:root {
  color-scheme: light;
  --bg: #ffffff;
  --surface: #fffdfa;
  --text: #4b4f54;
  --muted: #6b7076;
  --line: #e7ebf4;
  --neutral-line: #e7e7e7;
  --accent: #8798bf;
  --accent-dark: #6d80ad;
  --rust: #8a4d3a;
  --gold: #7a8791;
  --max: 1120px;
}

* {
  box-sizing: border-box;
}

html {
  scroll-behavior: smooth;
}

body {
  margin: 0;
  background: var(--bg);
  color: var(--text);
  font-family: "Nunito Sans", "Helvetica Neue", Arial, sans-serif;
  font-size: 17px;
  line-height: 1.62;
}

body.modal-open {
  overflow: hidden;
}

a {
  color: var(--accent-dark);
  text-decoration-thickness: 1px;
  text-underline-offset: 0.18em;
}

a:hover,
a:focus {
  color: var(--rust);
}

.site-header {
  position: sticky;
  top: 0;
  z-index: 10;
  border-bottom: 1px solid var(--neutral-line);
  background: rgba(255, 255, 255, 0.92);
  backdrop-filter: blur(12px);
}

.nav {
  display: flex;
  align-items: center;
  justify-content: space-between;
  width: min(100% - 32px, var(--max));
  min-height: 64px;
  margin: 0 auto;
  gap: 24px;
}

.brand {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  color: var(--text);
  font-size: 1.02rem;
  font-weight: 600;
  letter-spacing: 0;
  text-decoration: none;
  white-space: nowrap;
}

.brand img {
  display: block;
  width: 42px;
  height: 42px;
  object-fit: contain;
}

.brand span {
  display: inline-block;
}

.brand:hover span,
.brand:focus span {
  color: var(--accent-dark);
}

.nav-links {
  display: flex;
  align-items: center;
  gap: 18px;
  color: var(--muted);
  font-size: 0.98rem;
}

.nav-links a {
  color: inherit;
  text-decoration: none;
}

.nav-links a:hover,
.nav-links a:focus,
.nav-links a[aria-current="page"] {
  color: var(--accent-dark);
}

.nav-links a[aria-current="page"] {
  font-weight: 700;
}

main {
  width: min(100% - 32px, var(--max));
  margin: 0 auto;
}

.hero {
  display: grid;
  grid-template-columns: 230px minmax(0, 1fr);
  align-items: start;
  gap: clamp(34px, 7vw, 76px);
  padding: 46px 0 16px;
}

.page-head {
  padding: clamp(42px, 7vw, 76px) 0 34px;
  border-bottom: 1px solid var(--line);
}

.page-head.compact {
  border-bottom: 0;
  padding: 18px 0;
}

.eyebrow {
  margin: 0 0 20px;
  color: var(--muted);
  font-size: 0.92rem;
  font-weight: 700;
  letter-spacing: 0.04em;
  text-transform: uppercase;
}

h1,
h2,
h3 {
  margin: 0;
  line-height: 1.12;
  letter-spacing: 0;
}

h1 {
  max-width: 800px;
  font-size: clamp(2.6rem, 6vw, 4rem);
  font-weight: 700;
}

.intro {
  max-width: 780px;
  margin: 14px 0 0;
  color: var(--text);
  font-size: 1.05rem;
  line-height: 1.68;
  hyphens: auto;
  text-align: justify;
}

.intro:first-of-type {
  margin-top: 0;
}

.intro a {
  color: var(--text);
  font-weight: 700;
  text-decoration: none;
}

.intro a:hover,
.intro a:focus {
  color: var(--accent-dark);
}

.text-highlight {
  background: linear-gradient(transparent 58%, #dfe7f5 58%);
  padding: 0 2px;
}

.portrait-wrap {
  display: grid;
  align-content: start;
  justify-items: center;
  gap: 12px;
  text-align: center;
}

.portrait {
  width: 184px;
  height: 184px;
  object-fit: cover;
  object-position: center 28%;
  border: 1px solid var(--neutral-line);
  border-radius: 50%;
  background: var(--surface);
}

.profile-name {
  margin: 4px 0 0;
  color: var(--text);
  font-size: 1.2rem;
  font-weight: 700;
  line-height: 1.2;
  background: linear-gradient(transparent 52%, #dfe7f5 52%);
  padding: 0 2px;
}

.affiliation {
  margin: 0;
  color: var(--muted);
  font-size: 0.95rem;
  line-height: 1.45;
}

.contact-icons {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 12px;
  margin-top: 6px;
}

.contact-icons a {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 24px;
  height: 24px;
}

.contact-icons img {
  display: block;
  max-width: 100%;
  max-height: 100%;
  object-fit: contain;
  opacity: 0.78;
  transition: opacity 160ms ease, transform 160ms ease;
}

.contact-icons a:hover img,
.contact-icons a:focus img {
  opacity: 1;
  transform: translateY(-1px);
}

.section {
  padding: 24px 0 38px;
  scroll-margin-top: 76px;
}

.section h2 {
  margin-bottom: 20px;
  padding-bottom: 12px;
  border-bottom: 1px solid var(--line);
  color: var(--accent-dark);
  font-size: clamp(1.16rem, 1.8vw, 1.38rem);
  font-weight: 700;
  line-height: 1.18;
}

.section-note {
  color: var(--muted);
  font-size: 0.88rem;
  font-weight: 400;
}

.content-stack {
  display: grid;
  gap: 14px;
}

.lead {
  max-width: 820px;
  margin: 0;
  color: var(--text);
  font-size: 1.02rem;
  line-height: 1.72;
}

.tabs {
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
  margin: 0;
}

.tabs a {
  display: inline-flex;
  align-items: center;
  min-height: 34px;
  border: 1px solid var(--line);
  border-radius: 4px;
  padding: 0 14px;
  color: var(--text);
  font-size: 1.02rem;
  font-weight: 700;
  text-decoration: none;
}

.tabs a:hover,
.tabs a:focus {
  border-color: var(--accent);
  color: var(--accent-dark);
}

.publication-head {
  padding: 22px 0 16px;
}

.publication-head h1 {
  color: #17191c;
  font-size: clamp(1.48rem, 2.6vw, 1.9rem);
  font-weight: 700;
  line-height: 1.1;
}

.publication-tabs {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: clamp(6px, 1.5vw, 14px);
  margin-top: 18px;
}

.publication-tabs a {
  display: inline-flex;
  align-items: center;
  min-height: 32px;
  border-radius: 6px;
  padding: 0 12px;
  color: #191b1f;
  font-size: clamp(0.9rem, 1.3vw, 1.02rem);
  font-weight: 400;
  text-decoration: none;
}

.publication-tabs a[aria-current="page"] {
  background: #eef2f8;
  color: var(--accent-dark);
  font-weight: 700;
}

.publication-tabs a:hover,
.publication-tabs a:focus {
  color: var(--accent-dark);
}

.tags {
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
  margin: 8px 0 0;
  padding: 0;
  list-style: none;
}

.tags li {
  border: 0;
  border-radius: 0;
  background: transparent;
  color: var(--accent-dark);
  padding: 0;
  font-size: 1.03rem;
  font-weight: 700;
  line-height: 1.2;
}

.intro-tags {
  gap: 14px;
  margin: 0 0 18px;
}

.item {
  display: flex;
  flex-wrap: wrap;
  align-items: baseline;
  column-gap: 7px;
  row-gap: 4px;
  padding-left: 28px;
  position: relative;
}

.item::before {
  position: absolute;
  top: 0.42em;
  left: 2px;
  color: var(--text);
  content: "•";
  font-size: 1.35rem;
  line-height: 1;
}

.item h3 {
  display: inline;
  color: var(--text);
  font-size: 1.03rem;
  font-weight: 700;
  line-height: 1.48;
}

.meta {
  color: var(--muted);
  font-size: 0.98rem;
}

.date {
  color: var(--text);
  font-size: 1.03rem;
  font-style: italic;
  font-weight: 700;
  white-space: nowrap;
}

.item > .date {
  display: inline;
  order: -1;
}

.item > .date::after {
  content: ": ";
}

.item > div:not(.date) {
  flex: 1 1 520px;
}

.details {
  margin: 7px 0 0;
  color: var(--muted);
}

.patent-item {
  color: var(--text);
}

.patent-item.has-logo {
  display: grid;
  grid-template-columns: 34px minmax(0, 1fr);
  column-gap: 10px;
  align-items: start;
}

.patent-item.has-logo .patent-heading,
.patent-item.has-logo .patent-title-cont,
.patent-item.has-logo .patent-application {
  grid-column: 2;
}

.patent-heading,
.patent-title-cont,
.patent-application {
  margin: 0;
  font-size: 1.03rem;
  line-height: 1.48;
}

.patent-hanyang-logo {
  transform: translateY(-3px);
}

.patent-application {
  color: var(--muted);
  margin-top: 2px;
}

.experience-item {
  color: var(--text);
}

.experience-item.has-logo {
  display: grid;
  grid-template-columns: 34px minmax(0, 1fr);
  column-gap: 10px;
  align-items: start;
}

.experience-logo {
  align-self: center;
  grid-column: 1;
  grid-row: 1;
  width: 30px;
  height: 30px;
  object-fit: contain;
  transform: translateY(-3px);
}

.experience-heading {
  margin: 0;
  font-size: 1.03rem;
  line-height: 1.48;
}

.experience-item.has-logo .experience-heading,
.experience-item.has-logo .experience-role,
.experience-item.has-logo .experience-detail {
  grid-column: 2;
}

.experience-heading strong {
  font-weight: 700;
}

.experience-role {
  margin: 6px 0 0;
  color: var(--text);
  font-size: 1rem;
  line-height: 1.48;
}

.experience-role::before {
  content: "◦";
  margin-right: 8px;
}

.experience-detail {
  margin: 4px 0 0 24px;
  color: var(--muted);
  font-size: 0.98rem;
  line-height: 1.48;
}

.publication {
  column-gap: 8px;
  display: grid;
  grid-template-columns: 34px minmax(0, 1fr);
  position: relative;
  row-gap: 2px;
}

.publication::before {
  content: none;
}

.publication h3 {
  display: contents;
  max-width: none;
  color: var(--text);
  font-size: 0.96rem;
  font-weight: 700;
  line-height: 1.48;
}

.pub-index {
  color: var(--text);
  grid-column: 1;
  font-weight: 700;
  line-height: 1.48;
}

.pub-title {
  grid-column: 2;
  line-height: 1.48;
}

.publication .authors,
.publication .venue,
.publication .status,
.publication .note,
.publication .links {
  grid-column: 2;
}

.authors,
.venue,
.status,
.note,
.links {
  margin: 2px 0 0;
  color: var(--muted);
  font-size: 0.98rem;
}

.note {
  color: var(--accent-dark);
  font-weight: 700;
}

.me {
  color: var(--text);
  font-weight: 700;
  text-decoration: underline;
  text-underline-offset: 0.16em;
}

.links {
  display: flex;
  flex-wrap: wrap;
  gap: 0;
  align-items: center;
}

.links::before {
  display: inline-block;
  width: 0.95em;
  height: 0.95em;
  margin-right: 6px;
  background: url("icons/link.png") center / contain no-repeat;
  content: "";
  opacity: 0.82;
  transform: translateY(-2px);
}

.links a {
  color: var(--text);
  font-weight: 700;
  text-decoration: none;
}

.links a:hover,
.links a:focus {
  color: var(--accent-dark);
}

.links a + a::before {
  color: var(--muted);
  content: "|";
  display: inline-block;
  font-weight: 400;
  margin: 0 8px;
}

.award-list,
.simple-list {
  display: grid;
  gap: 12px;
  margin: 0;
  padding-left: 0;
  list-style: none;
}

.award-list li,
.simple-list li {
  color: var(--text);
  font-size: 1.03rem;
  font-weight: 400;
  line-height: 1.5;
}

.award-list strong,
.simple-list strong {
  font-weight: 700;
}

.service-block h3 {
  margin: 0 0 8px;
  color: var(--text);
  font-size: 1.03rem;
  font-weight: 700;
  line-height: 1.48;
}

.service-list {
  display: grid;
  gap: 6px;
  margin: 0;
  padding-left: 0;
  color: var(--text);
  font-size: 1.03rem;
  list-style: none;
  line-height: 1.48;
}

.service-list li::before {
  content: "◦";
  margin-right: 8px;
}

.project-item {
  display: grid;
  grid-template-columns: 250px minmax(0, 1fr);
  gap: 20px;
  align-items: start;
}

.project-item + .project-item {
  margin-top: 18px;
}

.project-image {
  width: 100%;
  aspect-ratio: 16 / 10;
  border: 1px solid var(--neutral-line);
  border-radius: 8px;
  object-fit: cover;
}

.project-body h3 {
  margin: 0;
  color: var(--text);
  font-size: 1.12rem;
  font-weight: 700;
  line-height: 1.35;
}

.project-body {
  padding-top: 0;
}

.project-description {
  min-height: 5.2em;
  margin: 10px 0 0;
  color: var(--muted);
  font-size: 1rem;
  line-height: 1.56;
}

.project-output {
  margin: 8px 0 0;
  color: var(--text);
  font-size: 1rem;
  line-height: 1.48;
}

.project-output strong {
  display: inline-flex;
  align-items: center;
  min-height: 24px;
  padding: 2px 8px;
  border-radius: 6px;
  background: #eee8f8;
  color: var(--text);
  font-size: 0.86rem;
  font-weight: 700;
  line-height: 1;
}

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

.project-paper-button {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  min-height: 30px;
  padding: 0 14px;
  border: 1px solid var(--line);
  border-radius: 999px;
  background: #ffffff;
  color: var(--accent-dark);
  box-shadow: 0 4px 12px rgba(35, 38, 48, 0.06);
  cursor: pointer;
  font: inherit;
  font-size: 0.84rem;
  font-weight: 700;
  letter-spacing: 0.01em;
  line-height: 1;
  text-decoration: none;
  transition: border-color 160ms ease, color 160ms ease, transform 160ms ease, box-shadow 160ms ease;
}

.project-paper-button:hover,
.project-paper-button:focus {
  border-color: var(--accent);
  color: var(--accent);
  box-shadow: 0 8px 18px rgba(35, 38, 48, 0.1);
  text-decoration: none;
  transform: translateY(-1px);
}

a.project-paper-button,
a.project-paper-button:hover,
a.project-paper-button:focus,
a.project-paper-button:visited {
  text-decoration: none;
}

.paper-modal {
  position: fixed;
  inset: 0;
  z-index: 40;
  display: grid;
  place-items: center;
  padding: 32px;
  opacity: 0;
  pointer-events: none;
  transition: opacity 180ms ease;
}

.paper-modal.is-open {
  opacity: 1;
  pointer-events: auto;
}

.paper-modal-backdrop {
  position: absolute;
  inset: 0;
  background: rgba(26, 28, 34, 0.36);
}

.paper-modal-panel {
  position: relative;
  z-index: 1;
  display: flex;
  flex-direction: column;
  width: min(920px, 100%);
  max-height: min(82vh, 760px);
  overflow: hidden;
  border: 1px solid var(--neutral-line);
  border-radius: 10px;
  background: #fff;
  padding: 30px 34px 34px;
  box-shadow: 0 24px 70px rgba(35, 38, 48, 0.22);
}

.paper-modal-panel h2 {
  flex: 0 0 auto;
  margin: 0 0 24px;
  border-bottom: 1px solid var(--neutral-line);
  padding: 0 0 12px;
  color: var(--text);
}

.paper-modal-body {
  overflow-y: auto;
  padding-right: 10px;
  scrollbar-color: #c5c5c5 transparent;
  scrollbar-width: thin;
}

.paper-modal-body::-webkit-scrollbar {
  width: 8px;
}

.paper-modal-body::-webkit-scrollbar-track {
  background: transparent;
  border: 0;
}

.paper-modal-body::-webkit-scrollbar-thumb {
  border-radius: 999px;
  background: #c5c5c5;
}

.paper-modal-group + .paper-modal-group {
  margin-top: 28px;
}

.paper-modal-group > h3 {
  margin: 0 0 16px;
  color: var(--accent-dark);
  font-size: 1.02rem;
  font-weight: 700;
}

.paper-modal-group .content-stack {
  border-top: 0;
  padding-top: 0;
}

.paper-modal .note {
  color: var(--muted);
  font-weight: 700;
}

.paper-modal .patent-item {
  margin-top: 2px;
}

.demo-modal-panel {
  width: min(860px, 100%);
}

.demo-video {
  display: block;
  width: 100%;
  max-height: 62vh;
  border: 1px solid var(--neutral-line);
  border-radius: 8px;
  background: #000;
}

.demo-link {
  margin: 0 0 12px;
  font-size: 0.98rem;
  font-weight: 700;
}

.demo-link a {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  color: var(--text);
  text-decoration: none;
}

.demo-link img {
  width: 1.05em;
  height: 1.05em;
  object-fit: contain;
}

.demo-link a:hover,
.demo-link a:focus {
  color: var(--accent-dark);
}

.paper-modal-close {
  position: absolute;
  top: 24px;
  right: 35px;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 30px;
  height: 30px;
  border: 1px solid var(--neutral-line);
  border-radius: 50%;
  background: #fff;
  color: var(--muted);
  cursor: pointer;
  font: inherit;
  font-size: 1.25rem;
  font-weight: 700;
  line-height: 1;
}

.paper-modal-close:hover,
.paper-modal-close:focus {
  border-color: var(--accent);
  color: var(--accent-dark);
}

.footer {
  width: min(100% - 32px, var(--max));
  margin: 0 auto;
  padding: 36px 0 52px;
  color: var(--muted);
  font-size: 0.92rem;
}

.to-top {
  position: fixed;
  right: 60px;
  bottom: 56px;
  z-index: 20;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 42px;
  height: 42px;
  border: 1px solid var(--neutral-line);
  border-radius: 50%;
  background: rgba(255, 255, 255, 0.94);
  color: var(--accent-dark);
  box-shadow: 0 10px 24px rgba(35, 38, 48, 0.12);
  cursor: pointer;
  font: inherit;
  font-size: 1.35rem;
  font-weight: 700;
  line-height: 1;
  opacity: 0;
  pointer-events: none;
  transform: translateY(8px);
  transition: opacity 180ms ease, transform 180ms ease, color 160ms ease, border-color 160ms ease;
}

.to-top.is-visible {
  opacity: 1;
  pointer-events: auto;
  transform: translateY(0);
}

.to-top:hover,
.to-top:focus {
  border-color: var(--accent);
  color: var(--accent);
}

@media (max-width: 840px) {
  .nav {
    align-items: flex-start;
    flex-direction: column;
    gap: 8px;
    padding: 14px 0;
  }

  .nav-links {
    width: 100%;
    gap: 12px;
    overflow-x: auto;
    padding-bottom: 2px;
  }

  .hero {
    grid-template-columns: 1fr;
    padding-top: 44px;
  }

  .portrait-wrap {
    max-width: 320px;
  }

  .section {
    padding: 44px 0;
  }

  .item,
  .award-list li,
  .simple-list li {
    gap: 5px 8px;
  }

  .date {
    white-space: normal;
  }

  .publication {
    column-gap: 6px;
    grid-template-columns: 30px minmax(0, 1fr);
  }

  .project-item {
    grid-template-columns: 1fr;
  }

  .paper-modal {
    padding: 18px;
  }

  .paper-modal-panel {
    padding: 26px 20px 28px;
  }
}

@media (max-width: 520px) {
  .to-top {
    right: 28px;
    bottom: 28px;
  }

  main,
  .footer,
  .nav {
    width: min(100% - 24px, var(--max));
  }

  h1 {
    font-size: 3rem;
  }
}