.page-about {
  --about-rail-w: 222px;
  --about-gap: 56px;
  padding-bottom: 88px;
}

/* ---------- 封面 ---------- */
.page-about .about-cover {
  padding: 22px 0 32px;
}

.page-about .about-cover-grid {
  display: grid;
  gap: 32px;
}

.page-about .about-cover-copy .display-title {
  margin: 12px 0 0;
  max-width: 18ch;
}

.page-about .about-cover-copy .lede {
  margin: 20px 0 0;
  max-width: 58ch;
}

.page-about .about-glance {
  border: 1px solid var(--line);
  border-radius: var(--radius-m);
  padding: 20px 22px 22px;
  background:
    linear-gradient(158deg, rgba(56, 242, 216, 0.09), rgba(11, 18, 48, 0) 62%),
    var(--ink-800);
  box-shadow: var(--shadow-soft);
}

.page-about .about-glance-list {
  margin: 16px 0 0;
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 14px 18px;
}

.page-about .about-glance-item dt {
  font-size: 13px;
  color: var(--muted);
  letter-spacing: 0.02em;
}

.page-about .about-glance-item dd {
  margin: 5px 0 0;
  font-size: 19px;
  font-weight: 700;
  color: var(--white);
}

.page-about .about-glance-item .num {
  color: var(--cyan);
}

.page-about .about-glance-item .mono {
  font-family: var(--font-mono);
  color: var(--orange);
  font-size: 18px;
}

.page-about .about-banner {
  margin: 0 0 56px;
}

/* ---------- 骨架：索引栏 + 正文 ---------- */
.page-about .about-layout {
  display: grid;
  gap: 36px;
}

.page-about .about-rail .index-list {
  list-style: none;
  margin: 14px 0 0;
  padding: 0;
  display: flex;
  gap: 18px;
  overflow-x: auto;
}

.page-about .about-rail .index-link {
  display: inline-flex;
  align-items: baseline;
  gap: 8px;
  white-space: nowrap;
  padding: 6px 0;
  font-size: 14px;
  color: var(--muted);
  text-decoration: none;
  border-bottom: 1px solid transparent;
  transition: color 0.2s var(--ease), border-color 0.2s var(--ease);
}

.page-about .about-rail .index-link .num {
  font-family: var(--font-mono);
  font-size: 12px;
  color: var(--line);
  transition: color 0.2s var(--ease);
}

.page-about .about-rail .index-link:hover,
.page-about .about-rail .index-link:focus-visible {
  color: var(--white);
}

.page-about .about-rail .index-link[aria-current] {
  color: var(--cyan);
  border-bottom-color: var(--cyan);
}

.page-about .about-rail .index-link[aria-current] .num {
  color: var(--cyan);
}

/* ---------- 章节通用 ---------- */
.page-about .about-sec {
  padding: 38px 0;
  border-top: 1px solid var(--line-soft);
  scroll-margin-top: calc(var(--header-h) + 26px);
}

.page-about .about-sec:first-child {
  border-top: 0;
  padding-top: 0;
}

.page-about .about-sec-num {
  color: var(--cyan);
  letter-spacing: 0.22em;
}

.page-about .about-sec .section-title {
  margin: 10px 0 0;
}

.page-about .about-lede {
  margin: 16px 0 0;
  max-width: 60ch;
  color: var(--muted);
  line-height: 1.8;
}

.page-about .about-statement {
  margin: 26px 0 0;
  padding-left: 18px;
  border-left: 2px solid var(--orange);
  font-family: var(--font-display);
  font-size: 23px;
  line-height: 1.5;
  color: var(--white);
  max-width: 26ch;
}

.page-about .about-prose {
  margin: 24px 0 0;
  max-width: 66ch;
  color: var(--muted);
}

.page-about .about-prose p {
  margin: 0 0 16px;
  line-height: 1.85;
}

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

/* ---------- 发展历程 ---------- */
.page-about .about-year-jump {
  margin: 24px 0 0;
  flex-wrap: wrap;
}

.page-about .about-year-jump .chip {
  font-family: var(--font-mono);
  text-decoration: none;
  letter-spacing: 0.04em;
}

.page-about .about-timeline {
  list-style: none;
  margin: 28px 0 0;
  padding: 0;
  position: relative;
}

.page-about .about-timeline::before {
  content: "";
  position: absolute;
  left: 5px;
  top: 12px;
  bottom: 12px;
  width: 1px;
  background: linear-gradient(180deg, var(--cyan), rgba(56, 242, 216, 0.12) 55%, var(--line));
}

.page-about .about-timeline-item {
  position: relative;
  padding: 0 0 34px 32px;
  scroll-margin-top: calc(var(--header-h) + 30px);
}

.page-about .about-timeline-item::before {
  content: "";
  position: absolute;
  left: 0;
  top: 7px;
  width: 11px;
  height: 11px;
  border-radius: 50%;
  background: var(--ink-900);
  border: 1px solid var(--cyan);
  box-shadow: 0 0 0 4px rgba(56, 242, 216, 0.09);
  transition: background 0.25s var(--ease), border-color 0.25s var(--ease), box-shadow 0.25s var(--ease);
}

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

.page-about .about-year {
  margin: 0;
  font-family: var(--font-mono);
  font-size: 15px;
  letter-spacing: 0.1em;
  color: var(--cyan);
}

.page-about .about-node-title {
  margin: 8px 0 8px;
  font-size: 18px;
  line-height: 1.4;
}

.page-about .about-timeline-item > p:not(.about-year) {
  margin: 0;
  max-width: 62ch;
  color: var(--muted);
  line-height: 1.85;
}

.page-about .about-timeline-item:target::before {
  background: var(--orange);
  border-color: var(--orange);
  box-shadow: 0 0 0 7px rgba(255, 122, 47, 0.16);
}

.page-about .about-timeline-item:target .about-year {
  color: var(--orange);
}

/* ---------- 内容团队 ---------- */
.page-about .about-team-grid {
  display: grid;
  gap: 16px;
  margin-top: 28px;
}

.page-about .about-team-card {
  border: 1px solid var(--line);
  border-radius: var(--radius-m);
  padding: 22px 22px 18px;
  background: var(--ink-700);
  transition: border-color 0.25s var(--ease), transform 0.25s var(--ease);
}

.page-about .about-team-card:hover {
  border-color: rgba(56, 242, 216, 0.42);
}

.page-about .about-team-name {
  margin: 0;
  font-size: 18px;
}

.page-about .about-team-tag {
  margin: 9px 0 0;
  font-family: var(--font-mono);
  font-size: 12.5px;
  letter-spacing: 0.04em;
  color: var(--cyan);
}

.page-about .about-team-more {
  margin-top: 16px;
  padding-top: 12px;
  border-top: 1px solid var(--line-soft);
}

.page-about .about-team-more summary {
  display: flex;
  align-items: center;
  gap: 8px;
  list-style: none;
  cursor: pointer;
  font-size: 14px;
  color: var(--muted);
  transition: color 0.2s var(--ease);
}

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

.page-about .about-team-more summary::before {
  content: "+";
  font-family: var(--font-mono);
  color: var(--orange);
  font-size: 15px;
}

.page-about .about-team-more[open] summary::before {
  content: "–";
}

.page-about .about-team-more summary:hover,
.page-about .about-team-more summary:focus-visible {
  color: var(--white);
}

.page-about .about-team-more ul {
  margin: 12px 0 0;
  padding-left: 18px;
  font-size: 15px;
  line-height: 1.85;
  color: var(--muted);
}

.page-about .about-team-more li {
  margin-bottom: 6px;
}

.page-about .about-team-figure {
  margin: 28px 0 0;
  aspect-ratio: 3 / 2;
}

/* ---------- 流程 ---------- */
.page-about .about-flow {
  list-style: none;
  margin: 26px 0 0;
  padding: 0;
  display: grid;
  gap: 0;
}

.page-about .about-flow-step {
  padding: 20px 0 22px;
  border-top: 1px solid var(--line-soft);
}

.page-about .about-flow-step:last-child {
  border-bottom: 1px solid var(--line-soft);
}

.page-about .about-flow-num {
  margin: 0;
  font-family: var(--font-mono);
  font-size: 26px;
  letter-spacing: 0.04em;
  color: rgba(56, 242, 216, 0.6);
}

.page-about .about-flow-step h3 {
  margin: 6px 0 9px;
  font-size: 17px;
}

.page-about .about-flow-step p {
  margin: 0;
  max-width: 48ch;
  color: var(--muted);
  line-height: 1.85;
}

/* ---------- 合作生态 ---------- */
.page-about .about-eco {
  display: grid;
  gap: 30px;
  margin-top: 26px;
}

.page-about .about-eco-list {
  list-style: none;
  margin: 22px 0 0;
  padding: 0;
  display: grid;
  gap: 20px;
}

.page-about .about-eco-list li {
  padding-left: 16px;
  border-left: 1px solid var(--line);
}

.page-about .about-eco-list p {
  margin: 10px 0 0;
  max-width: 52ch;
  color: var(--muted);
  line-height: 1.85;
}

.page-about .about-eco-figure {
  margin: 0;
  aspect-ratio: 4 / 3;
}

.page-about .about-web {
  margin: 36px 0 0;
}

.page-about .about-web-svg {
  display: block;
  width: 100%;
  height: auto;
}

.page-about .about-web-svg line {
  stroke: var(--line);
  stroke-width: 1;
}

.page-about .about-web-svg text {
  font-family: var(--font-sans);
  font-size: 14px;
  text-anchor: middle;
  fill: var(--muted);
}

.page-about .about-web-svg .web-node circle {
  fill: var(--ink-700);
  stroke: var(--line);
  stroke-width: 1;
  transition: fill 0.22s var(--ease), stroke 0.22s var(--ease);
}

.page-about .about-web-svg .web-node--org circle {
  stroke: rgba(56, 242, 216, 0.45);
}

.page-about .about-web-svg .web-node--data circle {
  stroke: rgba(255, 122, 47, 0.5);
}

.page-about .about-web-svg .web-node--media circle {
  stroke: rgba(255, 61, 139, 0.42);
}

.page-about .about-web-svg .web-node:hover circle {
  fill: rgba(56, 242, 216, 0.16);
  stroke: var(--cyan);
}

.page-about .about-web-svg .web-node--data:hover circle {
  fill: rgba(255, 122, 47, 0.18);
  stroke: var(--orange);
}

.page-about .about-web-svg .web-node--media:hover circle {
  fill: rgba(255, 61, 139, 0.16);
  stroke: var(--magenta);
}

.page-about .about-web-svg .web-center circle {
  fill: var(--score-bg);
  stroke: var(--cyan);
  stroke-width: 1.5;
}

.page-about .about-web-svg .web-center-label {
  fill: var(--white);
  font-size: 15px;
  font-weight: 700;
}

.page-about .about-badges {
  list-style: none;
  margin: 28px 0 0;
  padding: 0;
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
}

.page-about .about-badges li {
  border: 1px solid var(--line);
  border-radius: 999px;
  padding: 8px 16px;
  font-family: var(--font-mono);
  font-size: 12.5px;
  letter-spacing: 0.02em;
  color: var(--muted);
}

/* ---------- 服务承诺 ---------- */
.page-about .about-promise-grid {
  display: grid;
  gap: 22px;
  margin-top: 28px;
}

.page-about .about-promise-item {
  padding-top: 16px;
  border-top: 2px solid var(--cyan);
}

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

.page-about .about-promise-item:nth-child(3) {
  border-top-color: var(--magenta);
}

.page-about .about-promise-num {
  margin: 0;
  font-family: var(--font-mono);
  font-size: 28px;
  letter-spacing: -0.01em;
  color: var(--white);
}

.page-about .about-promise-item h3 {
  margin: 10px 0 8px;
  font-size: 16px;
  color: var(--cyan);
}

.page-about .about-promise-item:nth-child(2) h3 {
  color: var(--orange);
}

.page-about .about-promise-item:nth-child(3) h3 {
  color: var(--magenta);
}

.page-about .about-promise-item p {
  margin: 0;
  font-size: 15px;
  line-height: 1.8;
  color: var(--muted);
}

.page-about .about-feedback {
  margin-top: 34px;
  padding: 26px 24px;
  border: 1px solid var(--line);
  border-radius: var(--radius-l);
  background:
    linear-gradient(140deg, rgba(255, 122, 47, 0.11), rgba(11, 18, 48, 0) 62%),
    var(--ink-700);
}

.page-about .about-feedback h3 {
  margin: 0 0 10px;
  font-size: 20px;
}

.page-about .about-feedback p {
  margin: 0;
  max-width: 68ch;
  color: var(--muted);
  line-height: 1.85;
}

.page-about .about-actions {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
  margin-top: 20px;
}

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

/* ---------- 收尾入口 ---------- */
.page-about .about-cta {
  margin-top: 12px;
  padding-top: 34px;
  border-top: 1px solid var(--line-soft);
  display: grid;
  gap: 20px;
}

.page-about .about-cta .section-title {
  margin: 8px 0 0;
}

.page-about .about-cta .about-actions {
  margin-top: 0;
}

/* ---------- 断点 ---------- */
@media (min-width: 760px) {
  .page-about .about-statement {
    font-size: 29px;
    max-width: 30ch;
  }

  .page-about .about-timeline-item {
    display: grid;
    grid-template-columns: 84px minmax(0, 1fr);
    column-gap: 26px;
  }

  .page-about .about-timeline-item .about-year {
    grid-column: 1;
    grid-row: 1;
    margin-top: 3px;
  }

  .page-about .about-node-title {
    grid-column: 2;
    grid-row: 1;
  }

  .page-about .about-timeline-item > p:not(.about-year) {
    grid-column: 2;
    grid-row: 2;
  }

  .page-about .about-team-grid {
    grid-template-columns: repeat(2, minmax(0, 1fr));
    gap: 20px;
  }

  .page-about .about-flow {
    grid-template-columns: repeat(2, minmax(0, 1fr));
    column-gap: 48px;
  }

  .page-about .about-flow-step:nth-child(even) {
    border-bottom: 1px solid var(--line-soft);
  }

  .page-about .about-promise-grid {
    grid-template-columns: repeat(3, minmax(0, 1fr));
    gap: 30px;
  }

  .page-about .about-cta {
    grid-template-columns: minmax(0, 1fr) auto;
    align-items: center;
    gap: 32px;
  }
}

@media (min-width: 900px) {
  .page-about .about-cover {
    padding: 30px 0 40px;
  }

  .page-about .about-cover-grid {
    grid-template-columns: minmax(0, 7fr) minmax(0, 4fr);
    gap: 52px;
    align-items: end;
  }

  .page-about .about-glance {
    padding: 24px 26px 26px;
  }

  .page-about .about-eco {
    grid-template-columns: minmax(0, 6fr) minmax(0, 5fr);
    gap: 46px;
    align-items: start;
  }

  .page-about .about-eco-figure {
    margin-top: 6px;
  }
}

@media (min-width: 1000px) {
  .page-about .about-layout {
    grid-template-columns: var(--about-rail-w) minmax(0, 1fr);
    gap: 64px;
  }

  .page-about .about-rail {
    position: sticky;
    top: calc(var(--header-h) + 32px);
    align-self: start;
  }

  .page-about .about-rail .index-list {
    flex-direction: column;
    gap: 0;
    overflow-x: visible;
  }

  .page-about .about-rail .index-link {
    display: flex;
    border-bottom: 0;
    border-left: 1px solid var(--line);
    padding: 8px 0 8px 14px;
  }

  .page-about .about-rail .index-link[aria-current] {
    border-left-color: var(--cyan);
  }
}

@media (min-width: 1200px) {
  .page-about .about-sec {
    padding: 48px 0;
  }

  .page-about .about-statement {
    font-size: 32px;
  }
}

@media (prefers-reduced-motion: reduce) {
  .page-about .about-team-card,
  .page-about .about-timeline-item::before,
  .page-about .about-web-svg .web-node circle {
    transition: none;
  }
}