.page-about {
  --about-rail: 6.5rem;
  --about-soft: rgba(244, 239, 227, 0.76);
  --about-line: rgba(201, 164, 92, 0.34);
  background: var(--ink);
  color: var(--paper);
  overflow-x: hidden;
}

.page-about .about-crumb-bar {
  padding-block: 1rem 0.35rem;
}

.page-about .breadcrumb ol {
  display: flex;
  flex-wrap: wrap;
  gap: 0.5rem;
  align-items: center;
  margin: 0;
  padding: 0;
  list-style: none;
  font-family: var(--font-mono);
  font-size: 0.72rem;
  letter-spacing: 0.06em;
  color: var(--moss);
}

.page-about .breadcrumb li + li::before {
  content: "/";
  margin-right: 0.5rem;
  color: var(--gold-deep);
}

.page-about .breadcrumb a {
  color: var(--moss);
  text-decoration: none;
  border-bottom: 1px solid transparent;
}

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

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

/* ---------- 首屏主题声明 ---------- */
.page-about .about-masthead {
  position: relative;
  padding-block: 2rem 2.5rem;
  border-bottom: var(--frame) solid var(--line);
  background:
    radial-gradient(120% 100% at 6% 0%, rgba(61, 224, 208, 0.16), transparent 58%),
    radial-gradient(90% 80% at 96% 12%, rgba(201, 164, 92, 0.18), transparent 60%),
    linear-gradient(158deg, var(--ink-2) 0%, var(--ink) 60%, var(--ink-3) 100%);
}

.page-about .about-masthead-inner {
  display: grid;
  gap: 1.75rem;
  min-width: 0;
}

.page-about .kicker {
  margin: 0 0 0.9rem;
  padding-top: 0.7rem;
  border-top: 1px solid var(--about-line);
  font-family: var(--font-mono);
  font-size: 0.72rem;
  letter-spacing: 0.16em;
  color: var(--gold);
}

.page-about h1 {
  margin: 0;
  font-family: var(--font-head);
  font-weight: 800;
  font-size: clamp(1.85rem, 7.4vw, 3.4rem);
  line-height: 1.1;
  letter-spacing: -0.01em;
  color: var(--paper);
  text-wrap: balance;
}

.page-about .lede {
  margin: 1.05rem 0 0;
  max-width: 46ch;
  font-size: 1rem;
  line-height: 1.8;
  color: var(--about-soft);
}

.page-about .about-masthead-cta {
  display: flex;
  flex-wrap: wrap;
  gap: 0.65rem;
  margin: 1.5rem 0 0;
}

.page-about .about-masthead-side {
  border: 2px solid var(--line);
  background: rgba(7, 30, 26, 0.62);
  box-shadow: var(--shadow-deep);
  padding: 1rem 1rem 1.15rem;
}

.page-about .about-side-title {
  margin: 0 0 0.75rem;
  font-family: var(--font-mono);
  font-size: 0.7rem;
  letter-spacing: 0.18em;
  color: var(--cyan);
}

.page-about .about-facts {
  display: grid;
  gap: 0.85rem;
  margin: 0;
  padding: 0;
  list-style: none;
}

.page-about .about-facts li {
  display: grid;
  gap: 0.15rem;
  padding-left: 0.65rem;
  border-left: 2px solid var(--gold-deep);
}

.page-about .about-fact-num {
  font-family: var(--font-head);
  font-weight: 800;
  font-size: 1.45rem;
  line-height: 1.1;
  color: var(--gold);
}

.page-about .about-fact-label {
  font-family: var(--font-mono);
  font-size: 0.72rem;
  letter-spacing: 0.04em;
  color: var(--moss);
}

/* ---------- 目录索引带 ---------- */
.page-about .about-index-band {
  background: var(--ink-2);
  border-bottom: 2px solid var(--line);
}

.page-about .about-index-list {
  display: flex;
  margin: 0;
  padding: 0;
  list-style: none;
  overflow-x: auto;
  scrollbar-width: thin;
  -webkit-overflow-scrolling: touch;
}

.page-about .about-index-list li {
  flex: 1 0 auto;
  border-right: 1px solid rgba(16, 23, 20, 0.6);
}

.page-about .about-index-list li:last-child {
  border-right: 0;
}

.page-about .about-index-list a {
  display: flex;
  align-items: baseline;
  gap: 0.5rem;
  padding: 0.85rem 0.95rem;
  font-family: var(--font-mono);
  font-size: 0.78rem;
  letter-spacing: 0.04em;
  color: var(--paper);
  text-decoration: none;
  white-space: nowrap;
}

.page-about .about-idx-num {
  font-size: 0.66rem;
  color: var(--gold);
}

.page-about .about-index-list a:hover,
.page-about .about-index-list a:focus-visible {
  background: var(--ink-3);
  color: var(--cyan);
}

/* ---------- 主体双栏 ---------- */
.page-about .about-layout {
  display: grid;
  gap: 2rem;
  padding-block: 2.25rem 3rem;
  min-width: 0;
}

.page-about .about-rail {
  display: none;
}

.page-about .about-rail-list {
  display: grid;
  gap: 0.85rem;
  margin: 0;
  padding: 0;
  list-style: none;
}

.page-about .about-rail-list li {
  display: grid;
  gap: 0.1rem;
  padding-left: 0.6rem;
  border-left: 2px solid var(--gold-deep);
}

.page-about .about-rail-num {
  font-family: var(--font-mono);
  font-size: 0.66rem;
  color: var(--gold);
}

.page-about .about-rail-list a {
  font-family: var(--font-mono);
  font-size: 0.78rem;
  line-height: 1.4;
  color: var(--about-soft);
  text-decoration: none;
}

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

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

.page-about .about-section + .about-section {
  margin-top: 2.75rem;
}

.page-about .about-section-head {
  display: flex;
  align-items: flex-start;
  gap: 0.8rem;
  padding-top: 0.85rem;
  border-top: 1px solid var(--about-line);
}

.page-about .about-sec-num {
  flex: 0 0 auto;
  padding: 0.16rem 0.4rem;
  border: 1px solid var(--gold-deep);
  font-family: var(--font-mono);
  font-size: 0.72rem;
  color: var(--gold);
}

.page-about .about-h2 {
  margin: 0;
  font-family: var(--font-head);
  font-weight: 800;
  font-size: clamp(1.3rem, 4.6vw, 2rem);
  line-height: 1.24;
  color: var(--paper);
  text-wrap: balance;
}

.page-about .about-h2 ~ * {
  margin-top: 0.95rem;
}

.page-about .about-prose {
  max-width: 62ch;
  margin: 0.95rem 0 0;
  font-size: 0.97rem;
  line-height: 1.82;
  color: var(--about-soft);
}

.page-about .about-prose a,
.page-about .about-fold-body a,
.page-about .about-next-note a {
  color: var(--cyan);
  text-decoration: none;
  border-bottom: 1px solid rgba(61, 224, 208, 0.5);
}

.page-about .about-prose a:hover,
.page-about .about-fold-body a:hover,
.page-about .about-next-note a:hover,
.page-about .about-prose a:focus-visible,
.page-about .about-fold-body a:focus-visible,
.page-about .about-next-note a:focus-visible {
  color: var(--paper);
  border-bottom-color: var(--paper);
}

/* ---------- 数据条 ---------- */
.page-about .about-metrics {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 0.6rem;
  margin: 1.35rem 0 0;
  padding: 0;
  list-style: none;
}

.page-about .about-metrics li {
  display: grid;
  gap: 0.1rem;
  padding: 0.8rem 0.85rem;
  border: 2px solid var(--line);
  background: var(--ink-2);
  box-shadow: var(--shadow-deep);
}

.page-about .about-metric-num {
  font-family: var(--font-head);
  font-weight: 800;
  font-size: 1.75rem;
  line-height: 1.05;
  color: var(--gold);
}

.page-about .about-metric-label {
  font-family: var(--font-mono);
  font-size: 0.7rem;
  letter-spacing: 0.05em;
  color: var(--moss);
}

/* ---------- 折叠组 ---------- */
.page-about .about-tree,
.page-about .about-roles {
  display: grid;
  gap: 0.55rem;
  margin: 1.35rem 0 0;
}

.page-about .about-fold {
  border: 2px solid var(--line);
  background: var(--ink-2);
  box-shadow: 4px 4px 0 rgba(16, 23, 20, 0.5);
}

.page-about .about-fold > summary {
  display: flex;
  align-items: baseline;
  gap: 0.6rem;
  padding: 0.75rem 0.85rem;
  cursor: pointer;
  list-style: none;
  font-family: var(--font-mono);
  font-size: 0.85rem;
  letter-spacing: 0.03em;
  color: var(--paper);
}

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

.page-about .about-fold > summary::after {
  content: "+";
  margin-left: auto;
  font-size: 1.05rem;
  line-height: 1;
  color: var(--cyan);
}

.page-about .about-fold[open] > summary::after {
  content: "−";
}

.page-about .about-fold[open] > summary {
  border-bottom: 1px solid rgba(201, 164, 92, 0.32);
  color: var(--cyan);
}

.page-about .about-fold > summary:hover,
.page-about .about-fold > summary:focus-visible {
  color: var(--cyan);
  outline: none;
}

.page-about .about-fold-code {
  flex: 0 0 auto;
  font-size: 0.66rem;
  letter-spacing: 0.08em;
  color: var(--gold);
}

.page-about .about-fold-body {
  padding: 0.8rem 0.9rem 0.95rem;
  font-size: 0.9rem;
  line-height: 1.78;
  color: var(--about-soft);
}

.page-about .about-fold-body p {
  margin: 0;
}

.page-about .about-fold-body ul {
  margin: 0.6rem 0 0;
  padding-left: 1.05rem;
  font-family: var(--font-mono);
  font-size: 0.78rem;
  color: var(--gold);
}

.page-about .about-fold-body li + li {
  margin-top: 0.25rem;
}

/* ---------- 图 ---------- */
.page-about .about-figure {
  margin: 1.6rem 0 0;
}

.page-about .about-figure .media-frame {
  border: 2px solid var(--line);
  box-shadow: var(--shadow-hard);
  background: linear-gradient(150deg, rgba(61, 224, 208, 0.18), rgba(201, 164, 92, 0.22) 55%, rgba(240, 138, 60, 0.16));
  overflow: hidden;
}

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

.page-about .about-figure figcaption {
  margin-top: 0.55rem;
  font-family: var(--font-mono);
  font-size: 0.72rem;
  line-height: 1.65;
  color: var(--moss);
}

/* ---------- 浅色分区：服务与节奏 ---------- */
.page-about .about-section--panel {
  padding: 1.35rem 1.1rem 1.6rem;
  border: 2px solid var(--line);
  background: var(--mint);
  box-shadow: var(--shadow-hard);
  color: var(--ink);
}

.page-about .about-section--panel .about-section-head {
  border-top-color: rgba(16, 23, 20, 0.35);
}

.page-about .about-section--panel .about-sec-num {
  border-color: var(--gold-deep);
  color: var(--gold-deep);
}

.page-about .about-section--panel .about-h2 {
  color: var(--ink);
}

.page-about .about-section--panel .about-prose {
  color: #1b3a33;
}

.page-about .about-cadence {
  display: grid;
  gap: 0.6rem;
  margin: 1.35rem 0 0;
  padding: 0;
  list-style: none;
}

.page-about .about-cadence li {
  display: grid;
  gap: 0.25rem;
  padding: 0.8rem 0.85rem;
  border: 2px solid var(--line);
  background: var(--paper);
  box-shadow: 4px 4px 0 rgba(16, 23, 20, 0.28);
}

.page-about .about-cad-num {
  font-family: var(--font-mono);
  font-size: 0.68rem;
  letter-spacing: 0.08em;
  color: var(--gold-deep);
}

.page-about .about-cadence strong {
  font-family: var(--font-head);
  font-size: 1.02rem;
  color: var(--ink);
}

.page-about .about-cadence span:last-child {
  font-size: 0.86rem;
  line-height: 1.7;
  color: #274840;
}

/* ---------- 时间轴 ---------- */
.page-about .about-timeline {
  margin: 1.5rem 0 0;
  padding: 0 0 0 0.9rem;
  list-style: none;
}

.page-about .about-tl-item {
  position: relative;
  padding: 0 0 1.5rem 1.5rem;
  border-left: 4px solid var(--gold-deep);
}

.page-about .about-tl-item:last-child {
  padding-bottom: 0;
  border-left-color: transparent;
}

.page-about .about-tl-node {
  position: absolute;
  left: -1rem;
  top: 0;
  display: grid;
  place-items: center;
  width: 1.6rem;
  height: 1.6rem;
  border: 2px solid var(--gold);
  border-radius: 50%;
  background: var(--ink-3);
  font-family: var(--font-mono);
  font-size: 0.62rem;
  color: var(--gold);
}

.page-about .about-tl-body h3 {
  margin: 0;
  font-family: var(--font-head);
  font-weight: 800;
  font-size: 1.06rem;
  line-height: 1.4;
  color: var(--paper);
}

.page-about .about-tl-body p {
  margin: 0.45rem 0 0;
  font-size: 0.93rem;
  line-height: 1.78;
  color: var(--about-soft);
}

.page-about .about-tl-body .about-fold {
  margin-top: 0.7rem;
}

/* ---------- 结尾导流 ---------- */
.page-about .about-next {
  border-top: var(--frame) solid var(--line);
  background: linear-gradient(180deg, var(--ink-3) 0%, var(--ink-2) 100%);
  padding-block: 2.25rem 2.75rem;
}

.page-about .about-next-title {
  margin: 0;
  font-family: var(--font-head);
  font-weight: 800;
  font-size: clamp(1.2rem, 4.4vw, 1.7rem);
  line-height: 1.3;
  color: var(--paper);
}

.page-about .about-next-list {
  display: grid;
  gap: 0.7rem;
  margin: 1.3rem 0 0;
  padding: 0;
  list-style: none;
}

.page-about .about-next-list a {
  display: grid;
  gap: 0.25rem;
  height: 100%;
  padding: 1rem 1.05rem;
  border: 2px solid var(--line);
  background: var(--ink);
  box-shadow: var(--shadow-deep);
  text-decoration: none;
  transition: transform 0.18s var(--ease), box-shadow 0.18s var(--ease);
}

.page-about .about-next-list a:hover,
.page-about .about-next-list a:focus-visible {
  transform: translate(-2px, -2px);
  box-shadow: var(--shadow-hard);
}

.page-about .about-next-num {
  font-family: var(--font-mono);
  font-size: 0.7rem;
  letter-spacing: 0.12em;
  color: var(--gold);
}

.page-about .about-next-list strong {
  font-family: var(--font-head);
  font-size: 1.05rem;
  color: var(--paper);
}

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

.page-about .about-next-list a > span:last-child {
  font-size: 0.86rem;
  line-height: 1.7;
  color: var(--about-soft);
}

.page-about .about-next-note {
  margin: 1.3rem 0 0;
  font-size: 0.88rem;
  line-height: 1.8;
  color: var(--moss);
}

/* ---------- 断点 ---------- */
@media (min-width: 40rem) {
  .page-about .about-masthead {
    padding-block: 2.5rem 3rem;
  }

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

  .page-about .about-metrics {
    grid-template-columns: repeat(4, minmax(0, 1fr));
  }

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

  .page-about .about-section--panel {
    padding: 1.6rem 1.5rem 1.9rem;
  }
}

@media (min-width: 60rem) {
  .page-about .about-masthead-inner {
    grid-template-columns: minmax(0, 1.5fr) minmax(0, 0.62fr);
    gap: 2.5rem;
    align-items: start;
  }

  .page-about .about-masthead-side {
    margin-top: 0.4rem;
  }

  .page-about .about-layout {
    grid-template-columns: var(--about-rail) minmax(0, 1fr);
    gap: 2.75rem;
    padding-block: 3rem 3.75rem;
  }

  .page-about .about-rail {
    display: block;
    position: sticky;
    top: 5.5rem;
    align-self: start;
  }

  .page-about .about-section + .about-section {
    margin-top: 3.5rem;
  }

  .page-about .about-section--panel {
    padding: 1.9rem 2rem 2.2rem;
  }

  .page-about .about-timeline {
    padding-left: 1.1rem;
  }
}
<<<END>>>