.page-about {
  --about-rail-w: 208px;
  --about-gap: 56px;
}

/* ---------- 面包屑位置 ---------- */
.page-about .tb-breadcrumb {
  padding-top: 20px;
  padding-bottom: 16px;
}

/* ---------- 首屏 ---------- */
.page-about .about-hero {
  position: relative;
  overflow: hidden;
  border-bottom: 1px solid var(--line);
}

.page-about .about-hero__media {
  position: absolute;
  inset: 0;
}

.page-about .about-hero__media img {
  display: block;
  width: 100%;
  height: 100%;
  object-fit: cover;
  opacity: 0.42;
}

.page-about .about-hero__media::after {
  content: "";
  position: absolute;
  inset: 0;
  background:
    linear-gradient(180deg, rgba(6, 35, 28, 0.55) 0%, rgba(6, 35, 28, 0.86) 56%, var(--bg) 100%),
    radial-gradient(120% 90% at 84% 12%, rgba(37, 242, 199, 0.12) 0%, rgba(6, 35, 28, 0) 62%);
}

.page-about .about-hero__body {
  position: relative;
  z-index: 1;
  display: flex;
  flex-direction: column;
  justify-content: flex-end;
  min-height: min(74vh, 600px);
  padding-top: 72px;
  padding-bottom: 56px;
}

.page-about .about-hero__body h1 {
  margin: 12px 0 0;
  font-family: var(--font-head);
  font-size: clamp(32px, 5.4vw, 66px);
  font-weight: 800;
  line-height: 1.12;
  letter-spacing: -0.02em;
  color: var(--ink);
  max-width: 18em;
}

.page-about .about-hero__lead {
  margin: 20px 0 0;
  max-width: 46em;
  color: var(--muted);
  font-size: clamp(15px, 1.5vw, 17px);
  line-height: 1.8;
}

.page-about .about-hero__facts {
  list-style: none;
  margin: 32px 0 0;
  padding: 18px 0 0;
  border-top: 1px solid var(--line);
  display: flex;
  flex-wrap: wrap;
  gap: 12px 34px;
}

.page-about .about-hero__fact {
  display: flex;
  align-items: baseline;
  gap: 8px;
  font-size: 13px;
  color: var(--muted);
}

.page-about .about-hero__fact .tb-num {
  font-size: 22px;
  font-weight: 700;
  color: var(--ink);
  letter-spacing: -0.01em;
}

/* ---------- 走廊骨架 ---------- */
.page-about .about-corridor {
  display: grid;
  grid-template-columns: 1fr;
  gap: 28px;
  padding-top: 56px;
  padding-bottom: 88px;
}

.page-about .about-rail__title {
  margin: 0 0 12px;
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: 0.22em;
  text-transform: uppercase;
  color: var(--muted);
}

.page-about .about-rail__list {
  list-style: none;
  margin: 0;
  padding: 0 0 6px;
  display: flex;
  gap: 8px;
  overflow-x: auto;
  scrollbar-width: none;
}

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

.page-about .about-rail__link {
  display: flex;
  align-items: center;
  gap: 9px;
  padding: 8px 14px;
  border: 1px solid var(--line-soft);
  border-radius: 999px;
  color: var(--muted);
  text-decoration: none;
  font-size: 13px;
  white-space: nowrap;
  transition: color 0.18s ease, border-color 0.18s ease, background-color 0.18s ease;
}

.page-about .about-rail__code {
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: 0.1em;
  color: var(--muted);
  transition: color 0.18s ease;
}

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

.page-about .about-rail__link.is-current {
  color: var(--cyan);
  border-color: var(--cyan);
  background: var(--cyan-soft);
}

.page-about .about-rail__link.is-current .about-rail__code {
  color: var(--cyan);
}

.page-about .about-flow {
  display: flex;
  flex-direction: column;
  gap: 76px;
  min-width: 0;
}

/* ---------- 章节通用 ---------- */
.page-about .about-stage {
  position: relative;
  scroll-margin-top: calc(var(--header-h) + 28px);
}

.page-about .about-stage__note {
  display: none;
}

.page-about .about-stage__head {
  display: flex;
  align-items: baseline;
  flex-wrap: wrap;
  gap: 12px;
  padding-bottom: 16px;
  border-bottom: 1px solid var(--line);
  margin-bottom: 24px;
}

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

.page-about .about-stage__head h2 {
  margin: 0;
  font-family: var(--font-head);
  font-size: clamp(23px, 3.2vw, 36px);
  font-weight: 800;
  line-height: 1.24;
  letter-spacing: -0.015em;
  color: var(--ink);
}

.page-about .about-prose p {
  margin: 0 0 15px;
  font-size: 15.5px;
  line-height: 1.8;
  color: var(--ink);
}

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

.page-about .about-tail {
  margin: 22px 0 0;
  padding-left: 16px;
  border-left: 2px solid var(--orange);
  font-size: 14px;
  line-height: 1.8;
  color: var(--muted);
}

/* ---------- 说明牌 ---------- */
.page-about .about-plates {
  display: grid;
  grid-template-columns: 1fr;
  gap: 16px;
  margin-top: 30px;
}

.page-about .about-plate {
  padding: 22px 22px 18px;
  background: var(--panel);
  border: 1px solid var(--line-soft);
  transition: border-color 0.18s ease, background-color 0.18s ease;
}

.page-about .about-plate:hover {
  border-color: var(--line);
}

.page-about .about-plate__no {
  margin: 0 0 10px;
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: 0.16em;
  text-transform: uppercase;
  color: var(--cyan);
}

.page-about .about-plate__title {
  margin: 0 0 10px;
  font-family: var(--font-head);
  font-size: 18px;
  font-weight: 700;
  line-height: 1.42;
  color: var(--ink);
}

.page-about .about-plate p {
  margin: 0;
  font-size: 14px;
  line-height: 1.8;
  color: var(--muted);
}

.page-about .about-plate__meta {
  margin-top: 16px !important;
  padding-top: 11px;
  border-top: 1px solid var(--line-soft);
  font-family: var(--font-mono);
  font-size: 11px !important;
  letter-spacing: 0.04em;
  color: var(--muted) !important;
}

/* ---------- 四道工序 ---------- */
.page-about .about-process {
  list-style: none;
  margin: 28px 0 0;
  padding: 0;
  display: grid;
  grid-template-columns: 1fr;
  gap: 14px;
}

.page-about .about-process__item {
  position: relative;
  padding: 26px 20px 16px;
  background: var(--panel);
  border: 1px solid var(--line-soft);
  transition: border-color 0.2s ease, background-color 0.2s ease;
}

.page-about .about-process__item::before {
  content: "";
  position: absolute;
  top: -1px;
  left: 20px;
  width: 34px;
  height: 2px;
  background: var(--cyan);
}

.page-about .about-process__item:hover {
  border-color: var(--line);
  background: rgba(37, 242, 199, 0.04);
}

.page-about .about-process__idx {
  display: block;
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: 0.18em;
  color: var(--muted);
}

.page-about .about-process__title {
  margin: 8px 0 8px;
  font-family: var(--font-head);
  font-size: 20px;
  font-weight: 800;
  letter-spacing: 0.02em;
  color: var(--ink);
}

.page-about .about-process__item p {
  margin: 0;
  font-size: 13.5px;
  line-height: 1.78;
  color: var(--muted);
}

.page-about .about-process__reveal {
  display: grid;
  grid-template-rows: 0fr;
  transition: grid-template-rows 0.28s ease;
  margin-top: 0;
}

.page-about .about-process__reveal > div {
  overflow: hidden;
  min-height: 0;
  display: flex;
  flex-wrap: wrap;
  gap: 6px 14px;
  padding-top: 0;
  transition: padding-top 0.28s ease;
}

.page-about .about-process__item:hover .about-process__reveal,
.page-about .about-process__item:focus-within .about-process__reveal {
  grid-template-rows: 1fr;
}

.page-about .about-process__item:hover .about-process__reveal > div,
.page-about .about-process__item:focus-within .about-process__reveal > div {
  padding-top: 14px;
}

@media (hover: none) {
  .page-about .about-process__reveal {
    grid-template-rows: 1fr;
  }
  .page-about .about-process__reveal > div {
    padding-top: 14px;
  }
}

.page-about .about-process__k {
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: 0.05em;
  color: var(--orange);
  border: 1px solid rgba(255, 138, 61, 0.32);
  padding: 3px 8px;
}

/* ---------- 图片通用 ---------- */
.page-about .about-figure {
  margin: 30px 0 0;
  border: 1px solid var(--line-soft);
  background: var(--panel);
  overflow: hidden;
}

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

.page-about .about-figure--square img {
  max-height: 520px;
}

.page-about .about-figure__cap {
  padding: 12px 16px 14px;
  border-top: 1px solid var(--line-soft);
  font-size: 12.5px;
  line-height: 1.7;
  color: var(--muted);
}

/* ---------- 团队数字与节点 ---------- */
.page-about .about-mix {
  display: grid;
  grid-template-columns: 1fr;
  gap: 0;
  margin-top: 28px;
  border-top: 1px solid var(--line-soft);
}

.page-about .about-mix__item {
  display: flex;
  align-items: baseline;
  gap: 12px;
  padding: 15px 4px;
  border-bottom: 1px solid var(--line-soft);
  font-size: 13.5px;
  color: var(--muted);
}

.page-about .about-mix__item .tb-num {
  min-width: 5.5em;
  font-size: 20px;
  font-weight: 700;
  color: var(--ink);
  letter-spacing: -0.01em;
}

.page-about .about-nodes {
  list-style: none;
  margin: 24px 0 0;
  padding: 0;
  border-top: 1px solid var(--line-soft);
}

.page-about .about-nodes__row {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 8px 18px;
  padding: 14px 2px;
  border-bottom: 1px solid var(--line-soft);
  transition: background-color 0.18s ease;
}

.page-about .about-nodes__row:hover {
  background: var(--cyan-soft);
}

.page-about .about-nodes__name {
  font-family: var(--font-head);
  font-size: 15px;
  font-weight: 700;
  color: var(--ink);
  min-width: 6em;
}

.page-about .about-nodes__role {
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.03em;
  color: var(--muted);
}

/* ---------- 发展线 ---------- */
.page-about .about-line {
  list-style: none;
  margin: 28px 0 0;
  padding: 0 0 0 26px;
  position: relative;
}

.page-about .about-line::before {
  content: "";
  position: absolute;
  left: 5px;
  top: 6px;
  bottom: 18px;
  width: 1px;
  background: var(--line);
}

.page-about .about-line__item {
  position: relative;
  padding-bottom: 30px;
}

.page-about .about-line__item:last-child {
  padding-bottom: 0;
}

.page-about .about-line__item::before {
  content: "";
  position: absolute;
  left: -25px;
  top: 6px;
  width: 9px;
  height: 9px;
  border-radius: 50%;
  background: var(--bg);
  border: 1px solid var(--cyan);
}

.page-about .about-line__item:last-child::before {
  background: var(--cyan);
  box-shadow: 0 0 12px rgba(37, 242, 199, 0.55);
}

.page-about .about-line__when {
  margin: 0 0 6px;
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: 0.14em;
  color: var(--cyan);
}

.page-about .about-line__title {
  margin: 0 0 6px;
  font-family: var(--font-head);
  font-size: 18px;
  font-weight: 700;
  line-height: 1.42;
  color: var(--ink);
}

.page-about .about-line__item p {
  margin: 0;
  font-size: 14px;
  line-height: 1.78;
  color: var(--muted);
}

.page-about .about-line__item .about-line__title + p {
  margin-top: 0;
}

/* ---------- 质量指标 ---------- */
.page-about .about-metrics {
  list-style: none;
  margin: 28px 0 0;
  padding: 0;
  display: grid;
  grid-template-columns: 1fr;
  border-top: 1px solid var(--line-soft);
}

.page-about .about-metrics__item {
  display: grid;
  gap: 3px;
  padding: 18px 16px;
  border-bottom: 1px solid var(--line-soft);
  transition: background-color 0.18s ease;
}

.page-about .about-metrics__item:hover {
  background: var(--cyan-soft);
}

.page-about .about-metrics__val {
  font-size: 24px;
  font-weight: 700;
  letter-spacing: -0.01em;
  color: var(--ink);
}

.page-about .about-metrics__name {
  font-family: var(--font-head);
  font-size: 14px;
  font-weight: 700;
  color: var(--ink);
}

.page-about .about-metrics__hint {
  font-family: var(--font-mono);
  font-size: 11.5px;
  letter-spacing: 0.02em;
  color: var(--muted);
  opacity: 0.68;
  transition: opacity 0.18s ease, color 0.18s ease;
}

.page-about .about-metrics__item:hover .about-metrics__hint {
  opacity: 1;
  color: var(--cyan);
}

.page-about .about-cta {
  margin-top: 26px;
  padding: 22px 20px;
  background: var(--panel);
  border: 1px solid var(--line-soft);
  border-left: 2px solid var(--orange);
  display: flex;
  flex-direction: column;
  gap: 16px;
  align-items: flex-start;
}

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

/* ---------- 页尾延伸索引 ---------- */
.page-about .about-next {
  border-top: 1px solid var(--line);
  background: linear-gradient(180deg, rgba(11, 51, 41, 0.55) 0%, rgba(4, 26, 22, 0.9) 100%);
}

.page-about .about-next .tb-container {
  padding-top: 52px;
  padding-bottom: 64px;
}

.page-about .about-next__title {
  margin: 0 0 22px;
  font-family: var(--font-head);
  font-size: clamp(20px, 2.4vw, 26px);
  font-weight: 800;
  letter-spacing: -0.01em;
  color: var(--ink);
}

.page-about .about-next__list {
  list-style: none;
  margin: 0;
  padding: 0;
  display: grid;
  grid-template-columns: 1fr;
  gap: 12px;
}

.page-about .about-next__link {
  display: grid;
  gap: 6px;
  padding: 18px 18px 20px;
  border: 1px solid var(--line-soft);
  background: rgba(6, 35, 28, 0.5);
  text-decoration: none;
  transition: border-color 0.18s ease, background-color 0.18s ease, transform 0.18s ease;
}

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

.page-about .about-next__k {
  font-family: var(--font-head);
  font-size: 16px;
  font-weight: 700;
  color: var(--ink);
}

.page-about .about-next__d {
  font-size: 13px;
  line-height: 1.7;
  color: var(--muted);
}

/* ---------- 中等屏幕 ---------- */
@media (min-width: 640px) {
  .page-about .about-plates {
    grid-template-columns: repeat(2, 1fr);
  }

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

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

  .page-about .about-metrics__item {
    border-right: 1px solid var(--line-soft);
  }

  .page-about .about-metrics__item:nth-child(2n) {
    border-right: 0;
  }

  .page-about .about-mix__item {
    padding-left: 0;
  }

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

/* ---------- 桌面：左侧走廊轴 ---------- */
@media (min-width: 960px) {
  .page-about .about-corridor {
    grid-template-columns: var(--about-rail-w) minmax(0, 1fr);
    gap: var(--about-gap);
    align-items: start;
    padding-top: 72px;
    padding-bottom: 104px;
  }

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

  .page-about .about-rail__title {
    padding-left: 14px;
  }

  .page-about .about-rail__list {
    flex-direction: column;
    gap: 0;
    overflow: visible;
    padding-bottom: 0;
    border-left: 1px solid var(--line);
  }

  .page-about .about-rail__link {
    border: 0;
    border-left: 2px solid transparent;
    border-radius: 0;
    padding: 11px 14px;
    white-space: normal;
  }

  .page-about .about-rail__link.is-current {
    border-left-color: var(--cyan);
  }

  .page-about .about-flow {
    gap: 92px;
  }

  .page-about .about-next__list {
    grid-template-columns: repeat(4, 1fr);
  }
}

/* ---------- 宽屏：竖排展签 ---------- */
@media (min-width: 1180px) {
  .page-about .about-stage__note {
    display: block;
    position: absolute;
    left: -46px;
    top: 76px;
    writing-mode: vertical-rl;
    font-family: var(--font-mono);
    font-size: 10.5px;
    letter-spacing: 0.28em;
    text-transform: uppercase;
    color: var(--muted);
    opacity: 0.7;
  }
}

/* ---------- 动效降级 ---------- */
@media (prefers-reduced-motion: reduce) {
  .page-about *,
  .page-about *::before,
  .page-about *::after {
    transition-duration: 0.01ms !important;
    animation-duration: 0.01ms !important;
  }
}
<<<END>>>