.page-about .about-intro {
  position: relative;
  overflow: hidden;
  background: var(--ink);
  color: var(--cream);
  padding-top: clamp(18px, 3vw, 30px);
  padding-bottom: clamp(32px, 5vw, 56px);
}

.page-about .about-intro::before {
  content: "";
  position: absolute;
  inset: 0;
  background-image: linear-gradient(to right, var(--line-light) 1px, transparent 1px);
  background-size: calc(100% / 5) 100%;
  opacity: .55;
  pointer-events: none;
}

.page-about .about-intro > * {
  position: relative;
  z-index: 1;
}

.page-about .about-intro .breadcrumb {
  margin-bottom: clamp(20px, 4vw, 40px);
}

.page-about .about-intro .breadcrumb__list {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
  list-style: none;
  margin: 0;
  padding: 0;
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: .02em;
  color: rgba(244, 241, 234, .58);
}

.page-about .about-intro .breadcrumb__item + .breadcrumb__item::before {
  content: "/";
  margin-right: 8px;
  color: rgba(244, 241, 234, .35);
}

.page-about .about-intro .breadcrumb a {
  color: rgba(244, 241, 234, .78);
  text-decoration: none;
  border-bottom: 1px solid transparent;
}

.page-about .about-intro .breadcrumb a:hover,
.page-about .about-intro .breadcrumb a:focus-visible {
  color: var(--cream);
  border-bottom-color: var(--signal);
}

.page-about .about-intro__title {
  max-width: 18ch;
  margin: 0 0 clamp(16px, 2.6vw, 24px);
  font-size: clamp(32px, 6.4vw, 74px);
  font-weight: 900;
  line-height: 1.02;
  letter-spacing: -.02em;
  color: var(--paper);
}

.page-about .about-intro__lede {
  max-width: 60ch;
  margin: 0 0 clamp(26px, 4vw, 44px);
  font-size: clamp(15px, 1.6vw, 18px);
  line-height: 1.8;
  color: rgba(244, 241, 234, .82);
}

.page-about .about-intro__facts {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 1px;
  margin: 0;
  padding: 0;
  list-style: none;
  background: var(--line-light);
  border-top: 1px solid var(--line-light);
  border-bottom: 1px solid var(--line-light);
}

.page-about .about-fact {
  display: flex;
  flex-direction: column;
  gap: 4px;
  padding: 16px 14px;
  background: var(--ink);
}

.page-about .about-fact__num {
  font-size: clamp(24px, 3.4vw, 34px);
  font-weight: 700;
  line-height: 1;
  color: var(--cream);
}

.page-about .about-fact__label {
  font-size: 12.5px;
  line-height: 1.6;
  color: rgba(244, 241, 234, .62);
}

.page-about .about-intro__figure {
  margin: clamp(28px, 4vw, 48px) 0 0;
}

.page-about .about-intro__figure .figure__frame {
  aspect-ratio: 3 / 2;
  border: 1px solid var(--line-light);
  overflow: hidden;
}

.page-about .about-intro__figure img {
  display: block;
  width: 100%;
  height: 100%;
  max-width: 100%;
  object-fit: cover;
  filter: saturate(.85);
}

.page-about .about-intro__figure .figure__caption {
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: .02em;
  color: rgba(244, 241, 234, .55);
}

.page-about .about-sec-head {
  max-width: 66ch;
  margin-bottom: clamp(24px, 4vw, 44px);
}

.page-about .about-sec-head--tight {
  margin-bottom: clamp(20px, 3vw, 32px);
}

.page-about .about-sec-head h2 {
  margin: 10px 0 12px;
  font-size: clamp(24px, 3.8vw, 42px);
  font-weight: 800;
  line-height: 1.12;
  letter-spacing: -.015em;
  color: var(--ink);
}

.page-about .about-sec-head__lead {
  margin: 0;
  font-size: 15px;
  line-height: 1.9;
  color: var(--slate);
}

.page-about .about-sec-head .eyebrow {
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: .06em;
  text-transform: uppercase;
  color: var(--celadon);
}

/* 01 服务对象 */
.page-about .about-who {
  background: var(--cream);
}

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

.page-about .about-who__card {
  padding: clamp(20px, 3vw, 30px);
  border: 1px solid var(--line-ink);
  background: var(--paper);
}

.page-about .about-who__card--accent {
  border-left: 3px solid var(--signal);
}

.page-about .about-who__card h3 {
  margin: 14px 0 10px;
  font-size: clamp(18px, 2.2vw, 22px);
  line-height: 1.35;
  color: var(--ink);
}

.page-about .about-who__card p {
  margin: 0 0 14px;
  font-size: 14.5px;
  line-height: 1.9;
  color: var(--text);
}

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

.page-about .about-who__list li {
  position: relative;
  padding: 10px 0 10px 18px;
  font-size: 13.5px;
  line-height: 1.75;
  color: var(--slate);
  border-bottom: 1px solid var(--line-ink);
}

.page-about .about-who__list li::before {
  content: "";
  position: absolute;
  left: 0;
  top: 18px;
  width: 6px;
  height: 6px;
  background: var(--celadon);
}

/* 02 版本演进 */
.page-about .about-versions {
  background: var(--paper);
  border-top: 1px solid var(--line-ink);
  border-bottom: 1px solid var(--line-ink);
}

.page-about .about-versions__body {
  display: grid;
  gap: clamp(26px, 4vw, 44px);
}

.page-about .vtrack {
  margin: 0;
  padding: 0;
  list-style: none;
}

.page-about .vtrack__item {
  position: relative;
  padding: 0 0 14px 26px;
}

.page-about .vtrack__item::before {
  content: "";
  position: absolute;
  left: 5px;
  top: 16px;
  bottom: 0;
  width: 1px;
  background: var(--line-ink-strong);
}

.page-about .vtrack__item:last-child::before {
  display: none;
}

.page-about .vtrack__dot {
  position: absolute;
  left: 0;
  top: 7px;
  width: 11px;
  height: 11px;
  border: 1px solid var(--slate);
  background: var(--paper);
}

.page-about .vtrack__item--current .vtrack__dot {
  background: var(--signal);
  border-color: var(--signal);
}

.page-about .vnode > summary {
  display: flex;
  flex-wrap: wrap;
  align-items: baseline;
  gap: 6px 10px;
  padding: 0 0 6px;
  list-style: none;
  cursor: pointer;
}

.page-about .vnode > summary::-webkit-details-marker {
  display: none;
}

.page-about .vnode > summary:focus-visible {
  outline: 2px solid var(--signal);
  outline-offset: 3px;
}

.page-about .vnode__ver {
  font-size: 17px;
  font-weight: 700;
  letter-spacing: .02em;
  color: var(--ink);
  padding: 1px 5px;
  background: transparent;
}

.page-about .vtrack__item--current .vnode__ver {
  background: var(--signal);
  color: var(--ink-deep);
}

.page-about .vnode__time {
  font-family: var(--font-mono);
  font-size: 11.5px;
  letter-spacing: .04em;
  color: var(--mist);
}

.page-about .vnode__body {
  margin: 0 0 6px;
  padding: 8px 0 8px 12px;
  border-left: 1px solid var(--line-ink-strong);
  font-size: 13.5px;
  line-height: 1.85;
  color: var(--slate);
}

.page-about .about-versions__story {
  display: flex;
  flex-direction: column;
  gap: 16px;
}

.page-about .about-versions__p {
  max-width: 68ch;
  margin: 0;
  font-size: 15px;
  line-height: 2;
  color: var(--text);
}

.page-about .about-versions__figure {
  margin: 6px 0 0;
}

.page-about .about-versions__figure .figure__frame {
  aspect-ratio: 10 / 7;
  border: 1px solid var(--line-ink);
  overflow: hidden;
  background: var(--ink);
}

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

.page-about .about-versions__figure .figure__caption {
  margin-top: 8px;
  font-family: var(--font-mono);
  font-size: 11.5px;
  letter-spacing: .02em;
  color: var(--mist);
}

/* 03 服务范围 */
.page-about .about-reach {
  background: var(--cream);
}

.page-about .about-reach__grid {
  display: grid;
  gap: clamp(24px, 4vw, 40px);
}

.page-about .about-reach__viz {
  background: var(--ink);
  border: 1px solid var(--ink-deep);
  padding: clamp(10px, 2vw, 18px);
}

.page-about .reach-map {
  display: block;
  width: 100%;
  height: auto;
  max-width: 100%;
}

.page-about .reach-map:focus-visible {
  outline: 2px solid var(--signal);
  outline-offset: 4px;
}

.page-about .reach-map__rings circle {
  fill: none;
  stroke: rgba(244, 241, 234, .16);
  stroke-width: 1;
}

.page-about .reach-map__rings line {
  stroke: rgba(244, 241, 234, .08);
  stroke-width: 1;
}

.page-about .reach-map__nodes circle {
  fill: var(--celadon-pale);
  opacity: .85;
}

.page-about .reach-map__hub {
  fill: var(--signal);
}

.page-about .reach-map__hub-label {
  fill: var(--cream);
  font-family: var(--font-mono);
  font-size: 13px;
  letter-spacing: .04em;
}

.page-about .reach-map__tip {
  opacity: 0;
  transition: opacity .2s var(--ease);
}

.page-about .reach-map__tip rect {
  fill: var(--signal);
}

.page-about .reach-map__tip text {
  fill: var(--ink-deep);
  font-family: var(--font-mono);
  font-size: 12px;
}

.page-about .about-reach__viz:hover .reach-map__tip,
.page-about .reach-map:focus-visible ~ .reach-map__tip,
.page-about .reach-map__tip {
  opacity: 0;
}

.page-about .about-reach__viz:hover .reach-map__tip {
  opacity: 1;
}

.page-about .about-reach__info p.about-reach__p {
  margin: 0 0 18px;
  font-size: 15px;
  line-height: 1.95;
  color: var(--text);
}

.page-about .about-reach__channels {
  margin: 0 0 20px;
  padding: 0;
  list-style: none;
  border-top: 1px solid var(--line-ink-strong);
}

.page-about .about-channel {
  display: grid;
  gap: 3px;
  padding: 13px 0;
  border-bottom: 1px solid var(--line-ink);
}

.page-about .about-channel__key {
  font-family: var(--font-mono);
  font-size: 11.5px;
  letter-spacing: .06em;
  color: var(--celadon);
}

.page-about .about-channel__val {
  font-size: 15px;
  font-weight: 600;
  line-height: 1.6;
  color: var(--ink);
  word-break: break-word;
}

.page-about .about-channel__val.num {
  font-family: var(--font-mono);
  letter-spacing: .02em;
}

.page-about .about-channel__note {
  font-size: 12.5px;
  line-height: 1.7;
  color: var(--mist);
}

.page-about .about-reach__link {
  align-self: flex-start;
}

/* 04 团队 */
.page-about .about-team {
  background: var(--paper);
  border-top: 1px solid var(--line-ink);
}

.page-about .about-team__grid {
  display: grid;
  gap: clamp(24px, 4vw, 40px);
}

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

.page-about .about-team__figure .figure__frame {
  aspect-ratio: 3 / 2;
  border: 1px solid var(--line-ink);
  overflow: hidden;
}

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

.page-about .about-team__figure .figure__caption {
  margin-top: 8px;
  font-family: var(--font-mono);
  font-size: 11.5px;
  letter-spacing: .02em;
  color: var(--mist);
}

.page-about .about-team__list {
  display: grid;
  gap: 1px;
  margin: 0 0 20px;
  padding: 0;
  list-style: none;
  background: var(--line-ink);
  border: 1px solid var(--line-ink);
}

.page-about .about-team__item {
  padding: 14px 16px;
  background: var(--paper);
}

.page-about .about-team__item h3 {
  margin: 0 0 6px;
  font-size: 16px;
  line-height: 1.4;
  color: var(--ink);
}

.page-about .about-team__item p {
  margin: 0;
  font-size: 13.5px;
  line-height: 1.8;
  color: var(--slate);
}

.page-about .about-team__notes {
  padding: 18px;
  background: var(--celadon-pale);
  border-left: 3px solid var(--celadon);
}

.page-about .about-team__notes p {
  margin: 0 0 12px;
  font-size: 14px;
  line-height: 1.9;
  color: var(--text);
}

.page-about .about-team__notes p:last-of-type {
  margin-bottom: 16px;
}

/* 05 数据与生态 */
.page-about .about-proof {
  background: var(--ink);
  color: var(--cream);
}

.page-about .about-proof .about-sec-head h2 {
  color: var(--paper);
}

.page-about .about-proof .about-sec-head__lead {
  color: rgba(244, 241, 234, .72);
}

.page-about .about-proof .about-sec-head .eyebrow {
  color: var(--celadon-pale);
}

.page-about .about-proof__stats {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 1px;
  margin-bottom: clamp(24px, 4vw, 40px);
  background: var(--line-light);
  border: 1px solid var(--line-light);
}

.page-about .about-stat {
  display: flex;
  flex-direction: column;
  gap: 6px;
  padding: 18px 14px;
  background: var(--ink);
}

.page-about .about-stat__num {
  font-size: clamp(26px, 4vw, 40px);
  font-weight: 700;
  line-height: 1;
  color: var(--cream);
}

.page-about .about-stat:nth-child(2) .about-stat__num {
  color: var(--celadon-pale);
}

.page-about .about-stat__label {
  font-size: 12.5px;
  line-height: 1.7;
  color: rgba(244, 241, 234, .62);
}

.page-about .about-proof__eco {
  display: grid;
  gap: 1px;
  background: var(--line-light);
  border: 1px solid var(--line-light);
}

.page-about .about-eco {
  padding: clamp(18px, 3vw, 26px);
  background: var(--ink);
}

.page-about .about-eco__title {
  margin: 0 0 10px;
  font-size: 16px;
  line-height: 1.4;
  color: var(--signal);
  letter-spacing: .01em;
}

.page-about .about-eco__text {
  margin: 0;
  font-size: 14px;
  line-height: 1.95;
  color: rgba(244, 241, 234, .78);
}

/* 下一步 */
.page-about .about-next {
  background: var(--cream);
}

.page-about .about-next__grid {
  display: grid;
  gap: 1px;
  background: var(--line-ink);
  border: 1px solid var(--line-ink);
}

.page-about .about-next__card {
  display: flex;
  flex-direction: column;
  gap: 6px;
  padding: 18px 16px;
  background: var(--paper);
  text-decoration: none;
  color: var(--text);
  transition: border-color .18s var(--ease), transform .18s var(--ease);
  border-left: 3px solid transparent;
}

.page-about .about-next__card:hover,
.page-about .about-next__card:focus-visible {
  border-left-color: var(--signal);
  transform: translateX(2px);
}

.page-about .about-next__card:focus-visible {
  outline: 2px solid var(--signal);
  outline-offset: 2px;
}

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

.page-about .about-next__title {
  font-size: 17px;
  font-weight: 700;
  color: var(--ink);
}

.page-about .about-next__desc {
  font-size: 13px;
  line-height: 1.75;
  color: var(--slate);
}

@media (min-width: 760px) {
  .page-about .about-intro__facts {
    grid-template-columns: repeat(4, minmax(0, 1fr));
  }

  .page-about .about-fact {
    padding: 20px 18px;
  }

  .page-about .about-intro__figure .figure__frame {
    aspect-ratio: 8 / 3;
  }

  .page-about .about-who__grid {
    grid-template-columns: repeat(2, minmax(0, 1fr));
    gap: 20px;
  }

  .page-about .about-reach__grid {
    grid-template-columns: minmax(0, 5fr) minmax(0, 7fr);
    align-items: start;
  }

  .page-about .about-reach__viz {
    position: sticky;
    top: 24px;
  }

  .page-about .about-team__grid {
    grid-template-columns: minmax(0, 5fr) minmax(0, 7fr);
    align-items: start;
  }

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

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

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

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

@media (min-width: 980px) {
  .page-about .about-versions__body {
    grid-template-columns: minmax(0, 3fr) minmax(0, 9fr);
    gap: clamp(32px, 5vw, 68px);
    align-items: start;
  }

  .page-about .about-versions__rail {
    position: sticky;
    top: 24px;
  }

  .page-about .about-intro__title {
    max-width: 20ch;
  }
}

@media (prefers-reduced-motion: reduce) {
  .page-about .about-next__card,
  .page-about .reach-map__tip {
    transition: none;
  }

  .page-about .about-next__card:hover,
  .page-about .about-next__card:focus-visible {
    transform: none;
  }
}


</main>