.page-about {
  position: relative;
  color: var(--ink-900);
  background-color: var(--paper-50);
}

.page-about::before {
  content: "";
  position: absolute;
  inset: 0;
  background-image:
    linear-gradient(to right, var(--grid-300) 1px, transparent 1px),
    linear-gradient(to bottom, var(--grid-300) 1px, transparent 1px);
  background-size: 96px 96px;
  opacity: 0.45;
  pointer-events: none;
}

.page-about > * {
  position: relative;
  z-index: 1;
}

.page-about .ab-wrap {
  padding: 22px 18px 64px;
}

/* ---------- 首屏 ---------- */

.page-about .ab-hero {
  padding-bottom: 34px;
}

.page-about .ab-hero__eyebrow {
  margin: 20px 0 12px;
  font-size: 12px;
  letter-spacing: 0.14em;
  color: var(--ice-deep);
  font-weight: 700;
}

.page-about .ab-hero__title {
  margin: 0 0 18px;
  max-width: 17em;
  font-size: clamp(1.95rem, 6.2vw, 3.4rem);
  font-weight: 900;
  line-height: 1.16;
  letter-spacing: -0.02em;
}

.page-about .ab-hero__lead {
  margin: 0;
  max-width: 64ch;
  font-size: 1.0625rem;
  line-height: 1.8;
  color: var(--ink-700);
}

.page-about .ab-facts {
  list-style: none;
  margin: 26px 0 0;
  padding: 0;
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 1px;
  background-color: var(--grid-300);
  border: 2px solid var(--ink-900);
}

.page-about .ab-facts__item {
  background-color: var(--paper-50);
  padding: 14px 14px 16px;
  display: flex;
  flex-direction: column;
  gap: 5px;
  min-width: 0;
}

.page-about .ab-facts__num {
  font-size: 1.7rem;
  font-weight: 700;
  line-height: 1.05;
  letter-spacing: -0.01em;
}

.page-about .ab-facts__unit {
  font-size: 0.78rem;
  font-weight: 400;
  margin-left: 3px;
  color: var(--ink-700);
}

.page-about .ab-facts__label {
  font-size: 0.8125rem;
  line-height: 1.55;
  color: var(--ink-700);
}

/* ---------- 章节骨架 ---------- */

.page-about .ab-sec {
  margin-top: 40px;
  padding-top: 34px;
  border-top: 1px solid var(--grid-300);
}

.page-about .sec-head {
  margin-bottom: 22px;
}

.page-about .sec-head__num {
  display: inline-block;
  padding: 2px 8px;
  background-color: var(--sprint-orange);
  color: var(--ink-900);
  font-size: 0.8125rem;
  font-weight: 700;
  letter-spacing: 0.06em;
}

.page-about .sec-head__meta {
  margin: 8px 0 0;
  font-size: 0.875rem;
  line-height: 1.65;
  color: var(--ink-700);
}

/* ---------- 01 三类人 ---------- */

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

.page-about .ab-aud__card {
  display: flex;
  flex-direction: column;
  gap: 10px;
  padding: 20px 18px;
  background-color: var(--paper-200);
  border: 2px solid var(--ink-900);
  box-shadow: var(--shadow-hard);
  transition: transform 100ms var(--ease), box-shadow 100ms var(--ease);
  min-width: 0;
}

.page-about .ab-aud__card:hover {
  transform: translate(-3px, -3px);
  box-shadow: var(--shadow-hard-lg);
}

.page-about .ab-aud__idx {
  font-size: 0.6875rem;
  font-weight: 700;
  letter-spacing: 0.14em;
  color: var(--green-deep);
}

.page-about .ab-aud__title {
  margin: 0;
  font-size: 1.125rem;
  font-weight: 800;
  line-height: 1.42;
}

.page-about .ab-aud__text {
  margin: 0;
  flex: 1;
  font-size: 0.9375rem;
  line-height: 1.74;
  color: var(--ink-700);
}

.page-about .ab-aud__link {
  align-self: flex-start;
  font-size: 0.875rem;
  font-weight: 700;
  color: var(--ice-deep);
  text-decoration: none;
  border-bottom: 2px solid var(--ice-deep);
  padding-bottom: 2px;
}

.page-about .ab-aud__link:hover {
  color: var(--green-deep);
  border-bottom-color: var(--green-deep);
}

/* ---------- 02 时间线 ---------- */

.page-about .ab-years {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
  margin: 0 0 26px;
}

.page-about .ab-years__link {
  display: inline-block;
  padding: 5px 12px;
  font-size: 0.8125rem;
  font-weight: 700;
  letter-spacing: 0.06em;
  color: var(--ink-900);
  background-color: var(--paper-50);
  border: 2px solid var(--ink-900);
  box-shadow: 2px 2px 0 var(--ink-900);
  text-decoration: none;
  transition: background-color 100ms var(--ease), box-shadow 100ms var(--ease);
}

.page-about .ab-years__link:hover {
  background-color: var(--green-tint);
  box-shadow: 3px 3px 0 var(--green-deep);
}

.page-about .ab-tl {
  position: relative;
  list-style: none;
  margin: 0;
  padding: 4px 0 0 28px;
}

.page-about .ab-tl::before {
  content: "";
  position: absolute;
  left: 0;
  top: 10px;
  bottom: 10px;
  width: 2px;
  background-color: var(--ink-900);
}

.page-about .ab-tl__item {
  position: relative;
  padding-bottom: 32px;
  scroll-margin-top: 24px;
  min-width: 0;
}

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

.page-about .ab-tl__item::before {
  content: "";
  position: absolute;
  left: -35px;
  top: 12px;
  width: 16px;
  height: 16px;
  box-sizing: border-box;
  background-color: var(--sprint-orange);
  border: 2px solid var(--ink-900);
}

.page-about .ab-tl__year {
  display: block;
  margin-bottom: 8px;
  font-size: clamp(1.6rem, 7vw, 2.3rem);
  font-weight: 700;
  line-height: 1;
  letter-spacing: -0.02em;
}

.page-about .ab-tl__title {
  margin: 0 0 8px;
  font-size: 1.1875rem;
  font-weight: 800;
  line-height: 1.42;
}

.page-about .ab-tl__text {
  margin: 0 0 10px;
  max-width: 62ch;
  font-size: 0.9375rem;
  line-height: 1.78;
  color: var(--ink-700);
}

.page-about .ab-tl__tags {
  list-style: none;
  margin: 0;
  padding: 0;
  display: flex;
  flex-wrap: wrap;
  gap: 6px;
}

/* ---------- 03 团队 ---------- */

.page-about .ab-team {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 22px;
}

.page-about .ab-team__lead {
  margin: 0 0 16px;
  font-size: 1rem;
  line-height: 1.8;
  color: var(--ink-700);
}

.page-about .ab-flow {
  list-style: none;
  margin: 0;
  padding: 0;
  display: grid;
  gap: 1px;
  background-color: var(--grid-300);
  border: 2px solid var(--ink-900);
}

.page-about .ab-flow__step {
  background-color: var(--paper-50);
  display: grid;
  grid-template-columns: 30px minmax(0, 1fr);
  gap: 10px;
  padding: 11px 12px;
  font-size: 0.875rem;
  line-height: 1.66;
  color: var(--ink-700);
}

.page-about .ab-flow__step p {
  margin: 0;
}

.page-about .ab-flow__num {
  font-size: 0.75rem;
  font-weight: 700;
  color: var(--orange-deep);
  padding-top: 3px;
}

.page-about .ab-fig {
  margin: 0;
  border: 2px solid var(--ink-900);
  box-shadow: var(--shadow-hard);
  background-color: var(--paper-200);
  min-width: 0;
}

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

.page-about .ab-fig figcaption {
  padding: 10px 12px;
  font-size: 0.8125rem;
  line-height: 1.6;
  color: var(--ink-700);
  background-color: var(--paper-50);
  border-top: 1px solid var(--grid-300);
}

.page-about .ab-shifts {
  margin-top: 24px;
  padding: 16px;
  border: 2px solid var(--ink-900);
  background-color: var(--paper-50);
}

.page-about .ab-shifts__head {
  display: flex;
  flex-wrap: wrap;
  align-items: baseline;
  justify-content: space-between;
  gap: 8px;
}

.page-about .ab-shifts__label {
  font-size: 0.75rem;
  font-weight: 700;
  letter-spacing: 0.12em;
  color: var(--green-deep);
}

.page-about .ab-shifts__note {
  font-size: 0.8125rem;
  color: var(--ink-700);
}

.page-about .ab-shifts__bars {
  list-style: none;
  margin: 14px 0 12px;
  padding: 0;
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: 4px;
}

.page-about .ab-shifts__bar {
  height: 42px;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 0.8125rem;
  font-weight: 700;
  color: var(--paper-50);
  background-color: var(--field-green);
}

.page-about .ab-shifts__bar:nth-child(2) {
  background-color: var(--green-deep);
}

.page-about .ab-shifts__bar:nth-child(3) {
  background-color: var(--ink-900);
}

.page-about .ab-shifts__cap {
  margin: 0;
  font-size: 0.875rem;
  line-height: 1.72;
  color: var(--ink-700);
}

/* ---------- 04 覆盖 ---------- */

.page-about .ab-cover__bars {
  display: grid;
  gap: 12px;
  margin-bottom: 24px;
}

.page-about .ab-bar {
  display: grid;
  grid-template-columns: 44px minmax(0, 1fr) 40px;
  align-items: center;
  gap: 10px;
}

.page-about .ab-bar__label {
  font-size: 0.875rem;
  font-weight: 700;
  color: var(--ink-700);
}

.page-about .ab-bar__track {
  display: block;
  height: 16px;
  background-color: var(--paper-200);
  border: 2px solid var(--ink-900);
  overflow: hidden;
}

.page-about .ab-bar__fill {
  display: block;
  height: 100%;
  background-color: var(--field-green);
}

.page-about .ab-bar__fill--cup {
  background-color: var(--ice-blue);
}

.page-about .ab-bar__val {
  font-size: 1.125rem;
  font-weight: 700;
  text-align: right;
}

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

.page-about .ab-groups__item {
  padding: 14px 15px 16px;
  background-color: var(--paper-50);
  border: 2px solid var(--ink-900);
  border-left: 6px solid var(--field-green);
  min-width: 0;
}

.page-about .ab-groups__item:nth-child(2) {
  border-left-color: var(--ice-blue);
}

.page-about .ab-groups__item:nth-child(3) {
  border-left-color: var(--sprint-orange);
}

.page-about .ab-groups__item:nth-child(4) {
  border-left-color: var(--ink-900);
}

.page-about .ab-groups__title {
  margin: 0 0 6px;
  font-size: 1rem;
  font-weight: 800;
  line-height: 1.42;
}

.page-about .ab-groups__text {
  margin: 0;
  font-size: 0.9rem;
  line-height: 1.72;
  color: var(--ink-700);
}

/* ---------- 05 合作生态 ---------- */

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

.page-about .ab-eco__item {
  display: flex;
  flex-direction: column;
  gap: 8px;
  padding: 18px 16px;
  background-color: var(--paper-200);
  border: 2px solid var(--ink-900);
  border-left: 6px solid var(--field-green);
  min-width: 0;
}

.page-about .ab-eco__item--media {
  background-color: var(--green-tint);
}

.page-about .ab-eco__item--data {
  background-color: var(--paper-50);
  border-left-color: var(--ice-blue);
}

.page-about .ab-eco__item--output {
  border-left-color: var(--sprint-orange);
}

.page-about .ab-eco__item--reach {
  border-left-color: var(--ink-900);
}

.page-about .ab-eco__num {
  font-size: 2rem;
  font-weight: 700;
  line-height: 1;
  letter-spacing: -0.02em;
}

.page-about .ab-eco__unit {
  margin-left: 5px;
  font-size: 0.8125rem;
  font-weight: 400;
  color: var(--ink-700);
}

.page-about .ab-eco__title {
  margin: 0;
  font-size: 1rem;
  font-weight: 800;
  line-height: 1.42;
}

.page-about .ab-eco__text {
  margin: 0;
  font-size: 0.9rem;
  line-height: 1.72;
  color: var(--ink-700);
}

/* ---------- 06 地域 ---------- */

.page-about .ab-fig--wide {
  margin-bottom: 20px;
}

.page-about .ab-roots {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 14px;
}

.page-about .ab-roots p {
  margin: 0;
  font-size: 0.9375rem;
  line-height: 1.82;
  color: var(--ink-700);
}

/* ---------- 07 四条要求 ---------- */

.page-about .ab-std {
  list-style: none;
  margin: 0;
  padding: 0;
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 1px;
  background-color: var(--grid-300);
  border: 2px solid var(--ink-900);
}

.page-about .ab-std__item {
  display: grid;
  grid-template-columns: 28px minmax(0, 1fr);
  gap: 10px;
  padding: 16px 15px 18px;
  background-color: var(--paper-50);
  min-width: 0;
}

.page-about .ab-std__num {
  padding-top: 4px;
  font-size: 0.75rem;
  font-weight: 700;
  color: var(--orange-deep);
}

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

.page-about .ab-std__title {
  margin: 0 0 6px;
  font-size: 1rem;
  font-weight: 800;
  line-height: 1.45;
}

.page-about .ab-std__text {
  margin: 0;
  font-size: 0.9rem;
  line-height: 1.74;
  color: var(--ink-700);
}

/* ---------- 结尾 ---------- */

.page-about .ab-next {
  margin-top: 44px;
  padding: 26px 20px;
  background-color: var(--ink-900);
  color: var(--paper-50);
  border: 2px solid var(--ink-900);
  box-shadow: var(--shadow-hard-lg);
}

.page-about .ab-next__title {
  margin: 0 0 10px;
  font-size: clamp(1.3rem, 4.2vw, 1.8rem);
  font-weight: 900;
  line-height: 1.25;
  letter-spacing: -0.01em;
  color: var(--paper-50);
}

.page-about .ab-next__text {
  margin: 0 0 18px;
  max-width: 58ch;
  font-size: 0.9375rem;
  line-height: 1.76;
  color: var(--paper-50);
  opacity: 0.86;
}

.page-about .ab-next__links {
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
}

.page-about .ab-next__link {
  display: inline-block;
  padding: 10px 16px;
  font-size: 0.875rem;
  font-weight: 700;
  color: var(--paper-50);
  background-color: transparent;
  border: 2px solid var(--paper-50);
  text-decoration: none;
  transition: background-color 120ms var(--ease), color 120ms var(--ease), border-color 120ms var(--ease);
}

.page-about .ab-next__link:hover {
  background-color: var(--paper-50);
  color: var(--ink-900);
}

.page-about .ab-next__link--primary {
  background-color: var(--sprint-orange);
  border-color: var(--sprint-orange);
  color: var(--ink-900);
}

.page-about .ab-next__link--primary:hover {
  background-color: var(--paper-50);
  border-color: var(--paper-50);
  color: var(--ink-900);
}

/* ---------- 响应式 ---------- */

@media (min-width: 700px) {
  .page-about .ab-wrap {
    padding: 26px 32px 84px;
  }

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

  .page-about .ab-groups {
    grid-template-columns: repeat(2, minmax(0, 1fr));
    gap: 16px;
  }

  .page-about .ab-roots {
    grid-template-columns: repeat(2, minmax(0, 1fr));
    gap: 24px;
  }

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

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

@media (min-width: 820px) {
  .page-about .ab-aud {
    grid-template-columns: repeat(3, minmax(0, 1fr));
  }

  .page-about .ab-team {
    grid-template-columns: minmax(0, 1.1fr) minmax(0, 1fr);
    align-items: start;
    gap: 30px;
  }

  .page-about .ab-eco {
    grid-template-columns: repeat(6, minmax(0, 1fr));
  }

  .page-about .ab-eco__item--wide {
    grid-column: span 4;
  }

  .page-about .ab-eco__item--narrow {
    grid-column: span 2;
  }

  .page-about .ab-eco__item--half {
    grid-column: span 3;
  }
}

@media (min-width: 900px) {
  .page-about .ab-sec {
    margin-top: 52px;
    padding-top: 40px;
  }

  .page-about .ab-tl {
    padding-left: 0;
  }

  .page-about .ab-tl::before {
    left: 168px;
  }

  .page-about .ab-tl__item {
    display: grid;
    grid-template-columns: 140px minmax(0, 1fr);
    column-gap: 48px;
    padding-bottom: 38px;
  }

  .page-about .ab-tl__item::before {
    left: 161px;
    top: 8px;
  }

  .page-about .ab-tl__year {
    margin-bottom: 0;
    text-align: right;
    font-size: clamp(1.8rem, 3vw, 2.4rem);
  }
}

@media (min-width: 1120px) {
  .page-about .ab-wrap {
    max-width: 1120px;
    margin-left: auto;
    margin-right: auto;
    padding-left: 40px;
    padding-right: 40px;
  }

  .page-about .ab-hero {
    padding-bottom: 44px;
  }
}

@media (prefers-reduced-motion: reduce) {
  .page-about *,
  .page-about *::before,
  .page-about *::after {
    animation-duration: 0.001ms !important;
    animation-iteration-count: 1 !important;
    transition-duration: 0.001ms !important;
  }

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