.page-about {
  --about-w: min(1520px, 100% - 32px);
  --about-line: 1px solid var(--edge);
  background:
    radial-gradient(1100px 620px at 78% -12%, rgba(34, 245, 224, 0.07), transparent 68%),
    radial-gradient(900px 520px at 4% 32%, rgba(255, 106, 26, 0.05), transparent 70%),
    var(--void);
  color: var(--ice);
  overflow-x: hidden;
}

.page-about .shell {
  width: var(--about-w);
  margin-inline: auto;
}

/* ---------- 面包屑 ---------- */
.page-about .about-crumbs {
  padding-top: 18px;
}

/* ---------- 首屏 ---------- */
.page-about .about-hero {
  padding-block: 28px 52px;
  position: relative;
}

.page-about .about-hero::after {
  content: "";
  display: block;
  margin-top: 44px;
  height: 1px;
  background: linear-gradient(90deg, var(--cyan-dim), var(--edge) 45%, transparent);
}

.page-about .about-hero__grid {
  display: grid;
  gap: 26px;
}

.page-about .about-hero__rail {
  display: flex;
  align-items: baseline;
  flex-wrap: wrap;
  gap: 12px;
  padding-top: 10px;
  border-top: var(--about-line);
}

.page-about .about-rail__num {
  font-family: var(--font-mono);
  font-size: 26px;
  font-weight: 700;
  letter-spacing: -0.03em;
  color: var(--cyan);
  line-height: 1;
}

.page-about .about-rail__label {
  font-size: 12px;
  letter-spacing: 0.18em;
  text-transform: uppercase;
  color: var(--ice);
  opacity: 0.72;
}

.page-about .about-rail__meta {
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.06em;
  color: var(--orange);
}

.page-about .about-hero__title {
  margin: 12px 0 22px;
  font-weight: 250;
  line-height: 1.06;
  letter-spacing: -0.015em;
  color: var(--paper);
  max-width: 22ch;
}

.page-about .about-hero__body .lede {
  max-width: 62ch;
  margin: 0;
}

/* ---------- 事实条 ---------- */
.page-about .about-facts {
  list-style: none;
  margin: 34px 0 0;
  padding: 0;
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 1px;
  background: var(--edge);
  border: var(--about-line);
}

.page-about .about-facts li {
  background: linear-gradient(160deg, var(--deep), var(--void));
  padding: 16px 14px;
  display: flex;
  flex-direction: column;
  gap: 6px;
}

.page-about .about-facts__num {
  font-family: var(--font-mono);
  font-size: 24px;
  font-weight: 700;
  letter-spacing: -0.02em;
  color: var(--paper);
  line-height: 1;
}

.page-about .about-facts__num.num--signal {
  color: var(--orange);
}

.page-about .about-facts__label {
  font-size: 12px;
  letter-spacing: 0.1em;
  color: var(--ice);
  opacity: 0.68;
}

/* ---------- 通用小标题 ---------- */
.page-about .about-head {
  display: block;
}

.page-about .about-head__note {
  margin: 10px 0 0;
  font-size: 14px;
  color: var(--ice);
  opacity: 0.7;
}

/* ---------- 品牌起点 ---------- */
.page-about .about-origin {
  align-items: start;
}

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

.page-about .about-figure {
  position: relative;
  margin: 0;
  padding: 9px;
  background: var(--deep);
  border: var(--about-line);
}

.page-about .about-figure::after {
  content: "";
  position: absolute;
  inset: 6px;
  border: 1px solid var(--layer);
  transform: translate(9px, 9px);
  pointer-events: none;
  z-index: -1;
}

.page-about .about-figure img {
  display: block;
  width: 100%;
  height: auto;
  max-width: 100%;
  object-fit: cover;
  border: 1px solid var(--edge);
  filter: saturate(0.85) contrast(1.06);
}

.page-about .about-figure .media__caption {
  margin-top: 10px;
  font-size: 12px;
  line-height: 1.6;
  color: var(--ice);
  opacity: 0.66;
}

/* ---------- 时间线 ---------- */
.page-about .about-jump {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
  margin: 22px 0 34px;
}

.page-about .about-jump a {
  display: inline-block;
  padding: 6px 12px;
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.06em;
  color: var(--ice);
  text-decoration: none;
  background: var(--deep);
  border: var(--about-line);
  transition: color var(--dur) var(--ease), border-color var(--dur) var(--ease), background var(--dur) var(--ease);
}

.page-about .about-jump a:hover,
.page-about .about-jump a:focus-visible {
  color: var(--void);
  background: var(--cyan);
  border-color: var(--cyan);
  outline: none;
}

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

.page-about .about-timeline::before {
  content: "";
  position: absolute;
  left: 5px;
  top: 6px;
  bottom: 30px;
  width: 1px;
  background: linear-gradient(180deg, var(--cyan), var(--cyan-dim) 40%, var(--edge));
}

.page-about .about-timeline__item {
  position: relative;
  padding: 0 0 34px 34px;
}

.page-about .about-timeline__item::before {
  content: "";
  position: absolute;
  left: 0;
  top: 6px;
  width: 11px;
  height: 11px;
  border-radius: 50%;
  background: var(--void);
  border: 2px solid var(--cyan);
  transition: transform var(--dur) var(--ease), background var(--dur) var(--ease);
}

.page-about .about-timeline__item:hover::before,
.page-about .about-timeline__item:focus-within::before {
  background: var(--cyan);
  transform: scale(1.25);
}

.page-about .about-timeline__year {
  display: block;
  font-family: var(--font-mono);
  font-size: 15px;
  font-weight: 700;
  letter-spacing: 0.02em;
  color: var(--cyan);
  margin-bottom: 8px;
}

.page-about .about-timeline__year.num--signal {
  color: var(--orange);
}

.page-about .about-timeline__body h3 {
  margin: 0 0 8px;
  font-family: var(--font-display);
  font-size: 21px;
  font-weight: 400;
  letter-spacing: 0.01em;
  color: var(--paper);
}

.page-about .about-timeline__body p {
  margin: 0;
  font-size: 15px;
  line-height: 1.78;
  color: var(--ice);
  max-width: 66ch;
}

/* ---------- 版本演进 ---------- */
.page-about .about-versions__strip {
  list-style: none;
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
  margin: 0 0 28px;
  padding: 0;
}

.page-about .about-v {
  display: inline-block;
  font-family: var(--font-mono);
  font-size: 13px;
  font-weight: 600;
  letter-spacing: 0.04em;
  color: var(--ice);
  padding: 7px 12px;
  background: var(--deep);
  border: var(--about-line);
}

.page-about .about-v--current {
  color: var(--void);
  background: var(--orange);
  border-color: var(--orange);
}

.page-about .about-banner {
  margin: 0 0 30px;
  border: var(--about-line);
  padding: 8px;
  background: var(--deep);
}

.page-about .about-banner img {
  display: block;
  width: 100%;
  height: auto;
  max-width: 100%;
  object-fit: cover;
  border: 1px solid var(--edge);
}

.page-about .about-vcards {
  display: grid;
  gap: 16px;
  grid-template-columns: 1fr;
}

.page-about .about-vcard {
  padding: 22px 20px 24px;
  background: linear-gradient(165deg, var(--deep), var(--void));
}

.page-about .about-vcard__ver {
  display: inline-block;
  font-family: var(--font-mono);
  font-size: 13px;
  font-weight: 700;
  letter-spacing: 0.08em;
  color: var(--cyan);
  margin-bottom: 12px;
}

.page-about .about-vcard__ver.num--signal {
  color: var(--orange);
}

.page-about .about-vcard h3 {
  margin: 0 0 10px;
  font-family: var(--font-display);
  font-size: 22px;
  font-weight: 400;
  color: var(--paper);
  letter-spacing: 0.01em;
}

.page-about .about-vcard p {
  margin: 0;
  font-size: 14px;
  line-height: 1.78;
  color: var(--ice);
  opacity: 0.9;
}

/* ---------- 团队与流程 ---------- */
.page-about .about-team {
  align-items: start;
}

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

.page-about .about-figure--team {
  margin-top: 6px;
}

.page-about .about-steps {
  list-style: none;
  margin: 30px 0 0;
  padding: 0;
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 1px;
  background: var(--edge);
  border: var(--about-line);
}

.page-about .about-steps li {
  display: flex;
  align-items: center;
  gap: 10px;
  padding: 12px 14px;
  background: var(--deep);
  font-size: 13px;
  color: var(--ice);
  transition: background var(--dur) var(--ease), color var(--dur) var(--ease);
}

.page-about .about-steps li:hover {
  background: var(--layer);
  color: var(--paper);
}

.page-about .about-steps__i {
  font-family: var(--font-mono);
  font-size: 11px;
  font-weight: 700;
  letter-spacing: 0.08em;
  color: var(--orange);
}

/* ---------- 合作网络 ---------- */
.page-about .about-network {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 1px;
  background: var(--edge);
  border: var(--about-line);
  margin-bottom: 30px;
}

.page-about .about-network__stat {
  background: var(--deep);
  padding: 22px 18px;
  display: flex;
  flex-direction: column;
  gap: 8px;
}

.page-about .about-network__num {
  font-family: var(--font-mono);
  font-size: 40px;
  font-weight: 700;
  letter-spacing: -0.03em;
  line-height: 1;
  color: var(--paper);
}

.page-about .about-network__num.num--signal {
  color: var(--orange);
}

.page-about .about-network__label {
  font-size: 13px;
  letter-spacing: 0.05em;
  color: var(--ice);
  opacity: 0.72;
}

.page-about .about-network__prose {
  max-width: 72ch;
}

/* ---------- 选择理由与下一步 ---------- */
.page-about .about-why {
  padding-bottom: 96px;
}

.page-about .about-why__head {
  margin-bottom: 40px;
  padding-top: 20px;
  border-top: 1px solid var(--edge);
}

.page-about .about-why__title {
  margin: 14px 0 0;
  font-weight: 250;
  line-height: 1.06;
  letter-spacing: -0.015em;
  color: var(--paper);
  max-width: 20ch;
}

.page-about .about-why__list {
  list-style: none;
  margin: 0;
  padding: 0;
  display: grid;
  gap: 1px;
  background: var(--edge);
  border-top: var(--about-line);
}

.page-about .about-why__list li {
  background: var(--void);
  padding: 20px 0 20px 20px;
  border-left: 2px solid transparent;
  transition: border-color var(--dur) var(--ease), background var(--dur) var(--ease);
}

.page-about .about-why__list li:hover {
  border-left-color: var(--cyan);
  background: var(--deep);
}

.page-about .about-why__list h3 {
  margin: 0 0 8px;
  font-family: var(--font-display);
  font-size: 19px;
  font-weight: 400;
  letter-spacing: 0.02em;
  color: var(--cyan);
}

.page-about .about-why__list p {
  margin: 0;
  font-size: 14px;
  line-height: 1.78;
  color: var(--ice);
  max-width: 62ch;
}

.page-about .about-cta {
  align-self: start;
  padding: 28px 24px;
  background: linear-gradient(155deg, var(--deep), var(--void) 78%);
  border: var(--about-line);
  border-top: 3px solid var(--orange);
}

.page-about .about-cta__title {
  margin: 0 0 16px;
  font-family: var(--font-display);
  font-size: 26px;
  font-weight: 300;
  letter-spacing: 0.01em;
  color: var(--paper);
}

.page-about .about-cta p {
  margin: 0 0 14px;
  font-size: 14px;
  line-height: 1.78;
  color: var(--ice);
}

.page-about .about-cta__actions {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
  margin: 22px 0 4px;
}

.page-about .about-cta__link {
  margin: 16px 0 0;
  font-size: 13px;
}

.page-about .about-cta__link a {
  color: var(--cyan);
  text-decoration: none;
  border-bottom: 1px solid var(--cyan-dim);
  transition: border-color var(--dur) var(--ease), color var(--dur) var(--ease);
}

.page-about .about-cta__link a:hover,
.page-about .about-cta__link a:focus-visible {
  color: var(--paper);
  border-bottom-color: var(--paper);
  outline: none;
}

/* ---------- 响应式 ---------- */
@media (min-width: 640px) {
  .page-about .about-facts {
    grid-template-columns: repeat(4, minmax(0, 1fr));
  }

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

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

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

@media (min-width: 900px) {
  .page-about .about-hero {
    padding-block: 46px 64px;
  }

  .page-about .about-hero__grid {
    grid-template-columns: 180px minmax(0, 1fr);
    gap: 56px;
  }

  .page-about .about-hero__rail {
    position: sticky;
    top: calc(var(--header-h) + 28px);
    flex-direction: column;
    align-items: flex-start;
    gap: 10px;
    align-self: start;
    padding-top: 14px;
  }

  .page-about .about-rail__num {
    font-size: 34px;
  }

  .page-about .about-timeline::before {
    left: 108px;
  }

  .page-about .about-timeline__item {
    display: grid;
    grid-template-columns: 88px minmax(0, 1fr);
    gap: 40px;
    padding: 0 0 46px 0;
  }

  .page-about .about-timeline__item::before {
    left: 102px;
    top: 7px;
  }

  .page-about .about-timeline__year {
    text-align: left;
    margin-bottom: 0;
    padding-top: 2px;
  }

  .page-about .about-timeline__body h3 {
    font-size: 24px;
  }

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

  .page-about .about-banner {
    padding: 12px;
  }
}

@media (min-width: 1100px) {
  .page-about .about-why {
    padding-bottom: 120px;
  }

  .page-about .about-network__num {
    font-size: 48px;
  }
}

@media (prefers-reduced-motion: reduce) {
  .page-about .about-jump a,
  .page-about .about-timeline__item::before,
  .page-about .about-steps li,
  .page-about .about-why__list li,
  .page-about .about-cta__link a {
    transition: none;
  }
}