.page-about {
  --about-rule: 2px solid var(--steel);
  --about-index-w: 178px;
  padding-bottom: clamp(48px, 8vw, 96px);
}

/* ---------- 首屏 ---------- */
.page-about .about-intro {
  padding-top: clamp(96px, 15vw, 172px);
  padding-bottom: clamp(28px, 4vw, 44px);
}

.page-about .about-intro .crumbs {
  margin-bottom: clamp(20px, 3vw, 32px);
}

.page-about .about-intro h1 {
  font-family: var(--font-display);
  font-weight: 900;
  font-size: clamp(34px, 6vw, 68px);
  line-height: 1.08;
  letter-spacing: -0.03em;
  color: var(--white);
  margin: 12px 0 0;
  max-width: 20ch;
}

.page-about .about-lede {
  margin: clamp(18px, 2.4vw, 26px) 0 0;
  max-width: 68ch;
  font-size: var(--fs-md);
  line-height: 1.75;
  color: var(--muted);
}

.page-about .about-facts {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 2px;
  background: var(--steel);
  border: var(--about-rule);
  list-style: none;
  margin: clamp(26px, 4vw, 42px) 0 0;
  padding: 0;
}

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

.page-about .about-facts .num {
  display: block;
  font-family: var(--font-mono);
  font-size: clamp(30px, 4.6vw, 50px);
  font-weight: 700;
  line-height: 1;
  letter-spacing: -0.02em;
  color: var(--cyan);
  font-variant-numeric: tabular-nums;
}

.page-about .about-facts em {
  display: block;
  margin-top: 10px;
  font-style: normal;
  font-size: var(--fs-sm);
  line-height: 1.55;
  color: var(--muted);
}

/* ---------- 全幅图 ---------- */
.page-about .about-plate {
  margin: 0 0 clamp(36px, 5vw, 64px);
}

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

/* ---------- 章节骨架 ---------- */
.page-about .chapter-layout {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: clamp(24px, 4vw, 40px);
  align-items: start;
}

.page-about .chapter-index {
  border-top: var(--about-rule);
  border-bottom: var(--about-rule);
  padding: 10px 0;
  min-width: 0;
}

.page-about .chapter-index-title {
  font-family: var(--font-mono);
  font-size: var(--fs-xs);
  letter-spacing: 0.2em;
  text-transform: uppercase;
  color: var(--muted);
  margin: 0 0 8px;
}

.page-about .chapter-index-list {
  display: flex;
  gap: 4px;
  list-style: none;
  margin: 0;
  padding: 0 0 4px;
  overflow-x: auto;
  scrollbar-width: thin;
}

.page-about .chapter-index-list li {
  flex: 0 0 auto;
}

.page-about .chapter-index-list a {
  display: flex;
  align-items: baseline;
  gap: 8px;
  white-space: nowrap;
  padding: 8px 10px;
  border-left: 2px solid transparent;
  font-size: var(--fs-sm);
  color: var(--muted);
  text-decoration: none;
  transition: color 180ms var(--ease), background-color 180ms var(--ease), border-color 180ms var(--ease);
}

.page-about .chapter-index-list a:hover,
.page-about .chapter-index-list a:focus-visible {
  color: var(--white);
  background: rgba(0, 229, 208, 0.09);
  border-left-color: var(--cyan);
}

.page-about .idx-num {
  font-family: var(--font-mono);
  font-size: var(--fs-xs);
  letter-spacing: 0.06em;
  color: var(--cyan);
  font-variant-numeric: tabular-nums;
}

.page-about .chapter-stream {
  display: flex;
  flex-direction: column;
  gap: clamp(28px, 4.5vw, 56px);
  min-width: 0;
}

/* ---------- 单个章节 ---------- */
.page-about .chapter {
  position: relative;
  background: var(--panel);
  border: var(--about-rule);
  border-left: 4px solid var(--steel);
  box-shadow: var(--lift-sm);
  padding: clamp(20px, 3vw, 38px);
  scroll-margin-top: 112px;
}

.page-about .chapter--plain {
  background: var(--deep);
  border-left-color: var(--cyan);
}

.page-about .chapter-head {
  display: flex;
  flex-wrap: wrap;
  align-items: baseline;
  gap: 6px 18px;
  padding-bottom: 16px;
  border-bottom: var(--about-rule);
  margin-bottom: clamp(18px, 2.4vw, 28px);
}

.page-about .chapter-num {
  font-family: var(--font-display);
  font-weight: 900;
  font-size: clamp(38px, 6vw, 72px);
  line-height: 0.78;
  letter-spacing: -0.05em;
  color: var(--steel);
}

@supports (-webkit-text-stroke: 1px currentColor) {
  .page-about .chapter-num {
    color: transparent;
    -webkit-text-stroke: 2px var(--steel);
    transition: -webkit-text-stroke-color 240ms var(--ease);
  }
  .page-about .chapter:hover .chapter-num {
    -webkit-text-stroke-color: var(--cyan);
  }
}

.page-about .chapter-head h2 {
  flex: 1 1 16ch;
  margin: 0;
  font-family: var(--font-display);
  font-weight: 900;
  font-size: var(--fs-lg);
  line-height: 1.2;
  letter-spacing: -0.02em;
  color: var(--white);
}

.page-about .chapter-body > p {
  margin: 0 0 1.15em;
  max-width: 70ch;
  font-size: var(--fs-base);
  line-height: 1.75;
  color: var(--muted);
}

.page-about .chapter-body > p:last-child {
  margin-bottom: 0;
}

.page-about .chapter-outro {
  margin-top: 1.4em !important;
}

/* ---------- 原则三条 ---------- */
.page-about .principles {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 14px;
  margin-top: clamp(20px, 3vw, 30px);
}

.page-about .principle {
  background: var(--deep);
  border-top: 4px solid var(--cyan);
  padding: 18px 18px 20px;
}

.page-about .principle:nth-child(2) {
  border-top-color: var(--orange);
}

.page-about .principle:nth-child(3) {
  border-top-color: var(--steel);
}

.page-about .principle-mark {
  font-family: var(--font-mono);
  font-size: var(--fs-xs);
  letter-spacing: 0.22em;
  color: var(--muted);
  margin: 0 0 10px;
}

.page-about .principle h3 {
  margin: 0 0 10px;
  font-family: var(--font-display);
  font-weight: 800;
  font-size: var(--fs-md);
  line-height: 1.35;
  color: var(--white);
}

.page-about .principle p:last-child {
  margin: 0;
  font-size: var(--fs-sm);
  line-height: 1.7;
  color: var(--muted);
}

/* ---------- 双主线 ---------- */
.page-about .twin-line {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 2px;
  background: var(--steel);
  border: var(--about-rule);
  margin-top: clamp(22px, 3vw, 32px);
}

.page-about .line-card {
  background: var(--panel);
  border-top: 4px solid var(--cyan);
  padding: clamp(18px, 2.6vw, 26px);
}

.page-about .line-card--ticket {
  border-top-color: var(--orange);
}

.page-about .line-card h3 {
  margin: 10px 0 12px;
  font-family: var(--font-display);
  font-weight: 800;
  font-size: var(--fs-md);
  line-height: 1.3;
  color: var(--white);
}

.page-about .line-card p {
  margin: 0 0 12px;
  font-size: var(--fs-sm);
  line-height: 1.75;
  color: var(--muted);
}

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

.page-about .inline-link {
  color: var(--cyan);
  text-decoration: none;
  border-bottom: 2px solid rgba(0, 229, 208, 0.4);
  padding-bottom: 1px;
  transition: border-color 180ms var(--ease), color 180ms var(--ease);
}

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

.page-about .inline-link--hot {
  color: var(--orange-soft);
  border-bottom-color: rgba(255, 106, 26, 0.45);
}

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

/* ---------- 团队分工 ---------- */
.page-about .role-grid {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 2px;
  background: var(--steel);
  border: var(--about-rule);
  margin-top: clamp(20px, 3vw, 30px);
}

.page-about .role {
  background: var(--deep);
  padding: clamp(16px, 2.2vw, 24px);
}

.page-about .role-num {
  display: block;
  margin: 0 0 10px;
  font-family: var(--font-mono);
  font-size: clamp(32px, 4.2vw, 46px);
  font-weight: 700;
  line-height: 1;
  letter-spacing: -0.02em;
  color: var(--cyan);
  font-variant-numeric: tabular-nums;
}

.page-about .role h3 {
  margin: 0 0 10px;
  font-family: var(--font-display);
  font-weight: 800;
  font-size: var(--fs-base);
  color: var(--white);
}

.page-about .role p:last-child {
  margin: 0;
  font-size: var(--fs-sm);
  line-height: 1.7;
  color: var(--muted);
}

.page-about .cycle-caption {
  margin: clamp(26px, 3.6vw, 38px) 0 14px !important;
  font-family: var(--font-mono);
  font-size: var(--fs-xs);
  letter-spacing: 0.18em;
  text-transform: uppercase;
  color: var(--muted) !important;
}

.page-about .cycle {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 16px;
  list-style: none;
  margin: 0;
  padding: 0;
}

.page-about .cycle-item {
  border-left: 2px solid var(--steel);
  padding-left: 14px;
}

.page-about .cycle-time {
  margin: 0 0 6px;
  font-family: var(--font-mono);
  font-size: var(--fs-xs);
  letter-spacing: 0.1em;
  color: var(--orange);
  font-variant-numeric: tabular-nums;
}

.page-about .cycle-title {
  margin: 0 0 12px;
  font-size: var(--fs-base);
  color: var(--white);
}

.page-about .cycle-bar {
  display: block;
  background: var(--cyan);
}

.page-about .cycle-bar--1 {
  width: 32%;
  height: 9px;
}

.page-about .cycle-bar--2 {
  width: 62%;
  height: 5px;
}

.page-about .cycle-bar--3 {
  width: 100%;
  height: 3px;
}

/* ---------- 数据核对 ---------- */
.page-about .workbench {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: clamp(20px, 3vw, 30px);
  align-items: start;
}

.page-about .workbench-text {
  min-width: 0;
}

.page-about .workbench-text > p {
  margin: 0 0 1.15em;
  font-size: var(--fs-base);
  line-height: 1.75;
  color: var(--muted);
}

.page-about .steps {
  list-style: none;
  margin: 0 0 1.3em;
  padding: 0;
  display: grid;
  gap: 2px;
  background: var(--steel);
  border: var(--about-rule);
}

.page-about .steps li {
  background: var(--panel);
  padding: 14px 16px 16px;
}

.page-about .steps h3 {
  margin: 4px 0 6px;
  font-family: var(--font-display);
  font-weight: 800;
  font-size: var(--fs-base);
  color: var(--white);
}

.page-about .steps p {
  margin: 0;
  font-size: var(--fs-sm);
  line-height: 1.7;
  color: var(--muted);
}

.page-about .step-no {
  font-family: var(--font-mono);
  font-size: var(--fs-xs);
  letter-spacing: 0.14em;
  color: var(--cyan);
}

.page-about .scope-note {
  border: var(--about-rule);
  background: var(--panel);
  margin-top: 6px;
}

.page-about .scope-note summary {
  cursor: pointer;
  padding: 12px 16px;
  font-family: var(--font-mono);
  font-size: var(--fs-sm);
  letter-spacing: 0.04em;
  color: var(--cyan);
  list-style-position: inside;
}

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

.page-about .scope-note[open] summary {
  border-bottom: var(--about-rule);
  color: var(--cyan-soft);
}

.page-about .scope-note p {
  margin: 0;
  padding: 14px 16px 18px;
  font-size: var(--fs-sm);
  line-height: 1.75;
  color: var(--muted);
}

/* ---------- 里程碑 ---------- */
.page-about .timeline-plate {
  margin: clamp(18px, 2.6vw, 28px) 0 clamp(22px, 3vw, 32px);
}

.page-about .timeline-scroll {
  overflow-x: auto;
  overflow-y: hidden;
  padding-bottom: 14px;
  border-bottom: 2px solid var(--steel);
  scrollbar-width: thin;
  scroll-snap-type: x proximity;
  max-width: 100%;
}

.page-about .timeline-scroll:focus-visible {
  outline: 2px solid var(--cyan);
  outline-offset: 4px;
}

.page-about .timeline {
  display: flex;
  list-style: none;
  margin: 0;
  padding: 0;
  min-width: 760px;
}

.page-about .tl-node {
  position: relative;
  flex: 1 0 210px;
  padding: 34px 20px 6px 0;
  border-top: 2px solid var(--steel);
  scroll-snap-align: start;
}

.page-about .tl-node::before {
  content: "";
  position: absolute;
  top: -8px;
  left: 0;
  width: 13px;
  height: 13px;
  border-radius: 50%;
  background: var(--muted);
  border: 2px solid var(--ink);
}

.page-about .tl-node--current::before {
  background: var(--cyan);
}

.page-about .tl-era {
  margin: 0 0 8px;
  font-family: var(--font-mono);
  font-size: var(--fs-xs);
  letter-spacing: 0.14em;
  color: var(--orange);
}

.page-about .tl-node--current .tl-era {
  color: var(--cyan);
}

.page-about .tl-node h3 {
  margin: 0 0 8px;
  font-family: var(--font-display);
  font-weight: 800;
  font-size: var(--fs-base);
  line-height: 1.35;
  color: var(--white);
}

.page-about .tl-node p {
  margin: 0;
  font-size: var(--fs-sm);
  line-height: 1.7;
  color: var(--muted);
}

/* ---------- 合作与边界 ---------- */
.page-about .partner-list {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 2px;
  background: var(--steel);
  border: var(--about-rule);
  list-style: none;
  margin: clamp(20px, 3vw, 30px) 0 clamp(22px, 3vw, 30px);
  padding: 0;
}

.page-about .partner-list li {
  background: var(--panel);
  padding: 16px 18px 18px;
}

.page-about .pnum {
  display: block;
  font-family: var(--font-mono);
  font-size: clamp(28px, 3.6vw, 40px);
  font-weight: 700;
  line-height: 1;
  color: var(--cyan);
  font-variant-numeric: tabular-nums;
}

.page-about .plabel {
  display: block;
  margin: 10px 0 8px;
  font-family: var(--font-display);
  font-weight: 800;
  font-size: var(--fs-base);
  color: var(--white);
}

.page-about .pnote {
  display: block;
  font-size: var(--fs-sm);
  line-height: 1.7;
  color: var(--muted);
}

.page-about .boundary {
  border: var(--about-rule);
  border-left: 4px solid var(--orange);
  background: rgba(255, 106, 26, 0.07);
  padding: 18px 18px 20px;
}

.page-about .boundary-tag {
  margin: 0 0 10px;
  font-family: var(--font-mono);
  font-size: var(--fs-xs);
  letter-spacing: 0.2em;
  color: var(--orange);
}

.page-about .boundary p:last-child {
  margin: 0;
  font-size: var(--fs-sm);
  line-height: 1.75;
  color: var(--white);
}

/* ---------- 备案与联络 ---------- */
.page-about .archive {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 2px;
  background: var(--steel);
  border: var(--about-rule);
  margin-top: clamp(18px, 2.6vw, 28px);
}

.page-about .archive-block {
  background: var(--deep);
  padding: 18px 18px 20px;
}

.page-about .archive-value {
  margin: 8px 0 10px;
  font-family: var(--font-mono);
  font-size: var(--fs-base);
  line-height: 1.5;
  letter-spacing: 0.01em;
  color: var(--white);
  word-break: break-word;
}

.page-about .archive-note {
  margin: 0;
  font-size: var(--fs-sm);
  line-height: 1.7;
  color: var(--muted);
}

.page-about .filing {
  margin: 18px 0 0 !important;
  font-family: var(--font-mono);
  font-size: var(--fs-sm);
  letter-spacing: 0.04em;
  color: var(--muted) !important;
}

/* ---------- 焦点可见性 ---------- */
.page-about a:focus-visible,
.page-about summary:focus-visible,
.page-about .timeline-scroll:focus-visible {
  outline: 2px solid var(--cyan);
  outline-offset: 3px;
}

/* ---------- 响应式 ---------- */
@media (min-width: 640px) {
  .page-about .principles {
    grid-template-columns: repeat(3, minmax(0, 1fr));
    gap: 16px;
  }

  .page-about .cycle {
    grid-template-columns: repeat(3, minmax(0, 1fr));
    gap: 18px;
  }

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

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

@media (min-width: 800px) {
  .page-about .about-facts {
    grid-template-columns: repeat(4, minmax(0, 1fr));
  }

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

  .page-about .twin-line {
    grid-template-columns: 58fr 42fr;
  }
}

@media (min-width: 880px) {
  .page-about .workbench {
    grid-template-columns: minmax(0, 1fr) minmax(0, 1fr);
    gap: clamp(22px, 2.8vw, 34px);
  }
}

@media (min-width: 960px) {
  .page-about .chapter-layout {
    grid-template-columns: var(--about-index-w) minmax(0, 1fr);
    gap: clamp(32px, 4vw, 68px);
  }

  .page-about .chapter-index {
    position: sticky;
    top: 96px;
    border-bottom: 0;
    padding-bottom: 0;
  }

  .page-about .chapter-index-list {
    flex-direction: column;
    gap: 2px;
    overflow: visible;
    padding: 0;
  }

  .page-about .chapter-index-list a {
    white-space: normal;
    padding: 7px 10px 7px 0;
  }
}

@media (max-width: 400px) {
  .page-about .about-facts {
    grid-template-columns: minmax(0, 1fr);
  }
}
<<<END>>>