.page-about {
  --about-rail-w: 104px;
  background: var(--fx-cream);
  color: var(--fx-ink);
}

/* ---------- 首屏 ---------- */
.page-about .about-hero {
  position: relative;
  overflow: hidden;
  border-bottom: 3px solid var(--fx-ink);
  background:
    linear-gradient(180deg, rgba(255, 77, 26, 0.10) 0%, rgba(245, 242, 234, 0) 58%),
    var(--fx-cream);
}

.page-about .about-hero::before {
  content: "";
  position: absolute;
  top: 0;
  left: 0;
  width: 6px;
  height: 100%;
  background: var(--fx-orange);
}

.page-about .about-hero__inner {
  max-width: var(--fx-wrap-max);
  margin: 0 auto;
  padding: clamp(22px, 4vw, 42px) var(--fx-gutter) clamp(26px, 4vw, 44px);
}

.page-about .about-hero__eyebrow {
  margin: 22px 0 12px;
  font-family: var(--fx-font-mono);
  font-size: 12px;
  letter-spacing: 0.18em;
  color: var(--fx-darkorange);
}

.page-about .about-hero__title {
  margin: 0;
  font-family: var(--fx-font-narrow);
  font-size: clamp(38px, 7.6vw, 84px);
  font-weight: 900;
  line-height: 1.02;
  letter-spacing: -0.02em;
  color: var(--fx-ink);
}

.page-about .about-hero__lede {
  margin: 20px 0 0;
  max-width: 62ch;
  font-size: 16px;
  line-height: 1.85;
  color: var(--fx-charcoal);
}

.page-about .about-hero__tags {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
  margin: 24px 0 0;
  padding: 0;
  list-style: none;
}

.page-about .about-hero__media {
  max-width: var(--fx-wrap-max);
  margin: 0 auto;
  padding: 0 var(--fx-gutter) clamp(30px, 5vw, 56px);
}

.page-about .about-hero__media img {
  display: block;
  width: 100%;
  height: auto;
  aspect-ratio: 3 / 2;
  object-fit: cover;
  border: 3px solid var(--fx-ink);
  box-shadow: 6px 6px 0 var(--fx-orange);
}

.page-about .about-hero__media .fx-media__cap {
  margin-top: 14px;
  font-family: var(--fx-font-mono);
  font-size: 12px;
  line-height: 1.6;
  color: var(--fx-fog);
}

/* ---------- 长卷章节骨架 ---------- */
.page-about .about-chapter {
  border-top: 3px solid var(--fx-ink);
}

.page-about .about-chapter--dark {
  background: var(--fx-ink);
  color: var(--fx-cream);
  border-top-color: var(--fx-orange);
}

.page-about .about-chapter--paper {
  background: var(--fx-beige);
}

.page-about .about-chapter__inner {
  max-width: var(--fx-wrap-max);
  margin: 0 auto;
  padding: clamp(36px, 6vw, 80px) var(--fx-gutter);
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 14px;
}

.page-about .about-chapter__rail {
  display: flex;
  align-items: flex-start;
}

.page-about .about-chapter__num {
  font-family: var(--fx-font-mono);
  font-size: clamp(38px, 9vw, 88px);
  font-weight: 700;
  line-height: 0.8;
  letter-spacing: -0.04em;
  color: var(--fx-orange);
}

.page-about .about-chapter--dark .about-chapter__num {
  color: var(--fx-yellow);
}

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

.page-about .about-heading {
  margin: 8px 0 0;
  font-family: var(--fx-font-narrow);
  font-size: clamp(25px, 4.2vw, 40px);
  font-weight: 800;
  line-height: 1.14;
  letter-spacing: -0.01em;
}

.page-about .about-prose {
  display: grid;
  gap: 16px;
  max-width: 66ch;
  margin-top: 18px;
}

.page-about .about-prose p {
  margin: 0;
  font-size: 16px;
  line-height: 1.85;
  color: var(--fx-charcoal);
}

.page-about .about-chapter--dark .about-prose p {
  color: rgba(245, 242, 234, 0.84);
}

/* ---------- 01 支柱条目 ---------- */
.page-about .about-pillars {
  margin: 26px 0 0;
  padding: 0;
  list-style: none;
  border-top: 2px solid var(--fx-ink);
}

.page-about .about-pillars li {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 4px;
  padding: 14px 0;
  border-bottom: 1px solid var(--fx-beige);
}

.page-about .about-pillars__k {
  font-family: var(--fx-font-mono);
  font-size: 11px;
  letter-spacing: 0.16em;
  color: var(--fx-darkorange);
}

.page-about .about-pillars__v {
  font-size: 15px;
  line-height: 1.7;
  color: var(--fx-ink);
}

/* ---------- 02 版本时间轴 ---------- */
.page-about .about-timeline {
  position: relative;
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 14px;
  margin-top: 30px;
}

.page-about .about-tl__node {
  position: relative;
  padding: 16px 16px 18px;
  background: var(--fx-charcoal);
  border: 2px solid rgba(245, 242, 234, 0.26);
  color: var(--fx-cream);
  transition: transform 0.2s ease, box-shadow 0.2s ease, border-color 0.2s ease;
}

.page-about .about-tl__node--current {
  background: var(--fx-orange);
  color: var(--fx-ink);
  border-color: var(--fx-yellow);
}

.page-about .about-tl__node:hover,
.page-about .about-tl__node:focus {
  transform: translateY(-4px);
  border-color: var(--fx-yellow);
  box-shadow: 6px 6px 0 rgba(255, 197, 61, 0.42);
}

.page-about .about-tl__node:focus-visible {
  outline: 3px solid var(--fx-blue);
  outline-offset: 3px;
}

.page-about .about-tl__step {
  display: inline-block;
  font-family: var(--fx-font-mono);
  font-size: 11px;
  letter-spacing: 0.16em;
  color: var(--fx-yellow);
}

.page-about .about-tl__node--current .about-tl__step {
  color: var(--fx-ink);
}

.page-about .about-tl__title {
  margin: 10px 0 8px;
  font-size: 17px;
  font-weight: 700;
  line-height: 1.35;
}

.page-about .about-tl__desc {
  margin: 0;
  font-size: 14px;
  line-height: 1.72;
  color: rgba(245, 242, 234, 0.82);
}

.page-about .about-tl__node--current .about-tl__desc {
  color: rgba(20, 20, 20, 0.84);
}

.page-about .about-figure {
  margin: 30px 0 0;
}

.page-about .about-figure img {
  display: block;
  width: 100%;
  height: auto;
  aspect-ratio: 16 / 7;
  object-fit: cover;
  border: 3px solid var(--fx-orange);
  background: var(--fx-charcoal);
}

.page-about .about-figure--team img {
  aspect-ratio: 3 / 2;
  border-color: var(--fx-ink);
}

.page-about .about-figure .fx-media__cap {
  margin-top: 12px;
  font-family: var(--fx-font-mono);
  font-size: 12px;
  line-height: 1.6;
  color: var(--fx-fog);
}

.page-about .about-chapter--dark .about-figure .fx-media__cap {
  color: rgba(245, 242, 234, 0.6);
}

.page-about .about-followup {
  margin: 26px 0 0;
  padding-left: 14px;
  border-left: 5px solid var(--fx-orange);
  font-size: 15px;
  line-height: 1.8;
  color: rgba(245, 242, 234, 0.86);
}

.page-about .about-followup--plain {
  padding-left: 14px;
  border-left-color: var(--fx-blue);
  color: var(--fx-charcoal);
}

.page-about .about-inline-link {
  color: var(--fx-yellow);
  text-decoration: underline;
  text-decoration-thickness: 2px;
  text-underline-offset: 3px;
}

.page-about .about-inline-link:hover,
.page-about .about-inline-link:focus-visible {
  color: var(--fx-blue);
}

/* ---------- 03 团队四象限 ---------- */
.page-about .about-team {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 12px;
  margin-top: 26px;
}

.page-about .about-team__item {
  padding: 16px 16px 18px;
  background: transparent;
  border: 2px solid var(--fx-ink);
  border-left: 6px solid var(--fx-orange);
}

.page-about .about-team__no {
  font-family: var(--fx-font-mono);
  font-size: 11px;
  letter-spacing: 0.16em;
  color: var(--fx-fog);
}

.page-about .about-team__name {
  margin: 8px 0 6px;
  font-size: 17px;
  font-weight: 700;
}

.page-about .about-team__item p {
  margin: 0;
  font-size: 14.5px;
  line-height: 1.75;
  color: var(--fx-charcoal);
}

/* ---------- 04 服务版图 ---------- */
.page-about .about-metrics {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 1px;
  margin: 26px 0 0;
  padding: 0;
  list-style: none;
  background: var(--fx-ink);
  border: 2px solid var(--fx-ink);
}

.page-about .about-metrics li {
  display: flex;
  flex-direction: column;
  gap: 6px;
  padding: 16px 14px;
  background: var(--fx-cream);
}

.page-about .about-metrics__n {
  font-family: var(--fx-font-mono);
  font-size: clamp(26px, 5vw, 38px);
  font-weight: 700;
  line-height: 1;
  color: var(--fx-darkorange);
}

.page-about .about-metrics__l {
  font-size: 13px;
  line-height: 1.5;
  color: var(--fx-charcoal);
}

.page-about .about-legend {
  margin-top: 30px;
  border-top: 3px solid var(--fx-ink);
}

.page-about .about-legend__item {
  border-bottom: 1px solid rgba(20, 20, 20, 0.18);
}

.page-about .about-legend__sum {
  display: grid;
  grid-template-columns: 34px minmax(0, 1fr);
  gap: 12px;
  align-items: center;
  padding: 15px 0;
  cursor: pointer;
  list-style: none;
  font-size: 16px;
  font-weight: 600;
  color: var(--fx-ink);
}

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

.page-about .about-legend__sum:focus-visible {
  outline: 3px solid var(--fx-blue);
  outline-offset: 2px;
}

.page-about .about-legend__coord {
  display: grid;
  place-items: center;
  width: 30px;
  height: 30px;
  background: var(--fx-ink);
  color: var(--fx-yellow);
  font-family: var(--fx-font-mono);
  font-size: 13px;
  font-weight: 700;
}

.page-about .about-legend__item[open] .about-legend__coord {
  background: var(--fx-orange);
  color: var(--fx-ink);
}

.page-about .about-legend__body {
  margin: 0 0 18px;
  font-size: 15px;
  line-height: 1.8;
  color: var(--fx-charcoal);
}

/* ---------- 05 质量档案 ---------- */
.page-about .about-checks {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 18px;
  margin: 26px 0 0;
  padding: 0;
  list-style: none;
}

.page-about .about-checks li {
  padding-top: 12px;
  border-top: 3px solid var(--fx-orange);
}

.page-about .about-checks__no {
  font-family: var(--fx-font-mono);
  font-size: 11px;
  letter-spacing: 0.16em;
  color: var(--fx-darkorange);
}

.page-about .about-checks__name {
  margin: 8px 0 6px;
  font-size: 17px;
  font-weight: 700;
}

.page-about .about-checks li p {
  margin: 0;
  font-size: 14.5px;
  line-height: 1.75;
  color: var(--fx-charcoal);
}

.page-about .about-quality {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 1px;
  margin-top: 28px;
  background: var(--fx-ink);
  border: 2px solid var(--fx-ink);
}

.page-about .about-quality > div {
  display: flex;
  flex-direction: column;
  gap: 6px;
  padding: 16px 14px;
  background: var(--fx-cream);
}

.page-about .about-quality__n {
  font-family: var(--fx-font-mono);
  font-size: clamp(22px, 4vw, 30px);
  font-weight: 700;
  line-height: 1;
  color: var(--fx-darkorange);
}

.page-about .about-quality__l {
  font-size: 13px;
  line-height: 1.5;
  color: var(--fx-charcoal);
}

/* ---------- 06 基地与联系 ---------- */
.page-about .about-contact {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 18px;
  margin-top: 28px;
}

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

.page-about .about-contact__row {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 4px;
  padding: 12px 0;
  border-bottom: 1px solid rgba(245, 242, 234, 0.18);
}

.page-about .about-contact__k {
  font-family: var(--fx-font-mono);
  font-size: 11px;
  letter-spacing: 0.16em;
  color: var(--fx-yellow);
}

.page-about .about-contact__v {
  font-size: 15px;
  line-height: 1.7;
  color: var(--fx-cream);
  overflow-wrap: anywhere;
}

.page-about .about-contact__v a {
  color: var(--fx-cream);
  text-decoration: underline;
  text-decoration-color: var(--fx-orange);
  text-decoration-thickness: 2px;
  text-underline-offset: 3px;
}

.page-about .about-contact__v a:hover,
.page-about .about-contact__v a:focus-visible {
  color: var(--fx-blue);
}

.page-about .about-actions {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
  margin-top: 28px;
}

/* ---------- 断点 ---------- */
@media (min-width: 600px) {
  .page-about .about-pillars li {
    grid-template-columns: 120px minmax(0, 1fr);
    gap: 16px;
    align-items: baseline;
  }

  .page-about .about-contact__row {
    grid-template-columns: 88px minmax(0, 1fr);
    gap: 14px;
    align-items: baseline;
  }

  .page-about .about-legend__body {
    padding-left: 46px;
  }
}

@media (min-width: 720px) {
  .page-about .about-team {
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }

  .page-about .about-checks {
    grid-template-columns: repeat(3, minmax(0, 1fr));
    gap: 20px;
  }
}

@media (min-width: 860px) {
  .page-about .about-chapter__inner {
    grid-template-columns: var(--about-rail-w) minmax(0, 1fr);
    gap: 0 clamp(24px, 5vw, 64px);
    align-items: start;
  }

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

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

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

  .page-about .about-contact {
    grid-template-columns: repeat(2, minmax(0, 1fr));
    gap: 32px;
  }
}

@media (min-width: 900px) {
  .page-about .about-timeline {
    grid-template-columns: repeat(4, minmax(0, 1fr));
    gap: 16px;
    padding-top: 36px;
  }

  .page-about .about-timeline::before {
    content: "";
    position: absolute;
    top: 12px;
    left: 0;
    right: 0;
    height: 4px;
    background: var(--fx-orange);
  }

  .page-about .about-tl__node {
    padding-top: 18px;
  }

  .page-about .about-tl__node::before {
    content: "";
    position: absolute;
    top: -29px;
    left: 16px;
    width: 14px;
    height: 14px;
    background: var(--fx-cream);
    border: 3px solid var(--fx-orange);
    border-radius: 50%;
  }

  .page-about .about-tl__node--current::before {
    background: var(--fx-yellow);
    border-color: var(--fx-yellow);
  }
}

@media (prefers-reduced-motion: reduce) {
  .page-about .about-tl__node {
    transition: none;
  }

  .page-about .about-tl__node:hover,
  .page-about .about-tl__node:focus {
    transform: none;
  }
}
<<<END>>>