.page-about {
  --about-rail-w: 200px;
  --about-ink-text: #3A4D5E;
  background: var(--ink);
  color: var(--paper);
  overflow-x: hidden;
}

/* ---------- 面包屑 ---------- */
.page-about .breadcrumbs {
  padding-top: clamp(18px, 3vw, 28px);
  font-family: var(--font-mono);
  font-size: var(--fs-12);
  letter-spacing: 0.04em;
  color: var(--fog);
}

.page-about .breadcrumbs ol {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 8px;
  margin: 0;
  padding: 0;
  list-style: none;
}

.page-about .breadcrumbs a {
  color: var(--fog);
  text-decoration: none;
  transition: color 0.2s var(--ease);
}

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

.page-about .breadcrumbs li + li::before {
  content: "/";
  margin-right: 8px;
  color: var(--line);
}

.page-about .breadcrumbs [aria-current="page"] {
  color: var(--paper);
}

/* ---------- 首屏 ---------- */
.page-about .about-hero {
  position: relative;
  isolation: isolate;
  overflow: hidden;
  padding: clamp(28px, 4vw, 44px) 0 clamp(44px, 6vw, 80px);
  border-bottom: 1px solid var(--line);
}

.page-about .about-hero::before {
  content: "";
  position: absolute;
  inset: -30% -12% auto -12%;
  height: 150%;
  z-index: -1;
  pointer-events: none;
  background:
    radial-gradient(58% 66% at 84% 6%, rgba(63, 224, 208, 0.16), transparent 70%),
    radial-gradient(48% 60% at 4% 98%, rgba(255, 178, 92, 0.13), transparent 70%);
}

.page-about .about-hero__title {
  margin: 16px 0 0;
  max-width: 15em;
  font-family: var(--font-head);
  font-weight: 900;
  font-size: clamp(30px, 6.2vw, 56px);
  line-height: 1.14;
  letter-spacing: -0.02em;
  color: var(--paper);
}

.page-about .about-hero__lead {
  margin: 22px 0 0;
  max-width: 60ch;
  font-size: var(--fs-body);
  line-height: 1.85;
  color: rgba(246, 241, 230, 0.86);
}

.page-about .about-hero__stats {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(140px, 1fr));
  gap: 1px;
  margin: clamp(28px, 4vw, 44px) 0 0;
  padding: 0;
  list-style: none;
  background: var(--line);
  border: 1px solid var(--line);
  border-radius: var(--radius-md);
  overflow: hidden;
}

.page-about .about-hero__stats > li {
  padding: 20px 22px;
  background: rgba(18, 41, 61, 0.78);
}

.page-about .about-hero__num {
  display: block;
  font-size: clamp(28px, 4.4vw, 44px);
  font-weight: 700;
  line-height: 1;
  letter-spacing: -0.01em;
  color: var(--cyan);
}

.page-about .about-hero__stats > li:nth-child(2n) .about-hero__num {
  color: var(--amber);
}

.page-about .about-hero__label {
  display: block;
  margin-top: 10px;
  font-family: var(--font-mono);
  font-size: var(--fs-12);
  letter-spacing: 0.06em;
  color: var(--fog);
}

/* ---------- 主体骨架 ---------- */
.page-about .about-shell {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 24px;
  padding-top: clamp(34px, 5vw, 60px);
  padding-bottom: clamp(52px, 8vw, 104px);
}

/* ---------- 章节索引 ---------- */
.page-about .about-rail__inner {
  display: flex;
  align-items: center;
  gap: 10px;
  overflow-x: auto;
  padding-bottom: 6px;
  scrollbar-width: thin;
}

.page-about .toc__title {
  display: none;
  margin: 0;
  font-family: var(--font-mono);
  font-size: var(--fs-12);
  letter-spacing: 0.14em;
  text-transform: uppercase;
  color: var(--fog);
}

.page-about .toc {
  display: flex;
  gap: 8px;
}

.page-about .toc__link {
  flex: 0 0 auto;
  display: inline-flex;
  align-items: center;
  padding: 8px 14px;
  border: 1px solid var(--line);
  border-radius: var(--pill);
  font-family: var(--font-mono);
  font-size: var(--fs-12);
  letter-spacing: 0.04em;
  white-space: nowrap;
  color: var(--fog);
  text-decoration: none;
  transition: color 0.2s var(--ease), border-color 0.2s var(--ease), background-color 0.2s var(--ease);
}

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

.page-about .toc__link[aria-current="true"] {
  color: var(--ink);
  background: var(--cyan);
  border-color: var(--cyan);
}

/* ---------- 章节通用 ---------- */
.page-about .about-flow > .about-chapter {
  padding: clamp(34px, 5.5vw, 62px) 0;
  border-top: 1px solid var(--line);
}

.page-about .about-flow > .about-chapter:first-child {
  padding-top: 0;
  border-top: 0;
}

.page-about .about-chapter__title {
  margin: 12px 0 0;
  max-width: 22em;
  font-family: var(--font-head);
  font-weight: 800;
  font-size: clamp(24px, 3.6vw, 34px);
  line-height: 1.26;
  letter-spacing: -0.01em;
  color: var(--paper);
}

.page-about .about-chapter__lead {
  margin: 18px 0 0;
  max-width: 58ch;
  font-size: var(--fs-body);
  line-height: 1.85;
  color: var(--fog);
}

/* ---------- 纸面面板 ---------- */
.page-about .about-paper {
  margin: 26px 0 0;
  padding: clamp(22px, 3.6vw, 40px);
  border: 1px solid var(--paper-2);
  border-radius: var(--radius-lg);
  background: var(--paper);
  color: var(--ink);
}

.page-about .about-paper p {
  margin: 0 0 1.15em;
  font-size: var(--fs-body);
  line-height: 1.85;
  color: var(--ink);
}

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

/* ---------- 时间线 ---------- */
.page-about .about-timeline-figure {
  margin: 28px 0 0;
}

.page-about .media-frame {
  display: block;
  margin: 0;
}

.page-about .media-frame img {
  display: block;
  width: 100%;
  max-width: 100%;
  height: auto;
  border-radius: var(--radius-md);
  object-fit: cover;
  border: 1px solid var(--line);
  background: var(--card);
}

.page-about .media-frame__caption {
  margin-top: 12px;
  font-family: var(--font-mono);
  font-size: var(--fs-12);
  letter-spacing: 0.04em;
  color: var(--fog);
}

.page-about .about-timeline {
  display: block;
  margin: clamp(30px, 4vw, 44px) 0 0 6px;
  padding: 0 0 0 26px;
  list-style: none;
  border-left: 1px solid var(--line);
}

.page-about .about-timeline > li {
  position: relative;
  padding-bottom: 30px;
}

.page-about .about-timeline > li:last-child {
  padding-bottom: 0;
}

.page-about .about-timeline > li::before {
  content: "";
  position: absolute;
  left: -31px;
  top: 8px;
  width: 9px;
  height: 9px;
  border-radius: 50%;
  background: var(--ink);
  border: 2px solid var(--cyan);
}

.page-about .about-timeline > li:last-child::before {
  border-color: var(--amber);
  background: var(--amber);
}

.page-about .timeline__time {
  display: inline-block;
  padding: 3px 12px;
  border: 1px solid rgba(255, 178, 92, 0.32);
  border-radius: var(--pill);
  background: rgba(255, 178, 92, 0.1);
  font-family: var(--font-mono);
  font-size: var(--fs-14);
  letter-spacing: 0.08em;
  color: var(--amber);
}

.page-about .about-timeline__body h3 {
  margin: 10px 0 6px;
  font-family: var(--font-head);
  font-size: var(--fs-20);
  font-weight: 700;
  line-height: 1.4;
  color: var(--paper);
}

.page-about .about-timeline__body p {
  margin: 0;
  max-width: 58ch;
  font-size: var(--fs-16);
  line-height: 1.8;
  color: var(--fog);
}

.page-about .about-timeline__note {
  margin-top: 10px;
  max-height: 0;
  opacity: 0;
  overflow: hidden;
  font-family: var(--font-mono);
  font-size: var(--fs-12);
  letter-spacing: 0.03em;
  color: var(--cyan);
  transition: max-height 0.25s var(--ease), opacity 0.25s var(--ease), margin-top 0.25s var(--ease);
}

.page-about .about-timeline > li:hover .about-timeline__note,
.page-about .about-timeline > li:focus-within .about-timeline__note {
  max-height: 6em;
  opacity: 1;
  margin-top: 10px;
}

@media (hover: none) {
  .page-about .about-timeline__note {
    max-height: 6em;
    opacity: 1;
    margin-top: 10px;
  }
}

/* ---------- 资料体系 ---------- */
.page-about .about-split {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 28px;
  margin-top: 26px;
}

.page-about .about-split__main p {
  margin: 0 0 1.1em;
  max-width: 60ch;
  font-size: var(--fs-body);
  line-height: 1.85;
  color: rgba(246, 241, 230, 0.86);
}

.page-about .about-facts {
  display: grid;
  gap: 1px;
  margin: 26px 0 0;
  padding: 0;
  list-style: none;
  background: var(--line);
  border: 1px solid var(--line);
  border-radius: var(--radius-md);
  overflow: hidden;
}

.page-about .about-facts > li {
  display: grid;
  grid-template-columns: minmax(4.5ch, auto) minmax(0, 1fr);
  align-items: baseline;
  gap: 16px;
  padding: 16px 18px;
  background: var(--card);
}

.page-about .about-facts__num {
  font-family: var(--font-mono);
  font-size: var(--fs-20);
  font-weight: 700;
  letter-spacing: -0.01em;
  color: var(--cyan);
}

.page-about .about-facts > li:nth-child(2n) .about-facts__num {
  color: var(--amber);
}

.page-about .about-facts > li > span:last-child {
  font-size: var(--fs-16);
  line-height: 1.7;
  color: rgba(246, 241, 230, 0.82);
}

.page-about .about-split__media {
  align-self: start;
}

/* ---------- 团队 ---------- */
.page-about .about-team {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 18px;
  margin-top: 26px;
}

.page-about .about-team__item {
  display: grid;
  grid-template-columns: auto minmax(0, 1fr);
  gap: 18px;
  padding: 22px 24px;
  border: 1px solid var(--line);
  border-radius: var(--radius-md);
  background: var(--card);
  transition: transform 0.2s var(--ease), border-color 0.2s var(--ease);
}

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

.page-about .about-team__num {
  font-family: var(--font-mono);
  font-size: clamp(28px, 3.6vw, 42px);
  font-weight: 700;
  line-height: 1;
  color: var(--amber);
}

.page-about .about-team__item h3 {
  margin: 0 0 8px;
  font-family: var(--font-head);
  font-size: var(--fs-20);
  font-weight: 700;
  line-height: 1.4;
  color: var(--paper);
}

.page-about .about-team__item p {
  margin: 0;
  font-size: var(--fs-16);
  line-height: 1.8;
  color: var(--fog);
}

.page-about .about-team__aside {
  margin: 20px 0 0;
  padding-left: 16px;
  border-left: 1px solid var(--line);
  font-family: var(--font-mono);
  font-size: var(--fs-14);
  line-height: 1.9;
  letter-spacing: 0.02em;
  color: var(--fog);
}

/* ---------- 服务准则 ---------- */
.page-about .about-principles {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 26px;
  margin-top: 26px;
  padding: clamp(22px, 3.6vw, 42px);
  border-radius: var(--radius-lg);
  background: var(--paper);
  color: var(--ink);
}

.page-about .about-principle__idx {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 34px;
  height: 34px;
  border-radius: 50%;
  background: var(--ink);
  color: var(--amber);
  font-family: var(--font-mono);
  font-size: var(--fs-14);
  font-weight: 700;
  letter-spacing: 0.02em;
}

.page-about .about-principle h3 {
  margin: 14px 0 8px;
  font-family: var(--font-head);
  font-size: var(--fs-20);
  font-weight: 700;
  line-height: 1.4;
  color: var(--ink);
}

.page-about .about-principle p {
  margin: 0;
  font-size: var(--fs-16);
  line-height: 1.85;
  color: var(--about-ink-text);
}

.page-about .about-principles__media {
  margin: 22px 0 0;
}

/* ---------- 下一步 ---------- */
.page-about .about-next {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 16px;
  margin-top: 28px;
}

.page-about .about-next__card {
  display: flex;
  flex-direction: column;
  gap: 10px;
  padding: 24px;
  border: 1px solid var(--line);
  border-radius: var(--radius-md);
  background: linear-gradient(160deg, rgba(18, 41, 61, 0.92), rgba(10, 26, 43, 0.92));
  color: var(--paper);
  text-decoration: none;
  transition: transform 0.2s var(--ease), border-color 0.2s var(--ease);
}

.page-about .about-next__card:hover,
.page-about .about-next__card:focus-visible {
  transform: translateY(-2px);
  border-color: var(--amber);
}

.page-about .about-next__idx {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 30px;
  height: 30px;
  border-radius: 50%;
  border: 1px solid var(--line);
  font-family: var(--font-mono);
  font-size: var(--fs-12);
  font-weight: 700;
  color: var(--cyan);
}

.page-about .about-next__card h3 {
  margin: 0;
  font-family: var(--font-head);
  font-size: var(--fs-20);
  font-weight: 700;
  line-height: 1.4;
  color: var(--paper);
}

.page-about .about-next__card p {
  margin: 0;
  font-size: var(--fs-16);
  line-height: 1.8;
  color: var(--fog);
}

.page-about .about-next__go {
  margin-top: auto;
  padding-top: 12px;
  font-family: var(--font-mono);
  font-size: var(--fs-14);
  letter-spacing: 0.04em;
  color: var(--amber);
}

.page-about .about-next__aside {
  margin: 22px 0 0;
  font-size: var(--fs-16);
  line-height: 1.85;
  color: var(--fog);
}

.page-about .about-next__aside a {
  color: var(--cyan);
  text-decoration: underline;
  text-underline-offset: 3px;
}

.page-about .about-next__aside a:hover {
  color: var(--amber);
}

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

  .page-about .about-team__item:first-child {
    grid-column: 1 / -1;
  }

  .page-about .about-principles {
    grid-template-columns: repeat(3, minmax(0, 1fr));
    gap: 34px;
  }

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

@media (min-width: 900px) {
  .page-about .about-split {
    grid-template-columns: minmax(0, 1.08fr) minmax(0, 0.92fr);
    align-items: start;
    gap: clamp(28px, 4vw, 52px);
  }
}

@media (min-width: 960px) {
  .page-about .about-shell {
    grid-template-columns: var(--about-rail-w) minmax(0, 1fr);
    gap: clamp(40px, 6vw, 76px);
  }

  .page-about .about-rail__inner {
    position: sticky;
    top: calc(var(--bar-h) + 28px);
    flex-direction: column;
    align-items: flex-start;
    gap: 6px;
    overflow: visible;
    padding-bottom: 0;
  }

  .page-about .toc__title {
    display: block;
    margin-bottom: 10px;
  }

  .page-about .toc {
    flex-direction: column;
    align-self: stretch;
    gap: 0;
  }

  .page-about .toc__link {
    display: block;
    width: 100%;
    padding: 7px 0 7px 14px;
    border: 0;
    border-left: 1px solid var(--line);
    border-radius: 0;
    background: transparent;
    font-size: var(--fs-12);
  }

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

  .page-about .toc__link[aria-current="true"] {
    background: transparent;
    border-left-color: var(--cyan);
    color: var(--cyan);
  }
}

@media (prefers-reduced-motion: reduce) {
  .page-about .about-team__item,
  .page-about .about-next__card,
  .page-about .toc__link {
    transition: none;
  }

  .page-about .about-team__item:hover,
  .page-about .about-next__card:hover {
    transform: none;
  }

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