:root {
  --pku-red: #8c000b;
  --pku-red-deep: #5d0008;
  --carbon: #202427;
  --ink: #171b1d;
  --muted: #687074;
  --paper: #f4f2ec;
  --white: #fff;
  --line: rgba(23, 27, 29, 0.12);
  --line-light: rgba(255, 255, 255, 0.18);
  --green: #8fbd83;
  --teal: #2f8c8c;
  --gold: #d1a33c;
  --shadow: 0 28px 80px rgba(18, 24, 28, 0.18);
  --header-height: 92px;
}

* {
  box-sizing: border-box;
}

html {
  scroll-behavior: smooth;
}

body {
  margin: 0;
  color: var(--ink);
  background: var(--paper);
  font-family: "Microsoft YaHei", "PingFang SC", "Noto Sans SC", Arial, sans-serif;
  line-height: 1.7;
  overflow-x: hidden;
}

body.nav-open {
  overflow: hidden;
}

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

a,
button {
  font: inherit;
}

button {
  cursor: pointer;
}

.scroll-progress {
  position: fixed;
  inset: 0 auto auto 0;
  z-index: 90;
  width: 100%;
  height: 3px;
  transform: scaleX(0);
  transform-origin: left;
  background: linear-gradient(90deg, var(--pku-red), var(--gold), var(--teal));
}

.site-header {
  position: fixed;
  top: 24px;
  left: 50%;
  z-index: 80;
  display: grid;
  grid-template-columns: minmax(390px, 1fr) minmax(640px, auto) minmax(390px, 1fr);
  width: min(1480px, calc(100% - 56px));
  min-height: 96px;
  align-items: stretch;
  overflow: visible;
  color: var(--white);
  background:
    linear-gradient(90deg, rgba(18, 20, 27, 0.58), rgba(39, 42, 50, 0.42) 52%, rgba(18, 22, 30, 0.34)),
    rgba(255, 255, 255, 0.08);
  border-top: 0;
  border-bottom: 1px solid rgba(255, 255, 255, 0.2);
  border-radius: 0 0 18px 18px;
  box-shadow: 0 16px 50px rgba(0, 0, 0, 0.2);
  transform: translate(-50%, -130%);
  opacity: 0;
  backdrop-filter: blur(16px) saturate(1.35);
  transition:
    top 520ms cubic-bezier(0.22, 1, 0.36, 1),
    width 520ms cubic-bezier(0.22, 1, 0.36, 1),
    border-radius 520ms cubic-bezier(0.22, 1, 0.36, 1),
    background 320ms ease,
    color 320ms ease,
    border-color 320ms ease,
    transform 720ms cubic-bezier(0.22, 1, 0.36, 1),
    opacity 520ms ease;
}

.site-header::before {
  content: "";
  position: absolute;
  inset: 0;
  z-index: -1;
  border-radius: inherit;
  background: inherit;
  pointer-events: none;
}

body.nav-ready .site-header {
  transform: translate(-50%, 0);
  opacity: 1;
}

.site-header.is-docked {
  top: 0;
  width: 100%;
  grid-template-columns: minmax(390px, 1fr) minmax(640px, auto) minmax(390px, 1fr);
  color: var(--ink);
  border-left: 0;
  border-right: 0;
  border-radius: 0;
  border-bottom-color: rgba(23, 27, 29, 0.12);
  background: var(--white);
  box-shadow: 0 12px 36px rgba(18, 24, 28, 0.1);
  backdrop-filter: none;
}

.brand {
  display: flex;
  align-items: center;
  gap: 14px;
  justify-self: center;
  min-width: 0;
  padding: 18px clamp(22px, 3vw, 42px);
  color: inherit;
  text-decoration: none;
  background: transparent;
}

.brand-emblem {
  display: grid;
  flex: 0 0 58px;
  width: 58px;
  height: 58px;
  place-items: center;
  border-radius: 50%;
  overflow: hidden;
  background: rgba(255, 255, 255, 0.9);
  box-shadow: 0 0 0 1px rgba(255, 255, 255, 0.5);
}

.brand-emblem img {
  width: 100%;
  height: 100%;
  object-fit: cover;
}

.brand-copy {
  min-width: 0;
}

.brand-copy strong,
.brand-copy small {
  display: block;
  line-height: 1.25;
}

.brand-copy strong {
  font-size: clamp(17px, 1.4vw, 22px);
  white-space: nowrap;
}

.brand-copy small {
  margin-top: 4px;
  color: rgba(255, 255, 255, 0.74);
  font-size: 12px;
  white-space: nowrap;
}

.site-header.is-docked .brand-copy small {
  color: var(--muted);
}

.site-header.is-docked .brand-emblem {
  background: var(--white);
  box-shadow: 0 0 0 1px rgba(23, 27, 29, 0.12);
}

.site-nav {
  display: flex;
  align-items: stretch;
  justify-content: center;
  justify-self: center;
  width: max-content;
}

.site-nav a {
  position: relative;
  display: grid;
  min-width: 100px;
  place-items: center;
  padding: 0 18px;
  color: rgba(255, 255, 255, 0.9);
  border-left: 0;
  text-decoration: none;
  font-size: 17px;
  font-weight: 800;
  transition: background 220ms ease, color 220ms ease, box-shadow 220ms ease;
}

.site-header.is-docked .site-nav a {
  color: rgba(17, 20, 22, 0.94);
}

.site-nav a::after {
  content: "";
  position: absolute;
  left: 28px;
  right: 28px;
  bottom: 20px;
  height: 3px;
  transform: scaleX(0);
  transform-origin: center;
  background: rgba(255, 255, 255, 0.86);
  transition: transform 220ms ease;
}

.site-header.is-docked .site-nav a::after {
  background: var(--ink);
}

.site-nav a:hover,
.site-nav a.is-active {
  color: var(--white);
  background:
    linear-gradient(180deg, rgba(255, 255, 255, 0.08), rgba(255, 255, 255, 0.03)),
    rgba(20, 18, 24, 0.42);
  box-shadow: inset 0 -34px 46px rgba(0, 0, 0, 0.2);
}

.site-header.is-docked .site-nav a:hover,
.site-header.is-docked .site-nav a.is-active {
  color: var(--ink);
  background: rgba(23, 27, 29, 0.04);
  box-shadow: none;
}

.site-nav a:hover::after,
.site-nav a.is-active::after,
.member-nav-trigger.is-active::after,
.nav-member:hover .member-nav-trigger::after {
  transform: scaleX(1);
}

body.is-cover .site-nav a.is-active:not(:hover) {
  color: rgba(255, 255, 255, 0.9);
  background: transparent;
  box-shadow: none;
}

body.is-cover .site-nav a.is-active:not(:hover)::after {
  transform: scaleX(0);
}

.nav-member {
  position: relative;
  display: grid;
  align-items: stretch;
  --member-menu-line: #fff;
}

.nav-member .member-nav-trigger {
  height: 100%;
}

.nav-member::before {
  content: "";
  position: absolute;
  left: 50%;
  bottom: 0;
  z-index: 4;
  width: 3px;
  height: 23px;
  background: var(--member-menu-line);
  opacity: 0;
  transform: translateX(-50%) scaleY(0);
  transform-origin: top;
  transition: opacity 220ms ease, transform 260ms ease;
}

.nav-member .member-nav-trigger::after {
  z-index: 5;
  background: var(--member-menu-line);
}

.site-header.is-docked .nav-member::before {
  background: var(--member-menu-line);
}

.site-header.is-docked .nav-member {
  --member-menu-line: var(--ink);
}

.nav-member:hover::before {
  opacity: 1;
  transform: translateX(-50%) scaleY(1);
}

.nav-member::after {
  content: "";
  position: absolute;
  left: 50%;
  top: 100%;
  z-index: 3;
  width: 560px;
  height: 6px;
  opacity: 0;
  pointer-events: none;
  transform: translateX(-50%);
}

.nav-member:hover::after {
  pointer-events: auto;
}

.member-dropdown {
  position: absolute;
  top: 100%;
  left: 50%;
  z-index: 120;
  display: grid;
  grid-template-columns: repeat(4, minmax(92px, 1fr));
  min-width: 520px;
  padding: 12px 18px;
  border: 1px solid rgba(255, 255, 255, 0.24);
  border-radius: 6px;
  background:
    linear-gradient(90deg, rgba(255, 255, 255, 0.88), rgba(255, 255, 255, 0.76)),
    url("./assets/lab-hero.webp") center / cover;
  box-shadow: 0 22px 70px rgba(18, 24, 28, 0.2);
  opacity: 0;
  pointer-events: none;
  transform: translate(-50%, 12px);
  transition: opacity 220ms ease, transform 260ms cubic-bezier(0.22, 1, 0.36, 1);
  backdrop-filter: blur(16px) saturate(1.15);
}

.member-dropdown::before {
  content: "";
  position: absolute;
  top: -3px;
  left: -1px;
  right: -1px;
  z-index: 4;
  height: 3px;
  border-radius: 3px;
  background: var(--member-menu-line);
  pointer-events: none;
}

.site-header.is-docked .member-dropdown::before {
  background: var(--member-menu-line);
}

.member-dropdown::after {
  content: "";
  position: absolute;
  inset: auto 0 0;
  height: 44%;
  background:
    radial-gradient(circle at 16% 100%, rgba(140, 0, 11, 0.08), transparent 32%),
    linear-gradient(0deg, rgba(244, 242, 236, 0.92), transparent);
  pointer-events: none;
}

.nav-member:hover .member-dropdown {
  opacity: 1;
  pointer-events: auto;
  transform: translate(-50%, 0);
}

.member-dropdown button {
  position: relative;
  z-index: 1;
  min-height: 54px;
  border: 0;
  color: var(--ink);
  background: transparent;
  font-size: 19px;
  font-weight: 900;
  transition: color 180ms ease, background 180ms ease;
}

.member-dropdown button:hover,
.member-dropdown button.is-active {
  color: var(--pku-red);
  background: rgba(140, 0, 11, 0.06);
}

.nav-achievement,
.nav-news {
  position: relative;
  display: grid;
  align-items: stretch;
  --achievement-menu-line: #fff;
}

.nav-achievement .achievement-nav-trigger,
.nav-news .news-nav-trigger {
  height: 100%;
}

.nav-achievement::before,
.nav-news::before {
  content: "";
  position: absolute;
  left: 50%;
  bottom: 0;
  z-index: 4;
  width: 3px;
  height: 23px;
  background: var(--achievement-menu-line);
  opacity: 0;
  transform: translateX(-50%) scaleY(0);
  transform-origin: top;
  transition: opacity 220ms ease, transform 260ms ease;
}

.nav-achievement .achievement-nav-trigger::after,
.nav-news .news-nav-trigger::after {
  z-index: 5;
  background: var(--achievement-menu-line);
}

.site-header.is-docked .nav-achievement,
.site-header.is-docked .nav-news {
  --achievement-menu-line: var(--ink);
}

.nav-achievement:hover::before,
.nav-news:hover::before {
  opacity: 1;
  transform: translateX(-50%) scaleY(1);
}

.nav-achievement::after,
.nav-news::after {
  content: "";
  position: absolute;
  left: 50%;
  top: 100%;
  z-index: 3;
  width: 480px;
  height: 6px;
  opacity: 0;
  pointer-events: none;
  transform: translateX(-50%);
}

.nav-achievement:hover::after,
.nav-news:hover::after {
  pointer-events: auto;
}

.achievement-dropdown,
.news-dropdown {
  position: absolute;
  top: 100%;
  left: 50%;
  z-index: 120;
  display: grid;
  grid-template-columns: repeat(2, minmax(120px, 1fr));
  min-width: 380px;
  padding: 12px 18px;
  border: 1px solid rgba(255, 255, 255, 0.24);
  border-radius: 6px;
  background:
    linear-gradient(90deg, rgba(255, 255, 255, 0.9), rgba(255, 255, 255, 0.76)),
    url("./assets/lab-hero.webp") center 58% / cover;
  box-shadow: 0 22px 70px rgba(18, 24, 28, 0.2);
  opacity: 0;
  pointer-events: none;
  transform: translate(-50%, 12px);
  transition: opacity 220ms ease, transform 260ms cubic-bezier(0.22, 1, 0.36, 1);
  backdrop-filter: blur(16px) saturate(1.15);
}

.achievement-dropdown {
  grid-template-columns: repeat(3, minmax(118px, 1fr));
  min-width: 480px;
}

.achievement-dropdown::before,
.news-dropdown::before {
  content: "";
  position: absolute;
  top: -3px;
  left: -1px;
  right: -1px;
  z-index: 4;
  height: 3px;
  border-radius: 3px;
  background: var(--achievement-menu-line);
  pointer-events: none;
}

.achievement-dropdown::after,
.news-dropdown::after {
  content: "";
  position: absolute;
  inset: auto 0 0;
  height: 44%;
  background:
    radial-gradient(circle at 86% 100%, rgba(47, 140, 140, 0.08), transparent 34%),
    linear-gradient(0deg, rgba(244, 242, 236, 0.92), transparent);
  pointer-events: none;
}

.nav-achievement:hover .achievement-dropdown,
.nav-news:hover .news-dropdown {
  opacity: 1;
  pointer-events: auto;
  transform: translate(-50%, 0);
}

.achievement-dropdown button,
.news-dropdown button {
  position: relative;
  z-index: 1;
  min-height: 54px;
  border: 0;
  color: var(--ink);
  background: transparent;
  font-size: 19px;
  font-weight: 900;
  transition: color 180ms ease, background 180ms ease;
}

.achievement-dropdown button:hover,
.achievement-dropdown button.is-active,
.news-dropdown button:hover,
.news-dropdown button.is-active {
  color: var(--pku-red);
  background: rgba(140, 0, 11, 0.06);
}

.achievement-nav-trigger.is-active::after,
.nav-achievement:hover .achievement-nav-trigger::after,
.news-nav-trigger.is-active::after,
.nav-news:hover .news-nav-trigger::after {
  transform: scaleX(1);
}

.header-tools {
  display: flex;
  align-items: center;
  justify-self: center;
  gap: 12px;
}

.lang-switch,
.school-link {
  display: inline-flex;
  height: 42px;
  align-items: center;
  justify-content: center;
  color: var(--white);
  font-weight: 800;
}

.lang-switch span {
  display: inline-flex;
  opacity: 0.56;
  transition: opacity 180ms ease, color 180ms ease;
}

.lang-switch {
  min-width: auto;
  padding: 0 14px;
  border: 1px solid rgba(255, 255, 255, 0.52);
  border-radius: 999px;
  background: rgba(255, 255, 255, 0.08);
  transition: background 180ms ease, border-color 180ms ease;
}

.school-link {
  min-width: 92px;
  padding: 0 16px;
  border: 1px solid rgba(255, 255, 255, 0.42);
  border-radius: 999px;
  background: rgba(255, 255, 255, 0.07);
  text-decoration: none;
  transition: background 180ms ease, border-color 180ms ease, color 180ms ease;
}

.school-link::after {
  content: "";
  display: inline-block;
  width: 0.95em;
  height: 0.95em;
  margin-left: 6px;
  background: currentColor;
  transform: translateY(1px) rotate(-45deg);
  mask: url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' viewBox='0 0 24 24' fill='none' stroke='black' stroke-width='2.8' stroke-linecap='round' stroke-linejoin='round'%3E%3Cpath d='M9 17H7A5 5 0 0 1 7 7h2'/%3E%3Cpath d='M15 7h2a5 5 0 1 1 0 10h-2'/%3E%3Cpath d='M8 12h8'/%3E%3C/svg%3E") center / contain no-repeat;
  -webkit-mask: url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' viewBox='0 0 24 24' fill='none' stroke='black' stroke-width='2.8' stroke-linecap='round' stroke-linejoin='round'%3E%3Cpath d='M9 17H7A5 5 0 0 1 7 7h2'/%3E%3Cpath d='M15 7h2a5 5 0 1 1 0 10h-2'/%3E%3Cpath d='M8 12h8'/%3E%3C/svg%3E") center / contain no-repeat;
}

.site-header.is-docked .lang-switch {
  color: var(--ink);
  border-color: rgba(23, 27, 29, 0.42);
  background: rgba(23, 27, 29, 0.03);
}

.site-header.is-docked .school-link {
  color: var(--ink);
  border-color: rgba(23, 27, 29, 0.28);
  background: rgba(23, 27, 29, 0.02);
}

.site-header.is-docked .lang-switch span {
  color: var(--ink);
}

.lang-switch:hover,
.school-link:hover {
  background: rgba(255, 255, 255, 0.15);
  border-color: rgba(255, 255, 255, 0.78);
}

.site-header.is-docked .lang-switch:hover,
.site-header.is-docked .school-link:hover {
  background: rgba(23, 27, 29, 0.07);
  border-color: rgba(23, 27, 29, 0.68);
}

.lang-switch i {
  margin: 0 8px;
  color: rgba(255, 255, 255, 0.38);
  font-style: normal;
}

.site-header.is-docked .lang-switch i {
  color: rgba(23, 27, 29, 0.32);
}

body:not(.is-en) [data-lang-zh],
body.is-en [data-lang-en] {
  color: var(--white);
  opacity: 1;
}

.nav-toggle {
  display: none;
  width: 52px;
  border: 0;
  border-left: 1px solid rgba(255, 255, 255, 0.16);
  color: var(--white);
  background: transparent;
}

.site-header.is-docked .nav-toggle {
  color: var(--ink);
  border-left-color: rgba(23, 27, 29, 0.12);
}

.nav-toggle span {
  display: block;
  width: 22px;
  height: 2px;
  margin: 6px auto;
  background: currentColor;
}

.cover {
  position: relative;
  min-height: 100vh;
  display: grid;
  align-items: center;
  overflow: hidden;
  color: var(--white);
  background: var(--carbon);
}

body:not(.is-cover) .cover {
  min-height: 0;
  height: 0;
  overflow: hidden;
}

.cover-image {
  position: absolute;
  inset: 0;
  width: 100%;
  height: 108%;
  object-fit: cover;
  filter: saturate(0.9) contrast(1.05);
}

.cover-overlay {
  position: absolute;
  inset: 0;
  background:
    radial-gradient(circle at 76% 32%, rgba(47, 140, 140, 0.3), transparent 34%),
    linear-gradient(90deg, rgba(78, 0, 7, 0.86), rgba(78, 0, 7, 0.5) 42%, rgba(17, 20, 22, 0.22)),
    linear-gradient(0deg, rgba(12, 14, 15, 0.7), rgba(12, 14, 15, 0.08));
}

.cover-content {
  position: relative;
  width: min(1180px, calc(100% - 48px));
  margin: 0 auto;
  padding-top: 96px;
  text-align: center;
}

.section-label,
.page-title p,
.block-title p {
  margin: 0 0 14px;
  color: var(--gold);
  font-size: 14px;
  font-weight: 900;
  letter-spacing: 0.08em;
  text-transform: uppercase;
}

.cover h1 {
  margin: 0;
  white-space: nowrap;
  font-size: clamp(42px, 6.2vw, 94px);
  line-height: 1.04;
  letter-spacing: 0;
}

.cover-lede {
  max-width: none;
  margin: 22px 0 0;
  color: rgba(255, 255, 255, 0.88);
  font-size: clamp(20px, 2.4vw, 34px);
  font-weight: 500;
  line-height: 1.3;
  white-space: nowrap;
}

.cover-pi {
  display: inline-flex;
  margin: 24px 0 0;
  padding: 8px 14px;
  color: rgba(255, 255, 255, 0.82);
  background: rgba(255, 255, 255, 0.08);
  border: 1px solid rgba(255, 255, 255, 0.18);
  border-radius: 4px;
  font-size: clamp(15px, 1.25vw, 18px);
  letter-spacing: 0;
  backdrop-filter: blur(12px);
}

.join-panel a {
  display: inline-flex;
  min-height: 48px;
  align-items: center;
  gap: 18px;
  padding: 12px 20px 12px 24px;
  color: var(--white);
  background: var(--pku-red);
  border: 1px solid rgba(255, 255, 255, 0.16);
  border-radius: 4px;
  font-weight: 900;
  text-decoration: none;
  transition: transform 220ms ease, background 220ms ease;
}

.join-panel a:hover {
  transform: translateY(-3px);
  background: var(--pku-red-deep);
}

.scroll-cue {
  position: absolute;
  left: 50%;
  bottom: 30px;
  display: grid;
  gap: 10px;
  place-items: center;
  border: 0;
  color: rgba(255, 255, 255, 0.78);
  background: transparent;
  transform: translateX(-50%);
}

.scroll-cue span {
  font-size: 14px;
  letter-spacing: 0.06em;
}

.scroll-cue i {
  width: 1px;
  height: 42px;
  background: linear-gradient(rgba(255, 255, 255, 0.82), transparent);
}

.scroll-cue:hover {
  color: var(--white);
}

.content-shell {
  min-height: 82vh;
  padding: calc(var(--header-height) + clamp(76px, 8vw, 118px)) clamp(20px, 6vw, 88px) clamp(76px, 8vw, 118px);
  background: var(--paper);
  scroll-margin-top: var(--header-height);
}

.page-panel {
  display: none;
  width: min(1280px, 100%);
  margin: 0 auto;
  animation: panelIn 520ms cubic-bezier(0.22, 1, 0.36, 1);
}

.page-panel.is-active {
  display: block;
}

.page-panel[data-page="people"].is-active {
  width: min(1320px, 100%);
}

#culture.is-active {
  display: grid;
  grid-template-columns: 280px minmax(0, 1280px);
  gap: 120px;
  align-items: start;
  width: calc(100vw - 24px);
  max-width: none;
  margin-left: calc(50% - 50vw + 12px);
  animation: none;
  opacity: 1;
  transform: none;
}

#culture > .culture-month-switcher {
  position: fixed;
  top: var(--header-height);
  left: 12px;
  width: 280px;
  margin: 0;
  grid-column: 1;
  grid-row: 1 / span 100;
}

#culture > .culture-empty,
#culture > .culture-showcase {
  grid-column: 2;
  width: min(1280px, 100%);
  transform: translateX(clamp(16px, 1.5vw, 24px));
}

@keyframes panelIn {
  from {
    opacity: 0;
    transform: translateY(20px);
  }
  to {
    opacity: 1;
    transform: translateY(0);
  }
}

.home-hero {
  display: grid;
  grid-template-columns: minmax(280px, 0.92fr) minmax(320px, 1.08fr);
  gap: clamp(28px, 5vw, 76px);
  align-items: end;
  margin-bottom: 34px;
}

.home-hero h2,
.page-title h2 {
  margin: 0;
  font-size: clamp(34px, 4.8vw, 64px);
  line-height: 1.14;
  letter-spacing: 0;
}

.home-hero p:last-child,
.page-title + p {
  color: var(--muted);
  font-size: 18px;
}

.home-grid,
.research-cards,
.culture-grid {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: 18px;
}

.feature-card,
.research-cards article,
.student-card,
.culture-grid article,
.news-list article,
.progress-item,
.team-entry,
.contact-entry,
.join-panel {
  border: 1px solid var(--line);
  border-radius: 6px;
  background: var(--white);
  box-shadow: 0 16px 42px rgba(18, 24, 28, 0.08);
}

.feature-card {
  min-height: 220px;
  padding: clamp(24px, 3vw, 34px);
}

.feature-card.wide {
  grid-column: span 1;
  color: var(--white);
  background: linear-gradient(135deg, var(--pku-red-deep), #263135);
}

.feature-card span {
  color: var(--gold);
  font-size: 13px;
  font-weight: 900;
}

.feature-card h3 {
  margin: 16px 0 12px;
  font-size: clamp(22px, 2.4vw, 32px);
  line-height: 1.25;
}

.feature-card p {
  margin: 0;
  color: var(--muted);
}

.feature-card.wide p {
  color: rgba(255, 255, 255, 0.76);
}

.home-lab-layout {
  display: grid;
  grid-template-columns: minmax(0, 1.2fr) minmax(300px, 0.8fr);
  gap: 20px;
  margin-top: 20px;
}

.news-window {
  padding: clamp(24px, 3vw, 34px);
  border: 1px solid var(--line);
  border-radius: 6px;
  background: var(--white);
}

.block-title {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 16px;
  margin-bottom: 20px;
}

.block-title button,
.team-entry button,
.contact-entry button {
  border: 0;
  color: var(--pku-red);
  background: transparent;
  font-weight: 900;
}

.progress-item {
  padding: 22px;
  box-shadow: none;
}

.progress-item + .progress-item {
  margin-top: 12px;
}

.progress-item time,
.news-list time,
.news-line time,
.timeline-list time {
  color: var(--pku-red);
  font-weight: 900;
}

.progress-item h3,
.news-line h3 {
  margin: 10px 0 8px;
  font-size: 22px;
}

.progress-item p {
  margin: 0;
  color: var(--muted);
}

.side-stack {
  display: grid;
  gap: 20px;
}

.team-entry,
.contact-entry {
  min-height: 220px;
  padding: 28px;
}

.team-entry {
  color: var(--white);
  background: linear-gradient(135deg, #263135, var(--pku-red-deep));
}

.team-entry p,
.contact-entry p {
  margin: 0 0 12px;
  color: var(--gold);
  font-weight: 900;
}

.team-entry h3,
.contact-entry h3 {
  margin: 0 0 24px;
  font-size: 26px;
}

.team-entry button {
  color: var(--white);
}

.home-news {
  margin-top: 20px;
  padding: clamp(24px, 3vw, 34px);
  border: 1px solid var(--line);
  border-radius: 6px;
  background: var(--white);
}

.news-line {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 18px;
}

.news-line article {
  padding-top: 18px;
  border-top: 1px solid var(--line);
}

.page-title {
  max-width: 900px;
  margin-bottom: 34px;
}

.research-cards article {
  padding: clamp(26px, 4vw, 44px);
}

.research-cards article span {
  color: var(--gold);
  font-family: Georgia, "Times New Roman", serif;
  font-size: 58px;
  line-height: 1;
}

.research-cards article h3 {
  margin: 24px 0 16px;
  font-size: clamp(24px, 3vw, 36px);
  line-height: 1.26;
}

.research-cards article p,
.student-card p,
.culture-grid p,
.timeline-list p,
.join-panel p {
  color: var(--muted);
}

.timeline-list,
.news-list {
  display: grid;
  gap: 16px;
}

.timeline-list article,
.news-list article {
  padding: clamp(24px, 3vw, 34px);
  border-left: 5px solid var(--pku-red);
  background: var(--white);
  box-shadow: 0 12px 34px rgba(18, 24, 28, 0.07);
}

.timeline-list h3,
.news-list h3 {
  margin: 10px 0;
  font-size: 24px;
}

.academic-news-layout {
  display: grid;
  grid-template-columns: minmax(0, 1fr) 250px;
  gap: clamp(30px, 4vw, 58px);
  align-items: start;
}

.academic-news-main {
  display: grid;
  gap: 18px;
}

.academic-news-card {
  padding: clamp(24px, 3vw, 34px);
  border: 1px solid rgba(23, 27, 29, 0.1);
  border-radius: 6px;
  background: rgba(255, 255, 255, 0.96);
  box-shadow: 0 8px 24px rgba(18, 24, 28, 0.06);
  transition: border-color 180ms ease, box-shadow 180ms ease, transform 180ms ease;
}

.academic-news-card:hover {
  border-color: rgba(140, 0, 11, 0.22);
  box-shadow: 0 14px 34px rgba(18, 24, 28, 0.1);
  transform: translateY(-2px);
}

.academic-news-card[hidden] {
  display: none;
}

.academic-news-card h2 {
  margin: 0 0 14px;
  color: var(--ink);
  font-size: clamp(22px, 2vw, 29px);
  line-height: 1.42;
}

.academic-news-card p {
  margin: 0;
  color: var(--muted);
  font-size: 16px;
  line-height: 1.9;
}

.academic-news-card footer {
  display: flex;
  flex-wrap: wrap;
  gap: 8px 24px;
  margin-top: 18px;
  padding-top: 14px;
  border-top: 1px solid rgba(23, 27, 29, 0.08);
  color: rgba(104, 112, 116, 0.8);
  font-size: 14px;
}

.news-archive {
  position: sticky;
  top: calc(var(--header-height) + 28px);
  overflow: hidden;
  border: 1px solid rgba(23, 27, 29, 0.1);
  border-radius: 6px;
  background: rgba(255, 255, 255, 0.94);
  box-shadow: 0 10px 28px rgba(18, 24, 28, 0.07);
}

.news-archive h2 {
  margin: 0;
  padding: 18px 20px;
  color: var(--ink);
  background: rgba(23, 27, 29, 0.1);
  font-size: 18px;
}

.news-year-list {
  display: grid;
  padding: 8px 18px 18px;
}

.news-year-list button {
  min-height: 48px;
  padding: 0 4px;
  border: 0;
  border-bottom: 1px solid rgba(23, 27, 29, 0.12);
  color: #4e565a;
  background: transparent;
  text-align: left;
  transition: color 180ms ease, padding 180ms ease, background 180ms ease;
}

.news-year-list button:hover,
.news-year-list button.is-active {
  padding-left: 12px;
  color: var(--pku-red);
  background: linear-gradient(90deg, rgba(140, 0, 11, 0.06), transparent 82%);
}

.academic-news-empty {
  min-height: 260px;
  margin: 0;
  display: grid;
  place-items: center;
  color: var(--muted);
  font-size: 20px;
  font-weight: 800;
  text-align: center;
}

.academic-news-empty[hidden] {
  display: none;
}

.culture-month-switcher {
  position: sticky;
  top: var(--header-height);
  z-index: 60;
  display: grid;
  width: 100%;
  gap: 14px;
  margin: 22px 0 28px;
  padding: 24px 20px;
  border: 1px solid rgba(23, 27, 29, 0.08);
  border-radius: 8px;
  background: rgba(255, 255, 255, 0.9);
  box-shadow: 0 10px 28px rgba(18, 24, 28, 0.08);
  backdrop-filter: blur(14px) saturate(1.18);
}

.culture-year-nav {
  display: inline-grid;
  grid-template-columns: 46px auto 46px;
  gap: 14px;
  align-items: center;
  justify-self: center;
}

.culture-year-nav strong {
  min-width: 90px;
  color: var(--ink);
  font-family: Georgia, "Times New Roman", serif;
  font-size: 25px;
  line-height: 1;
  text-align: center;
}

.culture-month-grid {
  display: grid;
  grid-template-columns: repeat(4, minmax(0, 1fr));
  gap: 12px 10px;
}

.culture-month-switcher button {
  min-width: 0;
  height: 46px;
  border: 1px solid rgba(23, 27, 29, 0.1);
  border-radius: 999px;
  color: var(--ink);
  background: rgba(255, 255, 255, 0.72);
  font-family: Georgia, "Times New Roman", serif;
  font-size: 17px;
  font-weight: 900;
  white-space: nowrap;
  box-shadow: inset 0 1px 0 rgba(255, 255, 255, 0.72);
  transition: color 180ms ease, border-color 180ms ease, background 180ms ease, transform 180ms ease, box-shadow 180ms ease;
}

.culture-month-switcher button:hover,
.culture-month-switcher button.is-active {
  color: var(--pku-red);
  border-color: rgba(140, 0, 11, 0.26);
  background: rgba(140, 0, 11, 0.08);
  box-shadow: 0 8px 18px rgba(140, 0, 11, 0.08);
  transform: translateY(-1px);
}

.culture-month-switcher button:disabled {
  cursor: not-allowed;
  color: rgba(99, 108, 113, 0.36);
  background: rgba(23, 27, 29, 0.04);
  transform: none;
}

.culture-empty {
  display: flex;
  min-height: clamp(280px, 48vh, 520px);
  align-items: center;
  justify-content: center;
  padding: 0;
  border: 0;
  background: transparent;
  box-shadow: none;
  text-align: center;
}

.culture-empty[hidden],
.culture-showcase[hidden] {
  display: none !important;
}

.culture-empty strong {
  color: var(--muted);
  font-size: clamp(22px, 2.2vw, 30px);
  font-weight: 900;
}

.culture-showcase {
  position: relative;
  display: grid;
  grid-template-columns: minmax(280px, 0.95fr) minmax(360px, 1.15fr);
  align-items: center;
  min-height: clamp(480px, 54vw, 640px);
  padding: clamp(4px, 1.8vw, 28px) 0 clamp(32px, 5vw, 72px);
}

.culture-carousel {
  position: relative;
  z-index: 2;
  width: calc(100% + clamp(48px, 7vw, 120px));
  margin-left: clamp(-120px, -7vw, -48px);
  min-height: clamp(280px, 31vw, 430px);
  overflow: hidden;
  border: 1px solid rgba(23, 27, 29, 0.08);
  background: #f3f1ee;
  box-shadow: 0 20px 48px rgba(18, 24, 28, 0.1);
}

.culture-carousel img {
  position: absolute;
  inset: 0;
  width: 100%;
  height: 100%;
  object-fit: cover;
  opacity: 0;
  transform: scale(1.02);
  transition: opacity 520ms ease, transform 1600ms ease;
}

.culture-carousel img.is-active {
  opacity: 1;
  transform: scale(1);
}

.culture-story {
  display: grid;
  grid-template-rows: minmax(160px, 0.7fr) minmax(280px, 1fr);
  min-height: clamp(430px, 44vw, 560px);
  margin-left: clamp(-90px, -5vw, -42px);
  background: #eeeae8;
}

.culture-story-head {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding:
    clamp(38px, 6vw, 74px)
    clamp(36px, 7vw, 92px)
    clamp(38px, 6vw, 74px)
    clamp(74px, 9vw, 128px);
}

.culture-story-head h2 {
  margin: 0;
  color: var(--ink);
  font-size: clamp(34px, 4.2vw, 52px);
  font-weight: 500;
  line-height: 1.1;
}

.culture-story-body {
  display: grid;
  align-content: center;
  gap: clamp(54px, 7vw, 90px);
  padding:
    clamp(40px, 6vw, 76px)
    clamp(56px, 7.5vw, 108px)
    clamp(40px, 6vw, 76px)
    clamp(74px, 9vw, 128px);
  color: var(--white);
  background: #9a7b76;
}

.culture-story-body h3 {
  max-width: 620px;
  margin: 0;
  font-size: clamp(23px, 2.25vw, 34px);
  line-height: 1.65;
  font-weight: 500;
}

.culture-story-body time {
  color: rgba(255, 255, 255, 0.92);
  font-family: Georgia, "Times New Roman", serif;
  font-size: 18px;
  font-style: italic;
  font-weight: 800;
}

.project-tags {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
  margin-top: 16px;
}

.project-tags span {
  padding: 5px 10px;
  border: 1px solid rgba(140, 0, 11, 0.12);
  border-radius: 999px;
  color: var(--pku-red);
  background: rgba(140, 0, 11, 0.05);
  font-size: 12px;
  font-weight: 900;
}

.achievement-layout {
  display: grid;
  grid-template-columns: 240px minmax(0, 1fr);
  gap: clamp(20px, 3vw, 36px);
  align-items: start;
  padding: clamp(18px, 2.4vw, 28px);
  border: 1px solid var(--line);
  border-radius: 8px;
  background:
    linear-gradient(90deg, rgba(255, 255, 255, 0.96), rgba(255, 255, 255, 0.93)),
    url("./assets/lab-hero.webp") center / cover;
  box-shadow: 0 18px 52px rgba(18, 24, 28, 0.08);
}

.achievement-main {
  min-width: 0;
  padding: clamp(18px, 2.5vw, 28px);
  border: 1px solid rgba(23, 27, 29, 0.08);
  border-radius: 8px;
  background: rgba(255, 255, 255, 0.94);
  box-shadow: 0 16px 42px rgba(18, 24, 28, 0.06);
}

.achievement-panel {
  display: none;
}

.achievement-panel.is-active {
  display: grid;
  gap: 18px;
}

.achievement-heading {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 18px;
  padding-bottom: 14px;
  border-bottom: 1px solid rgba(23, 27, 29, 0.12);
}

.achievement-heading p {
  margin: 0 0 8px;
  color: var(--pku-red);
  font-weight: 900;
}

.achievement-heading h3 {
  margin: 0;
  font-size: clamp(30px, 3.4vw, 42px);
  line-height: 1.2;
}

.achievement-heading span {
  flex: 0 0 auto;
  padding: 6px 12px;
  border-radius: 999px;
  color: var(--pku-red-deep);
  background: rgba(140, 0, 11, 0.08);
  font-size: 13px;
  font-weight: 900;
}

.paper-year-filter {
  display: grid;
  grid-template-columns: repeat(10, minmax(0, 1fr));
  gap: 0;
  padding: 10px 14px;
  border-top: 1px solid rgba(23, 27, 29, 0.1);
  border-bottom: 1px solid rgba(23, 27, 29, 0.1);
  background: rgba(255, 255, 255, 0.72);
}

.paper-year-filter button {
  position: relative;
  min-width: 0;
  width: 100%;
  min-height: 36px;
  border: 0;
  border-radius: 0;
  color: var(--ink);
  background: transparent;
  font-family: Georgia, "Times New Roman", serif;
  font-size: 17px;
  font-weight: 800;
  transition: color 180ms ease, transform 180ms ease, background 180ms ease;
}

.paper-year-filter button + button::before {
  content: "";
  position: absolute;
  top: 11px;
  left: 0;
  width: 1px;
  height: 14px;
  background: rgba(23, 27, 29, 0.18);
}

.paper-year-filter button:nth-child(10n + 1)::before {
  display: none;
}

.paper-year-filter button::after {
  content: "";
  position: absolute;
  left: 22px;
  right: 22px;
  bottom: 4px;
  height: 2px;
  background: currentColor;
  transform: scaleX(0);
  transform-origin: center;
  transition: transform 180ms ease;
}

.paper-year-filter button:hover {
  color: var(--pku-red);
  background: rgba(140, 0, 11, 0.04);
  transform: translateY(-1px);
}

.paper-year-filter button:hover::after,
.paper-year-filter button.is-active::after {
  transform: scaleX(1);
}

.paper-year-filter button.is-active {
  color: var(--pku-red);
  background: rgba(140, 0, 11, 0.06);
}

.paper-search {
  position: relative;
  display: grid;
  gap: 10px;
  padding: 14px;
  border: 1px solid rgba(23, 27, 29, 0.1);
  border-radius: 8px;
  background:
    linear-gradient(135deg, rgba(255, 255, 255, 0.96), rgba(255, 255, 255, 0.9)),
    rgba(255, 255, 255, 0.88);
  box-shadow: 0 10px 24px rgba(18, 24, 28, 0.05);
  backdrop-filter: blur(8px);
}

.paper-search::before {
  content: "";
  position: absolute;
  top: -1px;
  left: 14px;
  width: 128px;
  height: 3px;
  border-radius: 0 0 999px 999px;
  background: var(--pku-red);
}

.paper-search-grid {
  display: grid;
  grid-template-columns: minmax(170px, 1.05fr) minmax(130px, 0.9fr) minmax(120px, 0.8fr) minmax(135px, 0.9fr) 92px 104px;
  gap: 8px;
  align-items: end;
}

.paper-search label {
  display: grid;
  gap: 6px;
  align-content: start;
  min-width: 0;
  color: var(--muted);
  font-size: 12px;
  font-weight: 800;
}

.paper-search label > span {
  letter-spacing: 0;
}

.paper-search input[type="number"],
.paper-search input[type="search"] {
  width: 100%;
  height: 36px;
  border: 1px solid rgba(23, 27, 29, 0.12);
  border-radius: 4px;
  background: rgba(255, 255, 255, 0.92);
  padding: 0 10px;
  color: var(--ink);
  outline: none;
  font-size: 14px;
  font-weight: 700;
  transition: border-color 180ms ease, box-shadow 180ms ease, background 180ms ease;
}

.paper-range-inputs {
  display: grid;
  grid-template-columns: minmax(0, 1fr) auto minmax(0, 1fr);
  gap: 6px;
  align-items: center;
}

.paper-range-inputs em {
  color: var(--muted);
  font-style: normal;
  font-weight: 900;
}

.paper-search input::placeholder {
  color: rgba(99, 108, 113, 0.58);
  font-weight: 600;
}

.paper-search input:focus {
  border-color: rgba(140, 0, 11, 0.42);
  background: var(--white);
  box-shadow: 0 0 0 3px rgba(140, 0, 11, 0.08);
}

.paper-search button {
  align-self: end;
  min-width: 0;
  height: 36px;
  border: 1px solid rgba(140, 0, 11, 0.18);
  border-radius: 4px;
  color: var(--white);
  background: linear-gradient(135deg, var(--pku-red), #4a151c);
  font-size: 14px;
  font-weight: 900;
  box-shadow: 0 8px 18px rgba(140, 0, 11, 0.14);
  transition: transform 180ms ease, box-shadow 180ms ease, filter 180ms ease;
}

.paper-search button:hover {
  filter: brightness(1.05);
  transform: translateY(-1px);
  box-shadow: 0 16px 30px rgba(140, 0, 11, 0.2);
}

.paper-reset {
  color: var(--ink) !important;
  background: rgba(23, 27, 29, 0.08) !important;
  border-color: rgba(23, 27, 29, 0.1) !important;
  box-shadow: none !important;
}

.paper-result {
  margin: 0;
  width: fit-content;
  padding: 5px 10px;
  border-radius: 999px;
  color: var(--pku-red-deep);
  background: rgba(140, 0, 11, 0.07);
  font-size: 13px;
  font-weight: 800;
}

.paper-search-meta {
  display: flex;
  align-items: center;
  gap: 10px;
  min-width: 0;
}

.list-pagination {
  display: flex;
  align-items: center;
  justify-content: center;
  flex-wrap: wrap;
  gap: 8px;
  margin-top: 10px;
  padding-top: 10px;
  border-top: 1px solid rgba(23, 27, 29, 0.08);
}

.list-pagination[hidden] {
  display: none !important;
}

.list-pagination button {
  min-width: 36px;
  height: 34px;
  border: 1px solid rgba(23, 27, 29, 0.12);
  border-radius: 4px;
  color: var(--ink);
  background: rgba(255, 255, 255, 0.86);
  font-weight: 900;
  transition: color 180ms ease, border-color 180ms ease, background 180ms ease, transform 180ms ease;
}

.list-pagination button:hover:not(:disabled),
.list-pagination button.is-active {
  color: var(--pku-red);
  border-color: rgba(140, 0, 11, 0.26);
  background: rgba(140, 0, 11, 0.06);
  transform: translateY(-1px);
}

.list-pagination button:disabled {
  cursor: not-allowed;
  color: rgba(99, 108, 113, 0.46);
  background: rgba(23, 27, 29, 0.04);
}

.paper-year {
  display: none;
  gap: 14px;
}

.paper-year.is-active {
  display: grid;
}

.empty-output,
.paper-card,
.patent-card {
  border: 1px solid rgba(23, 27, 29, 0.1);
  border-radius: 8px;
  background: rgba(255, 255, 255, 0.9);
  box-shadow: 0 14px 36px rgba(18, 24, 28, 0.07);
}

.empty-output {
  padding: clamp(22px, 3vw, 30px);
}

.empty-output strong {
  display: block;
  color: var(--ink);
  font-size: 22px;
}

.empty-output p {
  margin: 10px 0 0;
  color: var(--muted);
}

.paper-card {
  display: grid;
  grid-template-columns: 54px minmax(0, 1fr);
  gap: 18px;
  align-items: start;
  padding: clamp(20px, 2.5vw, 26px);
  background: var(--white);
}

.paper-card[hidden] {
  display: none !important;
}

.paper-card[data-pagination-hidden="true"],
.paper-year[data-pagination-hidden="true"],
.patent-card[data-pagination-hidden="true"],
.patent-year-group[data-pagination-hidden="true"],
.project-list > article[data-pagination-hidden="true"],
.graduate-year[data-pagination-hidden="true"],
.member-card[data-pagination-hidden="true"],
.alumni-card[data-pagination-hidden="true"],
.alumni-year[data-pagination-hidden="true"] {
  display: none !important;
}

.paper-card.has-image {
  grid-template-columns: 54px minmax(0, 1fr);
}

.paper-figure {
  width: min(560px, 100%);
  margin: 18px 0 0;
  overflow: hidden;
  border: 1px solid rgba(23, 27, 29, 0.06);
  border-radius: 4px;
  background: rgba(255, 255, 255, 0.72);
}

.paper-figure button {
  display: block;
  width: 100%;
  border: 0;
  background: transparent;
  padding: 0;
  cursor: zoom-in;
}

.paper-figure img {
  display: block;
  width: 100%;
  height: 240px;
  object-fit: contain;
  transition: transform 180ms ease, filter 180ms ease;
}

.paper-figure button:hover img {
  filter: saturate(1.04) contrast(1.02);
  transform: scale(1.01);
}

.paper-index {
  color: rgba(140, 0, 11, 0.78);
  font-family: Georgia, "Times New Roman", serif;
  font-size: 34px;
  line-height: 1;
}

.paper-card h5,
.patent-card h4 {
  margin: 0 0 10px;
  color: var(--ink);
  font-size: clamp(20px, 2vw, 26px);
  line-height: 1.28;
}

.paper-card h5 {
  font-weight: 950;
}

.paper-card p {
  margin: 0 0 14px;
  color: var(--muted);
}

.paper-card dl,
.patent-card dl {
  display: grid;
  grid-template-columns: 74px 150px minmax(0, 1fr);
  gap: 10px 16px;
  margin: 0;
}

.paper-card dl div {
  min-width: 0;
}

.paper-card .paper-meta-journal {
  grid-column: 1 / -1;
}

.patent-card dl {
  grid-template-columns: repeat(2, minmax(0, 1fr));
}

.paper-card dt,
.patent-card dt {
  color: var(--muted);
  font-size: 13px;
  font-weight: 800;
}

.paper-card dd,
.patent-card dd {
  margin: 0;
  color: var(--ink);
  font-weight: 800;
  overflow-wrap: normal;
}

.paper-card dd {
  white-space: nowrap;
  overflow: visible;
  text-overflow: clip;
}

.paper-card .paper-meta-doi {
  min-width: 0;
}

.paper-card .paper-meta-doi dd {
  min-width: 0;
  overflow: hidden;
  text-overflow: ellipsis;
}

.paper-card dd a {
  display: inline-block;
  max-width: 100%;
  overflow: hidden;
  overflow-y: hidden;
  color: var(--pku-red);
  text-decoration: underline;
  text-underline-offset: 3px;
  white-space: nowrap;
  text-overflow: ellipsis;
}

.paper-card .paper-meta-journal dd {
  display: flex;
  align-items: center;
  gap: 10px;
  white-space: normal;
}

.paper-journal-name {
  display: inline-block;
  flex: 1 1 auto;
  min-width: 0;
  padding: 2px 5px 2px 0;
  color: var(--pku-red);
  font-style: italic;
  line-height: 1.45;
  white-space: nowrap;
  overflow: hidden;
  text-overflow: ellipsis;
}

.paper-tags {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
  margin-top: 14px;
}

.paper-tags span {
  padding: 5px 9px;
  border: 1px solid rgba(140, 0, 11, 0.12);
  border-radius: 999px;
  color: var(--pku-red);
  background: rgba(140, 0, 11, 0.05);
  font-size: 12px;
  font-weight: 900;
}

.paper-tags-inline {
  flex: 0 0 auto;
  margin-top: 0;
  margin-left: auto;
}

.image-lightbox {
  position: fixed;
  inset: 0;
  z-index: 300;
  display: grid;
  place-items: center;
  padding: clamp(20px, 4vw, 56px);
  background: rgba(8, 10, 12, 0.78);
  opacity: 0;
  pointer-events: none;
  transition: opacity 180ms ease;
}

.image-lightbox.is-open {
  opacity: 1;
  pointer-events: auto;
}

.image-lightbox img {
  display: block;
  max-width: min(1100px, 94vw);
  max-height: 86vh;
  object-fit: contain;
  border-radius: 6px;
  background: var(--white);
  box-shadow: 0 30px 80px rgba(0, 0, 0, 0.38);
}

.image-lightbox-close {
  position: fixed;
  top: 22px;
  right: 24px;
  display: grid;
  width: 42px;
  height: 42px;
  place-items: center;
  border: 1px solid rgba(255, 255, 255, 0.4);
  border-radius: 50%;
  color: var(--white);
  background: rgba(255, 255, 255, 0.12);
  font-size: 30px;
  line-height: 1;
}

body.lightbox-open {
  overflow: hidden;
}

.patent-list {
  display: grid;
  gap: 24px;
}

.patent-year-group {
  display: grid;
  gap: 14px;
}

.patent-year-group + .patent-year-group {
  padding-top: 22px;
  border-top: 1px solid rgba(23, 27, 29, 0.1);
}

.patent-year-title {
  display: flex;
  align-items: center;
  gap: 10px;
  margin: 0;
  color: var(--ink);
  font-size: clamp(19px, 1.9vw, 24px);
  font-weight: 950;
}

.patent-year-title::before {
  content: "";
  width: 4px;
  height: 22px;
  border-radius: 999px;
  background: var(--pku-red);
}

.patent-card {
  display: grid;
  grid-template-columns: 92px minmax(0, 1fr);
  gap: 18px;
  padding: clamp(22px, 3vw, 30px);
}

.patent-status {
  display: grid;
  width: 76px;
  height: 76px;
  place-items: center;
  border-radius: 50%;
  color: var(--white);
  background: linear-gradient(135deg, var(--pku-red), #263135);
  font-weight: 900;
}

.achievement-switcher {
  position: sticky;
  top: calc(var(--header-height) + 28px);
  display: grid;
  gap: 8px;
  padding: 12px;
  border: 1px solid rgba(23, 27, 29, 0.08);
  border-left: 4px solid var(--pku-red);
  border-radius: 6px;
  background: rgba(255, 255, 255, 0.96);
  box-shadow: 0 12px 30px rgba(18, 24, 28, 0.07);
}

.achievement-switcher button {
  position: relative;
  min-height: 50px;
  padding: 0 14px 0 18px;
  border: 0;
  color: var(--ink);
  border-radius: 4px;
  background: transparent;
  font-weight: 900;
  text-align: left;
  transition: color 180ms ease, background 180ms ease;
}

.achievement-switcher button::before {
  content: "";
  position: absolute;
  top: 12px;
  bottom: 12px;
  left: 0;
  width: 3px;
  border-radius: 999px;
  background: transparent;
}

.achievement-switcher button:hover,
.achievement-switcher button.is-active {
  color: var(--pku-red);
  background: rgba(140, 0, 11, 0.06);
}

.achievement-switcher button.is-active::before {
  background: var(--pku-red);
}

.people-layout {
  display: grid;
  grid-template-columns: minmax(280px, 0.9fr) minmax(320px, 1.1fr);
  gap: 20px;
}

.member-layout {
  display: grid;
  grid-template-columns: 220px minmax(0, 1fr);
  gap: clamp(28px, 4vw, 56px);
  align-items: start;
  padding: clamp(24px, 3vw, 34px);
  border: 1px solid var(--line);
  border-radius: 8px;
  background:
    linear-gradient(90deg, rgba(255, 255, 255, 0.96), rgba(255, 255, 255, 0.93)),
    url("./assets/lab-hero.webp") center / cover;
  box-shadow: 0 18px 52px rgba(18, 24, 28, 0.08);
}

.member-sidebar {
  position: sticky;
  top: calc(var(--header-height) + 28px);
  display: grid;
  gap: 8px;
  padding: 12px;
  border-left: 4px solid var(--pku-red);
  background: var(--white);
  box-shadow: 0 12px 34px rgba(18, 24, 28, 0.06);
}

.member-sidebar button {
  min-height: 52px;
  padding: 0 18px;
  border: 0;
  color: rgba(23, 27, 29, 0.78);
  background: transparent;
  text-align: left;
  font-size: 17px;
  font-weight: 800;
  transition: color 180ms ease, background 180ms ease, transform 180ms ease;
}

.member-sidebar button:hover,
.member-sidebar button.is-active {
  color: var(--pku-red);
  background: rgba(140, 0, 11, 0.06);
  transform: translateX(4px);
}

.member-panel {
  display: none;
  animation: panelIn 420ms cubic-bezier(0.22, 1, 0.36, 1);
}

.member-panel.is-active {
  display: block;
}

.advisor-profile {
  display: grid;
  grid-template-columns: 220px minmax(0, 1fr);
  gap: clamp(24px, 4vw, 44px);
  align-items: start;
  padding: clamp(24px, 3.2vw, 38px);
  border: 1px solid rgba(23, 27, 29, 0.1);
  border-radius: 8px;
  background:
    linear-gradient(135deg, rgba(255, 255, 255, 0.98), rgba(255, 255, 255, 0.92)),
    var(--white);
  box-shadow: 0 18px 42px rgba(18, 24, 28, 0.07);
}

.advisor-photo {
  display: grid;
  width: 220px;
  aspect-ratio: 3 / 4;
  place-items: center;
  border: 1px solid rgba(140, 0, 11, 0.18);
  border-radius: 6px;
  color: var(--pku-red-deep);
  background:
    linear-gradient(135deg, rgba(140, 0, 11, 0.1), rgba(47, 140, 140, 0.12)),
    var(--white);
  font-size: 72px;
  font-weight: 900;
}

.advisor-info {
  min-width: 0;
}

.member-role {
  margin: 0 0 8px;
  color: var(--pku-red);
  font-weight: 900;
}

.advisor-info h3 {
  margin: 0 0 18px;
  font-size: clamp(34px, 4vw, 52px);
  line-height: 1.12;
}

.advisor-info dl {
  display: grid;
  gap: 0;
  margin: 0 0 22px;
  border-top: 1px solid var(--line);
}

.advisor-info dl div {
  display: grid;
  grid-template-columns: 110px minmax(0, 1fr);
  gap: 18px;
  padding: 13px 0;
  border-bottom: 1px solid var(--line);
}

.advisor-info dt {
  color: var(--muted);
  font-weight: 800;
}

.advisor-info dd {
  margin: 0;
}

.advisor-info p {
  color: var(--muted);
}

.advisor-message strong {
  color: #000;
  font-weight: 900;
}

.advisor-info a {
  display: inline-flex;
  margin-top: 8px;
  color: var(--pku-red);
  font-weight: 900;
}

.advisor-info .profile-link {
  color: #7a2cff;
  text-underline-offset: 5px;
  transition: color 180ms ease;
}

.advisor-info .profile-link::after {
  content: "";
  display: inline-block;
  width: 1.05em;
  height: 1.05em;
  margin-left: 3px;
  background: currentColor;
  transform: translateY(2px) rotate(-45deg);
  mask: url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' viewBox='0 0 24 24' fill='none' stroke='black' stroke-width='2.8' stroke-linecap='round' stroke-linejoin='round'%3E%3Cpath d='M9 17H7A5 5 0 0 1 7 7h2'/%3E%3Cpath d='M15 7h2a5 5 0 1 1 0 10h-2'/%3E%3Cpath d='M8 12h8'/%3E%3C/svg%3E") center / contain no-repeat;
  -webkit-mask: url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' viewBox='0 0 24 24' fill='none' stroke='black' stroke-width='2.8' stroke-linecap='round' stroke-linejoin='round'%3E%3Cpath d='M9 17H7A5 5 0 0 1 7 7h2'/%3E%3Cpath d='M15 7h2a5 5 0 1 1 0 10h-2'/%3E%3Cpath d='M8 12h8'/%3E%3C/svg%3E") center / contain no-repeat;
}

.advisor-info .profile-link:hover {
  color: #5b18d6;
}

.member-card-grid {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 18px;
}

.member-card {
  min-height: 250px;
  padding: clamp(24px, 3vw, 34px);
  border: 1px solid var(--line);
  border-radius: 6px;
  background: var(--white);
  box-shadow: 0 12px 34px rgba(18, 24, 28, 0.06);
}

.member-avatar {
  display: grid;
  width: 68px;
  height: 68px;
  margin-bottom: 22px;
  place-items: center;
  border-radius: 50%;
  color: var(--white);
  background: linear-gradient(135deg, var(--pku-red), #263135);
  font-size: 24px;
  font-weight: 900;
}

.member-card h3 {
  margin: 0 0 12px;
  font-size: 26px;
}

.member-card p {
  margin: 0;
  color: var(--muted);
}

.member-panel[data-team-panel="alumni"] > .member-card-grid {
  display: none;
}

.alumni-directory {
  display: grid;
  gap: 34px;
}

.alumni-year {
  display: grid;
  gap: 14px;
}

.alumni-year header {
  display: flex;
  align-items: center;
  gap: 16px;
  color: var(--ink);
  font-weight: 900;
}

.alumni-year header::after {
  content: "";
  height: 1px;
  flex: 1;
  background: linear-gradient(90deg, rgba(23, 27, 29, 0.18), transparent);
}

.alumni-year header span {
  padding: 6px 12px;
  border: 1px solid rgba(23, 27, 29, 0.1);
  border-radius: 999px;
  background: rgba(255, 255, 255, 0.78);
  box-shadow: 0 8px 22px rgba(18, 24, 28, 0.05);
}

.alumni-card {
  display: grid;
  grid-template-columns: 132px minmax(0, 1fr);
  gap: clamp(18px, 3vw, 30px);
  align-items: start;
  padding: clamp(20px, 3vw, 30px);
  border: 1px solid rgba(23, 27, 29, 0.08);
  border-radius: 18px;
  background:
    linear-gradient(135deg, rgba(255, 255, 255, 0.96), rgba(248, 249, 250, 0.9)),
    var(--white);
  box-shadow: 0 20px 54px rgba(18, 24, 28, 0.08);
  transition: transform 220ms ease, box-shadow 220ms ease, border-color 220ms ease;
}

.alumni-card:hover {
  border-color: rgba(23, 27, 29, 0.16);
  box-shadow: 0 28px 72px rgba(18, 24, 28, 0.12);
  transform: translateY(-2px);
}

.alumni-portrait {
  display: grid;
  width: 132px;
  aspect-ratio: 1;
  place-items: center;
  border-radius: 34px;
  color: var(--white);
  background:
    radial-gradient(circle at 30% 20%, rgba(255, 255, 255, 0.75), transparent 22%),
    linear-gradient(145deg, #8c000b, #273136 52%, #2f8c8c);
  box-shadow: inset 0 0 0 1px rgba(255, 255, 255, 0.26), 0 18px 34px rgba(18, 24, 28, 0.18);
  font-size: 42px;
  font-weight: 900;
}

.alumni-portrait img {
  width: 100%;
  height: 100%;
  object-fit: contain;
}

.alumni-portrait-photo {
  overflow: hidden;
  background: #f5f5f7;
}

.alumni-main {
  min-width: 0;
}

.alumni-head {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 16px;
  padding-bottom: 14px;
  border-bottom: 1px solid rgba(23, 27, 29, 0.08);
}

.alumni-head h3 {
  margin: 0;
  font-size: clamp(24px, 3vw, 34px);
  line-height: 1.2;
  letter-spacing: 0;
}

.alumni-head span {
  flex: 0 0 auto;
  padding: 5px 12px;
  border-radius: 999px;
  color: var(--pku-red-deep);
  background: rgba(140, 0, 11, 0.08);
  font-size: 13px;
  font-weight: 900;
}

.alumni-timeline {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
  margin: 16px 0 18px;
}

.alumni-timeline p {
  margin: 0;
  padding: 7px 10px;
  border-radius: 999px;
  color: #3d4549;
  background: rgba(23, 27, 29, 0.04);
  font-size: 14px;
  line-height: 1.45;
}

.alumni-card dl {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 10px 18px;
  margin: 0;
}

.alumni-card dl div {
  min-width: 0;
  padding-top: 10px;
  border-top: 1px solid rgba(23, 27, 29, 0.07);
}

.alumni-card dt {
  margin-bottom: 3px;
  color: var(--muted);
  font-size: 13px;
  font-weight: 800;
}

.alumni-card dd {
  margin: 0;
  color: var(--ink);
  font-weight: 700;
  overflow-wrap: anywhere;
}

.pi-card {
  padding: clamp(28px, 5vw, 48px);
  color: var(--white);
  border-radius: 6px;
  background: linear-gradient(135deg, var(--pku-red-deep), #263135);
}

.pi-avatar {
  display: grid;
  width: 82px;
  height: 82px;
  margin-bottom: 24px;
  place-items: center;
  border-radius: 50%;
  color: var(--pku-red-deep);
  background: var(--gold);
  font-size: 34px;
  font-weight: 900;
}

.pi-card h3 {
  margin: 8px 0 16px;
  font-size: 34px;
}

.pi-card p {
  color: rgba(255, 255, 255, 0.76);
}

.pi-card a {
  color: var(--white);
  font-weight: 900;
}

.student-card,
.culture-grid article,
.join-panel {
  padding: clamp(26px, 4vw, 44px);
}

.student-card h3,
.culture-grid h3 {
  margin: 0 0 12px;
  font-size: 28px;
}

.join-panel {
  max-width: 840px;
}

.join-panel a {
  margin-top: 18px;
}

.site-footer {
  display: grid;
  grid-template-columns: minmax(280px, 1fr) minmax(360px, 1.15fr) minmax(300px, 0.9fr);
  gap: clamp(28px, 4vw, 64px);
  align-items: center;
  padding: clamp(22px, 2.4vw, 34px) clamp(24px, 8vw, 150px);
  color: rgba(255, 255, 255, 0.86);
  background:
    linear-gradient(135deg, rgba(12, 17, 22, 0.98), rgba(31, 35, 38, 0.96)),
    radial-gradient(circle at 18% 18%, rgba(47, 140, 140, 0.18), transparent 34%);
  border-top: 4px solid rgba(140, 0, 11, 0.72);
}

.footer-brand {
  display: flex;
  align-items: center;
  gap: 18px;
  min-width: 0;
}

.footer-brand img {
  width: 64px;
  height: 64px;
  flex: 0 0 64px;
  border-radius: 50%;
  background: var(--white);
  box-shadow: 0 0 0 1px rgba(255, 255, 255, 0.22), 0 18px 40px rgba(0, 0, 0, 0.26);
  object-fit: cover;
}

.footer-brand strong,
.footer-brand small {
  display: block;
}

.footer-brand strong {
  color: var(--white);
  font-size: clamp(21px, 2.1vw, 28px);
  line-height: 1.2;
  letter-spacing: 0;
  white-space: nowrap;
}

.footer-brand small {
  margin-top: 6px;
  color: rgba(255, 255, 255, 0.72);
  font-size: 15px;
}

.footer-contact {
  display: grid;
  gap: 6px;
  margin: 0;
  font-style: normal;
}

.footer-contact p {
  display: grid;
  grid-template-columns: auto minmax(0, 1fr);
  gap: 4px;
  margin: 0;
  color: rgba(255, 255, 255, 0.82);
  line-height: 1.65;
}

.footer-contact span {
  color: rgba(255, 255, 255, 0.58);
  font-weight: 800;
}

.footer-contact em {
  min-width: 0;
  font-style: normal;
  overflow-wrap: anywhere;
}

.footer-copy {
  display: block !important;
  margin-top: 8px !important;
  color: rgba(255, 255, 255, 0.46) !important;
  font-size: 13px;
}

.footer-qrs {
  display: flex;
  justify-content: flex-end;
  gap: 22px;
}

.footer-qrs figure {
  display: grid;
  justify-items: center;
  gap: 10px;
  margin: 0;
  color: rgba(255, 255, 255, 0.86);
  text-align: center;
  font-size: 14px;
  font-weight: 800;
}

.footer-qrs img,
.qr-placeholder {
  width: 92px;
  height: 92px;
  border: 8px solid var(--white);
  border-radius: 2px;
  background: var(--white);
  object-fit: cover;
  box-shadow: 0 16px 34px rgba(0, 0, 0, 0.28);
}

.qr-placeholder {
  position: relative;
  background:
    linear-gradient(90deg, #111 10px, transparent 10px 18px, #111 18px 28px, transparent 28px 40px, #111 40px 48px, transparent 48px),
    linear-gradient(#111 10px, transparent 10px 18px, #111 18px 28px, transparent 28px 40px, #111 40px 48px, transparent 48px),
    var(--white);
  background-size: 58px 58px;
}

.qr-placeholder::after {
  content: "LAB";
  position: absolute;
  inset: 50% auto auto 50%;
  display: grid;
  width: 44px;
  height: 44px;
  place-items: center;
  border-radius: 50%;
  color: var(--white);
  background: var(--pku-red-deep);
  font-size: 12px;
  font-weight: 900;
  transform: translate(-50%, -50%);
}

.reveal {
  opacity: 0;
  transform: translateY(26px);
  transition: opacity 720ms ease, transform 720ms cubic-bezier(0.22, 1, 0.36, 1);
  transition-delay: var(--delay, 0ms);
}

.reveal.is-visible {
  opacity: 1;
  transform: translateY(0);
}

@media (max-width: 1180px) {
  #culture.is-active {
    display: block;
    width: 100%;
    max-width: 100%;
    margin-left: 0;
  }

  #culture > .culture-month-switcher {
    position: sticky;
    left: auto;
    width: 100%;
    margin: 18px 0 28px;
  }

  #culture > .culture-empty,
  #culture > .culture-showcase {
    transform: none;
  }

  .site-header {
    grid-template-columns: 1fr auto auto;
  }

  .header-tools {
    display: contents;
  }

  .lang-switch {
    grid-column: 2 / 3;
    align-self: center;
    justify-self: center;
  }

  .school-link {
    position: fixed;
    top: calc(var(--header-height) + 378px);
    left: 0;
    right: 0;
    z-index: 82;
    display: none;
    height: 54px;
    justify-content: center;
    border: 0;
    border-radius: 0;
    color: var(--ink);
    background: rgba(244, 242, 236, 0.98);
    border-bottom: 1px solid var(--line);
  }

  .site-nav {
    position: fixed;
    top: var(--header-height);
    left: 0;
    right: 0;
    display: grid;
    color: var(--ink);
    background: rgba(244, 242, 236, 0.98);
    box-shadow: var(--shadow);
    transform: translateY(-130%);
    opacity: 0;
    pointer-events: none;
    transition: transform 260ms ease, opacity 260ms ease;
  }

  .site-nav.is-open {
    transform: translateY(0);
    opacity: 1;
    pointer-events: auto;
  }

  body.nav-open .school-link {
    display: inline-flex;
  }

  .site-nav a {
    min-height: 54px;
    color: var(--ink);
    border-left: 0;
    border-bottom: 1px solid var(--line);
  }

  .nav-member,
  .nav-achievement,
  .nav-news {
    display: block;
  }

  .nav-member::before,
  .nav-achievement::before,
  .nav-news::before,
  .member-dropdown,
  .achievement-dropdown,
  .news-dropdown {
    display: none;
  }

  .achievement-dropdown,
  .news-dropdown {
    position: static;
    display: grid;
    grid-template-columns: 1fr;
    min-width: 0;
    padding: 0;
    border: 0;
    border-radius: 0;
    background: rgba(244, 242, 236, 0.98);
    box-shadow: none;
    opacity: 1;
    pointer-events: auto;
    transform: none;
    backdrop-filter: none;
  }

  .achievement-dropdown::before,
  .achievement-dropdown::after,
  .news-dropdown::before,
  .news-dropdown::after {
    display: none;
  }

  .achievement-dropdown button,
  .news-dropdown button {
    min-height: 48px;
    border-bottom: 1px solid var(--line);
    background: rgba(23, 27, 29, 0.025);
    font-size: 15px;
  }

  .nav-toggle {
    display: block;
    grid-column: 3 / 4;
  }

  .brand {
    grid-column: 1 / 2;
  }
}

@media (max-width: 900px) {
  .site-header {
    top: 12px;
    grid-template-columns: 1fr auto auto;
    width: calc(100% - 24px);
    min-height: 74px;
  }

  .site-header.is-docked {
    top: 0;
    width: 100%;
  }

  .brand {
    padding: 12px 14px;
  }

  .brand-emblem {
    width: 46px;
    height: 46px;
    flex-basis: 46px;
  }

  .brand-copy strong {
    font-size: 16px;
  }

  .brand-copy small {
    display: none;
  }

  .lang-switch {
    min-width: 80px;
    padding: 0 10px;
  }

  .cover-content {
    width: calc(100% - 36px);
    margin: 0 auto;
  }

  .cover h1 {
    font-size: clamp(30px, 8vw, 48px);
  }

  .cover-lede {
    font-size: clamp(17px, 4.4vw, 24px);
  }

  .home-hero,
  .home-lab-layout,
  .people-layout,
  .member-layout,
  .achievement-layout,
  .advisor-profile,
  .culture-showcase {
    grid-template-columns: 1fr;
  }

  .home-grid,
  .research-cards,
  .culture-grid,
  .news-line,
  .member-card-grid {
    grid-template-columns: 1fr;
  }

  .member-sidebar {
    position: static;
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }

  .advisor-photo {
    width: min(240px, 100%);
  }

  .advisor-info dl div {
    grid-template-columns: 1fr;
    gap: 4px;
  }

  #culture.is-active {
    display: block;
    width: 100%;
    max-width: 100%;
    margin-left: 0;
  }

  .academic-news-layout {
    grid-template-columns: 1fr;
  }

  .news-archive {
    position: static;
    order: -1;
  }

  .news-year-list {
    grid-template-columns: repeat(5, minmax(0, 1fr));
    gap: 0 8px;
  }

  .news-year-list button {
    text-align: center;
  }

  .news-year-list button:hover,
  .news-year-list button.is-active {
    padding-left: 4px;
  }

  .culture-showcase {
    min-height: 0;
    padding: 18px 0;
  }

  .culture-month-switcher {
    top: 74px;
    width: 100%;
    margin-top: 18px;
    overflow: visible;
  }

  .culture-month-grid {
    grid-template-columns: repeat(4, minmax(0, 1fr));
  }

  .culture-carousel {
    width: 100%;
    margin-left: 0;
  }

  .culture-story {
    min-height: 0;
    margin-left: 0;
  }

  .culture-story-head,
  .culture-story-body {
    padding: 30px 24px;
  }

  .culture-story-body {
    gap: 36px;
  }

  .achievement-switcher {
    position: static;
  }

  .achievement-heading {
    align-items: flex-start;
    flex-direction: column;
  }

  .paper-card,
  .patent-card {
    grid-template-columns: 1fr;
  }

  .paper-card.has-image {
    grid-template-columns: 1fr;
  }

  .paper-card dd {
    white-space: normal;
    overflow: visible;
    text-overflow: clip;
  }

  .paper-figure img {
    height: 180px;
  }

  .paper-year-filter {
    grid-template-columns: repeat(5, minmax(0, 1fr));
  }

  .paper-year-filter button:nth-child(5n + 1)::before {
    display: none;
  }

  .paper-search-grid {
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }

  .paper-search label {
    grid-template-columns: 1fr;
    gap: 5px;
  }

  .paper-search button {
    width: 100%;
  }

  .paper-card dl,
  .patent-card dl {
    grid-template-columns: 1fr;
  }

  .alumni-card {
    grid-template-columns: 1fr;
    border-radius: 14px;
  }

  .alumni-portrait {
    width: 104px;
    border-radius: 28px;
  }

  .alumni-head {
    align-items: flex-start;
    flex-direction: column;
    gap: 8px;
  }

  .alumni-card dl {
    grid-template-columns: 1fr;
  }

  .alumni-timeline {
    display: grid;
  }

  .content-shell {
    padding-top: 72px;
  }

  .site-footer {
    grid-template-columns: 1fr;
    align-items: start;
    padding: 38px 22px;
  }

  .footer-brand {
    align-items: flex-start;
  }

  .footer-brand img {
    width: 68px;
    height: 68px;
    flex-basis: 68px;
  }

  .footer-brand strong {
    white-space: normal;
  }

  .footer-contact p {
    grid-template-columns: 1fr;
    gap: 0;
  }

  .footer-qrs {
    width: 100%;
    justify-content: flex-start;
    flex-wrap: wrap;
  }

  .footer-qrs img,
  .qr-placeholder {
    width: 112px;
    height: 112px;
  }
}

@media (max-width: 560px) {
  .news-year-list {
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }

  .paper-year-filter {
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }

  .paper-year-filter button:nth-child(odd)::before {
    display: none;
  }

  .paper-search-grid {
    grid-template-columns: 1fr;
  }
}

@media (prefers-reduced-motion: reduce) {
  *,
  *::before,
  *::after {
    scroll-behavior: auto !important;
    transition-duration: 0.01ms !important;
    animation-duration: 0.01ms !important;
  }

  .site-header,
  .reveal {
    opacity: 1;
    transform: none;
  }
}