.page-about {
  --about-rail: 96px;
  --about-gap: 40px;
}

/* ---------- 首屏 ---------- */
.page-about .about-hero {
  position: relative;
  padding-block: calc(var(--header-h) + 44px) 56px;
  background:
    radial-gradient(760px 380px at 84% -8%, rgba(27, 77, 99, .62), transparent 68%),
    radial-gradient(520px 320px at 2% 104%, rgba(14, 142, 118, .16), transparent 70%);
}

.page-about .about-hero::after {
  content: "";
  position: absolute;
  inset-inline: 0;
  inset-block-end: 0;
  height: 1px;
  background: linear-gradient(90deg, transparent, var(--accent-deep), transparent);
}

.page-about .about-hero__grid {
  display: grid;
  gap: 26px;
  margin-block-start: 32px;
}

.page-about .about-hero__rail {
  display: flex;
  align-items: center;
  gap: 14px;
  font-family: var(--font-mono);
}

.page-about .about-hero__mark {
  font-size: 12px;
  letter-spacing: .3em;
  color: var(--accent);
  text-transform: uppercase;
}

.page-about .about-hero__since {
  font-size: 12px;
  letter-spacing: .2em;
  color: var(--faint);
  padding-inline-start: 14px;
  border-inline-start: 1px solid var(--line);
}

.page-about .about-hero__title {
  font-family: var(--font-display);
  font-weight: 800;
  font-size: clamp(30px, 6vw, 58px);
  line-height: 1.16;
  letter-spacing: -.02em;
  color: var(--text);
  margin-block: 12px 20px;
  max-width: 18em;
}

.page-about .about-hero__lede {
  max-width: 60ch;
  color: var(--muted);
  font-size: 16px;
  line-height: 1.8;
}

.page-about .about-hero__stats {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 20px 16px;
  margin-block-start: 34px;
  padding-block-start: 26px;
  border-block-start: 1px solid var(--line);
}

.page-about .stat__num {
  display: block;
  font-family: var(--font-mono);
  font-variant-numeric: tabular-nums;
  font-size: 28px;
  font-weight: 700;
  line-height: 1.1;
  color: var(--accent);
  letter-spacing: -.01em;
}

.page-about .stat__label {
  display: block;
  margin-block-start: 8px;
  font-size: 13px;
  line-height: 1.5;
  color: var(--muted);
}

/* ---------- 章节骨架 ---------- */
.page-about .chapter {
  display: grid;
  gap: 18px;
  padding-block-start: 64px;
}

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

.page-about .chapter__num {
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: .18em;
  color: var(--faint);
  padding: 3px 10px;
  border: 1px solid var(--line);
  transition: color .35s var(--ease), border-color .35s var(--ease);
}

.page-about .chapter__note {
  font-size: 12px;
  letter-spacing: .22em;
  color: var(--faint);
  transition: color .35s var(--ease);
}

.page-about .chapter.is-visible .chapter__num {
  color: var(--accent);
  border-color: var(--accent-deep);
}

.page-about .chapter.is-visible .chapter__note {
  color: var(--muted);
}

.page-about .chapter__title {
  font-family: var(--font-display);
  font-weight: 800;
  font-size: clamp(23px, 3.4vw, 38px);
  line-height: 1.28;
  letter-spacing: -.01em;
  color: var(--text);
  margin-block: 0 18px;
  max-width: 20em;
}

.page-about .chapter__body p {
  font-size: 16px;
  line-height: 1.85;
  color: var(--muted);
  max-width: 66ch;
  margin-block: 0 16px;
}

.page-about .chapter__body h3 {
  color: var(--text);
}

/* ---------- 卡片 ---------- */
.page-about .card {
  position: relative;
  background: linear-gradient(180deg, rgba(14, 31, 48, .96), rgba(8, 19, 31, .96));
  border: 1px solid var(--line);
  border-block-start: 2px solid var(--accent-deep);
  padding: 20px 20px 18px;
  transition: border-color .3s var(--ease), transform .3s var(--ease);
}

.page-about .card:hover {
  border-color: var(--accent-deep);
  border-block-start-color: var(--accent);
}

.page-about .card__k {
  display: inline-block;
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: .16em;
  color: var(--accent);
  margin-block-end: 10px;
}

.page-about .card__t {
  font-size: 17px;
  font-weight: 700;
  line-height: 1.5;
  color: var(--text);
  margin-block: 0 10px;
}

.page-about .card p {
  font-size: 14.5px;
  line-height: 1.75;
  color: var(--muted);
  margin: 0;
}

.page-about .why-grid {
  display: grid;
  gap: 16px;
  margin-block-start: 28px;
}

/* ---------- 时间轴 ---------- */
.page-about .timeline-band {
  margin: 28px 0 0;
  position: relative;
  overflow: hidden;
  border-block: 1px solid var(--line);
}

.page-about .timeline-band img {
  display: block;
  width: 100%;
  height: auto;
  max-width: 100%;
  object-fit: cover;
  aspect-ratio: 16 / 6;
  opacity: .55;
  filter: saturate(.9);
}

.page-about .timeline-band::after {
  content: "";
  position: absolute;
  inset: 0;
  background: linear-gradient(90deg, rgba(8, 19, 31, .9), transparent 35%, transparent 65%, rgba(8, 19, 31, .9));
  pointer-events: none;
}

.page-about .timeline {
  list-style: none;
  margin: 34px 0 0;
  padding: 0 0 0 26px;
  position: relative;
}

.page-about .timeline::before {
  content: "";
  position: absolute;
  inset-block: 8px;
  inset-inline-start: 5px;
  width: 1px;
  background: linear-gradient(180deg, var(--accent-deep), var(--line) 45%, var(--line));
}

.page-about .timeline__item {
  position: relative;
  padding-block-end: 30px;
}

.page-about .timeline__item:last-child {
  padding-block-end: 0;
}

.page-about .timeline__item::before {
  content: "";
  position: absolute;
  inset-inline-start: -26px;
  inset-block-start: 8px;
  width: 9px;
  height: 9px;
  border-radius: 50%;
  background: var(--faint);
  box-shadow: 0 0 0 3px var(--ink);
  transition: background .45s var(--ease), box-shadow .45s var(--ease);
}

.page-about .timeline.is-visible .timeline__item::before {
  background: var(--accent);
  box-shadow: 0 0 0 3px var(--ink), 0 0 12px rgba(34, 240, 196, .5);
}

.page-about .timeline.is-visible .timeline__item:nth-child(2)::before { transition-delay: .12s; }
.page-about .timeline.is-visible .timeline__item:nth-child(3)::before { transition-delay: .24s; }
.page-about .timeline.is-visible .timeline__item:nth-child(4)::before { transition-delay: .36s; }
.page-about .timeline.is-visible .timeline__item:nth-child(5)::before { transition-delay: .48s; }

.page-about .timeline__date {
  display: block;
  font-family: var(--font-mono);
  font-variant-numeric: tabular-nums;
  font-size: 12.5px;
  letter-spacing: .12em;
  color: var(--accent);
  margin-block-end: 8px;
}

.page-about .timeline__title {
  font-size: 17px;
  font-weight: 700;
  line-height: 1.55;
  color: var(--text);
  margin-block: 0 8px;
}

.page-about .timeline__desc {
  font-size: 14.5px;
  line-height: 1.8;
  color: var(--muted);
  margin: 0;
  max-width: 62ch;
}

/* ---------- 编辑台 ---------- */
.page-about .desk-layout {
  display: grid;
  gap: 26px;
  margin-block-start: 30px;
}

.page-about .steps {
  list-style: none;
  margin: 0;
  padding: 0;
  counter-reset: step;
}

.page-about .steps__item {
  position: relative;
  padding: 18px 18px 18px 20px;
  margin-block-end: 14px;
  background: var(--ink-2);
  border-inline-start: 2px solid var(--line);
  transition: border-color .3s var(--ease), background .3s var(--ease);
}

.page-about .steps__item:hover {
  border-inline-start-color: var(--accent);
  background: rgba(23, 54, 79, .55);
}

.page-about .steps__num {
  display: inline-block;
  font-family: var(--font-mono);
  font-size: 11.5px;
  letter-spacing: .18em;
  color: var(--accent);
  margin-block-end: 8px;
}

.page-about .steps__title {
  font-size: 16px;
  font-weight: 700;
  line-height: 1.55;
  color: var(--text);
  margin-block: 0 8px;
}

.page-about .steps__item p {
  font-size: 14.5px;
  line-height: 1.78;
  color: var(--muted);
  margin: 0;
  max-width: none;
}

.page-about .desk-note {
  font-size: 14px;
  line-height: 1.8;
  color: var(--text);
  border-inline-start: 2px solid var(--alert);
  padding-inline-start: 14px;
  margin-block-start: 22px;
  max-width: 58ch;
}

.page-about .desk-figure {
  margin: 0;
}

.page-about .desk-figure img,
.page-about .team-figure img {
  display: block;
  width: 100%;
  max-width: 100%;
  height: auto;
  aspect-ratio: 3 / 2;
  object-fit: cover;
  filter: saturate(.85) contrast(1.05);
}

/* ---------- 团队 ---------- */
.page-about .team-layout {
  display: grid;
  gap: 26px;
  margin-block-start: 28px;
}

.page-about .team-bars {
  display: grid;
  gap: 16px;
  align-content: start;
}

.page-about .team-bars__row {
  display: grid;
  grid-template-columns: minmax(0, 1fr) auto;
  grid-template-areas:
    "label value"
    "track track";
  gap: 6px 10px;
  align-items: center;
}

.page-about .team-bars__label {
  grid-area: label;
  font-size: 14px;
  color: var(--text);
  line-height: 1.4;
}

.page-about .team-bars__value {
  grid-area: value;
  font-family: var(--font-mono);
  font-variant-numeric: tabular-nums;
  font-size: 17px;
  font-weight: 700;
  color: var(--accent);
}

.page-about .team-bars__track {
  grid-area: track;
  display: block;
  height: 6px;
  background: rgba(90, 115, 134, .22);
  overflow: hidden;
}

.page-about .team-bars__fill {
  display: block;
  height: 100%;
  width: 100%;
  transform: scaleX(1);
  transform-origin: left center;
  background: linear-gradient(90deg, var(--accent), var(--accent-deep));
}

.page-about .team-bars__row:nth-child(1) .team-bars__fill { width: 32.4%; }
.page-about .team-bars__row:nth-child(2) .team-bars__fill { width: 20.6%; }
.page-about .team-bars__row:nth-child(3) .team-bars__fill { width: 13.2%; }
.page-about .team-bars__row:nth-child(4) .team-bars__fill { width: 33.8%; }

@keyframes aboutBarGrow {
  from { transform: scaleX(0); }
  to { transform: scaleX(1); }
}

.page-about .team-bars.is-visible .team-bars__fill {
  animation: aboutBarGrow .85s var(--ease) both;
}

.page-about .team-bars.is-visible .team-bars__row:nth-child(2) .team-bars__fill { animation-delay: .1s; }
.page-about .team-bars.is-visible .team-bars__row:nth-child(3) .team-bars__fill { animation-delay: .2s; }
.page-about .team-bars.is-visible .team-bars__row:nth-child(4) .team-bars__fill { animation-delay: .3s; }

.page-about .team-figure {
  margin: 0;
}

.page-about .eco {
  margin-block-start: 30px;
  padding: 22px 20px;
  background: linear-gradient(120deg, rgba(27, 77, 99, .5), transparent 78%);
  border-inline-start: 2px solid var(--accent);
}

.page-about .eco__title {
  font-size: 17px;
  font-weight: 700;
  line-height: 1.55;
  color: var(--text);
  margin-block: 0 10px;
}

.page-about .eco p {
  font-size: 14.5px;
  line-height: 1.8;
  color: var(--muted);
  margin: 0;
  max-width: 66ch;
}

/* ---------- 承诺 ---------- */
.page-about .promise-grid {
  display: grid;
  gap: 16px;
  margin-block-start: 28px;
}

.page-about .card--promise .tag {
  display: inline-block;
  font-family: var(--font-mono);
  font-size: 11.5px;
  letter-spacing: .14em;
  color: var(--text);
  padding: 3px 9px;
  border: 1px solid var(--line);
  margin-block-end: 12px;
}

.page-about .card--promise .tag--live {
  color: var(--alert);
  border-color: rgba(255, 91, 51, .5);
}

/* ---------- 收尾 ---------- */
.page-about .about-cta {
  margin-block-start: 72px;
  padding-block: 44px 60px;
  border-block-start: 1px solid var(--line);
  background: radial-gradient(620px 260px at 20% 0%, rgba(27, 77, 99, .55), transparent 72%);
}

.page-about .about-cta__inner {
  display: grid;
  gap: 24px;
}

.page-about .about-cta__title {
  font-family: var(--font-display);
  font-weight: 800;
  font-size: clamp(22px, 3.2vw, 34px);
  line-height: 1.3;
  letter-spacing: -.01em;
  color: var(--text);
  margin-block: 0 12px;
}

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

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

/* ---------- 媒体查询 ---------- */
@media (min-width: 700px) {
  .page-about .why-grid {
    grid-template-columns: repeat(3, minmax(0, 1fr));
  }

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

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

@media (min-width: 900px) {
  .page-about .about-hero {
    padding-block: calc(var(--header-h) + 56px) 72px;
  }

  .page-about .about-hero__grid {
    grid-template-columns: 110px minmax(0, 1fr);
    gap: 52px;
    margin-block-start: 44px;
  }

  .page-about .about-hero__rail {
    flex-direction: column;
    align-items: flex-start;
    gap: 22px;
  }

  .page-about .about-hero__mark {
    writing-mode: vertical-rl;
    text-orientation: upright;
    letter-spacing: .22em;
  }

  .page-about .about-hero__since {
    writing-mode: vertical-rl;
    letter-spacing: .26em;
    padding-inline-start: 0;
    border-inline-start: 0;
    padding-block-start: 18px;
    border-block-start: 1px solid var(--line);
  }

  .page-about .chapter {
    grid-template-columns: var(--about-rail) minmax(0, 1fr);
    gap: var(--about-gap);
    padding-block-start: 84px;
  }

  .page-about .chapter__rail {
    flex-direction: column;
    align-items: flex-start;
    align-self: start;
    position: sticky;
    top: calc(var(--header-h) + 32px);
    gap: 16px;
  }

  .page-about .chapter__num {
    writing-mode: vertical-rl;
    text-orientation: upright;
    font-size: 15px;
    letter-spacing: .3em;
    padding: 0;
    border: 0;
    border-inline-start: 1px solid var(--line);
    padding-inline-start: 14px;
    transition: color .35s var(--ease), border-color .35s var(--ease);
  }

  .page-about .chapter.is-visible .chapter__num {
    border-inline-start-color: var(--accent);
  }

  .page-about .chapter__note {
    writing-mode: vertical-rl;
    letter-spacing: .3em;
  }

  .page-about .desk-layout {
    grid-template-columns: minmax(0, 1.08fr) minmax(0, .92fr);
    gap: 32px;
    align-items: start;
  }

  .page-about .team-layout {
    grid-template-columns: minmax(0, 1.05fr) minmax(0, .95fr);
    gap: 36px;
    align-items: start;
  }

  .page-about .about-cta__inner {
    grid-template-columns: minmax(0, 1fr) auto;
    align-items: end;
    gap: 32px;
  }

  .page-about .about-cta__actions {
    justify-content: flex-end;
  }
}
<<<END>>>