.page-about {
  --about-rail: rgba(11, 31, 58, .16);
  --about-rail-dark: rgba(220, 230, 242, .2);
  --about-gap: 18px;
  color: var(--graphite);
  background: var(--paper);
  overflow-x: clip;
}

/* ===== 首屏 ===== */
.page-about .about-hero {
  position: relative;
  overflow: hidden;
  padding: 26px 0 54px;
  color: var(--paper);
  background-color: var(--navy);
  background-image: var(--blueprint);
  background-size: 48px 48px;
  border-bottom: 1px solid var(--line-dark);
}

.page-about .about-hero::after {
  content: "";
  position: absolute;
  top: -34%;
  right: -24%;
  width: 74%;
  height: 190%;
  background: linear-gradient(158deg, rgba(200, 16, 46, .52), rgba(200, 16, 46, 0) 64%);
  transform: rotate(16deg);
  pointer-events: none;
}

.page-about .about-hero__inner {
  position: relative;
  z-index: 1;
}

.page-about .about-hero .breadcrumb__list {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 8px;
  margin: 0;
  padding: 0;
  list-style: none;
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: .06em;
}

.page-about .about-hero .breadcrumb__link {
  color: var(--ice);
  text-decoration: none;
  border-bottom: 1px solid transparent;
}

.page-about .about-hero .breadcrumb__link:hover,
.page-about .about-hero .breadcrumb__link:focus-visible {
  border-bottom-color: var(--maple);
}

.page-about .about-hero .breadcrumb__sep,
.page-about .about-hero .breadcrumb__current {
  color: var(--mist);
}

.page-about .about-hero__eyebrow {
  margin: 26px 0 0;
  color: var(--amber);
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: .18em;
  text-transform: uppercase;
}

.page-about .about-hero__title {
  margin: 14px 0 0;
  max-width: 16em;
  font-size: clamp(29px, 7.2vw, 58px);
  line-height: 1.12;
  letter-spacing: -.02em;
  font-weight: 800;
  color: var(--paper);
}

.page-about .about-hero__lede {
  margin: 18px 0 0;
  max-width: 44em;
  font-size: 16px;
  line-height: 1.8;
  color: var(--ice);
}

.page-about .about-hero__index {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 16px;
  margin: 32px 0 0;
  padding: 22px 0 0;
  list-style: none;
  border-top: 1px solid var(--line-dark);
}

.page-about .about-hero__stat {
  display: flex;
  flex-direction: column;
  gap: 6px;
  padding-left: 12px;
  border-left: 1px solid var(--line-dark);
}

.page-about .about-hero__stat-value {
  font-family: var(--font-mono);
  font-size: 24px;
  font-weight: 700;
  letter-spacing: -.01em;
  color: var(--amber);
}

.page-about .about-hero__stat-label {
  font-size: 12px;
  line-height: 1.6;
  color: var(--mist);
}

/* ===== 章节索引 ===== */
.page-about .about-toc {
  padding: 14px 0 12px;
  background: var(--paper);
  border-bottom: 1px solid var(--line);
}

.page-about .about-toc__inner {
  display: flex;
  align-items: center;
  gap: 14px;
}

.page-about .about-toc__label {
  flex: none;
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: .16em;
  color: var(--maple);
  white-space: nowrap;
}

.page-about .about-toc__list {
  display: flex;
  gap: 8px;
  margin: 0;
  padding: 2px 2px 8px;
  list-style: none;
  overflow-x: auto;
  scroll-snap-type: x proximity;
  -webkit-overflow-scrolling: touch;
}

.page-about .about-toc__list::-webkit-scrollbar {
  height: 4px;
}

.page-about .about-toc__list::-webkit-scrollbar-thumb {
  background: var(--line);
  border-radius: 2px;
}

.page-about .about-toc__link {
  display: inline-flex;
  align-items: baseline;
  gap: 8px;
  padding: 8px 12px;
  white-space: nowrap;
  scroll-snap-align: start;
  font-size: 13px;
  color: var(--graphite);
  text-decoration: none;
  background: transparent;
  border: 1px solid var(--line);
  border-radius: var(--radius);
  transition: color .2s var(--ease), border-color .2s var(--ease), background-color .2s var(--ease);
}

.page-about .about-toc__link:hover,
.page-about .about-toc__link:focus-visible {
  border-color: var(--maple);
  color: var(--maple);
}

.page-about .about-toc__link.is-current {
  border-color: var(--maple);
  color: var(--maple);
  background: rgba(200, 16, 46, .07);
}

.page-about .about-toc__num {
  font-family: var(--font-mono);
  font-size: 11px;
  color: var(--mist);
}

.page-about .about-toc__link.is-current .about-toc__num {
  color: var(--maple);
}

/* ===== 通用章节 ===== */
.page-about .about-section {
  padding: 48px 0;
}

.page-about .about-section--ice {
  background: var(--ice);
  border-top: 1px solid rgba(11, 31, 58, .08);
  border-bottom: 1px solid rgba(11, 31, 58, .08);
}

.page-about .about-section--navy {
  color: var(--paper);
  background-color: var(--midnight);
  background-image: var(--blueprint);
  background-size: 44px 44px;
}

.page-about .about-head {
  max-width: 46em;
}

.page-about .about-heading {
  margin: 12px 0 0;
  font-size: clamp(23px, 4.6vw, 38px);
  line-height: 1.22;
  letter-spacing: -.01em;
  font-weight: 800;
  color: var(--navy);
}

.page-about .about-section--navy .about-heading {
  color: var(--paper);
}

.page-about .about-head__lede {
  margin: 14px 0 0;
  font-size: 15px;
  line-height: 1.8;
  color: var(--graphite);
}

.page-about .about-section--navy .about-head__lede {
  color: var(--mist);
}

.page-about .about-prose p {
  margin: 0 0 16px;
  font-size: 15px;
  line-height: 1.85;
  color: var(--graphite);
}

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

/* ===== 定位与直营 ===== */
.page-about .about-position {
  background: var(--paper);
}

.page-about .about-position__grid {
  display: grid;
  gap: 30px;
}

.page-about .about-position__body .prose {
  margin-top: 16px;
}

.page-about .about-aside {
  padding: 20px 18px;
  background: var(--paper);
  border: 1px solid var(--line);
  border-top: 3px solid var(--maple);
  border-radius: var(--radius);
  box-shadow: var(--shadow-soft);
}

.page-about .about-aside__title {
  margin: 0 0 14px;
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: .14em;
  color: var(--maple);
}

.page-about .about-aside__list {
  margin: 0;
  padding: 0;
  list-style: none;
}

.page-about .about-aside__item {
  display: grid;
  gap: 4px;
  padding: 10px 0;
  border-top: 1px dashed var(--line);
}

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

.page-about .about-aside__key {
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: .1em;
  color: var(--mist);
}

.page-about .about-aside__val {
  font-size: 14px;
  font-weight: 600;
  color: var(--navy);
}

.page-about .about-aside__note {
  margin: 14px 0 0;
  padding-top: 12px;
  border-top: 1px solid var(--line);
  font-size: 13px;
  line-height: 1.75;
  color: var(--graphite);
}

/* ===== 版本演进 ===== */
.page-about .about-figure {
  margin: 28px 0 0;
  background: var(--navy);
  border: 1px solid rgba(11, 31, 58, .12);
  border-radius: var(--radius);
  overflow: hidden;
}

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

.page-about .about-figure .media-frame__caption {
  padding: 10px 14px;
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: .08em;
  color: var(--mist);
  background: var(--navy);
}

.page-about .about-timeline {
  margin: 30px 0 0;
  padding: 0;
  list-style: none;
}

.page-about .about-timeline__item {
  position: relative;
  padding: 0 0 28px 26px;
  border-left: 1px solid var(--about-rail);
}

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

.page-about .about-timeline__item::before {
  content: "";
  position: absolute;
  left: -5px;
  top: 6px;
  width: 9px;
  height: 9px;
  border-radius: 50%;
  background: var(--ice);
  border: 2px solid var(--maple);
}

.page-about .about-timeline__item--current::before {
  background: var(--aurora);
  border-color: var(--aurora);
  box-shadow: 0 0 0 4px rgba(46, 230, 166, .22);
}

.page-about .about-timeline__year {
  margin: 0 0 6px;
  font-family: var(--font-mono);
  font-size: 13px;
  letter-spacing: .06em;
  color: var(--maple);
}

.page-about .about-timeline__title {
  margin: 0 0 6px;
  font-size: 17px;
  line-height: 1.4;
  font-weight: 700;
  color: var(--navy);
}

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

/* ===== 认证体系 ===== */
.page-about .about-cert__layout {
  display: grid;
  gap: 26px;
  margin-top: 30px;
}

.page-about .about-cert__figure {
  margin: 0;
  border: 1px solid var(--line-dark);
  border-radius: var(--radius);
  overflow: hidden;
  background: rgba(220, 230, 242, .04);
}

.page-about .about-cert__figure .media-frame__img {
  display: block;
  width: 100%;
  height: auto;
  max-width: 100%;
  object-fit: contain;
}

.page-about .about-cert__figure .media-frame__caption {
  padding: 10px 14px;
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: .08em;
  color: var(--mist);
  border-top: 1px solid var(--line-dark);
}

.page-about .about-cert__list {
  display: grid;
  gap: 12px;
}

.page-about .about-cert__item {
  padding: 14px 16px;
  background: rgba(220, 230, 242, .05);
  border: 1px solid var(--line-dark);
  border-left: 3px solid var(--maple);
  border-radius: var(--radius);
}

.page-about .about-cert__item[open] {
  background: rgba(220, 230, 242, .09);
}

.page-about .about-cert__item summary {
  display: flex;
  align-items: baseline;
  gap: 10px;
  cursor: pointer;
  list-style: none;
  font-size: 16px;
  font-weight: 700;
  color: var(--paper);
}

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

.page-about .about-cert__item summary::after {
  content: "+";
  margin-left: auto;
  font-family: var(--font-mono);
  font-size: 16px;
  color: var(--amber);
}

.page-about .about-cert__item[open] summary::after {
  content: "—";
}

.page-about .about-cert__item p {
  margin: 12px 0 0;
  font-size: 14px;
  line-height: 1.85;
  color: var(--ice);
}

/* ===== 团队与流程 ===== */
.page-about .about-team {
  background: var(--paper);
}

.page-about .about-team__grid {
  display: grid;
  gap: 26px;
  margin-top: 28px;
}

.page-about .about-team__figure {
  margin: 0;
  border: 1px solid var(--line);
  border-radius: var(--radius);
  overflow: hidden;
  background: var(--navy);
}

.page-about .about-team__figure .media-frame__img {
  display: block;
  width: 100%;
  height: auto;
  max-width: 100%;
  object-fit: cover;
}

.page-about .about-team__figure .media-frame__caption {
  padding: 10px 14px;
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: .08em;
  color: var(--mist);
  background: var(--navy);
}

.page-about .about-team__list {
  margin: 0;
  padding: 0;
  list-style: none;
}

.page-about .about-team__item {
  display: grid;
  grid-template-columns: 34px minmax(0, 1fr);
  gap: 12px;
  padding: 16px 0;
  border-top: 1px solid var(--line);
}

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

.page-about .about-team__num {
  font-family: var(--font-mono);
  font-size: 13px;
  font-weight: 700;
  color: var(--maple);
  padding-top: 3px;
}

.page-about .about-team__name {
  margin: 0 0 6px;
  font-size: 17px;
  font-weight: 700;
  color: var(--navy);
}

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

.page-about .about-checks {
  margin-top: 30px;
  padding: 20px 18px;
  background: var(--ice);
  border-radius: var(--radius);
  border: 1px solid rgba(11, 31, 58, .1);
}

.page-about .about-checks__title {
  margin: 0 0 16px;
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: .12em;
  color: var(--maple);
}

.page-about .about-checks__list {
  display: grid;
  gap: 14px;
  margin: 0;
  padding: 0;
  list-style: none;
}

.page-about .about-checks__item {
  display: grid;
  gap: 3px;
  padding-left: 12px;
  border-left: 2px solid var(--navy);
}

.page-about .about-checks__index {
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: .08em;
  color: var(--mist);
}

.page-about .about-checks__name {
  font-size: 15px;
  font-weight: 700;
  color: var(--navy);
}

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

/* ===== 服务规模 ===== */
.page-about .about-scale {
  color: var(--paper);
  background-color: var(--midnight);
  background-image: var(--blueprint);
  background-size: 46px 46px;
  border-top: 3px solid var(--maple);
}

.page-about .about-eyebrow--amber {
  margin: 0;
  color: var(--amber);
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: .18em;
}

.page-about .about-scale__grid {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 14px;
  margin: 26px 0 0;
  padding: 0;
  list-style: none;
}

.page-about .about-scale__item {
  display: flex;
  flex-direction: column;
  gap: 6px;
  padding: 16px 14px;
  border: 1px solid var(--about-rail-dark);
  border-radius: var(--radius);
  background: rgba(220, 230, 242, .04);
}

.page-about .about-scale__value {
  font-family: var(--font-mono);
  font-size: 26px;
  font-weight: 700;
  color: var(--amber);
  letter-spacing: -.01em;
}

.page-about .about-scale__label {
  font-size: 12px;
  line-height: 1.6;
  color: var(--mist);
}

.page-about .about-scale__note {
  margin: 20px 0 0;
  max-width: 46em;
  font-size: 14px;
  line-height: 1.85;
  color: var(--ice);
}

.page-about .about-cta {
  margin-top: 30px;
  padding-top: 22px;
  border-top: 1px solid var(--about-rail-dark);
}

.page-about .about-cta__title {
  margin: 0 0 14px;
  font-size: 17px;
  font-weight: 700;
  color: var(--paper);
}

.page-about .about-cta__actions {
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
}

.page-about .about-cta__actions .btn {
  text-decoration: none;
}

.page-about .about-cta__actions .btn--primary {
  background: var(--maple);
  border-color: var(--maple);
  color: var(--paper);
}

.page-about .about-cta__actions .btn--primary:hover,
.page-about .about-cta__actions .btn--primary:focus-visible {
  background: var(--maple-deep);
  border-color: var(--maple-deep);
}

.page-about .about-cta__actions .btn--ghost {
  background: transparent;
  border-color: var(--about-rail-dark);
  color: var(--ice);
}

.page-about .about-cta__actions .btn--ghost:hover,
.page-about .about-cta__actions .btn--ghost:focus-visible {
  border-color: var(--aurora);
  color: var(--aurora);
}

/* ===== 断点 ===== */
@media (min-width: 720px) {
  .page-about .about-hero {
    padding: 32px 0 68px;
  }

  .page-about .about-hero__index {
    grid-template-columns: repeat(4, minmax(0, 1fr));
    gap: 18px;
  }

  .page-about .about-hero__stat:nth-child(2) {
    transform: translateY(10px);
  }

  .page-about .about-hero__stat:nth-child(4) {
    transform: translateY(-6px);
  }

  .page-about .about-section {
    padding: 60px 0;
  }

  .page-about .about-checks__list {
    grid-template-columns: repeat(3, minmax(0, 1fr));
    gap: 18px;
  }

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

@media (min-width: 900px) {
  .page-about .about-hero__title {
    max-width: 13em;
  }

  .page-about .about-hero__lede {
    font-size: 17px;
  }

  .page-about .about-position__grid {
    grid-template-columns: minmax(0, 1.6fr) minmax(0, .85fr);
    gap: 44px;
    align-items: start;
  }

  .page-about .about-aside {
    position: relative;
    top: 6px;
  }

  .page-about .about-timeline {
    margin-top: 34px;
  }

  .page-about .about-timeline__item {
    display: grid;
    grid-template-columns: 130px minmax(0, 1fr);
    gap: 26px;
    padding-left: 30px;
  }

  .page-about .about-timeline__year {
    margin: 2px 0 0;
    font-size: 14px;
    text-align: right;
  }

  .page-about .about-cert__layout {
    grid-template-columns: minmax(0, .8fr) minmax(0, 1.2fr);
    gap: 34px;
    align-items: start;
  }

  .page-about .about-team__grid {
    grid-template-columns: minmax(0, 1.05fr) minmax(0, 1fr);
    gap: 36px;
    align-items: start;
  }

  .page-about .about-checks {
    padding: 24px 22px;
  }
}

@media (min-width: 1100px) {
  .page-about .about-section {
    padding: 72px 0;
  }

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

  .page-about .about-cert__item {
    padding: 18px 20px;
  }
}

@media (prefers-reduced-motion: reduce) {
  .page-about .about-hero__stat:nth-child(2),
  .page-about .about-hero__stat:nth-child(4) {
    transform: none;
  }

  .page-about .about-toc__link {
    transition: none;
  }
}