.page-about {
  --about-spine-w: 232px;
  display: block;
  background: var(--ink-900);
  color: var(--text);
  font-family: var(--font-sans);
}

/* ---------- 面包屑 ---------- */
.page-about .about-crumbs {
  padding: clamp(16px, 2.6vw, 26px) 0 0;
}

/* ---------- 首屏 ---------- */
.page-about .about-hero {
  position: relative;
  border-bottom: 1px solid var(--line);
  background:
    radial-gradient(110% 82% at 88% 6%, rgba(34, 225, 214, 0.16), transparent 62%),
    radial-gradient(88% 70% at 2% 100%, rgba(255, 181, 69, 0.10), transparent 60%),
    linear-gradient(180deg, var(--ink-800) 0%, var(--ink-900) 100%);
}

.page-about .about-hero__inner {
  display: grid;
  gap: clamp(26px, 4vw, 52px);
  padding: clamp(22px, 4vw, 44px) 0 clamp(36px, 5vw, 72px);
}

.page-about .about-hero__title {
  margin: 14px 0 0;
  font-size: clamp(29px, 6.2vw, 62px);
  line-height: 1.06;
  letter-spacing: -0.012em;
  font-weight: 700;
}

.page-about .about-hero__lede {
  margin: 18px 0 0;
  max-width: 54ch;
  color: var(--text-soft);
  font-size: clamp(15px, 1.6vw, 17px);
  line-height: 1.82;
}

.page-about .about-hero__links {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
  margin-top: 26px;
}

.page-about .about-hero__visual {
  display: grid;
  gap: var(--gap);
  align-content: end;
}

.page-about .about-hero__plate {
  position: relative;
  border: 1px solid var(--line);
  border-radius: var(--r-lg);
  background: linear-gradient(152deg, var(--ink-700), var(--ink-800));
  padding: clamp(20px, 3vw, 30px);
}

.page-about .about-hero__plate::after {
  content: "";
  position: absolute;
  right: -10px;
  bottom: -10px;
  width: 58%;
  height: 58%;
  border-right: 1px solid var(--line);
  border-bottom: 1px solid var(--line);
  border-radius: 0 0 var(--r-lg) 0;
  pointer-events: none;
}

.page-about .about-hero__plate-kicker {
  margin: 0;
  font-size: 12px;
  letter-spacing: 0.2em;
  text-transform: uppercase;
  color: var(--muted);
}

.page-about .about-hero__year {
  margin: 10px 0 0;
  font-family: var(--font-mono);
  font-size: clamp(52px, 12vw, 104px);
  line-height: 0.94;
  font-weight: 700;
  letter-spacing: -0.03em;
  color: var(--amber);
}

.page-about .about-hero__plate-note {
  margin: 12px 0 0;
  font-size: 13px;
  color: var(--text-soft);
}

.page-about .about-hero__stats {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 10px;
  margin: 0;
}

.page-about .about-hero__stat {
  border: 1px solid var(--line);
  border-radius: var(--r-sm);
  background: rgba(15, 23, 48, 0.72);
  padding: 12px 14px;
}

.page-about .about-hero__stat dt {
  font-size: 12px;
  letter-spacing: 0.1em;
  color: var(--muted);
}

.page-about .about-hero__stat dd {
  margin: 6px 0 0;
  font-family: var(--font-mono);
  font-size: 19px;
  color: var(--text);
}

.page-about .about-hero__stat dd .num {
  color: var(--cyan);
  font-size: 24px;
}

/* ---------- 主体：左侧索引 + 右侧长文 ---------- */
.page-about .about-body {
  display: grid;
  gap: clamp(22px, 3.4vw, 40px);
  padding: clamp(30px, 5vw, 62px) 0 clamp(40px, 6vw, 82px);
}

.page-about .about-spine {
  border: 1px solid var(--line);
  border-radius: var(--r-md);
  background: var(--ink-800);
  padding: 16px 16px 14px;
}

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

.page-about .about-spine__list {
  list-style: none;
  margin: 12px 0 0;
  padding: 0;
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 2px;
}

.page-about .about-spine__list a {
  display: flex;
  align-items: baseline;
  gap: 9px;
  padding: 9px 8px;
  border-left: 2px solid transparent;
  border-radius: var(--r-sm);
  color: var(--text-soft);
  text-decoration: none;
  font-size: 14px;
  transition: background 0.16s var(--ease), color 0.16s var(--ease), border-color 0.16s var(--ease);
}

.page-about .about-spine__list a:hover,
.page-about .about-spine__list a:focus-visible {
  background: var(--ink-700);
  color: var(--text);
  border-left-color: var(--cyan);
}

.page-about .about-spine__num {
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.14em;
  color: var(--cyan);
}

.page-about .about-spine__foot {
  margin: 14px 0 0;
  padding-top: 12px;
  border-top: 1px solid var(--line);
  font-size: 13px;
  color: var(--muted);
}

.page-about .about-spine__foot a {
  color: var(--cyan);
  text-decoration: none;
  border-bottom: 1px solid rgba(34, 225, 214, 0.4);
}

.page-about .about-flow {
  display: grid;
  gap: clamp(34px, 5vw, 64px);
  min-width: 0;
}

/* ---------- 章节 ---------- */
.page-about .about-chapter {
  min-width: 0;
  border-top: 1px solid var(--line);
  padding-top: clamp(22px, 3vw, 34px);
  scroll-margin-top: 100px;
}

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

.page-about .about-chapter__head {
  display: flex;
  align-items: baseline;
  flex-wrap: wrap;
  gap: 12px;
  margin-bottom: 16px;
}

.page-about .about-chapter__index {
  flex: none;
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.2em;
  color: var(--cyan);
  padding: 3px 9px;
  border: 1px solid var(--line);
  border-radius: 999px;
  background: rgba(22, 33, 74, 0.7);
}

.page-about .about-chapter__title {
  margin: 0;
  font-size: clamp(21px, 3vw, 30px);
  line-height: 1.26;
}

.page-about .about-chapter__body {
  max-width: 68ch;
  color: var(--text-soft);
  font-size: 16px;
  line-height: 1.86;
}

.page-about .about-chapter__body p {
  margin: 0 0 14px;
}

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

.page-about .about-chapter__body a {
  color: var(--cyan);
  text-decoration: none;
  border-bottom: 1px solid rgba(34, 225, 214, 0.4);
}

.page-about .about-chapter__body--tight {
  margin-top: 18px;
  font-size: 15px;
}

.page-about .about-chapter__lede {
  margin: 0 0 18px;
  color: var(--text-soft);
  font-size: 15px;
  line-height: 1.82;
}

/* ---------- 数字锚点 ---------- */
.page-about .about-figures {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(158px, 1fr));
  gap: var(--gap);
  margin-top: 24px;
}

.page-about .about-figures__item {
  border: 1px solid var(--line);
  border-left: 3px solid var(--cyan);
  border-radius: var(--r-sm);
  background: var(--ink-800);
  padding: 16px 18px;
}

.page-about .about-figures__item .stat__num {
  margin: 0;
  font-family: var(--font-mono);
  font-size: clamp(30px, 4.6vw, 46px);
  line-height: 1;
  letter-spacing: -0.02em;
  color: var(--text);
}

.page-about .about-figures__item .stat__label {
  margin: 9px 0 0;
  font-size: 12px;
  letter-spacing: 0.14em;
  color: var(--muted);
}

/* ---------- 图片容器 ---------- */
.page-about .about-chapter__media {
  margin: 0 0 22px;
  border: 1px solid var(--line);
  border-radius: var(--r-md);
  overflow: hidden;
  background: var(--ink-800);
}

.page-about .about-chapter__media img,
.page-about .about-split__media img {
  display: block;
  width: 100%;
  height: auto;
  max-width: 100%;
  object-fit: cover;
}

.page-about .media__cap {
  padding: 10px 14px;
  border-top: 1px solid var(--line);
  font-size: 12px;
  letter-spacing: 0.08em;
  color: var(--muted);
}

/* ---------- 时间轴横向带 ---------- */
.page-about .about-timeline {
  margin-top: 22px;
}

.page-about .about-timeline .rail__track {
  display: flex;
  gap: var(--gap);
  list-style: none;
  margin: 0;
  padding: 0 0 14px;
  overflow-x: auto;
  scroll-snap-type: x mandatory;
  -webkit-overflow-scrolling: touch;
}

.page-about .about-timeline .rail__item {
  flex: 0 0 min(80%, 320px);
  scroll-snap-align: start;
  border: 1px solid var(--line);
  border-radius: var(--r-md);
  background: linear-gradient(160deg, var(--ink-700), var(--ink-800));
  padding: 18px 20px 20px;
}

.page-about .about-timeline .rail__item:nth-child(4) {
  border-color: rgba(255, 181, 69, 0.45);
}

.page-about .about-stage__kicker {
  margin: 0;
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.16em;
  color: var(--amber);
}

.page-about .about-stage__title {
  margin: 10px 0 8px;
  font-size: 17px;
  line-height: 1.4;
  color: var(--text);
}

.page-about .about-stage__text {
  margin: 0;
  font-size: 14px;
  line-height: 1.78;
  color: var(--text-soft);
}

.page-about .about-stage__num {
  display: block;
  margin-top: 16px;
  padding-top: 12px;
  border-top: 1px dashed var(--line);
  font-family: var(--font-mono);
  font-size: 24px;
  letter-spacing: -0.01em;
  color: var(--ice);
}

/* ---------- 两栏错层 ---------- */
.page-about .about-split {
  display: grid;
  gap: clamp(20px, 3vw, 32px);
  align-items: start;
}

.page-about .about-split__media {
  margin: 0;
  border: 1px solid var(--line);
  border-radius: var(--r-md);
  overflow: hidden;
  background: var(--ink-800);
}

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

/* ---------- 折叠面板 ---------- */
.page-about .about-fold {
  border: 1px solid var(--line);
  border-radius: var(--r-sm);
  background: var(--ink-800);
  margin: 0 0 10px;
  overflow: hidden;
}

.page-about .about-fold > summary {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 12px;
  padding: 14px 18px;
  cursor: pointer;
  list-style: none;
  font-size: 15px;
  font-weight: 600;
  color: var(--text);
  transition: background 0.16s var(--ease), color 0.16s var(--ease);
}

.page-about .about-fold > summary::-webkit-details-marker {
  display: none;
}

.page-about .about-fold > summary::after {
  content: "+";
  flex: none;
  font-family: var(--font-mono);
  font-size: 18px;
  line-height: 1;
  color: var(--cyan);
}

.page-about .about-fold > summary:hover {
  background: var(--ink-700);
}

.page-about .about-fold[open] > summary {
  color: var(--cyan);
  border-bottom: 1px solid var(--line);
}

.page-about .about-fold[open] > summary::after {
  content: "–";
}

.page-about .about-fold p {
  margin: 0;
  padding: 14px 18px 16px;
  font-size: 14.5px;
  line-height: 1.8;
  color: var(--text-soft);
}

/* ---------- 合作层级 ---------- */
.page-about .about-tiers {
  display: grid;
  gap: 14px;
}

.page-about .about-tier {
  position: relative;
  overflow: hidden;
  border: 1px solid var(--line);
  border-radius: var(--r-sm);
  background: var(--ink-800);
  padding: 16px 18px;
}

.page-about .about-tier::before {
  content: "";
  position: absolute;
  left: 0;
  top: 0;
  bottom: 0;
  width: var(--tier-w, 38%);
  background: linear-gradient(90deg, rgba(34, 225, 214, 0.20), rgba(34, 225, 214, 0));
  pointer-events: none;
}

.page-about .about-tier--2::before {
  --tier-w: 70%;
  background: linear-gradient(90deg, rgba(79, 195, 255, 0.22), rgba(79, 195, 255, 0));
}

.page-about .about-tier--3::before {
  --tier-w: 100%;
  background: linear-gradient(90deg, rgba(255, 181, 69, 0.20), rgba(255, 181, 69, 0));
}

.page-about .about-tier__name,
.page-about .about-tier__text,
.page-about .about-tier__meta {
  position: relative;
}

.page-about .about-tier__name {
  margin: 0;
  font-size: 16px;
  color: var(--text);
}

.page-about .about-tier__text {
  margin: 8px 0 0;
  font-size: 14.5px;
  line-height: 1.78;
  color: var(--text-soft);
}

.page-about .about-tier__meta {
  margin: 10px 0 0;
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.1em;
  color: var(--amber);
}

/* ---------- 表格 ---------- */
.page-about .about-table-wrap {
  margin-top: 22px;
  border: 1px solid var(--line);
  border-radius: var(--r-md);
  background: var(--ink-800);
  overflow-x: auto;
}

.page-about .about-table {
  width: 100%;
  min-width: 460px;
  border-collapse: collapse;
  font-size: 14.5px;
}

.page-about .about-table__caption {
  padding: 14px 18px;
  text-align: left;
  font-size: 12px;
  letter-spacing: 0.16em;
  color: var(--muted);
  border-bottom: 1px solid var(--line);
}

.page-about .about-table th,
.page-about .about-table td {
  padding: 13px 18px;
  text-align: left;
  border-bottom: 1px solid rgba(42, 58, 107, 0.6);
}

.page-about .about-table th {
  font-size: 12px;
  letter-spacing: 0.14em;
  color: var(--muted);
  background: rgba(22, 33, 74, 0.6);
}

.page-about .about-table td {
  color: var(--text-soft);
}

.page-about .about-table tbody tr:last-child td {
  border-bottom: 0;
}

.page-about .about-table td:first-child {
  color: var(--text);
}

.page-about .about-table a {
  color: var(--cyan);
  text-decoration: none;
  border-bottom: 1px solid rgba(34, 225, 214, 0.35);
}

/* ---------- 服务四步 ---------- */
.page-about .about-steps {
  list-style: none;
  margin: 22px 0 0;
  padding: 0;
  display: grid;
  gap: var(--gap);
}

.page-about .about-steps li {
  border: 1px solid var(--line);
  border-radius: var(--r-md);
  background: var(--ink-800);
  padding: 18px 20px;
}

.page-about .about-steps__no {
  display: inline-block;
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: 0.16em;
  color: var(--ink-1000);
  background: var(--cyan);
  border-radius: 3px;
  padding: 3px 7px;
}

.page-about .about-steps h3 {
  margin: 13px 0 7px;
  font-size: 16px;
  color: var(--text);
}

.page-about .about-steps p {
  margin: 0;
  font-size: 14.5px;
  line-height: 1.78;
  color: var(--text-soft);
}

/* ---------- 收尾 ---------- */
.page-about .about-cta {
  border-top: 1px solid var(--line);
  background:
    radial-gradient(92% 130% at 10% 0%, rgba(34, 225, 214, 0.14), transparent 60%),
    radial-gradient(80% 120% at 92% 100%, rgba(255, 181, 69, 0.10), transparent 58%),
    var(--ink-800);
}

.page-about .about-cta__inner {
  display: grid;
  gap: 22px;
  padding: clamp(34px, 5vw, 66px) 0;
}

.page-about .about-cta__title {
  margin: 0;
  font-size: clamp(22px, 3.2vw, 34px);
  line-height: 1.24;
}

.page-about .about-cta__text {
  margin: 14px 0 0;
  max-width: 56ch;
  color: var(--text-soft);
  font-size: 15.5px;
  line-height: 1.82;
}

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

.page-about .about-cta__contact {
  grid-column: 1 / -1;
  margin: 0;
  padding-top: 18px;
  border-top: 1px solid var(--line);
  font-family: var(--font-mono);
  font-size: 12.5px;
  letter-spacing: 0.04em;
  color: var(--muted);
}

/* ---------- 响应式 ---------- */
@media (min-width: 520px) {
  .page-about .about-hero__stats {
    grid-template-columns: repeat(3, minmax(0, 1fr));
  }

  .page-about .about-timeline .rail__item {
    flex: 0 0 min(58%, 340px);
  }
}

@media (min-width: 760px) {
  .page-about .about-steps {
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }
}

@media (min-width: 880px) {
  .page-about .about-split {
    grid-template-columns: minmax(0, 0.88fr) minmax(0, 1.12fr);
  }

  .page-about .about-split--reverse {
    grid-template-columns: minmax(0, 1.15fr) minmax(0, 0.85fr);
  }

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

@media (min-width: 960px) {
  .page-about .about-hero__inner {
    grid-template-columns: minmax(0, 1.08fr) minmax(0, 0.92fr);
    align-items: end;
  }

  .page-about .about-body {
    grid-template-columns: var(--about-spine-w) minmax(0, 1fr);
    gap: clamp(36px, 5vw, 76px);
    align-items: start;
  }

  .page-about .about-spine {
    position: sticky;
    top: 96px;
  }

  .page-about .about-spine__list {
    grid-template-columns: 1fr;
  }
}

@media (prefers-reduced-motion: reduce) {
  .page-about *,
  .page-about *::before,
  .page-about *::after {
    animation-duration: 0.01ms !important;
    animation-iteration-count: 1 !important;
    transition-duration: 0.01ms !important;
    scroll-behavior: auto !important;
  }
}
<<<END>>>