.page-about {
  --about-gap: clamp(46px, 7vw, 104px);
  --about-aside: clamp(96px, 18vw, 240px);
  background: var(--ink-0);
  color: var(--paper);
  overflow-x: clip;
}

.page-about .container {
  width: 100%;
  max-width: var(--container);
  margin-inline: auto;
  padding-inline: var(--gutter);
}

.page-about .breadcrumbs {
  padding-top: var(--space-2);
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: .08em;
  text-transform: uppercase;
}

.page-about .breadcrumbs__link {
  color: var(--mute);
  text-decoration: none;
}

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

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

.page-about .breadcrumbs__current {
  color: var(--paper);
}

/* 01 首屏 */
.page-about .about-hero {
  padding-block: var(--space-2) var(--about-gap);
  position: relative;
}

.page-about .about-hero::before {
  content: "";
  position: absolute;
  inset: -10% -20% auto 40%;
  height: 340px;
  background: radial-gradient(60% 60% at 60% 30%, rgba(23, 230, 194, .14), transparent 72%);
  pointer-events: none;
}

.page-about .about-hero__inner {
  position: relative;
  display: grid;
  gap: var(--space-2);
  align-items: end;
}

.page-about .eyebrow {
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: .18em;
  text-transform: uppercase;
  color: var(--amber);
  margin: 0 0 var(--space-1);
}

.page-about .about-title {
  margin: 0;
  font-family: var(--font-display);
  font-weight: 800;
  font-size: clamp(34px, 8.4vw, 68px);
  line-height: .98;
  letter-spacing: -.01em;
  text-wrap: balance;
}

.page-about .about-hero__lede {
  margin: var(--space-2) 0 0;
  max-width: 52ch;
  font-size: clamp(15px, 3.6vw, 18px);
  line-height: 1.75;
  color: var(--mute);
}

.page-about .about-hero__facts {
  list-style: none;
  margin: var(--space-2) 0 0;
  padding: 0;
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 1px;
  background: var(--line);
  border: 1px solid var(--line);
  border-radius: var(--radius-m);
  overflow: hidden;
}

.page-about .about-hero__facts li {
  background: var(--ink-1);
  padding: var(--space-1);
  display: flex;
  flex-direction: column;
  gap: 4px;
}

.page-about .about-hero__facts .data-num {
  font-family: var(--font-mono);
  font-size: clamp(18px, 4.6vw, 26px);
  font-weight: 600;
  color: var(--cyan);
  line-height: 1.1;
}

.page-about .about-hero__facts li span:last-child {
  font-size: 12px;
  color: var(--mute);
  letter-spacing: .04em;
}

.page-about .about-hero__media {
  margin: 0;
  border-radius: var(--radius-l) var(--radius-s) var(--radius-l) var(--radius-s);
  overflow: hidden;
  border: 1px solid var(--line);
  background: var(--ink-2);
}

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

.page-about .about-hero__media .media__img {
  aspect-ratio: 16 / 9;
}

.page-about .media__caption {
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: .04em;
  color: var(--mute);
  padding: 8px 12px;
  border-top: 1px solid var(--line);
  background: rgba(6, 17, 14, .55);
}

/* 章节骨架 */
.page-about .about-chapter {
  padding-block: var(--about-gap);
  border-top: 1px solid var(--line);
}

.page-about .about-chapter__grid {
  display: grid;
  gap: var(--space-2);
}

.page-about .chapter-aside {
  display: flex;
  align-items: baseline;
  gap: var(--space-1);
}

.page-about .chapter-num {
  font-family: var(--font-display);
  font-weight: 800;
  font-size: clamp(38px, 11vw, 64px);
  line-height: .8;
  color: transparent;
  -webkit-text-stroke: 1px var(--teal);
}

.page-about .chapter-kicker {
  margin: 0;
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: .16em;
  text-transform: uppercase;
  color: var(--mute);
}

.page-about .chapter-body {
  max-width: var(--measure);
}

.page-about .chapter-title {
  margin: 0;
  font-family: var(--font-display);
  font-weight: 700;
  font-size: clamp(26px, 6vw, 40px);
  line-height: 1.06;
  letter-spacing: -.005em;
}

.page-about .chapter-intro {
  margin: var(--space-1) 0 0;
  font-size: clamp(15px, 3.6vw, 17px);
  line-height: 1.75;
  color: var(--mute);
}

.page-about .chapter-note {
  margin: var(--space-2) 0 0;
  padding-left: var(--space-1);
  border-left: 2px solid var(--amber);
  font-size: 14px;
  line-height: 1.8;
  color: var(--mute);
}

.page-about .chapter-note .link-quiet {
  color: var(--cyan);
  text-decoration: none;
  border-bottom: 1px solid var(--cyan-mid);
}

.page-about .chapter-note .link-quiet:hover,
.page-about .chapter-note .link-quiet:focus-visible {
  color: var(--amber);
  border-bottom-color: var(--amber);
}

/* 时间轴 */
.page-about .about-timeline__media {
  margin: var(--space-2) 0 0;
  border-radius: var(--radius-m);
  overflow: hidden;
  border: 1px solid var(--line);
}

.page-about .about-timeline__media .media__img {
  aspect-ratio: 21 / 9;
  filter: saturate(.8) contrast(1.05);
}

.page-about .timeline {
  list-style: none;
  margin: var(--space-2) 0 0;
  padding: 0;
  position: relative;
}

.page-about .timeline__item {
  position: relative;
  display: grid;
  gap: 6px;
  padding: var(--space-1) 0 var(--space-1) 24px;
  border-bottom: 1px dashed rgba(43, 74, 65, .8);
  background-image: linear-gradient(100deg, var(--cyan-soft), transparent 46%);
  background-size: 0% 100%;
  background-repeat: no-repeat;
  transition: background-size .28s ease, transform .2s ease;
}

.page-about .timeline__item::before {
  content: "";
  position: absolute;
  left: 4px;
  top: 26px;
  width: 8px;
  height: 8px;
  border-radius: 50%;
  background: var(--teal);
  box-shadow: 0 0 0 3px rgba(14, 158, 134, .16);
  transition: background .2s ease, box-shadow .2s ease;
}

.page-about .timeline__item:hover,
.page-about .timeline__item:focus-visible {
  background-size: 100% 100%;
  transform: translateX(3px);
  outline: none;
}

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

.page-about .timeline__item:hover::before,
.page-about .timeline__item:focus-visible::before {
  background: var(--amber);
  box-shadow: 0 0 0 4px var(--amber-soft);
}

.page-about .timeline__year {
  font-family: var(--font-display);
  font-weight: 800;
  font-size: clamp(36px, 10vw, 58px);
  line-height: .85;
  letter-spacing: .01em;
  color: var(--line);
  transition: color .2s ease;
}

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

.page-about .timeline__ver {
  margin: 0;
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: .16em;
  text-transform: uppercase;
  color: var(--amber);
}

.page-about .timeline__title {
  margin: 4px 0 0;
  font-family: var(--font-display);
  font-weight: 700;
  font-size: clamp(18px, 4.4vw, 22px);
  line-height: 1.2;
}

.page-about .timeline__note {
  margin: 6px 0 0;
  font-size: 14px;
  line-height: 1.75;
  color: var(--mute);
}

/* 团队 */
.page-about .crew {
  display: grid;
  gap: var(--space-1);
  margin-top: var(--space-2);
}

.page-about .crew-card {
  background: var(--ink-1);
  border: 1px solid var(--line);
  border-radius: var(--radius-s) var(--radius-l) var(--radius-s) var(--radius-l);
  padding: var(--space-2) var(--space-1);
  transition: transform .2s ease, border-color .2s ease;
}

.page-about .crew-card:hover {
  transform: translateY(-2px);
  border-color: var(--teal);
}

.page-about .crew-card:nth-child(2) {
  border-radius: var(--radius-l) var(--radius-s) var(--radius-l) var(--radius-s);
  background: linear-gradient(160deg, var(--amber-soft), var(--ink-1) 62%);
}

.page-about .crew-card:nth-child(3) {
  background: linear-gradient(200deg, var(--cyan-soft), var(--ink-1) 58%);
}

.page-about .crew-card__num {
  margin: 0;
  font-family: var(--font-mono);
  font-size: clamp(28px, 7vw, 38px);
  font-weight: 600;
  line-height: 1;
  color: var(--paper);
}

.page-about .crew-card--cyan .crew-card__num {
  color: var(--cyan);
}

.page-about .crew-card--amber .crew-card__num {
  color: var(--amber);
}

.page-about .crew-card__role {
  margin: 10px 0 0;
  font-family: var(--font-display);
  font-weight: 700;
  font-size: 19px;
  letter-spacing: .02em;
}

.page-about .crew-card__desc {
  margin: 6px 0 0;
  font-size: 14px;
  line-height: 1.7;
  color: var(--mute);
}

/* 数据协作流程 */
.page-about .flow {
  list-style: none;
  margin: var(--space-2) 0 0;
  padding: 0;
  display: grid;
  gap: 8px;
  counter-reset: flow;
}

.page-about .flow__step {
  display: grid;
  grid-template-columns: 28px minmax(0, 1fr);
  gap: 12px;
  align-items: start;
  padding: 12px var(--space-1);
  background: var(--ink-2);
  border-left: 2px solid var(--line);
  border-radius: 0 var(--radius-s) var(--radius-s) 0;
  transition: border-color .2s ease, background .2s ease;
}

.page-about .flow__step:hover {
  border-left-color: var(--cyan);
  background: var(--ink-1);
}

.page-about .flow__idx {
  font-family: var(--font-mono);
  font-size: 13px;
  font-weight: 600;
  color: var(--cyan);
  line-height: 1.7;
}

.page-about .flow__text {
  font-size: 14px;
  line-height: 1.75;
  color: var(--paper);
}

.page-about .about-process__media {
  margin: var(--space-2) 0 0;
  border-radius: var(--radius-m);
  overflow: hidden;
  border: 1px solid var(--line);
}

.page-about .about-process__media .media__img {
  aspect-ratio: 4 / 3;
}

/* 数字带 */
.page-about .about-chapter--band {
  background: linear-gradient(180deg, var(--ink-1), var(--ink-0) 88%);
}

.page-about .scale-band {
  margin-top: var(--space-2);
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 1px;
  background: var(--line);
  border: 1px solid var(--line);
  border-radius: var(--radius-m);
  overflow: hidden;
}

.page-about .scale-band__cell {
  background: var(--ink-2);
  padding: var(--space-1);
  display: flex;
  flex-direction: column;
  gap: 4px;
}

.page-about .scale-band__cell:nth-child(1),
.page-about .scale-band__cell:nth-child(4) {
  background: linear-gradient(150deg, rgba(23, 230, 194, .1), var(--ink-2) 70%);
}

.page-about .scale-band__num {
  margin: 0;
  font-family: var(--font-mono);
  font-size: clamp(22px, 5.6vw, 34px);
  font-weight: 600;
  line-height: 1.05;
  color: var(--cyan);
}

.page-about .scale-band__cell:nth-child(2) .scale-band__num,
.page-about .scale-band__cell:nth-child(5) .scale-band__num {
  color: var(--paper);
}

.page-about .scale-band__label {
  margin: 0;
  font-family: var(--font-display);
  font-weight: 700;
  font-size: 15px;
  letter-spacing: .04em;
  color: var(--paper);
}

.page-about .scale-band__meta {
  margin: 0;
  font-size: 12px;
  line-height: 1.6;
  color: var(--mute);
}

/* 合作与原则 */
.page-about .principles {
  margin-top: var(--space-2);
  display: grid;
  gap: var(--space-2);
}

.page-about .principle {
  padding-left: var(--space-1);
  border-left: 2px solid var(--line);
  transition: border-color .2s ease;
}

.page-about .principle:hover {
  border-left-color: var(--amber);
}

.page-about .principle__title {
  margin: 0;
  font-family: var(--font-display);
  font-weight: 700;
  font-size: clamp(18px, 4.4vw, 21px);
  line-height: 1.25;
}

.page-about .principle__text {
  margin: 6px 0 0;
  font-size: 14px;
  line-height: 1.8;
  color: var(--mute);
}

/* 收束 */
.page-about .about-close {
  padding-block: var(--about-gap);
  border-top: 1px solid var(--line);
  background:
    repeating-linear-gradient(115deg, rgba(255, 177, 61, .07) 0 2px, transparent 2px 22px),
    var(--ink-1);
}

.page-about .about-close__inner {
  max-width: 760px;
}

.page-about .about-close__title {
  margin: 0;
  font-family: var(--font-display);
  font-weight: 800;
  font-size: clamp(24px, 5.8vw, 38px);
  line-height: 1.12;
  text-wrap: balance;
}

.page-about .about-close__sub {
  margin: var(--space-1) 0 0;
  max-width: 54ch;
  font-size: 15px;
  line-height: 1.8;
  color: var(--mute);
}

.page-about .about-close__actions {
  margin-top: var(--space-2);
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: var(--space-1);
}

.page-about .btn {
  display: inline-block;
  padding: 12px 22px;
  border-radius: 999px;
  font-family: var(--font-mono);
  font-size: 13px;
  letter-spacing: .06em;
  text-decoration: none;
  border: 1px solid transparent;
  transition: transform .2s ease, background .2s ease, border-color .2s ease;
}

.page-about .btn--primary {
  background: var(--amber);
  color: var(--ink-0);
  font-weight: 600;
}

.page-about .btn--primary:hover {
  transform: translateY(-2px);
  background: #ffc466;
}

.page-about .btn--ghost {
  border-color: var(--teal);
  color: var(--cyan);
}

.page-about .btn--ghost:hover {
  transform: translateY(-2px);
  border-color: var(--cyan);
  background: var(--cyan-soft);
}

.page-about .btn:focus-visible,
.page-about .link-quiet:focus-visible {
  outline: 2px solid var(--cyan);
  outline-offset: 3px;
}

.page-about .about-close__actions .link-quiet {
  color: var(--mute);
  font-size: 13px;
  text-decoration: none;
  border-bottom: 1px solid var(--line);
}

.page-about .about-close__actions .link-quiet:hover {
  color: var(--cyan);
  border-bottom-color: var(--cyan);
}

/* 平板与桌面 */
@media (min-width: 720px) {
  .page-about .about-hero__facts {
    grid-template-columns: repeat(4, minmax(0, 1fr));
  }

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

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

  .page-about .principles {
    grid-template-columns: repeat(2, minmax(0, 1fr));
    gap: var(--space-2) var(--space-3);
  }

  .page-about .timeline__item {
    grid-template-columns: 168px minmax(0, 1fr);
    align-items: start;
    gap: var(--space-2);
    padding: var(--space-2) 0 var(--space-2) 28px;
  }

  .page-about .timeline__item::before {
    top: 40px;
  }

  .page-about .timeline__year {
    font-size: clamp(52px, 6vw, 78px);
  }
}

@media (min-width: 960px) {
  .page-about .about-hero__inner {
    grid-template-columns: minmax(0, 1.15fr) minmax(0, .85fr);
    gap: var(--space-3);
  }

  .page-about .about-chapter__grid {
    grid-template-columns: var(--about-aside) minmax(0, 1fr);
    gap: var(--space-3);
  }

  .page-about .chapter-aside {
    flex-direction: column;
    align-items: flex-start;
    gap: var(--space-1);
    position: sticky;
    top: 96px;
    align-self: start;
  }

  .page-about .chapter-num {
    font-size: clamp(64px, 6.4vw, 88px);
  }

  .page-about .chapter-body {
    max-width: 620px;
  }

  .page-about .about-timeline__media,
  .page-about .about-process__media {
    margin-top: var(--space-3);
  }
}

@media (prefers-reduced-motion: reduce) {
  .page-about .timeline__item,
  .page-about .crew-card,
  .page-about .flow__step,
  .page-about .btn,
  .page-about .principle {
    transition: none;
  }

  .page-about .timeline__item:hover,
  .page-about .crew-card:hover,
  .page-about .btn:hover {
    transform: none;
  }
}