.page-about {
  --about-pad: clamp(1rem, 4vw, 2.5rem);
  --about-rail: 9.5rem;
  background: var(--ink-900);
  color: var(--mist);
  font-family: var(--font-body);
  font-size: 1rem;
  line-height: 1.75;
}

.page-about h1,
.page-about h2,
.page-about h3 {
  font-family: var(--font-head);
  font-weight: 900;
  letter-spacing: -0.02em;
  line-height: 1.14;
  color: var(--white);
  margin: 0;
}

.page-about p {
  margin: 0;
}

/* ---------- 首屏 ---------- */
.page-about .about-hero {
  position: relative;
  padding: clamp(1.4rem, 5vw, 3.4rem) 0 clamp(2rem, 5vw, 3.4rem);
  border-bottom: 1px solid var(--line);
}

.page-about .about-hero::before {
  content: "";
  position: absolute;
  top: -34%;
  right: -22%;
  width: min(680px, 118vw);
  height: min(680px, 118vw);
  background: radial-gradient(circle at 50% 50%, rgba(255, 107, 74, 0.2), rgba(79, 224, 193, 0.08) 46%, transparent 68%);
  pointer-events: none;
  z-index: 0;
}

.page-about .about-hero__grid {
  position: relative;
  z-index: 1;
  max-width: var(--shell);
  margin-inline: auto;
  padding-inline: var(--about-pad);
  display: grid;
  grid-template-columns: 1fr;
  gap: clamp(1.6rem, 4vw, 3rem);
  align-items: center;
}

.page-about .about-crumb {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 0.5rem;
  font-family: var(--font-mono);
  font-size: 0.75rem;
  letter-spacing: 0.06em;
  margin-bottom: 1.2rem;
}

.page-about .about-crumb a {
  color: var(--mint);
  text-decoration: none;
}

.page-about .about-crumb a:hover,
.page-about .about-crumb a:focus-visible {
  text-decoration: underline;
  text-underline-offset: 0.25em;
}

.page-about .about-crumb__sep {
  color: rgba(184, 199, 209, 0.5);
}

.page-about .about-kicker {
  font-family: var(--font-mono);
  font-size: 0.72rem;
  letter-spacing: 0.16em;
  color: var(--sand);
  margin-bottom: 0.9rem;
}

.page-about .about-hero__title {
  font-size: clamp(2.1rem, 6.6vw, 4.4rem);
  margin-bottom: 1.1rem;
  text-wrap: balance;
}

.page-about .about-hero__lead {
  max-width: 34em;
  font-size: clamp(1rem, 1.6vw, 1.125rem);
  line-height: 1.8;
  margin-bottom: 1.6rem;
}

.page-about .about-hero__actions {
  display: flex;
  flex-wrap: wrap;
  gap: 0.7rem;
  margin-bottom: 1.9rem;
}

.page-about .about-hero__facts {
  list-style: none;
  margin: 0;
  padding: 0;
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 1px;
  background: var(--line);
  border: 1px solid var(--line);
  border-radius: var(--radius);
  overflow: hidden;
}

.page-about .about-hero__facts li {
  background: var(--ink-800);
  padding: 0.85rem 1rem;
}

.page-about .about-hero__facts strong {
  display: block;
  font-family: var(--font-head);
  font-weight: 900;
  font-size: clamp(1.4rem, 3vw, 1.9rem);
  color: var(--white);
  line-height: 1.1;
}

.page-about .about-hero__facts span {
  font-size: 0.78rem;
  letter-spacing: 0.03em;
  color: var(--mist);
}

.page-about .about-hero__visual {
  margin: 0;
  border: 2px solid var(--line-strong);
  border-radius: var(--radius);
  box-shadow: var(--shadow-card);
  background: var(--ink-800);
  overflow: hidden;
}

.page-about .about-hero__visual img {
  display: block;
  width: 100%;
  height: auto;
  object-fit: cover;
}

.page-about .about-hero__visual figcaption {
  font-family: var(--font-mono);
  font-size: 0.72rem;
  letter-spacing: 0.04em;
  color: var(--sand);
  padding: 0.65rem 0.9rem;
  border-top: 1px solid var(--line);
}

/* ---------- 骨架：侧边轨道 + 正文 ---------- */
.page-about .about-shell {
  max-width: var(--shell);
  margin-inline: auto;
  padding: clamp(1.4rem, 4vw, 3rem) var(--about-pad) clamp(2.4rem, 6vw, 4.5rem);
  display: grid;
  grid-template-columns: 1fr;
  gap: clamp(1.2rem, 3vw, 2.6rem);
  align-items: start;
}

.page-about .about-rail {
  border-bottom: 1px solid var(--line);
  padding-bottom: 0.9rem;
}

.page-about .about-rail__title {
  display: none;
  font-family: var(--font-mono);
  font-size: 0.7rem;
  letter-spacing: 0.16em;
  color: var(--sand);
  margin-bottom: 0.8rem;
}

.page-about .about-rail__list {
  list-style: none;
  margin: 0;
  padding: 0 0 0.35rem;
  display: flex;
  gap: 0.45rem;
  overflow-x: auto;
}

.page-about .about-rail__link {
  display: inline-flex;
  align-items: center;
  gap: 0.4rem;
  white-space: nowrap;
  font-family: var(--font-mono);
  font-size: 0.72rem;
  letter-spacing: 0.05em;
  color: var(--mist);
  text-decoration: none;
  border: 1px solid var(--line);
  border-radius: 999px;
  padding: 0.35rem 0.65rem;
  transition: color 0.2s ease, border-color 0.2s ease;
}

.page-about .about-rail__dot {
  width: 0.4rem;
  height: 0.4rem;
  border-radius: 50%;
  background: var(--coral);
  flex: none;
}

.page-about .about-rail__link:hover,
.page-about .about-rail__link:focus-visible {
  color: var(--white);
  border-color: var(--mint);
}

.page-about .about-body {
  min-width: 0;
  display: grid;
  gap: clamp(1.6rem, 4vw, 3rem);
}

/* ---------- 章节 ---------- */
.page-about .about-sec {
  padding-block: clamp(1.4rem, 3.5vw, 2.6rem);
}

.page-about .about-sec__index {
  font-family: var(--font-mono);
  font-size: 0.75rem;
  letter-spacing: 0.14em;
  color: var(--sand);
  margin-bottom: 0.7rem;
}

.page-about .about-sec__index--dark {
  color: var(--ink-700);
}

.page-about .about-sec__title {
  font-size: clamp(1.6rem, 3.8vw, 2.5rem);
  margin-bottom: 0.9rem;
  text-wrap: balance;
}

.page-about .about-sec__lead {
  max-width: 42em;
  margin-bottom: 1.6rem;
}

.page-about .about-sec__tail {
  margin-top: 1.4rem;
}

.page-about .about-inline-link {
  font-family: var(--font-mono);
  font-size: 0.85rem;
  letter-spacing: 0.04em;
  color: var(--mint);
  text-decoration: none;
  border-bottom: 1px solid rgba(79, 224, 193, 0.45);
  padding-bottom: 0.15rem;
  transition: color 0.2s ease, border-color 0.2s ease;
}

.page-about .about-inline-link:hover,
.page-about .about-inline-link:focus-visible {
  color: var(--coral-neon);
  border-bottom-color: var(--coral-neon);
}

/* ---------- 时间轴 ---------- */
.page-about .about-tl {
  list-style: none;
  margin: 0;
  padding: 0;
  position: relative;
  display: grid;
  gap: 0.9rem;
}

.page-about .about-tl::before {
  content: "";
  position: absolute;
  left: 0.32rem;
  top: 0.8rem;
  bottom: 0.8rem;
  width: 2px;
  background: linear-gradient(180deg, var(--coral), var(--mint) 55%, rgba(184, 199, 209, 0.14));
}

.page-about .about-tl__item {
  position: relative;
  padding-left: 1.9rem;
}

.page-about .about-tl__item::before {
  content: "";
  position: absolute;
  left: 0;
  top: 0.9rem;
  width: 0.72rem;
  height: 0.72rem;
  border-radius: 50%;
  background: var(--ink-900);
  border: 2px solid var(--coral);
  box-shadow: 0 0 0 4px rgba(255, 107, 74, 0.14);
}

.page-about .about-tl__card {
  background: var(--ink-800);
  border: 2px solid var(--line);
  border-left: 3px solid rgba(79, 224, 193, 0.55);
  border-radius: var(--radius);
  padding: 1rem 1.1rem;
  transition: transform 0.25s ease, border-color 0.25s ease, box-shadow 0.25s ease;
}

.page-about .about-tl__card:hover,
.page-about .about-tl__card:focus-within {
  transform: translateX(3px);
  border-color: var(--line-strong);
  border-left-color: var(--coral);
  box-shadow: 0 12px 28px rgba(0, 0, 0, 0.28);
}

.page-about .about-tl__year {
  display: block;
  font-family: var(--font-mono);
  font-size: 1.05rem;
  letter-spacing: 0.06em;
  color: var(--mint);
  margin-bottom: 0.35rem;
}

.page-about .about-tl__card h3 {
  font-size: 1.08rem;
  margin-bottom: 0.4rem;
}

.page-about .about-tl__card p {
  font-size: 0.94rem;
  line-height: 1.72;
}

/* ---------- 服务范围 ---------- */
.page-about .about-scope {
  display: grid;
  grid-template-columns: 1fr;
  gap: 1.4rem;
}

.page-about .about-figure {
  margin: 0 0 1.4rem;
  border: 2px solid var(--line-strong);
  border-radius: var(--radius);
  box-shadow: var(--shadow-card);
  background: var(--ink-800);
  overflow: hidden;
}

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

.page-about .about-figure figcaption {
  font-family: var(--font-mono);
  font-size: 0.72rem;
  letter-spacing: 0.04em;
  color: var(--sand);
  padding: 0.6rem 0.85rem;
  border-top: 1px solid var(--line);
}

.page-about .about-figure--wide {
  margin: 1.8rem 0 0;
}

.page-about .about-scenes {
  list-style: none;
  margin: 0;
  padding: 0;
  display: grid;
  grid-template-columns: 1fr;
  gap: 0.8rem;
}

.page-about .about-scenes li {
  background: rgba(14, 47, 74, 0.62);
  border: 1px solid var(--line);
  border-left: 3px solid var(--mint);
  border-radius: var(--radius);
  padding: 0.85rem 1rem;
  transition: border-left-color 0.22s ease, background 0.22s ease;
}

.page-about .about-scenes li:hover {
  border-left-color: var(--coral);
  background: rgba(18, 62, 92, 0.78);
}

.page-about .about-scenes h3 {
  font-size: 1rem;
  margin-bottom: 0.3rem;
}

.page-about .about-scenes p {
  font-size: 0.9rem;
  line-height: 1.7;
}

/* ---------- 分类归档（浅色档案面板） ---------- */
.page-about .about-panel {
  background: var(--paper);
  color: var(--ink-800);
  border: 2px solid var(--ink-700);
  border-radius: var(--radius);
  box-shadow: var(--shadow-card);
  padding: clamp(1.2rem, 3.4vw, 2.2rem);
}

.page-about .about-panel h2,
.page-about .about-panel h3 {
  color: var(--ink-900);
}

.page-about .about-panel__lead {
  max-width: 40em;
  margin-bottom: 1.4rem;
  font-size: 0.98rem;
}

.page-about .about-panel__note {
  margin-top: 1.3rem;
  padding-top: 1rem;
  border-top: 1px dashed rgba(7, 26, 43, 0.22);
  font-size: 0.88rem;
  color: var(--ink-700);
}

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

.page-about .about-index__row {
  display: grid;
  grid-template-columns: auto minmax(0, 1fr);
  gap: 0.9rem;
  align-items: start;
  padding: 0.95rem 0;
  border-top: 1px solid rgba(7, 26, 43, 0.14);
}

.page-about .about-index__row:last-child {
  border-bottom: 1px solid rgba(7, 26, 43, 0.14);
}

.page-about .about-index__num {
  font-family: var(--font-mono);
  font-size: 0.72rem;
  letter-spacing: 0.04em;
  background: var(--ink-900);
  color: var(--paper);
  padding: 0.22rem 0.45rem;
  border-radius: 2px;
  white-space: nowrap;
}

.page-about .about-index__row h3 {
  font-size: 1rem;
  margin-bottom: 0.25rem;
}

.page-about .about-index__row p {
  font-size: 0.9rem;
  line-height: 1.7;
  color: var(--ink-700);
}

/* ---------- 维护团队 ---------- */
.page-about .about-team__figure {
  display: flex;
  align-items: baseline;
  gap: 0.9rem;
  border-left: 4px solid var(--coral);
  padding-left: 1rem;
  margin-bottom: 1.4rem;
}

.page-about .about-team__figure strong {
  font-family: var(--font-head);
  font-weight: 900;
  font-size: clamp(2.8rem, 8vw, 4.4rem);
  line-height: 0.95;
  color: var(--white);
  letter-spacing: -0.03em;
}

.page-about .about-team__figure span {
  font-size: 0.86rem;
  line-height: 1.6;
  color: var(--mist);
}

.page-about .about-details {
  border-top: 2px solid var(--line-strong);
}

.page-about .about-detail {
  border-bottom: 1px solid var(--line);
}

.page-about .about-detail > summary {
  list-style: none;
  cursor: pointer;
  display: flex;
  align-items: center;
  gap: 0.8rem;
  padding: 0.9rem 0.2rem;
  transition: background 0.2s ease;
}

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

.page-about .about-detail > summary:hover {
  background: rgba(18, 62, 92, 0.42);
}

.page-about .about-detail > summary::after {
  content: "+";
  font-family: var(--font-mono);
  font-size: 1.1rem;
  line-height: 1;
  color: var(--coral);
  margin-left: 0.6rem;
}

.page-about .about-detail[open] > summary::after {
  content: "−";
  color: var(--mint);
}

.page-about .about-detail__name {
  font-family: var(--font-head);
  font-weight: 900;
  font-size: 1.05rem;
  letter-spacing: -0.01em;
  color: var(--white);
}

.page-about .about-detail__meta {
  margin-left: auto;
  font-family: var(--font-mono);
  font-size: 0.72rem;
  letter-spacing: 0.05em;
  color: var(--sand);
  border: 1px solid rgba(242, 196, 109, 0.4);
  border-radius: 999px;
  padding: 0.15rem 0.55rem;
  white-space: nowrap;
}

.page-about .about-detail__body {
  padding: 0 0.2rem 1rem;
}

.page-about .about-detail__body p {
  font-size: 0.92rem;
  line-height: 1.75;
  max-width: 44em;
  color: var(--mist);
}

/* ---------- 版本档案 ---------- */
.page-about .about-steps {
  list-style: none;
  margin: 0;
  padding: 0;
  display: grid;
  grid-template-columns: 1fr;
  gap: 0.9rem;
  counter-reset: step;
}

.page-about .about-steps li {
  position: relative;
  background: linear-gradient(160deg, rgba(18, 62, 92, 0.9), rgba(7, 26, 43, 0.9));
  border: 2px solid var(--line);
  border-radius: var(--radius);
  padding: 1rem 1.1rem;
  transition: border-color 0.22s ease;
}

.page-about .about-steps li:hover {
  border-color: rgba(242, 196, 109, 0.55);
}

.page-about .about-steps__num {
  display: block;
  font-family: var(--font-mono);
  font-size: 0.78rem;
  letter-spacing: 0.14em;
  color: var(--sand);
  margin-bottom: 0.5rem;
}

.page-about .about-steps h3 {
  font-size: 1.05rem;
  margin-bottom: 0.35rem;
}

.page-about .about-steps p {
  font-size: 0.9rem;
  line-height: 1.72;
}

/* ---------- 收尾 ---------- */
.page-about .about-cta {
  margin-top: clamp(0.5rem, 2vw, 1.2rem);
}

.page-about .about-cta__box {
  background: linear-gradient(140deg, rgba(255, 107, 74, 0.18), rgba(79, 224, 193, 0.12) 55%, rgba(14, 47, 74, 0.9));
  border: 2px solid var(--line-strong);
  border-radius: var(--radius);
  box-shadow: var(--shadow-deep);
  padding: clamp(1.3rem, 3.5vw, 2.3rem);
}

.page-about .about-cta__box h2 {
  font-size: clamp(1.5rem, 3.4vw, 2.2rem);
  margin-bottom: 0.8rem;
}

.page-about .about-cta__box p {
  max-width: 40em;
  font-size: 0.96rem;
  margin-bottom: 1.3rem;
}

.page-about .about-cta__actions {
  display: flex;
  flex-wrap: wrap;
  gap: 0.7rem;
}

/* ---------- 响应式 ---------- */
@media (min-width: 640px) {
  .page-about .about-hero__facts {
    grid-template-columns: repeat(4, minmax(0, 1fr));
  }
}

@media (min-width: 700px) {
  .page-about .about-scenes {
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }

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

@media (min-width: 900px) {
  .page-about .about-hero__grid {
    grid-template-columns: minmax(0, 1.05fr) minmax(0, 0.95fr);
  }

  .page-about .about-scope {
    grid-template-columns: minmax(0, 1.05fr) minmax(0, 1fr);
    gap: 2rem;
    align-items: start;
  }

  .page-about .about-tl {
    gap: 0.8rem;
  }

  .page-about .about-tl__item:nth-child(even) {
    margin-left: clamp(1rem, 4vw, 3rem);
  }

  .page-about .about-tl__item:nth-child(odd) {
    margin-right: clamp(1rem, 4vw, 3rem);
  }
}

@media (min-width: 1024px) {
  .page-about .about-shell {
    grid-template-columns: var(--about-rail) minmax(0, 1fr);
  }

  .page-about .about-rail {
    position: sticky;
    top: 5.5rem;
    border-bottom: 0;
    border-left: 1px solid var(--line);
    padding: 0 0 0 0.9rem;
  }

  .page-about .about-rail__title {
    display: block;
  }

  .page-about .about-rail__list {
    flex-direction: column;
    gap: 0.15rem;
    overflow: visible;
    padding-bottom: 0;
  }

  .page-about .about-rail__link {
    border: 0;
    border-radius: 0;
    padding: 0.45rem 0;
    font-size: 0.75rem;
  }

  .page-about .about-rail__dot {
    width: 0.35rem;
    height: 0.35rem;
    background: rgba(184, 199, 209, 0.5);
    transition: background 0.2s ease;
  }

  .page-about .about-rail__link:hover .about-rail__dot,
  .page-about .about-rail__link:focus-visible .about-rail__dot {
    background: var(--coral);
  }
}

@media (prefers-reduced-motion: reduce) {
  .page-about .about-tl__card,
  .page-about .about-scenes li,
  .page-about .about-steps li,
  .page-about .about-rail__link,
  .page-about .about-inline-link {
    transition: none;
  }

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