.page-about {
  --about-gap: 48px;
  --about-track: 2px;
  position: relative;
  overflow-x: clip;
}

/* ---------- 首屏 ---------- */
.page-about .about-hero {
  position: relative;
  padding-top: calc(var(--header-h) + 40px);
  background:
    radial-gradient(120% 68% at 82% 4%, rgba(47, 227, 180, .13), transparent 62%),
    radial-gradient(80% 50% at 8% 96%, rgba(255, 123, 51, .09), transparent 70%),
    linear-gradient(180deg, #0D1E2B 0%, #060B12 100%);
  overflow: hidden;
}

.page-about .about-hero::after {
  content: "";
  position: absolute;
  inset: 0;
  background-image:
    linear-gradient(rgba(30, 50, 64, .55) 1px, transparent 1px),
    linear-gradient(90deg, rgba(30, 50, 64, .55) 1px, transparent 1px);
  background-size: 64px 64px;
  -webkit-mask-image: radial-gradient(92% 76% at 50% 26%, #000 10%, transparent 78%);
  mask-image: radial-gradient(92% 76% at 50% 26%, #000 10%, transparent 78%);
  opacity: .6;
  pointer-events: none;
}

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

.page-about .breadcrumbs {
  display: flex;
  align-items: center;
  gap: 10px;
  font-family: var(--font-mono);
  font-size: 13px;
  letter-spacing: .04em;
  color: var(--steel);
}

.page-about .breadcrumbs__link {
  color: var(--steel);
  text-decoration: none;
  transition: color .16s var(--ease);
}

.page-about .breadcrumbs__link:hover {
  color: var(--teal);
}

.page-about .breadcrumbs__item {
  color: var(--mist);
}

.page-about .breadcrumbs__item::before {
  content: "/";
  margin-right: 10px;
  color: var(--line);
}

.page-about .about-hero__grid {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 40px;
  padding: 44px 0 72px;
}

.page-about .about-hero__lead .eyebrow {
  color: var(--teal);
}

.page-about .about-hero__title {
  font-family: var(--font-display);
  font-weight: 800;
  font-size: clamp(38px, 8vw, 88px);
  line-height: 1.02;
  letter-spacing: -0.02em;
  color: var(--mist);
  margin: 18px 0 0;
  max-width: 15ch;
}

.page-about .about-hero__copy {
  margin: 24px 0 0;
  max-width: 56ch;
  font-size: 17px;
  line-height: 1.75;
  color: var(--steel);
}

.page-about .about-board {
  border: 1px solid var(--line);
  border-radius: var(--radius-lg);
  background: linear-gradient(180deg, rgba(20, 24, 29, .92), rgba(16, 23, 32, .78));
  padding: 22px 24px 10px;
}

.page-about .about-board__label {
  margin: 0 0 6px;
  font-size: 12px;
  letter-spacing: .08em;
  text-transform: uppercase;
  color: var(--steel);
}

.page-about .about-board__list {
  list-style: none;
  margin: 0;
  padding: 0;
}

.page-about .about-board__row {
  display: flex;
  align-items: baseline;
  justify-content: space-between;
  gap: 16px;
  padding: 13px 0;
  border-bottom: 1px solid var(--line);
}

.page-about .about-board__row:last-child {
  border-bottom: 0;
}

.page-about .about-board__key {
  font-size: 14px;
  color: var(--steel);
}

.page-about .about-board__val {
  font-size: 17px;
  font-weight: 600;
  color: var(--mist);
}

/* ---------- sticky 状态条 ---------- */
.page-about .about-resultbar {
  position: sticky;
  top: var(--header-h);
  z-index: 30;
  background: rgba(10, 22, 34, .92);
  -webkit-backdrop-filter: blur(12px);
  backdrop-filter: blur(12px);
  border-bottom: 1px solid var(--line);
}

.page-about .about-resultbar .result-bar {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 10px 14px;
  padding: 12px 0;
}

.page-about .about-resultbar .result-bar__label {
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: .08em;
  color: var(--steel);
}

.page-about .about-resultbar .result-bar__value {
  font-size: 14px;
  color: var(--mist);
}

/* ---------- 主骨架 ---------- */
.page-about .about-spine {
  position: relative;
  padding: 8px 0 88px;
  background: var(--ink);
}

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

.page-about .about-rail {
  display: none;
}

.page-about .about-stream {
  position: relative;
  min-width: 0;
}

/* ---------- 章节 ---------- */
.page-about .about-chapter {
  padding: 64px 0 16px;
  border-top: 1px solid var(--line);
}

.page-about .about-chapter:first-child {
  border-top: 0;
  padding-top: 40px;
}

.page-about .about-chapter__index {
  margin: 0 0 14px;
  font-size: 12px;
  letter-spacing: .12em;
  text-transform: uppercase;
  color: var(--orange);
}

.page-about .about-chapter__title {
  margin: 0;
  font-family: var(--font-display);
  font-weight: 800;
  font-size: clamp(26px, 4.6vw, 46px);
  line-height: 1.1;
  letter-spacing: -0.015em;
  color: var(--mist);
  max-width: 22ch;
}

.page-about .about-chapter__lede {
  margin: 20px 0 0;
  max-width: 42ch;
  font-family: var(--font-serif);
  font-style: italic;
  font-size: 20px;
  line-height: 1.6;
  color: var(--teal);
}

.page-about .about-chapter p {
  color: var(--steel);
  font-size: 16px;
  line-height: 1.78;
}

/* ---------- 时间线 ---------- */
.page-about .about-timeline__backdrop {
  position: absolute;
  right: -8%;
  top: 6%;
  width: 76%;
  margin: 0;
  opacity: .16;
  pointer-events: none;
  z-index: 0;
  -webkit-mask-image: radial-gradient(70% 70% at 60% 40%, #000, transparent 76%);
  mask-image: radial-gradient(70% 70% at 60% 40%, #000, transparent 76%);
}

.page-about .about-timeline__backdrop img {
  display: block;
  width: 100%;
  height: auto;
  object-fit: cover;
  border-radius: var(--radius-lg);
}

.page-about .about-timeline {
  position: relative;
  z-index: 1;
  list-style: none;
  margin: 44px 0 0;
  padding: 0 0 0 28px;
}

.page-about .about-timeline::before {
  content: "";
  position: absolute;
  left: 5px;
  top: 10px;
  bottom: 18px;
  width: var(--about-track);
  border-radius: 2px;
  background: linear-gradient(180deg, var(--teal) 0%, var(--teal-deep) 42%, var(--orange) 100%);
  opacity: .75;
}

.page-about .about-timeline .timeline__item {
  position: relative;
  padding: 0 0 38px;
}

.page-about .about-timeline .timeline__item::before {
  content: "";
  position: absolute;
  left: -28px;
  top: 6px;
  width: 12px;
  height: 12px;
  border-radius: 50%;
  background: var(--ink);
  border: 2px solid var(--teal);
  box-shadow: 0 0 0 4px rgba(47, 227, 180, .12);
}

.page-about .about-timeline .timeline__item[data-tone="orange"]::before {
  border-color: var(--orange);
  box-shadow: 0 0 0 4px rgba(255, 123, 51, .14);
}

.page-about .about-timeline .timeline__meta {
  margin: 0 0 6px;
  font-size: 13px;
  letter-spacing: .06em;
  color: var(--steel);
}

.page-about .about-timeline .timeline__title {
  margin: 0 0 8px;
  font-size: 20px;
  font-weight: 600;
  line-height: 1.35;
  color: var(--mist);
}

.page-about .about-timeline .timeline__body {
  margin: 0;
  max-width: 60ch;
  font-size: 16px;
  line-height: 1.78;
  color: var(--steel);
}

/* ---------- 数据条 ---------- */
.page-about .about-metrics {
  list-style: none;
  margin: 40px 0 0;
  padding: 0;
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 0 24px;
}

.page-about .about-metric {
  position: relative;
  padding: 20px 0 18px;
  border-top: 2px solid var(--line);
}

.page-about .about-metric::after {
  content: "";
  position: absolute;
  left: 0;
  top: -2px;
  height: 2px;
  width: var(--fill, 60%);
  background: linear-gradient(90deg, var(--teal), var(--orange));
  transform: scaleX(0);
  transform-origin: left center;
  transition: transform .8s var(--ease);
}

.page-about .about-metric.is-visible::after {
  transform: scaleX(1);
}

.page-about .about-metric:nth-child(1) { --fill: 42%; }
.page-about .about-metric:nth-child(2) { --fill: 96%; }
.page-about .about-metric:nth-child(3) { --fill: 68%; }
.page-about .about-metric:nth-child(4) { --fill: 34%; }
.page-about .about-metric:nth-child(5) { --fill: 52%; }

.page-about .about-metric__num {
  display: block;
  font-size: clamp(30px, 6vw, 46px);
  font-weight: 700;
  letter-spacing: -0.01em;
  line-height: 1.1;
  color: var(--mist);
}

.page-about .about-metric__unit {
  display: block;
  margin-top: 6px;
  font-size: 13px;
  color: var(--steel);
}

.page-about .about-note-grid {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 20px;
  margin-top: 44px;
}

.page-about .about-note {
  border: 1px solid var(--line);
  border-radius: var(--radius-md);
  background: var(--panel-2);
  padding: 22px 22px 18px;
}

.page-about .about-note .heading {
  margin: 0 0 10px;
  font-size: 18px;
  font-weight: 600;
  color: var(--mist);
}

.page-about .about-note p {
  margin: 0;
}

/* ---------- 团队 ---------- */
.page-about .about-team {
  margin-top: 36px;
}

.page-about .about-team__summary {
  border-left: 3px solid var(--teal);
  padding: 4px 0 4px 20px;
  margin-bottom: 32px;
}

.page-about .about-team__num {
  margin: 0;
  font-size: clamp(46px, 11vw, 84px);
  font-weight: 700;
  line-height: 1;
  letter-spacing: -0.02em;
  color: var(--mist);
}

.page-about .about-team__desc {
  margin: 12px 0 0;
  max-width: 52ch;
}

.page-about .about-team__list {
  list-style: none;
  margin: 0;
  padding: 0;
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 18px;
}

.page-about .about-team__item {
  border: 1px solid var(--line);
  border-radius: var(--radius-md);
  background: var(--panel);
  padding: 20px 20px 16px;
}

.page-about .about-team__key {
  margin: 0 0 10px;
  font-size: 13px;
  letter-spacing: .1em;
  color: var(--orange);
}

.page-about .about-team__item .heading {
  margin: 0 0 8px;
  font-size: 19px;
  font-weight: 600;
  color: var(--mist);
}

.page-about .about-team__item p:last-child {
  margin: 0;
}

.page-about .about-team__media {
  margin: 32px 0 0;
}

.page-about .media-frame__caption {
  display: block;
  margin-top: 12px;
  font-size: 13px;
  line-height: 1.7;
  color: var(--steel);
}

.page-about .about-team__media img,
.page-about .about-partners__media img {
  display: block;
  width: 100%;
  height: auto;
  border-radius: var(--radius-md);
  object-fit: cover;
}

/* ---------- 版本与值守 ---------- */
.page-about .about-cadence {
  list-style: none;
  margin: 36px 0 0;
  padding: 0;
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 0;
}

.page-about .about-cadence__item {
  padding: 22px 0;
  border-top: 1px solid var(--line);
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 10px;
}

.page-about .about-cadence__item:last-child {
  border-bottom: 1px solid var(--line);
}

.page-about .about-cadence__label {
  font-size: 12px;
  letter-spacing: .1em;
  text-transform: uppercase;
  color: var(--teal);
}

.page-about .about-cadence__item p {
  margin: 0;
}

.page-about .about-inline-links {
  display: flex;
  flex-wrap: wrap;
  gap: 14px 26px;
  margin-top: 32px;
}

.page-about .about-inline-link {
  font-size: 15px;
  color: var(--mist);
  text-decoration: none;
  border-bottom: 1px solid var(--teal-deep);
  padding-bottom: 2px;
  transition: color .16s var(--ease), border-color .16s var(--ease);
}

.page-about .about-inline-link:hover {
  color: var(--teal);
  border-color: var(--teal);
}

/* ---------- 合作生态 ---------- */
.page-about .about-partners {
  margin-top: 32px;
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 32px;
}

.page-about .about-partners__text p {
  margin: 0 0 18px;
  max-width: 58ch;
}

.page-about .about-facts {
  list-style: none;
  margin: 24px 0 0;
  padding: 0;
  display: grid;
  gap: 12px;
}

.page-about .about-facts__item {
  display: flex;
  align-items: baseline;
  gap: 10px;
  font-size: 15px;
  color: var(--mist);
  padding-bottom: 12px;
  border-bottom: 1px solid var(--line);
}

.page-about .about-facts__item .mono {
  font-size: 18px;
  font-weight: 700;
  min-width: 2ch;
}

.page-about .about-partners__media {
  margin: 0;
}

/* ---------- 服务理念 ---------- */
.page-about .about-belief__body {
  margin: 22px 0 0;
  max-width: 62ch;
}

.page-about .about-cta {
  display: flex;
  flex-wrap: wrap;
  gap: 14px;
  margin-top: 32px;
}

.page-about .about-links {
  list-style: none;
  margin: 26px 0 0;
  padding: 0;
  display: grid;
  gap: 10px;
}

.page-about .about-links__item {
  font-size: 14px;
  color: var(--steel);
  text-decoration: none;
  transition: color .16s var(--ease);
}

.page-about .about-links__item:hover {
  color: var(--teal);
}

/* ---------- 破格斜向色块 ---------- */
.page-about .about-slant {
  height: 120px;
  margin: 0;
  border-radius: 0;
  background: linear-gradient(90deg, rgba(47, 227, 180, .16), rgba(255, 123, 51, .12) 60%, transparent);
  transform: skewY(-3.5deg);
  transform-origin: left center;
}

/* ---------- 断点 ---------- */
@media (min-width: 640px) {
  .page-about .about-metrics {
    grid-template-columns: repeat(3, minmax(0, 1fr));
  }

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

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

  .page-about .about-cadence__item {
    grid-template-columns: 140px minmax(0, 1fr);
    align-items: baseline;
    gap: 20px;
  }
}

@media (min-width: 900px) {
  .page-about .about-hero__grid {
    grid-template-columns: minmax(0, 7fr) minmax(0, 5fr);
    align-items: end;
    gap: 56px;
    padding: 56px 0 96px;
  }

  .page-about .about-metrics {
    grid-template-columns: repeat(5, minmax(0, 1fr));
  }

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

  .page-about .about-chapter {
    padding: 104px 0 24px;
  }

  .page-about .about-chapter:first-child {
    padding-top: 56px;
  }
}

@media (min-width: 1000px) {
  .page-about .about-spine__grid {
    grid-template-columns: minmax(0, 3fr) minmax(0, 9fr);
    column-gap: var(--about-gap);
  }

  .page-about .about-rail {
    display: block;
    position: relative;
  }

  .page-about .about-rail__sticky {
    position: sticky;
    top: calc(var(--header-h) + 84px);
    padding: 56px 0 0;
  }

  .page-about .about-rail__caption {
    margin: 0 0 16px;
    font-size: 11px;
    letter-spacing: .14em;
    text-transform: uppercase;
    color: var(--steel);
  }

  .page-about .about-rail__nav {
    display: flex;
    flex-direction: column;
    gap: 2px;
    border-left: 1px solid var(--line);
  }

  .page-about .about-rail__nav .anchor-nav__link {
    display: flex;
    align-items: baseline;
    gap: 10px;
    padding: 7px 0 7px 12px;
    font-size: 13px;
    line-height: 1.5;
    color: var(--steel);
    text-decoration: none;
    border-left: 2px solid transparent;
    margin-left: -1.5px;
    transition: color .16s var(--ease), border-color .16s var(--ease);
  }

  .page-about .about-rail__nav .anchor-nav__link:hover {
    color: var(--mist);
  }

  .page-about .about-rail__nav .anchor-nav__link.is-active {
    color: var(--teal);
    border-left-color: var(--teal);
  }

  .page-about .about-rail__tick {
    font-size: 11px;
    letter-spacing: .06em;
    color: var(--line);
    transition: color .16s var(--ease);
  }

  .page-about .about-rail__nav .anchor-nav__link.is-active .about-rail__tick {
    color: var(--orange);
  }

  .page-about .about-stream::before {
    content: "";
    position: absolute;
    top: 40px;
    bottom: 24px;
    left: -24px;
    width: var(--about-track);
    border-radius: 2px;
    background: linear-gradient(180deg, transparent, var(--line) 10%, var(--line) 90%, transparent);
    pointer-events: none;
  }

  .page-about .about-timeline__backdrop {
    right: -14%;
    width: 62%;
  }
}

@media (prefers-reduced-motion: reduce) {
  .page-about .about-metric::after {
    transform: scaleX(1);
    transition: none;
  }
}