.page-about {
  --about-hair: rgba(201, 214, 226, .16);
  --about-hair-strong: rgba(201, 214, 226, .34);
  --about-soft: rgba(242, 245, 248, .78);
  --about-softer: rgba(242, 245, 248, .6);
  padding-bottom: 96px;
  color: var(--paper);
}

/* ---------- 面包屑与首屏 ---------- */

.page-about .crumbs {
  margin: 28px 0 0;
}

.page-about .about-hero {
  position: relative;
  padding: 26px 0 44px;
  border-bottom: 1px solid var(--about-hair);
  overflow: hidden;
}

.page-about .about-hero::before {
  content: "";
  position: absolute;
  top: 0;
  right: 0;
  bottom: 0;
  width: 46%;
  background-image:
    linear-gradient(var(--about-hair) 1px, transparent 1px),
    linear-gradient(90deg, var(--about-hair) 1px, transparent 1px);
  background-size: 46px 46px;
  -webkit-mask-image: linear-gradient(90deg, transparent, #000 70%);
  mask-image: linear-gradient(90deg, transparent, #000 70%);
  pointer-events: none;
}

.page-about .about-hero > * {
  position: relative;
}

.page-about .about-hero h1 {
  margin: 18px 0 0;
  font-family: var(--font-display);
  font-weight: 800;
  font-size: clamp(30px, 7.4vw, 62px);
  line-height: 1.04;
  letter-spacing: -.02em;
  max-width: 17ch;
  color: var(--paper);
}

.page-about .about-hero .lede {
  margin: 20px 0 0;
  max-width: 60ch;
  font-size: 16px;
  line-height: 1.85;
  color: var(--about-soft);
}

.page-about .about-stats {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 1px;
  margin: 32px 0 0;
  background: var(--about-hair);
  border: 1px solid var(--about-hair);
}

.page-about .about-stats__item {
  background: var(--navy-900);
  padding: 15px 16px 17px;
}

.page-about .about-stats dt {
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: .1em;
  color: var(--mist);
}

.page-about .about-stats dd {
  margin: 8px 0 0;
  font-family: var(--font-mono);
  font-size: 26px;
  line-height: 1;
  color: var(--amber);
  font-variant-numeric: tabular-nums;
}

@media (min-width: 760px) {
  .page-about .about-stats {
    grid-template-columns: repeat(4, minmax(0, 1fr));
    margin-top: 40px;
  }

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

/* ---------- 双轨主体 ---------- */

.page-about .about-body {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 34px;
  padding-top: 40px;
}

.page-about .about-rail__cap,
.page-about .about-rail__end {
  margin: 0 0 8px;
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: .12em;
  color: var(--mist);
}

.page-about .about-rail__end {
  margin: 8px 0 0;
}

.page-about .about-rail__list {
  list-style: none;
  margin: 0;
  padding: 0 0 6px;
  display: flex;
  gap: 8px;
  overflow-x: auto;
  scrollbar-width: none;
}

.page-about .about-rail__list::-webkit-scrollbar {
  display: none;
}

.page-about .about-rail__link {
  display: flex;
  align-items: center;
  gap: 8px;
  flex: 0 0 auto;
  padding: 8px 12px;
  border: 1px solid var(--about-hair);
  border-radius: 2px;
  background: var(--navy-700);
  font-size: 13px;
  color: var(--about-soft);
  text-decoration: none;
  white-space: nowrap;
  transition: border-color .24s var(--ease), color .24s var(--ease), background .24s var(--ease);
}

.page-about .about-rail__link:hover,
.page-about .about-rail__link:focus-visible {
  border-color: var(--amber);
  color: var(--paper);
}

.page-about .about-rail__num {
  font-family: var(--font-mono);
  font-size: 12px;
  color: var(--amber);
}

@media (min-width: 1024px) {
  .page-about .about-body {
    grid-template-columns: 204px minmax(0, 1fr);
    gap: 60px;
    padding-top: 52px;
  }

  .page-about .about-rail {
    position: sticky;
    top: 40px;
    align-self: start;
  }

  .page-about .about-rail__list {
    flex-direction: column;
    gap: 0;
    overflow: visible;
    padding: 0;
    border-left: 1px solid var(--about-hair);
  }

  .page-about .about-rail__link {
    position: relative;
    padding: 11px 0 11px 18px;
    border: 0;
    border-radius: 0;
    background: none;
    white-space: normal;
  }

  .page-about .about-rail__link::before {
    content: "";
    position: absolute;
    left: -4.5px;
    top: 50%;
    width: 8px;
    height: 8px;
    margin-top: -4px;
    border-radius: 50%;
    background: var(--navy-900);
    border: 1px solid var(--mist);
    transition: background .24s var(--ease), border-color .24s var(--ease);
  }

  .page-about .about-rail__link:hover::before,
  .page-about .about-rail__link:focus-visible::before {
    background: var(--amber);
    border-color: var(--amber);
  }

  .page-about .about-rail__cap,
  .page-about .about-rail__end {
    padding-left: 18px;
  }
}

/* ---------- 叙事块 ---------- */

.page-about .stage {
  position: relative;
  padding-bottom: 52px;
  margin-bottom: 52px;
  border-bottom: 1px solid var(--about-hair);
}

.page-about .stage:last-child {
  padding-bottom: 0;
  margin-bottom: 0;
  border-bottom: 0;
}

.page-about .stage__num {
  display: inline-flex;
  align-items: center;
  gap: 12px;
  margin: 0 0 14px;
  font-family: var(--font-mono);
  font-size: 13px;
  letter-spacing: .12em;
  color: var(--amber);
}

.page-about .stage__num::after {
  content: "";
  width: 44px;
  height: 1px;
  background: var(--about-hair-strong);
}

.page-about .stage h2 {
  margin: 0 0 16px;
  font-family: var(--font-display);
  font-weight: 800;
  font-size: clamp(24px, 4.6vw, 38px);
  line-height: 1.12;
  letter-spacing: -.015em;
  max-width: 24ch;
  color: var(--paper);
}

.page-about .stage p {
  margin: 0 0 14px;
  max-width: 64ch;
  font-size: 16px;
  line-height: 1.82;
  color: var(--about-soft);
}

.page-about .stage__tail {
  margin: 22px 0 0 !important;
  padding-left: 16px;
  border-left: 2px solid var(--about-hair-strong);
  font-size: 15px !important;
  color: var(--about-softer) !important;
}

.page-about .about-link {
  color: var(--amber);
  text-decoration: none;
  border-bottom: 1px solid rgba(223, 166, 58, .45);
  transition: border-color .2s var(--ease);
}

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

/* ---------- 升级清单 ---------- */

.page-about .upgrades {
  list-style: none;
  margin: 26px 0 0;
  padding: 0;
  border-top: 1px solid var(--about-hair);
}

.page-about .upgrades__row {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 6px;
  padding: 16px 0;
  border-bottom: 1px solid var(--about-hair);
}

.page-about .upgrades__idx {
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: .08em;
  color: var(--mist);
}

.page-about .upgrades__row p {
  margin: 0;
  max-width: 62ch;
  font-size: 15px;
  line-height: 1.78;
  color: var(--about-soft);
}

.page-about .upgrades__row strong {
  color: var(--paper);
  font-weight: 600;
}

@media (min-width: 780px) {
  .page-about .upgrades__row {
    grid-template-columns: 92px minmax(0, 1fr);
    gap: 26px;
    align-items: start;
  }

  .page-about .upgrades__idx {
    padding-top: 3px;
  }
}

/* ---------- 图片与图注 ---------- */

.page-about .about-figure {
  margin: 34px 0;
  position: relative;
  border: 1px solid var(--about-hair);
  background: var(--navy-700);
}

.page-about .about-figure img {
  display: block;
  width: 100%;
  max-width: 100%;
  height: auto;
  object-fit: cover;
  filter: saturate(.55) contrast(1.05) brightness(.92);
}

.page-about .about-figure figcaption {
  display: flex;
  flex-wrap: wrap;
  align-items: baseline;
  gap: 10px;
  padding: 11px 15px;
  border-top: 1px solid var(--about-hair);
  background: var(--navy-900);
  font-family: var(--font-mono);
  font-size: 12px;
  line-height: 1.6;
  letter-spacing: .03em;
  color: var(--mist);
}

.page-about .about-figure figcaption b {
  color: var(--amber);
  font-weight: 500;
  white-space: nowrap;
}

/* ---------- 四步流程 ---------- */

.page-about .steps {
  list-style: none;
  margin: 26px 0 0;
  padding: 0;
  display: grid;
  gap: 1px;
  background: var(--about-hair);
  border: 1px solid var(--about-hair);
}

.page-about .steps__item {
  display: grid;
  grid-template-columns: auto minmax(0, 1fr);
  gap: 14px;
  align-items: start;
  padding: 18px 18px 20px;
  background: var(--navy-700);
  transition: background .24s var(--ease);
}

.page-about .steps__item:hover {
  background: var(--navy-600);
}

.page-about .steps__idx {
  font-family: var(--font-mono);
  font-size: 13px;
  color: var(--amber);
  padding-top: 3px;
}

.page-about .steps__item h3 {
  margin: 0 0 6px;
  font-size: 16px;
  font-weight: 600;
  letter-spacing: .01em;
  color: var(--paper);
}

.page-about .steps__item p {
  margin: 0;
  max-width: 58ch;
  font-size: 14.5px;
  line-height: 1.74;
  color: var(--about-softer);
}

/* ---------- 团队 ---------- */

.page-about .team-grid {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 1px;
  margin-top: 26px;
  background: var(--about-hair);
  border: 1px solid var(--about-hair);
}

.page-about .team-card {
  padding: 22px 20px 24px;
  background: var(--navy-600);
  transition: background .24s var(--ease), box-shadow .24s var(--ease);
}

.page-about .team-card:hover {
  background: var(--navy-700);
  box-shadow: inset 0 -2px 0 var(--amber);
}

.page-about .team-card__value {
  margin: 0;
  font-family: var(--font-mono);
  font-size: 40px;
  line-height: 1;
  color: var(--amber);
  font-variant-numeric: tabular-nums;
}

.page-about .team-card__unit {
  margin-left: 6px;
  font-family: var(--font-body);
  font-size: 14px;
  color: var(--mist);
}

.page-about .team-card__title {
  margin: 12px 0 8px;
  font-size: 16px;
  font-weight: 600;
  color: var(--paper);
}

.page-about .team-card p {
  margin: 0;
  max-width: 46ch;
  font-size: 14.5px;
  line-height: 1.74;
  color: var(--about-softer);
}

@media (min-width: 780px) {
  .page-about .team-grid {
    grid-template-columns: repeat(3, minmax(0, 1fr));
    margin-top: 30px;
  }
}

/* ---------- 数据迁移对照 ---------- */

.page-about .migrate {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 1px;
  margin-top: 28px;
  background: var(--about-hair);
  border: 1px solid var(--about-hair);
}

.page-about .migrate__col {
  padding: 20px;
  background: var(--navy-700);
}

.page-about .migrate__col--now {
  background: var(--navy-600);
  box-shadow: inset 3px 0 0 var(--amber);
}

.page-about .migrate__tag {
  margin: 0 0 8px;
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: .12em;
  color: var(--mist);
}

.page-about .migrate__title {
  margin: 0 0 10px;
  font-size: 16px;
  font-weight: 600;
  color: var(--paper);
}

.page-about .migrate__count {
  font-family: var(--font-mono);
  font-size: 20px;
  color: var(--amber);
  font-variant-numeric: tabular-nums;
}

.page-about .migrate__col p:last-child {
  margin: 0;
  max-width: 46ch;
  font-size: 14.5px;
  line-height: 1.74;
  color: var(--about-softer);
}

@media (min-width: 720px) {
  .page-about .migrate {
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }
}

/* ---------- 协作区 ---------- */

.page-about .collab {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 22px;
}

.page-about .collab__text p {
  margin: 0 0 14px;
  max-width: 60ch;
  font-size: 15.5px;
  line-height: 1.82;
  color: var(--about-soft);
}

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

@media (min-width: 920px) {
  .page-about .collab {
    grid-template-columns: minmax(0, 1.05fr) minmax(0, .85fr);
    gap: 34px;
    align-items: start;
  }
}

/* ---------- 协作标签墙 ---------- */

.page-about .tagwall {
  list-style: none;
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 1px;
  margin: 30px 0 0;
  padding: 0;
  background: var(--about-hair);
  border: 1px solid var(--about-hair);
}

.page-about .tagwall__item {
  padding: 15px 16px 17px;
  background: var(--navy-900);
  transition: background .24s var(--ease);
}

.page-about .tagwall__item:hover,
.page-about .tagwall__item:focus-within {
  background: var(--navy-600);
}

.page-about .tagwall__name {
  display: block;
  margin-bottom: 6px;
  font-size: 14.5px;
  font-weight: 600;
  color: var(--paper);
}

.page-about .tagwall__hint {
  display: block;
  font-size: 13px;
  line-height: 1.62;
  color: var(--mist);
}

@media (min-width: 560px) {
  .page-about .tagwall {
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }
}

@media (min-width: 1080px) {
  .page-about .tagwall {
    grid-template-columns: repeat(4, minmax(0, 1fr));
  }
}

/* ---------- 减弱动效 ---------- */

@media (prefers-reduced-motion: reduce) {
  .page-about .about-rail__link,
  .page-about .steps__item,
  .page-about .team-card,
  .page-about .tagwall__item,
  .page-about .about-rail__link::before {
    transition: none;
  }
}