.page-about {
  position: relative;
  background: var(--ink);
  color: var(--cream);
  padding-bottom: 88px;
}

/* ---------- 首屏 ---------- */
.page-about .about-hero {
  padding: 24px 0 0;
}

.page-about .about-hero h1 {
  font-family: var(--font-narrow);
  font-size: var(--h1);
  font-weight: 900;
  line-height: 1.08;
  letter-spacing: -0.02em;
  margin: 10px 0 20px;
  max-width: 19ch;
}

.page-about .about-hero .lede {
  max-width: 42em;
  color: rgba(242, 239, 230, 0.84);
}

.page-about .about-figures {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 1px;
  background: var(--line);
  border: 1px solid var(--line);
  margin: 34px 0 0;
  padding: 0;
}

.page-about .about-figure {
  background: var(--ink);
  padding: 16px 18px 18px;
  margin: 0;
}

.page-about .about-figure dt {
  font-size: 13px;
  letter-spacing: 0.04em;
  color: var(--mist);
  margin: 0 0 10px;
}

.page-about .about-figure dd {
  margin: 0;
  font-family: var(--font-mono);
  font-size: var(--num);
  line-height: 1;
  letter-spacing: 0.01em;
  color: var(--cyan);
}

.page-about .about-figure dd span {
  font-family: var(--font-sans);
  font-size: 13px;
  letter-spacing: 0;
  color: var(--mist);
  margin-left: 6px;
}

/* ---------- 双栏布局 ---------- */
.page-about .about-layout {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 30px;
  margin-top: 52px;
}

/* ---------- 章节跳转 ---------- */
.page-about .about-rail {
  border-top: 1px solid var(--line);
  padding-top: 14px;
}

.page-about .about-rail__title {
  margin: 0 0 12px;
  font-size: 12px;
  letter-spacing: 0.22em;
  color: var(--rock);
}

.page-about .about-rail__list {
  list-style: none;
  margin: 0;
  padding: 0 0 4px;
  display: flex;
  gap: 20px;
  overflow-x: auto;
  scrollbar-width: none;
}

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

.page-about .about-rail__link {
  display: inline-block;
  white-space: nowrap;
  font-size: 15px;
  line-height: 1.6;
  color: var(--rock);
  text-decoration: none;
  border-bottom: 1px solid transparent;
  transition: color 0.18s var(--ease), border-color 0.18s var(--ease);
}

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

/* ---------- 正文区块 ---------- */
.page-about .about-body {
  min-width: 0;
}

.page-about .about-block {
  padding: 42px 0;
  border-top: 1px solid var(--line-soft);
  scroll-margin-top: calc(var(--nav-h-condensed) + 20px);
}

.page-about .about-block:first-child {
  border-top: 0;
  padding-top: 4px;
}

.page-about .about-block__index {
  margin: 0 0 12px;
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.22em;
  color: var(--orange);
}

.page-about .about-block h2 {
  font-family: var(--font-narrow);
  font-size: var(--h2);
  font-weight: 900;
  line-height: 1.18;
  letter-spacing: -0.02em;
  margin: 0 0 20px;
  max-width: 24ch;
}

.page-about .about-block p {
  max-width: 38em;
  font-size: var(--body);
  line-height: 1.78;
  color: rgba(242, 239, 230, 0.82);
  margin: 0 0 16px;
}

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

/* ---------- 覆盖范围分层 ---------- */
.page-about .about-tiers {
  margin: 26px 0 0;
  border-top: 1px solid var(--line);
}

.page-about .about-tier {
  border-bottom: 1px solid var(--line);
}

.page-about .about-tier__summary {
  display: flex;
  align-items: baseline;
  gap: 14px;
  cursor: pointer;
  padding: 15px 0;
  list-style: none;
}

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

.page-about .about-tier__summary::marker {
  content: "";
}

.page-about .about-tier__summary::after {
  content: "＋";
  margin-left: auto;
  font-family: var(--font-mono);
  font-size: 14px;
  color: var(--cyan);
}

.page-about .about-tier[open] .about-tier__summary::after {
  content: "－";
}

.page-about .about-tier__mark {
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.06em;
  color: var(--cyan);
  border: 1px solid var(--cyan-line);
  padding: 2px 6px;
}

.page-about .about-tier__name {
  font-family: var(--font-narrow);
  font-size: 19px;
  font-weight: 800;
  letter-spacing: -0.01em;
  color: var(--cream);
}

.page-about .about-tier__note {
  margin-left: 16px;
  font-size: 13px;
  color: var(--rock);
  white-space: nowrap;
}

.page-about .about-tier p {
  margin: 0 0 18px;
  max-width: 34em;
  font-size: 16px;
  line-height: 1.78;
  color: rgba(242, 239, 230, 0.74);
}

/* ---------- 配图 ---------- */
.page-about .about-media {
  margin: 30px 0 0;
}

.page-about .about-media img {
  display: block;
  width: 100%;
  max-width: 100%;
  height: auto;
  border: 1px solid var(--line);
  background: var(--ink-2);
  object-fit: cover;
}

.page-about .about-media figcaption {
  margin-top: 12px;
  padding-left: 12px;
  border-left: 2px solid var(--cyan-line);
  max-width: 40em;
  font-size: 14px;
  line-height: 1.7;
  color: var(--mist);
}

/* ---------- 数据流程 ---------- */
.page-about .about-flow {
  list-style: none;
  margin: 30px 0 0;
  padding: 0;
  display: grid;
  grid-template-columns: minmax(0, 1fr);
}

.page-about .about-flow__item {
  border-top: 3px solid var(--cyan);
  padding: 20px 0 24px;
}

.page-about .about-flow__num {
  display: block;
  font-family: var(--font-mono);
  font-size: 13px;
  letter-spacing: 0.16em;
  color: var(--orange);
  margin-bottom: 12px;
}

.page-about .about-flow__item h3 {
  font-family: var(--font-narrow);
  font-size: var(--h3);
  font-weight: 800;
  letter-spacing: -0.01em;
  margin: 0 0 10px;
}

.page-about .about-flow__item p {
  margin: 0;
  max-width: none;
  font-size: 15px;
  line-height: 1.75;
  color: rgba(242, 239, 230, 0.74);
}

/* ---------- 团队分工 ---------- */
.page-about .about-team {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 1px;
  background: var(--line);
  border: 1px solid var(--line);
  margin: 28px 0 22px;
}

.page-about .about-team__group {
  background: var(--ink-2);
  padding: 22px 20px 24px;
}

.page-about .about-team__group h3 {
  font-family: var(--font-narrow);
  font-size: 19px;
  font-weight: 800;
  letter-spacing: -0.01em;
  color: var(--cream);
  margin: 0 0 12px;
}

.page-about .about-team__group h3::after {
  content: "";
  display: block;
  width: 28px;
  height: 2px;
  margin-top: 10px;
  background: var(--clay);
}

.page-about .about-team__group p {
  margin: 0;
  max-width: none;
  font-size: 15px;
  line-height: 1.75;
  color: rgba(242, 239, 230, 0.76);
}

/* ---------- 发展历程 ---------- */
.page-about .about-block--timeline {
  position: relative;
  overflow: hidden;
}

.page-about .about-timeline__bg {
  position: absolute;
  inset: 0;
  z-index: 0;
  opacity: 0.16;
  pointer-events: none;
}

.page-about .about-timeline__bg img {
  width: 100%;
  height: 100%;
  max-width: 100%;
  object-fit: cover;
  filter: saturate(0.4) contrast(1.1);
  -webkit-mask-image: linear-gradient(160deg, rgba(0, 0, 0, 0.95), rgba(0, 0, 0, 0) 72%);
  mask-image: linear-gradient(160deg, rgba(0, 0, 0, 0.95), rgba(0, 0, 0, 0) 72%);
}

.page-about .about-block--timeline > *:not(.about-timeline__bg) {
  position: relative;
  z-index: 1;
}

.page-about .about-timeline {
  list-style: none;
  margin: 30px 0 0;
  padding: 0 0 0 28px;
  border-left: 2px solid var(--cyan-line);
}

.page-about .about-timeline > li {
  position: relative;
  padding-bottom: 22px;
}

.page-about .about-timeline > li:last-child {
  padding-bottom: 0;
}

.page-about .about-timeline > li::before {
  content: "";
  position: absolute;
  left: -33px;
  top: 8px;
  width: 10px;
  height: 10px;
  background: var(--orange);
  transform: rotate(45deg);
}

.page-about .about-step__summary {
  display: flex;
  align-items: baseline;
  gap: 14px;
  cursor: pointer;
  padding: 2px 0 4px;
  list-style: none;
}

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

.page-about .about-step__summary::marker {
  content: "";
}

.page-about .about-step__summary::after {
  content: "＋";
  margin-left: auto;
  font-family: var(--font-mono);
  font-size: 13px;
  color: var(--cyan);
}

.page-about .about-step[open] > .about-step__summary::after {
  content: "－";
}

.page-about .about-step__year {
  font-family: var(--font-mono);
  font-size: 20px;
  line-height: 1;
  letter-spacing: 0.04em;
  color: var(--orange);
}

.page-about .about-step__title {
  font-family: var(--font-narrow);
  font-size: 18px;
  font-weight: 800;
  letter-spacing: -0.01em;
  color: var(--cream);
}

.page-about .about-step p {
  margin: 6px 0 0;
  max-width: 34em;
  font-size: 15.5px;
  line-height: 1.78;
  color: rgba(242, 239, 230, 0.76);
}

/* ---------- 服务与备案 ---------- */
.page-about .about-facts {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 1px;
  background: var(--line);
  border: 1px solid var(--line);
  margin: 28px 0 0;
}

.page-about .about-fact {
  background: var(--ink);
  padding: 15px 18px;
  display: flex;
  align-items: baseline;
  justify-content: space-between;
  gap: 16px;
}

.page-about .about-fact__k {
  font-size: 13px;
  letter-spacing: 0.04em;
  color: var(--rock);
  white-space: nowrap;
}

.page-about .about-fact__v {
  font-family: var(--font-mono);
  font-size: 15px;
  color: var(--cream);
  text-align: right;
  word-break: break-word;
}

/* ---------- 延伸入口 ---------- */
.page-about .about-next {
  margin-top: 54px;
  padding: 34px 22px 30px;
  border: 1px solid var(--line);
  background-color: var(--ink-2);
  background-image: linear-gradient(rgba(107, 122, 116, 0.13) 1px, transparent 1px),
    linear-gradient(90deg, rgba(107, 122, 116, 0.13) 1px, transparent 1px);
  background-size: 28px 28px;
  position: relative;
}

.page-about .about-next::before {
  content: "";
  position: absolute;
  top: 0;
  left: 0;
  width: 96px;
  height: 3px;
  background: var(--orange);
}

.page-about .about-next h2 {
  font-family: var(--font-narrow);
  font-size: var(--h2);
  font-weight: 900;
  line-height: 1.18;
  letter-spacing: -0.02em;
  margin: 0 0 14px;
}

.page-about .about-next p {
  margin: 0 0 24px;
  max-width: 42em;
  font-size: var(--body);
  line-height: 1.75;
  color: rgba(242, 239, 230, 0.8);
}

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

.page-about .about-next__link {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 16px;
  padding: 17px 18px;
  background: rgba(6, 42, 36, 0.78);
  color: var(--cream);
  font-size: 15.5px;
  line-height: 1.6;
  text-decoration: none;
  transition: background 0.18s var(--ease), color 0.18s var(--ease);
}

.page-about .about-next__link:hover,
.page-about .about-next__link:focus-visible {
  background: var(--cyan-soft);
  color: var(--cyan);
}

.page-about .about-next__arrow {
  font-family: var(--font-mono);
  color: var(--cyan);
  flex: none;
}

/* ---------- 断点 ---------- */
@media (max-width: 600px) {
  .page-about .about-tier__note {
    display: none;
  }

  .page-about .about-step__summary {
    gap: 10px;
  }

  .page-about .about-step__title {
    font-size: 16px;
  }
}

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

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

  .page-about .about-facts {
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }

  .page-about .about-next__list {
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }

  .page-about .about-next {
    padding: 40px 34px 36px;
  }
}

@media (min-width: 768px) {
  .page-about .about-flow {
    grid-template-columns: repeat(4, minmax(0, 1fr));
    column-gap: 28px;
    margin-top: 34px;
  }

  .page-about .about-flow__item {
    padding: 20px 0 8px;
  }
}

@media (min-width: 960px) {
  .page-about .about-hero {
    padding-top: 40px;
  }

  .page-about .about-layout {
    grid-template-columns: 208px minmax(0, 1fr);
    gap: 64px;
    margin-top: 68px;
  }

  .page-about .about-rail {
    position: sticky;
    top: calc(var(--nav-h-condensed) + 24px);
    border-top: 0;
    border-left: 2px solid var(--cyan-line);
    padding: 4px 0 4px 18px;
  }

  .page-about .about-rail__list {
    flex-direction: column;
    gap: 14px;
    overflow: visible;
    padding: 0;
  }

  .page-about .about-rail__link {
    white-space: normal;
    font-size: 14px;
  }

  .page-about .about-block {
    padding: 54px 0;
  }

  .page-about .about-block h2 {
    max-width: 26ch;
  }
}
<<<END>>>