.page-about {
  background: var(--ink-900);
  color: var(--white);
  overflow-x: clip;
}

/* ---------------- 首屏 ---------------- */
.page-about .about-hero {
  position: relative;
  padding: calc(var(--header-h) + 36px) 0 clamp(32px, 5vw, 56px);
  border-bottom: 1px solid var(--line-soft);
}

.page-about .about-hero::before {
  content: "";
  position: absolute;
  top: -14%;
  right: -18%;
  width: min(820px, 96vw);
  height: min(540px, 68vw);
  background: radial-gradient(closest-side, rgba(23, 224, 122, .20), rgba(23, 224, 122, 0) 72%);
  transform: rotate(-8deg);
  pointer-events: none;
}

.page-about .about-hero .shell {
  position: relative;
}

.page-about .about-hero .breadcrumb {
  margin-bottom: clamp(28px, 5vw, 56px);
}

.page-about .about-hero__title {
  font-family: var(--font-display);
  font-weight: 800;
  font-size: clamp(46px, 10vw, 124px);
  line-height: .9;
  letter-spacing: -.015em;
  margin: 0 0 clamp(18px, 2.6vw, 30px);
  max-width: 14ch;
}

.page-about .about-hero__accent {
  color: var(--lime);
}

.page-about .about-hero__lede {
  max-width: 62ch;
  margin: 0 0 clamp(30px, 5vw, 56px);
}

.page-about .tally {
  list-style: none;
  margin: 0 0 clamp(28px, 4vw, 48px);
  padding: 0;
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  border-top: 1px solid var(--line-soft);
}

.page-about .tally__item {
  padding: 18px 14px 18px 0;
  border-bottom: 1px solid var(--line-soft);
  display: flex;
  flex-direction: column;
  gap: 6px;
  min-width: 0;
}

.page-about .tally__label {
  font-family: var(--font-mono);
  font-size: 11.5px;
  letter-spacing: .1em;
  color: var(--mist);
}

.page-about .about-hero__visual {
  margin: 0;
  width: min(100%, 860px);
  aspect-ratio: 3 / 2;
}

/* ---------------- 通用章节头 ---------------- */
.page-about .sec-head {
  margin-bottom: clamp(28px, 5vw, 56px);
}

.page-about .sec-title {
  font-family: var(--font-display);
  font-weight: 300;
  font-size: clamp(30px, 6.4vw, 66px);
  line-height: 1.04;
  letter-spacing: -.01em;
  margin: 12px 0 0;
  max-width: 20ch;
}

.page-about .sec-note {
  margin: 16px 0 0;
  max-width: 60ch;
  color: var(--mist);
  font-size: 15.5px;
  line-height: 1.7;
}

/* ---------------- 01 记录单位 ---------------- */
.page-about .about-view__grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: clamp(28px, 4vw, 48px);
}

.page-about .about-view__lead p {
  margin: 0 0 16px;
}

.page-about .about-view__lead p:last-child {
  margin-bottom: 0;
}

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

.page-about .vpair {
  display: grid;
  grid-template-columns: 68px minmax(0, 1fr);
  gap: 14px;
  padding: 16px 0;
  border-top: 1px solid var(--line-soft);
}

.page-about .vpair:last-child {
  border-bottom: 1px solid var(--line-soft);
}

.page-about .vpair dt {
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: .16em;
  color: var(--green);
  padding-top: 3px;
}

.page-about .vpair dd {
  margin: 0;
  font-size: 15.5px;
  line-height: 1.65;
  color: var(--white);
}

/* ---------------- 02 阶段演进 ---------------- */
.page-about .tl {
  display: grid;
  grid-template-columns: 1fr;
  gap: clamp(24px, 4vw, 40px);
}

.page-about .tl__marks {
  list-style: none;
  margin: 0;
  padding: 0;
  display: flex;
  flex-wrap: wrap;
  gap: 10px 22px;
}

.page-about .tl__marks a {
  position: relative;
  display: inline-flex;
  align-items: center;
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: .1em;
  color: var(--mist);
  text-decoration: none;
  transition: color var(--dur) var(--ease);
}

.page-about .tl__marks a:hover,
.page-about .tl__marks a:focus-visible {
  color: var(--lime);
}

.page-about .tl__stages {
  display: block;
}

.page-about .stage {
  display: grid;
  grid-template-columns: 44px minmax(0, 1fr);
  gap: clamp(14px, 3vw, 30px);
  padding: clamp(24px, 4vw, 40px) 0;
  border-top: 1px solid var(--line-soft);
  scroll-margin-top: calc(var(--header-h) + 24px);
  transition: background var(--dur) var(--ease), box-shadow var(--dur) var(--ease);
}

.page-about .stage:last-child {
  border-bottom: 1px solid var(--line-soft);
}

.page-about .stage:target {
  background: linear-gradient(90deg, rgba(23, 224, 122, .085), rgba(23, 224, 122, 0) 62%);
  box-shadow: inset 2px 0 0 var(--green);
}

.page-about .stage__mark {
  display: block;
  color: var(--green);
  opacity: .85;
  transition: color var(--dur) var(--ease), opacity var(--dur) var(--ease), transform var(--dur) var(--ease);
}

.page-about .stage__mark svg {
  display: block;
  width: 44px;
  height: 44px;
}

.page-about .stage:hover .stage__mark {
  color: var(--lime);
  opacity: 1;
  transform: translateX(3px);
}

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

.page-about .stage__idx {
  margin: 0 0 8px;
  font-family: var(--font-mono);
  font-size: 11.5px;
  letter-spacing: .18em;
  color: var(--mist);
}

.page-about .stage__name {
  font-family: var(--font-display);
  font-weight: 800;
  font-size: clamp(26px, 5.2vw, 50px);
  line-height: 1;
  letter-spacing: -.01em;
  margin: 0 0 14px;
}

.page-about .stage__text {
  margin: 0 0 14px;
  max-width: 56ch;
  color: var(--mist);
  font-size: 15.5px;
  line-height: 1.7;
}

.page-about .stage__note {
  margin: 0;
  display: inline-block;
  font-family: var(--font-mono);
  font-size: 11.5px;
  letter-spacing: .06em;
  line-height: 1.6;
  color: var(--mist);
  border-top: 1px solid var(--line-soft);
  padding-top: 10px;
  opacity: .7;
  transition: opacity var(--dur) var(--ease), color var(--dur) var(--ease);
}

.page-about .stage:hover .stage__note,
.page-about .stage:target .stage__note {
  opacity: 1;
  color: var(--green);
}

/* ---------------- 03 编辑流程 ---------------- */
.page-about .about-flow__visual {
  margin: 0 0 clamp(28px, 4vw, 48px);
  width: min(100%, 640px);
  aspect-ratio: 4 / 3;
}

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

.page-about .flow__step {
  display: grid;
  grid-template-columns: 40px minmax(0, 1fr);
  gap: clamp(14px, 2.5vw, 28px);
  padding: clamp(22px, 3.4vw, 34px) 0;
  border-top: 1px solid var(--line-soft);
}

.page-about .flow__step:last-child {
  border-bottom: 1px solid var(--line-soft);
}

.page-about .flow__num {
  font-family: var(--font-mono);
  font-size: 13px;
  letter-spacing: .08em;
  color: var(--green);
  padding-top: 6px;
}

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

.page-about .flow__title {
  font-family: var(--font-display);
  font-weight: 800;
  font-size: clamp(21px, 3.6vw, 30px);
  line-height: 1.1;
  margin: 0 0 10px;
}

.page-about .flow__text {
  margin: 0 0 12px;
  max-width: 60ch;
  color: var(--mist);
  font-size: 15.5px;
  line-height: 1.7;
}

.page-about .flow__beat {
  margin: 0;
  display: flex;
  flex-wrap: wrap;
  align-items: baseline;
  gap: 10px;
}

.page-about .flow__beat-label {
  font-family: var(--font-mono);
  font-size: 11.5px;
  letter-spacing: .16em;
  color: var(--mist);
}

.page-about .flow__beat .num {
  font-size: 19px;
  color: var(--lime);
}

/* ---------------- 04 团队分工 ---------------- */
.page-about .crew {
  display: grid;
  grid-template-columns: 1fr;
  border-top: 1px solid var(--line-soft);
}

.page-about .crew__unit {
  padding: clamp(24px, 3.4vw, 36px) 0;
  border-bottom: 1px solid var(--line-soft);
  min-width: 0;
}

.page-about .crew .crew__num {
  font-size: clamp(40px, 7vw, 72px);
  line-height: 1;
  margin: 0 0 12px;
  color: var(--lime);
}

.page-about .crew__role {
  font-family: var(--font-display);
  font-weight: 800;
  font-size: clamp(19px, 2.6vw, 23px);
  margin: 0 0 10px;
}

.page-about .crew__text {
  margin: 0;
  max-width: 40ch;
  color: var(--mist);
  font-size: 15px;
  line-height: 1.7;
}

.page-about .about-team__foot {
  margin: clamp(28px, 4vw, 44px) 0 0;
}

/* ---------------- 05 地域与协作 ---------------- */
.page-about .about-roots__grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: clamp(26px, 4vw, 52px);
}

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

.page-about .root {
  background: var(--ink-900);
  padding: clamp(16px, 2.6vw, 26px) clamp(13px, 2vw, 20px);
  display: flex;
  flex-direction: column;
  gap: 8px;
  min-width: 0;
}

.page-about .root__v {
  font-size: clamp(23px, 3.6vw, 34px);
  line-height: 1;
  color: var(--white);
}

.page-about .root__k {
  font-family: var(--font-mono);
  font-size: 11.5px;
  letter-spacing: .06em;
  line-height: 1.55;
  color: var(--mist);
}

.page-about .about-roots__aside {
  margin: clamp(26px, 4vw, 40px) 0 0;
  padding-top: 18px;
  border-top: 1px solid var(--line-soft);
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: .05em;
  line-height: 1.7;
  color: var(--mist);
}

/* ---------------- 06 栏目索引 ---------------- */
.page-about .cats {
  display: grid;
  grid-template-columns: 1fr;
  gap: clamp(24px, 3.6vw, 40px);
}

.page-about .cat {
  border-top: 1px solid var(--line-soft);
  padding-top: clamp(18px, 2.4vw, 26px);
  min-width: 0;
}

.page-about .cat__title {
  font-family: var(--font-mono);
  font-size: 11.5px;
  letter-spacing: .2em;
  color: var(--green);
  margin: 0 0 14px;
}

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

.page-about .cat__list li {
  padding: 12px 0;
  border-bottom: 1px solid var(--line-soft);
  display: flex;
  flex-direction: column;
  gap: 5px;
}

.page-about .cat__list a {
  font-family: var(--font-display);
  font-weight: 800;
  font-size: 19px;
  line-height: 1.2;
  color: var(--white);
  text-decoration: none;
  transition: color var(--dur) var(--ease);
}

.page-about .cat__list a:hover,
.page-about .cat__list a:focus-visible {
  color: var(--lime);
}

.page-about .cat__note {
  font-family: var(--font-mono);
  font-size: 11.5px;
  line-height: 1.55;
  color: var(--mist);
}

.page-about .about-index__visual {
  margin: clamp(34px, 5vw, 60px) auto 0;
  width: min(100%, 880px);
  aspect-ratio: 3 / 2;
}

.page-about .about-index__check {
  margin: clamp(32px, 5vw, 56px) 0 0;
  padding: clamp(24px, 3.6vw, 40px);
  border: 1px solid var(--line-soft);
  background: var(--ink-800);
  clip-path: polygon(0 0, 100% 0, 100% calc(100% - 30px), calc(100% - 30px) 100%, 0 100%);
}

.page-about .about-index__check h3 {
  font-family: var(--font-display);
  font-weight: 800;
  font-size: clamp(20px, 3vw, 27px);
  line-height: 1.15;
  margin: 0 0 12px;
}

.page-about .about-index__check p {
  margin: 0 0 22px;
  max-width: 62ch;
  color: var(--mist);
  font-size: 15.5px;
  line-height: 1.7;
}

.page-about .about-index__actions {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
}

/* ---------------- 显现与动效 ---------------- */
.page-about [data-reveal] {
  opacity: 0;
  transform: translateY(16px);
  transition: opacity .5s var(--ease), transform .5s var(--ease);
}

.page-about [data-reveal][data-visible="true"] {
  opacity: 1;
  transform: none;
}

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

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

  .page-about .tally__item {
    border-bottom: 0;
    border-left: 1px solid var(--line-soft);
    padding: 20px 16px 20px 22px;
  }

  .page-about .tally__item:first-child {
    border-left: 0;
    padding-left: 0;
  }

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

  .page-about .crew__unit {
    border-bottom: 0;
    border-left: 1px solid var(--line-soft);
    padding: clamp(28px, 3.6vw, 40px) clamp(20px, 2.4vw, 32px);
  }

  .page-about .crew__unit:first-child {
    border-left: 0;
    padding-left: 0;
  }

  .page-about .crew__unit:last-child {
    padding-right: 0;
  }
}

@media (min-width: 800px) {
  .page-about .cats {
    grid-template-columns: repeat(3, minmax(0, 1fr));
  }
}

@media (min-width: 900px) {
  .page-about .about-view__grid {
    grid-template-columns: minmax(0, 1.05fr) minmax(0, 1fr);
    gap: clamp(44px, 6vw, 92px);
    align-items: start;
  }

  .page-about .tl {
    grid-template-columns: 168px minmax(0, 1fr);
    gap: clamp(40px, 6vw, 84px);
    align-items: start;
  }

  .page-about .tl__rail {
    position: sticky;
    top: calc(var(--header-h) + 32px);
    align-self: start;
  }

  .page-about .tl__marks {
    flex-direction: column;
    flex-wrap: nowrap;
    gap: 30px;
    padding-left: 22px;
    position: relative;
  }

  .page-about .tl__marks::before {
    content: "";
    position: absolute;
    left: 5px;
    top: 6px;
    bottom: 6px;
    width: 1px;
    background: linear-gradient(180deg, var(--green), var(--line) 88%);
  }

  .page-about .tl__marks a::before {
    content: "";
    position: absolute;
    left: -22px;
    top: 50%;
    width: 11px;
    height: 11px;
    margin-top: -5.5px;
    border: 1px solid var(--line);
    border-radius: 50%;
    background: var(--ink-900);
    transition: background var(--dur) var(--ease), border-color var(--dur) var(--ease);
  }

  .page-about .tl__marks a:hover::before,
  .page-about .tl__marks a:focus-visible::before {
    background: var(--lime);
    border-color: var(--lime);
  }

  .page-about .about-roots__grid {
    grid-template-columns: minmax(0, 1fr) minmax(0, 1fr);
    gap: clamp(40px, 6vw, 88px);
    align-items: start;
  }
}

@media (prefers-reduced-motion: reduce) {
  .page-about [data-reveal] {
    opacity: 1;
    transform: none;
    transition: none;
  }

  .page-about .stage__mark,
  .page-about .stage__note,
  .page-about .tl__marks a::before {
    transition: none;
  }

  .page-about .stage:hover .stage__mark {
    transform: none;
  }
}