.page-about {
  --about-rail: 96px;
  --about-node-bg: var(--deep);
  --about-track-x: 196px;
  background: var(--deep);
  color: var(--paper);
  overflow-x: hidden;
}

.page-about a {
  color: inherit;
}

/* ---------- 浮标索引 ---------- */
.page-about .about-index {
  display: none;
}

.page-about .about-index__list {
  list-style: none;
  margin: 0;
  padding: 0;
  display: flex;
  flex-direction: column;
  gap: 14px;
}

.page-about .about-index__link {
  display: flex;
  align-items: center;
  gap: 8px;
  font-size: 12px;
  letter-spacing: .08em;
  color: var(--mist);
  text-decoration: none;
  transition: color .2s var(--ease);
}

.page-about .about-index__link .mono {
  font-family: var(--font-mono);
  font-size: 11px;
  color: var(--line);
}

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

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

/* ---------- 首屏框景 ---------- */
.page-about .about-hero {
  padding: calc(var(--header-h) + 32px) var(--gutter) 0;
}

.page-about .about-frame {
  position: relative;
  max-width: var(--maxw);
  margin: 0 auto;
  padding: 28px clamp(20px, 4vw, 64px) 52px;
  border: 1px solid var(--line);
  background:
    radial-gradient(120% 90% at 100% 0%, rgba(63, 224, 208, .12), transparent 58%),
    radial-gradient(90% 80% at 0% 100%, rgba(122, 31, 61, .28), transparent 62%),
    var(--deep);
}

.page-about .about-corner {
  position: absolute;
  width: 20px;
  height: 20px;
  border: 0 solid var(--cyan);
  pointer-events: none;
}

.page-about .about-corner--tl {
  top: -1px;
  left: -1px;
  border-top-width: 2px;
  border-left-width: 2px;
}

.page-about .about-corner--tr {
  top: -1px;
  right: -1px;
  border-top-width: 2px;
  border-right-width: 2px;
}

.page-about .about-corner--bl {
  bottom: -1px;
  left: -1px;
  border-bottom-width: 2px;
  border-left-width: 2px;
}

.page-about .about-corner--br {
  bottom: -1px;
  right: -1px;
  border-bottom-width: 2px;
  border-right-width: 2px;
}

.page-about .crumbs {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 8px;
  margin: 0 0 40px;
  font-size: 12px;
  letter-spacing: .08em;
  color: var(--mist);
}

.page-about .crumbs a {
  color: var(--mist);
  text-decoration: none;
}

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

.page-about .crumbs__sep {
  color: var(--line);
}

.page-about .about-hero .eyebrow {
  margin: 0;
  font-size: 12px;
  letter-spacing: .22em;
  color: var(--cyan);
}

.page-about .about-hero h1 {
  margin: 18px 0 22px;
  max-width: 15em;
  font-size: clamp(34px, 6.6vw, 72px);
  font-weight: 900;
  line-height: 1.02;
  letter-spacing: -.03em;
}

.page-about .about-hero .lede {
  max-width: 34em;
  margin: 0;
  font-size: 17px;
  line-height: 1.78;
  color: rgba(244, 247, 246, .84);
}

.page-about .about-figures {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 22px 16px;
  margin-top: 40px;
  padding-top: 26px;
  border-top: 1px solid var(--line);
}

.page-about .about-figures__item {
  display: flex;
  flex-direction: column;
  gap: 6px;
}

.page-about .about-figures__num {
  font-family: var(--font-mono);
  font-size: 26px;
  letter-spacing: .04em;
  color: var(--cyan);
  line-height: 1;
}

.page-about .about-figures__label {
  font-size: 12px;
  letter-spacing: .06em;
  color: var(--mist);
}

/* ---------- 章节骨架 ---------- */
.page-about .about-section {
  padding: 76px var(--gutter);
}

.page-about .about-section--night {
  --about-node-bg: var(--night);
  background: var(--night);
}

.page-about .about-section--ink {
  background: linear-gradient(165deg, var(--wine) 0%, var(--indigo) 62%, var(--deep) 100%);
}

.page-about .about-section__inner {
  max-width: var(--maxw);
  margin: 0 auto;
}

.page-about .about-chapter {
  display: grid;
  gap: 16px;
}

.page-about .about-chapter__rail {
  display: flex;
  align-items: center;
  gap: 12px;
}

.page-about .about-chapter__num {
  font-family: var(--font-mono);
  font-size: 13px;
  letter-spacing: .2em;
  color: var(--cyan);
}

.page-about .about-chapter__note {
  font-size: 11px;
  letter-spacing: .16em;
  color: var(--mist);
}

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

.page-about .h-section {
  margin: 0 0 20px;
  font-size: clamp(26px, 4.4vw, 40px);
  font-weight: 800;
  line-height: 1.14;
  letter-spacing: -.02em;
}

.page-about .lede {
  margin: 0 0 18px;
  max-width: 34em;
  font-size: 17px;
  line-height: 1.78;
  color: rgba(244, 247, 246, .84);
}

.page-about .about-chapter__body p {
  max-width: 34em;
  font-size: 16px;
  line-height: 1.78;
  color: rgba(244, 247, 246, .8);
}

/* ---------- 媒体容器 ---------- */
.page-about .about-media {
  position: relative;
  margin: 0;
  border: 1px solid var(--line);
  background: var(--night);
  overflow: hidden;
  clip-path: polygon(0 0, 100% 0, 100% calc(100% - 26px), calc(100% - 26px) 100%, 0 100%);
}

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

.page-about .about-media--tall {
  aspect-ratio: 4 / 5;
}

.page-about .about-media--wide {
  aspect-ratio: 16 / 9;
}

.page-about .about-media__label {
  position: absolute;
  left: 0;
  bottom: 0;
  padding: 8px 14px;
  font-size: 11px;
  letter-spacing: .1em;
  color: var(--paper);
  background: rgba(7, 26, 43, .82);
  border-top: 1px solid var(--line);
  border-right: 1px solid var(--line);
}

/* ---------- 01 缘起 ---------- */
.page-about .about-origin {
  display: grid;
  gap: 28px;
}

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

/* ---------- 02 时间轴 ---------- */
.page-about .about-timeline__intro {
  display: grid;
  gap: 26px;
  margin-bottom: 12px;
}

.page-about .about-timeline {
  position: relative;
  list-style: none;
  margin: 36px 0 0;
  padding: 0;
}

.page-about .about-timeline::before {
  content: "";
  position: absolute;
  left: 12px;
  top: 10px;
  bottom: 20px;
  width: 2px;
  background: linear-gradient(180deg, var(--cyan) 0%, rgba(63, 224, 208, .25) 60%, var(--line) 100%);
}

.page-about .tl-node {
  position: relative;
  padding: 0 0 40px 42px;
}

.page-about .tl-node::before {
  content: "";
  position: absolute;
  left: 5px;
  top: 10px;
  width: 12px;
  height: 12px;
  border: 2px solid var(--cyan);
  border-radius: 50%;
  background: var(--about-node-bg);
}

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

.page-about .tl-node__year {
  margin: 0 0 8px;
  font-family: var(--font-mono);
  font-size: 38px;
  line-height: 1;
  letter-spacing: .02em;
  color: var(--paper);
}

.page-about .tl-node__content .h-card {
  margin: 0 0 10px;
  font-size: 19px;
  font-weight: 700;
  letter-spacing: -.01em;
}

.page-about .tl-node__content > p {
  margin: 0;
  max-width: 32em;
  font-size: 15.5px;
  line-height: 1.76;
  color: rgba(244, 247, 246, .78);
}

.page-about .tl-node__trigger,
.page-about .about-team__trigger {
  display: inline-flex;
  align-items: center;
  gap: 10px;
  margin-top: 16px;
  padding: 6px 0;
  border: 0;
  background: none;
  color: var(--cyan);
  font-family: var(--font-sans);
  font-size: 13px;
  letter-spacing: .08em;
  cursor: pointer;
}

.page-about .about-sign {
  position: relative;
  flex: 0 0 12px;
  width: 12px;
  height: 12px;
}

.page-about .about-sign::before,
.page-about .about-sign::after {
  content: "";
  position: absolute;
  left: 0;
  top: 50%;
  width: 12px;
  height: 2px;
  background: var(--cyan);
  transform: translateY(-50%);
}

.page-about .about-sign::after {
  transform: translateY(-50%) rotate(90deg);
  transition: transform .24s var(--ease), opacity .24s var(--ease);
}

.page-about .tl-node__trigger[aria-expanded="true"] .about-sign::after,
.page-about .about-team__trigger[aria-expanded="true"] .about-sign::after {
  transform: translateY(-50%) rotate(0deg);
  opacity: 0;
}

.page-about .tl-node__panel,
.page-about .about-team__panel {
  margin-top: 14px;
  padding: 16px 18px;
  border-left: 2px solid var(--cyan);
  background: rgba(7, 26, 43, .5);
}

.page-about .tl-node__panel p,
.page-about .about-team__panel p {
  margin: 0;
  max-width: 32em;
  font-size: 14.5px;
  line-height: 1.76;
  color: var(--mist);
}

/* ---------- 03 团队 ---------- */
.page-about .about-team__lead {
  display: grid;
  gap: 24px;
  margin-bottom: 34px;
}

.page-about .about-team {
  display: grid;
  gap: 20px;
}

.page-about .about-team__card {
  padding: 26px 22px 24px;
  border: 1px solid var(--line);
  background: linear-gradient(180deg, rgba(11, 42, 51, .9), rgba(7, 26, 43, .9));
  box-shadow: var(--shadow-card);
}

.page-about .about-team__count {
  margin: 0;
  font-family: var(--font-mono);
  font-size: 46px;
  line-height: 1;
  letter-spacing: .02em;
  color: var(--cyan);
}

.page-about .about-team__card .h-card {
  margin: 12px 0 10px;
  font-size: 18px;
  font-weight: 700;
}

.page-about .about-team__card > p {
  margin: 0;
  max-width: 26em;
  font-size: 15px;
  line-height: 1.74;
  color: rgba(244, 247, 246, .78);
}

/* ---------- 04 流程 ---------- */
.page-about .about-steps {
  list-style: none;
  margin: 34px 0 0;
  padding: 0;
  display: grid;
  gap: 26px;
  counter-reset: step;
}

.page-about .about-step {
  padding-top: 22px;
  border-top: 2px solid rgba(63, 224, 208, .5);
}

.page-about .about-step__num {
  display: block;
  font-family: var(--font-mono);
  font-size: 13px;
  letter-spacing: .2em;
  color: var(--cyan);
}

.page-about .about-step__title {
  margin: 10px 0 10px;
  font-size: 20px;
  font-weight: 700;
}

.page-about .about-step p {
  margin: 0;
  max-width: 30em;
  font-size: 15.5px;
  line-height: 1.76;
  color: rgba(244, 247, 246, .82);
}

.page-about .about-process__note {
  margin: 30px 0 0;
  padding-left: 14px;
  border-left: 2px solid var(--orange);
  font-size: 14.5px;
  line-height: 1.7;
  color: var(--paper);
  max-width: 34em;
}

/* ---------- 05 节奏 ---------- */
.page-about .about-rhythm {
  display: grid;
  gap: 16px;
  margin-top: 30px;
}

.page-about .about-rhythm__card {
  padding: 24px 20px;
  border: 1px solid var(--line);
  background: rgba(7, 26, 43, .72);
}

.page-about .about-rhythm__card:nth-child(2) {
  border-color: rgba(79, 208, 122, .4);
}

.page-about .about-rhythm__card:nth-child(3) {
  border-color: rgba(255, 122, 47, .4);
}

.page-about .about-rhythm__value {
  display: block;
  font-family: var(--font-mono);
  font-size: 30px;
  line-height: 1;
  letter-spacing: .03em;
  color: var(--cyan);
}

.page-about .about-rhythm__card:nth-child(2) .about-rhythm__value {
  color: var(--grass);
}

.page-about .about-rhythm__card:nth-child(3) .about-rhythm__value {
  color: var(--orange);
}

.page-about .about-rhythm__title {
  margin: 14px 0 8px;
  font-size: 17px;
  font-weight: 700;
}

.page-about .about-rhythm__card p {
  margin: 0;
  font-size: 14.5px;
  line-height: 1.74;
  color: var(--mist);
}

.page-about .about-rhythm__note {
  margin: 28px 0 0;
  max-width: 36em;
  font-size: 15.5px;
  line-height: 1.8;
  color: rgba(244, 247, 246, .8);
}

.page-about .about-rhythm__note a {
  color: var(--cyan);
  text-decoration: none;
  border-bottom: 1px solid rgba(63, 224, 208, .4);
}

.page-about .about-rhythm__note a:hover,
.page-about .about-rhythm__note a:focus-visible {
  border-bottom-color: var(--cyan);
}

/* ---------- 06 联系 ---------- */
.page-about .about-service {
  display: grid;
  gap: 30px;
  margin-top: 28px;
}

.page-about .about-service__row {
  display: flex;
  flex-wrap: wrap;
  align-items: baseline;
  gap: 6px 18px;
  padding: 14px 0;
  border-bottom: 1px solid var(--line);
}

.page-about .about-service__key {
  flex: 0 0 84px;
  font-size: 12px;
  letter-spacing: .12em;
  color: var(--mist);
}

.page-about .about-service__value {
  font-size: 16px;
  color: var(--paper);
  text-decoration: none;
  border-bottom: 1px solid transparent;
  word-break: break-all;
}

.page-about .about-service__value.mono {
  font-family: var(--font-mono);
  letter-spacing: .04em;
  color: var(--cyan);
}

.page-about .about-service a.about-service__value:hover,
.page-about .about-service a.about-service__value:focus-visible {
  border-bottom-color: var(--cyan);
}

.page-about .about-service__tip {
  margin: 18px 0 0;
  max-width: 34em;
  font-size: 14.5px;
  line-height: 1.76;
  color: var(--mist);
}

.page-about .about-service__aside {
  padding: 24px 20px;
  border: 1px solid var(--line);
  background: radial-gradient(120% 100% at 0% 0%, rgba(63, 224, 208, .14), transparent 62%), var(--night);
}

.page-about .about-service__aside-title {
  margin: 0 0 18px;
  font-size: 12px;
  letter-spacing: .2em;
  color: var(--cyan);
}

.page-about .about-service__btn {
  display: block;
  width: 100%;
  margin-bottom: 12px;
  text-align: center;
}

.page-about .about-service__aside-note {
  margin: 14px 0 0;
  font-size: 13.5px;
  line-height: 1.74;
  color: var(--mist);
}

.page-about .about-service__aside-note a {
  color: var(--cyan);
  text-decoration: none;
  border-bottom: 1px solid rgba(63, 224, 208, .4);
}

/* ---------- 断点 ---------- */
@media (min-width: 768px) {
  .page-about .about-section {
    padding: 104px var(--gutter);
  }

  .page-about .about-hero {
    padding-top: calc(var(--header-h) + 48px);
  }

  .page-about .about-frame {
    padding: 40px clamp(28px, 5vw, 72px) 64px;
  }

  .page-about .about-figures {
    grid-template-columns: repeat(4, minmax(0, 1fr));
    gap: 20px;
  }

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

  .page-about .about-origin {
    grid-template-columns: minmax(0, 4fr) minmax(0, 7fr);
    gap: 36px;
    align-items: start;
  }

  .page-about .about-timeline__intro {
    grid-template-columns: minmax(0, 6fr) minmax(0, 5fr);
    gap: 40px;
    align-items: center;
  }

  .page-about .about-team__lead {
    grid-template-columns: minmax(0, 5fr) minmax(0, 6fr);
    gap: 40px;
    align-items: center;
  }

  .page-about .about-team {
    grid-template-columns: repeat(3, minmax(0, 1fr));
    gap: 22px;
  }

  .page-about .about-steps {
    grid-template-columns: repeat(3, minmax(0, 1fr));
    gap: 30px;
  }

  .page-about .about-rhythm {
    grid-template-columns: repeat(3, minmax(0, 1fr));
    gap: 18px;
  }

  .page-about .about-service {
    grid-template-columns: minmax(0, 7fr) minmax(0, 4fr);
    gap: 40px;
    align-items: start;
  }
}

@media (min-width: 900px) {
  .page-about .about-chapter {
    grid-template-columns: var(--about-rail) minmax(0, 1fr);
    gap: 40px;
  }

  .page-about .about-chapter__rail {
    position: sticky;
    top: calc(var(--header-h-compact) + 40px);
    align-self: start;
    flex-direction: column;
    align-items: flex-start;
    gap: 16px;
  }

  .page-about .about-chapter__num {
    writing-mode: vertical-rl;
    font-size: 15px;
  }

  .page-about .about-chapter__note {
    writing-mode: vertical-rl;
    max-height: 240px;
    line-height: 1.5;
  }

  .page-about .about-timeline {
    margin-top: 48px;
  }

  .page-about .about-timeline::before {
    left: calc(var(--about-track-x) - 2px);
  }

  .page-about .tl-node {
    display: grid;
    grid-template-columns: calc(var(--about-track-x) - 56px) minmax(0, 1fr);
    gap: 56px;
    padding: 0 0 56px;
  }

  .page-about .tl-node::before {
    left: calc(var(--about-track-x) - 9px);
    top: 22px;
  }

  .page-about .tl-node__year {
    margin: 0;
    font-size: 72px;
    text-align: right;
    letter-spacing: -.01em;
    line-height: .92;
  }

  .page-about .tl-node__content {
    padding-top: 6px;
  }

  .page-about .about-team__card:nth-child(2) {
    margin-top: 30px;
  }

  .page-about .about-team__card:nth-child(3) {
    margin-top: 58px;
  }
}

@media (min-width: 1200px) {
  .page-about .about-index {
    display: block;
    position: fixed;
    right: 22px;
    top: 50%;
    transform: translateY(-50%);
    z-index: 5;
    padding-left: 14px;
    border-left: 1px solid var(--line);
  }
}

@media (prefers-reduced-motion: reduce) {
  .page-about .about-sign::after,
  .page-about .about-index__link {
    transition: none;
  }
}
<<<END>>>