:root {
  --ink: #0B1020;
  --paper: #F7F8FB;
  --deep: #1E3AFF;
  --coral: #FF6B4A;
  --gray-700: #374151;
  --gray-500: #6B7280;
  --gray-300: #D1D5DB;
  --gray-200: #E5E7EB;
  --gray-100: #F3F4F6;
  --white: #FFFFFF;
  --max: 1160px;
  --section-pad-y: clamp(64px, 10vw, 120px);
}

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

html { scroll-behavior: smooth; }
body {
  background: var(--paper);
  color: var(--ink);
  font-family: 'Inter', 'Pretendard', -apple-system, 'Helvetica Neue', Arial, sans-serif;
  line-height: 1.6;
  -webkit-font-smoothing: antialiased;
  font-feature-settings: 'kern', 'liga';
  text-rendering: optimizeLegibility;
}

img, svg { display: block; max-width: 100%; }
a { color: inherit; text-decoration: none; transition: color .2s; }
a:hover { color: var(--deep); }
ol, ul { list-style: none; }

.visually-hidden {
  position: absolute; width: 1px; height: 1px; padding: 0; margin: -1px;
  overflow: hidden; clip: rect(0,0,0,0); white-space: nowrap; border: 0;
}

.container {
  max-width: var(--max);
  margin: 0 auto;
  padding: 0 clamp(20px, 5vw, 32px);
}

/* shared section header */
.section-head { margin-bottom: clamp(40px, 6vw, 64px); }
.section-head h2 {
  font-size: clamp(22px, 3vw, 32px);
  font-weight: 700;
  letter-spacing: -0.02em;
  margin-bottom: 12px;
}
.section-head p {
  color: var(--gray-500);
  font-size: clamp(14px, 1.4vw, 15px);
  max-width: 640px;
}

/* ============ HERO ============ */
.hero {
  position: relative;
  min-height: clamp(560px, 88vh, 880px);
  display: flex;
  align-items: center;
  justify-content: center;
  overflow: hidden;
  padding: 80px 0;
}
.hero__inner {
  position: relative;
  z-index: 1;
  text-align: center;
}
.hero__logo {
  width: clamp(220px, 28vw, 360px);
  height: auto;
  margin: 0 auto clamp(28px, 4vw, 44px);
}
.hero__headline {
  font-size: clamp(22px, 4.5vw, 44px);
  font-weight: 700;
  letter-spacing: -0.03em;
  line-height: 1.4;
  max-width: 880px;
  margin: 0 auto;
  word-break: keep-all;
}
.hero__sublabel {
  margin-top: clamp(24px, 4vw, 40px);
  display: flex;
  flex-direction: column;
  gap: 10px;
  font-size: 13px;
  color: var(--gray-500);
}
.hero__verbs {
  letter-spacing: 0.04em;
  font-size: clamp(13px, 1.4vw, 14px);
}
.hero__en {
  letter-spacing: 0.32em;
  font-size: 11px;
  font-weight: 600;
  color: var(--ink);
}
.hero__arc {
  position: absolute;
  width: clamp(280px, 50vw, 580px);
  height: auto;
  right: clamp(-260px, -18vw, -120px);
  bottom: 8%;
  opacity: 0.05;
  pointer-events: none;
  z-index: 0;
  transform-origin: center center;
  animation: arc-fade-in 1.4s 0.4s ease-out both, arc-spin 90s 2s linear infinite;
}
.hero__arc path {
  stroke-dasharray: 4 8;
  animation: arc-flow 6s linear infinite;
}
@media (max-width: 600px) {
  .hero__arc {
    right: -36%;
    bottom: -4%;
    animation: arc-fade-in-mobile 1.4s 0.4s ease-out both, arc-spin 90s 2s linear infinite;
  }
}

/* hero entrance + ambient motion */
@keyframes hero-fade-up {
  from { opacity: 0; transform: translateY(20px); }
  to { opacity: 1; transform: translateY(0); }
}
@keyframes hero-fade-scale {
  from { opacity: 0; transform: scale(0.94); }
  to { opacity: 1; transform: scale(1); }
}
@keyframes arc-fade-in {
  from { opacity: 0; }
  to { opacity: 0.05; }
}
@keyframes arc-fade-in-mobile {
  from { opacity: 0; }
  to { opacity: 0.07; }
}
@keyframes arc-spin {
  to { transform: rotate(360deg); }
}
@keyframes arc-flow {
  to { stroke-dashoffset: -36; }
}

.hero__logo {
  animation: hero-fade-scale 0.8s 0.15s cubic-bezier(.22,.61,.36,1) both;
}
.hero__headline .line {
  display: block;
  animation: hero-fade-up 0.7s cubic-bezier(.22,.61,.36,1) both;
}
.hero__headline .line:nth-child(1) { animation-delay: 0.4s; }
.hero__headline .line:nth-child(2) { animation-delay: 0.6s; }
.hero__headline .line:nth-child(3) { animation-delay: 0.8s; }
.hero__sublabel {
  animation: hero-fade-up 0.7s 1.15s cubic-bezier(.22,.61,.36,1) both;
}

/* ============ CONCEPT ============ */
.concept { padding: var(--section-pad-y) 0; }
.concept-grid {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: 16px;
  perspective: 1400px;
}
.concept-card {
  background: transparent;
  border: none;
  padding: 0;
  min-height: 280px;
  position: relative;
}
.concept-card__inner {
  position: relative;
  width: 100%;
  min-height: 280px;
  transform-style: preserve-3d;
  animation: card-auto-flip 18s ease-in-out infinite;
}
.concept-card:nth-child(1) .concept-card__inner { animation-delay: 0s; }
.concept-card:nth-child(2) .concept-card__inner { animation-delay: 6s; }
.concept-card:nth-child(3) .concept-card__inner { animation-delay: 12s; }
.concept-card:hover .concept-card__inner,
.concept-card:focus-within .concept-card__inner {
  animation-play-state: paused;
}
@keyframes card-auto-flip {
  0%, 11% { transform: rotateY(0); }
  22%, 33% { transform: rotateY(180deg); }
  44%, 100% { transform: rotateY(0); }
}
.concept-card__face {
  position: absolute;
  inset: 0;
  background: var(--white);
  border: 1px solid var(--gray-200);
  padding: clamp(32px, 4vw, 56px) clamp(24px, 3vw, 36px);
  display: flex;
  flex-direction: column;
  justify-content: center;
  -webkit-backface-visibility: hidden;
  backface-visibility: hidden;
}
.concept-card__face .concept-card__index {
  position: absolute;
  top: clamp(28px, 3.5vw, 40px);
  left: clamp(24px, 3vw, 36px);
  margin-bottom: 0;
}
.concept-card__face--front {
  align-items: center;
  text-align: center;
}
.concept-card__face--front .concept-card__verb {
  font-size: clamp(36px, 5vw, 52px);
  margin-bottom: 0;
}
.concept-card__face--back {
  align-items: stretch;
  transform: rotateY(180deg);
  background: var(--deep);
  color: var(--white);
  border-color: transparent;
}
.concept-card__face--back .concept-card__index { color: rgba(255,255,255,0.7); }
.concept-card__face--back .concept-card__desc {
  color: rgba(255,255,255,0.92);
  font-size: clamp(15px, 1.7vw, 17px);
  font-weight: 500;
  line-height: 1.7;
  margin-top: 0;
}
@media (prefers-reduced-motion: reduce) {
  .concept-card__inner { animation: none; }
  .concept-card:hover .concept-card__inner,
  .concept-card:focus-within .concept-card__inner { animation-play-state: running; }
}
.concept-card__index {
  font-size: 11px;
  letter-spacing: 0.18em;
  font-weight: 600;
  color: var(--gray-500);
  margin-bottom: clamp(24px, 3vw, 36px);
  font-feature-settings: 'tnum';
  text-transform: uppercase;
}
.concept-card__verb {
  font-size: clamp(28px, 3.5vw, 38px);
  font-weight: 700;
  letter-spacing: -0.02em;
  margin-bottom: 20px;
  line-height: 1;
}
.concept-card__desc {
  font-size: clamp(14px, 1.4vw, 15px);
  color: var(--gray-500);
  margin-top: auto;
  word-break: keep-all;
}

@media (max-width: 768px) {
  .concept-grid { grid-template-columns: 1fr; gap: 12px; }
  .concept-card { min-height: 220px; }
  .concept-card__inner { min-height: 220px; }
  .concept-card__face { padding: 32px 28px; }
}

/* ============ TIMELINE ============ */
.timeline {
  background: var(--white);
  padding: var(--section-pad-y) 0;
}
.timeline .section-head p {
  max-width: none;
  white-space: nowrap;
}
@media (max-width: 900px) {
  .timeline .section-head p { white-space: normal; }
}
.timeline-grid {
  display: flex;
  flex-direction: column;
  gap: clamp(20px, 3vw, 28px);
}
.timeline-row {
  display: grid;
  grid-template-columns: 96px 1fr;
  gap: 24px;
  align-items: start;
}
.lane-label {
  padding-top: 4px;
  font-size: 12px;
  font-weight: 600;
  color: var(--gray-500);
  letter-spacing: 0.04em;
}
.lane-bars {
  display: grid;
  grid-template-columns: repeat(16, minmax(0, 1fr));
  grid-auto-rows: 28px;
  grid-auto-flow: row dense;
  gap: 6px;
}
.bar {
  grid-column: var(--cs) / var(--ce);
  background: var(--ink);
  color: var(--white);
  padding: 0 12px;
  display: flex;
  align-items: center;
  font-size: 11px;
  font-weight: 500;
  white-space: nowrap;
  overflow: hidden;
  text-overflow: ellipsis;
  transform: scaleX(0.001);
  transform-origin: left center;
  transition: transform 0.7s cubic-bezier(.4,0,.2,1);
  transition-delay: var(--delay, 0s);
}
.bar--current { background: var(--deep); }
.timeline.is-visible .bar { transform: scaleX(1); }

.timeline-axis {
  display: grid;
  grid-template-columns: 96px 1fr;
  gap: 24px;
  margin-top: 16px;
  padding-top: 16px;
  border-top: 1px solid var(--gray-200);
}
.timeline-years {
  display: grid;
  grid-template-columns: repeat(16, minmax(0, 1fr));
  gap: 6px;
  font-feature-settings: 'tnum';
  font-size: 10px;
  color: var(--gray-500);
}
.timeline-years span { text-align: center; }
.timeline-years span.current { color: var(--deep); font-weight: 600; }

/* tablet narrows lane label */
@media (max-width: 1024px) {
  .timeline-row, .timeline-axis { grid-template-columns: 80px 1fr; gap: 16px; }
  .lane-bars, .timeline-years { gap: 4px; }
  .bar { font-size: 10px; padding: 0 8px; }
}

/* mobile: collapse to vertical card list per lane */
@media (max-width: 720px) {
  .timeline-row {
    grid-template-columns: 1fr;
    gap: 12px;
    padding-top: 8px;
  }
  .lane-label {
    font-size: 11px;
    color: var(--ink);
    letter-spacing: 0.18em;
    text-transform: uppercase;
    padding: 0 0 8px;
    border-bottom: 2px solid var(--ink);
  }
  .lane-bars {
    grid-template-columns: 1fr;
    grid-auto-rows: auto;
    gap: 8px;
  }
  .bar {
    grid-column: 1 / -1 !important;
    padding: 12px 14px;
    font-size: 13px;
    height: auto;
    white-space: normal;
    transform: none;
    opacity: 0;
    transition: opacity .5s ease, transform .5s ease;
    transform: translateY(8px);
  }
  .timeline.is-visible .bar { opacity: 1; transform: translateY(0); }
  .bar::before {
    content: attr(data-years);
    font-size: 10px;
    color: rgba(255,255,255,0.65);
    margin-right: 12px;
    letter-spacing: 0.06em;
    font-feature-settings: 'tnum';
    flex-shrink: 0;
    font-weight: 600;
  }
  .timeline-axis { display: none; }
}

@media (prefers-reduced-motion: reduce) {
  .bar { transform: none !important; opacity: 1 !important; transition: none !important; }
  .hero__logo, .hero__headline .line, .hero__sublabel { animation: none !important; opacity: 1 !important; transform: none !important; }
  .hero__arc { animation: none !important; opacity: 0.05 !important; transform: none !important; }
  .hero__arc path { animation: none !important; stroke-dasharray: none !important; }
  html { scroll-behavior: auto; }
}

/* ============ ORG ============ */
.org {
  background: var(--white);
  padding: var(--section-pad-y) 0;
}

.org-tree, .org-tree ul {
  list-style: none;
  margin: 0;
  padding: 0;
}
.org-tree { display: flex; justify-content: center; }
.org-tree li {
  position: relative;
  text-align: center;
}

.org-card {
  display: inline-flex;
  flex-direction: column;
  gap: 6px;
  padding: 18px 28px;
  background: var(--white);
  border: 1px solid var(--gray-200);
  min-width: 168px;
  text-align: center;
}
.org-card--ceo {
  background: var(--ink);
  color: var(--white);
  border-color: transparent;
  padding: 14px 36px;
  min-width: 220px;
}
.org-card--dept {
  padding: 0;
  min-width: 200px;
  text-align: left;
  align-items: stretch;
  gap: 0;
  overflow: hidden;
}
.org-card--dept .org-name {
  display: block;
  background: var(--ink);
  color: var(--white);
  padding: 12px 16px;
  text-align: center;
  font-weight: 600;
  letter-spacing: 0.02em;
}
.org-card--dept .org-meta {
  padding: 12px 20px 14px;
  color: var(--gray-500);
  text-align: center;
}
.org-card--team {
  padding: 0;
  min-width: 184px;
  text-align: left;
  align-items: stretch;
  gap: 0;
  overflow: hidden;
}
.org-card--team .org-name {
  display: block;
  background: var(--ink);
  color: var(--white);
  padding: 12px 16px;
  text-align: center;
  font-weight: 600;
  letter-spacing: 0.02em;
}
.org-card--team .org-tags {
  padding: 14px 20px 16px;
  margin-top: 0;
  gap: 6px;
}
.org-name {
  font-size: 15px;
  font-weight: 700;
  letter-spacing: -0.01em;
}
.org-card--ceo .org-name { font-size: 18px; }
.org-meta {
  font-size: 11px;
  font-weight: 500;
  color: var(--gray-500);
  letter-spacing: 0.04em;
}
.org-card--ceo .org-meta { color: rgba(255,255,255,0.7); }

.org-tags {
  display: flex;
  flex-direction: column;
  gap: 4px;
  margin-top: 8px;
}
.org-tags span {
  font-size: 11px;
  color: var(--gray-500);
  letter-spacing: 0.02em;
}

.org-tree li > ul {
  display: flex;
  justify-content: center;
  padding-top: 24px;
  margin-top: 8px;
  position: relative;
}
.org-tree li > ul::before {
  content: '';
  position: absolute;
  top: -8px;
  left: 50%;
  width: 1px;
  height: 32px;
  background: var(--gray-300);
}
.org-tree li > ul > li {
  padding: 18px 12px 0;
  position: relative;
}
.org-tree li > ul > li::before {
  content: '';
  position: absolute;
  top: 0;
  left: 50%;
  width: 1px;
  height: 18px;
  background: var(--gray-300);
}
.org-tree li > ul > li::after {
  content: '';
  position: absolute;
  top: 0;
  height: 1px;
  background: var(--gray-300);
  left: 0;
  right: 0;
}
.org-tree li > ul > li:only-child::after { display: none; }
.org-tree li > ul > li:first-child:not(:only-child)::after { left: 50%; }
.org-tree li > ul > li:last-child:not(:only-child)::after { right: 50%; }

@media (max-width: 720px) {
  .org-tree { justify-content: flex-start; }
  .org-tree li { text-align: left; }
  .org-tree li > ul {
    flex-direction: column;
    align-items: stretch;
    padding: 10px 0 4px 18px;
    margin: 4px 0 0 16px;
    border-left: 2px solid var(--gray-200);
    gap: 8px;
  }
  .org-tree li > ul::before,
  .org-tree li > ul > li::before,
  .org-tree li > ul > li::after { display: none; }
  .org-tree li > ul > li { padding: 0; }
  .org-card {
    width: 100%;
    min-width: 0;
    text-align: left;
  }
  .org-card--ceo, .org-card--dept { padding: 16px 20px; }
  .org-card--ceo { min-width: 0; }
  .org-card--team .org-tags {
    flex-direction: row;
    flex-wrap: wrap;
    gap: 6px 12px;
  }
}

/* ============ FOOTER ============ */
footer {
  border-top: 1px solid var(--gray-200);
  padding: 32px 0;
  font-size: 12px;
  color: var(--gray-500);
  line-height: 1.75;
}
.footer-grid {
  display: flex;
  align-items: flex-start;
  gap: 18px;
}
.footer-logo {
  flex-shrink: 0;
  height: 24px;
  width: auto;
  margin-top: 2px;
  opacity: 0.75;
}
.footer-info {
  display: flex;
  flex-direction: column;
  gap: 4px;
  min-width: 0;
}
.footer-line {
  word-break: keep-all;
}
.footer-line--primary {
  color: var(--ink);
  font-weight: 500;
  margin-bottom: 4px;
}
.footer-sep {
  color: var(--gray-300);
  margin: 0 6px;
  font-weight: 300;
}
.footer-line a { color: inherit; }
.footer-line a:hover { color: var(--deep); }

@media (max-width: 600px) {
  .footer-grid { flex-direction: column; gap: 14px; }
  footer { font-size: 11px; }
  .footer-sep { margin: 0 4px; }
}