/* ============================================================
   ARRC 10주년 기념 심포지엄
   Theme lock : light only (색상 토큰은 :root 한 곳에서만 관리)
   Radius rule: 컨테이너 14px / 인터랙티브 요소 10px / 그 외 없음
   ============================================================ */

:root {
  color-scheme: light;

  /* ARRC 로고의 주황을 액센트로 쓰는 라이트 테마.
     페이지 전체가 이 한 벌로 통일되므로 여기만 고치면 됩니다. */
  --bg:          #F7F6F3;
  --bg-alt:      #EFEDE7;
  --surface:     #FFFFFF;
  --surface-hi:  #F1EFEA;

  --line:        rgba(27, 29, 33, .11);
  --line-hi:     rgba(27, 29, 33, .24);

  --fg:          #1B1D21;
  --fg-2:        #494E56;
  --fg-3:        #63686F;

  --accent:      #C6410F;
  --accent-hi:   #A93509;
  --accent-soft: rgba(198, 65, 15, .08);
  --accent-ink:  #FFFFFF;

  --r-box:  14px;
  --r-ui:   10px;

  --wrap:   1200px;
  --nav-h:  68px;

  --pad-y:  clamp(6.5rem, 11vw, 10rem);

  --mono: ui-monospace, SFMono-Regular, "SF Mono", "Cascadia Mono", Menlo, Consolas, monospace;
  --sans: "Pretendard Variable", Pretendard, -apple-system, BlinkMacSystemFont,
          system-ui, "Segoe UI", "Malgun Gothic", sans-serif;

  --ease: cubic-bezier(.16, 1, .3, 1);
}

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

html {
  scroll-behavior: smooth;
  scroll-padding-top: calc(var(--nav-h) + 16px);
  -webkit-text-size-adjust: 100%;
}

body {
  margin: 0;
  background: var(--bg);
  color: var(--fg);
  font-family: var(--sans);
  font-size: 1rem;
  line-height: 1.7;
  letter-spacing: -.01em;
  -webkit-font-smoothing: antialiased;
  overflow-x: hidden;
}

h1, h2, h3 { margin: 0; line-height: 1.15; letter-spacing: -.03em; font-weight: 700; }
p  { margin: 0; }
ol, ul, dl, dd { margin: 0; padding: 0; }
li { list-style: none; }
img, iframe { max-width: 100%; display: block; }

a { color: inherit; text-decoration: none; }
a:focus-visible,
button:focus-visible,
[tabindex]:focus-visible {
  outline: 2px solid var(--accent);
  outline-offset: 3px;
  border-radius: 4px;
}

.wrap {
  width: 100%;
  max-width: var(--wrap);
  margin-inline: auto;
  padding-inline: clamp(1.25rem, 4vw, 2.5rem);
}

.skip-link {
  position: absolute;
  left: 1rem;
  top: -100px;
  z-index: 100;
  padding: .7rem 1.1rem;
  background: var(--accent);
  color: var(--accent-ink);
  font-weight: 700;
  border-radius: var(--r-ui);
  transition: top .18s var(--ease);
}
.skip-link:focus { top: 1rem; }

/* ── Buttons ─────────────────────────────────────────────── */

.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: .5rem;
  white-space: nowrap;
  padding: .85rem 1.5rem;
  border: 1px solid transparent;
  border-radius: var(--r-ui);
  font: inherit;
  font-weight: 700;
  letter-spacing: -.01em;
  cursor: pointer;
  transition: background-color .2s var(--ease), border-color .2s var(--ease),
              color .2s var(--ease), transform .12s var(--ease);
}
.btn--primary { background: var(--accent); color: var(--accent-ink); }
.btn--primary:hover { background: var(--accent-hi); }

.btn--ghost { background: transparent; color: var(--fg); border-color: var(--line-hi); }
.btn--ghost:hover { border-color: var(--fg-2); background: rgba(27, 29, 33, .04); }

.btn--sm { padding: .6rem 1.05rem; font-size: .9rem; }
.btn--lg { padding: 1.05rem 2.25rem; font-size: 1.0625rem; }

.btn:active { transform: translateY(1px); }

.btn[aria-disabled="true"] {
  background: var(--surface-hi);
  color: var(--fg-3);
  border-color: var(--line);
  cursor: not-allowed;
  pointer-events: none;
}

/* ── 초안 안내 배너 (확정 후 제거) ───────────────────────── */

.draft {
  background: var(--accent-soft);
  border-bottom: 1px solid rgba(198, 65, 15, .3);
}
.draft__inner {
  display: flex;
  align-items: center;
  gap: .6rem;
  padding-block: .7rem;
}
.draft i { flex: none; color: var(--accent); font-size: 1.125rem; line-height: 1; }
.draft p { font-size: .875rem; color: var(--fg); }

/* ── Nav ─────────────────────────────────────────────────── */

.nav {
  position: sticky;
  top: 0;
  z-index: 50;
  height: var(--nav-h);
  background: rgba(247, 246, 243, .8);
  backdrop-filter: blur(14px);
  -webkit-backdrop-filter: blur(14px);
  border-bottom: 1px solid transparent;
  transition: border-color .25s var(--ease), background-color .25s var(--ease);
}
.nav.is-stuck {
  border-bottom-color: var(--line);
  background: rgba(247, 246, 243, .95);
}

.nav__inner {
  height: 100%;
  display: flex;
  align-items: center;
  gap: 1.5rem;
}

.brand { display: inline-flex; align-items: center; gap: .55rem; flex: none; }
.brand__logo { height: 40px; width: auto; }
.brand__name { font-size: 1.2rem; font-weight: 800; letter-spacing: .04em; }
/* 배지가 이름 기준선에 붙도록 이름과 배지만 baseline 정렬한다. */
.brand__name, .brand__badge { align-self: center; }
.brand__badge {
  font-size: .8rem;
  font-weight: 700;
  color: var(--accent);
  letter-spacing: 0;
}
.brand__badge sup { font-size: .62em; }

.nav__links {
  display: flex;
  align-items: center;
  gap: clamp(1rem, 2.2vw, 2rem);
  margin-inline-start: auto;
  font-size: .9375rem;
  color: var(--fg-2);
  white-space: nowrap;
}
.nav__links a { transition: color .18s var(--ease); }
.nav__links a:hover { color: var(--fg); }

.nav__actions { display: flex; align-items: center; gap: .6rem; flex: none; }

.lang {
  padding: .45rem .7rem;
  min-width: 46px;
  background: transparent;
  border: 1px solid var(--line-hi);
  border-radius: var(--r-ui);
  color: var(--fg-2);
  font: inherit;
  font-size: .8125rem;
  font-weight: 700;
  letter-spacing: .06em;
  cursor: pointer;
  transition: color .18s var(--ease), border-color .18s var(--ease);
}
.lang:hover { color: var(--fg); border-color: var(--fg-3); }

.burger {
  display: none;
  padding: .4rem;
  background: transparent;
  border: 0;
  color: var(--fg);
  font-size: 1.5rem;
  line-height: 1;
  cursor: pointer;
}

/* ── Hero ────────────────────────────────────────────────── */

.hero {
  position: relative;
  min-height: calc(100dvh - var(--nav-h));
  display: flex;
  align-items: center;
  padding-block: clamp(3rem, 7vw, 6rem);
  overflow: hidden;
}

/* 배경 사진. 종이 톤에 스며들도록 채도를 빼고 밝은 스크림을 얹는다. */
.hero__photo {
  position: absolute;
  inset: 0;
  width: 100%;
  height: 100%;
  object-fit: cover;
  object-position: center 38%;
  opacity: .4;
  filter: grayscale(.6) contrast(1.04);
  pointer-events: none;
}
.hero::before {
  content: "";
  position: absolute;
  inset: 0;
  z-index: 1;
  background:
    linear-gradient(100deg, var(--bg) 22%, rgba(247, 246, 243, .84) 48%, rgba(247, 246, 243, .5) 100%),
    linear-gradient(to bottom, rgba(247, 246, 243, .75) 0%, transparent 30%, var(--bg) 100%);
  pointer-events: none;
}

/* AR 공간 앵커를 연상시키는 원근 그리드. 장식이므로 aria-hidden. */
.hero__field {
  position: absolute;
  inset: -20% -10% 0;
  background-image:
    linear-gradient(to right,  var(--line) 1px, transparent 1px),
    linear-gradient(to bottom, var(--line) 1px, transparent 1px);
  background-size: 84px 84px;
  transform: perspective(900px) rotateX(58deg) translateY(12%);
  transform-origin: bottom center;
  -webkit-mask-image: radial-gradient(120% 80% at 50% 100%, #000 0%, transparent 72%);
          mask-image: radial-gradient(120% 80% at 50% 100%, #000 0%, transparent 72%);
  opacity: .8;
  z-index: 2;
  pointer-events: none;
}
.hero::after {
  content: "";
  position: absolute;
  z-index: 1;
  left: 50%;
  bottom: -38%;
  width: min(1100px, 120%);
  aspect-ratio: 1;
  transform: translateX(-50%);
  background: radial-gradient(circle, var(--accent-soft) 0%, transparent 62%);
  pointer-events: none;
}

.hero__inner {
  position: relative;
  z-index: 3;
  display: grid;
  grid-template-columns: minmax(0, 1.35fr) minmax(0, .65fr);
  align-items: center;
  gap: clamp(2rem, 5vw, 4rem);
}

.hero__title {
  font-size: clamp(2.35rem, 5.4vw, 4rem);
  line-height: 1.1;
  letter-spacing: -.04em;
}
.hero__sub {
  margin-top: 1.25rem;
  max-width: 46ch;
  color: var(--fg-2);
  font-size: clamp(1rem, 1.5vw, 1.125rem);
}

.hero__meta {
  margin-top: 3rem;
  display: flex;
  flex-wrap: wrap;
  gap: 0 2.5rem;
  padding-top: 1.5rem;
  border-top: 1px solid var(--line);
}
.hero__meta dt {
  font-size: .8125rem;
  color: var(--fg-3);
  letter-spacing: .04em;
}
.hero__meta dd {
  font-size: 1.0625rem;
  font-weight: 600;
  color: var(--fg);
}

.hero__cta { margin-top: 2.6rem; display: flex; flex-wrap: wrap; gap: .75rem; }

.hero__mark { text-align: center; user-select: none; }
/* 숫자 10 과 비슷한 폭으로 맞춰 기념 마크처럼 쌓는다. */
.mark__logo {
  width: clamp(190px, 20vw, 285px);
  height: auto;
  margin: 0 auto 1.75rem;
}
.mark {
  font-size: clamp(7rem, 15vw, 13rem);
  font-weight: 800;
  line-height: .82;
  letter-spacing: -.06em;
  color: var(--fg);
}
.mark span { color: var(--accent); }
.mark__years {
  margin-top: 1rem;
  font-family: var(--mono);
  font-size: .875rem;
  letter-spacing: .22em;
  color: var(--fg-3);
}

/* ── Countdown ───────────────────────────────────────────── */

.countdown {
  border-block: 1px solid var(--line);
  background: var(--bg-alt);
}
.countdown__inner {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 1.25rem 2rem;
  padding-block: 2.1rem;
}
.countdown__head {
  font-size: .9375rem;
  font-weight: 600;
  color: var(--fg-3);
  letter-spacing: -.01em;
}
.countdown__clock { display: flex; gap: 1.5rem; margin-inline-end: auto; }
.countdown__clock li { display: flex; align-items: baseline; gap: .3rem; }
.countdown__clock .num {
  font-family: var(--mono);
  font-size: clamp(1.5rem, 3vw, 2rem);
  font-weight: 700;
  font-variant-numeric: tabular-nums;
  color: var(--fg);
  letter-spacing: -.02em;
}
.countdown__clock .unit { font-size: .8125rem; color: var(--fg-3); }
.countdown__over { margin-inline-end: auto; color: var(--fg-2); font-weight: 600; }

/* ── Section shell ───────────────────────────────────────── */

.section { padding-block: var(--pad-y); }
.section--alt { background: var(--bg-alt); border-block: 1px solid var(--line); }

.section__title {
  font-size: clamp(1.7rem, 3.2vw, 2.5rem);
  letter-spacing: -.035em;
}
.section__note {
  margin-top: 1.1rem;
  max-width: 62ch;
  color: var(--fg-3);
  font-size: .9375rem;
}

/* ── 행사 개요 (definition rows) ─────────────────────────── */

.facts { margin-top: clamp(2rem, 4vw, 3rem); border-top: 1px solid var(--line); }
.facts__row {
  display: grid;
  grid-template-columns: minmax(140px, 200px) minmax(0, 1fr);
  gap: .25rem 2rem;
  padding-block: 1.55rem;
  border-bottom: 1px solid var(--line);
}
.facts dt { color: var(--fg-3); font-size: .9375rem; }
.facts dd { color: var(--fg); font-weight: 500; }
.facts dd a { color: var(--accent); text-decoration: underline; text-underline-offset: 3px; }

/* ── 프로그램 (agenda) ───────────────────────────────────── */

.agenda { margin-top: clamp(2rem, 4vw, 3rem); }
.agenda__item {
  display: grid;
  grid-template-columns: 150px minmax(0, 1fr);
  gap: .35rem 2rem;
  padding: 1.8rem 0;
  border-bottom: 1px solid var(--line);
}
.agenda__item:first-child { border-top: 1px solid var(--line); }
.agenda__time {
  font-family: var(--mono);
  font-size: .9375rem;
  font-variant-numeric: tabular-nums;
  color: var(--accent);
  letter-spacing: -.02em;
  padding-top: .15rem;
}
.agenda__title { font-size: 1.0625rem; font-weight: 600; }
.agenda__desc { margin-top: .3rem; color: var(--fg-3); font-size: .9375rem; }

.agenda__item--break .agenda__time { color: var(--fg-3); }
.agenda__item--break .agenda__title { color: var(--fg-2); font-weight: 500; }

/* 초청강연 하위 발표 목록 */
.talks {
  margin-top: 1rem;
  counter-reset: talk;
  display: grid;
  gap: .7rem;
}
.talks__item {
  counter-increment: talk;
  position: relative;
  padding-inline-start: 2rem;
  max-width: 62ch;
}
.talks__item::before {
  content: counter(talk);
  position: absolute;
  inset-inline-start: 0;
  top: .1rem;
  font-family: var(--mono);
  font-size: .8125rem;
  color: var(--accent);
  font-variant-numeric: tabular-nums;
}
.talks__title { font-size: .9375rem; font-weight: 500; line-height: 1.5; color: var(--fg); }
.talks__who   { margin-top: .15rem; font-size: .875rem; color: var(--fg-3); }

.talks__note {
  margin-top: .9rem;
  padding-inline-start: 2rem;
  font-size: .8125rem;
  color: var(--fg-3);
}

.talks__item--tbd::before { color: var(--fg-3); }
.talks__item--tbd .talks__title { color: var(--fg-3); font-style: italic; }

/* ── 다음 10년 (Symbiotic AIR) ───────────────────────────── */

/* 위아래 섹션과 붙어도 구분되도록 이 섹션만 톤을 따로 쓴다. */
.next10 {
  position: relative;
  background:
    radial-gradient(80% 60% at 50% 0%, var(--accent-soft) 0%, transparent 60%),
    var(--surface);
  border-block: 1px solid var(--line);
}

.model { margin-top: clamp(2rem, 4vw, 3rem); }
.model__pair {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: clamp(.875rem, 1.6vw, 1.25rem);
}
.model__card,
.model__out {
  padding: clamp(1.35rem, 2.4vw, 1.9rem);
  background: var(--bg);
  border: 1px solid var(--line);
  border-radius: var(--r-box);
}
.model__card h3 { font-size: 1.0625rem; letter-spacing: -.02em; }
.model__card p  { margin-top: .55rem; color: var(--fg-2); font-size: .9375rem; }

/* 두 모델이 아래 결과로 모인다는 걸 세로선으로만 표시한다. */
.model__out {
  position: relative;
  margin-top: 3rem;
  border-color: rgba(198, 65, 15, .35);
  background: linear-gradient(180deg, var(--accent-soft), transparent 70%), var(--bg);
}
.model__out::before {
  content: "";
  position: absolute;
  left: 50%;
  top: -3rem;
  width: 1px;
  height: 3rem;
  background: linear-gradient(to bottom, transparent, var(--accent));
}
.model__out h3 { font-size: clamp(1.25rem, 2.2vw, 1.6rem); color: var(--accent); letter-spacing: -.03em; }
.model__out p  { margin-top: .7rem; max-width: 68ch; color: var(--fg-2); }

.loop__head {
  margin-top: clamp(2.75rem, 5vw, 4rem);
  font-size: 1.0625rem;
  letter-spacing: -.02em;
}
.loop {
  margin-top: 1rem;
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: .5rem .35rem;
  counter-reset: step;
}
.loop li {
  counter-increment: step;
  display: inline-flex;
  align-items: center;
  gap: .45rem;
  padding: .5rem .95rem;
  background: var(--bg);
  border: 1px solid var(--line);
  border-radius: var(--r-ui);
  font-size: .9375rem;
  font-weight: 600;
}
.loop li::before {
  content: counter(step);
  font-family: var(--mono);
  font-size: .75rem;
  font-weight: 700;
  color: var(--accent);
}
.loop__note { margin-top: 1.25rem; max-width: 72ch; color: var(--fg-3); font-size: .9375rem; }

.concepts {
  margin-top: clamp(2.75rem, 5vw, 4rem);
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: clamp(.875rem, 1.6vw, 1.25rem);
}
.concept {
  padding: clamp(1.35rem, 2.4vw, 1.9rem);
  background: var(--bg);
  border: 1px solid var(--line);
  border-radius: var(--r-box);
}
.concept h3 { font-size: 1.25rem; letter-spacing: -.02em; }
.concept__sub {
  margin-top: .4rem;
  font-family: var(--mono);
  font-size: .75rem;
  line-height: 1.6;
  color: var(--accent);
  letter-spacing: 0;
}
.concept > p:last-child { margin-top: .8rem; color: var(--fg-2); font-size: .9375rem; }

/* ── 비전 영상: 가로 스크롤 레일 ─────────────────────────── */

.vrail { margin-top: clamp(2rem, 4vw, 3rem); }

.vrail__track {
  display: flex;
  gap: clamp(.875rem, 1.6vw, 1.25rem);
  overflow-x: auto;
  overscroll-behavior-x: contain;
  scroll-snap-type: x mandatory;
  /* 스크롤 끝에서 카드가 컨테이너 가장자리에 붙게 한다. */
  padding-block-end: .875rem;
  scrollbar-width: thin;
  scrollbar-color: var(--line-hi) transparent;
}
.vrail__track::-webkit-scrollbar { height: 6px; }
.vrail__track::-webkit-scrollbar-track { background: var(--line); border-radius: 99px; }
.vrail__track::-webkit-scrollbar-thumb { background: var(--line-hi); border-radius: 99px; }
.vrail__track::-webkit-scrollbar-thumb:hover { background: var(--fg-3); }

.vcard {
  flex: 0 0 clamp(266px, 31vw, 400px);
  scroll-snap-align: start;
  display: flex;
  flex-direction: column;
}

.vcard__frame {
  position: relative;
  aspect-ratio: 16 / 9;
  border: 1px solid var(--line);
  border-radius: var(--r-box);
  overflow: hidden;
  background: var(--surface);
}
.vcard__frame iframe { width: 100%; height: 100%; border: 0; display: block; }

.vcard__btn {
  position: absolute;
  inset: 0;
  width: 100%;
  padding: 0;
  border: 0;
  background: none;
  cursor: pointer;
  display: block;
}
.vcard__btn img {
  width: 100%;
  height: 100%;
  object-fit: cover;
  opacity: .96;
  transition: opacity .3s var(--ease), transform .5s var(--ease);
}
.vcard__btn:hover img { opacity: 1; transform: scale(1.03); }

.vcard__icon {
  position: absolute;
  top: 50%;
  left: 50%;
  transform: translate(-50%, -50%);
  width: clamp(48px, 4.4vw, 60px);
  aspect-ratio: 1;
  display: grid;
  place-items: center;
  border-radius: 50%;
  background: var(--accent);
  color: var(--accent-ink);
  font-size: clamp(1.25rem, 1.8vw, 1.5rem);
  transition: transform .25s var(--ease), background-color .25s var(--ease);
}
.vcard__btn:hover .vcard__icon { transform: translate(-50%, -50%) scale(1.08); background: var(--accent-hi); }
.vcard__btn:active .vcard__icon { transform: translate(-50%, -50%) scale(.97); }

.vcard__title {
  margin-top: .8rem;
  font-size: .9375rem;
  font-weight: 600;
  line-height: 1.45;
  color: var(--fg);
}
.vcard__channel { margin-top: .25rem; font-size: .8125rem; color: var(--fg-3); }

.vrail__nav { display: flex; justify-content: flex-end; gap: .5rem; margin-top: 1rem; }
.vrail__btn {
  width: 42px;
  height: 42px;
  display: grid;
  place-items: center;
  background: transparent;
  border: 1px solid var(--line-hi);
  border-radius: var(--r-ui);
  color: var(--fg);
  font-size: 1.1rem;
  cursor: pointer;
  transition: border-color .18s var(--ease), background-color .18s var(--ease), opacity .18s var(--ease);
}
.vrail__btn:hover:not(:disabled) { border-color: var(--fg-3); background: rgba(27, 29, 33, .05); }
.vrail__btn:disabled { opacity: .3; cursor: default; }

/* ── 연구와 활동 (bento) ─────────────────────────────────── */

/* 줄 높이를 고정해야 큰 타일이 두 줄을 차지해도 빈 칸이 생기지 않는다. */
.bento {
  margin-top: clamp(2rem, 4vw, 3rem);
  display: grid;
  grid-template-columns: repeat(6, minmax(0, 1fr));
  grid-auto-rows: clamp(170px, 15vw, 215px);
  gap: clamp(.75rem, 1.6vw, 1.25rem);
}
.bento__cell {
  margin: 0;
  display: flex;
  flex-direction: column;
  min-height: 0;
}
.bento__cell[data-col="2"] { grid-column: span 2; }
.bento__cell[data-col="3"] { grid-column: span 3; }
.bento__cell[data-col="4"] { grid-column: span 4; }
.bento__cell[data-row="2"] { grid-row: span 2; }

.bento__frame {
  flex: 1 1 auto;
  min-height: 0;
  border: 1px solid var(--line);
  border-radius: var(--r-box);
  overflow: hidden;
  background: var(--surface);
}
.bento__frame img {
  width: 100%;
  height: 100%;
  object-fit: cover;
  display: block;
  transition: transform .55s var(--ease);
}
.bento__cell:hover .bento__frame img { transform: scale(1.03); }
.bento__cell--placeholder:hover .bento__frame img { transform: none; }

.bento__caption {
  margin-top: .7rem;
  color: var(--fg-2);
  font-size: .875rem;
}
.bento__cell--placeholder .bento__caption { color: var(--fg-3); }

/* ── 주최 · 주관 로고 ────────────────────────────────────── */

.orgs { padding-block: clamp(4.5rem, 8vw, 6.5rem); border-top: 1px solid var(--line); }
.orgs__title {
  font-size: .8125rem;
  font-weight: 700;
  color: var(--fg-3);
  letter-spacing: .1em;
}
.orgs__title + .orgs__list { margin-top: 1.25rem; }
.orgs__list + .orgs__title { margin-top: 2.75rem; }

.orgs__list {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(180px, 1fr));
  gap: .875rem;
}
/* 로고 원본이 대부분 밝은 배경용 마크라 밝은 타일 위에 올려 대비를 지킨다. */
.orgs__tile {
  display: grid;
  place-items: center;
  min-height: 104px;
  padding: 1.25rem 1.5rem;
  background: var(--surface);
  border: 1px solid var(--line);
  border-radius: var(--r-box);
}
.orgs__tile img { max-width: 100%; max-height: 58px; width: auto; object-fit: contain; }

/* 협력 기관은 수가 많아 타일을 한 단계 작게 쓴다. */
.orgs__list--sm { grid-template-columns: repeat(auto-fill, minmax(148px, 1fr)); }
.orgs__list--sm .orgs__tile { min-height: 84px; padding: .9rem 1.15rem; }
.orgs__list--sm .orgs__tile img { max-height: 42px; }

/* 줄바꿈이 어긋나지 않게 열 수를 고정하는 경우. */
.orgs__list--3 { grid-template-columns: repeat(3, minmax(0, 1fr)); }
.orgs__list--6 { grid-template-columns: repeat(6, minmax(0, 1fr)); }

/* 3열은 타일이 넓어져 기본 크기로는 로고가 묻힌다. */
.orgs__list--3 .orgs__tile { min-height: 124px; }
.orgs__list--3 .orgs__tile img { max-height: 76px; }

/* ── 10년의 발자취 (timeline) ────────────────────────────── */

.timeline {
  margin-top: clamp(2.5rem, 5vw, 3.5rem);
  position: relative;
  padding-inline-start: clamp(1.5rem, 4vw, 3rem);
  border-inline-start: 1px solid var(--line);
}
.tl__item { position: relative; padding-bottom: clamp(2.6rem, 5vw, 4rem); }
.tl__item:last-child { padding-bottom: 0; }

.tl__item::before {
  content: "";
  position: absolute;
  left: calc(clamp(1.5rem, 4vw, 3rem) * -1 - 1px);
  top: .7rem;
  width: 9px;
  height: 9px;
  background: var(--accent);
  border-radius: 50%;
  transform: translateX(-50%);
}

.tl__year {
  font-family: var(--mono);
  font-size: 1.375rem;
  font-weight: 700;
  color: var(--accent);
  letter-spacing: -.02em;
}
.tl__body { margin-top: .5rem; max-width: 58ch; }
.tl__title { font-size: 1.125rem; font-weight: 600; }
.tl__desc { margin-top: .4rem; color: var(--fg-2); }

.tl__figure {
  margin-top: 1rem;
  border: 1px solid var(--line);
  border-radius: var(--r-box);
  overflow: hidden;
  max-width: 560px;
}
.tl__figure img { width: 100%; height: auto; }

/* ── 오시는 길 ───────────────────────────────────────────── */

.venue {
  margin-top: clamp(2rem, 4vw, 3rem);
  display: grid;
  grid-template-columns: minmax(0, 1.15fr) minmax(0, .85fr);
  gap: clamp(1.5rem, 3vw, 2.5rem);
  align-items: start;
}
.venue__map {
  border: 1px solid var(--line);
  border-radius: var(--r-box);
  overflow: hidden;
  background: var(--surface);
}
.venue__map iframe { width: 100%; height: clamp(320px, 44vh, 440px); border: 0; }

.venue__info h3 {
  font-size: .8125rem;
  font-weight: 700;
  color: var(--fg-3);
  letter-spacing: .1em;
  text-transform: uppercase;
}
.venue__info h3 + * { margin-top: .65rem; }
.venue__info > h3:not(:first-child) { margin-top: 2rem; }

.venue__addr { font-size: 1.0625rem; font-weight: 500; line-height: 1.6; }
.venue__links a {
  display: inline-flex;
  align-items: center;
  gap: .4rem;
  margin-top: .75rem;
  color: var(--accent);
  font-size: .9375rem;
  font-weight: 600;
}
.venue__links a:hover { color: var(--accent-hi); }

.transit { display: grid; gap: .25rem; }
.transit li {
  display: flex;
  gap: .9rem;
  padding: .85rem 0;
  border-bottom: 1px solid var(--line);
}
.transit li:last-child { border-bottom: 0; }
.transit i { color: var(--fg-3); font-size: 1.25rem; line-height: 1.5; flex: none; }
.transit strong { display: block; font-weight: 600; font-size: .9375rem; }
.transit span { display: block; color: var(--fg-3); font-size: .9375rem; }

/* ── 참가 신청 CTA ───────────────────────────────────────── */

.register {
  padding-block: clamp(6rem, 10vw, 8.5rem);
  background: var(--bg-alt);
  border-top: 1px solid var(--line);
  text-align: center;
}
.register__inner { display: flex; flex-direction: column; align-items: center; }
.register h2 { font-size: clamp(1.75rem, 3.4vw, 2.5rem); letter-spacing: -.035em; }
.register p { margin-top: 1rem; max-width: 52ch; color: var(--fg-2); }
.register .btn { margin-top: 2rem; }
.register__deadline {
  margin-top: 1.25rem;
  font-family: var(--mono);
  font-size: .875rem;
  color: var(--fg-3);
}

/* ── Footer ──────────────────────────────────────────────── */

.foot { padding-block: clamp(4rem, 7vw, 6rem); border-top: 1px solid var(--line); }

.foot__cards {
  display: grid;
  /* 카드 수가 바뀌어도 줄이 자연스럽게 접히도록 auto-fit 을 쓴다. */
  grid-template-columns: repeat(auto-fit, minmax(230px, 1fr));
  gap: 1rem;
}
.fcard {
  position: relative;
  display: flex;
  flex-direction: column;
  gap: .3rem;
  padding: 1.35rem 1.5rem;
  background: var(--surface);
  border: 1px solid var(--line);
  border-radius: var(--r-box);
  transition: border-color .2s var(--ease), background-color .2s var(--ease);
}
.fcard:hover { border-color: var(--line-hi); background: var(--surface-hi); }
.fcard__k { font-weight: 600; }
.fcard__v { font-family: var(--mono); font-size: .8125rem; color: var(--fg-3); }
.fcard i {
  position: absolute;
  top: 1.35rem;
  right: 1.4rem;
  color: var(--fg-3);
  font-size: 1.125rem;
}

.foot__base {
  margin-top: 2.5rem;
  padding-top: 1.75rem;
  border-top: 1px solid var(--line);
  display: flex;
  flex-wrap: wrap;
  justify-content: space-between;
  gap: 1rem 2rem;
}
.foot__org { color: var(--fg-3); font-size: .875rem; line-height: 1.7; }
.foot__copy { color: var(--fg-3); font-size: .875rem; }

/* ── Scroll reveal ───────────────────────────────────────── */

.reveal { opacity: 0; transform: translateY(18px); }
.reveal.is-in {
  opacity: 1;
  transform: none;
  transition: opacity .65s var(--ease), transform .65s var(--ease);
}

/* ── Responsive ──────────────────────────────────────────── */

@media (max-width: 1024px) {
  .hero__inner { grid-template-columns: minmax(0, 1.5fr) minmax(0, .5fr); }
  .venue { grid-template-columns: minmax(0, 1fr); }

  /* 6칸을 4칸으로 접는다. 넓은 타일만 한 줄을 다 쓰고 나머지는 2칸씩
     짝을 지어 빈 칸이 생기지 않게 한다. */
  .bento { grid-template-columns: repeat(4, minmax(0, 1fr)); }
  .bento__cell[data-col="4"] { grid-column: span 4; }
  .bento__cell[data-col="3"],
  .bento__cell[data-col="2"] { grid-column: span 2; }

  /* 협력 12곳을 6+6 대신 4+4+4 로 떨어뜨린다. */
  .orgs__list--6 { grid-template-columns: repeat(4, minmax(0, 1fr)); }
}

@media (max-width: 860px) {
  .burger { display: inline-flex; }

  .nav__links {
    position: fixed;
    inset: var(--nav-h) 0 auto;
    flex-direction: column;
    align-items: stretch;
    gap: 0;
    margin: 0;
    padding: .5rem clamp(1.25rem, 4vw, 2.5rem) 1.25rem;
    background: rgba(247, 246, 243, .98);
    border-bottom: 1px solid var(--line);
    font-size: 1rem;
    display: none;
  }
  .nav__links.is-open { display: flex; }
  .nav__links a { padding: .9rem 0; border-bottom: 1px solid var(--line); color: var(--fg); }
  .nav__links a:last-child { border-bottom: 0; }

  .nav .btn--sm { display: none; }

  .hero { min-height: 0; }
  .hero__inner { grid-template-columns: minmax(0, 1fr); }
  .hero__mark { display: none; }
  .hero__meta { gap: 1rem 2rem; }
  .hero__meta > div { min-width: 45%; }

  .countdown__inner { gap: 1rem 1.5rem; }
  .countdown__clock { gap: 1.1rem; }
  .countdown .btn { width: 100%; }

  .facts__row { grid-template-columns: minmax(0, 1fr); gap: .2rem; }
  .agenda__item { grid-template-columns: minmax(0, 1fr); gap: .3rem; }

  .foot__cards { grid-template-columns: minmax(0, 1fr); }

  /* 좁은 화면에서는 한 줄에 하나씩. 높이는 16:9 로 통일한다. */
  .model__pair,
  .concepts { grid-template-columns: minmax(0, 1fr); }
  .model__out { margin-top: 2.25rem; }
  .model__out::before { top: -2.25rem; height: 2.25rem; }

  .bento { grid-template-columns: minmax(0, 1fr); grid-auto-rows: auto; }
  .bento__cell { grid-column: 1 / -1 !important; grid-row: auto !important; }
  .bento__frame { aspect-ratio: 16 / 9; flex: none; }

  .orgs__list { grid-template-columns: repeat(auto-fill, minmax(140px, 1fr)); }
  .orgs__tile { min-height: 84px; padding: 1rem 1.15rem; }
  .orgs__tile img { max-height: 42px; }
  .orgs__list--sm { grid-template-columns: repeat(auto-fill, minmax(112px, 1fr)); }
  .orgs__list--sm .orgs__tile { min-height: 68px; padding: .7rem .85rem; }
  .orgs__list--sm .orgs__tile img { max-height: 32px; }
  /* 좁은 화면에서는 3열이 너무 눌린다. 후원 2+2+2, 협력 3+3+3+3. */
  .orgs__list--3 { grid-template-columns: repeat(2, minmax(0, 1fr)); }
  .orgs__list--6 { grid-template-columns: repeat(3, minmax(0, 1fr)); }

  .vcard { flex-basis: 78vw; }
}

@media (max-width: 480px) {
  .countdown__clock { width: 100%; justify-content: space-between; gap: .5rem; }
  .hero__cta .btn { flex: 1 1 auto; }
}

/* ── Reduced motion ──────────────────────────────────────── */

@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }
  *, *::before, *::after {
    animation-duration: .001ms !important;
    animation-iteration-count: 1 !important;
    transition-duration: .001ms !important;
  }
  .reveal { opacity: 1; transform: none; }
}