.page-about {
  --about-rail: 208px;
  --about-node: var(--amber);
  color: var(--paper-100);
}

/* ---------- 面包屑与首屏 ---------- */
.page-about .crumbs {
  margin: 0;
  padding-block: clamp(.9rem, 2vw, 1.4rem) 0;
}

.page-about .about-hero {
  padding-block: clamp(1.2rem, 3vw, 2rem) clamp(2rem, 4vw, 3.2rem);
}

.page-about .about-hero__grid {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: clamp(1.5rem, 4vw, 3rem);
  align-items: end;
}

.page-about .about-hero__title {
  margin: .55rem 0 0;
  font-size: clamp(1.9rem, 6.2vw, 3.35rem);
  line-height: 1.08;
  letter-spacing: .012em;
  font-weight: 800;
  color: var(--paper-100);
  text-wrap: balance;
}

.page-about .about-hero__lede {
  margin-top: 1rem;
  max-width: 46ch;
  color: rgba(242, 232, 213, .82);
}

.page-about .about-hero__actions {
  display: flex;
  flex-wrap: wrap;
  gap: .7rem;
  margin-top: 1.5rem;
}

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

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

/* ---------- 概况数字条 ---------- */
.page-about .about-stats {
  list-style: none;
  margin: clamp(1.6rem, 4vw, 2.6rem) 0 0;
  padding: 0;
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 1px;
  background: var(--line-strong);
  border: 1px solid var(--line-strong);
}

.page-about .about-stats li {
  display: flex;
  flex-direction: column;
  gap: .25rem;
  padding: .95rem 1rem 1.15rem;
  background: var(--ink-800);
}

.page-about .about-stats__num {
  font-size: clamp(1.5rem, 4vw, 2.1rem);
  line-height: 1;
  color: var(--orange);
  letter-spacing: -.01em;
}

.page-about .about-stats__label {
  font-size: .84rem;
  letter-spacing: .04em;
  color: var(--slate);
}

/* ---------- 主体两栏 ---------- */
.page-about .about-body {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: clamp(1.5rem, 4vw, 3rem);
  padding-block: clamp(2rem, 5vw, 3.5rem);
}

.page-about .about-rail__label {
  margin: 0 0 .7rem;
  font-size: .74rem;
  letter-spacing: .2em;
  text-transform: uppercase;
  color: var(--slate);
}

.page-about .about-rail__list {
  position: relative;
  list-style: none;
  margin: 0;
  padding: 0;
  display: flex;
  flex-wrap: wrap;
  gap: .45rem 1.1rem;
}

.page-about .about-rail__list a {
  display: inline-flex;
  align-items: baseline;
  gap: .45rem;
  padding: .18rem 0;
  font-size: .9rem;
  color: var(--slate);
  text-decoration: none;
  border-bottom: 1px solid transparent;
  transition: color var(--speed) ease, border-color var(--speed) ease;
}

.page-about .about-rail__list a .mono {
  font-size: .78rem;
  color: var(--orange);
}

.page-about .about-rail__list a:hover,
.page-about .about-rail__list a:focus-visible {
  color: var(--paper-100);
  border-color: var(--orange);
}

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

/* ---------- 章节 ---------- */
.page-about .about-section {
  padding-block: clamp(1.6rem, 4vw, 2.6rem);
  border-top: 1px solid var(--line);
}

.page-about .about-section:first-child {
  padding-top: 0;
  border-top: 0;
}

.page-about .about-note {
  margin: 1.4rem 0 0;
  padding-left: .9rem;
  border-left: 2px solid var(--amber);
  font-size: .93rem;
  color: rgba(242, 232, 213, .72);
}

/* ---------- 起点卡片 ---------- */
.page-about .about-origin {
  margin-top: 1.5rem;
}

.page-about .about-origin .card-body p {
  margin: 0;
}

/* ---------- 版本时间线 ---------- */
.page-about .about-track {
  margin-top: 1.8rem;
}

.page-about .track-list {
  position: relative;
  list-style: none;
  margin: 0;
  padding: 1.9rem 0 0;
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 1.4rem 1rem;
}

.page-about .track-list::before {
  content: "";
  position: absolute;
  top: .65rem;
  left: 0;
  right: 0;
  height: 1px;
  background: repeating-linear-gradient(90deg, rgba(217, 164, 65, .6) 0 7px, transparent 7px 15px);
  pointer-events: none;
}

.page-about .track-node {
  position: relative;
  padding-top: .5rem;
  border-top: 1px solid var(--line);
}

.page-about .track-node::before {
  content: "";
  position: absolute;
  top: -1.32rem;
  left: 0;
  width: 9px;
  height: 9px;
  border-radius: 50%;
  background: var(--about-node);
  box-shadow: 0 0 0 3px var(--ink-900);
  transition: transform var(--speed) ease;
}

.page-about .track-node:nth-child(n + 5) {
  --about-node: var(--celadon);
}

.page-about .track-node:hover::before {
  transform: scale(1.35);
}

.page-about .track-name {
  margin: 0;
  font-size: 1rem;
  letter-spacing: .05em;
  color: var(--paper-100);
}

.page-about .track-meta {
  margin: .2rem 0 .5rem;
  font-size: .82rem;
  color: var(--amber);
  letter-spacing: .06em;
}

.page-about .track-node:nth-child(n + 5) .track-meta {
  color: var(--celadon);
}

.page-about .track-desc {
  margin: 0;
  font-size: .87rem;
  line-height: 1.7;
  color: rgba(242, 232, 213, .7);
}

.page-about .track-more {
  margin-top: .6rem;
  border-top: 1px dashed var(--line);
  padding-top: .5rem;
}

.page-about .track-more summary {
  cursor: pointer;
  font-size: .78rem;
  letter-spacing: .04em;
  color: var(--slate);
  list-style: none;
  transition: color var(--speed) ease;
}

.page-about .track-more summary::-webkit-details-marker {
  display: none;
}

.page-about .track-more summary::after {
  content: " +";
  color: var(--orange);
}

.page-about .track-more[open] summary::after {
  content: " −";
}

.page-about .track-more summary:hover,
.page-about .track-more summary:focus-visible {
  color: var(--paper-100);
}

.page-about .track-more ul {
  margin: .5rem 0 0;
  padding-left: 1.05rem;
  font-size: .8rem;
  line-height: 1.72;
  color: rgba(242, 232, 213, .66);
}

.page-about .about-timeline-figure {
  margin: clamp(1.6rem, 4vw, 2.4rem) 0 0;
}

.page-about .about-timeline-figure img,
.page-about .about-team__media img {
  display: block;
  width: 100%;
  height: auto;
  object-fit: cover;
}

/* ---------- 团队 ---------- */
.page-about .about-team {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: clamp(1.25rem, 3vw, 2rem);
  margin-top: 1.6rem;
}

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

.page-about .about-team__copy .index-item {
  align-items: flex-start;
  padding-block: .85rem;
}

.page-about .about-team__copy .index-text {
  line-height: 1.78;
  color: rgba(242, 232, 213, .82);
}

.page-about .about-team__copy .index-text strong {
  display: block;
  margin-bottom: .2rem;
  color: var(--paper-100);
  letter-spacing: .04em;
}

/* ---------- 覆盖与协作 ---------- */
.page-about .about-reach {
  margin-top: 1.6rem;
}

.page-about .about-reach .card-body p {
  margin: 0;
  font-size: .92rem;
  line-height: 1.75;
}

.page-about .about-reach .eyebrow {
  margin: 0 0 .35rem;
  font-size: .7rem;
}

/* ---------- 标识与更新 ---------- */
.page-about .about-section--mark {
  padding-bottom: clamp(2rem, 5vw, 3rem);
}

.page-about .mark-band {
  margin-top: 1.6rem;
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 1.2rem;
  padding: clamp(1.1rem, 3vw, 1.7rem);
  background: linear-gradient(135deg, var(--ink-800), var(--ink-700));
  border: 1px solid var(--line-strong);
  border-left: 4px solid var(--orange);
  box-shadow: var(--shadow-paper);
}

.page-about .mark-band__stamp {
  align-self: start;
  margin: 0;
  font-size: clamp(.9rem, 2.4vw, 1.05rem);
  letter-spacing: .14em;
  color: var(--orange);
  padding: .45rem .7rem;
  border: 1px dashed rgba(242, 107, 33, .55);
  white-space: nowrap;
}

.page-about .mark-band__list {
  margin: 0;
}

.page-about .mark-band__row {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: .15rem;
  padding: .7rem 0;
  border-top: 1px solid var(--line);
}

.page-about .mark-band__row:first-child {
  border-top: 0;
  padding-top: 0;
}

.page-about .mark-band__row .kv-value {
  color: rgba(242, 232, 213, .84);
  font-size: .92rem;
  line-height: 1.7;
}

.page-about .mark-band__row .kv-value a {
  color: var(--celadon);
  text-decoration: underline;
  text-underline-offset: 3px;
}

.page-about .mark-band__row .kv-value a:hover,
.page-about .mark-band__row .kv-value a:focus-visible {
  color: var(--paper-100);
}

.page-about .about-cta {
  margin-top: 1.8rem;
  padding-top: 1.4rem;
  border-top: 1px dashed var(--line);
  display: grid;
  gap: 1rem;
}

.page-about .about-cta__text {
  margin: 0;
  max-width: 52ch;
  font-size: .95rem;
  color: rgba(242, 232, 213, .78);
}

.page-about .about-cta__links {
  display: flex;
  flex-wrap: wrap;
  gap: .7rem;
}

/* ---------- 响应式 ---------- */
@media (min-width: 620px) {
  .page-about .about-stats {
    grid-template-columns: repeat(4, minmax(0, 1fr));
  }

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

  .page-about .mark-band__row {
    grid-template-columns: 110px minmax(0, 1fr);
    align-items: baseline;
    gap: 1rem;
  }
}

@media (min-width: 900px) {
  .page-about .about-hero__grid {
    grid-template-columns: minmax(0, 1.05fr) minmax(0, .95fr);
  }

  .page-about .about-team {
    grid-template-columns: minmax(0, .85fr) minmax(0, 1.15fr);
    align-items: start;
  }

  .page-about .about-cta {
    grid-template-columns: minmax(0, 1fr) auto;
    align-items: center;
  }

  .page-about .about-cta__links {
    justify-content: flex-end;
  }
}

@media (min-width: 1000px) {
  .page-about .about-body {
    grid-template-columns: var(--about-rail) minmax(0, 1fr);
    align-items: start;
  }

  .page-about .about-rail {
    position: sticky;
    top: 5.5rem;
    padding-right: 1.2rem;
  }

  .page-about .about-rail__list {
    flex-direction: column;
    flex-wrap: nowrap;
    gap: .5rem;
    padding-left: 1.1rem;
  }

  .page-about .about-rail__list::before {
    content: "";
    position: absolute;
    left: .22rem;
    top: .45rem;
    bottom: .45rem;
    width: 1px;
    background: linear-gradient(180deg, var(--orange), rgba(242, 107, 33, .06));
  }

  .page-about .about-rail__list a::before {
    content: "";
    position: absolute;
    left: -1.1rem;
    top: .62rem;
    width: 5px;
    height: 5px;
    border-radius: 50%;
    background: var(--slate);
    transform: translateX(-2px);
    transition: background var(--speed) ease;
  }

  .page-about .about-rail__list a:hover::before,
  .page-about .about-rail__list a:focus-visible::before {
    background: var(--orange);
  }

  .page-about .track-list {
    grid-template-columns: repeat(6, minmax(0, 1fr));
    gap: 1rem .85rem;
  }
}
<<<END>>>