.page-about {
  --ab-wrap: 720px;
}

/* ---------- breadcrumbs & hero ---------- */

.page-about .ab-breadcrumbs {
  padding-top: clamp(1.25rem, 3vw, 2rem);
}

.page-about .ab-hero {
  padding-top: clamp(2rem, 5vw, 3.25rem);
  padding-bottom: clamp(2.5rem, 7vw, 5rem);
}

.page-about .ab-hero__title {
  margin: 1rem 0 0;
  max-width: 20ch;
  font-size: clamp(2rem, 7.2vw, 4.25rem);
  font-weight: 300;
  line-height: 1.08;
  letter-spacing: -0.03em;
  color: var(--white);
}

.page-about .ab-hero__lead {
  margin-top: clamp(1.25rem, 3vw, 1.75rem);
  max-width: var(--ab-wrap);
}

.page-about .ab-hero__facts {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 1px;
  margin-top: clamp(2rem, 5vw, 3.25rem);
  background: var(--line);
  border: 1px solid var(--line);
}

@media (min-width: 780px) {
  .page-about .ab-hero__facts {
    grid-template-columns: 1.1fr 1.6fr 1.7fr 1fr;
  }
}

.page-about .ab-fact {
  display: flex;
  flex-direction: column;
  gap: 0.5rem;
  min-height: 7.5rem;
  padding: clamp(1rem, 2.6vw, 1.5rem);
  background: var(--panel);
}

.page-about .ab-fact__num {
  font-family: var(--font-mono);
  font-size: clamp(1.6rem, 5.4vw, 2.4rem);
  font-weight: 700;
  line-height: 1;
  letter-spacing: -0.02em;
  color: var(--white);
}

.page-about .ab-fact--yellow .ab-fact__num {
  color: var(--yellow);
}

.page-about .ab-fact--lime .ab-fact__num {
  color: var(--lime);
}

.page-about .ab-fact__label {
  font-size: 0.8125rem;
  line-height: 1.7;
  color: var(--grey);
}

/* ---------- chapter head ---------- */

.page-about .ab-block {
  padding-bottom: clamp(3rem, 8vw, 5.5rem);
}

.page-about .ab-chapter {
  display: grid;
  gap: 0.65rem;
  margin-bottom: clamp(1.5rem, 4vw, 2.25rem);
  padding-top: clamp(1.25rem, 3vw, 2rem);
  border-top: 1px solid var(--line);
}

@media (min-width: 760px) {
  .page-about .ab-chapter {
    grid-template-columns: 5rem minmax(0, 1fr);
    align-items: start;
    gap: 1.5rem;
  }
}

.page-about .ab-chapter__num {
  padding-top: 0.35rem;
  font-family: var(--font-mono);
  font-size: 0.8125rem;
  font-weight: 600;
  letter-spacing: 0.2em;
  color: var(--turf);
}

.page-about .ab-chapter__title {
  margin: 0;
  max-width: 24ch;
  font-size: clamp(1.6rem, 4.6vw, 2.75rem);
  font-weight: 300;
  line-height: 1.18;
  letter-spacing: -0.02em;
  color: var(--white);
}

.page-about .ab-block__lead {
  max-width: var(--ab-wrap);
  margin-bottom: clamp(1.5rem, 4vw, 2.25rem);
}

.page-about .prose {
  max-width: var(--ab-wrap);
}

/* ---------- media ---------- */

.page-about .media-frame img {
  display: block;
  max-width: 100%;
}

.page-about .ab-who__media,
.page-about .ab-sourcing__media,
.page-about .ab-reach__media {
  margin: 0 0 clamp(1.5rem, 4vw, 2.25rem);
  aspect-ratio: 3 / 2;
}

.page-about .ab-reach__media {
  aspect-ratio: 16 / 9;
}

.page-about .ab-who__media {
  margin-top: 1.5rem;
  margin-bottom: 0;
}

@media (min-width: 860px) {
  .page-about .ab-who__media {
    margin-top: 0.25rem;
  }
}

/* ---------- three-step flow ---------- */

.page-about .ab-flow {
  list-style: none;
  display: grid;
  gap: 1rem;
  margin: clamp(1.5rem, 4vw, 2.25rem) 0 0;
  padding: 0;
}

@media (min-width: 880px) {
  .page-about .ab-flow {
    grid-template-columns: repeat(3, minmax(0, 1fr));
    gap: 1.25rem;
  }
}

.page-about .ab-flow__card {
  position: relative;
  display: flex;
  flex-direction: column;
  gap: 0.6rem;
  padding: clamp(1.25rem, 3vw, 1.75rem);
  background: var(--panel);
  border: 1px solid var(--line);
}

.page-about .ab-flow__card::before {
  content: "";
  position: absolute;
  left: 0;
  top: 0;
  bottom: 0;
  width: 2px;
  background: linear-gradient(180deg, var(--turf), rgba(31, 164, 91, 0));
}

@media (min-width: 880px) {
  .page-about .ab-flow__card + .ab-flow__card::after {
    content: "";
    position: absolute;
    top: 50%;
    left: -1.25rem;
    width: 1.25rem;
    height: 1px;
    background: var(--line-strong);
  }
}

.page-about .ab-flow__step {
  font-family: var(--font-mono);
  font-size: 0.75rem;
  letter-spacing: 0.16em;
  color: var(--turf);
}

.page-about .ab-flow__title {
  margin: 0;
  font-size: 1.0625rem;
  font-weight: 600;
  line-height: 1.4;
  color: var(--white);
}

.page-about .ab-flow__text {
  margin: 0;
  font-size: 0.9375rem;
  line-height: 1.8;
  color: var(--grey);
}

.page-about .ab-note {
  max-width: var(--ab-wrap);
  margin: clamp(1.25rem, 3vw, 1.75rem) 0 0;
  padding-left: 1rem;
  border-left: 2px solid var(--turf);
  font-size: 0.9375rem;
  line-height: 1.85;
  color: var(--grey);
}

/* ---------- indicator definitions ---------- */

.page-about .ab-def {
  margin: 0;
  border-top: 1px solid var(--line);
}

.page-about .ab-def__row {
  display: grid;
  gap: 0.5rem;
  padding: clamp(1rem, 3vw, 1.5rem) 0;
  border-bottom: 1px solid var(--line);
}

@media (min-width: 800px) {
  .page-about .ab-def__row {
    grid-template-columns: 200px minmax(0, 1fr);
    gap: 2rem;
    align-items: baseline;
  }
}

.page-about .ab-def__term {
  display: flex;
  align-items: baseline;
  gap: 0.55rem;
  font-size: 1rem;
  font-weight: 600;
  color: var(--white);
}

.page-about .ab-def__k {
  padding: 0.1rem 0.35rem;
  font-family: var(--font-mono);
  font-size: 0.6875rem;
  font-weight: 700;
  letter-spacing: 0.08em;
  color: var(--yellow);
  border: 1px solid rgba(245, 197, 24, 0.35);
  white-space: nowrap;
}

.page-about .ab-def__desc {
  margin: 0;
  max-width: 64ch;
  font-size: 0.9375rem;
  line-height: 1.9;
  color: var(--grey);
}

/* ---------- version timeline ---------- */

.page-about .ab-tl__scroll {
  overflow-x: auto;
  padding-bottom: 0.5rem;
  -webkit-overflow-scrolling: touch;
}

.page-about .ab-tl {
  position: relative;
  display: flex;
  gap: clamp(0.75rem, 2.5vw, 1.5rem);
  min-width: 960px;
  margin: 0;
  padding: 0;
  list-style: none;
}

.page-about .ab-tl::before {
  content: "";
  position: absolute;
  top: 0.3125rem;
  left: 0;
  right: 0;
  height: 1px;
  background: linear-gradient(90deg, var(--turf), rgba(31, 164, 91, 0.1));
}

.page-about .ab-tl__item {
  position: relative;
  flex: 1 1 0;
  min-width: 150px;
  padding-top: 1.75rem;
}

.page-about .ab-tl__item::before {
  content: "";
  position: absolute;
  top: 0;
  left: 0;
  width: 0.625rem;
  height: 0.625rem;
  border-radius: 50%;
  background: var(--turf);
  box-shadow: 0 0 0 4px rgba(31, 164, 91, 0.15);
}

.page-about .ab-tl__ver {
  display: block;
  margin-bottom: 0.55rem;
  font-family: var(--font-mono);
  font-size: 0.75rem;
  letter-spacing: 0.12em;
  color: var(--turf);
}

.page-about .ab-tl__title {
  margin: 0 0 0.45rem;
  font-size: 1rem;
  font-weight: 600;
  line-height: 1.4;
  color: var(--white);
}

.page-about .ab-tl__text {
  margin: 0;
  max-width: 28ch;
  font-size: 0.875rem;
  line-height: 1.8;
  color: var(--grey);
}

/* ---------- reach ---------- */

.page-about .ab-reach__body .prose p {
  margin-top: 0;
}

@media (min-width: 860px) {
  .page-about .ab-reach__body {
    align-items: start;
  }
}

/* ---------- closing cta ---------- */

.page-about .ab-cta {
  display: grid;
  gap: 1.5rem;
  padding: clamp(1.5rem, 4vw, 2.75rem);
  background: linear-gradient(135deg, var(--panel) 0%, rgba(10, 17, 32, 0.55) 100%);
  border: 1px solid var(--line);
}

@media (min-width: 820px) {
  .page-about .ab-cta {
    grid-template-columns: minmax(0, 1.35fr) minmax(0, 1fr);
    align-items: center;
    gap: 2.5rem;
  }
}

.page-about .ab-cta__text {
  margin: 0 0 1.25rem;
  max-width: 46ch;
  font-size: clamp(1rem, 2vw, 1.0625rem);
  line-height: 1.85;
  color: var(--white);
}

.page-about .ab-cta__actions {
  display: flex;
  flex-wrap: wrap;
  gap: 0.75rem;
}

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

@media (min-width: 820px) {
  .page-about .ab-cta__list {
    padding-left: 2rem;
    border-top: 0;
    border-left: 1px solid var(--line);
  }
}

.page-about .ab-cta__list li {
  border-bottom: 1px solid var(--line-soft);
}

.page-about .ab-cta__list li:last-child {
  border-bottom: 0;
}

.page-about .ab-cta__list a {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 1rem;
  padding: 0.9rem 0;
  font-size: 0.9375rem;
  color: var(--white);
  text-decoration: none;
  transition: color 0.2s var(--ease), padding-left 0.2s var(--ease);
}

.page-about .ab-cta__list a:hover,
.page-about .ab-cta__list a:focus-visible {
  padding-left: 0.35rem;
  color: var(--lime);
}

/* ---------- responsive guards ---------- */

@media (max-width: 719px) {
  .page-about .col-5,
  .page-about .col-7,
  .page-about .col-9 {
    grid-column: 1 / -1;
  }
}

@media (max-width: 480px) {
  .page-about .ab-hero__facts {
    grid-template-columns: minmax(0, 1fr);
  }

  .page-about .ab-fact {
    min-height: 0;
  }
}

@media (prefers-reduced-motion: reduce) {
  .page-about .ab-cta__list a {
    transition: none;
  }
}