.page-about {
  --ab-block: clamp(52px, 7vw, 96px);
  --ab-soft: rgba(76, 123, 255, 0.07);
  background: var(--white);
  color: var(--graphite);
}

/* ---------- 首屏 ---------- */
.page-about .ab-hero {
  position: relative;
  overflow: hidden;
  background: linear-gradient(148deg, var(--navy) 0%, #0a2358 52%, var(--blue) 100%);
  color: var(--white);
  padding: clamp(24px, 4vw, 40px) 0 calc(var(--seam) + clamp(56px, 8vw, 96px));
}

.page-about .ab-hero::before {
  content: "";
  position: absolute;
  left: -5%;
  right: -5%;
  bottom: -1px;
  height: var(--seam);
  background: var(--white);
  transform: skewY(-1.6deg);
  transform-origin: right bottom;
}

.page-about .ab-hero::after {
  content: "";
  position: absolute;
  left: -5%;
  right: -5%;
  bottom: calc(var(--seam) - 3px);
  height: 2px;
  background: var(--orange);
  transform: skewY(-1.6deg);
  transform-origin: right bottom;
}

.page-about .ab-hero .breadcrumbs__link,
.page-about .ab-hero .breadcrumbs__item,
.page-about .ab-hero .breadcrumbs__sep {
  color: rgba(255, 255, 255, 0.7);
  font-size: 13px;
}

.page-about .ab-hero .breadcrumbs__link {
  text-decoration: none;
  border-bottom: 1px solid transparent;
  transition: border-color 0.2s ease, color 0.2s ease;
}

.page-about .ab-hero .breadcrumbs__link:hover {
  color: var(--white);
  border-bottom-color: var(--orange);
}

.page-about .ab-hero__eyebrow {
  margin: clamp(20px, 3vw, 32px) 0 0;
  color: var(--pulse);
  font-family: var(--font-narrow);
  letter-spacing: 0.18em;
  text-transform: uppercase;
  font-size: 12px;
}

.page-about .ab-hero__grid {
  display: grid;
  gap: clamp(18px, 3vw, 40px);
  margin-top: clamp(12px, 2vw, 18px);
}

.page-about .ab-hero__title {
  margin: 0;
  font-size: clamp(28px, 5.2vw, 50px);
  line-height: 1.14;
  letter-spacing: -0.01em;
  font-weight: 800;
  max-width: 22em;
}

.page-about .ab-hero__lead p {
  margin: 0 0 14px;
  font-size: clamp(15px, 1.6vw, 17px);
  line-height: 1.75;
  color: rgba(255, 255, 255, 0.88);
}

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

.page-about .ab-hero__en {
  font-family: var(--font-body);
  font-size: 13.5px;
  line-height: 1.7;
  color: rgba(255, 255, 255, 0.66);
  text-transform: none;
  letter-spacing: 0;
  border-left: 2px solid rgba(255, 255, 255, 0.22);
  padding-left: 14px;
}

.page-about .ab-hero__stats {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 18px 14px;
  margin: clamp(28px, 4vw, 46px) 0 0;
  padding: 22px 0 0;
  border-top: 1px solid rgba(255, 255, 255, 0.2);
}

.page-about .ab-hero__stat dt {
  margin: 0 0 6px;
  font-size: 12px;
  letter-spacing: 0.08em;
  color: rgba(255, 255, 255, 0.62);
}

.page-about .ab-hero__stat dd {
  margin: 0;
  font-size: clamp(17px, 2vw, 21px);
  font-weight: 700;
  color: var(--white);
}

.page-about .ab-hero__stat dd .num {
  font-family: var(--font-mono);
  font-size: clamp(24px, 3.2vw, 32px);
  font-weight: 600;
  color: var(--white);
  margin-right: 4px;
}

/* ---------- 通用区块 ---------- */
.page-about .ab-section {
  padding: var(--ab-block) 0;
}

.page-about .ab-section--ice {
  background: var(--ice);
}

.page-about .ab-section--shell {
  background: var(--shell);
}

.page-about .ab-section .section-head__zh {
  margin: 6px 0 0;
  font-size: clamp(22px, 3vw, 32px);
  line-height: 1.3;
  letter-spacing: -0.01em;
  font-weight: 800;
}

.page-about .ab-section .section-head__en {
  margin: 6px 0 0;
  font-family: var(--font-narrow);
  font-size: 12px;
  letter-spacing: 0.16em;
  text-transform: uppercase;
  color: var(--gray);
}

.page-about .ab-section .eyebrow {
  margin: 0;
  font-family: var(--font-narrow);
  font-size: 11px;
  letter-spacing: 0.2em;
  text-transform: uppercase;
  color: var(--blue);
}

.page-about .ab-section .section-head {
  margin-bottom: clamp(24px, 3.4vw, 40px);
}

/* ---------- 双语对照板 ---------- */
.page-about .ab-board {
  border-top: 1px solid var(--line);
}

.page-about .ab-board__row {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 8px 32px;
  padding: 22px 12px 22px 0;
  border-bottom: 1px solid var(--line);
  transition: background-color 0.24s ease;
}

.page-about .ab-board__row:hover {
  background: var(--ab-soft);
}

.page-about .ab-board__zh {
  margin: 0;
  font-size: 15.5px;
  line-height: 1.78;
  color: var(--graphite);
}

.page-about .ab-board__en {
  margin: 0;
  font-family: var(--font-body);
  font-size: 13.5px;
  line-height: 1.78;
  color: var(--gray);
  text-transform: none;
  letter-spacing: 0;
  padding-left: 14px;
  border-left: 1px solid var(--line);
}

.page-about .ab-board a {
  color: var(--blue);
  text-decoration: none;
  border-bottom: 1px solid rgba(27, 79, 216, 0.32);
}

.page-about .ab-board a:hover {
  color: var(--navy);
  border-bottom-color: var(--orange);
}

/* ---------- 成稿流程 ---------- */
.page-about .ab-flow__figure {
  margin: 0 0 clamp(24px, 3.6vw, 40px);
}

.page-about .ab-flow__figure img {
  display: block;
  width: 100%;
  max-width: 100%;
  height: auto;
  object-fit: cover;
  border: 1px solid var(--line);
  background: var(--white);
}

.page-about .ab-flow__caption {
  margin-top: 10px;
  font-size: 12.5px;
  line-height: 1.7;
  color: var(--gray);
}

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

.page-about .ab-step {
  position: relative;
  padding: 20px 16px 24px 20px;
  border-bottom: 1px solid var(--line);
}

.page-about .ab-step__num {
  display: inline-block;
  font-family: var(--font-mono);
  font-size: 12px;
  font-weight: 600;
  letter-spacing: 0.08em;
  color: var(--white);
  background: var(--navy);
  padding: 3px 8px;
  clip-path: polygon(0 0, 100% 0, 100% 74%, 78% 100%, 0 100%);
}

.page-about .ab-step__title {
  margin: 12px 0 8px;
  font-size: 17px;
  font-weight: 700;
  line-height: 1.4;
  color: var(--navy);
}

.page-about .ab-step__zh {
  margin: 0 0 10px;
  font-size: 14.5px;
  line-height: 1.75;
  color: var(--graphite);
}

.page-about .ab-step__en {
  margin: 0;
  font-family: var(--font-body);
  font-size: 13px;
  line-height: 1.72;
  color: var(--gray);
  text-transform: none;
  letter-spacing: 0;
}

/* ---------- 赛后复核 ---------- */
.page-about .ab-review {
  display: grid;
  gap: clamp(22px, 3vw, 36px);
  border-top: 3px solid var(--navy);
  padding-top: clamp(22px, 3vw, 32px);
}

.page-about .ab-review__title {
  margin: 6px 0 0;
  font-size: clamp(22px, 3vw, 32px);
  line-height: 1.3;
  letter-spacing: -0.01em;
  font-weight: 800;
  color: var(--graphite);
}

.page-about .ab-review .eyebrow {
  margin: 0;
  font-family: var(--font-narrow);
  font-size: 11px;
  letter-spacing: 0.2em;
  text-transform: uppercase;
  color: var(--green);
}

.page-about .ab-review__en {
  margin: 6px 0 0;
  font-family: var(--font-narrow);
  font-size: 12px;
  letter-spacing: 0.16em;
  text-transform: uppercase;
  color: var(--gray);
}

.page-about .ab-review__body {
  display: grid;
  gap: 0;
}

.page-about .ab-review__col {
  padding: 0 0 0 18px;
  border-left: 2px solid var(--line);
}

.page-about .ab-review__col p {
  margin: 0 0 16px;
  font-size: 15px;
  line-height: 1.78;
  color: var(--graphite);
}

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

.page-about .ab-review__col--en p {
  font-family: var(--font-body);
  font-size: 13.5px;
  line-height: 1.78;
  color: var(--gray);
  text-transform: none;
  letter-spacing: 0;
}

.page-about .ab-review__col--en {
  margin-top: 20px;
  border-left-color: var(--green);
}

/* ---------- 竖向时间线 ---------- */
.page-about .ab-timeline {
  display: grid;
  gap: clamp(24px, 3.4vw, 44px);
}

.page-about .ab-timeline__visual img {
  display: block;
  width: 100%;
  max-width: 100%;
  height: auto;
  object-fit: cover;
  border: 1px solid var(--line);
  background: var(--white);
}

.page-about .ab-timeline__list {
  position: relative;
  list-style: none;
  margin: 0;
  padding: 0 0 0 22px;
  border-left: 1px solid var(--line);
}

.page-about .ab-timeline__item {
  position: relative;
  padding-bottom: 6px;
}

.page-about .ab-timeline__item::before {
  content: "";
  position: absolute;
  left: -27px;
  top: 20px;
  width: 10px;
  height: 10px;
  background: var(--blue);
  clip-path: polygon(0 0, 100% 0, 100% 70%, 68% 100%, 0 100%);
}

.page-about .ab-timeline__item:last-child::before {
  background: var(--orange);
}

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

.page-about .ab-node__summary {
  display: grid;
  gap: 2px;
  padding: 12px 30px 12px 0;
  cursor: pointer;
  list-style: none;
  position: relative;
}

.page-about .ab-node__summary::-webkit-details-marker {
  display: none;
}

.page-about .ab-node__summary::after {
  content: "+";
  position: absolute;
  right: 2px;
  top: 12px;
  font-family: var(--font-mono);
  font-size: 15px;
  line-height: 1;
  color: var(--blue);
}

.page-about .ab-node[open] .ab-node__summary::after {
  content: "–";
  color: var(--orange);
}

.page-about .ab-node__stage {
  font-family: var(--font-narrow);
  font-size: 11px;
  letter-spacing: 0.16em;
  text-transform: uppercase;
  color: var(--gray);
}

.page-about .ab-node__title {
  font-size: 16px;
  font-weight: 700;
  line-height: 1.45;
  color: var(--navy);
}

.page-about .ab-node__body {
  padding: 2px 0 18px;
}

.page-about .ab-node__body p {
  margin: 0 0 10px;
  font-size: 14px;
  line-height: 1.76;
  color: var(--graphite);
}

.page-about .ab-node__body p.u-en {
  margin: 0;
  font-family: var(--font-body);
  font-size: 13px;
  line-height: 1.72;
  color: var(--gray);
  text-transform: none;
  letter-spacing: 0;
  padding-left: 12px;
  border-left: 1px solid var(--line);
}

/* ---------- 团队 ---------- */
.page-about .ab-team__figure {
  margin: 0 0 clamp(20px, 3vw, 32px);
}

.page-about .ab-team__figure img {
  display: block;
  width: 100%;
  max-width: 100%;
  height: auto;
  object-fit: cover;
  border: 1px solid var(--line);
}

.page-about .ab-team {
  display: grid;
  gap: 1px;
  background: var(--line);
  border: 1px solid var(--line);
}

.page-about .ab-team__col {
  background: var(--white);
  padding: 22px 20px 26px;
}

.page-about .ab-team__col:nth-child(1) {
  background: var(--ice);
}

.page-about .ab-team__col:nth-child(2) {
  background: var(--shell);
}

.page-about .ab-team__col:nth-child(3) {
  background: var(--navy);
  color: var(--white);
}

.page-about .ab-team__tag {
  margin: 0 0 10px;
  font-family: var(--font-narrow);
  font-size: 11px;
  letter-spacing: 0.18em;
  text-transform: uppercase;
  color: var(--blue);
}

.page-about .ab-team__col:nth-child(3) .ab-team__tag {
  color: var(--orange);
}

.page-about .ab-team__name {
  margin: 0 0 10px;
  font-size: 18px;
  font-weight: 700;
  line-height: 1.4;
  color: var(--navy);
}

.page-about .ab-team__col:nth-child(3) .ab-team__name {
  color: var(--white);
}

.page-about .ab-team__text {
  margin: 0 0 12px;
  font-size: 14px;
  line-height: 1.76;
  color: var(--graphite);
}

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

.page-about .ab-team__col:nth-child(3) .ab-team__text {
  color: rgba(255, 255, 255, 0.82);
}

.page-about .ab-team__text.u-en {
  font-family: var(--font-body);
  font-size: 12.5px;
  line-height: 1.7;
  color: var(--gray);
  text-transform: none;
  letter-spacing: 0;
}

.page-about .ab-team__col:nth-child(3) .ab-team__text.u-en {
  color: rgba(255, 255, 255, 0.62);
}

.page-about .ab-team__rhythm {
  display: grid;
  gap: 12px;
  margin-top: clamp(20px, 3vw, 30px);
  padding: 20px 20px 22px;
  background: var(--ice);
  border-left: 3px solid var(--orange);
}

.page-about .ab-team__rhythm-zh {
  margin: 0;
  font-size: 14.5px;
  line-height: 1.76;
  color: var(--graphite);
}

.page-about .ab-team__rhythm-en {
  margin: 0;
  font-family: var(--font-body);
  font-size: 13px;
  line-height: 1.72;
  color: var(--gray);
  text-transform: none;
  letter-spacing: 0;
}

/* ---------- 四条标准 ---------- */
.page-about .ab-standards {
  list-style: none;
  margin: 0;
  padding: 0;
}

.page-about .ab-standards__item {
  display: grid;
  grid-template-columns: 34px minmax(0, 1fr);
  gap: 0 14px;
  padding: 18px 0 20px 14px;
  border-left: 2px solid var(--line);
  border-bottom: 1px solid var(--line);
  transition: border-left-color 0.2s ease, background-color 0.24s ease;
}

.page-about .ab-standards__item:hover {
  border-left-color: var(--orange);
  background: rgba(255, 255, 255, 0.72);
}

.page-about .ab-standards__no {
  font-family: var(--font-mono);
  font-size: 13px;
  font-weight: 600;
  line-height: 1.9;
  color: var(--blue);
}

.page-about .ab-standards__title {
  margin: 0 0 6px;
  font-size: 15.5px;
  font-weight: 700;
  line-height: 1.45;
  color: var(--navy);
}

.page-about .ab-standards__content p {
  margin: 0 0 8px;
  font-size: 13.5px;
  line-height: 1.76;
  color: var(--graphite);
}

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

.page-about .ab-standards__content p.u-en {
  font-family: var(--font-body);
  font-size: 12.5px;
  line-height: 1.72;
  color: var(--gray);
  text-transform: none;
  letter-spacing: 0;
}

.page-about .ab-standards__content a {
  color: var(--blue);
  text-decoration: none;
  border-bottom: 1px solid rgba(27, 79, 216, 0.3);
}

.page-about .ab-standards__content a:hover {
  color: var(--navy);
  border-bottom-color: var(--orange);
}

/* ---------- 收尾 ---------- */
.page-about .ab-cta {
  padding: clamp(44px, 6vw, 80px) 0;
  background: var(--navy);
  color: var(--white);
}

.page-about .ab-cta__inner {
  display: grid;
  gap: clamp(22px, 3vw, 36px);
  align-items: center;
}

.page-about .ab-cta__title {
  margin: 0 0 12px;
  font-size: clamp(21px, 2.8vw, 30px);
  line-height: 1.32;
  letter-spacing: -0.01em;
  font-weight: 800;
  color: var(--white);
}

.page-about .ab-cta__desc {
  margin: 0 0 10px;
  font-size: 14.5px;
  line-height: 1.76;
  color: rgba(255, 255, 255, 0.84);
}

.page-about .ab-cta__desc.u-en {
  margin: 0;
  font-family: var(--font-body);
  font-size: 13px;
  line-height: 1.72;
  color: rgba(255, 255, 255, 0.6);
  text-transform: none;
  letter-spacing: 0;
}

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

.page-about .ab-cta__actions .btn--ghost {
  border-color: rgba(255, 255, 255, 0.45);
  color: var(--white);
}

.page-about .ab-cta__actions .btn--ghost:hover {
  border-color: var(--orange);
  color: var(--white);
}

/* ---------- 响应式 ---------- */
@media (min-width: 720px) {
  .page-about .ab-hero__stats {
    grid-template-columns: repeat(4, minmax(0, 1fr));
    gap: 18px 18px;
  }

  .page-about .ab-hero__stat {
    padding-left: 16px;
    border-left: 1px solid rgba(255, 255, 255, 0.16);
  }

  .page-about .ab-hero__stat:first-child {
    padding-left: 0;
    border-left: 0;
  }

  .page-about .ab-standards__item {
    grid-template-columns: 44px minmax(0, 1fr);
    gap: 0 20px;
  }
}

@media (min-width: 880px) {
  .page-about .ab-hero__grid {
    grid-template-columns: 5fr 7fr;
    align-items: start;
    gap: clamp(28px, 4vw, 60px);
  }

  .page-about .ab-hero__title {
    margin-top: 4px;
  }

  .page-about .ab-board__row {
    grid-template-columns: minmax(0, 1fr) minmax(0, 1fr);
    align-items: start;
    padding: 26px 16px 26px 0;
  }

  .page-about .ab-review {
    grid-template-columns: minmax(0, 4fr) minmax(0, 8fr);
    gap: clamp(24px, 3.4vw, 48px);
  }

  .page-about .ab-review__head {
    position: sticky;
    top: 120px;
    align-self: start;
  }

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

  .page-about .ab-review__col--en {
    margin-top: 0;
  }
}

@media (min-width: 900px) {
  .page-about .ab-steps {
    grid-template-columns: repeat(3, minmax(0, 1fr));
    border-left: 0;
    border-top: 1px solid var(--line);
  }

  .page-about .ab-step {
    border-bottom: 0;
    border-right: 1px solid var(--line);
    padding: 24px 22px 26px 0;
  }

  .page-about .ab-step:last-child {
    border-right: 0;
    padding-right: 0;
  }

  .page-about .ab-step + .ab-step {
    padding-left: 22px;
  }
}

@media (min-width: 960px) {
  .page-about .ab-timeline {
    grid-template-columns: minmax(0, 4fr) minmax(0, 8fr);
    align-items: start;
    gap: clamp(28px, 4vw, 56px);
  }

  .page-about .ab-timeline__visual {
    position: sticky;
    top: 120px;
  }

  .page-about .ab-node {
    padding-left: 18px;
  }

  .page-about .ab-timeline__item:nth-child(even) .ab-node {
    padding-left: 42px;
  }

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

  .page-about .ab-team__col {
    padding: 26px 24px 30px;
  }

  .page-about .ab-cta__inner {
    grid-template-columns: minmax(0, 8fr) minmax(0, 4fr);
  }

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

@media (prefers-reduced-motion: reduce) {
  .page-about .ab-board__row,
  .page-about .ab-standards__item,
  .page-about .ab-hero .breadcrumbs__link {
    transition: none;
  }
}