:root {
  --crimson: #8b0029;
  --text: #333333;
  --muted: #686868;
  --light: #f7f7f7;
  --border: #dddddd;
  --container: 1200px;
}

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

html {
  scroll-behavior: smooth;
}

body {
  background: #ffffff;
  color: var(--text);
  font-family: "Inter", -apple-system, BlinkMacSystemFont, "Segoe UI", sans-serif;
  font-size: 15px;
  line-height: 1.65;
  -webkit-font-smoothing: antialiased;
}

a {
  color: inherit;
  text-decoration: none;
}

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

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

.skip-link {
  position: fixed;
  left: 16px;
  top: -60px;
  z-index: 1000;
  padding: 10px 14px;
  background: var(--crimson);
  color: #ffffff;
}

.skip-link:focus {
  top: 16px;
}

.site-header {
  position: sticky;
  top: 0;
  z-index: 100;
  background: #ffffff;
  border-bottom: 1px solid var(--border);
}

.nav-container {
  max-width: var(--container);
  height: 80px;
  margin: 0 auto;
  padding: 0 24px;
  display: flex;
  align-items: center;
  justify-content: space-between;
}

.brand {
  display: inline-flex;
  align-items: center;
  gap: 9px;
}

.brand-mark {
  width: 66px;
  height: 66px;
  display: grid;
  place-items: center;
  background: #ffffff;
}

.brand-mark img {
  position: static;
  width: 66px;
  height: 66px;
  object-fit: contain;
}

.brand-text {
  display: flex;
  flex-direction: column;
  line-height: 1.15;
}

.brand-text strong {
  color: #222222;
  font-size: 18px;
  font-weight: 600;
}

.brand-text small {
  margin-top: 5px;
  color: #777777;
  font-size: 8px;
  letter-spacing: 0.16em;
  text-transform: uppercase;
}

.nav-menu {
  display: flex;
  align-items: center;
  gap: 6px;
}

.nav-link {
  padding: 8px 12px;
  border-radius: 4px;
  color: #606060;
  font-size: 14px;
  transition: background-color 160ms ease, color 160ms ease;
}

.nav-link:hover,
.nav-link.active {
  background: #f3f3f3;
  color: #222222;
}

.nav-toggle {
  display: none;
}

.home-hero {
  position: relative;
  isolation: isolate;
  overflow: hidden;
  min-height: 445px;
  padding-top: 130px;
  padding-bottom: 105px;
  background:
    radial-gradient(circle at 14% 20%, rgba(139, 0, 41, 0.08), transparent 30%),
    radial-gradient(circle at 86% 78%, rgba(139, 0, 41, 0.055), transparent 32%),
    linear-gradient(135deg, #ffffff 0%, #fcf9fa 48%, #f7f7f7 100%);
  text-align: center;
}

.home-hero::before,
.home-hero::after {
  content: "";
  position: absolute;
  pointer-events: none;
}

.home-hero::before {
  inset: -48px;
  z-index: 0;
  background-image:
    linear-gradient(rgba(139, 0, 41, 0.038) 1px, transparent 1px),
    linear-gradient(90deg, rgba(139, 0, 41, 0.038) 1px, transparent 1px);
  background-position: 0 0;
  background-size: 52px 52px;
  -webkit-mask-image: radial-gradient(ellipse at center, #000 18%, transparent 72%);
  mask-image: radial-gradient(ellipse at center, #000 18%, transparent 72%);
  animation: hero-grid-drift 22s linear infinite;
}

.home-hero::after {
  inset: -42%;
  z-index: 0;
  background:
    radial-gradient(circle at 32% 48%, rgba(139, 0, 41, 0.10), transparent 20%),
    radial-gradient(circle at 68% 52%, rgba(139, 0, 41, 0.065), transparent 22%);
  filter: blur(18px);
  animation: hero-light-drift 14s ease-in-out infinite alternate;
}

.hero-content {
  position: relative;
  z-index: 1;
}

@keyframes hero-grid-drift {
  to {
    background-position: 52px 52px;
  }
}

@keyframes hero-light-drift {
  from {
    transform: translate3d(-2.5%, -1.5%, 0) scale(1);
  }

  to {
    transform: translate3d(2.5%, 1.5%, 0) scale(1.06);
  }
}

.hero-university {
  margin-bottom: 10px;
  color: #555555;
  font-size: 34px;
  font-weight: 700;
  letter-spacing: 0.06em;
  text-transform: uppercase;
}

.home-hero h1 {
  color: #111111;
  font-size: clamp(48px, 5.4vw, 76px);
  font-weight: 700;
  letter-spacing: -0.035em;
  line-height: 1.12;
}

.home-hero h1 span {
  color: var(--crimson);
}

.hero-subtitle {
  margin-top: 22px;
  color: #777777;
  font-size: 16px;
}

.intro-section {
  padding: 70px 0;
  border-top: 1px solid #eeeeee;
  background: #ffffff;
}

.intro-layout {
  display: grid;
  grid-template-columns: 330px 1fr;
  gap: 70px;
  align-items: center;
}

.intro-logo {
  display: flex;
  justify-content: center;
}

.intro-logo img {
  width: 300px;
}

.intro-copy {
  max-width: 760px;
  color: #454545;
  font-size: 16px;
}

.intro-copy p {
  margin-bottom: 18px;
}

.intro-copy h2 {
  margin: 26px 0 10px;
  color: #333333;
  font-size: 16px;
  font-weight: 600;
}

.intro-copy ul {
  margin: 0 0 22px 20px;
}

.intro-copy li {
  margin-bottom: 5px;
}

.intro-copy a,
.contact-copy a {
  color: var(--crimson);
  text-decoration: underline;
  text-underline-offset: 3px;
}

.recruiting-note {
  margin-bottom: 0 !important;
}

.research-page-link {
  margin-bottom: 14px !important;
  font-size: 14px;
  font-weight: 500;
}

.home-news {
  padding: 65px 0 85px;
  border-top: 1px solid #eeeeee;
  background: #fafafa;
}

.section-heading-row {
  margin-bottom: 26px;
  display: flex;
  align-items: center;
  justify-content: space-between;
}

.section-heading-row h2 {
  color: #333333;
  font-size: 27px;
  font-weight: 600;
}

.section-heading-row a {
  color: #666666;
  font-size: 13px;
}

.section-heading-row a:hover {
  color: var(--crimson);
}

.news-list {
  border-top: 1px solid var(--border);
}

.news-row {
  min-height: 78px;
  padding: 20px 4px;
  display: grid;
  grid-template-columns: 105px 1fr;
  gap: 24px;
  align-items: center;
  border-bottom: 1px solid var(--border);
}

.news-row time {
  color: #888888;
  font-size: 13px;
}

.news-row p {
  color: #3e3e3e;
  font-size: 15px;
}

.news-summary {
  color: #3e3e3e !important;
  font-size: 15px !important;
  font-weight: 400;
  line-height: 1.55;
}

.news-summary strong {
  color: #111111;
  font-weight: 700 !important;
}

.news-venue-name {
  padding: 1px 4px;
  border-radius: 2px;
  background: rgba(139, 0, 41, 0.08);
  color: var(--crimson);
  font-weight: 700 !important;
  white-space: nowrap;
}

.site-footer {
  padding: 42px 0 24px;
  border-top: 1px solid #e5e5e5;
  background: #f5f5f5;
  color: #696969;
}

.footer-content {
  display: flex;
  align-items: flex-end;
  justify-content: space-between;
  gap: 40px;
}

.footer-content h2 {
  margin-bottom: 6px;
  color: #3d3d3d;
  font-size: 16px;
  font-weight: 600;
}

.footer-content p {
  font-size: 13px;
}

.copyright {
  color: #888888;
  font-size: 12px !important;
}

.page-header {
  padding: 52px 0 38px;
  border-bottom: 1px solid #eeeeee;
  background: #fafafa;
}

.page-header h1 {
  color: #333333;
  font-size: 36px;
  font-weight: 600;
}

.page-header p {
  margin-top: 6px;
  color: #777777;
}

.page-content {
  min-height: 520px;
  padding-top: 60px;
  padding-bottom: 90px;
}

.blank-page {
  min-height: 650px;
}

.people-section {
  padding: 50px 0;
}

.people-category {
  margin-bottom: 50px;
}

.category-title {
  margin-bottom: 30px;
  padding-bottom: 10px;
  border-bottom: 2px solid var(--crimson);
  color: #333333;
  font-size: 24px;
  font-weight: 600;
}

.section-header {
  margin-bottom: 30px;
}

.current-members-header {
  margin-top: 60px;
}

.section-title {
  margin-bottom: 25px;
  padding-bottom: 10px;
  border-bottom: 2px solid var(--crimson);
  color: #333333;
  font-size: 24px;
  font-weight: 600;
  text-align: center;
}

.people-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(300px, 1fr));
  gap: 30px;
}

.person-card {
  padding: 20px;
  border: 1px solid #eeeeee;
  border-radius: 8px;
  background: #ffffff;
  transition: box-shadow 300ms ease;
}

.person-card:hover {
  box-shadow: 0 4px 12px rgba(0, 0, 0, 0.1);
}

.person-photo {
  margin-bottom: 15px;
  text-align: center;
}

.person-img,
.photo {
  width: 150px;
  height: 150px;
  margin: 0 auto;
  border-radius: 50%;
  background: #f0f0f0;
  object-fit: cover;
  object-position: center 24%;
}

.photo-donghwan,
.photo-dongwook {
  object-position: center 27%;
}

.photo-sangyoon {
  object-position: center 20%;
}

.person-name {
  margin-bottom: 5px;
  color: #333333;
  font-size: 18px;
  font-weight: 600;
}

.person-email {
  margin-bottom: 8px;
  font-size: 13px;
}

.person-email a {
  color: var(--crimson);
}

.person-email a:hover {
  text-decoration: underline;
}

.person-education {
  color: #666666;
  font-size: 13px;
  line-height: 1.55;
}

.person-detail-pending {
  color: #999999;
}

.person-highlights {
  margin: 2px 0 12px;
  padding-left: 18px;
  color: #666666;
  font-size: 13px;
  line-height: 1.55;
}

.person-highlights li + li {
  margin-top: 2px;
}

.person-links {
  margin-top: 13px;
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
}

.person-link {
  padding: 4px 8px;
  border: 1px solid #dddddd;
  border-radius: 3px;
  color: #666666;
  font-size: 12px;
  transition: background-color 200ms ease, color 200ms ease;
}

.person-link:hover {
  background: #f5f5f5;
  color: #333333;
}

.publication-list-page {
  display: flex;
  flex-direction: column;
}

.publication-controls {
  margin-bottom: 46px;
}

.publication-search {
  position: relative;
  width: min(100%, 520px);
  display: block;
}

.publication-search input {
  width: 100%;
  height: 48px;
  padding: 0 44px 0 18px;
  border: 1px solid #d4d4d4;
  border-radius: 24px;
  background: #fafafa;
  color: #333333;
  font: inherit;
  font-size: 14px;
  outline: none;
  transition: border-color 160ms ease, box-shadow 160ms ease, background 160ms ease;
}

.publication-search input:focus {
  border-color: var(--crimson);
  background: #ffffff;
  box-shadow: 0 0 0 3px rgba(139, 0, 41, 0.08);
}

.publication-search .search-icon {
  position: absolute;
  z-index: 1;
  top: 16px;
  right: 19px;
  width: 14px;
  height: 14px;
  border: 1.5px solid #777777;
  border-radius: 50%;
  pointer-events: none;
}

.publication-search .search-icon::after {
  content: "";
  position: absolute;
  right: -4px;
  bottom: -3px;
  width: 6px;
  height: 1.5px;
  background: #777777;
  transform: rotate(45deg);
}

.publication-filters {
  margin-top: 20px;
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
}

.filter-btn {
  padding: 7px 13px;
  border: 1px solid #d8d8d8;
  border-radius: 4px;
  background: #ffffff;
  color: #666666;
  font-family: inherit;
  font-size: 12px;
  cursor: pointer;
  transition: border-color 160ms ease, background 160ms ease, color 160ms ease;
}

.filter-btn:hover,
.filter-btn.active {
  border-color: var(--crimson);
  background: var(--crimson);
  color: #ffffff;
}

.publication-count {
  margin-top: 16px;
  color: #888888;
  font-size: 12px;
}

.publication-year {
  margin-bottom: 54px;
}

.publication-year > h2 {
  padding-bottom: 10px;
  border-bottom: 2px solid var(--crimson);
  color: #333333;
  font-size: 25px;
  font-weight: 600;
}

.publication-row {
  padding: 28px 0;
  display: grid;
  grid-template-columns: 210px 1fr;
  gap: 34px;
  border-bottom: 1px solid #e2e2e2;
}

.publication-visual {
  width: 210px;
  height: 118px;
  display: grid;
  place-items: center;
  overflow: hidden;
  border: 1px solid #eeeeee;
  background: #f7f7f7;
}

.publication-visual img {
  width: 100%;
  height: 100%;
  object-fit: cover;
}

.publication-placeholder {
  max-width: 170px;
  color: #a3a3a3;
  font-size: 13px;
  font-weight: 600;
  text-align: center;
}

.publication-row h3 {
  margin: 3px 0 8px;
  color: #2e2e2e;
  font-size: 18px;
  font-weight: 600;
  line-height: 1.4;
}

.publication-meta {
  color: var(--crimson);
  font-size: 12px;
  font-weight: 600;
}

.publication-authors {
  margin-bottom: 8px;
  color: #656565;
  font-size: 13px;
}

.publication-venue {
  margin-bottom: 8px;
  color: #777777;
  font-size: 12px;
  font-style: italic;
}

.publication-note {
  margin-bottom: 9px;
  color: var(--crimson);
  font-size: 12px;
}

.publication-links a {
  margin-right: 13px;
  color: #555555;
  font-size: 12px;
  font-weight: 500;
}

.publication-links a:hover {
  color: var(--crimson);
}

.publication-loading,
.publication-empty {
  padding: 50px 20px;
  background: #fafafa;
  color: #777777;
  text-align: center;
}

.clear-publication-search {
  margin-top: 15px;
  padding: 8px 14px;
  border: 1px solid #cccccc;
  border-radius: 4px;
  background: #ffffff;
  color: #444444;
  font: inherit;
  font-size: 12px;
  cursor: pointer;
}

.full-news-list .news-row {
  min-height: 90px;
}

.contact-layout {
  max-width: 800px;
}

.contact-copy {
  margin-bottom: 45px;
}

.contact-copy h2 {
  margin-bottom: 14px;
  color: #333333;
  font-size: 22px;
  font-weight: 600;
}

.contact-copy p {
  margin-bottom: 14px;
}

.contact-copy .join-introduction {
  color: #3f3f3f;
  font-size: 15px;
  line-height: 1.75;
}

.contact-copy h3 {
  margin: 30px 0 12px;
  color: #333333;
  font-size: 18px;
  font-weight: 600;
}

.recruitment-qualities,
.application-materials {
  margin: 0 0 24px;
  padding-left: 22px;
}

.recruitment-qualities li {
  margin-bottom: 18px;
  color: #505050;
  line-height: 1.75;
}

.recruitment-qualities strong {
  color: #303030;
  font-weight: 600;
}

.application-materials li {
  margin-bottom: 7px;
  color: #505050;
}

.application-note {
  margin-bottom: 0 !important;
  color: #666666;
}

.contact-details {
  padding: 24px;
  border: 1px solid #e0e0e0;
  background: #fafafa;
}

.contact-details p + p {
  margin-top: 10px;
}

.location-section {
  margin-top: 58px;
}

.location-section > h2 {
  margin-bottom: 12px;
  color: #333333;
  font-size: 22px;
  font-weight: 600;
}

.location-section > p {
  margin-bottom: 20px;
  color: #555555;
}

.location-map {
  overflow: hidden;
  border: 1px solid #dddddd;
}

.location-map iframe {
  width: 100%;
  display: block;
  border: 0;
}

.research-page {
  max-width: 1100px;
}

.research-introduction {
  max-width: 890px;
  margin-bottom: 70px;
  color: #4a4a4a;
  font-size: 17px;
  line-height: 1.8;
}

.research-introduction p + p {
  margin-top: 18px;
}

.research-introduction .research-thesis {
  margin-bottom: 24px;
  color: #2d2d2d;
  font-size: 27px;
  font-weight: 600;
  line-height: 1.35;
}

.research-directions {
  display: flex;
  flex-direction: column;
  gap: 16px;
}

.research-direction {
  padding: 32px 34px;
  display: grid;
  grid-template-columns: 55px 250px 1fr;
  gap: 30px;
  border: 1px solid #dedede;
  background: #ffffff;
}

.research-direction:nth-child(even) {
  background: #fafafa;
}

.direction-number {
  padding-top: 3px;
  color: var(--crimson);
  font-size: 12px;
  font-weight: 600;
}

.research-direction h2 {
  color: #303030;
  font-size: 20px;
  font-weight: 600;
  line-height: 1.4;
}

.research-direction > div > p:first-child {
  color: #515151;
  line-height: 1.75;
}


@media (max-width: 820px) {
  .nav-toggle {
    width: 36px;
    height: 36px;
    padding: 7px;
    display: flex;
    flex-direction: column;
    justify-content: center;
    gap: 5px;
    border: 0;
    background: transparent;
    cursor: pointer;
  }

  .nav-toggle span {
    width: 100%;
    height: 2px;
    background: #444444;
    transition: transform 160ms ease, opacity 160ms ease;
  }

  .nav-toggle[aria-expanded="true"] span:nth-child(1) { transform: translateY(7px) rotate(45deg); }
  .nav-toggle[aria-expanded="true"] span:nth-child(2) { opacity: 0; }
  .nav-toggle[aria-expanded="true"] span:nth-child(3) { transform: translateY(-7px) rotate(-45deg); }

  .nav-menu {
    position: absolute;
    left: 0;
    right: 0;
    top: 80px;
    padding: 12px 24px 20px;
    display: none;
    align-items: stretch;
    flex-direction: column;
    gap: 2px;
    border-bottom: 1px solid var(--border);
    background: #ffffff;
    box-shadow: 0 10px 22px rgba(0, 0, 0, 0.06);
  }

  .nav-menu.open {
    display: flex;
  }

  .nav-link {
    padding: 11px 12px;
  }

  .intro-layout {
    grid-template-columns: 240px 1fr;
    gap: 38px;
  }

  .intro-logo img {
    width: 230px;
  }

  .research-direction {
    grid-template-columns: 45px 205px 1fr;
    gap: 22px;
  }

  .publication-row {
    grid-template-columns: 180px 1fr;
    gap: 24px;
  }

  .publication-visual {
    width: 180px;
    height: 108px;
  }
}

@media (max-width: 620px) {
  .container,
  .nav-container {
    padding-left: 18px;
    padding-right: 18px;
  }

  .brand-text strong {
    font-size: 17px;
  }

  .home-hero {
    min-height: 390px;
    padding-top: 105px;
    padding-bottom: 85px;
  }

  .hero-university {
    font-size: 23px;
  }

  .home-hero h1 {
    font-size: 46px;
  }

  .hero-subtitle {
    font-size: 13px;
  }

  .intro-section,
  .home-news {
    padding: 55px 0;
  }

  .intro-layout,
  .publication-row {
    grid-template-columns: 1fr;
  }

  .intro-layout {
    gap: 35px;
  }

  .intro-logo img {
    width: 240px;
  }

  .intro-copy {
    font-size: 15px;
  }

  .news-row {
    grid-template-columns: 78px 1fr;
    gap: 12px;
    align-items: start;
  }

  .news-row p {
    font-size: 14px;
  }

  .footer-content {
    align-items: flex-start;
    flex-direction: column;
    gap: 24px;
  }

  .page-header {
    padding: 38px 0 28px;
  }

  .page-header h1 {
    font-size: 29px;
  }

  .page-content {
    padding-top: 42px;
    padding-bottom: 65px;
  }

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

  .publication-row {
    gap: 18px;
  }

  .publication-visual {
    width: 100%;
    height: 180px;
  }

  .publication-search {
    width: 100%;
  }

  .publication-year > h2 {
    font-size: 22px;
  }

  .research-introduction {
    margin-bottom: 52px;
    font-size: 15px;
  }

  .research-introduction .research-thesis {
    font-size: 23px;
  }

  .research-direction {
    padding: 26px 22px;
    grid-template-columns: 32px 1fr;
    gap: 6px 12px;
  }

  .research-direction h2 {
    font-size: 18px;
  }

  .research-direction > div {
    grid-column: 2;
  }

  .location-section {
    margin-top: 46px;
  }

  .location-map iframe {
    height: 280px;
  }
}

@media (prefers-reduced-motion: reduce) {
  html {
    scroll-behavior: auto;
  }

  *,
  *::before,
  *::after {
    animation-duration: 0.01ms !important;
    animation-iteration-count: 1 !important;
    transition-duration: 0.01ms !important;
  }
}