.page-about {
  --ab-gap: clamp(20px, 4vw, 40px);
  --ab-pad-y: clamp(44px, 8vw, 96px);
  background: var(--c-navy);
  color: var(--c-white);
  font-family: var(--font-body);
  overflow-x: clip;
}

.page-about .ab-h2 {
  margin: 0 0 16px;
  font-family: var(--font-display);
  font-size: clamp(1.75rem, 5.2vw, 3rem);
  line-height: 1.06;
  font-weight: 800;
  letter-spacing: -0.01em;
  color: var(--c-white);
}

.page-about .ab-sec {
  padding: var(--ab-pad-y) 0;
  border-top: 1px solid var(--c-line-soft);
}

.page-about .ab-head {
  max-width: 64ch;
  margin-bottom: clamp(24px, 4vw, 44px);
}

.page-about .ab-head--tight {
  margin-bottom: clamp(20px, 3vw, 32px);
}

.page-about .ab-head__text {
  margin: 0;
  color: var(--c-mist);
  font-size: 1rem;
  line-height: 1.7;
}

.page-about .ab-head .eyebrow {
  color: var(--c-cyan);
  margin-bottom: 12px;
}

/* ---------- hero ---------- */
.page-about .ab-hero {
  position: relative;
  padding: clamp(20px, 4vw, 36px) 0 clamp(48px, 8vw, 88px);
  background:
    radial-gradient(120% 90% at 92% -20%, rgba(55, 245, 224, 0.16), transparent 62%),
    radial-gradient(90% 80% at 4% 116%, rgba(255, 122, 26, 0.14), transparent 60%),
    var(--c-navy);
  overflow: hidden;
}

.page-about .ab-hero__grid {
  display: grid;
  gap: clamp(24px, 4vw, 48px);
  margin-top: clamp(20px, 4vw, 44px);
}

.page-about .ab-hero__title {
  margin: 0 0 20px;
  font-family: var(--font-display);
  font-size: clamp(2.5rem, 11vw, 6rem);
  line-height: 0.94;
  font-weight: 800;
  letter-spacing: -0.02em;
  transform: skewX(-3deg);
  transform-origin: left bottom;
}

.page-about .ab-hero__title em {
  font-style: normal;
  color: var(--c-cyan);
  display: inline-block;
}

.page-about .ab-hero__lede {
  max-width: 56ch;
  margin: 0;
  font-size: clamp(0.98rem, 2.2vw, 1.08rem);
  line-height: 1.78;
  color: var(--c-mist);
}

.page-about .ab-hero__board {
  position: relative;
  padding: 18px 18px 8px;
  background: var(--c-panel);
  border: 1px solid var(--c-line);
  border-radius: var(--r-m);
  box-shadow: 8px 8px 0 rgba(55, 245, 224, 0.08), 0 22px 46px rgba(0, 0, 0, 0.38);
}

.page-about .ab-hero__board::before {
  content: "";
  position: absolute;
  left: -1px;
  top: -10px;
  width: 66px;
  height: 10px;
  background: var(--c-orange);
  border-radius: 3px 3px 0 0;
}

.page-about .ab-hero__board-title {
  margin: 0 0 14px;
  font-family: var(--font-mono);
  font-size: 0.72rem;
  letter-spacing: 0.16em;
  text-transform: uppercase;
  color: var(--c-scale);
}

.page-about .ab-hero__stats {
  list-style: none;
  margin: 0;
  padding: 0;
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 14px 16px;
}

.page-about .ab-hero__stat {
  padding-top: 10px;
  border-top: 1px solid var(--c-line-soft);
}

.page-about .ab-hero__num {
  display: block;
  font-family: var(--font-mono);
  font-size: clamp(1.35rem, 4.6vw, 1.75rem);
  font-weight: 700;
  color: var(--c-cyan);
  line-height: 1.1;
}

.page-about .ab-hero__lab {
  display: block;
  margin-top: 6px;
  font-size: 0.8rem;
  line-height: 1.5;
  color: var(--c-mist);
}

.page-about .ab-hero__stripe {
  position: absolute;
  right: -18%;
  bottom: -60px;
  width: 78%;
  height: 140px;
  background: repeating-linear-gradient(
    115deg,
    rgba(55, 245, 224, 0.16) 0 14px,
    transparent 14px 46px
  );
  transform: rotate(-8deg);
  pointer-events: none;
}

/* ---------- origin ---------- */
.page-about .ab-sec--origin {
  background: var(--c-navy-2);
}

.page-about .ab-origin {
  display: grid;
  gap: clamp(24px, 4vw, 46px);
}

.page-about .ab-origin__text p {
  margin: 0 0 14px;
  font-size: 1rem;
  line-height: 1.78;
  color: var(--c-mist);
}

.page-about .ab-origin__note {
  padding-left: 14px;
  border-left: 3px solid var(--c-orange);
  color: var(--c-white) !important;
  font-size: 0.94rem !important;
}

.page-about .ab-origin__figure {
  margin: 0;
}

.page-about .media-frame {
  margin: 0;
  border: 1px solid var(--c-line);
  border-radius: var(--r-m);
  overflow: hidden;
  background: var(--c-panel);
}

.page-about .media-frame__img {
  display: block;
  width: 100%;
  max-width: 100%;
  height: auto;
  object-fit: cover;
}

.page-about .media-frame__caption {
  padding: 12px 16px;
  font-family: var(--font-mono);
  font-size: 0.72rem;
  letter-spacing: 0.04em;
  line-height: 1.6;
  color: var(--c-scale);
  border-top: 1px solid var(--c-line-soft);
}

/* ---------- timeline ---------- */
.page-about .ab-jump {
  display: flex;
  gap: 8px;
  overflow-x: auto;
  padding-bottom: 10px;
  margin-bottom: clamp(22px, 4vw, 38px);
  border-bottom: 1px solid var(--c-line-soft);
  scrollbar-width: thin;
}

.page-about .ab-jump__link {
  flex: 0 0 auto;
  padding: 7px 14px;
  font-family: var(--font-mono);
  font-size: 0.8rem;
  letter-spacing: 0.06em;
  text-decoration: none;
  color: var(--c-mist);
  border: 1px solid var(--c-line);
  border-radius: var(--r-pill);
  transition: color var(--dur) var(--ease), border-color var(--dur) var(--ease),
    background-color var(--dur) var(--ease);
}

.page-about .ab-jump__link:hover,
.page-about .ab-jump__link:focus-visible {
  color: var(--c-navy);
  background: var(--c-cyan);
  border-color: var(--c-cyan);
  outline: none;
}

.page-about .ab-jump__link--hot {
  color: var(--c-orange);
  border-color: rgba(255, 122, 26, 0.5);
}

.page-about .ab-jump__link--hot:hover,
.page-about .ab-jump__link--hot:focus-visible {
  color: var(--c-navy);
  background: var(--c-orange);
  border-color: var(--c-orange);
}

.page-about .ab-track {
  display: grid;
  gap: clamp(24px, 4vw, 40px);
}

.page-about .ab-tl {
  list-style: none;
  margin: 0;
  padding: 0;
}

.page-about .ab-tl__item {
  position: relative;
  padding-left: 34px;
  padding-bottom: 20px;
}

.page-about .ab-tl__item::before {
  content: "";
  position: absolute;
  left: 9px;
  top: 10px;
  bottom: -10px;
  width: 2px;
  background: linear-gradient(180deg, rgba(55, 245, 224, 0.55), rgba(107, 124, 147, 0.28));
}

.page-about .ab-tl__item:last-child {
  padding-bottom: 0;
}

.page-about .ab-tl__item:last-child::before {
  display: none;
}

.page-about .ab-tl__dot {
  position: absolute;
  left: 0;
  top: 4px;
  width: 20px;
  height: 20px;
  border-radius: 50%;
  border: 2px solid var(--c-cyan);
  background: var(--c-navy);
  box-sizing: border-box;
}

.page-about .ab-tl__dot--key {
  border-color: var(--c-orange);
  background: var(--c-orange);
  box-shadow: 0 0 0 4px rgba(255, 122, 26, 0.18);
}

.page-about .ab-tl__ver {
  display: block;
  margin-bottom: 8px;
  font-family: var(--font-mono);
  font-size: 1.15rem;
  font-weight: 700;
  letter-spacing: 0.04em;
  color: var(--c-cyan);
}

.page-about .ab-tl__ver--key {
  color: var(--c-orange);
  font-size: 1.3rem;
}

.page-about .ab-card {
  position: relative;
  background: var(--c-panel);
  border: 1px solid var(--c-line);
  border-radius: var(--r-m);
  padding: 16px 18px 18px;
  box-shadow: 6px 6px 0 rgba(55, 245, 224, 0.06), 0 16px 34px rgba(0, 0, 0, 0.3);
  transition: border-color var(--dur) var(--ease), transform var(--dur) var(--ease),
    box-shadow var(--dur) var(--ease);
}

.page-about .ab-card:hover {
  border-color: rgba(55, 245, 224, 0.55);
  transform: translate(-2px, -2px);
  box-shadow: 10px 10px 0 rgba(55, 245, 224, 0.1), 0 18px 38px rgba(0, 0, 0, 0.36);
}

.page-about .ab-card--key {
  border-color: rgba(255, 122, 26, 0.42);
  background: linear-gradient(160deg, rgba(255, 122, 26, 0.1), transparent 62%), var(--c-panel);
}

.page-about .ab-card__title {
  margin: 10px 0 8px;
  font-family: var(--font-display);
  font-size: 1.22rem;
  font-weight: 700;
  line-height: 1.24;
  color: var(--c-white);
}

.page-about .ab-card p {
  margin: 0;
  font-size: 0.94rem;
  line-height: 1.72;
  color: var(--c-mist);
}

.page-about .ab-track__figure {
  margin: 0;
}

/* ---------- data editing ---------- */
.page-about .ab-sec--data {
  background: var(--c-navy-2);
}

.page-about .ab-data {
  display: grid;
  gap: clamp(24px, 4vw, 46px);
}

.page-about .ab-data__text > p {
  margin: 0 0 18px;
  font-size: 1rem;
  line-height: 1.78;
  color: var(--c-mist);
}

.page-about .ab-steps {
  list-style: none;
  margin: 0;
  padding: 0;
  display: grid;
  gap: 12px;
}

.page-about .ab-step {
  display: grid;
  grid-template-columns: 40px minmax(0, 1fr);
  gap: 12px;
  padding: 14px 16px;
  background: rgba(19, 43, 69, 0.72);
  border-left: 2px solid var(--c-cyan);
  border-radius: 0 var(--r-s) var(--r-s) 0;
}

.page-about .ab-step__num {
  font-family: var(--font-mono);
  font-size: 1.05rem;
  font-weight: 700;
  color: var(--c-cyan);
  line-height: 1.4;
}

.page-about .ab-step__title {
  margin: 0 0 4px;
  font-size: 1rem;
  font-weight: 700;
  color: var(--c-white);
}

.page-about .ab-step p {
  margin: 0;
  font-size: 0.9rem;
  line-height: 1.65;
  color: var(--c-mist);
}

.page-about .ab-data__figure {
  margin: 0;
  align-self: start;
}

/* ---------- team ---------- */
.page-about .ab-team {
  list-style: none;
  margin: 0;
  padding: 0;
  display: grid;
  gap: 14px;
}

.page-about .ab-team__item {
  position: relative;
  padding: 20px 18px 22px;
  background: var(--c-panel);
  border: 1px solid var(--c-line);
  border-radius: var(--r-m);
  overflow: hidden;
}

.page-about .ab-team__item::after {
  content: "";
  position: absolute;
  right: -22px;
  top: -22px;
  width: 62px;
  height: 62px;
  border: 2px solid rgba(55, 245, 224, 0.28);
  transform: rotate(45deg);
}

.page-about .ab-team__num {
  display: block;
  font-family: var(--font-mono);
  font-size: clamp(2rem, 7vw, 2.8rem);
  font-weight: 700;
  line-height: 1;
  color: var(--c-cyan);
}

.page-about .ab-team__title {
  margin: 10px 0 8px;
  font-family: var(--font-display);
  font-size: 1.2rem;
  font-weight: 700;
  color: var(--c-white);
}

.page-about .ab-team__item p {
  margin: 0;
  font-size: 0.92rem;
  line-height: 1.7;
  color: var(--c-mist);
}

.page-about .ab-team__foot {
  margin: 20px 0 0;
  padding: 16px 18px;
  font-size: 0.94rem;
  line-height: 1.75;
  color: var(--c-white);
  background: linear-gradient(100deg, rgba(55, 245, 224, 0.12), transparent 70%);
  border-left: 3px solid var(--c-cyan);
  border-radius: 0 var(--r-s) var(--r-s) 0;
}

/* ---------- cooperation ---------- */
.page-about .ab-sec--coop {
  background: var(--c-navy-2);
}

.page-about .ab-coop {
  display: grid;
  gap: 14px;
}

.page-about .ab-coop__item {
  position: relative;
  padding: 20px 18px;
  background: var(--c-panel);
  border: 1px solid var(--c-line);
  border-radius: var(--r-m);
}

.page-about .ab-coop__item--accent {
  border-color: rgba(255, 122, 26, 0.45);
  background: linear-gradient(150deg, rgba(255, 122, 26, 0.13), transparent 66%), var(--c-panel);
}

.page-about .ab-coop__num {
  display: block;
  font-family: var(--font-mono);
  font-size: clamp(1.9rem, 6.5vw, 2.5rem);
  font-weight: 700;
  line-height: 1;
  color: var(--c-orange);
}

.page-about .ab-coop__badge {
  display: inline-block;
  padding: 4px 10px;
  font-family: var(--font-mono);
  font-size: 0.7rem;
  letter-spacing: 0.12em;
  color: var(--c-navy);
  background: var(--c-orange);
  border-radius: var(--r-pill);
}

.page-about .ab-coop__title {
  margin: 10px 0 8px;
  font-family: var(--font-display);
  font-size: 1.2rem;
  font-weight: 700;
  line-height: 1.3;
  color: var(--c-white);
}

.page-about .ab-coop__item p {
  margin: 0;
  font-size: 0.92rem;
  line-height: 1.72;
  color: var(--c-mist);
}

.page-about .ab-coop__foot {
  margin: 18px 0 0;
  font-size: 0.94rem;
  line-height: 1.75;
  color: var(--c-mist);
}

/* ---------- method ---------- */
.page-about .ab-method {
  list-style: none;
  margin: 0;
  padding: 0;
  display: grid;
  gap: 12px;
  counter-reset: none;
}

.page-about .ab-method__item {
  position: relative;
  padding: 18px 18px 18px 58px;
  background: var(--c-navy-2);
  border: 1px solid var(--c-line-soft);
  border-radius: var(--r-m);
  transition: border-color var(--dur) var(--ease), background-color var(--dur) var(--ease);
}

.page-about .ab-method__item:hover {
  border-color: rgba(55, 245, 224, 0.5);
  background: var(--c-panel);
}

.page-about .ab-method__idx {
  position: absolute;
  left: 16px;
  top: 18px;
  font-family: var(--font-mono);
  font-size: 0.86rem;
  font-weight: 700;
  color: var(--c-orange);
}

.page-about .ab-method__title {
  margin: 0 0 6px;
  font-family: var(--font-display);
  font-size: 1.16rem;
  font-weight: 700;
  color: var(--c-white);
}

.page-about .ab-method__item p {
  margin: 0;
  font-size: 0.92rem;
  line-height: 1.7;
  color: var(--c-mist);
}

.page-about .ab-method__foot {
  margin: 18px 0 0;
  font-size: 0.94rem;
  line-height: 1.75;
  color: var(--c-mist);
}

/* ---------- open days ---------- */
.page-about .ab-sec--days {
  background: var(--c-navy-2);
}

.page-about .ab-days {
  display: grid;
  gap: clamp(22px, 4vw, 44px);
}

.page-about .ab-days__text p {
  margin: 0 0 14px;
  font-size: 1rem;
  line-height: 1.78;
  color: var(--c-mist);
}

.page-about .ab-days__list {
  list-style: none;
  margin: 0;
  padding: 0;
  display: grid;
  gap: 0;
  border-top: 1px solid var(--c-line);
}

.page-about .ab-days__item {
  display: grid;
  gap: 4px;
  padding: 14px 0;
  border-bottom: 1px dashed var(--c-line);
}

.page-about .ab-days__k {
  font-family: var(--font-mono);
  font-size: 0.78rem;
  letter-spacing: 0.12em;
  color: var(--c-cyan);
}

.page-about .ab-days__v {
  font-size: 0.94rem;
  line-height: 1.68;
  color: var(--c-white);
}

/* ---------- cta ---------- */
.page-about .ab-sec--cta {
  padding-bottom: clamp(52px, 9vw, 104px);
  background:
    radial-gradient(90% 130% at 100% 0%, rgba(55, 245, 224, 0.14), transparent 62%),
    var(--c-navy);
}

.page-about .ab-cta {
  display: grid;
  gap: 22px;
  padding: clamp(22px, 4vw, 40px);
  border: 1px solid var(--c-line);
  border-radius: var(--r-l);
  background: rgba(13, 33, 56, 0.7);
}

.page-about .ab-cta__text .eyebrow {
  color: var(--c-cyan);
  margin-bottom: 12px;
}

.page-about .ab-cta__text p {
  margin: 0;
  font-size: 0.98rem;
  line-height: 1.75;
  color: var(--c-mist);
  max-width: 52ch;
}

.page-about .ab-cta__actions {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 12px;
}

.page-about .ab-cta__actions .btn {
  text-decoration: none;
}

.page-about .ab-origin__text a.link-arrow,
.page-about .ab-method__foot a.link-arrow,
.page-about .ab-days__text a.link-arrow,
.page-about .ab-coop__foot a.link-arrow {
  color: var(--c-cyan);
}

.page-about .ab-origin__text a.link-arrow:hover,
.page-about .ab-method__foot a.link-arrow:hover,
.page-about .ab-days__text a.link-arrow:hover,
.page-about .ab-coop__foot a.link-arrow:hover,
.page-about .ab-coop__foot a.link-arrow:focus-visible,
.page-about .ab-days__text a.link-arrow:focus-visible {
  color: var(--c-orange);
}

/* ---------- desktop ---------- */
@media (min-width: 860px) {
  .page-about .ab-hero__grid {
    grid-template-columns: minmax(0, 1.35fr) minmax(0, 0.85fr);
    align-items: end;
  }

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

  .page-about .ab-origin {
    grid-template-columns: minmax(0, 1.02fr) minmax(0, 0.98fr);
    align-items: center;
  }

  .page-about .ab-track {
    grid-template-columns: minmax(0, 1.55fr) minmax(0, 0.85fr);
    align-items: start;
  }

  .page-about .ab-tl__item {
    padding-left: 150px;
  }

  .page-about .ab-tl__item:nth-child(even) {
    padding-left: 176px;
  }

  .page-about .ab-tl__item::before {
    left: 126px;
  }

  .page-about .ab-tl__item:nth-child(even)::before {
    left: 152px;
  }

  .page-about .ab-tl__dot {
    left: 117px;
    top: 6px;
  }

  .page-about .ab-tl__item:nth-child(even) .ab-tl__dot {
    left: 143px;
  }

  .page-about .ab-tl__ver {
    position: absolute;
    left: 0;
    top: 2px;
    margin-bottom: 0;
    font-size: 1.35rem;
  }

  .page-about .ab-tl__ver--key {
    font-size: 1.5rem;
  }

  .page-about .ab-data {
    grid-template-columns: minmax(0, 1.08fr) minmax(0, 0.92fr);
    align-items: start;
  }

  .page-about .ab-team {
    grid-template-columns: repeat(3, minmax(0, 1fr));
  }

  .page-about .ab-coop {
    grid-template-columns: repeat(3, minmax(0, 1fr));
  }

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

  .page-about .ab-days {
    grid-template-columns: minmax(0, 1.1fr) minmax(0, 0.9fr);
    align-items: start;
  }

  .page-about .ab-cta {
    grid-template-columns: minmax(0, 1.2fr) minmax(0, 0.8fr);
    align-items: center;
  }

  .page-about .ab-cta__actions {
    justify-content: flex-end;
  }
}

@media (min-width: 1180px) {
  .page-about .ab-hero__board {
    padding: 24px 24px 10px;
  }

  .page-about .ab-method {
    grid-template-columns: repeat(4, minmax(0, 1fr));
  }
}

@media (prefers-reduced-motion: reduce) {
  .page-about .ab-card,
  .page-about .ab-jump__link,
  .page-about .ab-method__item {
    transition: none;
  }

  .page-about .ab-card:hover {
    transform: none;
  }
}