.page-about {
  --about-rail: 216px;
  --about-rail-gap: 56px;
  --about-tick: repeating-linear-gradient(to right, var(--cyan) 0 1px, transparent 1px 8px);
  background: var(--ink);
  color: var(--read);
  min-width: 0;
}

/* ---------- 首屏 ---------- */
.page-about .about-hero {
  position: relative;
  isolation: isolate;
  padding: 40px 0 44px;
  border-bottom: 1px solid var(--grid-soft);
  overflow: hidden;
}

.page-about .about-hero::before {
  content: "";
  position: absolute;
  inset: 0;
  z-index: -1;
  background-image:
    linear-gradient(to right, rgba(58, 63, 75, 0.5) 1px, transparent 1px),
    linear-gradient(to bottom, rgba(58, 63, 75, 0.5) 1px, transparent 1px),
    radial-gradient(120% 100% at 6% 0%, rgba(122, 59, 255, 0.26), transparent 62%);
  background-size: 72px 72px, 72px 72px, 100% 100%;
  opacity: 0.6;
  pointer-events: none;
}

.page-about .about-hero__frame {
  position: relative;
  margin-top: 36px;
  padding-top: 30px;
  border-top: 1px solid var(--violet-line);
}

.page-about .about-hero__frame::before {
  content: "";
  position: absolute;
  top: -4px;
  right: 0;
  width: 72px;
  height: 7px;
  background-image: var(--about-tick);
}

.page-about .about-hero__title {
  margin: 14px 0 22px;
  font-family: var(--font-display);
  font-size: clamp(2.2rem, 8.2vw, 5.2rem);
  font-weight: 700;
  line-height: 0.98;
  letter-spacing: -0.02em;
  max-width: 18ch;
  color: var(--read);
}

.page-about .about-hero__lead {
  margin: 0;
  max-width: 62ch;
  font-size: 1rem;
  line-height: 1.85;
  color: var(--read-70);
}

.page-about .about-readout {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 1px;
  margin: 32px 0 0;
  padding: 0;
  list-style: none;
  background: var(--grid-soft);
  border: 1px solid var(--grid-soft);
}

.page-about .about-readout__item {
  display: flex;
  flex-direction: column;
  gap: 4px;
  padding: 16px 18px;
  background: var(--ink-2);
}

.page-about .about-readout__value {
  font-size: 1.6rem;
  line-height: 1;
  font-weight: 700;
  color: var(--gold);
  text-align: left;
}

.page-about .about-readout__label {
  font-size: 12px;
  letter-spacing: 0.08em;
  color: var(--read-45);
}

/* ---------- 主体栅格 ---------- */
.page-about .about-body {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 32px;
  padding: 40px 0 72px;
}

.page-about .about-sections {
  min-width: 0;
}

/* ---------- 章节索引 ---------- */
.page-about .about-rail {
  min-width: 0;
}

.page-about .about-rail__caption {
  margin: 0 0 10px;
  color: var(--read-45);
}

.page-about .about-rail__list {
  display: flex;
  gap: 8px;
  margin: 0;
  padding: 0 0 10px;
  list-style: none;
  overflow-x: auto;
  scrollbar-width: thin;
}

.page-about .about-rail__item {
  flex: 0 0 auto;
}

.page-about .about-rail__link {
  display: flex;
  align-items: baseline;
  gap: 8px;
  padding: 8px 12px;
  border: 1px solid var(--grid);
  color: var(--read-70);
  font-size: 13px;
  line-height: 1.4;
  text-decoration: none;
  white-space: nowrap;
  border-radius: var(--radius);
  transition: color 160ms ease, border-color 160ms ease, background-color 160ms ease;
}

.page-about .about-rail__num {
  font-size: 11px;
  letter-spacing: 0.1em;
  color: var(--violet);
}

.page-about .about-rail__link:hover,
.page-about .about-rail__link:focus-visible {
  color: var(--read);
  border-color: var(--cyan);
  background: var(--cyan-soft);
}

.page-about .about-rail__link:focus-visible {
  outline: 2px solid var(--cyan);
  outline-offset: 2px;
}

/* ---------- 章节 ---------- */
.page-about .about-sec {
  min-width: 0;
  padding: 44px 0;
  border-bottom: 1px solid var(--grid-soft);
  scroll-margin-top: 132px;
}

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

.page-about .about-sec__head {
  margin-bottom: 26px;
}

.page-about .about-sec__head .index-label {
  color: var(--violet);
  margin: 0 0 10px;
}

.page-about .about-sec__title {
  margin: 0;
  font-family: var(--font-display);
  font-size: clamp(1.5rem, 5.4vw, 2.5rem);
  font-weight: 700;
  line-height: 1.08;
  letter-spacing: -0.02em;
  color: var(--read);
}

.page-about .about-sec__lead {
  margin: 14px 0 0;
  max-width: 60ch;
  font-size: 0.95rem;
  line-height: 1.8;
  color: var(--read-70);
}

.page-about .about-sec .prose p {
  margin: 0 0 16px;
  color: var(--read-70);
}

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

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

/* ---------- 双轨对照 ---------- */
.page-about .about-track-pair {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 1px;
  margin: 28px 0 0;
  padding: 1px;
  background: var(--grid-soft);
  border: 1px solid var(--grid-soft);
}

.page-about .about-track-pair__col {
  padding: 20px 18px;
  background: var(--panel);
}

.page-about .about-track-pair dt {
  margin: 0 0 8px;
  color: var(--cyan);
}

.page-about .about-track-pair dd {
  margin: 0;
  font-family: var(--font-display);
  font-size: 1.05rem;
  letter-spacing: 0.02em;
  color: var(--read);
}

/* ---------- 暖纸色宽章节 ---------- */
.page-about .about-sec--paper {
  padding: 0;
  margin: 20px 0;
  border-bottom: 0;
}

.page-about .about-paper {
  position: relative;
  padding: 44px 22px;
  background: var(--paper);
  color: var(--paper-ink);
  border-top: 1px solid var(--paper-ink);
  border-bottom: 1px solid var(--paper-ink);
}

.page-about .about-paper::before {
  content: "";
  position: absolute;
  top: -4px;
  left: 0;
  width: 100%;
  height: 7px;
  background-image: repeating-linear-gradient(to right, rgba(26, 26, 34, 0.4) 0 1px, transparent 1px 10px);
}

.page-about .about-paper .index-label {
  color: rgba(26, 26, 34, 0.6);
}

.page-about .about-paper .about-sec__head .index-label {
  color: rgba(26, 26, 34, 0.7);
}

.page-about .about-paper .about-sec__title {
  color: var(--paper-ink);
}

.page-about .about-paper .about-sec__lead {
  color: rgba(26, 26, 34, 0.78);
}

/* ---------- 图片位 ---------- */
.page-about .about-figure {
  margin: 26px 0 30px;
}

.page-about .about-figure .media-frame {
  border: 1px solid var(--grid);
  border-radius: var(--radius);
}

.page-about .about-paper .about-figure .media-frame {
  border-color: rgba(26, 26, 34, 0.35);
}

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

/* ---------- 原则折叠清单 ---------- */
.page-about .about-principles {
  margin-top: 8px;
}

.page-about .about-principle {
  border-top: 1px solid rgba(26, 26, 34, 0.28);
  transition: box-shadow 180ms ease;
}

.page-about .about-principle:last-of-type {
  border-bottom: 1px solid rgba(26, 26, 34, 0.28);
}

.page-about .about-principle[open] {
  box-shadow: inset 3px 0 0 var(--cyan);
}

.page-about .about-principle summary {
  position: relative;
  display: flex;
  flex-wrap: wrap;
  align-items: baseline;
  gap: 12px;
  padding: 18px 42px 18px 12px;
  cursor: pointer;
  list-style: none;
}

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

.page-about .about-principle summary::after {
  content: "+";
  position: absolute;
  right: 10px;
  top: 50%;
  transform: translateY(-50%);
  font-family: var(--font-mono);
  font-size: 18px;
  line-height: 1;
  color: rgba(26, 26, 34, 0.6);
}

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

.page-about .about-principle summary:focus-visible {
  outline: 2px solid var(--cyan);
  outline-offset: -2px;
}

.page-about .about-principle__num {
  font-size: 11px;
  letter-spacing: 0.12em;
  color: rgba(26, 26, 34, 0.55);
}

.page-about .about-principle__name {
  font-family: var(--font-display);
  font-size: 1.15rem;
  font-weight: 700;
  letter-spacing: -0.01em;
  color: var(--paper-ink);
}

.page-about .about-principle__body {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 18px;
  padding: 0 12px 24px;
}

.page-about .about-principle__note p {
  margin: 8px 0 0;
  font-size: 0.94rem;
  line-height: 1.8;
  color: rgba(26, 26, 34, 0.86);
}

/* ---------- 团队分工 ---------- */
.page-about .about-team {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 28px;
}

.page-about .about-figure--tall {
  margin: 0;
}

.page-about .about-team__body .prose p {
  margin: 0 0 16px;
  color: var(--read-70);
}

.page-about .about-roles {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 1px;
  margin: 24px 0;
  padding: 1px;
  list-style: none;
  background: var(--grid-soft);
  border: 1px solid var(--grid-soft);
}

.page-about .about-role {
  padding: 18px;
  background: var(--panel);
  transition: transform 160ms ease, box-shadow 160ms ease;
}

.page-about .about-role:hover {
  transform: translateY(-2px);
  box-shadow: 0 0 0 1px var(--violet-line), 0 8px 24px rgba(122, 59, 255, 0.14);
}

.page-about .about-role__name {
  margin: 0 0 8px;
  font-family: var(--font-display);
  font-size: 1.02rem;
  font-weight: 700;
  letter-spacing: 0.01em;
  color: var(--read);
}

.page-about .about-role__desc {
  margin: 0;
  font-size: 0.9rem;
  line-height: 1.75;
  color: var(--read-70);
}

/* ---------- 里程碑时间轴 ---------- */
.page-about .about-timeline {
  position: relative;
  margin: 30px 0 0;
  padding: 4px 0 4px 30px;
  list-style: none;
}

.page-about .about-timeline::before {
  content: "";
  position: absolute;
  left: 2px;
  top: 6px;
  bottom: 6px;
  width: 7px;
  background-image: linear-gradient(to bottom, var(--cyan) 0 1px, transparent 1px 9px);
  background-size: 7px 9px;
  opacity: 0.5;
  transform: skewX(-8deg);
  transform-origin: top center;
}

.page-about .about-timeline__item {
  position: relative;
  padding: 0 0 30px;
}

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

.page-about .about-timeline__item::before {
  content: "";
  position: absolute;
  left: -30px;
  top: 6px;
  width: 9px;
  height: 9px;
  background: var(--ink);
  border: 1px solid var(--cyan);
  transform: rotate(45deg) translateX(-1px);
}

.page-about .about-timeline__item--now::before {
  background: var(--gold);
  border-color: var(--gold);
  box-shadow: 0 0 0 4px rgba(255, 166, 43, 0.16);
}

.page-about .about-timeline__stage {
  display: block;
  font-size: 11px;
  letter-spacing: 0.12em;
  color: var(--read-45);
  margin-bottom: 6px;
}

.page-about .about-timeline__item--now .about-timeline__stage {
  color: var(--gold);
}

.page-about .about-timeline__title {
  margin: 0 0 8px;
  font-family: var(--font-display);
  font-size: 1.1rem;
  font-weight: 700;
  letter-spacing: 0.01em;
  color: var(--read);
}

.page-about .about-timeline__desc {
  margin: 0;
  max-width: 62ch;
  font-size: 0.9rem;
  line-height: 1.8;
  color: var(--read-70);
}

/* ---------- 内容边界 ---------- */
.page-about .about-limits {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 1px;
  margin: 24px 0 0;
  padding: 1px;
  list-style: none;
  background: var(--grid-soft);
  border: 1px solid var(--grid-soft);
}

.page-about .about-limit {
  display: grid;
  gap: 10px;
  padding: 18px;
  background: var(--ink-2);
}

.page-about .about-limit p {
  margin: 0;
  font-size: 0.92rem;
  line-height: 1.8;
  color: var(--read-70);
}

.page-about .about-limit .tag {
  justify-self: start;
}

/* ---------- 合作与授权 ---------- */
.page-about .about-cta {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
  margin-top: 28px;
}

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

  .page-about .about-paper {
    padding: 52px 40px;
  }

  .page-about .about-principle__body {
    grid-template-columns: repeat(2, minmax(0, 1fr));
    gap: 28px;
  }

  .page-about .about-track-pair {
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }

  .page-about .about-roles {
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }
}

@media (min-width: 900px) {
  .page-about .about-hero {
    padding: 56px 0 64px;
  }

  .page-about .about-team {
    grid-template-columns: minmax(0, 0.78fr) minmax(0, 1.22fr);
    gap: 40px;
    align-items: start;
  }

  .page-about .about-figure--tall {
    margin: 0 0 12px;
  }
}

@media (min-width: 1024px) {
  .page-about .about-body {
    grid-template-columns: var(--about-rail) minmax(0, 1fr);
    gap: var(--about-rail-gap);
    padding: 64px 0 112px;
  }

  .page-about .about-rail {
    position: sticky;
    top: 148px;
  }

  .page-about .about-rail__list {
    flex-direction: column;
    gap: 0;
    padding: 0;
    overflow: visible;
    border-left: 1px solid var(--grid-soft);
  }

  .page-about .about-rail__link {
    border: 0;
    border-left: 2px solid transparent;
    margin-left: -1px;
    padding: 10px 0 10px 14px;
    white-space: normal;
    background: transparent;
    border-radius: 0;
  }

  .page-about .about-rail__link:hover,
  .page-about .about-rail__link:focus-visible {
    background: var(--cyan-soft);
    border-left-color: var(--cyan);
    border-color: transparent;
    border-left-color: var(--cyan);
  }

  .page-about .about-sec {
    padding: 56px 0;
    scroll-margin-top: 156px;
  }

  .page-about .about-sec--paper {
    padding: 0;
    margin: 24px 0;
  }

  .page-about .about-paper {
    padding: 64px 56px;
  }

  .page-about .about-hero__title {
    max-width: 15ch;
  }
}

@media (prefers-reduced-motion: reduce) {
  .page-about .about-role,
  .page-about .about-rail__link,
  .page-about .about-principle {
    transition: none;
  }

  .page-about .about-role:hover {
    transform: none;
  }
}
</final>
</PAGE_CSS>