.page-about {
  --about-index-w: 232px;
  padding-bottom: 72px;
}

.page-about .about-shell {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 18px;
  align-items: start;
  padding-top: 22px;
}

.page-about .about-body {
  min-width: 0;
}

/* ---------- 章节索引 ---------- */
.page-about .about-index__label {
  margin: 0 0 10px;
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: 0.16em;
  text-transform: uppercase;
  color: var(--cyan);
}

.page-about .about-index__list {
  list-style: none;
  margin: 0;
  padding: 4px 0 0;
  display: flex;
  gap: 16px;
  overflow-x: auto;
  border-top: 1px solid var(--line);
  -webkit-overflow-scrolling: touch;
}

.page-about .about-index__item {
  flex: 0 0 auto;
}

.page-about .about-index__link {
  display: inline-flex;
  align-items: center;
  gap: 7px;
  min-height: 44px;
  padding: 8px 0;
  font-size: 13px;
  line-height: 1.4;
  color: var(--graphite);
  text-decoration: none;
  white-space: nowrap;
  border-top: 2px solid transparent;
  margin-top: -1px;
  transition: color 160ms var(--ease), border-color 160ms var(--ease);
}

.page-about .about-index__no {
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: 0.06em;
  color: var(--line);
}

.page-about .about-index__link:hover,
.page-about .about-index__link:focus-visible {
  color: var(--white);
  border-top-color: var(--cyan);
}

.page-about .about-index__link:hover .about-index__no,
.page-about .about-index__link:focus-visible .about-index__no {
  color: var(--cyan);
}

/* ---------- 首屏 ---------- */
.page-about .about-hero {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 24px;
  padding: 0 0 44px;
  border-bottom: 1px solid var(--line);
}

.page-about .about-hero__title {
  margin: 12px 0 0;
  font-family: var(--font-display);
  font-weight: 700;
  font-size: clamp(32px, 7.4vw, 60px);
  line-height: 1.03;
  letter-spacing: -0.01em;
  color: var(--white);
}

.page-about .about-hero__lead {
  margin: 16px 0 0;
  max-width: 34em;
  font-size: 16px;
  line-height: 1.85;
  color: var(--mist);
}

.page-about .about-hero__media {
  margin: 0;
  border: 1px solid var(--line);
  background: var(--ink-800);
  display: flex;
  flex-direction: column;
}

.page-about .about-hero__media img {
  display: block;
  width: 100%;
  aspect-ratio: 3 / 2;
  object-fit: cover;
}

.page-about .about-hero__cap {
  padding: 10px 13px;
  border-top: 1px solid var(--line);
  font-family: var(--font-mono);
  font-size: 11px;
  line-height: 1.7;
  letter-spacing: 0.03em;
  color: var(--graphite);
}

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

.page-about .about-hero__stat {
  background: var(--ink-800);
  padding: 15px 15px 17px;
}

.page-about .about-hero__stat-value {
  display: block;
  font-family: var(--font-mono);
  font-size: 21px;
  line-height: 1.25;
  letter-spacing: 0.01em;
  color: var(--white);
}

.page-about .about-hero__stat-label {
  display: block;
  margin-top: 7px;
  font-size: 12px;
  line-height: 1.6;
  letter-spacing: 0.04em;
  color: var(--graphite);
}

/* ---------- 章节通用 ---------- */
.page-about .about-section {
  border-top: 1px solid var(--line);
  padding: 34px 0 46px;
  scroll-margin-top: 92px;
}

.page-about .sec-num {
  display: block;
  margin: 0;
  font-family: var(--font-display);
  font-weight: 600;
  font-size: 42px;
  line-height: 1;
  letter-spacing: -0.02em;
  color: var(--cyan);
}

.page-about .about-section__title {
  margin: 8px 0 0;
  font-family: var(--font-display);
  font-weight: 600;
  font-size: clamp(23px, 3.6vw, 38px);
  line-height: 1.16;
  letter-spacing: -0.01em;
  color: var(--white);
}

.page-about .about-section__col {
  margin-top: 18px;
  max-width: 38em;
}

.page-about .about-section__col p,
.page-about .about-section p {
  margin: 0 0 1.05em;
  font-size: 16px;
  line-height: 1.85;
  color: var(--mist);
}

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

.page-about .about-note {
  margin-top: 20px !important;
  padding-left: 13px;
  border-left: 2px solid var(--orange);
  font-family: var(--font-mono);
  font-size: 13px !important;
  line-height: 1.8 !important;
  color: var(--graphite) !important;
}

/* ---------- 覆盖范围清单 ---------- */
.page-about .about-scope {
  list-style: none;
  margin: 24px 0 0;
  padding: 0;
  border-top: 1px solid var(--line);
}

.page-about .about-scope li {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 5px;
  padding: 12px 0;
  border-bottom: 1px solid var(--line-soft);
}

.page-about .about-scope__k {
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.08em;
  color: var(--cyan-soft);
}

.page-about .about-scope__v {
  font-size: 15px;
  line-height: 1.75;
  color: var(--mist);
}

/* ---------- 流程 ---------- */
.page-about .about-flow {
  list-style: none;
  margin: 24px 0 0;
  padding: 0;
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 1px;
  background: var(--line);
  border: 1px solid var(--line);
}

.page-about .about-flow__item {
  background: var(--ink-800);
  padding: 18px 17px 20px;
}

.page-about .about-flow__step {
  display: block;
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: 0.14em;
  color: var(--cyan);
}

.page-about .about-flow__name {
  margin: 9px 0 7px;
  font-family: var(--font-display);
  font-weight: 600;
  font-size: 21px;
  line-height: 1.2;
  color: var(--white);
}

.page-about .about-flow__desc {
  margin: 0 !important;
  font-size: 14px !important;
  line-height: 1.8 !important;
  color: var(--mist) !important;
}

.page-about .about-diagram {
  margin: 28px auto 0;
  max-width: 620px;
  border: 1px solid var(--line);
  background: var(--ink-800);
}

.page-about .about-diagram img,
.page-about .about-track-media img {
  display: block;
  width: 100%;
  height: auto;
  object-fit: cover;
}

.page-about .about-diagram figcaption {
  padding: 10px 13px;
  border-top: 1px solid var(--line);
  font-family: var(--font-mono);
  font-size: 11px;
  line-height: 1.7;
  letter-spacing: 0.03em;
  color: var(--graphite);
}

/* ---------- 团队分段切换 ---------- */
.page-about .about-tabs {
  margin-top: 24px;
}

.page-about .about-tabs .tabs__list {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
}

.page-about .about-tabs .tabs__btn {
  min-height: 44px;
  padding: 10px 16px;
  border: 1px solid var(--line);
  border-radius: 2px;
  background: var(--ink-800);
  color: var(--mist);
  font-family: var(--font-body);
  font-size: 14px;
  letter-spacing: 0.02em;
  cursor: pointer;
  transition: background 160ms var(--ease), border-color 160ms var(--ease), color 160ms var(--ease);
}

.page-about .about-tabs .tabs__btn:hover {
  border-color: var(--cyan);
  color: var(--white);
}

.page-about .about-tabs .tabs__btn[aria-selected="true"] {
  background: var(--ink-700);
  border-color: var(--cyan);
  color: var(--white);
}

.page-about .about-tabs__count {
  margin-left: 6px;
  font-family: var(--font-mono);
  font-size: 12px;
  color: var(--cyan);
}

.page-about .about-tabs .tabs__panel {
  margin-top: 16px;
  padding: 20px 18px;
  border: 1px solid var(--line);
  background: var(--ink-800);
}

.page-about .about-tabs .tabs__panel p {
  max-width: 36em;
}

.page-about .about-tabs .tabs__panel ul {
  list-style: none;
  margin: 16px 0 0;
  padding: 0;
  display: grid;
  gap: 9px;
}

.page-about .about-tabs .tabs__panel li {
  position: relative;
  padding-left: 18px;
  font-size: 14px;
  line-height: 1.8;
  color: var(--mist);
}

.page-about .about-tabs .tabs__panel li::before {
  content: "";
  position: absolute;
  left: 0;
  top: 0.82em;
  width: 9px;
  height: 1px;
  background: var(--cyan);
}

/* ---------- 轨道式时间轴 ---------- */
.page-about .about-track {
  margin-top: 26px;
}

.page-about .about-track__list {
  list-style: none;
  margin: 0;
  padding: 0 0 6px;
  display: flex;
  gap: 0;
  overflow-x: auto;
  scroll-snap-type: x proximity;
  -webkit-overflow-scrolling: touch;
}

.page-about .about-track__item {
  position: relative;
  flex: 0 0 78%;
  scroll-snap-align: start;
  padding: 24px 22px 4px 0;
  border-top: 1px solid var(--line);
}

.page-about .about-track__dot {
  position: absolute;
  top: -4px;
  left: 0;
  width: 7px;
  height: 7px;
  border-radius: 50%;
  background: var(--cyan);
  box-shadow: 0 0 0 3px rgba(47, 227, 210, 0.14);
}

.page-about .about-track__year {
  margin: 0 0 8px;
  font-family: var(--font-mono);
  font-size: 13px;
  letter-spacing: 0.1em;
  color: var(--cyan);
}

.page-about .about-track__title {
  margin: 0 0 8px;
  font-family: var(--font-display);
  font-weight: 600;
  font-size: 20px;
  line-height: 1.25;
  letter-spacing: 0.01em;
  color: var(--white);
}

.page-about .about-track__desc {
  margin: 0 !important;
  padding-right: 16px;
  font-size: 14px !important;
  line-height: 1.8 !important;
  color: var(--graphite) !important;
}

.page-about .about-track-media {
  display: block;
  margin: 30px 0 0;
  border: 1px solid var(--line);
  background: var(--ink-800);
  overflow: hidden;
}

/* ---------- 合作生态 ---------- */
.page-about .about-partners {
  margin-top: 24px;
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 20px;
  padding: 24px 20px 26px;
  border: 1px solid var(--line);
  background:
    radial-gradient(130% 150% at 0% 0%, rgba(47, 227, 210, 0.10) 0%, transparent 55%),
    var(--ink-800);
}

.page-about .about-partners__figure {
  margin: 0 !important;
  display: flex;
  flex-direction: column;
  gap: 6px;
}

.page-about .about-partners__num {
  font-family: var(--font-mono);
  font-size: 62px;
  line-height: 0.9;
  letter-spacing: -0.01em;
  color: var(--cyan);
}

.page-about .about-partners__unit {
  font-size: 13px;
  letter-spacing: 0.06em;
  color: var(--graphite);
}

.page-about .about-partners__body p {
  margin: 0 0 1em;
  max-width: 36em;
  font-size: 15px;
  line-height: 1.85;
  color: var(--mist);
}

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

/* ---------- 读者分布 ---------- */
.page-about .about-reach {
  list-style: none;
  margin: 26px 0 0;
  padding: 0;
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 1px;
  background: var(--line);
  border: 1px solid var(--line);
}

.page-about .about-reach__stat {
  background: var(--ink-800);
  padding: 17px 15px 19px;
}

.page-about .about-reach__value {
  display: block;
  font-family: var(--font-mono);
  font-size: 25px;
  line-height: 1.2;
  letter-spacing: 0.01em;
  color: var(--white);
}

.page-about .about-reach__label {
  display: block;
  margin-top: 8px;
  font-size: 12px;
  line-height: 1.65;
  letter-spacing: 0.04em;
  color: var(--graphite);
}

/* ---------- 结尾行动 ---------- */
.page-about .about-cta {
  margin-top: 40px;
  padding: 30px 20px 32px;
  border: 1px solid var(--line);
  background:
    radial-gradient(120% 150% at 100% 0%, rgba(255, 122, 31, 0.12) 0%, transparent 52%),
    var(--ink-800);
}

.page-about .about-cta__title {
  margin: 10px 0 0;
  font-family: var(--font-display);
  font-weight: 600;
  font-size: clamp(24px, 4.4vw, 38px);
  line-height: 1.14;
  letter-spacing: -0.01em;
  color: var(--white);
}

.page-about .about-cta__text {
  margin: 14px 0 0;
  max-width: 36em;
  font-size: 15px;
  line-height: 1.85;
  color: var(--mist);
}

.page-about .about-cta__actions {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
  margin-top: 24px;
}

/* ---------- 平板与桌面 ---------- */
@media (min-width: 680px) {
  .page-about .about-scope li {
    grid-template-columns: 148px minmax(0, 1fr);
    gap: 20px;
    align-items: baseline;
  }

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

@media (min-width: 900px) {
  .page-about .about-hero {
    grid-template-columns: minmax(0, 1.06fr) minmax(0, 0.94fr);
    column-gap: 40px;
  }

  .page-about .about-hero__stats {
    grid-column: 1 / -1;
  }

  .page-about .about-hero__media {
    align-self: start;
  }

  .page-about .about-hero__media img {
    aspect-ratio: 4 / 3;
  }

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

  .page-about .about-partners {
    grid-template-columns: 176px minmax(0, 1fr);
    align-items: center;
    gap: 34px;
    padding: 30px 28px 32px;
  }

  .page-about .about-track__item {
    flex: 0 0 25%;
    padding-right: 26px;
  }
}

@media (min-width: 1000px) {
  .page-about .about-shell {
    grid-template-columns: var(--about-index-w) minmax(0, 1fr);
    column-gap: 48px;
    padding-top: 30px;
  }

  .page-about .about-index {
    position: sticky;
    top: 24px;
  }

  .page-about .about-index__list {
    flex-direction: column;
    gap: 0;
    overflow: visible;
    border-top: 0;
    border-left: 1px solid var(--line);
    padding-top: 0;
  }

  .page-about .about-index__item {
    flex: initial;
  }

  .page-about .about-index__link {
    display: flex;
    padding: 11px 0 11px 15px;
    border-top: 0;
    border-left: 2px solid transparent;
    margin-top: 0;
    margin-left: -1px;
    min-height: 0;
    white-space: normal;
  }

  .page-about .about-index__link:hover,
  .page-about .about-index__link:focus-visible {
    border-top-color: transparent;
    border-left-color: var(--cyan);
  }

  .page-about .sec-num {
    font-size: 76px;
  }

  .page-about .about-section {
    padding: 42px 0 58px;
  }

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

  .page-about .about-diagram {
    margin-left: 0;
  }

  .page-about .about-partners__num {
    font-size: 76px;
  }
}

@media (min-width: 1280px) {
  .page-about .about-hero__title {
    font-size: 60px;
  }
}

@media (prefers-reduced-motion: reduce) {
  .page-about .about-index__link,
  .page-about .about-tabs .tabs__btn {
    transition: none;
  }
}