.page-about {
  font-family: var(--font-sans);
  background: var(--color-bg);
  color: var(--color-text);
  overflow-x: hidden;
}

/* 页面头 */
.page-about .about-hero {
  position: relative;
  max-width: var(--container);
  margin: 0 auto;
  padding: 2.5rem 1.25rem 3.5rem;
  background-image:
    radial-gradient(circle at 82% 16%, rgba(0, 212, 255, 0.09), transparent 40%),
    linear-gradient(to right, rgba(42, 53, 80, 0.14) 1px, transparent 1px),
    linear-gradient(to bottom, rgba(42, 53, 80, 0.14) 1px, transparent 1px);
  background-size: 100% 100%, 2.25rem 2.25rem, 2.25rem 2.25rem;
}

.page-about .about-hero .crumbs {
  margin-bottom: 3rem;
}

.page-about .about-hero__kicker {
  font-family: var(--font-mono);
  font-size: 0.75rem;
  letter-spacing: 0.28em;
  text-transform: uppercase;
  color: var(--color-brand);
  margin: 0 0 1.25rem;
}

.page-about .about-hero h1 {
  font-size: clamp(2.5rem, 7.6vw, 5.25rem);
  font-weight: 200;
  line-height: 1.04;
  letter-spacing: -0.02em;
  margin: 0 0 1.5rem;
  color: var(--color-text);
}

.page-about .about-hero h1 em {
  font-style: normal;
  font-weight: 700;
  color: var(--color-white);
  display: block;
}

.page-about .about-hero__lead {
  max-width: 36em;
  margin: 0;
  font-size: 1.0625rem;
  line-height: 1.8;
  color: var(--color-text-dim);
}

.page-about .about-hero__stats {
  display: flex;
  flex-wrap: wrap;
  gap: 2.25rem;
  margin: 2.5rem 0 0;
  padding: 1.5rem 0 0;
  border-top: 1px solid var(--color-border);
}

.page-about .about-hero__stat {
  display: flex;
  flex-direction: column;
  gap: 0.375rem;
  min-width: 6.5rem;
}

.page-about .about-hero__stat .data-number {
  font-size: 1.875rem;
  font-weight: 700;
  color: var(--color-brand);
}

.page-about .about-hero__stat dd {
  margin: 0;
  font-family: var(--font-mono);
  font-size: 0.6875rem;
  letter-spacing: 0.14em;
  text-transform: uppercase;
  color: var(--color-text-dim);
}

/* 章节索引 */
.page-about .about-section-index {
  font-family: var(--font-mono);
  font-size: 0.8125rem;
  letter-spacing: 0.22em;
  text-transform: uppercase;
  color: var(--color-brand);
  margin: 0 0 1.75rem;
  display: flex;
  align-items: center;
  gap: 1rem;
}

.page-about .about-section-index::after {
  content: "";
  height: 1px;
  flex: 0 0 3.5rem;
  background: var(--color-border);
}

/* 01 品牌档案 */
.page-about .about-archive {
  background: linear-gradient(172deg, transparent 40px, var(--color-card) 40px);
  border-top: 1px solid var(--color-border);
  border-bottom: 1px solid var(--color-border);
}

.page-about .about-archive__inner {
  max-width: var(--container);
  margin: 0 auto;
  padding: 3.5rem 1.25rem 4.5rem;
}

.page-about .about-archive__grid {
  display: grid;
  gap: 2.5rem;
}

.page-about .about-archive__content {
  position: relative;
}

.page-about .about-archive__content::after {
  content: "";
  position: absolute;
  right: 0;
  bottom: 0;
  width: 3rem;
  height: 3rem;
  border-right: 1px solid var(--color-border);
  border-bottom: 1px solid var(--color-border);
  border-radius: 0 0 var(--radius) 0;
  opacity: 0.6;
}

.page-about .about-archive__content h2,
.page-about .about-coverage__head h2,
.page-about .about-path__head h2,
.page-about .about-cert > .about-cert__inner > h2,
.page-about .about-honor__head h2 {
  font-size: clamp(1.75rem, 3.6vw, 2.625rem);
  font-weight: 700;
  line-height: 1.15;
  margin: 0 0 1.25rem;
}

.page-about .about-archive__para {
  color: var(--color-text-dim);
  line-height: 1.75;
  margin: 0 0 1rem;
}

.page-about .about-archive__quote {
  margin: 1.75rem 0 0;
  padding: 1rem 1.25rem;
  border-left: 3px solid var(--color-brand);
  background: rgba(0, 255, 136, 0.05);
  color: var(--color-white);
  font-size: 1.0625rem;
  line-height: 1.6;
}

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

.page-about .about-archive__version {
  display: flex;
  gap: 0.5rem;
  margin-bottom: 0.75rem;
}

.page-about .about-archive__version span {
  font-family: var(--font-mono);
  font-size: 0.625rem;
  letter-spacing: 0.12em;
  padding: 0.25rem 0.625rem;
  border: 1px solid var(--color-border);
  border-radius: var(--radius-pill);
  color: var(--color-text-dim);
}

.page-about .about-archive__version span:last-child {
  color: var(--color-brand);
  border-color: rgba(0, 255, 136, 0.4);
}

.page-about .about-archive__img {
  display: block;
  max-width: 100%;
  height: auto;
  border: 1px solid var(--color-border);
  border-radius: var(--radius);
  background: var(--color-bg);
}

.page-about .about-archive__figure figcaption {
  margin-top: 0.625rem;
  font-family: var(--font-mono);
  font-size: 0.6875rem;
  letter-spacing: 0.08em;
  color: var(--color-text-dim);
}

/* 02 发展历程 */
.page-about .about-path {
  background: var(--color-bg);
}

.page-about .about-path__inner {
  max-width: var(--container);
  margin: 0 auto;
  padding: 4.5rem 1.25rem 4.5rem;
}

.page-about .about-path__head p {
  color: var(--color-text-dim);
  margin: 0;
}

.page-about .about-path__timeline {
  position: relative;
  margin: 2.5rem 0 0;
  padding-left: 2.5rem;
}

.page-about .about-path__line {
  position: absolute;
  top: 0.75rem;
  bottom: 1rem;
  left: 0.625rem;
  width: 2px;
  background: linear-gradient(to bottom, var(--color-brand), var(--color-accent) 70%, transparent);
}

.page-about .about-path__item {
  position: relative;
  margin-bottom: 1.5rem;
  outline: none;
}

.page-about .about-path__node {
  position: absolute;
  top: 1.125rem;
  left: -2.5rem;
  width: 1.25rem;
  height: 1.25rem;
  border-radius: 50%;
  background: var(--color-bg);
  border: 3px solid var(--color-brand);
  box-shadow: 0 0 0 4px rgba(0, 255, 136, 0.12);
}

.page-about .about-path__card {
  background: var(--color-card);
  border: 1px solid var(--color-border);
  border-radius: var(--radius);
  padding: 1.25rem 1.375rem;
  transition: border-color var(--ease), transform var(--ease), box-shadow var(--ease);
}

.page-about .about-path__item:hover .about-path__card,
.page-about .about-path__item:focus-within .about-path__card {
  border-color: var(--color-brand);
  box-shadow: 0 0.5rem 1.75rem rgba(0, 0, 0, 0.35);
  transform: translateX(0.25rem);
}

.page-about .about-path__meta {
  display: flex;
  align-items: center;
  gap: 0.75rem;
  margin-bottom: 0.625rem;
}

.page-about .about-path__year {
  font-family: var(--font-mono);
  font-size: 1.5rem;
  font-weight: 700;
  color: var(--color-brand);
}

.page-about .about-path__flag {
  font-family: var(--font-mono);
  font-size: 0.5625rem;
  letter-spacing: 0.18em;
  text-transform: uppercase;
  color: var(--color-text-dim);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-pill);
  padding: 0.25rem 0.5rem;
}

.page-about .about-path__card h3 {
  font-size: 1.125rem;
  font-weight: 700;
  margin: 0 0 0.5rem;
  color: var(--color-white);
}

.page-about .about-path__summary {
  color: var(--color-text-dim);
  line-height: 1.65;
  margin: 0;
  font-size: 0.9375rem;
}

.page-about .about-path__detail {
  margin: 0;
  padding-top: 0.75rem;
  border-top: 1px solid var(--color-border);
  color: var(--color-text-dim);
  line-height: 1.65;
  font-size: 0.875rem;
  max-height: 0;
  overflow: hidden;
  opacity: 0;
  transition: max-height 0.35s ease, opacity 0.35s ease;
}

.page-about .about-path__item:hover .about-path__detail,
.page-about .about-path__item:focus-within .about-path__detail {
  max-height: 16rem;
  opacity: 1;
}

/* 03 数据服务覆盖 */
.page-about .about-coverage {
  background: linear-gradient(172deg, transparent 40px, var(--color-card) 40px);
  border-top: 1px solid var(--color-border);
  border-bottom: 1px solid var(--color-border);
}

.page-about .about-coverage__inner {
  max-width: var(--container);
  margin: 0 auto;
  padding: 3.5rem 1.25rem 4.5rem;
}

.page-about .about-coverage__head p {
  color: var(--color-text-dim);
  margin: 0;
}

.page-about .about-coverage__grid {
  display: grid;
  gap: 1.75rem;
  margin-top: 2.25rem;
}

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

.page-about .about-coverage__img {
  display: block;
  max-width: 100%;
  height: auto;
  border: 1px solid var(--color-border);
  border-radius: var(--radius);
  background: var(--color-bg);
}

.page-about .about-coverage__figure figcaption {
  margin-top: 0.625rem;
  font-family: var(--font-mono);
  font-size: 0.6875rem;
  letter-spacing: 0.08em;
  color: var(--color-text-dim);
}

.page-about .about-coverage__stats {
  list-style: none;
  margin: 0;
  padding: 0;
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 0.875rem;
}

.page-about .about-coverage__stats li {
  display: flex;
  flex-direction: column;
  gap: 0.25rem;
  background: var(--color-bg);
  border: 1px solid var(--color-border);
  border-radius: var(--radius);
  padding: 1rem 1.125rem;
}

.page-about .about-coverage__stats .data-number {
  font-size: 1.625rem;
  font-weight: 700;
  color: var(--color-brand);
}

.page-about .about-coverage__stats li span:last-child {
  font-size: 0.75rem;
  letter-spacing: 0.06em;
  color: var(--color-text-dim);
}

.page-about .about-coverage__note {
  margin: 2rem 0 0;
  padding: 1rem 0 0 1.125rem;
  border-top: 1px solid var(--color-border);
  border-left: 3px solid var(--color-accent);
  color: var(--color-text-dim);
  line-height: 1.7;
  font-size: 0.9375rem;
}

/* 04 资质与认证 */
.page-about .about-cert {
  background: var(--color-bg);
}

.page-about .about-cert__inner {
  max-width: var(--container);
  margin: 0 auto;
  padding: 4.5rem 1.25rem 5rem;
}

.page-about .about-cert h2 {
  margin-bottom: 2rem;
}

.page-about .about-cert__grid {
  display: grid;
  gap: 2rem;
}

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

.page-about .about-cert__img {
  display: block;
  max-width: 100%;
  height: auto;
  border: 1px solid var(--color-border);
  border-radius: var(--radius);
  background: var(--color-card);
}

.page-about .about-cert__figure figcaption {
  margin-top: 0.625rem;
  font-family: var(--font-mono);
  font-size: 0.6875rem;
  letter-spacing: 0.08em;
  color: var(--color-text-dim);
}

.page-about .about-cert__card {
  background: var(--color-card);
  border: 1px solid var(--color-border);
  border-radius: var(--radius);
  margin-bottom: 1rem;
  overflow: hidden;
}

.page-about .about-cert__card summary {
  cursor: pointer;
  list-style: none;
  padding: 1.125rem 1.375rem;
  font-weight: 700;
  font-size: 1rem;
  line-height: 1.4;
  color: var(--color-white);
  display: flex;
  align-items: center;
  gap: 0.75rem;
  transition: background var(--ease);
}

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

.page-about .about-cert__card summary::before {
  content: "＋";
  font-family: var(--font-mono);
  color: var(--color-brand);
  font-size: 1rem;
  line-height: 1;
}

.page-about .about-cert__card[open] summary::before {
  content: "－";
}

.page-about .about-cert__card summary:hover,
.page-about .about-cert__card[open] summary {
  background: rgba(0, 255, 136, 0.04);
}

.page-about .about-cert__card p {
  margin: 0;
  padding: 0 1.375rem 1.25rem;
  color: var(--color-text-dim);
  line-height: 1.7;
  font-size: 0.9375rem;
}

/* 05 荣誉与认可 */
.page-about .about-honor {
  background: linear-gradient(172deg, transparent 40px, var(--color-card) 40px);
  border-top: 1px solid var(--color-border);
  border-bottom: 1px solid var(--color-border);
}

.page-about .about-honor__inner {
  max-width: var(--container);
  margin: 0 auto;
  padding: 3.5rem 1.25rem 4.5rem;
}

.page-about .about-honor__head p {
  color: var(--color-text-dim);
  margin: 0;
}

.page-about .about-honor__grid {
  display: grid;
  gap: 1rem;
  margin-top: 2.25rem;
}

.page-about .about-honor__card {
  background: var(--color-bg);
  border: 1px solid var(--color-border);
  border-radius: var(--radius);
  padding: 1.5rem 1.375rem;
  transition: border-color var(--ease), transform var(--ease), box-shadow var(--ease);
}

.page-about .about-honor__card:hover {
  border-color: var(--color-brand);
  transform: translateY(-0.25rem);
  box-shadow: 0 0.5rem 1.75rem rgba(0, 0, 0, 0.3);
}

.page-about .about-honor__card .data-number {
  display: block;
  font-size: 2.25rem;
  font-weight: 700;
  color: var(--color-brand);
  letter-spacing: -0.02em;
}

.page-about .about-honor__card h3 {
  font-size: 1.0625rem;
  font-weight: 700;
  color: var(--color-white);
  margin: 0.75rem 0 0.5rem;
}

.page-about .about-honor__card p {
  color: var(--color-text-dim);
  font-size: 0.9375rem;
  line-height: 1.65;
  margin: 0;
}

/* 继续阅读 */
.page-about .about-guide__inner {
  max-width: var(--container);
  margin: 0 auto;
  padding: 4.5rem 1.25rem 5rem;
  text-align: center;
}

.page-about .about-guide__kicker {
  font-family: var(--font-mono);
  font-size: 0.75rem;
  letter-spacing: 0.22em;
  text-transform: uppercase;
  color: var(--color-accent);
  margin: 0 0 0.75rem;
}

.page-about .about-guide h2 {
  font-size: clamp(1.75rem, 3.6vw, 2.375rem);
  font-weight: 700;
  line-height: 1.2;
  margin: 0 0 2rem;
}

.page-about .about-guide__links {
  display: flex;
  flex-wrap: wrap;
  justify-content: center;
  gap: 0.75rem;
  margin: 0;
}

@media (min-width: 48rem) {
  .page-about .about-hero {
    padding-top: 4rem;
    padding-bottom: 6rem;
  }

  .page-about .about-hero__lead {
    font-size: 1.125rem;
  }

  .page-about .about-hero__stats {
    gap: 4rem;
  }

  .page-about .about-archive,
  .page-about .about-coverage,
  .page-about .about-honor {
    background: linear-gradient(168deg, transparent 72px, var(--color-card) 72px);
  }

  .page-about .about-archive__inner,
  .page-about .about-coverage__inner,
  .page-about .about-honor__inner {
    padding-top: 5rem;
    padding-bottom: 6rem;
  }

  .page-about .about-path__inner,
  .page-about .about-cert__inner {
    padding: 6rem 2rem;
  }

  .page-about .about-guide__inner {
    padding: 6rem 2rem;
  }

  .page-about .about-archive__grid {
    grid-template-columns: minmax(0, 7fr) minmax(0, 5fr);
    gap: 3.75rem;
    align-items: start;
  }

  .page-about .about-archive__figure {
    position: sticky;
    top: calc(var(--header-space) + 2rem);
  }

  .page-about .about-coverage__grid {
    grid-template-columns: minmax(0, 5fr) minmax(0, 7fr);
    align-items: center;
    gap: 3rem;
    margin-top: 2.5rem;
  }

  .page-about .about-coverage__stats li {
    padding: 1.25rem;
  }

  .page-about .about-cert__grid {
    grid-template-columns: minmax(0, 5fr) minmax(0, 7fr);
    align-items: start;
    gap: 3.5rem;
    margin-top: 1.5rem;
  }

  .page-about .about-honor__grid {
    grid-template-columns: repeat(3, 1fr);
    gap: 1.5rem;
  }

  .page-about .about-path__timeline {
    max-width: 56rem;
    margin-left: auto;
    margin-right: auto;
    padding-left: 0;
  }

  .page-about .about-path__line {
    left: 50%;
    transform: translateX(-50%);
  }

  .page-about .about-path__item {
    width: calc(50% - 2.25rem);
    margin-left: 0;
    margin-bottom: 2.5rem;
  }

  .page-about .about-path__item:nth-of-type(even) {
    margin-left: calc(50% + 2.25rem);
  }

  .page-about .about-path__node {
    top: 1.5rem;
    left: auto;
    right: calc(-2.25rem - 0.625rem);
  }

  .page-about .about-path__item:nth-of-type(even) .about-path__node {
    right: auto;
    left: calc(-2.25rem - 0.625rem);
  }

  .page-about .about-path__card {
    padding: 1.5rem 1.75rem;
  }

  .page-about .about-path__item:hover .about-path__card,
  .page-about .about-path__item:focus-within .about-path__card {
    transform: translateY(-0.2rem);
  }
}