.page-about {
  --about-border: 1px solid var(--line);
  --about-rail-dot-y: 27px;
  display: block;
}

/* ---------- 面包屑 ---------- */
.page-about .breadcrumb {
  padding: 22px 0 0;
}

.page-about .breadcrumb-list {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 8px;
  margin: 0;
  padding: 0;
  list-style: none;
  font-family: var(--font-head);
  font-size: var(--t-12);
  letter-spacing: .08em;
  text-transform: uppercase;
  color: var(--muted);
}

.page-about .breadcrumb-item:not(:last-child)::after {
  content: "/";
  margin-left: 8px;
  color: var(--dim);
}

.page-about .breadcrumb-link {
  color: var(--muted);
  text-decoration: none;
  transition: color 140ms var(--ease);
}

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

/* ---------- 首屏 ---------- */
.page-about .about-hero {
  padding: 30px 0 4px;
}

.page-about .about-hero__inner {
  display: grid;
  gap: 30px;
}

.page-about .about-hero__text .eyebrow {
  margin: 0 0 12px;
  font-family: var(--font-head);
  font-size: var(--t-12);
  font-weight: 700;
  letter-spacing: .18em;
  text-transform: uppercase;
  color: var(--gold);
}

.page-about .about-hero__text .page-title {
  margin: 0;
  font-size: var(--t-38);
  line-height: 1.06;
  letter-spacing: -.01em;
  color: var(--paper);
}

.page-about .about-hero__text .lede {
  margin: 18px 0 0;
  max-width: 52ch;
  font-family: var(--font-body);
  font-size: var(--t-19);
  line-height: 1.78;
  color: var(--paper);
}

.page-about .about-hero__rule {
  display: block;
  width: 88px;
  height: 6px;
  margin-top: 26px;
  background: var(--lime);
  transform: skewX(-18deg);
}

.page-about .about-hero__figure {
  margin: 0;
  border: var(--about-border);
  background: var(--panel);
  overflow: hidden;
}

.page-about .about-hero__figure img {
  display: block;
  width: 100%;
  height: auto;
  aspect-ratio: 7 / 4;
  object-fit: cover;
}

/* ---------- 通用文本 ---------- */
.page-about .about-copy {
  margin: 0 0 16px;
  font-family: var(--font-body);
  font-size: 16px;
  line-height: 1.85;
  color: var(--muted);
}

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

.page-about .about-copy--lead {
  font-size: var(--t-19);
  line-height: 1.8;
  color: var(--paper);
}

.page-about .section-title {
  margin: 0 0 18px;
  font-family: var(--font-head);
  font-size: var(--t-30);
  line-height: 1.16;
  letter-spacing: -.01em;
  color: var(--paper);
}

.page-about .eyebrow {
  margin: 0 0 10px;
  font-family: var(--font-head);
  font-size: var(--t-12);
  font-weight: 700;
  letter-spacing: .18em;
  text-transform: uppercase;
  color: var(--gold);
}

/* ---------- 起点 ---------- */
.page-about .about-origin {
  padding: 68px 0 56px;
}

.page-about .about-origin__inner {
  display: grid;
  gap: 0;
}

.page-about .about-origin__inner::before {
  content: "";
  display: block;
  height: 6px;
  width: 120px;
  background: var(--grad-contrast);
  transform: skewX(-18deg);
  margin-bottom: 26px;
}

/* ---------- 四层内容 ---------- */
.page-about .about-stack {
  padding: 58px 0 68px;
  background: var(--panel);
  border-top: var(--about-border);
  border-bottom: var(--about-border);
}

.page-about .about-stack__grid {
  gap: 40px;
  align-items: start;
}

.page-about .about-stack__list {
  list-style: none;
  margin: 26px 0 0;
  padding: 0;
  display: grid;
  gap: 0;
}

.page-about .about-stack__item {
  display: grid;
  grid-template-columns: 40px minmax(0, 1fr);
  gap: 14px;
  padding: 16px 0;
  border-top: var(--about-border);
}

.page-about .about-stack__item:last-child {
  border-bottom: var(--about-border);
}

.page-about .about-stack__idx {
  padding-top: 3px;
  font-family: var(--font-num);
  font-weight: 800;
  font-size: var(--t-15);
  letter-spacing: .04em;
  color: var(--gold);
}

.page-about .about-stack__h {
  margin: 0 0 6px;
  font-family: var(--font-head);
  font-size: var(--t-19);
  letter-spacing: .01em;
  color: var(--paper);
}

.page-about .about-stack__item .about-copy {
  margin: 0;
  font-size: var(--t-15);
}

.page-about .about-stack__note {
  margin-top: 24px;
  font-size: var(--t-15);
}

.page-about .about-stack__figure {
  margin: 0;
  border: var(--about-border);
  background: var(--bg);
  overflow: hidden;
}

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

/* ---------- 收录范围 ---------- */
.page-about .about-scale {
  padding: 62px 0 70px;
}

.page-about .about-scale__lede {
  max-width: 62ch;
}

.page-about .about-scale__band {
  margin-top: 32px;
  padding: 28px 0 22px;
  border-top: var(--about-border);
  border-bottom: var(--about-border);
}

.page-about .about-scale__items {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 26px 16px;
}

.page-about .about-scale__label {
  display: block;
  margin-bottom: 10px;
  font-family: var(--font-head);
  font-size: var(--t-12);
  letter-spacing: .1em;
  text-transform: uppercase;
  color: var(--muted);
}

.page-about .about-scale__value {
  display: flex;
  align-items: baseline;
  gap: 6px;
  font-family: var(--font-num);
  font-weight: 800;
  font-size: var(--t-38);
  line-height: 1;
  color: var(--lime);
}

.page-about .about-scale__unit {
  font-family: var(--font-body);
  font-size: var(--t-15);
  font-weight: 400;
  color: var(--muted);
}

.page-about .about-scale__rail {
  display: block;
  margin-top: 26px;
  height: 3px;
  background: var(--line);
  overflow: hidden;
}

.page-about .about-scale__rail .contrast-bar__fill {
  display: block;
  width: 0;
  height: 100%;
  background: var(--grad-contrast);
  transition: width 640ms var(--ease);
}

.page-about .about-scale__band.is-grown .contrast-bar__fill {
  width: var(--v, 100%);
}

.page-about .about-scale__note {
  margin-top: 24px;
  font-size: var(--t-15);
}

/* ---------- 团队 ---------- */
.page-about .about-team {
  padding: 62px 0 58px;
  background: var(--panel);
  border-top: var(--about-border);
  border-bottom: var(--about-border);
}

.page-about .about-team__lede {
  max-width: 58ch;
}

.page-about .about-team__cols {
  margin-top: 30px;
  border-top: var(--about-border);
}

.page-about .about-team__col {
  padding: 18px 0;
  border-bottom: var(--about-border);
}

.page-about .about-team__sum {
  display: flex;
  align-items: baseline;
  justify-content: space-between;
  gap: 14px;
  cursor: pointer;
  list-style: none;
}

.page-about .about-team__sum::-webkit-details-marker {
  display: none;
}

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

.page-about .about-team__role {
  font-family: var(--font-head);
  font-size: var(--t-19);
  letter-spacing: .02em;
  color: var(--paper);
}

.page-about .about-team__count {
  font-family: var(--font-num);
  font-weight: 800;
  font-size: var(--t-24);
  color: var(--gold);
  white-space: nowrap;
}

.page-about .about-team__body {
  padding-top: 10px;
}

.page-about .about-team__body .about-copy {
  margin: 0;
  font-size: var(--t-15);
}

/* ---------- 版本沿革 ---------- */
.page-about .about-version {
  padding: 64px 0 70px;
}

.page-about .about-version__head {
  display: grid;
  gap: 32px;
  align-items: start;
}

.page-about .about-version__intro .section-title {
  max-width: 22ch;
}

.page-about .about-version__figure {
  margin: 0;
  border: var(--about-border);
  background: var(--panel);
  overflow: hidden;
}

.page-about .about-version__figure img {
  display: block;
  width: 100%;
  height: auto;
  aspect-ratio: 1 / 1;
  object-fit: cover;
}

.page-about .about-version__rail-wrap {
  margin-top: 42px;
  border-top: var(--about-border);
  border-bottom: var(--about-border);
  overflow-x: auto;
  overflow-y: hidden;
  scrollbar-width: thin;
  scrollbar-color: var(--dim) transparent;
  -webkit-overflow-scrolling: touch;
}

.page-about .about-version__rail-wrap::-webkit-scrollbar {
  height: 6px;
}

.page-about .about-version__rail-wrap::-webkit-scrollbar-thumb {
  background: var(--dim);
}

.page-about .about-version__rail-wrap::-webkit-scrollbar-track {
  background: transparent;
}

.page-about .about-version__rail {
  position: relative;
  display: flex;
  align-items: flex-start;
  min-width: max-content;
  margin: 0;
  padding: 34px clamp(20px, 4vw, 60px) 30px;
  list-style: none;
}

.page-about .about-version__rail::before {
  content: "";
  position: absolute;
  left: 0;
  right: 0;
  top: 61px;
  height: 1px;
  background: var(--line);
}

.page-about .about-version__item {
  margin-right: 14px;
}

.page-about .about-version__item:nth-child(n + 5) {
  margin-right: 30px;
}

.page-about .about-version__item:nth-child(n + 9) {
  margin-right: 56px;
}

.page-about .about-version__item:last-child {
  margin-right: 20px;
}

.page-about .about-version__node {
  width: 190px;
}

.page-about .about-version__sum {
  position: relative;
  display: flex;
  flex-direction: column;
  align-items: flex-start;
  gap: 8px;
  padding-top: 22px;
  cursor: pointer;
  list-style: none;
}

.page-about .about-version__sum::-webkit-details-marker {
  display: none;
}

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

.page-about .about-version__dot {
  position: absolute;
  top: 22px;
  left: 0;
  width: 10px;
  height: 10px;
  background: var(--gold);
  transform: rotate(45deg);
  transition: background-color 140ms var(--ease);
}

.page-about .about-version__item:last-child .about-version__dot {
  top: 20px;
  width: 14px;
  height: 14px;
  background: var(--lime);
}

.page-about .about-version__meta {
  display: flex;
  align-items: baseline;
  gap: 10px;
}

.page-about .about-version__v {
  font-family: var(--font-num);
  font-weight: 800;
  font-size: var(--t-15);
  letter-spacing: .04em;
  color: var(--gold);
}

.page-about .about-version__item:last-child .about-version__v {
  color: var(--lime);
}

.page-about .about-version__y {
  font-family: var(--font-num);
  font-size: var(--t-12);
  color: var(--dim);
}

.page-about .about-version__t {
  font-family: var(--font-head);
  font-size: var(--t-15);
  line-height: 1.45;
  color: var(--paper);
}

.page-about .about-version__desc {
  margin: 12px 0 0;
  padding-left: 12px;
  border-left: var(--about-border);
  font-family: var(--font-body);
  font-size: var(--t-15);
  line-height: 1.7;
  color: var(--muted);
}

/* ---------- 备案 ---------- */
.page-about .about-legal {
  padding: 18px 0 84px;
}

.page-about .about-legal__panel {
  display: grid;
  gap: 24px;
  padding: 26px 22px;
  background: var(--glass);
  border: var(--about-border);
}

.page-about .about-legal__h {
  margin: 0 0 12px;
  font-family: var(--font-head);
  font-size: var(--t-24);
  letter-spacing: .01em;
  color: var(--paper);
}

.page-about .about-legal__links {
  display: flex;
  flex-wrap: wrap;
  gap: 18px;
  margin: 18px 0 0;
  font-family: var(--font-head);
  font-size: var(--t-12);
  letter-spacing: .1em;
  text-transform: uppercase;
}

.page-about .about-legal__list {
  display: grid;
  gap: 0;
  margin: 0;
}

.page-about .about-legal__list > div {
  display: grid;
  grid-template-columns: 88px minmax(0, 1fr);
  gap: 12px;
  align-items: baseline;
  padding-top: 12px;
  border-top: var(--about-border);
}

.page-about .about-legal__list dt {
  font-family: var(--font-head);
  font-size: var(--t-12);
  letter-spacing: .1em;
  text-transform: uppercase;
  color: var(--muted);
}

.page-about .about-legal__list dd {
  margin: 0;
  font-family: var(--font-num);
  font-size: var(--t-15);
  line-height: 1.6;
  color: var(--paper);
  word-break: break-word;
}

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

  .page-about .about-legal__list {
    gap: 4px;
  }
}

/* ---------- 桌面 ---------- */
@media (min-width: 900px) {
  .page-about .breadcrumb {
    padding-top: 28px;
  }

  .page-about .about-hero {
    padding: 52px 0 6px;
  }

  .page-about .about-hero__inner {
    grid-template-columns: minmax(0, 7fr) minmax(0, 5fr);
    gap: 52px;
    align-items: center;
  }

  .page-about .about-hero__text .page-title {
    font-size: var(--t-48);
  }

  .page-about .about-hero__figure {
    transform: translateY(20px);
  }

  .page-about .section-title {
    font-size: var(--t-38);
  }

  .page-about .about-origin {
    padding: 96px 0 76px;
  }

  .page-about .about-origin__inner {
    grid-template-columns: minmax(0, 4fr) minmax(0, 8fr);
    gap: 48px;
    align-items: start;
  }

  .page-about .about-origin__inner::before {
    grid-column: 1 / -1;
    margin-bottom: 32px;
  }

  .page-about .about-stack {
    padding: 80px 0 88px;
  }

  .page-about .about-stack__grid {
    gap: 56px;
  }

  .page-about .about-scale {
    padding: 84px 0 92px;
  }

  .page-about .about-team {
    padding: 82px 0 78px;
  }

  .page-about .about-team__cols {
    display: grid;
    grid-template-columns: repeat(3, minmax(0, 1fr));
    border-top: 0;
    gap: 0;
  }

  .page-about .about-team__col {
    padding: 4px 30px;
    border-bottom: 0;
    border-left: var(--about-border);
  }

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

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

  .page-about .about-team__sum {
    pointer-events: none;
  }

  .page-about .about-team__body {
    padding-top: 14px;
  }

  .page-about .about-version {
    padding: 86px 0 92px;
  }

  .page-about .about-version__head {
    grid-template-columns: minmax(0, 7fr) minmax(0, 4fr);
    gap: 60px;
  }

  .page-about .about-version__intro .section-title {
    font-size: var(--t-38);
  }

  .page-about .about-version__rail-wrap {
    margin-top: 54px;
  }

  .page-about .about-legal {
    padding: 30px 0 108px;
  }

  .page-about .about-legal__panel {
    grid-template-columns: minmax(0, 1fr) minmax(0, 1.15fr);
    gap: 48px;
    padding: 36px 34px;
  }
}

/* ---------- 宽屏 ---------- */
@media (min-width: 1280px) {
  .page-about .about-hero__text .page-title {
    font-size: var(--t-60);
  }

  .page-about .about-origin {
    padding: 112px 0 88px;
  }
}

/* ---------- 动效偏好 ---------- */
@media (prefers-reduced-motion: reduce) {
  .page-about .about-scale__rail .contrast-bar__fill,
  .page-about .about-version__dot {
    transition: none;
  }
}

.page-about {
  --v: 1rem;
}