.page-about {
  --about-rail-w: 300px;
  --about-hero-pad-top: calc(var(--header-h) + clamp(34px, 6vw, 78px));
}

/* ---------------- 首屏 ---------------- */
.page-about .about-hero {
  position: relative;
  overflow: hidden;
  padding-block: var(--about-hero-pad-top) clamp(44px, 7vw, 96px);
  background:
    radial-gradient(120% 92% at 88% 4%, rgba(45, 226, 230, .14), transparent 62%),
    radial-gradient(90% 84% at 2% 98%, rgba(123, 97, 255, .20), transparent 60%),
    var(--deep-sea);
  border-bottom: 3px solid var(--char);
}

.page-about .about-hero::before {
  content: "";
  position: absolute;
  inset: 0;
  background-image:
    linear-gradient(to right, rgba(155, 176, 193, .10) 1px, transparent 1px),
    linear-gradient(to bottom, rgba(155, 176, 193, .08) 1px, transparent 1px);
  background-size: 74px 74px;
  -webkit-mask-image: linear-gradient(to bottom, #000 0%, transparent 80%);
  mask-image: linear-gradient(to bottom, #000 0%, transparent 80%);
  pointer-events: none;
}

.page-about .about-hero-inner {
  position: relative;
  z-index: 1;
}

.page-about .breadcrumbs {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 8px;
  margin-bottom: clamp(24px, 4.5vw, 46px);
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: .14em;
  color: var(--mist);
}

.page-about .breadcrumbs a {
  color: var(--cyan);
  text-decoration: none;
  border-bottom: 1px solid transparent;
  transition: border-color .2s var(--ease);
}

.page-about .breadcrumbs a:hover {
  border-bottom-color: var(--cyan);
}

.page-about .about-hero-grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: clamp(30px, 5vw, 58px);
}

.page-about .about-hero h1 {
  margin: 0 0 clamp(18px, 2.4vw, 26px);
  font-weight: 200;
  font-size: clamp(2.5rem, 8.4vw, 5.4rem);
  line-height: 1.03;
  letter-spacing: -.022em;
  color: var(--ice);
}

.page-about .about-hero .lead {
  max-width: 62ch;
  margin: 0;
  color: var(--mist);
  font-size: clamp(1rem, 1.5vw, 1.125rem);
  line-height: 1.75;
}

.page-about .about-hero-actions {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
  margin-top: clamp(22px, 3vw, 34px);
}

/* 首屏右侧指标面板 */
.page-about .about-hero-metrics {
  margin: 0;
  border-top: 1px solid var(--line-soft);
}

.page-about .about-metric {
  display: flex;
  align-items: baseline;
  justify-content: space-between;
  gap: 14px;
  padding: 15px 0;
  border-bottom: 1px solid var(--line-soft);
}

.page-about .about-metric dt {
  font-size: 12.5px;
  letter-spacing: .16em;
  color: var(--mist);
}

.page-about .about-metric dd {
  margin: 0;
  display: flex;
  align-items: baseline;
  gap: 5px;
}

.page-about .about-metric-num {
  font-family: var(--font-mono);
  font-size: clamp(1.5rem, 3.4vw, 2.1rem);
  font-weight: 700;
  line-height: 1;
  color: var(--cyan);
}

.page-about .about-metric-unit {
  font-size: 12.5px;
  letter-spacing: .1em;
  color: var(--mist);
}

.page-about .about-metric:first-child .about-metric-num {
  color: var(--flare);
}

/* ---------------- 编辑部两栏通用 ---------------- */
.page-about .about-editorial {
  display: grid;
  grid-template-columns: 1fr;
  gap: clamp(22px, 4vw, 46px);
  margin-bottom: clamp(30px, 5vw, 58px);
}

.page-about .about-editorial-rail {
  border-left: 4px solid var(--cyan);
  padding-left: 18px;
}

.page-about .about-rail-title {
  margin: 10px 0 14px;
  font-weight: 200;
  font-size: clamp(1.7rem, 4.6vw, 2.9rem);
  line-height: 1.14;
  letter-spacing: -.018em;
  color: var(--ice);
}

.page-about .about-rail-note {
  margin: 0;
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: .1em;
  color: var(--mist);
}

.page-about .about-editorial-body.prose {
  max-width: 68ch;
  color: var(--ice);
}

.page-about .about-editorial-body.prose p {
  margin: 0 0 1.1em;
  line-height: 1.8;
  color: var(--mist);
}

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

.page-about .about-inline-link {
  color: var(--mist);
}

.page-about .about-inline-link a {
  color: var(--cyan);
  text-decoration: none;
  border-bottom: 1px solid var(--cyan-a18);
  transition: border-color .2s var(--ease), color .2s var(--ease);
}

.page-about .about-inline-link a:hover {
  border-bottom-color: var(--cyan);
  color: var(--ice);
}

/* ---------------- 01 品牌起点 ---------------- */
.page-about .about-origin {
  background: var(--deep-sea);
}

.page-about .about-duo {
  display: grid;
  grid-template-columns: 1fr;
  gap: clamp(20px, 3vw, 32px);
}

.page-about .about-duo-figure {
  margin: 0;
  border: 3px solid var(--char);
  box-shadow: var(--shadow-hard);
  background: var(--midnight);
  overflow: hidden;
}

.page-about .about-duo-figure img {
  display: block;
  width: 100%;
  height: auto;
  aspect-ratio: 14 / 9;
  object-fit: cover;
  filter: saturate(.9) contrast(1.05);
}

.page-about .media-caption {
  display: block;
  padding: 12px 16px;
  font-size: 12.5px;
  line-height: 1.6;
  color: var(--mist);
  border-top: 1px solid var(--line-soft);
}

.page-about .about-map-card {
  border: 3px solid var(--char);
  box-shadow: var(--shadow-hard);
  background:
    radial-gradient(80% 80% at 50% 50%, rgba(45, 226, 230, .10), transparent 70%),
    var(--midnight);
  padding: clamp(16px, 3vw, 26px);
  display: flex;
  flex-direction: column;
  gap: 12px;
}

.page-about .about-map-caption {
  margin: 0;
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: .14em;
  color: var(--mist);
}

.page-about .about-map-svg {
  display: block;
  width: 100%;
  max-width: 460px;
  height: auto;
  margin: 0 auto;
}

.page-about .about-map-rings circle {
  fill: none;
  stroke: var(--line-soft);
  stroke-width: 1;
  stroke-dasharray: 3 6;
}

.page-about .about-map-spokes line {
  stroke: var(--cyan);
  stroke-width: 1.2;
  opacity: .42;
}

.page-about .about-map-nodes .about-node {
  fill: var(--deep-sea);
  stroke: var(--cyan);
  stroke-width: 2;
  transition: fill .25s var(--ease), stroke .25s var(--ease), r .25s var(--ease);
}

.page-about .about-map-nodes .about-node--hub {
  fill: var(--flare);
  stroke: var(--ice);
  stroke-width: 2.5;
}

.page-about .about-node-label {
  fill: var(--mist);
  font-family: var(--font-mono);
  font-size: 15px;
  text-anchor: middle;
  letter-spacing: .06em;
}

.page-about .about-node-label--hub {
  fill: var(--ice);
  font-family: var(--font-body);
  font-weight: 700;
  font-size: 17px;
}

.page-about .about-map-nodes .about-node:hover {
  fill: var(--cyan);
  stroke: var(--ice);
}

/* ---------------- 02 编辑与版本 ---------------- */
.page-about .about-method {
  border-block: 3px solid var(--char);
}

.page-about .about-method-head {
  max-width: 74ch;
  margin-bottom: clamp(28px, 4.5vw, 50px);
}

.page-about .about-method-head .section-title {
  margin: 10px 0 16px;
}

.page-about .about-method-lead {
  margin: 0;
  color: var(--mist);
  font-size: 1.0625rem;
  line-height: 1.78;
}

.page-about .about-method-grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: clamp(22px, 3.4vw, 38px);
}

.page-about .about-method-figure {
  margin: 0;
  align-self: start;
  border: 3px solid var(--char);
  box-shadow: var(--shadow-hard);
  background: var(--deep-sea);
  overflow: hidden;
}

.page-about .about-method-figure img {
  display: block;
  width: 100%;
  height: auto;
  aspect-ratio: 3 / 2;
  object-fit: cover;
}

.page-about .about-steps {
  list-style: none;
  margin: 0;
  padding: 0;
  display: grid;
  gap: 16px;
}

.page-about .about-step {
  position: relative;
  padding: 20px 20px 20px 24px;
  background: var(--deep-sea);
  border: 2px solid var(--line-soft);
  border-left: 6px solid var(--cyan);
}

.page-about .about-step.panel--violet {
  border-left-color: var(--violet);
}

.page-about .about-step.panel--wine {
  border-left-color: var(--wine);
}

.page-about .about-step-num {
  display: inline-block;
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: .2em;
  color: var(--cyan);
  margin-bottom: 8px;
}

.page-about .about-step.panel--violet .about-step-num {
  color: var(--violet);
}

.page-about .about-step.panel--wine .about-step-num {
  color: var(--wine);
  color: #d0698a;
}

.page-about .about-step .panel-title {
  margin: 0 0 10px;
  font-size: 1.0625rem;
  font-weight: 700;
  color: var(--ice);
}

.page-about .about-step p {
  margin: 0;
  color: var(--mist);
  font-size: .9375rem;
  line-height: 1.8;
}

/* ---------------- 03 长期跟队 ---------------- */
.page-about .about-follow {
  background:
    linear-gradient(180deg, var(--deep-sea) 0%, #0d2135 100%);
}

.page-about .about-follow-grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: clamp(24px, 4vw, 48px);
  align-items: center;
}

.page-about .about-follow-copy .prose p {
  margin: 0 0 1.05em;
  color: var(--mist);
  line-height: 1.82;
}

.page-about .about-follow-tags {
  list-style: none;
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
  margin: 20px 0;
  padding: 0;
}

.page-about .about-follow-figure {
  margin: 0;
  border: 3px solid var(--char);
  box-shadow: var(--shadow-hard);
  background: var(--midnight);
  overflow: hidden;
  transform: rotate(-.6deg);
}

.page-about .about-follow-figure img {
  display: block;
  width: 100%;
  height: auto;
  aspect-ratio: 8 / 5;
  object-fit: cover;
}

/* ---------------- 04 团队与协作 ---------------- */
.page-about .about-team {
  border-block: 3px solid var(--char);
}

.page-about .about-team-head {
  max-width: 60ch;
  margin-bottom: clamp(24px, 4vw, 42px);
}

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

.page-about .about-tab-input {
  position: absolute;
  width: 1px;
  height: 1px;
  opacity: 0;
  pointer-events: none;
}

.page-about .about-tabbar {
  display: grid;
  grid-template-columns: 1fr;
  gap: 8px;
  margin-bottom: 20px;
}

.page-about .about-tab-label {
  display: block;
  padding: 13px 16px;
  font-family: var(--font-mono);
  font-size: 12.5px;
  letter-spacing: .08em;
  color: var(--mist);
  background: rgba(5, 17, 28, .45);
  border: 2px solid var(--line-soft);
  cursor: pointer;
  transition: color .2s var(--ease), border-color .2s var(--ease), background .2s var(--ease);
}

.page-about .about-tab-label:hover {
  color: var(--ice);
  border-color: var(--cyan-a18);
}

.page-about .about-tabpanel {
  display: none;
  padding: clamp(20px, 3vw, 30px);
  background: rgba(5, 17, 28, .55);
  border: 2px solid var(--line-soft);
  border-left: 6px solid var(--cyan);
}

.page-about .about-tabpanel p {
  margin: 0;
  color: var(--ice);
  line-height: 1.82;
  font-size: 1rem;
}

#about-tab-edit:checked ~ .about-tabbar label[for="about-tab-edit"],
#about-tab-ux:checked ~ .about-tabbar label[for="about-tab-ux"],
#about-tab-ops:checked ~ .about-tabbar label[for="about-tab-ops"],
#about-tab-biz:checked ~ .about-tabbar label[for="about-tab-biz"] {
  color: var(--char);
  background: var(--cyan);
  border-color: var(--cyan);
}

#about-tab-edit:focus-visible ~ .about-tabbar label[for="about-tab-edit"],
#about-tab-ux:focus-visible ~ .about-tabbar label[for="about-tab-ux"],
#about-tab-ops:focus-visible ~ .about-tabbar label[for="about-tab-ops"],
#about-tab-biz:focus-visible ~ .about-tabbar label[for="about-tab-biz"] {
  outline: 3px solid var(--flare);
  outline-offset: 2px;
}

#about-tab-edit:checked ~ .about-tabpanels [data-for="edit"],
#about-tab-ux:checked ~ .about-tabpanels [data-for="ux"],
#about-tab-ops:checked ~ .about-tabpanels [data-for="ops"],
#about-tab-biz:checked ~ .about-tabpanels [data-for="biz"] {
  display: block;
}

/* ---------------- 05 里程碑 ---------------- */
.page-about .about-milestones {
  background: var(--deep-sea);
}

.page-about .about-timeline {
  list-style: none;
  margin: 0;
  padding: 0;
  position: relative;
  display: grid;
  gap: 14px;
}

.page-about .about-timeline::before {
  content: "";
  position: absolute;
  left: 15px;
  top: 6px;
  bottom: 6px;
  width: 2px;
  background: linear-gradient(180deg, var(--cyan), var(--violet) 60%, var(--wine));
  opacity: .55;
}

.page-about .about-tl-item {
  position: relative;
  padding-left: 44px;
}

.page-about .about-tl-item::before {
  content: "";
  position: absolute;
  left: 8px;
  top: 20px;
  width: 16px;
  height: 16px;
  background: var(--deep-sea);
  border: 3px solid var(--cyan);
  border-radius: 50%;
}

.page-about .about-tl-node {
  border: 2px solid var(--line-soft);
  background: var(--midnight);
  transition: border-color .22s var(--ease), box-shadow .22s var(--ease);
}

.page-about .about-tl-node[open] {
  border-color: var(--cyan);
  box-shadow: var(--shadow-soft);
}

.page-about .about-tl-node summary {
  list-style: none;
  cursor: pointer;
  display: flex;
  flex-wrap: wrap;
  align-items: baseline;
  gap: 10px 16px;
  padding: 16px 18px;
}

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

.page-about .about-tl-year {
  font-family: var(--font-mono);
  font-size: 1.25rem;
  font-weight: 700;
  color: var(--flare);
  letter-spacing: .02em;
}

.page-about .about-tl-title {
  flex: 1 1 160px;
  font-size: 1rem;
  font-weight: 700;
  color: var(--ice);
}

.page-about .about-tl-mark {
  position: relative;
  width: 16px;
  height: 16px;
  flex: none;
}

.page-about .about-tl-mark::before,
.page-about .about-tl-mark::after {
  content: "";
  position: absolute;
  background: var(--cyan);
  transition: transform .22s var(--ease), opacity .22s var(--ease);
}

.page-about .about-tl-mark::before {
  left: 0;
  top: 7px;
  width: 16px;
  height: 2px;
}

.page-about .about-tl-mark::after {
  left: 7px;
  top: 0;
  width: 2px;
  height: 16px;
}

.page-about .about-tl-node[open] .about-tl-mark::after {
  transform: scaleY(0);
  opacity: 0;
}

.page-about .about-tl-body {
  padding: 0 18px 18px;
  color: var(--mist);
  font-size: .9375rem;
  line-height: 1.82;
  border-top: 1px solid var(--line-soft);
  padding-top: 14px;
  margin-top: 2px;
}

/* ---------------- 引用块 ---------------- */
.page-about .about-quote-section {
  border-block: 3px solid var(--char);
}

.page-about .about-quote {
  margin: 0;
  padding: clamp(24px, 4.4vw, 48px) clamp(20px, 4vw, 52px);
  border: 3px solid var(--char);
  border-left: 8px solid var(--gold);
  box-shadow: var(--shadow-hard);
  background: rgba(5, 17, 28, .82);
}

.page-about .about-quote p {
  margin: 0 0 16px;
  font-weight: 200;
  font-size: clamp(1.2rem, 3.2vw, 1.9rem);
  line-height: 1.5;
  color: var(--ice);
  letter-spacing: -.01em;
}

.page-about .about-quote-source {
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: .14em;
  color: var(--mist);
}

/* ---------------- 06 下一步 ---------------- */
.page-about .about-next {
  padding-bottom: clamp(56px, 8vw, 112px);
}

.page-about .about-next-grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: clamp(24px, 4vw, 44px);
  align-items: start;
}

.page-about .about-next-copy .section-title {
  margin: 10px 0 16px;
}

.page-about .about-next-copy .prose {
  margin: 0;
  color: var(--mist);
  line-height: 1.82;
}

.page-about .about-next-actions {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
  margin-top: 24px;
}

.page-about .about-next-card {
  padding: clamp(20px, 3vw, 30px);
  background: var(--deep-sea);
  border: 2px solid var(--line-soft);
  border-left: 6px solid var(--flare);
}

.page-about .about-next-card .panel-title {
  margin: 0 0 16px;
  font-size: .8125rem;
  letter-spacing: .18em;
  font-family: var(--font-mono);
  color: var(--flare);
  font-weight: 400;
}

.page-about .about-next-list {
  list-style: none;
  margin: 0;
  padding: 0;
  display: grid;
  gap: 14px;
}

.page-about .about-next-list li {
  display: grid;
  grid-template-columns: 34px 1fr;
  gap: 12px;
  align-items: baseline;
  color: var(--mist);
  font-size: .9375rem;
  line-height: 1.75;
  padding-bottom: 14px;
  border-bottom: 1px solid var(--line-soft);
}

.page-about .about-next-list li:last-child {
  padding-bottom: 0;
  border-bottom: 0;
}

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

.page-about .about-next-list a {
  color: var(--ice);
  text-decoration: none;
  border-bottom: 1px solid var(--cyan-a18);
  transition: border-color .2s var(--ease), color .2s var(--ease);
}

.page-about .about-next-list a:hover {
  color: var(--cyan);
  border-bottom-color: var(--cyan);
}

/* ---------------- 响应式 ---------------- */
@media (min-width: 700px) {
  .page-about .about-tabbar {
    grid-template-columns: repeat(2, 1fr);
  }

  .page-about .about-duo {
    grid-template-columns: minmax(0, 1.4fr) minmax(0, 1fr);
    align-items: stretch;
  }
}

@media (min-width: 900px) {
  .page-about {
    --about-hero-pad-top: calc(var(--header-h) + clamp(48px, 7vw, 104px));
  }

  .page-about .about-hero-grid {
    grid-template-columns: minmax(0, 1.55fr) minmax(0, .8fr);
    align-items: end;
    gap: clamp(38px, 5vw, 72px);
  }

  .page-about .about-editorial {
    grid-template-columns: var(--about-rail-w) minmax(0, 1fr);
    gap: clamp(30px, 4vw, 60px);
  }

  .page-about .about-editorial-rail {
    position: sticky;
    top: calc(var(--header-h) + 26px);
    align-self: start;
  }

  .page-about .about-method-grid {
    grid-template-columns: minmax(0, .95fr) minmax(0, 1.15fr);
    align-items: start;
    gap: clamp(28px, 4vw, 52px);
  }

  .page-about .about-follow-grid {
    grid-template-columns: minmax(0, 1.15fr) minmax(0, .85fr);
    gap: clamp(34px, 4.6vw, 64px);
  }

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

  .page-about .about-next-grid {
    grid-template-columns: minmax(0, 1.2fr) minmax(0, .8fr);
    gap: clamp(32px, 4.4vw, 60px);
  }
}

@media (min-width: 1180px) {
  .page-about .about-duo {
    grid-template-columns: minmax(0, 1.5fr) minmax(0, 1fr);
  }

  .page-about .about-follow-figure {
    transform: rotate(-1deg) translateY(-6px);
  }
}

@media (max-width: 420px) {
  .page-about .about-tl-item {
    padding-left: 34px;
  }

  .page-about .about-timeline::before {
    left: 11px;
  }

  .page-about .about-tl-item::before {
    left: 4px;
    width: 14px;
    height: 14px;
  }

  .page-about .about-next-list li {
    grid-template-columns: 1fr;
    gap: 6px;
  }
}

@media (prefers-reduced-motion: reduce) {
  .page-about .about-tl-mark::before,
  .page-about .about-tl-mark::after,
  .page-about .about-tab-label,
  .page-about .about-tl-node,
  .page-about .about-map-nodes .about-node {
    transition: none !important;
  }
}