col h4 {
  font-size: 15px;
  font-weight: 600;
  color: #fff;
  margin-bottom: 16px;
}

.footer-col ul li {
  margin-bottom: 10px;
}

.footer-col a {
  font-size: 13px;
  transition: color var(--transition);
}

.footer-col a:hover {
  color: #fff;
}

.footer-bottom {
  padding: 20px 0;
  display: flex;
  justify-content: space-between;
  align-items: center;
  font-size: 12px;
  opacity: 0.6;
}

/* ========== Pagination ========== */
.pagination {
  display: flex;
  justify-content: center;
  gap: 8px;
  margin-top: 40px;
}

.pagination a,
.pagination span {
  width: 36px;
  height: 36px;
  display: flex;
  align-items: center;
  justify-content: center;
  border-radius: 6px;
  font-size: 14px;
  color: var(--text-light);
  background: var(--bg-gray);
  transition: all var(--transition);
}

.pagination a:hover,
.pagination span.active {
  background: var(--primary);
  color: #fff;
}

/* ========== Utilities ========== */
.main-content {
  flex: 1;
}

.sr-only {
  position: absolute;
  width: 1px;
  height: 1px;
  padding: 0;
  margin: -1px;
  overflow: hidden;
  clip: rect(0, 0, 0, 0);
  border: 0;
}

/* Direction card backgrounds */
.dir-bg-1 {
  background: linear-gradient(145deg, #1a4f8b, #3a7bc8);
}
.dir-bg-2 {
  background: linear-gradient(145deg, #0d5c4d, #2a9d8f);
}
.dir-bg-3 {
  background: linear-gradient(145deg, #5c3a1a, #c4783a);
}
.dir-bg-4 {
  background: linear-gradient(145deg, #3a1a5c, #7b3a9d);
}

/* ========== Responsive ========== */
@media (max-width: 1024px) {
  .directions-grid {
    grid-template-columns: repeat(2, 1fr);
  }

  .about-grid {
    grid-template-columns: 1fr;
    gap: 32px;
  }

  .pi-card {
    grid-template-columns: 160px 1fr;
    gap: 24px;
    padding: 24px;
  }

  .pi-avatar {
    width: 160px;
  }

  .contact-grid {
    grid-template-columns: 1fr;
  }

  .footer-grid {
    grid-template-columns: 1fr 1fr;
  }
}

@media (max-width: 768px) {
  :root {
    --header-h: 64px;
  }

  .menu-toggle {
    display: flex;
  }

  .nav-main {
    position: fixed;
    top: 0;
    right: -100%;
    width: 280px;
    height: 100vh;
    background: #fff;
    flex-direction: column;
    align-items: stretch;
    padding: 80px 24px 24px;
    gap: 4px;
    box-shadow: -4px 0 24px rgba(0, 0, 0, 0.1);
    transition: right var(--transition);
    z-index: 999;
  }

  .nav-main.open {
    right: 0;
  }

  .nav-main a {
    padding: 14px 16px;
    font-size: 16px;
    border-radius: 8px;
  }

  .nav-main a.active::after {
    display: none;
  }

  .nav-main a.active {
    background: rgba(26, 79, 139, 0.08);
  }

  .nav-overlay {
    display: none;
    position: fixed;
    inset: 0;
    background: rgba(0, 0, 0, 0.4);
    z-index: 998;
  }

  .nav-overlay.open {
    display: block;
  }

  .hero {
    height: 360px;
  }

  .hero-content h1 {
    font-size: 28px;
  }

  .hero-content p {
    font-size: 15px;
  }

  .section {
    padding: 48px 0;
  }

  .section-header {
    flex-direction: column;
    align-items: flex-start;
    gap: 12px;
  }

  .section-title h2 {
    font-size: 22px;
  }

  .directions-grid {
    grid-template-columns: 1fr 1fr;
    gap: 12px;
  }

  .stats-row {
    grid-template-columns: repeat(2, 1fr);
  }

  .pi-card {
    grid-template-columns: 1fr;
    text-align: center;
  }

  .pi-avatar {
    width: 140px;
    margin: 0 auto;
  }

  .news-item {
    padding: 16px 20px;
    gap: 14px;
  }

  .news-body h3 {
    white-space: normal;
    display: -webkit-box;
    -webkit-line-clamp: 2;
    -webkit-box-orient: vertical;
  }

  .footer-grid {
    grid-template-columns: 1fr;
    gap: 28px;
  }

  .footer-bottom {
    flex-direction: column;
    gap: 8px;
    text-align: center;
  }

  .lang-switch {
    display: none;
  }
}

@media (max-width: 480px) {
  .directions-grid {
    grid-template-columns: 1fr;
  }

  .direction-card {
    aspect-ratio: 16 / 9;
  }

  .hero-content h1 {
    font-size: 24px;
  }
}