.page-about {
  background: var(--ink-night);
  color: var(--paper);
  font-family: var(--font-sans);
  font-size: 16px;
  line-height: 1.75;
  overflow-x: hidden;
}

.page-about p {
  margin: 0 0 14px;
}

.page-about a {
  color: var(--grass-soft);
}

/* ===== 首屏 ===== */
.page-about .about-hero {
  position: relative;
  padding: clamp(24px, 5vw, 56px) 0 clamp(30px, 5vw, 54px);
  background:
    radial-gradient(120% 90% at 6% 0%, rgba(124, 255, 107, 0.10), transparent 58%),
    repeating-linear-gradient(90deg, rgba(27, 53, 80, 0.5) 0 1px, transparent 1px 72px),
    repeating-linear-gradient(0deg, rgba(27, 53, 80, 0.3) 0 1px, transparent 1px 72px),
    var(--ink-night);
  border-bottom: var(--hair);
}

.page-about .crumbs ol {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
  list-style: none;
  margin: 0 0 22px;
  padding: 0;
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.06em;
  color: var(--mist);
}

.page-about .crumbs li:not(:last-child)::after {
  content: "/";
  margin-left: 8px;
  color: var(--line-blue);
}

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

.page-about .crumbs a:hover,
.page-about .crumbs a:focus-visible {
  color: var(--grass);
}

.page-about .hero-coord {
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: 0.18em;
  color: var(--grass);
  margin: 0 0 10px;
}

.page-about .about-hero h1 {
  font-family: var(--font-serif);
  font-weight: 800;
  font-size: clamp(30px, 7.4vw, 56px);
  line-height: 1.16;
  letter-spacing: -0.01em;
  margin: 0 0 16px;
  max-width: 18ch;
  color: var(--paper);
}

.page-about .hero-lead {
  color: var(--mist);
  font-size: clamp(15px, 2.4vw, 17px);
  max-width: 64ch;
  margin: 0;
}

.page-about .hero-stats {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 1px;
  margin-top: 26px;
  background: var(--line-blue);
  border: 1px solid var(--line-blue);
}

.page-about .hero-stat {
  background: rgba(18, 38, 61, 0.94);
  padding: 14px 16px;
}

.page-about .stat-num {
  display: block;
  font-family: var(--font-mono);
  font-size: clamp(22px, 4vw, 30px);
  line-height: 1.1;
  color: var(--paper);
}

.page-about .stat-label {
  display: block;
  margin-top: 5px;
  font-size: 12px;
  letter-spacing: 0.06em;
  color: var(--mist);
}

/* ===== 双栏骨架 ===== */
.page-about .about-body {
  padding-block: clamp(28px, 4vw, 56px) clamp(44px, 6vw, 84px);
}

.page-about .index-rail {
  border: 1px solid var(--line-blue);
  background: var(--panel);
  padding: 14px 14px 12px;
  margin-bottom: clamp(24px, 4vw, 40px);
}

.page-about .rail-title {
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: 0.16em;
  color: var(--grass);
  margin: 0 0 10px;
}

.page-about .rail-list {
  list-style: none;
  margin: 0;
  padding: 0;
  display: flex;
  gap: 8px;
  overflow-x: auto;
}

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

.page-about .rail-list a {
  display: inline-block;
  padding: 7px 11px;
  border: 1px solid var(--line-blue);
  font-size: 13px;
  color: var(--mist);
  text-decoration: none;
  white-space: nowrap;
  transition: background 0.2s var(--ease), color 0.2s var(--ease);
}

.page-about .rail-list a:hover,
.page-about .rail-list a:focus-visible {
  color: var(--ink-night);
  background: var(--grass);
  border-color: var(--grass);
}

/* ===== 章节通用 ===== */
.page-about .story-section {
  padding-bottom: clamp(28px, 4vw, 50px);
  margin-bottom: clamp(28px, 4vw, 50px);
  border-bottom: 1px solid var(--line-blue);
  scroll-margin-top: calc(var(--header-h) + 20px);
}

.page-about .story-section:last-of-type {
  border-bottom: 0;
}

.page-about .sec-head {
  display: flex;
  flex-wrap: wrap;
  align-items: baseline;
  gap: 8px 12px;
  margin-bottom: 12px;
}

.page-about .sec-num {
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.16em;
  color: var(--grass);
}

.page-about .sec-title {
  font-family: var(--font-serif);
  font-weight: 800;
  font-size: clamp(21px, 3.6vw, 31px);
  line-height: 1.3;
  margin: 0;
  color: var(--paper);
}

.page-about .sec-lead {
  color: var(--mist);
  font-size: 15px;
  max-width: 62ch;
}

/* ===== 图片 ===== */
.page-about .media-frame {
  margin: 18px 0 22px;
  border: 1px solid var(--line-blue);
  background: var(--panel);
  overflow: hidden;
}

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

.page-about .media-caption {
  padding: 9px 12px;
  border-top: 1px solid var(--line-blue);
  background: rgba(14, 27, 44, 0.62);
  font-size: 12.5px;
  color: var(--mist);
}

/* ===== 时间线 ===== */
.page-about .timeline {
  list-style: none;
  position: relative;
  margin: 22px 0 0;
  padding: 0 0 0 26px;
}

.page-about .timeline::before {
  content: "";
  position: absolute;
  left: 7px;
  top: 12px;
  bottom: 12px;
  width: 1px;
  background: linear-gradient(180deg, var(--grass), var(--line-blue) 78%);
}

.page-about .tl-item {
  position: relative;
}

.page-about .tl-item::before {
  content: "";
  position: absolute;
  left: -23px;
  top: 19px;
  width: 9px;
  height: 9px;
  border-radius: 50%;
  background: var(--ink-night);
  border: 1px solid var(--grass);
  box-shadow: 0 0 0 3px rgba(124, 255, 107, 0.10);
}

.page-about .tl-item details {
  border-bottom: 1px solid rgba(27, 53, 80, 0.85);
}

.page-about .tl-item summary {
  list-style: none;
  cursor: pointer;
  display: flex;
  flex-wrap: wrap;
  align-items: baseline;
  gap: 8px 10px;
  padding: 10px 0;
}

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

.page-about .tl-item summary:focus-visible {
  outline: 2px solid var(--grass);
  outline-offset: 2px;
}

.page-about .tl-item summary::after {
  content: "+";
  margin-left: auto;
  font-family: var(--font-mono);
  font-size: 16px;
  line-height: 1;
  color: var(--grass);
}

.page-about .tl-item details[open] summary::after {
  content: "–";
}

.page-about .tl-phase {
  font-family: var(--font-mono);
  font-size: 12px;
  color: var(--grass);
  letter-spacing: 0.05em;
}

.page-about .tl-title {
  font-family: var(--font-serif);
  font-weight: 700;
  font-size: clamp(17px, 2.6vw, 20px);
  color: var(--paper);
}

.page-about .tl-body {
  padding: 0 0 14px;
  color: var(--mist);
  font-size: 15px;
}

/* ===== 协作桌 ===== */
.page-about .desk-grid {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 12px;
  margin-top: 20px;
}

.page-about .desk-cell {
  position: relative;
  border: 1px solid var(--line-blue);
  background: var(--panel);
  padding: 16px 16px 14px;
}

.page-about .desk-cell::before {
  content: attr(data-coord);
  position: absolute;
  top: 9px;
  right: 12px;
  font-family: var(--font-mono);
  font-size: 10px;
  letter-spacing: 0.14em;
  color: rgba(201, 212, 224, 0.4);
}

.page-about .desk-meta {
  display: block;
  margin-bottom: 6px;
  font-family: var(--font-mono);
  font-size: 11.5px;
  letter-spacing: 0.08em;
  color: var(--grass-soft);
}

.page-about .desk-name {
  font-family: var(--font-serif);
  font-size: 17px;
  font-weight: 700;
  margin: 0 0 6px;
  color: var(--paper);
}

.page-about .desk-cell p {
  margin: 0;
  font-size: 14.5px;
  color: var(--mist);
}

.page-about .desk-photo {
  margin-top: 20px;
}

.page-about .flow {
  list-style: none;
  margin: 18px 0 0;
  padding: 0;
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 8px;
}

.page-about .flow li {
  border: 1px solid var(--line-blue);
  background: rgba(18, 38, 61, 0.72);
  padding: 12px 14px;
}

.page-about .flow-step {
  display: block;
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: 0.12em;
  color: var(--grass);
  margin-bottom: 4px;
}

.page-about .flow-label {
  display: block;
  font-size: 14.5px;
  font-weight: 600;
  color: var(--paper);
}

.page-about .flow-note {
  display: block;
  margin-top: 2px;
  font-size: 13px;
  color: var(--mist);
}

/* ===== 四级路径 ===== */
.page-about .path-list {
  list-style: none;
  margin: 20px 0 0;
  padding: 0;
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 12px;
}

.page-about .path-item {
  display: grid;
  grid-template-columns: 42px minmax(0, 1fr);
  gap: 12px;
  border: 1px solid var(--line-blue);
  background: var(--panel);
  padding: 14px 16px;
}

.page-about .path-idx {
  font-family: var(--font-mono);
  font-size: 22px;
  line-height: 1;
  color: var(--grass);
}

.page-about .path-title {
  font-family: var(--font-serif);
  font-size: 17px;
  font-weight: 700;
  margin: 0 0 4px;
  color: var(--paper);
}

.page-about .path-body p {
  margin: 0;
  font-size: 14.5px;
  color: var(--mist);
}

.page-about .path-link {
  display: inline-block;
  margin-top: 8px;
  font-family: var(--font-mono);
  font-size: 13px;
  color: var(--grass);
  text-decoration: none;
  border-bottom: 1px solid rgba(124, 255, 107, 0.45);
}

.page-about .path-link:hover,
.page-about .path-link:focus-visible {
  color: var(--grass-soft);
}

/* ===== 城市网络 ===== */
.page-about .net-wrap {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 20px;
  margin-top: 20px;
}

.page-about .net-wrap .media-frame {
  margin: 0;
}

.page-about .net-figures {
  list-style: none;
  margin: 0 0 18px;
  padding: 0;
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 10px 14px;
}

.page-about .net-figures li {
  border-left: 2px solid var(--grass);
  padding: 5px 0 5px 11px;
}

.page-about .net-num {
  display: block;
  font-family: var(--font-mono);
  font-size: 21px;
  line-height: 1.1;
  color: var(--paper);
}

.page-about .net-label {
  display: block;
  margin-top: 3px;
  font-size: 12.5px;
  color: var(--mist);
}

.page-about .net-nodes {
  list-style: none;
  margin: 0 0 18px;
  padding: 0;
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 8px;
}

.page-about .net-node {
  position: relative;
  border: 1px solid var(--line-blue);
  background: rgba(18, 38, 61, 0.72);
  padding: 10px 12px 10px 30px;
  transition: border-color 0.2s var(--ease), background 0.2s var(--ease);
}

.page-about .net-node::before {
  content: "";
  position: absolute;
  left: 12px;
  top: 18px;
  width: 7px;
  height: 7px;
  border-radius: 50%;
  background: var(--grass);
  box-shadow: 0 0 0 3px rgba(124, 255, 107, 0.12);
}

.page-about .net-node:hover,
.page-about .net-node:focus-visible {
  border-color: var(--grass);
  background: rgba(124, 255, 107, 0.07);
  outline: none;
}

.page-about .node-name {
  display: block;
  font-size: 14.5px;
  font-weight: 600;
  color: var(--paper);
}

.page-about .node-tip {
  display: block;
  margin-top: 2px;
  font-size: 13px;
  color: var(--mist);
}

.page-about .net-service {
  border: 1px solid var(--line-blue);
  border-top: 2px solid var(--wine);
  background: var(--panel);
  padding: 16px;
}

.page-about .net-service-title {
  font-family: var(--font-serif);
  font-size: 16px;
  font-weight: 700;
  margin: 0 0 10px;
  color: var(--paper);
}

.page-about .service-list {
  list-style: none;
  margin: 0 0 14px;
  padding: 0;
  display: grid;
  gap: 7px;
  counter-reset: svc;
}

.page-about .service-list li {
  position: relative;
  padding-left: 24px;
  font-size: 14px;
  color: var(--mist);
  counter-increment: svc;
}

.page-about .service-list li::before {
  content: counter(svc, decimal-leading-zero);
  position: absolute;
  left: 0;
  top: 2px;
  font-family: var(--font-mono);
  font-size: 11px;
  color: var(--grass);
}

/* ===== 季度节奏 ===== */
.page-about .cadence {
  list-style: none;
  margin: 20px 0 0;
  padding: 0;
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 12px;
}

.page-about .cadence li {
  border: 1px solid var(--line-blue);
  border-top: 2px solid var(--wine);
  background: var(--panel);
  padding: 14px 16px;
}

.page-about .cadence-k {
  display: block;
  margin-bottom: 6px;
  font-family: var(--font-mono);
  font-size: 11.5px;
  letter-spacing: 0.14em;
  color: var(--grass);
}

.page-about .cadence-title {
  font-family: var(--font-serif);
  font-size: 16px;
  font-weight: 700;
  margin: 0 0 5px;
  color: var(--paper);
}

.page-about .cadence li p {
  margin: 0;
  font-size: 14px;
  color: var(--mist);
}

/* ===== 结尾 ===== */
.page-about .about-cta {
  margin-top: clamp(26px, 4vw, 44px);
  border: 1px solid var(--line-blue);
  background:
    linear-gradient(140deg, rgba(124, 255, 107, 0.09), rgba(14, 27, 44, 0) 62%),
    var(--panel);
  padding: clamp(20px, 4vw, 34px);
}

.page-about .cta-title {
  font-family: var(--font-serif);
  font-size: clamp(20px, 3.2vw, 26px);
  font-weight: 800;
  margin: 0 0 10px;
  color: var(--paper);
}

.page-about .cta-text {
  color: var(--mist);
  font-size: 15px;
  max-width: 60ch;
}

.page-about .cta-links {
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
  margin-top: 16px;
}

.page-about .cta-links .btn {
  text-decoration: none;
}

/* ===== 桌面端 ===== */
@media (min-width: 720px) {
  .page-about .hero-stats {
    grid-template-columns: repeat(4, minmax(0, 1fr));
  }

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

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

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

@media (min-width: 900px) {
  .page-about .net-wrap {
    grid-template-columns: minmax(0, 0.9fr) minmax(0, 1.1fr);
    align-items: start;
    gap: 26px;
  }

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

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

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

  .page-about .flow li + li {
    border-left-width: 0;
  }
}

@media (min-width: 980px) {
  .page-about .about-body {
    display: grid;
    grid-template-columns: 236px minmax(0, 1fr);
    gap: clamp(24px, 3.6vw, 52px);
    align-items: start;
  }

  .page-about .index-rail {
    position: sticky;
    top: calc(var(--header-h) + 18px);
    margin-bottom: 0;
  }

  .page-about .rail-list {
    flex-direction: column;
    gap: 6px;
    overflow: visible;
  }

  .page-about .rail-list a {
    display: block;
    white-space: normal;
  }

  .page-about .about-hero h1 {
    max-width: 16ch;
  }
}

@media (prefers-reduced-motion: reduce) {
  .page-about .rail-list a,
  .page-about .net-node {
    transition: none;
  }
}