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

html,
body {
  overflow-x: clip;
}

html {
  background: var(--color-paper);
  scroll-behavior: auto;
}

body {
  min-width: 20rem;
  margin: 0;
  background: var(--color-paper);
  color: var(--color-ink);
  font-family: var(--font-body);
  font-size: var(--text-base);
  line-height: 1.6;
  text-rendering: optimizeLegibility;
}

[lang="ko"] body {
  word-break: keep-all;
}

::selection {
  background: var(--color-selection);
  color: var(--color-ink);
}

a {
  color: inherit;
  text-decoration-color: var(--color-rule-strong);
  text-decoration-thickness: var(--rule-hair);
  text-underline-offset: var(--space-2xs);
}

a:hover {
  color: var(--color-accent);
  text-decoration-color: var(--color-accent);
}

a:active {
  color: var(--color-ink);
  text-decoration-thickness: var(--focus-width);
}

a:focus-visible {
  outline: var(--focus-width) solid var(--color-focus);
  outline-offset: var(--space-2xs);
}

a[aria-disabled="true"] {
  color: var(--color-muted);
  cursor: not-allowed;
  pointer-events: none;
  text-decoration: none;
}

.skip-link {
  position: fixed;
  z-index: var(--z-sticky);
  top: var(--space-sm);
  left: var(--space-sm);
  padding: var(--space-sm) var(--space-md);
  background: var(--color-ink);
  color: var(--color-surface);
  font-weight: 700;
  transform: translateY(-200%);
}

.skip-link:focus {
  transform: none;
}

.nav-mast,
.page-shell,
.foot-dense {
  width: min(100%, var(--page-width));
  margin-inline: auto;
  padding-inline: var(--page-gutter);
}

.nav-mast {
  display: grid;
  gap: var(--space-xs);
  padding-top: var(--space-xl);
  text-align: left;
}

.mast-line,
.mast-role {
  margin: 0;
  color: var(--color-muted);
  font-size: var(--text-xs);
  letter-spacing: 0;
}

.mast-line {
  font-weight: 500;
}

.mast-name {
  min-width: 0;
  margin: var(--space-sm) 0 0;
  font-family: var(--font-display);
  font-size: var(--text-3xl);
  font-style: normal;
  font-weight: 800;
  letter-spacing: 0;
  line-height: 1.05;
  overflow-wrap: anywhere;
}

.mast-role {
  font-size: var(--text-sm);
  font-weight: 500;
}

.mast-nav ul {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  justify-content: flex-start;
  gap: 0 var(--space-lg);
  margin: var(--space-sm) 0 0;
  padding: 0;
  list-style: none;
}

.mast-nav a {
  display: inline-flex;
  min-height: 2.75rem;
  align-items: center;
  font-size: var(--text-sm);
  font-weight: 600;
  text-decoration: none;
  white-space: nowrap;
}

.mast-rule {
  height: 0;
  margin: var(--space-sm) 0 0;
  border: 0;
  border-top: var(--rule-hair) solid var(--color-rule-strong);
}

.intro {
  display: grid;
  gap: var(--space-md);
  padding-block: var(--space-2xl) var(--space-3xl);
}

.intro h2,
.section-lead h2,
.contact-section h2 {
  min-width: 0;
  margin: 0;
  font-family: var(--font-display);
  font-style: normal;
  font-weight: 700;
  letter-spacing: 0;
  overflow-wrap: anywhere;
}

.intro h2 {
  max-width: 26ch;
  font-size: var(--text-2xl);
  line-height: 1.16;
}

.intro p {
  max-width: var(--measure);
  margin: 0;
  color: var(--color-muted);
  font-size: var(--text-lg);
  line-height: 1.7;
}

.intro-links,
.contact-links {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: var(--space-sm) var(--space-xl);
}

.intro-links {
  margin-top: var(--space-xs);
}

.text-link,
.ledger-row a {
  font-weight: 600;
  white-space: nowrap;
}

.award-highlight strong {
  color: var(--color-accent);
}

.ledger-row .row-photo {
  grid-column: 2 / -1;
  margin: var(--space-xs) 0 0;
}

.row-photo a {
  display: inline-block;
}

.row-photo img {
  display: block;
  width: min(100%, 22rem);
  height: auto;
  border: var(--rule-hair) solid var(--color-rule);
  background: var(--color-surface);
}

.ledger-section {
  padding-block: var(--space-2xl) var(--space-3xl);
  border-top: var(--rule-hair) solid var(--color-rule-strong);
}

.patent-section {
  padding-bottom: var(--space-4xl);
}

.compact-section {
  padding-block: var(--space-xl) var(--space-2xl);
}

.section-lead {
  display: grid;
  gap: var(--space-xs);
  margin-bottom: var(--space-lg);
  text-align: left;
}

.section-lead h2,
.contact-section h2 {
  font-size: var(--text-xl);
  line-height: 1.15;
}

.section-lead .section-links a {
  color: var(--color-accent);
}

.section-lead p {
  max-width: var(--measure);
  margin: 0;
  color: var(--color-muted);
  font-size: var(--text-sm);
}

.ledger,
.plain-ledger {
  margin: 0;
  padding: 0;
  border-top: var(--rule-hair) solid var(--color-rule);
  list-style: none;
}

.ledger-row {
  display: grid;
  grid-template-columns: 7rem minmax(0, 1fr);
  grid-template-areas:
    "date title"
    ". description"
    ". action";
  gap: var(--space-xs) var(--space-md);
  align-items: baseline;
  padding-block: var(--space-md);
  border-bottom: var(--rule-hair) solid var(--color-rule);
  font-variant-numeric: tabular-nums;
}

.ledger-row time,
.ledger-row > span:first-child {
  grid-area: date;
  min-width: 0;
  color: var(--color-muted);
  font-size: var(--text-sm);
  font-variant-numeric: tabular-nums;
  line-height: 1.45;
  overflow-wrap: anywhere;
}

.ledger-row strong {
  grid-area: title;
  min-width: 0;
  font-weight: 700;
  line-height: 1.45;
  overflow-wrap: anywhere;
}

.ledger-row > span:nth-child(3) {
  grid-area: description;
  min-width: 0;
  color: var(--color-muted);
  font-size: var(--text-sm);
  line-height: 1.5;
  overflow-wrap: break-word;
  word-break: keep-all;
}

.ledger-row a,
.ledger-row > span:last-child[aria-hidden="true"] {
  grid-area: action;
  justify-self: start;
  font-size: var(--text-sm);
}

.ledger-row > span:last-child[aria-hidden="true"] {
  display: none;
}

.patent-ledger .ledger-row {
  font-size: var(--text-sm);
}

.patent-id {
  overflow-wrap: anywhere;
}

.pending-row {
  color: var(--color-muted);
}

.plain-ledger li {
  display: grid;
  gap: var(--space-xs);
  padding-block: var(--space-lg);
  border-bottom: var(--rule-hair) solid var(--color-rule);
}

.plain-ledger span {
  color: var(--color-muted);
}

/* Current research: a short statement, then the questions behind it. */
.now-body {
  display: grid;
  gap: var(--space-lg);
}

.now-lead {
  max-width: var(--measure);
  margin: 0;
  font-size: var(--text-lg);
  line-height: 1.7;
}

.now-list {
  margin: 0;
  padding: 0;
  border-top: var(--rule-hair) solid var(--color-rule);
  list-style: none;
}

.now-list li {
  display: grid;
  gap: var(--space-2xs);
  padding-block: var(--space-md);
  border-bottom: var(--rule-hair) solid var(--color-rule);
}

.now-list strong {
  min-width: 0;
  font-weight: 700;
  line-height: 1.45;
  overflow-wrap: anywhere;
}

.now-list span {
  min-width: 0;
  color: var(--color-muted);
  font-size: var(--text-sm);
  line-height: 1.6;
}

@media (min-width: 60rem) {
  .now-list li {
    grid-template-columns: 18rem minmax(0, 1fr);
    gap: var(--space-lg);
    padding-block: var(--space-lg);
  }
}

.contact-section {
  display: grid;
  gap: var(--space-lg);
  padding-block: var(--space-3xl) var(--space-4xl);
  border-top: var(--rule-hair) solid var(--color-rule-strong);
}

.foot-dense {
  padding-top: var(--space-lg);
  padding-bottom: max(var(--space-2xl), env(safe-area-inset-bottom));
  border-top: var(--rule-hair) solid var(--color-rule-strong);
  color: var(--color-muted);
  font-family: var(--font-outlier);
  font-size: var(--text-xs);
  line-height: 1.7;
}

.foot-dense p {
  max-width: var(--measure);
  margin: 0;
}

@media (min-width: 40rem) {
  .nav-mast {
    padding-top: var(--space-2xl);
  }

  .mast-name {
    font-size: 3.5rem;
  }

  .intro h2 {
    font-size: 2.75rem;
  }

  .section-lead h2,
  .contact-section h2 {
    font-size: var(--text-2xl);
  }

  .plain-ledger li {
    grid-template-columns: minmax(12rem, 0.8fr) minmax(0, 1.2fr);
  }
}

@media (min-width: 60rem) {
  .ledger-row {
    grid-template-columns: 10rem minmax(0, 1fr) max-content;
    grid-template-areas:
      "date title action"
      ". description action";
    gap: var(--space-xs) var(--space-lg);
    padding-block: var(--space-lg);
  }

  .ledger-row a {
    align-self: center;
    justify-self: start;
  }

  .patent-ledger .ledger-row {
    grid-template-columns: 11rem minmax(0, 1fr) max-content;
  }
}

/* Patents: one row per invention, grants by country open underneath. */
.patent-tools {
  display: flex;
  justify-content: flex-end;
  margin-bottom: var(--space-sm);
}

.patent-toggle {
  min-height: 2.25rem;
  padding: 0 var(--space-md);
  border: var(--rule-hair) solid var(--color-rule);
  border-radius: 999px;
  background: transparent;
  color: var(--color-accent);
  font: inherit;
  font-size: var(--text-sm);
  font-weight: 600;
  cursor: pointer;
}

.patent-families {
  margin: 0;
  padding: 0;
  list-style: none;
  border-top: var(--rule-hair) solid var(--color-rule);
}

.patent-family {
  border-bottom: var(--rule-hair) solid var(--color-rule);
}

.patent-family summary {
  display: grid;
  grid-template-columns: 7rem minmax(0, 1fr);
  grid-template-areas:
    "date title"
    ". meta"
    ". count";
  gap: var(--space-xs) var(--space-md);
  align-items: baseline;
  padding-block: var(--space-md);
  cursor: pointer;
  list-style: none;
}

.patent-family summary::-webkit-details-marker {
  display: none;
}

.pf-date {
  grid-area: date;
  color: var(--color-muted);
  font-size: var(--text-sm);
  font-variant-numeric: tabular-nums;
}

.pf-title {
  grid-area: title;
  min-width: 0;
  font-weight: 700;
  line-height: 1.45;
  word-break: keep-all;
}

.pf-meta {
  grid-area: meta;
  min-width: 0;
  color: var(--color-muted);
  font-size: var(--text-sm);
  line-height: 1.5;
  overflow-wrap: anywhere;
}

.pf-count {
  grid-area: count;
  justify-self: start;
  color: var(--color-accent);
  font-size: var(--text-sm);
  font-weight: 600;
  white-space: nowrap;
}

.pf-count::after {
  content: " ▾";
}

.patent-family details[open] .pf-count::after {
  content: " ▴";
}

.patent-family summary:hover .pf-title,
.patent-family summary:focus-visible .pf-title {
  color: var(--color-accent);
}

.pf-body {
  padding: 0 0 var(--space-md) calc(7rem + var(--space-md));
}

.pf-body p {
  max-width: var(--measure);
  margin: 0 0 var(--space-sm);
  color: var(--color-muted);
  font-size: var(--text-sm);
  line-height: 1.55;
  word-break: keep-all;
}

.pf-regs {
  display: grid;
  gap: var(--space-xs);
  margin: 0;
  padding: 0;
  list-style: none;
}

.pf-regs li {
  display: grid;
  grid-template-columns: 2.5rem minmax(0, 1fr) max-content;
  gap: var(--space-sm);
  align-items: baseline;
  font-size: var(--text-sm);
  font-variant-numeric: tabular-nums;
}

.pf-cc,
.pf-regs time,
.pf-zl {
  color: var(--color-muted);
}

.pf-cc {
  font-weight: 600;
}

.pf-regs a {
  font-weight: 600;
  overflow-wrap: anywhere;
}

.pf-zl {
  margin-left: var(--space-xs);
  font-size: 0.85em;
}

.patent-pending {
  margin-top: var(--space-lg);
}

.patent-pending > summary {
  color: var(--color-accent);
  font-size: var(--text-sm);
  font-weight: 600;
  cursor: pointer;
}

.patent-pending[open] > summary {
  margin-bottom: var(--space-sm);
}

@media (max-width: 30rem) {
  .pf-body {
    padding-left: 0;
  }

  .pf-regs li {
    grid-template-columns: 2.5rem minmax(0, 1fr);
    gap: 0 var(--space-sm);
  }

  .pf-regs time {
    grid-column: 2;
  }
}

@media (min-width: 60rem) {
  .patent-family summary {
    grid-template-columns: 11rem minmax(0, 1fr) max-content;
    grid-template-areas:
      "date title count"
      ". meta count";
    gap: var(--space-xs) var(--space-lg);
    padding-block: var(--space-lg);
  }

  .pf-count {
    align-self: center;
  }

  .pf-body {
    padding-left: calc(11rem + var(--space-lg));
  }
}

@media print {
  .patent-tools {
    display: none;
  }
}

@media (pointer: coarse) {
  .mast-nav a,
  .intro-links a,
  .contact-links a,
  .ledger-row a {
    display: inline-flex;
    min-height: 2.75rem;
    align-items: center;
  }
}

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

@media print {
  .mast-nav,
  .intro-links,
  .ledger-row a,
  .contact-section {
    display: none;
  }

  html,
  body {
    background: #ffffff;
  }

  body {
    font-size: 10pt;
  }

  .ledger-section,
  .intro {
    padding-block: var(--space-lg);
  }
}


/* The two introduction slides, adapted for the web with the five original photos. */
.profile-panel {
  --profile-muted: #b5c4d1;
  --profile-accent: #99c8ff;
  margin-block: 2rem;
  padding: clamp(1.25rem, 3.2vw, 2.5rem);
  background: #101820;
  color: #f5f7fa;
}
.profile-heading { display: flex; align-items: flex-start; justify-content: space-between; gap: 1.5rem; padding-bottom: 1.5rem; margin-bottom: 1.5rem; border-bottom: 1px solid #354757; }
.profile-heading h2 { margin: 0; font-size: clamp(1.75rem, 3.2vw, 2.65rem); line-height: 1.2; font-weight: 700; }
.profile-heading h2 span { display: inline-block; margin-left: .6rem; color: var(--profile-muted); font-size: .6em; font-weight: 400; }
.profile-role { margin: .8rem 0 0; color: var(--profile-accent); font-size: 1rem; }
.profile-org { flex-shrink: 0; margin: .3rem 0 0; text-align: right; font-size: .9rem; }
.profile-org strong, .profile-org span { display: block; }
.profile-org span { margin-top: .45rem; color: var(--profile-muted); font-size: .8rem; }
.profile-grid { display: grid; grid-template-columns: 1fr 1fr; align-items: start; gap: clamp(1.5rem, 3vw, 2.5rem); }
.profile-grid > * { min-width: 0; }
.profile-panel figure { margin: 0; }
.profile-panel img { display: block; width: 100%; height: auto; object-fit: contain; }
.profile-panel figcaption { margin-top: .55rem; color: var(--profile-muted); font-size: .8rem; line-height: 1.5; }
.product-photos { display: grid; grid-template-columns: repeat(3,minmax(0,1fr)); gap: .65rem; margin-top: 1.1rem; }
.product-photos img { height: clamp(4rem, 6.5vw, 6rem); background: #182430; }
.product-photos figcaption { text-align: center; font-size: .75rem; }
.career-summary { display: grid; gap: 1.25rem; padding: 0; margin: 0; list-style: none; }
.career-summary li { border-left: 2px solid #354757; padding-left: 1rem; }
.career-summary li:last-child { border-color: var(--profile-accent); }
.career-summary h3 { margin: 0 0 .45rem; font-size: clamp(1.05rem,1.7vw,1.3rem); font-weight: 700; line-height: 1.3; }
.career-summary li:last-child h3 { color: var(--profile-accent); }
.career-summary li > div { display: grid; grid-template-columns: 5.9rem 1fr; gap: .65rem; }
.career-date { color: var(--profile-muted); font-size: .75rem; padding-top: .1rem; }
.career-summary p { margin: 0; font-size: .9rem; line-height: 1.55; color: var(--profile-muted); }
.profile-links { display: flex; flex-wrap: wrap; gap: .5rem 1.5rem; margin-top: 1.5rem; border-top: 1px solid #354757; padding-top: .8rem; font-size: .85rem; }
.profile-links a { display: inline-flex; min-height: 44px; align-items: center; }
.profile-panel a { color: var(--profile-muted); }
.profile-panel a:hover { color: var(--profile-accent); }
.summit-photo figcaption strong, .summit-photo figcaption span { display: block; }
.summit-photo figcaption strong { margin-top: .9rem; color: #f5f7fa; font-size: 1rem; }
.summit-photo figcaption span { margin-top: .4rem; }
.research-summary { display: grid; gap: 1rem; }
.research-summary section + section { border-top: 1px solid #354757; padding-top: 1rem; }
.research-summary h3 { margin: 0 0 .45rem; font-size: 1.15rem; line-height: 1.3; }
.research-summary section:first-child h3, .research-summary .product-awards h3 { color: var(--profile-accent); }
.research-summary p { margin: 0; color: var(--profile-muted); font-size: .9rem; line-height: 1.6; }
.research-summary .product-awards h3 { font-size: .9rem; }
.photo-gallery { display: grid; grid-template-columns: repeat(3, minmax(0, 1fr)); gap: .75rem; margin: 0; padding: 0; list-style: none; }
.photo-gallery a { display: block; background: #182430; }
.photo-gallery img { aspect-ratio: 3 / 2; object-fit: cover; transition: opacity 150ms ease; }
.photo-gallery figcaption { padding: .25rem .1rem 0; }
.photo-gallery figcaption strong, .photo-gallery figcaption span { display: block; overflow-wrap: anywhere; }
.photo-gallery figcaption strong { color: #f5f7fa; font-weight: 700; }
.photo-gallery figcaption span { margin-top: .2rem; }
.photo-gallery .fit-contain img { object-fit: contain; background: #182430; }
.photo-gallery a:hover img, .photo-gallery a:focus-visible img { opacity: .85; }
.lightbox { width: min(96vw, 80rem); max-width: none; max-height: 96vh; padding: 0; border: 0; background: #101820; }
.lightbox::backdrop { background: rgba(6, 10, 14, .88); }
.lightbox img { display: block; width: 100%; height: auto; max-height: 92vh; object-fit: contain; }
.lightbox-close { position: absolute; top: .5rem; right: .5rem; width: 2.75rem; height: 2.75rem; border: 0; border-radius: 999px; background: rgba(16, 24, 32, .75); color: #f5f7fa; font-size: 1.5rem; line-height: 1; cursor: pointer; }
.award-strip { display: grid; grid-template-columns: repeat(3, minmax(0, 1fr)); gap: 1rem 1.5rem; margin: 1.5rem 0 0; padding: 1rem 0 0; border-top: 1px solid #354757; list-style: none; }
.award-photos { display: grid; grid-template-columns: repeat(3, minmax(0, 1fr)); gap: .75rem; margin: 1rem 0 0; padding: 0; list-style: none; }
.award-photos a { display: block; background: #182430; }
.award-photos img { aspect-ratio: 3 / 2; object-fit: cover; }
.award-strip li { min-width: 0; font-size: .85rem; line-height: 1.5; }
.award-strip span { display: block; color: var(--profile-muted); font-size: .75rem; }
.award-strip strong { font-weight: 600; color: #f5f7fa; }
.award-strip li:last-child strong { color: var(--profile-accent); }
@media (max-width: 760px) {
  .award-strip { grid-template-columns: 1fr; gap: .75rem; }
  .award-photos { grid-template-columns: repeat(2, minmax(0, 1fr)); gap: .5rem; }
  .photo-gallery { grid-template-columns: repeat(2, minmax(0, 1fr)); gap: .5rem; }
  .profile-heading { flex-direction: column; gap: 1rem; }
  .profile-org { text-align: left; }
  .profile-grid { grid-template-columns: 1fr; }
  .product-photos img { height: clamp(3.5rem,16vw,7rem); }
  .career-summary { gap: 1.4rem; }
  .career-summary li > div { grid-template-columns: 1fr; gap: .25rem; }
  .profile-panel { margin-inline: calc(-1 * var(--page-gutter)); padding-inline: var(--page-gutter); }
}
@media (prefers-reduced-motion: reduce) { html { scroll-behavior: auto; } }

.section-return {
  position: fixed;
  right: 18px;
  bottom: 18px;
  z-index: 20;
  display: flex;
  align-items: center;
  justify-content: center;
  min-height: 44px;
  padding: 9px 16px;
  border: 1px solid var(--color-rule-strong);
  border-radius: 7px;
  background: var(--color-paper);
  color: var(--color-ink);
  font-size: 12px;
  text-decoration: none;
  box-shadow: 0 3px 12px #0001;
}
@media print { .section-return { display: none; } }

.material-list { display: grid; grid-template-columns: repeat(2, minmax(0, 1fr)); gap: 1rem; margin: 0; padding: 0; list-style: none; }
.material-list li { min-width: 0; padding: 1.25rem; border: 1px solid var(--color-rule); background: var(--color-surface); }
.material-list h3 { margin: 0 0 .5rem; font-size: 1.05rem; line-height: 1.45; overflow-wrap: anywhere; }
.material-list p { margin: 0; color: var(--color-muted); font-size: .85rem; }
.material-links { display: flex; flex-wrap: wrap; gap: .25rem 1.25rem; margin-top: .75rem; }
.material-links a, .materials-return, .portfolio-home { display: inline-flex; align-items: center; min-height: 44px; font-size: .85rem; }
.materials-return { margin-top: 1rem; }
@media (max-width: 760px) { .material-list { grid-template-columns: 1fr; } }

/* 휴대폰·터치 사용성: 좁은 화면(820px 이하)이나 터치 기기에서 단독 링크와 펼치기 버튼을 44px 이상으로 둔다. 넓은 PC 화면은 그대로. */
@media (max-width: 820px), (pointer: coarse) {
  .mast-nav a,
  .ledger-row a,
  .interview-photo figcaption a {
    display: inline-flex;
    min-width: 2.75rem;
    min-height: 2.75rem;
    align-items: center;
  }

  .patent-toggle {
    min-height: 2.75rem;
  }
}