.page-about {
  --about-rail-w: minmax(0, 3fr);
  padding-bottom: clamp(64px, 9vw, 132px);
}

.page-about .about-layout {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: clamp(28px, 5vw, 52px);
  margin-top: clamp(20px, 3.6vw, 40px);
}

/* ---------- 左侧章节索引 ---------- */
.page-about .about-rail {
  min-width: 0;
}

.page-about .about-rail__label {
  margin: 0 0 14px;
  font-size: 12px;
  letter-spacing: .18em;
  text-transform: uppercase;
  color: var(--gold);
}

.page-about .about-rail__list {
  list-style: none;
  margin: 0;
  padding: 0 0 6px;
  display: flex;
  gap: 10px;
  overflow-x: auto;
  scroll-snap-type: x proximity;
  -webkit-overflow-scrolling: touch;
}

.page-about .about-rail__item {
  flex: 0 0 auto;
  scroll-snap-align: start;
}

.page-about .about-rail__link {
  display: inline-flex;
  align-items: baseline;
  gap: 8px;
  padding: 8px 12px;
  border: 1px solid var(--line);
  color: var(--paper-80);
  font-size: 14px;
  text-decoration: none;
  white-space: nowrap;
  transition: border-color var(--dur) var(--ease), color var(--dur) var(--ease), transform var(--dur) var(--ease);
}

.page-about .about-rail__link:hover,
.page-about .about-rail__link:focus-visible {
  border-color: var(--gold);
  color: var(--paper);
  transform: translateY(-2px);
}

.page-about .about-rail__num {
  font-family: var(--font-mono);
  font-size: 12px;
  font-weight: 700;
  letter-spacing: .08em;
  color: var(--gold);
}

.page-about .about-rail__gloss {
  margin-top: 22px;
  padding-top: 16px;
  border-top: 1px solid var(--line);
}

.page-about .about-rail__gloss-label {
  margin: 0 0 10px;
  font-size: 12px;
  letter-spacing: .18em;
  text-transform: uppercase;
  color: var(--slate);
}

.page-about .about-term {
  position: relative;
  display: inline-block;
  margin: 0 0 10px;
  padding-bottom: 2px;
  border-bottom: 1px dashed var(--line-strong);
  color: var(--paper-80);
  font-size: 14px;
  cursor: help;
}

.page-about .about-term:focus-visible {
  outline: 2px solid var(--gold);
  outline-offset: 3px;
}

.page-about .about-term__pop {
  position: absolute;
  left: 0;
  bottom: calc(100% + 10px);
  width: min(250px, 62vw);
  padding: 12px 14px;
  background: var(--ink-700);
  border: 1px solid var(--gold);
  color: var(--paper-80);
  font-size: 13px;
  line-height: 1.7;
  opacity: 0;
  visibility: hidden;
  transform: translateY(4px);
  transition: opacity var(--dur) var(--ease), transform var(--dur) var(--ease), visibility var(--dur) var(--ease);
  z-index: 10;
}

.page-about .about-term:hover .about-term__pop,
.page-about .about-term:focus .about-term__pop {
  opacity: 1;
  visibility: visible;
  transform: translateY(0);
}

/* ---------- 首屏 ---------- */
.page-about .about-intro {
  position: relative;
  padding-bottom: clamp(34px, 5vw, 60px);
  border-bottom: 1px solid var(--line-strong);
}

.page-about .about-intro::before {
  content: "";
  position: absolute;
  inset: -30px -6% auto -6%;
  height: 300px;
  background:
    radial-gradient(58% 100% at 18% 0%, rgba(41, 211, 194, .10), transparent 70%),
    radial-gradient(46% 90% at 84% 0%, rgba(217, 164, 65, .14), transparent 72%);
  pointer-events: none;
}

.page-about .about-intro__title {
  position: relative;
  margin: 16px 0 clamp(18px, 2.6vw, 28px);
  max-width: 18ch;
  font-family: var(--font-display);
  font-size: clamp(34px, 6.6vw, 74px);
  font-weight: 800;
  line-height: 1.06;
  letter-spacing: -.02em;
  color: var(--paper);
}

.page-about .about-intro__lede {
  position: relative;
  margin: 0;
  max-width: 62ch;
  font-size: clamp(16px, 1.6vw, 17px);
  line-height: 1.8;
  color: var(--paper-80);
}

.page-about .about-facts {
  position: relative;
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(150px, 1fr));
  gap: 1px;
  margin: clamp(28px, 4vw, 44px) 0 0;
  padding: 0;
  background: var(--line);
  border: 1px solid var(--line);
}

.page-about .about-fact {
  margin: 0;
  padding: 16px 18px;
  background: var(--ink-800);
}

.page-about .about-fact__key {
  margin: 0 0 8px;
  font-size: 12px;
  letter-spacing: .14em;
  color: var(--slate);
}

.page-about .about-fact__val {
  margin: 0;
  font-size: 15px;
  color: var(--paper);
}

.page-about .about-fact__num {
  font-family: var(--font-mono);
  font-size: 22px;
  font-weight: 700;
  letter-spacing: .08em;
  color: var(--gold);
}

/* ---------- 通用区块 ---------- */
.page-about .about-section {
  padding-top: clamp(46px, 6.4vw, 88px);
  border-top: 1px solid var(--line);
}

.page-about .about-body > .about-section:first-of-type {
  border-top: 0;
  padding-top: clamp(34px, 5vw, 64px);
}

.page-about .about-section__head {
  margin-bottom: clamp(24px, 3.4vw, 40px);
}

.page-about .about-section__title {
  margin: 14px 0 0;
  max-width: 22ch;
  font-family: var(--font-display);
  font-size: clamp(26px, 3.8vw, 44px);
  font-weight: 800;
  line-height: 1.14;
  letter-spacing: -.015em;
  color: var(--paper);
}

.page-about .about-section__note {
  margin: 16px 0 0;
  max-width: 58ch;
  font-size: 15px;
  line-height: 1.8;
  color: var(--slate);
}

.page-about .about-section__grid {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: clamp(22px, 3vw, 40px);
}

.page-about .about-section__aside {
  padding-left: 16px;
  border-left: 2px solid var(--gold);
}

.page-about .about-note__label {
  margin: 0 0 8px;
  font-size: 12px;
  letter-spacing: .18em;
  text-transform: uppercase;
  color: var(--gold);
}

.page-about .about-note {
  margin: 0;
  font-size: 14px;
  line-height: 1.8;
  color: var(--paper-62);
}

.page-about .about-figure {
  margin: clamp(28px, 4vw, 44px) 0 0;
}

.page-about .about-figure .media-frame__img {
  display: block;
  width: 100%;
  max-width: 100%;
  height: auto;
  object-fit: cover;
}

/* ---------- 数据流程 ---------- */
.page-about .about-flow {
  list-style: none;
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 1px;
  margin: clamp(26px, 3.6vw, 40px) 0 0;
  padding: 0;
  background: var(--line);
  border: 1px solid var(--line);
}

.page-about .about-flow__step {
  position: relative;
  padding: clamp(20px, 2.6vw, 30px);
  background: var(--ink-800);
}

.page-about .about-flow__num {
  display: block;
  font-family: var(--font-mono);
  font-size: 13px;
  font-weight: 700;
  letter-spacing: .18em;
  color: var(--gold);
}

.page-about .about-flow__title {
  margin: 12px 0 10px;
  font-size: 18px;
  font-weight: 700;
  color: var(--paper);
}

.page-about .about-flow__text {
  margin: 0;
  font-size: 15px;
  line-height: 1.8;
  color: var(--paper-62);
}

.page-about .about-versions {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: clamp(14px, 2vw, 22px);
  margin-top: clamp(22px, 3vw, 34px);
}

.page-about .about-version {
  padding: clamp(18px, 2.4vw, 28px);
  border: 1px solid var(--line);
  border-left-width: 3px;
  background: linear-gradient(180deg, rgba(27, 42, 74, .9), rgba(16, 26, 51, .62));
}

.page-about .about-version--a {
  border-left-color: var(--cyan);
}

.page-about .about-version--b {
  border-left-color: var(--orange);
}

.page-about .about-version__time {
  margin: 16px 0 10px;
  font-size: 14px;
  letter-spacing: .06em;
  color: var(--paper-80);
}

.page-about .about-version__num {
  font-family: var(--font-mono);
  font-size: clamp(30px, 4.2vw, 44px);
  font-weight: 700;
  letter-spacing: .08em;
}

.page-about .about-version__num--a {
  color: var(--cyan);
}

.page-about .about-version__num--b {
  color: var(--orange);
}

.page-about .about-version__text {
  margin: 0;
  font-size: 15px;
  line-height: 1.8;
  color: var(--paper-62);
}

/* ---------- 团队构成 ---------- */
.page-about .about-bars {
  display: grid;
  gap: clamp(16px, 2.2vw, 22px);
  margin-bottom: clamp(28px, 4vw, 44px);
}

.page-about .about-bar__head {
  display: flex;
  align-items: baseline;
  justify-content: space-between;
  gap: 16px;
  margin-bottom: 8px;
}

.page-about .about-bar__name {
  font-size: 14px;
  color: var(--paper-80);
}

.page-about .about-bar__val {
  font-family: var(--font-mono);
  font-size: 15px;
  font-weight: 700;
  letter-spacing: .08em;
  color: var(--paper);
}

.page-about .about-bar__track {
  height: 10px;
  background: rgba(124, 138, 165, .14);
  border: 1px solid var(--line);
}

.page-about .about-bar__fill {
  display: block;
  height: 100%;
}

.page-about .about-bar__fill--gold {
  width: 100%;
  background: linear-gradient(90deg, var(--gold), var(--gold-soft));
}

.page-about .about-bar__fill--cyan {
  width: 18%;
  background: var(--cyan);
}

.page-about .about-bar__fill--orange {
  width: 9%;
  background: var(--orange);
}

/* ---------- 时间线 ---------- */
.page-about .about-timeline {
  position: relative;
  list-style: none;
  margin: 0;
  padding: 0;
}

.page-about .about-timeline::before {
  content: "";
  position: absolute;
  left: 11px;
  top: 10px;
  bottom: 10px;
  width: 1px;
  background: linear-gradient(180deg, rgba(217, 164, 65, 0), rgba(217, 164, 65, .55) 10%, rgba(217, 164, 65, .55) 90%, rgba(217, 164, 65, 0));
}

.page-about .about-tl {
  position: relative;
  padding: 0 0 clamp(26px, 3.4vw, 40px) 42px;
}

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

.page-about .about-tl:focus-visible {
  outline: 2px solid var(--gold);
  outline-offset: 4px;
}

.page-about .about-tl__dot {
  position: absolute;
  left: 0;
  top: 2px;
  display: grid;
  place-items: center;
  width: 24px;
  height: 24px;
  background: var(--ink-900);
}

.page-about .about-tl__stage {
  margin: 0 0 6px;
  font-family: var(--font-mono);
  font-size: 12px;
  font-weight: 700;
  letter-spacing: .18em;
  color: var(--gold);
}

.page-about .about-tl__title {
  margin: 0 0 8px;
  font-size: clamp(18px, 2vw, 21px);
  font-weight: 700;
  color: var(--paper);
}

.page-about .about-tl__text {
  margin: 0;
  max-width: 62ch;
  font-size: 15px;
  line-height: 1.8;
  color: var(--paper-62);
}

.page-about .about-tl__detail {
  max-height: 0;
  margin-top: 0;
  overflow: hidden;
  font-size: 14px;
  line-height: 1.8;
  color: var(--slate);
  opacity: 0;
  transition: max-height var(--dur) var(--ease), opacity var(--dur) var(--ease), margin-top var(--dur) var(--ease);
}

.page-about .about-tl:hover .about-tl__detail,
.page-about .about-tl:focus-within .about-tl__detail,
.page-about .about-tl:focus .about-tl__detail {
  max-height: 140px;
  margin-top: 10px;
  opacity: 1;
}

/* ---------- 备案与反馈 ---------- */
.page-about .about-trust {
  margin: 0;
  border-top: 1px solid var(--line);
}

.page-about .about-trust__row {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 4px;
  padding: 16px 0;
  border-bottom: 1px solid var(--line);
}

.page-about .about-trust__key {
  margin: 0;
  font-size: 12px;
  letter-spacing: .16em;
  color: var(--slate);
}

.page-about .about-trust__val {
  margin: 0;
  font-size: 16px;
  color: var(--paper);
}

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

.page-about .about-trust__num {
  font-family: var(--font-mono);
  font-size: 20px;
  font-weight: 700;
  letter-spacing: .08em;
  color: var(--gold);
}

.page-about .about-closing {
  margin-top: clamp(24px, 3.2vw, 36px);
  max-width: 68ch;
}

.page-about .about-closing p {
  margin: 0 0 16px;
  font-size: 15px;
  line-height: 1.85;
  color: var(--paper-80);
}

.page-about .about-link {
  color: var(--gold);
  text-decoration: none;
  border-bottom: 1px solid var(--gold);
}

.page-about .about-link:hover,
.page-about .about-link:focus-visible {
  color: var(--gold-soft);
  border-bottom-color: var(--gold-soft);
}

/* ---------- 响应式 ---------- */
@media (min-width: 768px) {
  .page-about .about-section__grid {
    grid-template-columns: minmax(0, 1fr) 250px;
    align-items: start;
  }

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

  .page-about .about-flow__step::after {
    content: "";
    position: absolute;
    right: -7px;
    top: 34px;
    width: 13px;
    height: 1px;
    background: var(--gold);
    z-index: 2;
  }

  .page-about .about-flow__step:last-child::after {
    display: none;
  }

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

  .page-about .about-trust__row {
    grid-template-columns: 200px minmax(0, 1fr);
    align-items: baseline;
    gap: 20px;
  }
}

@media (min-width: 1024px) {
  .page-about .about-layout {
    grid-template-columns: minmax(0, 3fr) minmax(24px, 1fr) minmax(0, 8fr);
    column-gap: clamp(30px, 4vw, 60px);
    align-items: start;
  }

  .page-about .about-rail {
    grid-column: 1;
    position: sticky;
    top: 104px;
    align-self: start;
  }

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

  .page-about .about-rail__item + .about-rail__item {
    margin-top: 4px;
  }

  .page-about .about-rail__link {
    display: flex;
    width: 100%;
    padding: 9px 10px;
    border-color: transparent;
    border-left: 2px solid var(--line);
  }

  .page-about .about-rail__link:hover,
  .page-about .about-rail__link:focus-visible {
    border-left-color: var(--gold);
    background: rgba(217, 164, 65, .06);
  }

  .page-about .about-body {
    grid-column: 3;
    min-width: 0;
  }

  .page-about .about-section__grid--team {
    grid-template-columns: minmax(0, 1fr) 230px;
  }
}

@media (hover: none) {
  .page-about .about-tl__detail {
    max-height: none;
    margin-top: 10px;
    opacity: 1;
  }

  .page-about .about-term__pop {
    position: static;
    display: block;
    width: auto;
    margin-top: 10px;
    opacity: 1;
    visibility: visible;
    transform: none;
  }
}

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

  .page-about .about-rail__link:hover,
  .page-about .about-rail__link:focus-visible {
    transform: none;
  }
}
<<<END>>>