.page-about {
  --about-dash: rgba(55, 240, 192, .22);
  --about-tint: rgba(55, 240, 192, .05);
}

/* ---------- 首屏 ---------- */
.page-about .about-hero {
  position: relative;
  overflow: hidden;
  padding: clamp(20px, 4vw, 40px) 0 clamp(28px, 5vw, 60px);
  border-bottom: 1px solid var(--line);
  background:
    radial-gradient(120% 95% at 100% 0%, rgba(23, 69, 54, .85), rgba(8, 13, 11, 0) 62%),
    linear-gradient(180deg, var(--panel), var(--ink) 88%);
}

.page-about .about-hero::before {
  content: "";
  position: absolute;
  top: -30%;
  right: -22%;
  width: min(760px, 88%);
  height: 170%;
  background: linear-gradient(150deg, rgba(92, 32, 51, .55), rgba(46, 42, 99, .3) 52%, transparent 82%);
  transform: skewX(-16deg);
  pointer-events: none;
}

.page-about .about-hero::after {
  content: "";
  position: absolute;
  inset: 0;
  background-image:
    linear-gradient(to right, var(--about-tint) 1px, transparent 1px),
    linear-gradient(to bottom, var(--about-tint) 1px, transparent 1px);
  background-size: 64px 64px;
  mask-image: linear-gradient(120deg, rgba(0, 0, 0, .9), transparent 68%);
  -webkit-mask-image: linear-gradient(120deg, rgba(0, 0, 0, .9), transparent 68%);
  pointer-events: none;
}

.page-about .about-hero > .shell {
  position: relative;
  z-index: 1;
}

.page-about .breadcrumbs {
  margin-bottom: clamp(18px, 3vw, 32px);
}

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

.page-about .about-hero__text h1 {
  margin: 10px 0 16px;
  font-size: clamp(26px, 5.4vw, 48px);
  line-height: 1.16;
  letter-spacing: -.03em;
  color: var(--paper);
  max-width: 20ch;
}

.page-about .about-hero__text .lede {
  max-width: 62ch;
  color: var(--cyan-soft);
}

.page-about .about-hero__stamp {
  display: flex;
  align-items: baseline;
  gap: 10px;
  border-left: 2px solid var(--line-strong);
  padding-left: 14px;
}

.page-about .about-hero__stamp-num {
  font-family: var(--font-mono);
  font-size: clamp(56px, 13vw, 112px);
  line-height: .85;
  font-weight: 700;
  color: transparent;
  -webkit-text-stroke: 1.5px var(--cyan);
  letter-spacing: -.04em;
}

.page-about .about-hero__stamp-label {
  font-size: 12px;
  letter-spacing: .16em;
  color: var(--muted);
}

.page-about .about-stats {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 18px 20px;
  margin-top: clamp(24px, 4vw, 44px);
  padding-top: clamp(16px, 3vw, 26px);
  border-top: 1px dashed var(--about-dash);
}

.page-about .about-stats .stat__value {
  display: block;
  font-family: var(--font-mono);
  font-size: clamp(24px, 4vw, 36px);
  font-weight: 700;
  line-height: 1;
  color: var(--paper);
  letter-spacing: -.02em;
  font-variant-numeric: tabular-nums;
}

.page-about .about-stats .stat__label {
  display: block;
  margin-top: 6px;
  font-size: 12px;
  line-height: 1.5;
  letter-spacing: .06em;
  color: var(--muted);
}

/* ---------- 通用节点头 ---------- */
.page-about .section-head {
  display: grid;
  grid-template-columns: 1fr;
  gap: 8px;
  margin-bottom: clamp(18px, 3vw, 30px);
}

.page-about .section-num {
  font-family: var(--font-mono);
  font-size: clamp(40px, 8vw, 76px);
  line-height: .9;
  font-weight: 700;
  color: transparent;
  -webkit-text-stroke: 1.2px var(--line-strong);
  font-variant-numeric: tabular-nums;
}

.page-about .section-title {
  font-size: clamp(21px, 3.2vw, 30px);
  line-height: 1.24;
  letter-spacing: -.02em;
  color: var(--paper);
  margin: 0 0 10px;
  max-width: 26ch;
}

.page-about .section-head__text .lede {
  max-width: 64ch;
  color: var(--cyan-soft);
}

/* ---------- 01 版本脉络 ---------- */
.page-about .about-versions__figure {
  margin: 0 0 clamp(20px, 3vw, 32px);
}

.page-about .about-tl__list {
  display: flex;
  gap: 8px;
  overflow-x: auto;
  padding-bottom: 6px;
  scrollbar-width: thin;
}

.page-about .about-tl__tab {
  flex: 0 0 auto;
  display: flex;
  flex-direction: column;
  align-items: flex-start;
  gap: 4px;
  min-width: 132px;
  padding: 10px 14px;
  border: 1px solid var(--line);
  border-radius: var(--radius);
  background: rgba(12, 36, 28, .6);
  color: var(--cyan-soft);
  cursor: pointer;
  transition: background .18s var(--ease), border-color .18s var(--ease), color .18s var(--ease);
}

.page-about .about-tl__tab:hover,
.page-about .about-tl__tab:focus-visible {
  border-color: var(--line-strong);
  background: var(--moss);
}

.page-about .about-tl__tab[aria-selected="true"] {
  background: var(--moss);
  border-color: var(--cyan);
  color: var(--paper);
}

.page-about .about-tl__year {
  font-family: var(--font-mono);
  font-size: 18px;
  font-weight: 700;
  letter-spacing: -.02em;
  font-variant-numeric: tabular-nums;
}

.page-about .about-tl__name {
  font-size: 12px;
  letter-spacing: .08em;
  color: var(--muted);
}

.page-about .about-tl__tab[aria-selected="true"] .about-tl__name {
  color: var(--cyan);
}

.page-about .about-tl__panels {
  display: grid;
  gap: 12px;
  margin-top: 16px;
}

.page-about .about-tl__panel {
  display: grid;
  gap: 10px;
  padding: clamp(18px, 3vw, 28px);
  border: 1px solid var(--line);
  border-radius: var(--radius);
  background: linear-gradient(140deg, var(--glass), rgba(12, 36, 28, .3));
  box-shadow: var(--shadow);
}

.page-about .about-tl__panel-year {
  font-family: var(--font-mono);
  font-size: clamp(52px, 11vw, 96px);
  line-height: .82;
  font-weight: 700;
  color: transparent;
  -webkit-text-stroke: 1.5px rgba(55, 240, 192, .5);
  font-variant-numeric: tabular-nums;
  letter-spacing: -.05em;
}

.page-about .about-tl__panel-body h3 {
  margin: 0 0 8px;
  font-size: clamp(17px, 2.2vw, 20px);
  line-height: 1.35;
  color: var(--paper);
}

.page-about .about-tl__panel-body p {
  margin: 0 0 10px;
  color: var(--cyan-soft);
  max-width: 66ch;
}

.page-about .about-tl__tags {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
  margin-top: 4px;
}

/* ---------- 02 流程 ---------- */
.page-about .about-flow__figure {
  margin: 0 0 clamp(20px, 3vw, 30px);
}

.page-about .about-flow__grid {
  display: grid;
  gap: 12px;
}

.page-about .flow-step {
  position: relative;
  padding: 18px 16px 20px;
  border: 1px solid var(--line);
  border-top: 3px solid var(--moss);
  border-radius: var(--radius);
  background: rgba(12, 36, 28, .72);
  transition: border-top-color .2s var(--ease), background .2s var(--ease);
}

.page-about .flow-step:hover,
.page-about .flow-step:focus-within {
  border-top-color: var(--cyan);
  background: rgba(23, 69, 54, .8);
}

.page-about .flow-step__time {
  display: inline-block;
  margin: 0 0 10px;
  padding: 3px 8px;
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: .06em;
  color: var(--ink);
  background: var(--signal);
  border-radius: 2px;
  font-variant-numeric: tabular-nums;
}

.page-about .flow-step__title {
  margin: 0 0 8px;
  font-size: 16px;
  line-height: 1.35;
  color: var(--paper);
}

.page-about .flow-step__desc {
  margin: 0;
  font-size: 14px;
  line-height: 1.68;
  color: var(--cyan-soft);
}

/* ---------- 03 团队 ---------- */
.page-about .about-crew__grid {
  display: grid;
  gap: clamp(20px, 3vw, 32px);
}

.page-about .about-crew__list {
  display: grid;
  gap: 12px;
}

.page-about .crew {
  display: grid;
  grid-template-columns: 40px minmax(0, 1fr);
  gap: 12px;
  padding: 16px;
  border-left: 2px solid var(--line-strong);
  background: linear-gradient(90deg, rgba(23, 69, 54, .55), rgba(12, 36, 28, .12));
  transition: background .2s var(--ease), border-left-color .2s var(--ease);
}

.page-about .crew:hover,
.page-about .crew:focus-visible {
  outline: none;
  border-left-color: var(--cyan);
  background: linear-gradient(90deg, rgba(23, 69, 54, .9), rgba(55, 240, 192, .08));
}

.page-about .crew:focus-visible {
  box-shadow: 0 0 0 2px var(--cyan) inset;
}

.page-about .crew__key {
  display: flex;
  align-items: center;
  justify-content: center;
  width: 40px;
  height: 40px;
  font-family: var(--font-mono);
  font-size: 15px;
  font-weight: 700;
  color: var(--cyan);
  border: 1px solid var(--line-strong);
  border-radius: 2px;
  background: rgba(8, 13, 11, .6);
}

.page-about .crew__title {
  display: flex;
  flex-wrap: wrap;
  align-items: baseline;
  gap: 10px;
  margin: 0 0 8px;
  font-size: 17px;
  color: var(--paper);
}

.page-about .crew__count {
  font-family: var(--font-mono);
  font-size: 12px;
  font-weight: 500;
  letter-spacing: .06em;
  color: var(--signal);
  border: 1px solid rgba(255, 138, 61, .45);
  border-radius: 2px;
  padding: 1px 6px;
  font-variant-numeric: tabular-nums;
}

.page-about .crew__body p {
  margin: 0;
  font-size: 14px;
  line-height: 1.7;
  color: var(--cyan-soft);
}

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

/* ---------- 04 协作网络 ---------- */
.page-about .about-network__grid {
  display: grid;
  gap: 14px;
}

.page-about .network-card {
  padding: clamp(20px, 3vw, 30px);
  border-radius: var(--radius);
  color: var(--paper);
  box-shadow: var(--shadow);
}

.page-about .network-card--wine {
  background: linear-gradient(155deg, var(--wine), #2a0e18 88%);
}

.page-about .network-card--indigo {
  background: linear-gradient(155deg, var(--indigo), #14122e 88%);
}

.page-about .network-card .eyebrow {
  color: rgba(247, 242, 231, .72);
}

.page-about .network-card__title {
  margin: 6px 0 10px;
  font-size: clamp(18px, 2.4vw, 23px);
  line-height: 1.3;
  color: var(--paper);
}

.page-about .network-card p {
  margin: 0 0 12px;
  font-size: 14px;
  line-height: 1.72;
  color: rgba(247, 242, 231, .88);
}

.page-about .network-card__meta {
  margin: 0;
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: .06em;
  color: var(--cyan-soft);
  border-top: 1px dashed rgba(247, 242, 231, .28);
  padding-top: 10px;
  font-variant-numeric: tabular-nums;
}

/* ---------- 05 访问方式 ---------- */
.page-about .about-reach__grid {
  display: grid;
  gap: 12px;
}

.page-about .reach-card {
  padding: 20px;
  border: 1px solid var(--line);
  border-radius: var(--radius);
  background: rgba(12, 36, 28, .62);
}

.page-about .reach-card .eyebrow {
  color: var(--muted);
}

.page-about .reach-card h3 {
  margin: 6px 0 10px;
  font-size: 17px;
  line-height: 1.35;
  color: var(--paper);
}

.page-about .reach-card p {
  margin: 0 0 12px;
  font-size: 14px;
  line-height: 1.7;
  color: var(--cyan-soft);
}

.page-about .reach-card__link {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
}

.page-about .about-reach__note {
  margin-top: 16px;
  padding: 16px 18px;
  border-left: 2px solid var(--signal);
  background: rgba(23, 69, 54, .38);
}

.page-about .about-reach__note p {
  margin: 0;
  font-size: 14px;
  line-height: 1.75;
  color: var(--cyan-soft);
  max-width: 68ch;
}

/* ---------- 06 回访 ---------- */
.page-about .about-return__grid {
  display: grid;
  gap: 12px;
}

.page-about .return-item {
  padding: 18px;
  border: 1px dashed var(--about-dash);
  border-radius: var(--radius);
  background: rgba(8, 13, 11, .55);
}

.page-about .return-item h3 {
  margin: 0 0 8px;
  font-size: 16px;
  color: var(--cyan);
}

.page-about .return-item p {
  margin: 0;
  font-size: 14px;
  line-height: 1.7;
  color: var(--cyan-soft);
}

.page-about .about-return__actions {
  margin-top: clamp(18px, 3vw, 28px);
}

/* ---------- 响应式 ---------- */
@media (min-width: 640px) {
  .page-about .about-hero__grid {
    grid-template-columns: minmax(0, 1fr) auto;
    align-items: end;
    gap: 28px;
  }

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

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

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

@media (min-width: 900px) {
  .page-about .section-head {
    grid-template-columns: 130px minmax(0, 1fr);
    gap: 24px;
    align-items: start;
  }

  .page-about .about-tl__list {
    display: grid;
    grid-template-columns: repeat(5, minmax(0, 1fr));
    overflow: visible;
  }

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

  .page-about .about-tl__panel {
    grid-template-columns: 180px minmax(0, 1fr);
    align-items: start;
    gap: 22px;
  }

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

  .page-about .about-flow__grid > *:nth-child(2) {
    margin-top: 18px;
  }

  .page-about .about-flow__grid > *:nth-child(3) {
    margin-top: 36px;
  }

  .page-about .about-flow__grid > *:nth-child(4) {
    margin-top: 54px;
  }

  .page-about .about-crew__grid {
    grid-template-columns: minmax(0, 1.2fr) minmax(0, .8fr);
    align-items: start;
  }

  .page-about .about-reach__grid {
    grid-template-columns: minmax(0, .9fr) minmax(0, 1.1fr);
  }

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

@media (min-width: 1100px) {
  .page-about .about-hero__text h1 {
    max-width: 18ch;
  }

  .page-about .about-tl__panel-year {
    font-size: 88px;
  }
}

@media (prefers-reduced-motion: reduce) {
  .page-about .about-tl__tab,
  .page-about .flow-step,
  .page-about .crew {
    transition: none;
  }
}