/* ================= page: about ================= */
.page-about {
  --about-shell: 1180px;
  --about-gutter: clamp(16px, 4vw, 40px);
  position: relative;
  background:
    radial-gradient(1080px 620px at 88% -6%, rgba(123, 77, 255, 0.26), transparent 62%),
    radial-gradient(760px 520px at 4% 16%, rgba(33, 243, 224, 0.1), transparent 60%),
    var(--ink-900);
  color: var(--text);
  font-family: var(--font-sans);
  line-height: 1.75;
  padding-bottom: clamp(40px, 7vw, 88px);
  overflow-x: clip;
}

.page-about .about-shell {
  width: min(100% - (var(--about-gutter) * 2), var(--about-shell));
  margin-inline: auto;
}

/* ---------- breadcrumb ---------- */
.page-about .about-crumb {
  padding-top: clamp(18px, 3.5vw, 32px);
}

.page-about .about-crumb ol {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 6px;
  margin: 0;
  padding: 0;
  list-style: none;
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.06em;
  color: var(--text-mute);
}

.page-about .about-crumb li + li::before {
  content: "/";
  margin-right: 6px;
  color: var(--line);
}

.page-about .about-crumb a {
  color: var(--text-mute);
  text-decoration: none;
  border-bottom: 1px solid var(--line);
  padding-bottom: 1px;
  transition: color 0.25s var(--ease), border-color 0.25s var(--ease);
}

.page-about .about-crumb a:hover,
.page-about .about-crumb a:focus-visible {
  color: var(--mint);
  border-bottom-color: var(--mint);
  outline: none;
}

/* ---------- intro ---------- */
.page-about .about-intro {
  padding-block: clamp(26px, 5vw, 52px) clamp(38px, 6vw, 76px);
}

.page-about .about-intro__grid {
  display: grid;
  gap: clamp(16px, 3vw, 28px);
}

.page-about .about-intro__eyebrow {
  margin: 0;
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.2em;
  color: var(--mint);
}

.page-about .about-intro__title {
  margin: 14px 0 0;
  font-size: clamp(33px, 7.2vw, 64px);
  line-height: 1.07;
  letter-spacing: -0.025em;
  font-weight: 900;
  max-width: 17ch;
}

.page-about .about-intro__lede {
  margin: clamp(16px, 3vw, 24px) 0 0;
  max-width: 47ch;
  font-size: clamp(14.5px, 2vw, 16.5px);
  line-height: 1.85;
  color: var(--text-mute);
}

.page-about .about-intro__rule {
  margin-top: clamp(24px, 4vw, 38px);
  height: 4px;
  width: min(240px, 45%);
  background: linear-gradient(90deg, var(--orange), var(--violet-a) 52%, var(--mint));
}

.page-about .about-note {
  display: none;
  writing-mode: vertical-rl;
  margin: 0;
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.34em;
  color: var(--text-mute);
  border-right: 2px solid var(--line);
  padding-right: 10px;
  max-height: 220px;
}

/* ---------- .page-about layout ---------- */
.page-about .about-body {
  display: grid;
  gap: clamp(24px, 4vw, 40px);
  padding-top: clamp(6px, 1.5vw, 14px);
}

/* ---------- chapter nav ---------- */
.page-about .about-toc {
  align-self: start;
  border: 2px solid var(--line);
  background: var(--ink-800);
  padding: 14px 16px;
  box-shadow: 6px 6px 0 0 rgba(4, 6, 26, 0.6);
}

.page-about .about-toc__title {
  margin: 0 0 10px;
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: 0.26em;
  color: var(--text-mute);
}

.page-about .about-toc ol {
  display: flex;
  gap: 6px;
  margin: 0;
  padding: 0;
  list-style: none;
  overflow-x: auto;
  scrollbar-width: thin;
}

.page-about .about-toc li {
  flex: 0 0 auto;
}

.page-about .about-toc a {
  display: flex;
  align-items: baseline;
  gap: 9px;
  padding: 8px 10px;
  color: var(--text-mute);
  text-decoration: none;
  font-size: 13px;
  white-space: nowrap;
  border-left: 2px solid transparent;
  transition: color 0.24s var(--ease), background-color 0.24s var(--ease), border-color 0.24s var(--ease);
}

.page-about .about-toc a:hover,
.page-about .about-toc a:focus-visible {
  color: var(--text);
  background: var(--ink-700);
  border-left-color: var(--orange);
  outline: none;
}

.page-about .about-toc a.is-active {
  color: var(--mint);
  border-left-color: var(--mint);
}

.page-about .about-toc__num {
  font-family: var(--font-mono);
  font-size: 11px;
  color: var(--mint);
  opacity: 0.85;
}

/* ---------- stage ---------- */
.page-about .about-flow {
  display: grid;
  gap: clamp(46px, 7vw, 92px);
  min-width: 0;
}

.page-about .about-stage {
  min-width: 0;
}

.page-about .about-stage__head {
  position: relative;
  display: flex;
  flex-wrap: wrap;
  align-items: baseline;
  gap: 8px 14px;
  padding-bottom: 12px;
  margin-bottom: clamp(18px, 3vw, 28px);
  border-bottom: 2px solid var(--line);
}

.page-about .about-stage__head::after {
  content: "";
  position: absolute;
  left: 0;
  bottom: -2px;
  width: 58px;
  height: 2px;
  background: var(--orange);
}

.page-about .about-stage__num {
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.18em;
  color: var(--mint);
}

.page-about .about-stage__title {
  flex: 1 1 260px;
  margin: 0;
  font-size: clamp(23px, 3.6vw, 36px);
  font-weight: 900;
  line-height: 1.18;
  letter-spacing: -0.015em;
}

.page-about .about-stage__kicker {
  flex: 1 1 100%;
  margin: 0;
  font-size: 13px;
  color: var(--text-mute);
}

/* ---------- prose ---------- */
.page-about .about-prose p {
  margin: 0 0 1em;
  max-width: 48ch;
  font-size: clamp(14.5px, 1.7vw, 16px);
  line-height: 1.85;
  color: var(--text-mute);
}

.page-about .about-prose p:last-child {
  margin-bottom: 0;
}

.page-about .about-prose a {
  color: var(--mint);
  text-decoration: none;
  border-bottom: 1px solid rgba(33, 243, 224, 0.45);
}

.page-about .about-prose a:hover,
.page-about .about-prose a:focus-visible {
  border-bottom-color: var(--mint);
  outline: none;
}

/* ---------- figures ---------- */
.page-about .about-figure {
  margin: 0;
  border: 2px solid var(--line);
  background: var(--ink-700);
  box-shadow: 8px 8px 0 0 var(--black);
  overflow: hidden;
}

.page-about .about-figure img {
  display: block;
  width: 100%;
  height: auto;
  object-fit: cover;
}

.page-about .about-figure figcaption {
  border-top: 2px solid var(--line);
  padding: 10px 12px;
  font-family: var(--font-mono);
  font-size: 12px;
  line-height: 1.65;
  color: var(--text-mute);
  background: var(--ink-800);
}

.page-about .about-figure--wide {
  margin-bottom: clamp(26px, 4vw, 44px);
}

/* ---------- team ---------- */
.page-about .about-team {
  display: grid;
  gap: clamp(20px, 3.5vw, 34px);
}

/* ---------- four blocks ---------- */
.page-about .about-quad {
  display: grid;
  gap: 14px;
  margin-top: clamp(20px, 3vw, 30px);
}

.page-about .about-quad__item {
  position: relative;
  border: 2px solid var(--line);
  background: var(--ink-800);
  padding: clamp(16px, 2.6vw, 24px);
  transition: transform 0.3s var(--ease), border-color 0.3s var(--ease), box-shadow 0.3s var(--ease);
}

.page-about .about-quad__item::before {
  content: "";
  position: absolute;
  inset: 0 auto 0 0;
  width: 4px;
  background: linear-gradient(180deg, var(--violet-a), var(--mint));
}

.page-about .about-quad__item:hover {
  transform: translateY(-4px);
  border-color: var(--mint);
  box-shadow: 6px 6px 0 0 rgba(33, 243, 224, 0.26);
}

.page-about .about-quad__no {
  margin: 0;
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.16em;
  color: var(--orange);
}

.page-about .about-quad__name {
  margin: 8px 0 8px;
  font-size: clamp(17px, 2.2vw, 20px);
  font-weight: 700;
  line-height: 1.35;
}

.page-about .about-quad__text {
  margin: 0;
  font-size: 14px;
  line-height: 1.78;
  color: var(--text-mute);
}

/* ---------- stats ---------- */
.page-about .about-stats {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 2px;
  background: var(--line);
  border: 2px solid var(--line);
  margin-bottom: clamp(20px, 3vw, 30px);
}

.page-about .about-stat {
  background: var(--ink-800);
  padding: clamp(16px, 2.6vw, 24px);
}

.page-about .about-stat__num {
  display: block;
  font-family: var(--font-mono);
  font-size: clamp(27px, 4.6vw, 42px);
  line-height: 1;
  letter-spacing: -0.02em;
  color: var(--mint);
}

.page-about .about-stat--alt .about-stat__num {
  color: var(--orange);
}

.page-about .about-stat__unit {
  font-size: 0.46em;
  color: var(--text-mute);
  margin-left: 4px;
  letter-spacing: 0;
}

.page-about .about-stat__label {
  display: block;
  margin-top: 10px;
  font-size: 13px;
  line-height: 1.65;
  color: var(--text-mute);
}

.page-about .about-scale {
  display: grid;
  gap: clamp(20px, 3.5vw, 34px);
}

/* ---------- timeline ---------- */
.page-about .about-timeline {
  position: relative;
  margin: 0;
  padding: 0 0 0 30px;
  list-style: none;
  display: grid;
  gap: 26px;
}

.page-about .about-timeline::before {
  content: "";
  position: absolute;
  left: 7px;
  top: 8px;
  bottom: 8px;
  width: 2px;
  background: linear-gradient(180deg, var(--orange), var(--mint) 55%, var(--violet-b));
}

.page-about .about-timeline__item {
  position: relative;
}

.page-about .about-timeline__dot {
  position: absolute;
  left: -30px;
  top: 10px;
  width: 16px;
  height: 16px;
  border-radius: 50%;
  background: var(--ink-900);
  border: 3px solid var(--orange);
  box-shadow: 0 0 0 4px rgba(255, 106, 43, 0.14);
  transition: transform 0.3s var(--ease), border-color 0.3s var(--ease), box-shadow 0.3s var(--ease);
}

.page-about .about-timeline__item:hover .about-timeline__dot {
  transform: scale(1.18);
  border-color: var(--mint);
  box-shadow: 0 0 0 8px rgba(33, 243, 224, 0.16);
}

.page-about .about-timeline__card {
  border: 2px solid var(--line);
  background: var(--ink-800);
  padding: clamp(16px, 2.6vw, 24px);
  transition: border-color 0.3s var(--ease);
}

.page-about .about-timeline__item:hover .about-timeline__card {
  border-color: var(--line);
  border-top-color: var(--mint);
}

.page-about .about-timeline__ver {
  margin: 0;
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.2em;
  color: var(--mint);
}

.page-about .about-timeline__title {
  margin: 8px 0 10px;
  font-size: clamp(17px, 2.3vw, 21px);
  font-weight: 700;
  line-height: 1.35;
}

.page-about .about-timeline__text {
  margin: 0;
  max-width: 52ch;
  font-size: 14.5px;
  line-height: 1.82;
  color: var(--text-mute);
}

.page-about .about-timeline__more {
  display: inline-block;
  margin-top: 12px;
  padding: 4px 9px;
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.03em;
  color: var(--amber);
  border: 1px dashed var(--line);
  transition: color 0.28s var(--ease), border-color 0.28s var(--ease), background-color 0.28s var(--ease);
}

.page-about .about-timeline__item:hover .about-timeline__more {
  border-color: var(--amber);
  background: rgba(255, 176, 32, 0.08);
}

/* ---------- partners ---------- */
.page-about .about-pair {
  display: grid;
  gap: 14px;
  margin-block: clamp(20px, 3vw, 30px);
}

.page-about .about-pair__item {
  border: 2px solid var(--line);
  background: var(--ink-800);
  padding: clamp(16px, 2.6vw, 24px);
  transition: transform 0.3s var(--ease), border-color 0.3s var(--ease), box-shadow 0.3s var(--ease);
}

.page-about .about-pair__item:hover {
  transform: translateY(-4px);
  border-color: var(--orange);
  box-shadow: 6px 6px 0 0 rgba(255, 106, 43, 0.22);
}

.page-about .about-pair__item h3 {
  margin: 0 0 8px;
  font-size: clamp(16px, 2vw, 19px);
  font-weight: 700;
}

.page-about .about-pair__item p {
  margin: 0;
  font-size: 14px;
  line-height: 1.78;
  color: var(--text-mute);
}

/* ---------- flow list ---------- */
.page-about .about-flowlist {
  margin: 0;
  padding: 0;
  list-style: none;
  border-top: 2px solid var(--line);
}

.page-about .about-flowlist li {
  display: grid;
  gap: 6px;
  padding: 18px 0;
  border-bottom: 2px solid var(--line);
}

.page-about .about-flowlist__step {
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.18em;
  color: var(--orange);
}

.page-about .about-flowlist__title {
  margin: 0 0 6px;
  font-size: clamp(16px, 2vw, 19px);
  font-weight: 700;
}

.page-about .about-flowlist__text {
  margin: 0;
  max-width: 54ch;
  font-size: 14.5px;
  line-height: 1.8;
  color: var(--text-mute);
}

/* ---------- next ---------- */
.page-about .about-next {
  margin-top: clamp(48px, 8vw, 96px);
  border-top: 2px solid var(--line);
  padding-top: clamp(24px, 4vw, 40px);
}

.page-about .about-next__label {
  margin: 0 0 14px;
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.26em;
  color: var(--text-mute);
}

.page-about .about-next__links {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
}

/* ============ responsive ============ */
@media (min-width: 700px) {
  .page-about .about-quad {
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }

  .page-about .about-pair {
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }

  .page-about .about-flowlist li {
    grid-template-columns: 78px minmax(0, 1fr);
    align-items: baseline;
    gap: 0 18px;
  }
}

@media (min-width: 820px) {
  .page-about .about-stats {
    grid-template-columns: repeat(4, minmax(0, 1fr));
  }
}

@media (min-width: 900px) {
  .page-about .about-intro__grid {
    grid-template-columns: minmax(0, 1fr) auto;
    align-items: end;
  }

  .page-about .about-note {
    display: block;
  }

  .page-about .about-team {
    grid-template-columns: minmax(0, 5fr) minmax(0, 6fr);
    align-items: start;
  }

  .page-about .about-scale {
    grid-template-columns: minmax(0, 6fr) minmax(0, 5fr);
    align-items: start;
  }
}

@media (min-width: 1024px) {
  .page-about .about-body {
    grid-template-columns: 200px minmax(0, 1fr);
    gap: clamp(36px, 5vw, 72px);
    align-items: start;
  }

  .page-about .about-toc {
    position: sticky;
    top: 108px;
  }

  .page-about .about-toc ol {
    flex-direction: column;
    gap: 2px;
    overflow: visible;
  }

  .page-about .about-toc li {
    flex: 1 1 auto;
  }
}

@media (prefers-reduced-motion: reduce) {
  .page-about .about-quad__item,
  .page-about .about-pair__item,
  .page-about .about-timeline__dot {
    transition: none;
  }

  .page-about .about-quad__item:hover,
  .page-about .about-pair__item:hover {
    transform: none;
  }
}