.page-about {
  background: var(--navy);
  color: var(--ice-soft);
  overflow-x: clip;
}

/* ============ 首屏 ============ */
.page-about .about-hero {
  position: relative;
  overflow: hidden;
  padding: 26px 0 46px;
  background: linear-gradient(172deg, var(--navy-3) 0%, var(--navy) 46%, var(--navy-2) 100%);
  border-bottom: 1px solid var(--line);
}

.page-about .about-hero__media {
  position: absolute;
  inset: 0;
  z-index: 0;
}

.page-about .about-hero__media img {
  width: 100%;
  height: 100%;
  object-fit: cover;
  opacity: .20;
  filter: saturate(.75) contrast(1.06);
}

.page-about .about-hero__media::after {
  content: "";
  position: absolute;
  inset: 0;
  background:
    radial-gradient(52% 68% at 84% 8%, rgba(127, 196, 232, .20), transparent 64%),
    radial-gradient(46% 62% at 6% 98%, rgba(216, 38, 44, .18), transparent 68%),
    linear-gradient(180deg, rgba(9, 23, 41, .90) 0%, rgba(11, 27, 51, .74) 48%, rgba(18, 42, 74, .96) 100%);
}

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

.page-about .about-hero .crumbs {
  margin-bottom: 20px;
}

.page-about .about-hero__label {
  margin: 0 0 14px;
}

.page-about .about-hero h1 {
  font-family: var(--font-head);
  font-weight: 800;
  font-size: 30px;
  line-height: 1.22;
  letter-spacing: -.01em;
  color: var(--paper);
  margin: 0;
  max-width: 20ch;
}

.page-about .about-hero__lead {
  margin: 16px 0 0;
  font-size: 16px;
  line-height: 1.85;
  color: var(--ice-soft);
  max-width: 58ch;
}

.page-about .about-hero__facts {
  display: flex;
  flex-wrap: wrap;
  gap: 16px 28px;
  list-style: none;
  margin: 26px 0 0;
  padding: 20px 0 0;
  border-top: 1px solid var(--line);
}

.page-about .about-hero__facts li {
  display: flex;
  flex-direction: column;
  gap: 4px;
  min-width: 132px;
}

.page-about .about-hero__fact-k {
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: .1em;
  color: var(--ice);
  opacity: .8;
}

.page-about .about-hero__fact-v {
  font-family: var(--font-head);
  font-weight: 700;
  font-size: 20px;
  line-height: 1.3;
  color: var(--paper);
}

/* ============ 主体骨架 ============ */
.page-about .about-body {
  padding: 40px 0 64px;
}

.page-about .split {
  display: grid;
  grid-template-columns: 1fr;
  gap: 30px;
  align-items: start;
}

.page-about .about-rail {
  border-bottom: 1px solid var(--line);
  padding-bottom: 12px;
}

.page-about .about-rail .rail__title {
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: .14em;
  color: var(--ice);
  opacity: .8;
  margin: 0 0 10px;
}

.page-about .about-rail .rail__list {
  list-style: none;
  margin: 0;
  padding: 0;
  display: flex;
  flex-wrap: nowrap;
  gap: 8px;
  overflow-x: auto;
  -webkit-overflow-scrolling: touch;
  scrollbar-width: thin;
  padding-bottom: 4px;
}

.page-about .about-rail .rail__list li {
  flex: 0 0 auto;
}

.page-about .rail__link {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 7px 14px;
  border: 1px solid var(--line);
  border-radius: var(--radius-pill);
  font-size: 13px;
  line-height: 1.4;
  color: var(--gray);
  text-decoration: none;
  white-space: nowrap;
  transition: color .2s ease, border-color .2s ease, background-color .2s ease;
}

.page-about .rail__link .rail__no {
  font-family: var(--font-mono);
  font-size: 11px;
  color: var(--ice);
  opacity: .75;
}

.page-about .rail__link:hover,
.page-about .rail__link:focus-visible {
  color: var(--paper);
  border-color: var(--line-strong);
  background: rgba(127, 196, 232, .09);
}

.page-about .rail__link.is-active {
  color: var(--navy);
  background: var(--ice);
  border-color: var(--ice);
}

.page-about .rail__link.is-active .rail__no {
  color: var(--navy);
  opacity: .72;
}

/* ============ 章节通用 ============ */
.page-about .about-section {
  padding: 0 0 46px;
}

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

.page-about .about-section .section__head {
  display: block;
  margin-bottom: 20px;
}

.page-about .about-section .section__no {
  display: inline-block;
  font-size: 12px;
  letter-spacing: .12em;
  color: var(--ice);
  border: 1px solid var(--line-strong);
  border-radius: 3px;
  padding: 2px 8px;
  margin-bottom: 12px;
}

.page-about .about-section .section__title {
  font-family: var(--font-head);
  font-weight: 700;
  font-size: 25px;
  line-height: 1.28;
  letter-spacing: -.005em;
  color: var(--paper);
  margin: 0;
}

.page-about .about-section .section__lead {
  margin: 10px 0 0;
  font-size: 15px;
  line-height: 1.8;
  color: var(--gray);
  max-width: 56ch;
}

/* ============ 01 我们在做的事 ============ */
.page-about .about-mission {
  border-left: 2px solid var(--maple);
  padding-left: 16px;
}

.page-about .about-mission p {
  margin: 0 0 16px;
  font-size: 16px;
  line-height: 1.9;
  color: var(--ice-soft);
  max-width: 60ch;
}

.page-about .about-mission p:last-child {
  margin-bottom: 0;
  color: var(--gray);
}

/* ============ 02 历程 ============ */
.page-about .milestones {
  display: flex;
  flex-wrap: wrap;
  gap: 14px;
  list-style: none;
  margin: 0;
  padding: 0;
}

.page-about .milestone {
  flex: 1 1 100%;
}

.page-about .milestone__d {
  background: var(--navy-2);
  border: 1px solid var(--line);
  clip-path: polygon(14px 0, 100% 0, 100% 100%, 0 100%, 0 14px);
  padding: 18px 18px 16px;
}

.page-about .milestone__sum {
  display: flex;
  align-items: center;
  gap: 12px;
  cursor: pointer;
  list-style: none;
  margin: 0;
}

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

.page-about .milestone__year {
  font-size: 18px;
  font-weight: 500;
  color: var(--navy);
  background: var(--ice);
  padding: 4px 10px;
  flex: 0 0 auto;
  clip-path: polygon(8px 0, 100% 0, 100% 100%, 0 100%, 0 8px);
}

.page-about .milestone__name {
  flex: 1 1 auto;
  font-size: 16px;
  font-weight: 700;
  color: var(--paper);
  line-height: 1.4;
}

.page-about .milestone__toggle {
  position: relative;
  flex: 0 0 auto;
  width: 18px;
  height: 18px;
  border: 1px solid var(--line-strong);
  border-radius: 50%;
}

.page-about .milestone__toggle::before,
.page-about .milestone__toggle::after {
  content: "";
  position: absolute;
  top: 50%;
  left: 50%;
  background: var(--ice);
  transform: translate(-50%, -50%);
}

.page-about .milestone__toggle::before {
  width: 8px;
  height: 1px;
}

.page-about .milestone__toggle::after {
  width: 1px;
  height: 8px;
  transition: transform .2s ease, opacity .2s ease;
}

.page-about .milestone__d[open] .milestone__toggle::after {
  transform: translate(-50%, -50%) scaleY(0);
  opacity: 0;
}

.page-about .milestone__text {
  margin: 14px 0 0;
  font-size: 15px;
  line-height: 1.85;
  color: var(--gray);
  max-width: 58ch;
}

/* ============ 03 团队 ============ */
.page-about .team-grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: 14px;
}

.page-about .team-card {
  background: linear-gradient(180deg, rgba(127, 196, 232, .07) 0%, rgba(18, 42, 74, .92) 100%);
  border: 1px solid var(--line);
  border-top: 2px solid var(--maple);
  padding: 20px 18px 22px;
}

.page-about .team-card__no {
  display: block;
  font-size: 11px;
  letter-spacing: .12em;
  color: var(--ice);
  opacity: .8;
  margin-bottom: 10px;
}

.page-about .team-card__title {
  font-family: var(--font-head);
  font-weight: 700;
  font-size: 19px;
  color: var(--paper);
  margin: 0 0 10px;
}

.page-about .team-card__text {
  margin: 0;
  font-size: 15px;
  line-height: 1.85;
  color: var(--gray);
}

/* ============ 04 字段表 ============ */
.page-about .about-fields {
  display: grid;
  grid-template-columns: 1fr;
  gap: 20px;
}

.page-about .about-ledger {
  background: var(--paper);
  clip-path: polygon(20px 0, 100% 0, 100% 100%, 0 100%, 0 20px);
  padding: 6px 18px;
}

.page-about .about-ledger .ledger__row {
  display: grid;
  grid-template-columns: 1fr;
  gap: 4px;
  padding: 16px 0;
  border-bottom: 1px dashed rgba(27, 36, 48, .18);
}

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

.page-about .about-ledger .ledger__key {
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: .06em;
  color: var(--navy);
  background: var(--ice-soft);
  display: inline-block;
  padding: 3px 9px;
  justify-self: start;
}

.page-about .about-ledger .ledger__val {
  font-size: 15px;
  line-height: 1.8;
  color: rgba(27, 36, 48, .82);
}

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

.page-about .about-fields__fig .figure__frame {
  border: 1px solid var(--line);
  background: var(--navy-2);
}

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

.page-about .about-fields__fig .figure__cap {
  font-size: 13px;
  line-height: 1.7;
  color: var(--gray);
  margin-top: 10px;
}

/* ============ 05 节奏与路径 ============ */
.page-about .cadence-grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: 14px;
  margin-bottom: 22px;
}

.page-about .cadence-card {
  border: 1px solid var(--line);
  padding: 18px 18px 20px;
  background: rgba(18, 42, 74, .72);
}

.page-about .cadence-card--live {
  border-left: 3px solid var(--amber);
}

.page-about .cadence-card--weekly {
  border-left: 3px solid var(--maple);
}

.page-about .cadence-card .tag {
  margin-bottom: 12px;
}

.page-about .cadence-card__title {
  font-family: var(--font-head);
  font-weight: 700;
  font-size: 18px;
  color: var(--paper);
  margin: 0 0 10px;
}

.page-about .cadence-card__text {
  margin: 0;
  font-size: 15px;
  line-height: 1.85;
  color: var(--gray);
}

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

.page-about .path-list__item {
  display: grid;
  grid-template-columns: 42px 1fr;
  gap: 12px;
  align-items: start;
  padding: 16px 0;
  border-bottom: 1px dashed var(--line);
}

.page-about .path-list__no {
  font-size: 20px;
  line-height: 1.2;
  color: var(--maple-soft);
  font-weight: 500;
}

.page-about .path-list__title {
  font-family: var(--font-head);
  font-weight: 700;
  font-size: 17px;
  color: var(--paper);
  margin: 0 0 6px;
}

.page-about .path-list__text {
  margin: 0;
  font-size: 15px;
  line-height: 1.8;
  color: var(--gray);
}

/* ============ 06 覆盖范围 ============ */
.page-about .about-coverage__fig {
  margin: 0 0 22px;
  border: 1px solid var(--line);
  background: var(--navy-2);
}

.page-about .about-coverage__fig .figure__frame {
  display: block;
}

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

.page-about .about-coverage__fig .figure__cap {
  display: block;
  font-size: 13px;
  line-height: 1.7;
  color: var(--gray);
  padding: 12px 16px 14px;
  border-top: 1px solid var(--line);
}

.page-about .scene-list {
  list-style: none;
  margin: 0;
  padding: 0;
  display: grid;
  grid-template-columns: 1fr;
  gap: 12px;
}

.page-about .scene-item {
  border-left: 2px solid var(--ice);
  padding: 2px 0 2px 14px;
}

.page-about .scene-item__title {
  font-size: 15px;
  font-weight: 700;
  color: var(--ice-soft);
  margin: 0 0 6px;
}

.page-about .scene-item__text {
  margin: 0;
  font-size: 14px;
  line-height: 1.8;
  color: var(--gray);
}

/* ============ 07 协作 ============ */
.page-about .about-partners {
  background: var(--navy-2);
  border: 1px solid var(--line);
  clip-path: polygon(14px 0, 100% 0, 100% 100%, 0 100%, 0 14px);
  padding: 20px 18px 22px;
}

.page-about .about-partners p {
  margin: 0 0 14px;
  font-size: 15px;
  line-height: 1.9;
  color: var(--gray);
  max-width: 60ch;
}

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

/* ============ 08 联络 ============ */
.page-about .about-contact__panel {
  background:
    radial-gradient(60% 80% at 92% 6%, rgba(245, 179, 27, .18), transparent 62%),
    linear-gradient(160deg, var(--navy-2) 0%, var(--navy) 100%);
  border: 1px solid var(--line-strong);
  padding: 24px 20px 26px;
}

.page-about .about-contact__title {
  font-family: var(--font-head);
  font-weight: 700;
  font-size: 23px;
  color: var(--paper);
  margin: 12px 0 12px;
}

.page-about .about-contact__lead {
  margin: 0 0 20px;
  font-size: 15px;
  line-height: 1.85;
  color: var(--gray);
  max-width: 56ch;
}

.page-about .about-contact__list {
  margin: 0 0 22px;
  border-top: 1px solid var(--line);
}

.page-about .about-contact__row {
  display: grid;
  grid-template-columns: 1fr;
  gap: 4px;
  padding: 12px 0;
  border-bottom: 1px dashed var(--line);
}

.page-about .about-contact__key {
  font-size: 11px;
  letter-spacing: .12em;
  color: var(--ice);
  opacity: .82;
}

.page-about .about-contact__val {
  margin: 0;
  font-family: var(--font-mono);
  font-size: 16px;
  font-weight: 500;
  color: var(--paper);
  word-break: break-word;
}

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

/* ============ 响应式 ============ */
@media (min-width: 620px) {
  .page-about .about-hero {
    padding: 34px 0 60px;
  }

  .page-about .about-hero h1 {
    font-size: 40px;
    max-width: 22ch;
  }

  .page-about .about-hero__lead {
    font-size: 17px;
  }

  .page-about .about-hero__fact-v {
    font-size: 22px;
  }

  .page-about .about-section .section__title {
    font-size: 30px;
  }

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

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

  .page-about .scene-list {
    grid-template-columns: repeat(2, 1fr);
    gap: 18px 22px;
  }

  .page-about .about-ledger .ledger__row {
    grid-template-columns: 130px 1fr;
    gap: 16px;
    align-items: baseline;
  }

  .page-about .about-contact__row {
    grid-template-columns: 120px 1fr;
    align-items: baseline;
    gap: 16px;
  }
}

@media (min-width: 800px) {
  .page-about .milestone--a {
    flex: 1 1 44%;
  }

  .page-about .milestone--b {
    flex: 1 1 50%;
  }

  .page-about .milestone--c {
    flex: 1 1 100%;
  }
}

@media (min-width: 900px) {
  .page-about .split {
    grid-template-columns: minmax(194px, 23%) 1fr;
    gap: 46px;
  }

  .page-about .about-rail {
    position: sticky;
    top: 108px;
    border-bottom: 0;
    border-left: 2px solid var(--line-strong);
    padding: 0 0 0 16px;
    align-self: start;
  }

  .page-about .about-rail .rail__list {
    display: block;
    overflow: visible;
    padding-bottom: 0;
  }

  .page-about .about-rail .rail__list li {
    display: block;
  }

  .page-about .rail__link {
    display: flex;
    width: 100%;
    border: 0;
    border-radius: 0;
    background: none;
    padding: 8px 0;
    white-space: normal;
    font-size: 14px;
    align-items: baseline;
  }

  .page-about .rail__link.is-active {
    color: var(--maple-soft);
    background: none;
    box-shadow: inset 2px 0 0 var(--maple-soft);
    padding-left: 10px;
  }

  .page-about .rail__link.is-active .rail__no {
    color: var(--maple-soft);
    opacity: 1;
  }

  .page-about .team-grid {
    grid-template-columns: 1.15fr .95fr .95fr;
    gap: 16px;
  }

  .page-about .team-card:nth-child(2) {
    transform: translateY(18px);
  }

  .page-about .team-card:nth-child(3) {
    transform: translateY(6px);
  }

  .page-about .about-fields {
    grid-template-columns: 1.35fr .85fr;
    gap: 26px;
    align-items: start;
  }

  .page-about .about-coverage__fig {
    margin-bottom: 26px;
  }
}

@media (min-width: 1080px) {
  .page-about .about-hero h1 {
    font-size: 48px;
  }

  .page-about .about-section .section__title {
    font-size: 33px;
  }

  .page-about .about-body {
    padding: 52px 0 76px;
  }
}

@media (prefers-reduced-motion: reduce) {
  .page-about .rail__link,
  .page-about .milestone__toggle::after {
    transition: none;
  }

  .page-about .team-card:nth-child(2),
  .page-about .team-card:nth-child(3) {
    transform: none;
  }
}
<<<END>>>