.page-about {
  --ab-gap: clamp(3.25rem, 8vw, 6.5rem);
  --ab-pad: clamp(1.15rem, 3.5vw, 1.75rem);
  --ab-radius: var(--r-xl);
  position: relative;
  color: var(--cream);
  background:
    radial-gradient(95% 50% at 88% 0%, rgba(18, 49, 42, 0.95), rgba(14, 18, 16, 0) 62%),
    radial-gradient(70% 40% at 0% 55%, rgba(226, 58, 46, 0.09), rgba(14, 18, 16, 0) 70%),
    var(--ink);
  padding-bottom: clamp(3rem, 8vw, 5.5rem);
  overflow-x: clip;
}

.page-about .ab-crumbs-wrap {
  padding-top: clamp(1rem, 3vw, 1.75rem);
}

.page-about .ab-block {
  margin-top: var(--ab-gap);
}

/* ---------- 首屏 ---------- */
.page-about .ab-hero {
  padding: clamp(1.75rem, 5vw, 2.75rem) 0 clamp(2.25rem, 6vw, 3.5rem);
  border-bottom: 1px solid var(--line-soft);
}

.page-about .ab-hero__inner {
  display: grid;
  gap: clamp(1.65rem, 5vw, 3rem);
  align-items: center;
}

.page-about .ab-kicker {
  margin: 0 0 0.9rem;
  font-family: var(--font-mono);
  font-size: 0.78rem;
  letter-spacing: 0.12em;
  text-transform: uppercase;
  color: var(--lime);
}

.page-about .ab-hero__title {
  margin: 0 0 1rem;
  font-size: clamp(2rem, 7.5vw, 3.6rem);
  font-weight: 800;
  line-height: 1.08;
  letter-spacing: -0.01em;
  color: var(--cream);
}

.page-about .ab-hero__text {
  margin: 0 0 1.6rem;
  max-width: 62ch;
  font-size: clamp(1rem, 2.4vw, 1.1rem);
  line-height: 1.8;
  color: var(--grey);
}

.page-about .ab-hero__facts {
  display: flex;
  flex-wrap: wrap;
  gap: 0.6rem 1.6rem;
  margin: 0;
  padding: 0;
  list-style: none;
}

.page-about .ab-hero__fact {
  display: flex;
  align-items: baseline;
  gap: 0.45rem;
  padding: 0.55rem 1.05rem;
  border: 1px solid var(--line);
  border-radius: var(--r-pill);
  background: rgba(243, 239, 230, 0.02);
}

.page-about .ab-hero__fact-num {
  font-family: var(--font-mono);
  font-size: 1.15rem;
  font-weight: 700;
  color: var(--red);
  letter-spacing: -0.02em;
}

.page-about .ab-hero__fact-label {
  font-size: 0.85rem;
  color: var(--cream);
}

.page-about .ab-hero__figure {
  margin: 0;
  border-radius: var(--ab-radius);
  border: 1px solid var(--line);
  overflow: hidden;
  background: var(--ink-green);
}

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

.page-about .ab-hero__figure .figure__cap {
  padding: 0.85rem var(--ab-pad);
  font-family: var(--font-mono);
  font-size: 0.76rem;
  letter-spacing: 0.06em;
  color: var(--grey);
  border-top: 1px solid var(--line-soft);
}

/* ---------- 章节头 ---------- */
.page-about .ab-sec {
  display: grid;
  grid-template-columns: max-content 1fr;
  column-gap: 0.9rem;
  row-gap: 0.45rem;
  align-items: baseline;
  margin-bottom: clamp(1.75rem, 4vw, 2.75rem);
}

.page-about .ab-sec::before {
  content: "";
  grid-column: 1 / -1;
  height: 2px;
  margin-bottom: 0.5rem;
  border-radius: var(--r-pill);
  background: linear-gradient(90deg, var(--red) 0%, var(--orange) 38%, var(--lime) 100%);
  opacity: 0.85;
}

.page-about .ab-sec__num {
  margin: 0;
  font-family: var(--font-mono);
  font-size: clamp(1.3rem, 4vw, 1.85rem);
  font-weight: 700;
  color: var(--red);
  letter-spacing: -0.02em;
}

.page-about .ab-sec__title {
  margin: 0;
  font-size: clamp(1.5rem, 5vw, 2.4rem);
  font-weight: 800;
  line-height: 1.18;
  color: var(--cream);
}

.page-about .ab-sec__sub {
  grid-column: 1 / -1;
  margin: 0;
  max-width: 66ch;
  font-size: clamp(0.97rem, 2.3vw, 1.05rem);
  line-height: 1.8;
  color: var(--grey);
}

/* ---------- 01 时间线 ---------- */
.page-about .ab-timeline {
  position: relative;
  margin: 0;
  padding: 0;
  list-style: none;
  display: grid;
  gap: clamp(2rem, 5vw, 3rem);
}

.page-about .ab-timeline::before {
  content: "";
  position: absolute;
  left: 6px;
  top: 8px;
  bottom: 8px;
  width: 2px;
  border-radius: var(--r-pill);
  background: linear-gradient(180deg, var(--red) 0%, var(--orange) 48%, var(--lime) 100%);
  opacity: 0.75;
}

.page-about .ab-stage {
  position: relative;
  padding-left: 2.1rem;
}

.page-about .ab-stage__dot {
  position: absolute;
  left: 0;
  top: 0.35rem;
  width: 14px;
  height: 14px;
  border-radius: 50%;
  background: var(--ink);
  border: 2px solid var(--red);
  box-shadow: 0 0 0 4px rgba(226, 58, 46, 0.12);
}

.page-about .ab-stage:nth-child(2) .ab-stage__dot {
  border-color: var(--orange);
  box-shadow: 0 0 0 4px rgba(242, 140, 40, 0.12);
}

.page-about .ab-stage:nth-child(3) .ab-stage__dot {
  border-color: var(--lime);
  box-shadow: 0 0 0 4px var(--lime-soft);
}

.page-about .ab-stage:nth-child(4) .ab-stage__dot {
  border-color: var(--white);
  box-shadow: 0 0 0 4px rgba(255, 255, 255, 0.1);
}

.page-about .ab-stage__tag {
  margin: 0 0 0.5rem;
  font-family: var(--font-mono);
  font-size: 0.74rem;
  letter-spacing: 0.1em;
  color: var(--lime);
}

.page-about .ab-stage__title {
  margin: 0 0 0.7rem;
  font-size: clamp(1.2rem, 3.6vw, 1.6rem);
  font-weight: 800;
  line-height: 1.3;
  color: var(--cream);
}

.page-about .ab-stage__text {
  margin: 0 0 0.9rem;
  max-width: 68ch;
  font-size: 1rem;
  line-height: 1.8;
  color: var(--grey);
}

.page-about .ab-stage__more {
  max-width: 68ch;
}

.page-about .ab-stage__more .disclosure__btn {
  display: inline-flex;
  align-items: center;
  gap: 0.5rem;
  padding: 0.5rem 1.05rem;
  border: 1px solid var(--line);
  border-radius: var(--r-pill);
  background: transparent;
  color: var(--cream);
  font-family: var(--font-mono);
  font-size: 0.78rem;
  letter-spacing: 0.06em;
  cursor: pointer;
  transition: border-color 0.24s var(--ease), color 0.24s var(--ease), background 0.24s var(--ease);
}

.page-about .ab-stage__more .disclosure__btn::after {
  content: "+";
  font-size: 1rem;
  line-height: 1;
  color: var(--lime);
}

.page-about .ab-stage__more .disclosure__btn[aria-expanded="true"]::after {
  content: "−";
}

.page-about .ab-stage__more .disclosure__btn:hover {
  border-color: var(--lime);
  color: var(--white);
  background: var(--lime-soft);
}

.page-about .ab-bullets {
  margin: 1rem 0 0;
  padding: 0 0 0 1.1rem;
  display: grid;
  gap: 0.6rem;
  list-style: none;
}

.page-about .ab-bullets li {
  position: relative;
  font-size: 0.95rem;
  line-height: 1.75;
  color: var(--grey);
}

.page-about .ab-bullets li::before {
  content: "";
  position: absolute;
  left: -1.1rem;
  top: 0.68rem;
  width: 6px;
  height: 6px;
  border-radius: 50%;
  background: var(--lime);
}

/* ---------- 02 覆盖 ---------- */
.page-about .ab-coverage {
  position: relative;
  border-radius: var(--ab-radius);
  border: 1px solid var(--line);
  background: var(--ink-green);
  padding: clamp(1.25rem, 4vw, 2.5rem);
  display: grid;
  gap: clamp(1.5rem, 4vw, 2.5rem);
  overflow: hidden;
}

.page-about .ab-coverage__bg {
  position: absolute;
  inset: 0;
  width: 100%;
  height: 100%;
  object-fit: cover;
  opacity: 0.16;
  filter: grayscale(1) contrast(1.1);
  pointer-events: none;
}

.page-about .ab-coverage__map,
.page-about .ab-coverage__list {
  position: relative;
}

.page-about .ab-map {
  display: block;
  width: 100%;
  max-width: 100%;
  height: auto;
}

.page-about .ab-map__shape {
  fill: none;
  stroke: rgba(198, 242, 78, 0.28);
  stroke-width: 1.4;
  stroke-dasharray: 6 8;
  stroke-linejoin: round;
}

.page-about .ab-city circle {
  fill: var(--lime);
  transition: fill 0.24s var(--ease);
}

.page-about .ab-city text {
  fill: var(--grey);
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.04em;
  transition: fill 0.24s var(--ease);
}

.page-about .ab-city:hover circle {
  fill: var(--red);
}

.page-about .ab-city:hover text {
  fill: var(--white);
}

.page-about .ab-coverage__hint {
  margin: 0.9rem 0 0;
  font-family: var(--font-mono);
  font-size: 0.74rem;
  letter-spacing: 0.05em;
  color: var(--grey);
}

.page-about .ab-coverage__list {
  margin: 0;
  display: grid;
  gap: 0.75rem;
}

.page-about .ab-coverage__row {
  padding: 0.85rem 1.05rem;
  border-radius: var(--r-md);
  border: 1px solid var(--line-soft);
  background: rgba(14, 18, 16, 0.42);
  transition: border-color 0.24s var(--ease), transform 0.24s var(--ease);
}

.page-about .ab-coverage__row:hover {
  border-color: var(--lime);
  transform: translateY(-2px);
}

.page-about .ab-coverage__row dt {
  font-family: var(--font-mono);
  font-size: 0.72rem;
  letter-spacing: 0.1em;
  color: var(--lime);
  margin-bottom: 0.35rem;
}

.page-about .ab-coverage__row dd {
  margin: 0;
  font-size: 0.97rem;
  line-height: 1.65;
  color: var(--cream);
}

/* ---------- 03 团队 ---------- */
.page-about .ab-team {
  position: relative;
  margin-bottom: clamp(1.75rem, 4vw, 2.75rem);
}

.page-about .ab-team__root {
  display: inline-block;
  margin: 0 0 1.5rem;
  padding: 0.55rem 1.15rem;
  border-radius: var(--r-pill);
  background: var(--red);
  color: var(--white);
  font-size: 0.92rem;
  font-weight: 700;
}

.page-about .ab-roles {
  position: relative;
  margin: 0;
  padding: 0 0 0 1.4rem;
  list-style: none;
  display: grid;
  gap: 1rem;
}

.page-about .ab-roles::before {
  content: "";
  position: absolute;
  left: 5px;
  top: 0.6rem;
  bottom: 0.6rem;
  width: 2px;
  background: linear-gradient(180deg, var(--red), var(--lime));
  opacity: 0.55;
  border-radius: var(--r-pill);
}

.page-about .ab-role {
  position: relative;
  padding: var(--ab-pad);
  border-radius: var(--r-lg);
  border: 1px solid var(--line);
  background: rgba(243, 239, 230, 0.025);
  transition: border-color 0.24s var(--ease), background 0.24s var(--ease);
}

.page-about .ab-role:hover {
  border-color: var(--lime);
  background: var(--lime-soft);
}

.page-about .ab-role__node {
  position: absolute;
  left: -1.4rem;
  top: 1.6rem;
  width: 10px;
  height: 10px;
  border-radius: 50%;
  background: var(--lime);
  transform: translateX(1px);
}

.page-about .ab-role:hover .ab-role__node {
  background: var(--red);
}

.page-about .ab-role__name {
  margin: 0 0 0.5rem;
  font-size: 1.12rem;
  font-weight: 800;
  color: var(--cream);
}

.page-about .ab-role__desc {
  margin: 0;
  font-size: 0.96rem;
  line-height: 1.75;
  color: var(--grey);
}

.page-about .ab-team__figure {
  margin: 0;
  border-radius: var(--ab-radius);
  overflow: hidden;
  border: 1px solid var(--line);
  background: var(--ink-green);
}

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

.page-about .ab-team__figure .figure__cap {
  padding: 0.85rem var(--ab-pad);
  font-family: var(--font-mono);
  font-size: 0.76rem;
  letter-spacing: 0.05em;
  color: var(--grey);
  border-top: 1px solid var(--line-soft);
}

/* ---------- 04 合作 ---------- */
.page-about .ab-partners {
  margin-bottom: clamp(1.5rem, 4vw, 2.25rem);
}

.page-about .ab-partner {
  padding: var(--ab-pad);
  border-radius: var(--r-lg);
  border: 1px solid var(--line);
  background: rgba(243, 239, 230, 0.025);
  display: grid;
  gap: 0.6rem;
  align-content: start;
  transition: border-color 0.24s var(--ease), transform 0.24s var(--ease);
}

.page-about .ab-partner:hover {
  border-color: var(--lime);
  transform: translateY(-3px);
}

.page-about .ab-partner__tag {
  margin: 0;
  justify-self: start;
}

.page-about .ab-partner__name {
  margin: 0;
  font-size: 1.14rem;
  font-weight: 800;
  color: var(--cream);
}

.page-about .ab-partner__desc {
  margin: 0;
  font-size: 0.95rem;
  line-height: 1.75;
  color: var(--grey);
}

.page-about .ab-discipline {
  position: relative;
  padding: clamp(1.25rem, 4vw, 2rem) clamp(1.25rem, 4vw, 2.25rem);
  border-radius: var(--ab-radius);
  border-left: 4px solid var(--orange);
  background: linear-gradient(100deg, rgba(242, 140, 40, 0.1), rgba(18, 49, 42, 0.35));
}

.page-about .ab-discipline__title {
  margin: 0 0 0.7rem;
  font-size: clamp(1.1rem, 3.2vw, 1.35rem);
  font-weight: 800;
  color: var(--cream);
}

.page-about .ab-discipline__text {
  margin: 0;
  max-width: 70ch;
  font-size: 0.98rem;
  line-height: 1.85;
  color: var(--grey);
}

/* ---------- 05 里程碑 ---------- */
.page-about .ab-milestones {
  margin: 0;
  padding: 0;
  list-style: none;
  display: flex;
  flex-wrap: wrap;
  gap: 0.7rem;
}

.page-about .ab-milestone {
  display: inline-flex;
  align-items: center;
  gap: 0.7rem;
  padding: 0.6rem 1.15rem 0.6rem 0.75rem;
  border-radius: var(--r-pill);
  border: 1px solid var(--line);
  background: rgba(243, 239, 230, 0.03);
  transition: border-color 0.24s var(--ease), background 0.24s var(--ease);
}

.page-about .ab-milestone:hover {
  border-color: var(--lime);
  background: var(--lime-soft);
}

.page-about .ab-milestone__ver {
  padding: 0.2rem 0.6rem;
  border-radius: var(--r-pill);
  background: var(--red);
  color: var(--white);
  font-family: var(--font-mono);
  font-size: 0.74rem;
  font-weight: 700;
  letter-spacing: 0.05em;
}

.page-about .ab-milestone__label {
  font-size: 0.92rem;
  color: var(--cream);
}

.page-about .ab-milestones__note {
  margin: 1.4rem 0 0;
  max-width: 66ch;
  font-family: var(--font-mono);
  font-size: 0.78rem;
  line-height: 1.7;
  letter-spacing: 0.03em;
  color: var(--grey);
}

/* ---------- 收尾 ---------- */
.page-about .ab-cta {
  margin-top: var(--ab-gap);
}

.page-about .ab-cta__inner {
  position: relative;
  border-radius: var(--ab-radius);
  padding: clamp(1.75rem, 5vw, 3rem);
  background:
    radial-gradient(120% 100% at 100% 0%, rgba(198, 242, 78, 0.16), rgba(14, 18, 16, 0) 60%),
    var(--ink-deep);
  border: 1px solid var(--line);
}

.page-about .ab-cta__title {
  margin: 0 0 0.85rem;
  font-size: clamp(1.4rem, 4.5vw, 2.1rem);
  font-weight: 800;
  line-height: 1.2;
  color: var(--cream);
}

.page-about .ab-cta__text {
  margin: 0 0 1.6rem;
  max-width: 64ch;
  font-size: 1rem;
  line-height: 1.8;
  color: var(--grey);
}

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

/* ---------- 响应式 ---------- */
@media (min-width: 720px) {
  .page-about .ab-roles {
    grid-template-columns: repeat(2, minmax(0, 1fr));
    gap: 1.15rem 1.4rem;
  }

  .page-about .ab-stage {
    padding-left: 2.6rem;
  }

  .page-about .ab-timeline::before {
    left: 8px;
  }

  .page-about .ab-stage__dot {
    left: 2px;
  }
}

@media (min-width: 900px) {
  .page-about .ab-hero__inner {
    grid-template-columns: 1.05fr 0.95fr;
  }

  .page-about .ab-coverage {
    grid-template-columns: minmax(0, 1.25fr) minmax(0, 1fr);
    align-items: start;
  }

  .page-about .ab-team__figure {
    max-width: 760px;
  }
}

@media (min-width: 1080px) {
  .page-about .ab-hero__inner {
    grid-template-columns: 1.1fr 0.9fr;
    gap: 3.5rem;
  }

  .page-about .ab-roles {
    grid-template-columns: repeat(4, minmax(0, 1fr));
    padding-left: 0;
    gap: 1.25rem;
  }

  .page-about .ab-roles::before {
    left: 0;
    right: 0;
    top: 0;
    bottom: auto;
    width: auto;
    height: 2px;
    background: linear-gradient(90deg, var(--red), var(--orange) 50%, var(--lime));
  }

  .page-about .ab-role {
    padding-top: calc(var(--ab-pad) + 0.75rem);
  }

  .page-about .ab-role__node {
    left: 0;
    top: -5px;
    width: 12px;
    height: 12px;
  }
}