.page-about {
  --ab-rail: 200px;
  --ab-gap: 44px;
  position: relative;
  display: block;
  padding-bottom: 104px;
  background-color: var(--c-bg);
  background-image:
    linear-gradient(to right, rgba(27, 42, 62, 0.42) 1px, transparent 1px),
    linear-gradient(to bottom, rgba(27, 42, 62, 0.42) 1px, transparent 1px);
  background-size: 96px 96px;
  color: var(--c-silver);
  font-family: var(--font-sans);
}

/* ---------- hero ---------- */

.page-about .ab-hero {
  padding: 30px 0 52px;
  border-bottom: 1px solid var(--c-line);
}

.page-about .breadcrumb {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 8px;
  font-size: 12.5px;
  color: var(--c-grey);
}

.page-about .breadcrumb a {
  color: var(--c-grey);
  text-decoration: none;
  border-bottom: 1px solid transparent;
  transition: color 180ms var(--ease), border-color 180ms var(--ease);
}

.page-about .breadcrumb a:hover {
  color: var(--c-cyan);
  border-bottom-color: rgba(63, 217, 232, 0.5);
}

.page-about .breadcrumb span[aria-current] {
  color: var(--c-silver);
}

.page-about .ab-hero__grid {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 34px;
  margin-top: 30px;
}

.page-about .ab-hero__lead {
  min-width: 0;
}

.page-about .ab-hero__title {
  margin: 14px 0 20px;
  font-family: var(--font-serif);
  font-weight: 600;
  font-size: clamp(30px, 6.2vw, 58px);
  line-height: 1.14;
  letter-spacing: -0.012em;
  color: var(--c-white);
  max-width: 16ch;
}

.page-about .ab-hero__lead .lede {
  margin: 0;
  max-width: 60ch;
  font-size: 16.5px;
  line-height: 1.85;
  color: var(--c-silver);
}

.page-about .ab-hero__actions {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
  margin-top: 26px;
}

.page-about .ab-hero__side {
  min-width: 0;
}

.page-about .ab-hero__stats {
  list-style: none;
  margin: 0;
  padding: 0;
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 1px;
  background: var(--c-line);
  border: 1px solid var(--c-line);
  border-radius: var(--radius);
  overflow: hidden;
}

.page-about .ab-hero__stats .stat {
  display: flex;
  flex-direction: column;
  gap: 8px;
  padding: 16px 16px 18px;
  background: var(--c-panel);
}

.page-about .ab-hero__stats .stat__label {
  font-size: 12px;
  line-height: 1.5;
  color: var(--c-grey);
}

.page-about .ab-hero__stats .stat__value {
  font-family: var(--font-mono);
  font-weight: 700;
  font-size: 30px;
  line-height: 1;
  letter-spacing: -0.02em;
  color: var(--c-lime);
}

.page-about .ab-hero__stats .stat__unit {
  font-family: var(--font-sans);
  font-size: 13px;
  font-weight: 400;
  margin-left: 3px;
  color: var(--c-grey);
}

.page-about .ab-hero__hint {
  margin: 14px 0 0;
  font-size: 13px;
  line-height: 1.75;
  color: var(--c-grey);
}

.page-about .ab-hero__hint .mono {
  color: var(--c-orange);
}

/* ---------- shell + rail ---------- */

.page-about .ab-shell {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 0;
}

.page-about .ab-rail {
  padding: 26px 0 0;
  min-width: 0;
}

.page-about .ab-rail__title {
  margin: 0 0 12px;
  font-size: 11px;
  letter-spacing: 0.2em;
  color: var(--c-grey);
}

.page-about .ab-rail__list {
  list-style: none;
  margin: 0;
  padding: 0 0 6px;
  display: flex;
  gap: 8px;
  overflow-x: auto;
  -webkit-overflow-scrolling: touch;
}

.page-about .ab-rail__link {
  flex: 0 0 auto;
  display: flex;
  align-items: baseline;
  gap: 8px;
  padding: 8px 12px;
  font-size: 13px;
  white-space: nowrap;
  color: var(--c-grey);
  text-decoration: none;
  background: var(--c-panel);
  border: 1px solid var(--c-line);
  border-radius: var(--radius);
  transition: color 180ms var(--ease), border-color 180ms var(--ease), background 180ms var(--ease);
}

.page-about .ab-rail__link .mono {
  font-size: 11px;
  color: var(--c-orange);
  letter-spacing: 0.06em;
  transition: color 180ms var(--ease);
}

.page-about .ab-rail__link:hover,
.page-about .ab-rail__link:focus-visible {
  color: var(--c-white);
  border-color: var(--c-green);
  background: var(--c-hi);
}

.page-about .ab-rail__link:hover .mono,
.page-about .ab-rail__link:focus-visible .mono {
  color: var(--c-green);
}

.page-about .ab-stream {
  min-width: 0;
  padding-top: 30px;
}

/* ---------- section head ---------- */

.page-about .ab-sec {
  padding: 46px 0 6px;
  scroll-margin-top: 110px;
}

.page-about .ab-head {
  position: relative;
  display: grid;
  grid-template-columns: auto minmax(0, 1fr);
  column-gap: 14px;
  row-gap: 10px;
  align-items: baseline;
  padding-bottom: 14px;
  margin-bottom: 28px;
  border-bottom: 1px solid var(--c-line);
}

.page-about .ab-head::after {
  content: "";
  position: absolute;
  left: 0;
  bottom: -1px;
  width: 72px;
  height: 2px;
  background: var(--c-green);
}

.page-about .ab-head__no {
  font-size: 13px;
  letter-spacing: 0.08em;
  color: var(--c-orange);
}

.page-about .ab-head__title {
  margin: 0;
  font-family: var(--font-sans);
  font-weight: 900;
  font-size: clamp(22px, 3.6vw, 32px);
  line-height: 1.2;
  letter-spacing: -0.012em;
  color: var(--c-white);
}

.page-about .ab-head__meta {
  grid-column: 1 / -1;
  margin: 0;
  max-width: 64ch;
  font-size: 14.5px;
  line-height: 1.8;
  color: var(--c-grey);
}

/* ---------- 01 beats ---------- */

.page-about .ab-beats {
  list-style: none;
  margin: 0;
  padding: 0;
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 1px;
  background: var(--c-line);
  border: 1px solid var(--c-line);
  border-radius: var(--radius);
  overflow: hidden;
}

.page-about .ab-beat {
  padding: 22px 20px 26px;
  background: var(--c-panel);
  transition: background 220ms var(--ease);
}

.page-about .ab-beat:hover {
  background: var(--c-hi);
}

.page-about .ab-beat__time {
  display: inline-block;
  margin-bottom: 14px;
  padding-bottom: 6px;
  font-size: 12px;
  letter-spacing: 0.06em;
  color: var(--c-orange);
  border-bottom: 1px solid rgba(255, 106, 31, 0.35);
}

.page-about .ab-beat__title {
  margin: 0 0 8px;
  font-size: 18px;
  font-weight: 700;
  letter-spacing: -0.01em;
  color: var(--c-white);
}

.page-about .ab-beat p {
  margin: 0;
  font-size: 15px;
  line-height: 1.78;
  color: var(--c-silver);
}

.page-about .ab-note {
  margin: 20px 0 0;
  font-size: 14px;
  line-height: 1.85;
  color: var(--c-grey);
}

.page-about .ab-note a {
  color: var(--c-cyan);
  text-decoration: none;
  border-bottom: 1px solid rgba(63, 217, 232, 0.4);
  transition: color 180ms var(--ease), border-color 180ms var(--ease);
}

.page-about .ab-note a:hover {
  color: var(--c-white);
  border-bottom-color: var(--c-white);
}

/* ---------- 02 team ---------- */

.page-about .ab-lead-text {
  margin: 0 0 26px;
  max-width: 62ch;
  font-size: 16px;
  line-height: 1.85;
  color: var(--c-silver);
}

.page-about .ab-exhibits {
  list-style: none;
  margin: 0 0 30px;
  padding: 0;
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 12px;
}

.page-about .ab-exhibit {
  padding: 20px 18px 22px;
  background: var(--c-panel);
  border: 1px solid var(--c-line);
  border-radius: var(--radius);
  transition: border-color 200ms var(--ease), transform 200ms var(--ease);
}

.page-about .ab-exhibit:hover {
  border-color: var(--c-green);
  transform: translateY(-2px);
}

.page-about .ab-exhibit__no {
  display: inline-block;
  margin-bottom: 14px;
  padding: 5px 8px;
  font-family: var(--font-mono);
  font-size: 12px;
  line-height: 1;
  color: var(--c-green);
  border: 1px solid var(--c-line);
  border-radius: 3px;
  transition: background 200ms var(--ease), color 200ms var(--ease), border-color 200ms var(--ease);
}

.page-about .ab-exhibit:hover .ab-exhibit__no {
  background: var(--c-green);
  border-color: var(--c-green);
  color: #04110c;
}

.page-about .ab-exhibit__name {
  margin: 0 0 8px;
  font-size: 17px;
  font-weight: 700;
  letter-spacing: -0.01em;
  color: var(--c-white);
}

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

.page-about .ab-exhibit p a {
  color: var(--c-cyan);
  text-decoration: none;
  border-bottom: 1px solid rgba(63, 217, 232, 0.4);
}

.page-about .ab-exhibit p a:hover {
  color: var(--c-white);
}

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

.page-about .ab-figure .figure-caption {
  margin-top: 10px;
}

/* ---------- 03 timeline ---------- */

.page-about .ab-timeline {
  list-style: none;
  margin: 0;
  padding: 4px 0 12px 26px;
  position: relative;
}

.page-about .ab-timeline::before {
  content: "";
  position: absolute;
  left: 6px;
  top: 12px;
  bottom: 26px;
  width: 1px;
  background: linear-gradient(to bottom, var(--c-green) 0%, rgba(0, 225, 140, 0.5) 55%, rgba(27, 42, 62, 0.9) 100%);
}

.page-about .ab-tl {
  position: relative;
  padding-bottom: 28px;
}

.page-about .ab-tl::before {
  content: "";
  position: absolute;
  left: -26px;
  top: 6px;
  width: 9px;
  height: 9px;
  border: 2px solid var(--c-green);
  border-radius: 50%;
  background: var(--c-bg);
  transition: transform 200ms var(--ease), background 200ms var(--ease);
}

.page-about .ab-tl:hover::before {
  background: var(--c-green);
  transform: scale(1.25);
}

.page-about .ab-tl__year {
  display: block;
  margin-bottom: 6px;
  font-size: 21px;
  font-weight: 700;
  letter-spacing: -0.02em;
  color: var(--c-orange);
}

.page-about .ab-tl__title {
  margin: 0 0 6px;
  font-size: 17px;
  font-weight: 700;
  letter-spacing: -0.01em;
  color: var(--c-white);
}

.page-about .ab-tl__desc {
  margin: 0;
  max-width: 58ch;
  font-size: 15px;
  line-height: 1.8;
  color: var(--c-silver);
}

.page-about .ab-tl__ver {
  display: inline-block;
  margin-top: 12px;
  padding: 4px 10px;
  font-size: 12px;
  color: var(--c-grey);
  border: 1px solid var(--c-line);
  border-radius: 999px;
  opacity: 0.55;
  transition: opacity 200ms var(--ease), color 200ms var(--ease), border-color 200ms var(--ease);
}

.page-about .ab-tl:hover .ab-tl__ver {
  opacity: 1;
  color: var(--c-cyan);
  border-color: rgba(63, 217, 232, 0.55);
}

.page-about .ab-figure--road {
  margin-top: 8px;
}

/* ---------- quiet band ---------- */

.page-about .ab-quiet {
  margin: 30px 0 8px;
  padding: 58px 0 62px;
  border-top: 1px solid var(--c-line);
  border-bottom: 1px solid var(--c-line);
}

.page-about .ab-quiet p {
  margin: 0;
  max-width: 30ch;
  font-family: var(--font-serif);
  font-weight: 600;
  font-size: clamp(20px, 3.8vw, 30px);
  line-height: 1.6;
  letter-spacing: -0.01em;
  color: var(--c-white);
}

/* ---------- 04 eco ---------- */

.page-about .ab-eco {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 30px;
}

.page-about .ab-eco__text p {
  margin: 0 0 1.2em;
  max-width: 56ch;
  font-size: 15.5px;
  line-height: 1.85;
  color: var(--c-silver);
}

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

.page-about .ab-bars {
  list-style: none;
  margin: 0;
  padding: 0;
  display: grid;
  gap: 16px;
  align-content: start;
}

.page-about .ab-bar {
  display: grid;
  grid-template-columns: minmax(0, 1fr) auto;
  gap: 8px 12px;
  align-items: center;
}

.page-about .ab-bar__label {
  font-size: 14px;
  color: var(--c-silver);
}

.page-about .ab-bar__val {
  font-size: 16px;
  font-weight: 700;
  color: var(--c-lime);
}

.page-about .ab-bar__track {
  grid-column: 1 / -1;
  height: 6px;
  background: var(--c-panel);
  border: 1px solid var(--c-line);
  border-radius: 999px;
  overflow: hidden;
}

.page-about .ab-bar__fill {
  display: block;
  height: 100%;
  background: var(--c-green);
  border-radius: 999px;
}

.page-about .ab-tags {
  list-style: none;
  margin: 28px 0 0;
  padding: 0;
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
}

.page-about .ab-tag {
  padding: 6px 12px;
  font-size: 12.5px;
  color: var(--c-silver);
  background: var(--c-panel);
  border: 1px solid var(--c-line);
  border-radius: 999px;
  transition: color 180ms var(--ease), border-color 180ms var(--ease), background 180ms var(--ease);
}

.page-about .ab-tag:hover {
  color: var(--c-white);
  border-color: var(--c-green);
  background: var(--c-hi);
}

/* ---------- 05 guangdong ---------- */

.page-about .ab-gd {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 28px;
}

.page-about .ab-gd__body p {
  margin: 0;
  max-width: 58ch;
  font-size: 15.5px;
  line-height: 1.85;
  color: var(--c-silver);
}

.page-about .ab-facts {
  list-style: none;
  margin: 22px 0 24px;
  padding: 0;
  border-top: 1px solid var(--c-line);
}

.page-about .ab-facts li {
  display: flex;
  flex-wrap: wrap;
  justify-content: space-between;
  align-items: baseline;
  gap: 8px 16px;
  padding: 12px 0;
  font-size: 14px;
  color: var(--c-grey);
  border-bottom: 1px solid var(--c-line);
}

.page-about .ab-facts li .mono {
  font-size: 15px;
  color: var(--c-white);
}

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

/* ---------- 06 trust ---------- */

.page-about .ab-trust {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 16px;
}

.page-about .ab-trust__card {
  padding: 26px 22px 28px;
  background: var(--c-panel);
  border: 1px solid var(--c-line);
  border-radius: var(--radius);
  box-shadow: var(--shadow);
}

.page-about .ab-trust__card h3 {
  margin: 0 0 12px;
  font-size: 19px;
  font-weight: 700;
  letter-spacing: -0.01em;
  color: var(--c-white);
}

.page-about .ab-trust__card > p {
  margin: 0 0 18px;
  font-size: 15px;
  line-height: 1.82;
  color: var(--c-silver);
}

.page-about .ab-trust__hint {
  font-size: 14px !important;
  color: var(--c-grey) !important;
}

.page-about .ab-steps {
  list-style: none;
  margin: 0;
  padding: 0;
  display: grid;
  gap: 10px;
}

.page-about .ab-steps li {
  display: flex;
  gap: 12px;
  align-items: baseline;
  font-size: 14px;
  line-height: 1.7;
  color: var(--c-grey);
}

.page-about .ab-steps .mono {
  flex: 0 0 auto;
  font-size: 12px;
  color: var(--c-green);
  letter-spacing: 0.06em;
}

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

@media (min-width: 620px) {
  .page-about .ab-exhibits {
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }

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

@media (min-width: 780px) {
  .page-about .ab-trust {
    grid-template-columns: repeat(2, minmax(0, 1fr));
    gap: 20px;
  }

  .page-about .ab-trust__card {
    padding: 28px 26px 30px;
  }
}

@media (min-width: 900px) {
  .page-about .ab-hero {
    padding: 40px 0 64px;
  }

  .page-about .ab-hero__grid {
    grid-template-columns: minmax(0, 8fr) minmax(0, 4fr);
    gap: 48px;
    align-items: end;
  }

  .page-about .ab-eco {
    grid-template-columns: minmax(0, 6fr) minmax(0, 6fr);
    gap: 44px;
  }

  .page-about .ab-gd {
    grid-template-columns: minmax(0, 7fr) minmax(0, 5fr);
    gap: 46px;
    align-items: start;
  }
}

@media (min-width: 1000px) {
  .page-about .ab-shell {
    grid-template-columns: var(--ab-rail) minmax(0, 1fr);
    gap: var(--ab-gap);
    align-items: start;
  }

  .page-about .ab-rail {
    position: sticky;
    top: 104px;
    align-self: start;
    padding: 66px 20px 0 0;
    border-right: 1px solid var(--c-line);
  }

  .page-about .ab-rail__list {
    flex-direction: column;
    gap: 2px;
    overflow: visible;
    padding-bottom: 0;
  }

  .page-about .ab-rail__link {
    border: 0;
    border-left: 2px solid var(--c-line);
    border-radius: 0;
    background: transparent;
    padding: 10px 10px;
    white-space: normal;
  }

  .page-about .ab-rail__link:hover,
  .page-about .ab-rail__link:focus-visible {
    border-left-color: var(--c-green);
    background: var(--c-hi);
  }

  .page-about .ab-stream {
    padding-top: 66px;
  }

  .page-about .ab-sec {
    padding-top: 52px;
  }
}

@media (min-width: 1160px) {
  .page-about .ab-exhibits {
    grid-template-columns: repeat(3, minmax(0, 1fr));
  }
}

@media (prefers-reduced-motion: reduce) {
  .page-about .ab-exhibit,
  .page-about .ab-tl::before,
  .page-about .ab-tl__ver,
  .page-about .ab-rail__link {
    transition: none;
  }

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