.page-about {
  --about-rail: 176px;
  --about-sec-gap: clamp(20px, 3.5vw, 56px);
  --about-y: clamp(34px, 5vw, 66px);
  --about-lead-w: 34em;
}

.page-about .about-wrap {
  padding-bottom: clamp(36px, 6vw, 88px);
}

/* ---------- 首屏 ---------- */
.page-about .about-hero {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: clamp(26px, 4vw, 52px);
  padding: clamp(18px, 2.6vw, 34px) 0 var(--about-y);
  border-bottom: 1px solid var(--rule);
}

.page-about .about-hero-copy {
  min-width: 0;
}

.page-about .about-hero h1 {
  margin: 0.32em 0 0;
  font-family: var(--font-display);
  font-size: clamp(1.85rem, 4.4vw, 3.25rem);
  line-height: 1.12;
  letter-spacing: -0.012em;
  color: var(--ink-blue);
  max-width: 15em;
}

.page-about .about-lead {
  margin: 1.15em 0 0;
  max-width: var(--about-lead-w);
  font-size: clamp(0.98rem, 1.05vw, 1.06rem);
  line-height: 1.85;
  color: var(--grey);
}

.page-about .about-stats {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 1px;
  margin-top: clamp(22px, 3vw, 34px);
  border: 1px solid var(--rule);
  border-radius: 12px;
  overflow: hidden;
  background: var(--rule);
}

.page-about .about-stat {
  display: flex;
  flex-direction: column;
  gap: 4px;
  padding: 14px 14px 16px;
  background: var(--paper);
}

.page-about .about-stat-num {
  font-family: var(--font-mono);
  font-size: clamp(1.2rem, 2.1vw, 1.55rem);
  line-height: 1.1;
  letter-spacing: -0.02em;
  color: var(--ink-blue);
}

.page-about .about-stat-label {
  font-size: 0.76rem;
  line-height: 1.45;
  color: var(--grey);
}

.page-about .about-hero-figure {
  position: relative;
  margin: 0;
  padding: 12px;
  border: 1px solid var(--rule);
  border-radius: var(--card-radius);
  background: linear-gradient(170deg, rgba(215, 240, 239, 0.6), rgba(251, 250, 247, 0) 72%), var(--paper);
}

.page-about .about-hero-figure::before,
.page-about .about-hero-figure::after {
  content: "";
  position: absolute;
  width: 15px;
  height: 15px;
  border: 2px solid var(--cyan);
}

.page-about .about-hero-figure::before {
  top: -1px;
  left: -1px;
  border-right: 0;
  border-bottom: 0;
  border-top-left-radius: 6px;
}

.page-about .about-hero-figure::after {
  right: -1px;
  bottom: -1px;
  border-left: 0;
  border-top: 0;
  border-bottom-right-radius: 6px;
}

.page-about .about-hero-figure img {
  display: block;
  width: 100%;
  height: auto;
  aspect-ratio: 3 / 2;
  object-fit: cover;
  border-radius: calc(var(--card-radius) - 7px);
  background: var(--sage);
}

.page-about .about-hero-figure .media-caption {
  margin: 10px 4px 0;
}

/* ---------- 编号章节 ---------- */
.page-about .about-sec {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: clamp(14px, 2.2vw, 26px);
  padding: var(--about-y) 0;
  border-bottom: 1px solid var(--rule);
}

.page-about .about-sec-rail {
  display: flex;
  align-items: baseline;
  gap: 12px;
  min-width: 0;
}

.page-about .about-sec-num {
  font-family: var(--font-mono);
  font-size: clamp(1.6rem, 3.2vw, 2.6rem);
  line-height: 1;
  letter-spacing: -0.04em;
  color: var(--ink-blue);
}

.page-about .about-sec-anno {
  margin: 0;
  font-family: var(--font-mono);
  font-size: 0.72rem;
  letter-spacing: 0.14em;
  color: var(--cyan);
}

.page-about .about-sec-body {
  min-width: 0;
}

.page-about .about-sec-body h2 {
  margin: 0 0 0.55em;
  color: var(--ink-blue);
}

.page-about .about-p {
  margin: 0 0 1em;
  max-width: var(--about-lead-w);
  line-height: 1.85;
  color: var(--ink);
}

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

/* ---------- 品牌主张三栏 ---------- */
.page-about .about-three {
  list-style: none;
  margin: clamp(20px, 3vw, 30px) 0 0;
  padding: 0;
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 12px;
}

.page-about .about-three li {
  padding: 18px 18px 20px;
  background: var(--paper);
  border: 1px solid var(--rule);
  border-radius: 14px;
  transition: border-color 0.28s var(--ease), transform 0.28s var(--ease);
}

.page-about .about-three li::before {
  content: "";
  display: block;
  width: 22px;
  height: 2px;
  margin-bottom: 12px;
  background: var(--cyan);
}

.page-about .about-three li:hover {
  border-color: var(--cyan);
  transform: translateY(-2px);
}

.page-about .about-three-title {
  margin: 0 0 0.45em;
  font-size: 1rem;
  color: var(--ink-blue);
}

.page-about .about-three li p {
  margin: 0;
  font-size: 0.88rem;
  line-height: 1.7;
  color: var(--grey);
}

/* ---------- 发展历程 ---------- */
.page-about .about-timeline-fig {
  margin: 0 0 clamp(18px, 2.6vw, 28px);
}

.page-about .about-timeline-frame {
  overflow: hidden;
  border: 1px solid var(--rule);
  border-radius: var(--card-radius);
  background: var(--sage);
}

.page-about .about-timeline-frame img {
  display: block;
  width: 100%;
  height: auto;
  aspect-ratio: 8 / 3;
  object-fit: cover;
}

.page-about .about-ruler {
  display: flex;
  align-items: flex-end;
  gap: 6px;
  overflow-x: auto;
  padding: 0 2px 12px;
  margin-bottom: clamp(18px, 2.4vw, 26px);
  border-bottom: 1px solid var(--rule);
  scrollbar-width: thin;
}

.page-about .about-ruler-tick {
  flex: 1 0 auto;
  min-width: 60px;
  position: relative;
  padding-top: 18px;
  font-family: var(--font-mono);
  font-size: 0.82rem;
  letter-spacing: 0.04em;
  text-align: center;
  color: var(--ink-blue);
  text-decoration: none;
  transition: color 0.2s var(--ease);
}

.page-about .about-ruler-tick::before {
  content: "";
  position: absolute;
  top: 0;
  left: 50%;
  width: 1px;
  height: 11px;
  transform: translateX(-50%);
  background: var(--rule);
  transition: background-color 0.2s var(--ease);
}

.page-about .about-ruler-tick:hover,
.page-about .about-ruler-tick:focus-visible {
  color: var(--cyan);
}

.page-about .about-ruler-tick:hover::before,
.page-about .about-ruler-tick:focus-visible::before {
  background: var(--cyan);
}

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

.page-about .about-tl-card {
  scroll-margin-top: 120px;
  padding: 18px 20px 20px;
  background: var(--paper);
  border: 1px solid var(--rule);
  border-radius: 14px;
  transition: border-color 0.28s var(--ease), transform 0.28s var(--ease);
}

.page-about .about-tl-card:hover {
  border-color: var(--cyan);
  transform: translateY(-2px);
}

.page-about .about-tl-year {
  display: inline-block;
  margin-bottom: 0.5em;
  font-family: var(--font-mono);
  font-size: 0.8rem;
  letter-spacing: 0.1em;
  color: var(--cyan);
}

.page-about .about-tl-title {
  margin: 0 0 0.45em;
  font-size: 1.02rem;
  line-height: 1.4;
  color: var(--ink-blue);
}

.page-about .about-tl-text {
  margin: 0;
  font-size: 0.88rem;
  line-height: 1.7;
  color: var(--grey);
}

/* ---------- 团队 ---------- */
.page-about .about-team {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 12px;
  margin-top: clamp(20px, 3vw, 30px);
}

.page-about .about-team-tile {
  padding: 20px 18px 22px;
  border: 1px solid var(--rule);
  border-radius: 14px;
  background: var(--sage);
  transition: border-color 0.28s var(--ease), transform 0.28s var(--ease);
}

.page-about .about-team-tile:nth-child(2) {
  background: var(--mist);
}

.page-about .about-team-tile:nth-child(3) {
  background: var(--orange-soft);
}

.page-about .about-team-tile:hover {
  border-color: var(--cyan);
  transform: translateY(-2px);
}

.page-about .about-team-count {
  display: block;
  margin-bottom: 0.4em;
  font-family: var(--font-mono);
  font-size: clamp(1.8rem, 3.2vw, 2.4rem);
  line-height: 1;
  letter-spacing: -0.03em;
  color: var(--ink-blue);
}

.page-about .about-team-role {
  margin: 0 0 0.4em;
  font-size: 1rem;
  color: var(--ink-blue);
}

.page-about .about-team-duty {
  margin: 0;
  font-size: 0.86rem;
  line-height: 1.7;
  color: var(--grey);
}

.page-about .about-sub {
  margin: clamp(30px, 4vw, 44px) 0 0;
  font-size: clamp(1.05rem, 1.6vw, 1.2rem);
  color: var(--ink-blue);
}

/* ---------- 三级校对 ---------- */
.page-about .about-steps {
  display: grid;
  gap: 10px;
  margin-top: 16px;
}

.page-about .about-step {
  overflow: hidden;
  background: var(--paper);
  border: 1px solid var(--rule);
  border-radius: 12px;
  transition: border-color 0.24s var(--ease);
}

.page-about .about-step[open] {
  border-color: var(--cyan);
}

.page-about .about-step summary {
  display: flex;
  align-items: center;
  gap: 12px;
  padding: 14px 16px;
  cursor: pointer;
  list-style: none;
}

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

.page-about .about-step summary::after {
  content: "+";
  margin-left: auto;
  font-family: var(--font-mono);
  font-size: 1.05rem;
  line-height: 1;
  color: var(--cyan);
}

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

.page-about .about-step-num {
  font-family: var(--font-mono);
  font-size: 0.82rem;
  letter-spacing: 0.06em;
  color: var(--orange);
}

.page-about .about-step-title {
  font-size: 0.98rem;
  font-weight: 600;
  color: var(--ink-blue);
}

.page-about .about-step-sum {
  display: none;
  font-size: 0.82rem;
  color: var(--grey);
}

.page-about .about-step-body {
  padding: 14px 16px 16px;
  border-top: 1px solid var(--rule);
  background: rgba(215, 240, 239, 0.45);
}

.page-about .about-step-body ul {
  margin: 0;
  padding-left: 1.1em;
}

.page-about .about-step-body li {
  margin-bottom: 0.35em;
  font-size: 0.86rem;
  line-height: 1.75;
  color: var(--ink);
}

.page-about .about-step-body li:last-child {
  margin-bottom: 0;
}

.page-about .about-flow-fig {
  margin: clamp(20px, 3vw, 30px) 0 0;
}

.page-about .about-flow-fig img {
  display: block;
  width: 100%;
  height: auto;
  aspect-ratio: 12 / 7;
  object-fit: cover;
  border: 1px solid var(--rule);
  border-radius: var(--card-radius);
  background: var(--sage);
}

.page-about .about-flow-fig .media-caption {
  margin: 10px 2px 0;
}

/* ---------- 测试实验室 ---------- */
.page-about .about-lab-grid {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 10px;
  margin: clamp(18px, 2.6vw, 26px) 0;
}

.page-about .about-lab-item {
  display: flex;
  flex-direction: column;
  gap: 6px;
  padding: 16px 14px;
  background: var(--paper);
  border: 1px solid var(--rule);
  border-radius: 12px;
}

.page-about .about-lab-num {
  font-family: var(--font-mono);
  font-size: clamp(1.4rem, 2.6vw, 1.9rem);
  line-height: 1;
  letter-spacing: -0.02em;
  color: var(--cyan);
}

.page-about .about-lab-label {
  font-size: 0.78rem;
  line-height: 1.45;
  color: var(--grey);
}

/* ---------- 合作与认可 ---------- */
.page-about .about-honor {
  list-style: none;
  margin: clamp(16px, 2.4vw, 24px) 0;
  padding: 0;
  display: grid;
  gap: 10px;
}

.page-about .about-honor li {
  display: flex;
  align-items: baseline;
  gap: 14px;
  padding: 14px 16px;
  font-size: 0.92rem;
  line-height: 1.6;
  color: var(--ink);
  background: var(--paper);
  border-left: 3px solid var(--green);
  border-radius: 0 10px 10px 0;
}

.page-about .about-honor-year {
  flex: 0 0 auto;
  font-family: var(--font-mono);
  font-size: 0.8rem;
  color: var(--green);
}

/* ---------- 服务承诺 ---------- */
.page-about .about-promise {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 1px;
  margin: clamp(18px, 2.6vw, 26px) 0;
  border: 1px solid var(--rule);
  border-radius: 14px;
  overflow: hidden;
  background: var(--rule);
}

.page-about .about-promise-item {
  display: flex;
  flex-direction: column;
  gap: 6px;
  padding: 18px 16px;
  background: var(--paper);
}

.page-about .about-promise-num {
  font-family: var(--font-mono);
  font-size: clamp(1.3rem, 2.4vw, 1.7rem);
  line-height: 1;
  color: var(--ink-blue);
}

.page-about .about-promise-label {
  font-size: 0.78rem;
  line-height: 1.5;
  color: var(--grey);
}

/* ---------- 结尾去向 ---------- */
.page-about .about-cta {
  padding: var(--about-y) 0 0;
}

.page-about .about-cta h2 {
  margin: 0 0 clamp(18px, 2.6vw, 26px);
  color: var(--ink-blue);
}

.page-about .about-links {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 12px;
}

.page-about .about-link-card {
  display: flex;
  flex-direction: column;
  gap: 8px;
  padding: 20px 20px 22px;
  background: var(--paper);
  border: 1px solid var(--rule);
  border-radius: 14px;
  text-decoration: none;
  color: inherit;
  transition: border-color 0.28s var(--ease), transform 0.28s var(--ease), background-color 0.28s var(--ease);
}

.page-about .about-link-card:hover {
  border-color: var(--cyan);
  background: var(--mist);
  transform: translateY(-2px);
}

.page-about .about-link-card:focus-visible {
  outline: 2px solid var(--orange);
  outline-offset: 2px;
}

.page-about .about-link-kicker {
  font-family: var(--font-mono);
  font-size: 0.72rem;
  letter-spacing: 0.14em;
  color: var(--cyan);
}

.page-about .about-link-title {
  font-size: 1rem;
  line-height: 1.5;
  color: var(--ink-blue);
}

.page-about .about-link-card--accent {
  background: var(--orange-soft);
  border-color: var(--orange);
}

.page-about .about-link-card--accent .about-link-kicker {
  color: var(--orange);
}

.page-about .about-link-card--accent:hover {
  background: rgba(242, 140, 40, 0.16);
  border-color: var(--orange);
}

.page-about .about-top {
  margin: clamp(26px, 4vw, 40px) 0 0;
  padding-top: 18px;
  border-top: 1px solid var(--rule);
  font-size: 0.85rem;
}

.page-about .about-top a {
  color: var(--grey);
  text-decoration: none;
  border-bottom: 1px solid var(--rule);
  padding-bottom: 2px;
  transition: color 0.2s var(--ease), border-color 0.2s var(--ease);
}

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

/* ---------- 滚动显现 ---------- */
.page-about .reveal {
  opacity: 0;
  transform: translateY(12px);
  transition: opacity 0.5s var(--ease), transform 0.5s var(--ease);
}

.page-about .reveal[data-visible] {
  opacity: 1;
  transform: none;
}

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

@media (min-width: 700px) {
  .page-about .about-three {
    grid-template-columns: repeat(3, minmax(0, 1fr));
  }

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

  .page-about .about-team-tile {
    display: flex;
    flex-direction: column;
  }

  .page-about .about-step-sum {
    display: inline;
    margin-left: 6px;
  }

  .page-about .about-lab-grid {
    grid-template-columns: repeat(4, minmax(0, 1fr));
  }

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

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

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

/* ---------- 桌面 ---------- */
@media (min-width: 920px) {
  .page-about .about-hero {
    grid-template-columns: minmax(0, 1.06fr) minmax(0, 0.94fr);
    align-items: start;
  }

  .page-about .about-sec {
    grid-template-columns: var(--about-rail) minmax(0, 1fr);
    gap: var(--about-sec-gap);
    align-items: start;
  }

  .page-about .about-sec-rail {
    position: sticky;
    top: clamp(84px, 11vh, 124px);
    align-self: start;
    flex-direction: column;
    align-items: flex-start;
    gap: 16px;
  }

  .page-about .about-sec-anno {
    writing-mode: vertical-rl;
    font-size: 0.68rem;
    letter-spacing: 0.34em;
  }

  .page-about .about-sec-rail::after {
    content: "";
    width: 1px;
    height: clamp(44px, 9vh, 110px);
    background: linear-gradient(var(--rule), transparent);
  }
}

/* ---------- 减少动效 ---------- */
@media (prefers-reduced-motion: reduce) {
  .page-about .reveal {
    opacity: 1;
    transform: none;
    transition: none;
  }

  .page-about .about-three li:hover,
  .page-about .about-team-tile:hover,
  .page-about .about-tl-card:hover,
  .page-about .about-link-card:hover {
    transform: none;
  }
}
<<<END>>>