.page-about {
  --about-flow: clamp(2rem, 5vw, 3.5rem);
  --about-radius: var(--radius);
  background: var(--paper-050);
  color: var(--text-900);
  font-family: var(--font-body);
}

/* ---------- 首屏 ---------- */
.page-about .about-hero {
  position: relative;
  overflow: hidden;
  padding: clamp(1.25rem, 3vw, 2rem) 0 clamp(2.75rem, 6vw, 4.5rem);
  background:
    radial-gradient(120% 90% at 88% 8%, rgba(233, 255, 90, 0.16), rgba(11, 26, 38, 0) 55%),
    linear-gradient(158deg, var(--ink-900) 0%, var(--ink-800) 52%, var(--ink-700) 100%);
  color: var(--on-ink);
}
.page-about .about-hero::before {
  content: "";
  position: absolute;
  inset: auto -12% -30% 42%;
  height: 130%;
  background: linear-gradient(205deg, rgba(22, 121, 76, 0.55), rgba(22, 121, 76, 0) 68%);
  clip-path: polygon(38% 0, 100% 0, 100% 100%, 0 100%);
  transform: rotate(6deg);
  pointer-events: none;
}
.page-about .about-hero::after {
  content: "";
  position: absolute;
  top: 0;
  left: 0;
  width: 100%;
  height: 3px;
  background: linear-gradient(90deg, var(--whistle-300), var(--green-400) 45%, rgba(22, 121, 76, 0) 92%);
  pointer-events: none;
}
.page-about .about-hero__inner {
  position: relative;
  z-index: 1;
}
.page-about .about-hero .breadcrumb {
  margin-bottom: clamp(1.5rem, 4vw, 2.5rem);
}
.page-about .about-hero__title {
  margin: 0.6rem 0 0;
  max-width: 18em;
  font-family: var(--font-serif);
  font-weight: 700;
  font-size: clamp(1.85rem, 5.2vw, 3.4rem);
  line-height: 1.2;
  letter-spacing: -0.01em;
}
.page-about .about-hero__lead {
  margin: clamp(1rem, 2.4vw, 1.5rem) 0 0;
  max-width: 34em;
  font-size: clamp(0.95rem, 1.6vw, 1.06rem);
  line-height: 1.8;
  color: var(--on-ink-dim);
}
.page-about .about-facts {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 1px;
  margin: clamp(1.75rem, 4vw, 2.75rem) 0 0;
  padding: 0;
  list-style: none;
  background: rgba(245, 247, 244, 0.14);
  border: 1px solid rgba(245, 247, 244, 0.14);
  border-radius: var(--about-radius);
  overflow: hidden;
}
.page-about .about-facts__item {
  display: flex;
  flex-direction: column;
  gap: 0.3rem;
  padding: 0.9rem 1rem;
  background: rgba(11, 26, 38, 0.55);
}
.page-about .about-facts__num {
  font-family: var(--font-mono);
  font-variant-numeric: tabular-nums;
  font-size: clamp(1.35rem, 3vw, 1.8rem);
  font-weight: 700;
  color: var(--whistle-300);
  line-height: 1.1;
}
.page-about .about-facts__label {
  font-size: 0.78rem;
  line-height: 1.5;
  color: var(--on-ink-faint);
}

/* ---------- 说明牌标签 ---------- */
.page-about .about-label {
  display: inline-flex;
  align-items: center;
  gap: 0.55rem;
  margin: 0;
  font-family: var(--font-mono);
  font-size: 0.7rem;
  letter-spacing: 0.16em;
  text-transform: uppercase;
  color: var(--pitch-600);
}
.page-about .about-label::before {
  content: "";
  width: 22px;
  height: 1px;
  background: currentColor;
  flex: none;
}
.page-about .about-label--on-ink {
  color: var(--whistle-300);
}

/* ---------- 分栏骨架 ---------- */
.page-about .about-body {
  padding-top: clamp(1.5rem, 4vw, 2.5rem);
  padding-bottom: clamp(2rem, 5vw, 3.5rem);
}
.page-about .about-rail {
  padding-bottom: 1.25rem;
  border-bottom: 1px solid var(--line-300);
}
.page-about .rail__group + .rail__group {
  margin-top: 1rem;
}
.page-about .rail__title {
  margin: 0;
  font-family: var(--font-mono);
  font-size: 0.68rem;
  letter-spacing: 0.18em;
  text-transform: uppercase;
  color: var(--text-600);
}
.page-about .rail__list,
.page-about .rail__years {
  display: flex;
  gap: 0.4rem;
  margin: 0.55rem 0 0;
  padding: 0 0 0.2rem;
  list-style: none;
  overflow-x: auto;
  scrollbar-width: thin;
}
.page-about .rail__link {
  display: inline-flex;
  align-items: baseline;
  gap: 0.4rem;
  padding: 0.4rem 0.7rem;
  border: 1px solid var(--line-300);
  border-radius: var(--about-radius);
  color: var(--text-600);
  font-size: 0.8rem;
  text-decoration: none;
  white-space: nowrap;
  transition: color 160ms ease, border-color 160ms ease, background-color 160ms ease;
}
.page-about .rail__num {
  font-family: var(--font-mono);
  font-size: 0.7rem;
  color: var(--green-400);
}
.page-about .rail__year {
  display: inline-block;
  padding: 0.3rem 0.55rem;
  font-family: var(--font-mono);
  font-variant-numeric: tabular-nums;
  font-size: 0.75rem;
  color: var(--text-600);
  text-decoration: none;
  border-bottom: 1px solid var(--line-300);
  white-space: nowrap;
  transition: color 160ms ease, border-color 160ms ease;
}
.page-about .rail__link:hover,
.page-about .rail__link:focus-visible,
.page-about .rail__year:hover,
.page-about .rail__year:focus-visible {
  color: var(--ink-900);
  border-color: var(--pitch-600);
  background: var(--paper-100);
}
.page-about .rail__year:hover,
.page-about .rail__year:focus-visible {
  background: transparent;
  border-color: var(--whistle-600);
}

/* ---------- 章节 ---------- */
.page-about .about-sec {
  padding: var(--about-flow) 0;
  border-top: 1px solid var(--line-300);
  scroll-margin-top: 1.5rem;
}
.page-about .about-sec:first-child {
  border-top: 0;
  padding-top: 0.5rem;
}
.page-about .about-h2 {
  margin: 0.65rem 0 0;
  font-family: var(--font-serif);
  font-weight: 700;
  font-size: clamp(1.45rem, 3.4vw, 2.15rem);
  line-height: 1.3;
  letter-spacing: -0.01em;
  color: var(--text-900);
  max-width: 22em;
}
.page-about .about-prose {
  margin-top: 1.15rem;
  max-width: 36em;
}
.page-about .about-prose p {
  margin: 0 0 1rem;
  font-size: 0.98rem;
  line-height: 1.85;
  color: var(--text-600);
}
.page-about .about-prose p:last-child {
  margin-bottom: 0;
}
.page-about .about-prose--lead {
  font-size: 0.98rem;
  line-height: 1.85;
  color: var(--text-600);
}
.page-about .about-note {
  margin: 1.5rem 0 0;
  padding: 1rem 0 1rem 1.1rem;
  border-left: 3px solid var(--whistle-600);
  font-family: var(--font-serif);
  font-size: clamp(1rem, 2vw, 1.15rem);
  line-height: 1.65;
  color: var(--text-900);
  max-width: 30em;
}

/* ---------- 图文分栏 ---------- */
.page-about .about-split {
  display: grid;
  gap: clamp(1.25rem, 3vw, 2rem);
  margin-top: 1.35rem;
}
.page-about .about-split .about-prose {
  margin-top: 0;
}
.page-about .about-figure {
  margin: 0;
}
.page-about .about-frame {
  overflow: hidden;
  border-radius: var(--about-radius);
  background: var(--ink-700);
  box-shadow: inset 0 0 0 1px rgba(11, 26, 38, 0.08);
}
.page-about .about-frame--3x2 {
  aspect-ratio: 3 / 2;
}
.page-about .about-frame img {
  display: block;
  width: 100%;
  height: 100%;
  max-width: 100%;
  object-fit: cover;
}
.page-about .about-figure .figure__caption {
  margin-top: 0.6rem;
  font-family: var(--font-mono);
  font-size: 0.72rem;
  line-height: 1.6;
  color: var(--text-600);
}

/* ---------- 时间线 ---------- */
.page-about .about-zigzag {
  display: block;
  width: 100%;
  height: 34px;
  margin: 1.5rem 0 0;
  color: var(--whistle-600);
  opacity: 0.85;
}
.page-about .timeline {
  position: relative;
  margin: 1.35rem 0 0;
  padding: 0 0 0 1.5rem;
  list-style: none;
}
.page-about .timeline::before {
  content: "";
  position: absolute;
  left: 5px;
  top: 0.5rem;
  bottom: 0.6rem;
  width: 2px;
  background: linear-gradient(180deg, var(--pitch-600), var(--green-400) 55%, var(--whistle-600));
}
.page-about .tl {
  position: relative;
  padding: 0.15rem 0 1.6rem;
  scroll-margin-top: 1.5rem;
}
.page-about .tl:last-child {
  padding-bottom: 0.25rem;
}
.page-about .tl::before {
  content: "";
  position: absolute;
  left: -1.5rem;
  top: 0.62rem;
  width: 11px;
  height: 11px;
  background: var(--paper-050);
  border: 2px solid var(--pitch-600);
  transform: rotate(45deg);
  transition: background-color 160ms ease, border-color 160ms ease, transform 160ms ease;
}
.page-about .tl--warn::before {
  border-color: var(--card-amber);
}
.page-about .tl:hover::before,
.page-about .tl:focus-within::before {
  background: var(--whistle-300);
  border-color: var(--whistle-600);
  transform: rotate(45deg) scale(1.12);
}
.page-about .tl__meta {
  display: flex;
  flex-wrap: wrap;
  align-items: baseline;
  gap: 0.65rem;
  margin: 0;
}
.page-about .tl__year {
  font-family: var(--font-mono);
  font-variant-numeric: tabular-nums;
  font-size: 1.05rem;
  font-weight: 700;
  color: var(--ink-900);
}
.page-about .tl__ver {
  font-family: var(--font-mono);
  font-size: 0.7rem;
  letter-spacing: 0.08em;
  padding: 0.12rem 0.42rem;
  color: var(--pitch-600);
  border: 1px solid var(--line-300);
  border-radius: var(--about-radius);
}
.page-about .tl__title {
  margin: 0.4rem 0 0;
  font-family: var(--font-display);
  font-size: clamp(1rem, 2.2vw, 1.12rem);
  font-weight: 700;
  line-height: 1.55;
  letter-spacing: -0.01em;
  color: var(--text-900);
}
.page-about .tl__text {
  margin: 0.35rem 0 0;
  max-width: 34em;
  font-size: 0.92rem;
  line-height: 1.8;
  color: var(--text-600);
}

/* ---------- 团队展开组 ---------- */
.page-about .about-disclosures {
  display: grid;
  gap: 0.6rem;
  margin-top: clamp(1.5rem, 3vw, 2rem);
}
.page-about .disclosure {
  border: 1px solid var(--line-300);
  border-radius: var(--about-radius);
  background: #fff;
  transition: border-color 160ms ease;
}
.page-about .disclosure[data-open="true"] {
  border-color: var(--green-400);
}
.page-about .disclosure__trigger {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 1rem;
  width: 100%;
  padding: 0.9rem 1rem;
  border: 0;
  background: transparent;
  text-align: left;
  font-family: var(--font-mono);
  font-size: 0.82rem;
  font-weight: 700;
  color: var(--ink-900);
  cursor: pointer;
}
.page-about .disclosure__icon {
  flex: none;
  font-size: 1.05rem;
  line-height: 1;
  color: var(--pitch-600);
}
.page-about .disclosure__panel {
  border-top: 1px solid var(--line-300);
}
.page-about .disclosure__inner {
  padding: 0.9rem 1rem 1.05rem;
  font-size: 0.92rem;
  line-height: 1.8;
  color: var(--text-600);
}
.page-about .disclosure__inner p {
  margin: 0;
}

/* ---------- 流程步骤 ---------- */
.page-about .steps {
  margin: 0;
  padding: 0;
  list-style: none;
  display: grid;
  gap: 0.7rem;
  counter-reset: about-step;
}
.page-about .step {
  position: relative;
  padding: 0.85rem 1rem 0.95rem;
  border-left: 3px solid var(--green-400);
  background: var(--paper-100);
  border-radius: 0 var(--about-radius) var(--about-radius) 0;
}
.page-about .step:last-child {
  border-left-color: var(--whistle-600);
  background: rgba(233, 255, 90, 0.22);
}
.page-about .step__time {
  margin: 0;
  font-family: var(--font-mono);
  font-variant-numeric: tabular-nums;
  font-size: 0.72rem;
  letter-spacing: 0.08em;
  color: var(--pitch-600);
}
.page-about .step__title {
  margin: 0.3rem 0 0;
  font-family: var(--font-display);
  font-size: 1rem;
  font-weight: 700;
  letter-spacing: -0.01em;
  color: var(--ink-900);
}
.page-about .step__text {
  margin: 0.3rem 0 0;
  font-size: 0.9rem;
  line-height: 1.75;
  color: var(--text-600);
}

/* ---------- 覆盖范围 ---------- */
.page-about .cover-list {
  margin: 1.35rem 0 0;
  padding: 0;
  list-style: none;
  border-top: 1px solid var(--line-300);
}
.page-about .cover-list__row {
  display: flex;
  align-items: baseline;
  justify-content: space-between;
  gap: 1rem;
  padding: 0.7rem 0;
  border-bottom: 1px solid var(--line-300);
}
.page-about .cover-list__label {
  font-size: 0.9rem;
  line-height: 1.6;
  color: var(--text-600);
}
.page-about .cover-list__value {
  flex: none;
  font-family: var(--font-mono);
  font-variant-numeric: tabular-nums;
  font-size: 0.9rem;
  font-weight: 700;
  color: var(--ink-900);
}

/* ---------- 里程碑 ---------- */
.page-about .milestones {
  margin: 1.35rem 0 0;
  padding: 0;
  list-style: none;
  display: grid;
  gap: 1px;
  background: var(--line-300);
  border: 1px solid var(--line-300);
  border-radius: var(--about-radius);
  overflow: hidden;
}
.page-about .milestone {
  display: flex;
  flex-direction: column;
  gap: 0.25rem;
  padding: 0.95rem 1rem;
  background: var(--paper-050);
}
.page-about .milestone__year {
  font-family: var(--font-mono);
  font-variant-numeric: tabular-nums;
  font-size: 0.85rem;
  font-weight: 700;
  color: var(--pitch-600);
}
.page-about .milestone__text {
  font-size: 0.9rem;
  line-height: 1.75;
  color: var(--text-600);
}

/* ---------- 行动区 ---------- */
.page-about .about-cta {
  position: relative;
  overflow: hidden;
  background: linear-gradient(150deg, var(--ink-900), var(--ink-700));
  color: var(--on-ink);
  padding: clamp(1.75rem, 4.5vw, 3rem) 0;
}
.page-about .about-cta::before {
  content: "";
  position: absolute;
  right: -8%;
  bottom: -40%;
  width: 55%;
  height: 150%;
  background: linear-gradient(200deg, rgba(22, 121, 76, 0.5), rgba(22, 121, 76, 0) 70%);
  clip-path: polygon(30% 0, 100% 0, 100% 100%, 0 100%);
  pointer-events: none;
}
.page-about .about-cta__inner {
  position: relative;
  z-index: 1;
  display: grid;
  gap: 1.35rem;
}
.page-about .about-cta__title {
  margin: 0;
  font-family: var(--font-serif);
  font-size: clamp(1.3rem, 3vw, 1.85rem);
  line-height: 1.35;
}
.page-about .about-cta__text {
  margin: 0.7rem 0 0;
  max-width: 32em;
  font-size: 0.92rem;
  line-height: 1.8;
  color: var(--on-ink-dim);
}
.page-about .about-cta__actions {
  display: flex;
  flex-wrap: wrap;
  gap: 0.6rem;
}

/* ---------- 响应式 ---------- */
@media (min-width: 48rem) {
  .page-about .about-facts {
    grid-template-columns: repeat(4, minmax(0, 1fr));
  }
  .page-about .about-split {
    grid-template-columns: minmax(0, 1fr) minmax(0, 1fr);
    align-items: start;
  }
  .page-about .about-split--rev {
    grid-template-columns: minmax(0, 1.1fr) minmax(0, 1fr);
  }
  .page-about .about-split--tight {
    grid-template-columns: minmax(0, 1.35fr) minmax(0, 1fr);
    align-items: center;
  }
  .page-about .milestones {
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }
  .page-about .about-cta__inner {
    grid-template-columns: minmax(0, 1fr) auto;
    align-items: center;
    gap: 2rem;
  }
  .page-about .about-cta__actions {
    justify-content: flex-end;
  }
}

@media (min-width: 62rem) {
  .page-about .about-body {
    display: grid;
    grid-template-columns: minmax(0, 4fr) minmax(0, 8fr);
    gap: clamp(2rem, 4vw, 3.75rem);
    align-items: start;
  }
  .page-about .about-rail {
    position: sticky;
    top: 1.5rem;
    padding: 2.25rem 0 0;
    border-bottom: 0;
  }
  .page-about .rail__group + .rail__group {
    margin-top: 1.6rem;
  }
  .page-about .rail__list,
  .page-about .rail__years {
    flex-direction: column;
    gap: 0;
    overflow: visible;
  }
  .page-about .rail__link {
    border: 0;
    border-left: 2px solid var(--line-300);
    border-radius: 0;
    padding: 0.4rem 0 0.4rem 0.9rem;
    font-size: 0.85rem;
  }
  .page-about .rail__link:hover,
  .page-about .rail__link:focus-visible {
    background: transparent;
    border-left-color: var(--pitch-600);
    color: var(--ink-900);
  }
  .page-about .rail__year {
    border-bottom: 0;
    padding: 0.25rem 0 0.25rem 0.9rem;
    font-size: 0.78rem;
  }
  .page-about .about-sec {
    padding-top: clamp(2.25rem, 4vw, 3.25rem);
    padding-bottom: clamp(2.25rem, 4vw, 3.25rem);
  }
  .page-about .about-flow {
    padding-left: 0.5rem;
  }
}

@media (prefers-reduced-motion: reduce) {
  .page-about .tl::before,
  .page-about .rail__link,
  .page-about .rail__year,
  .page-about .disclosure {
    transition: none;
  }
}