.page-about {
  --ab-grad: linear-gradient(115deg, var(--cyan) 0%, var(--lava) 100%);
  --ab-gap: 20px;
  padding-block: 20px 88px;
  background:
    radial-gradient(1100px 520px at 78% -6%, rgba(43, 233, 224, 0.10), transparent 62%),
    radial-gradient(820px 480px at 4% 30%, rgba(255, 106, 43, 0.08), transparent 66%),
    var(--void);
  color: var(--silver);
}

.page-about .container {
  width: 100%;
  max-width: var(--shell);
  margin-inline: auto;
  padding-inline: 20px;
}

.page-about .num {
  font-family: var(--font-mono);
  font-variant-numeric: tabular-nums;
}

/* ---------- 面包屑 ---------- */
.page-about .ab-top {
  padding-block: 4px 18px;
}

.page-about .breadcrumb {
  display: flex;
  align-items: center;
  gap: 8px;
  font-size: 12.5px;
  color: var(--index);
}

.page-about .breadcrumb a {
  color: var(--index);
  text-decoration: none;
  border-bottom: 1px solid transparent;
  transition: color var(--t-fast) var(--ease), border-color var(--t-fast) var(--ease);
}

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

.page-about .breadcrumb .ab-sep {
  color: var(--line);
}

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

/* ---------- 首屏 ---------- */
.page-about .ab-hero {
  position: relative;
  padding-block: 22px 46px;
}

.page-about .ab-hero::after {
  content: "";
  position: absolute;
  left: 20px;
  top: 0;
  width: 84px;
  height: 1px;
  background: var(--ab-grad);
}

.page-about .eyebrow {
  display: inline-flex;
  align-items: center;
  gap: 10px;
  margin: 0;
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.16em;
  text-transform: uppercase;
  color: var(--cyan);
}

.page-about .eyebrow::before {
  content: "";
  width: 26px;
  height: 1px;
  background: var(--cyan);
  flex: none;
}

.page-about .ab-hero-title {
  margin: 18px 0 0;
  font-family: var(--font-display);
  font-weight: 300;
  font-size: clamp(38px, 8.2vw, 96px);
  line-height: 1.02;
  letter-spacing: -0.02em;
  color: #fff;
  max-width: 16ch;
}

.page-about .ab-hero-lede {
  margin: 24px 0 0;
  max-width: 64ch;
  font-size: clamp(16px, 2.2vw, 18px);
  line-height: 1.8;
  color: var(--silver);
}

.page-about .ab-hero-meta {
  display: grid;
  grid-template-columns: 1fr;
  gap: 1px;
  margin: 34px 0 0;
  border: 1px solid var(--line);
  border-radius: 4px;
  background: var(--line);
  overflow: hidden;
}

.page-about .ab-hero-meta > div {
  background: var(--panel);
  padding: 15px 18px;
}

.page-about .ab-hero-meta dt {
  margin: 0;
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: 0.18em;
  text-transform: uppercase;
  color: var(--index);
}

.page-about .ab-hero-meta dd {
  margin: 6px 0 0;
  font-size: 15px;
  color: var(--silver);
}

.page-about .ab-hero-meta > div:first-child dd,
.page-about .ab-hero-meta > div:last-child dd {
  font-family: var(--font-mono);
  font-variant-numeric: tabular-nums;
}

/* ---------- 章节锚点条 ---------- */
.page-about .about-toc {
  position: sticky;
  top: 60px;
  z-index: 20;
  border-block: 1px solid var(--line);
  background: rgba(5, 7, 14, 0.86);
  backdrop-filter: blur(14px);
  -webkit-backdrop-filter: blur(14px);
}

.page-about .about-toc-inner {
  display: flex;
  align-items: center;
  gap: 14px;
  padding-block: 10px;
  overflow-x: auto;
  scrollbar-width: none;
}

.page-about .about-toc-inner::-webkit-scrollbar {
  display: none;
}

.page-about .about-toc-label {
  flex: none;
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: 0.18em;
  color: var(--index);
}

.page-about .about-toc-list {
  display: flex;
  align-items: center;
  gap: 4px;
  margin: 0;
  padding: 0;
  list-style: none;
}

.page-about .about-toc-list a {
  display: inline-flex;
  align-items: baseline;
  gap: 7px;
  padding: 7px 11px;
  border: 1px solid transparent;
  border-radius: 3px;
  font-size: 13px;
  white-space: nowrap;
  color: var(--index);
  text-decoration: none;
  transition: color var(--t-fast) var(--ease), border-color var(--t-fast) var(--ease), background var(--t-fast) var(--ease);
}

.page-about .about-toc-list a:hover,
.page-about .about-toc-list a:focus-visible {
  color: var(--silver);
  border-color: var(--line);
  background: var(--panel);
}

.page-about .about-toc-list .num {
  font-size: 11px;
  color: var(--cyan);
}

/* ---------- 通用章节骨架 ---------- */
.page-about .ab-section {
  padding-block: 56px 0;
}

.page-about .ab-split {
  display: grid;
  grid-template-columns: 1fr;
  gap: 18px;
}

.page-about .ab-rail {
  display: flex;
  align-items: baseline;
  gap: 12px;
  padding-bottom: 12px;
  border-bottom: 1px solid var(--line);
}

.page-about .ab-index {
  font-size: 26px;
  line-height: 1;
  color: var(--cyan);
}

.page-about .ab-rail-label {
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: 0.18em;
  text-transform: uppercase;
  color: var(--index);
}

.page-about .ab-h2 {
  margin: 0 0 18px;
  font-family: var(--font-display);
  font-weight: 300;
  font-size: clamp(27px, 5vw, 42px);
  line-height: 1.14;
  letter-spacing: -0.01em;
  color: #fff;
  max-width: 22ch;
}

.page-about .ab-body p {
  margin: 0 0 16px;
  max-width: 66ch;
  font-size: 16px;
  line-height: 1.85;
  color: var(--silver);
}

.page-about .ab-after {
  margin-top: 22px !important;
  padding-left: 14px;
  border-left: 2px solid var(--cyan);
  color: var(--index) !important;
  font-size: 14.5px !important;
}

.page-about .ab-link {
  color: var(--cyan);
  text-decoration: none;
  border-bottom: 1px solid rgba(43, 233, 224, 0.4);
  transition: border-color var(--t-fast) var(--ease), color var(--t-fast) var(--ease);
}

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

/* ---------- 图片容器 ---------- */
.page-about .ab-figure {
  margin: 0 0 26px;
  border: 1px solid var(--line);
  border-radius: 4px;
  background: var(--panel);
  overflow: hidden;
}

.page-about .ab-figure img {
  display: block;
  width: 100%;
  height: auto;
  aspect-ratio: 14 / 9;
  object-fit: cover;
}

.page-about .ab-figure--tight {
  margin: 0;
}

.page-about .ab-figcaption {
  display: block;
  padding: 10px 14px;
  border-top: 1px solid var(--line);
  font-size: 12px;
  letter-spacing: 0.04em;
  color: var(--index);
}

/* ---------- 时间轴 ---------- */
.page-about .ab-filter {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
  margin: 22px 0 26px;
}

.page-about .ab-filter .chip {
  appearance: none;
  -webkit-appearance: none;
  padding: 7px 14px;
  border: 1px solid var(--line);
  border-radius: 3px;
  background: transparent;
  font-family: var(--font-body);
  font-size: 13px;
  color: var(--index);
  cursor: pointer;
  transition: color var(--t-fast) var(--ease), border-color var(--t-fast) var(--ease), background var(--t-fast) var(--ease);
}

.page-about .ab-filter .chip:hover {
  color: var(--silver);
  border-color: var(--cyan);
}

.page-about .ab-filter .chip[aria-pressed="true"] {
  color: var(--void);
  background: var(--cyan);
  border-color: var(--cyan);
}

.page-about .ab-timeline {
  position: relative;
  margin: 0;
  padding: 0 0 0 26px;
  list-style: none;
}

.page-about .ab-timeline::before {
  content: "";
  position: absolute;
  left: 6px;
  top: 8px;
  bottom: 8px;
  width: 1px;
  background-image: linear-gradient(180deg, var(--cyan) 0%, var(--lava) 100%);
  opacity: 0.55;
}

.page-about .tl-node {
  position: relative;
  margin-bottom: 12px;
}

.page-about .tl-node::before {
  content: "";
  position: absolute;
  left: -26px;
  top: 21px;
  width: 13px;
  height: 13px;
  border-radius: 50%;
  border: 1px solid var(--cyan);
  background: var(--void);
}

.page-about .tl-node:nth-child(n + 5)::before {
  border-color: var(--lava);
}

.page-about .tl-detail {
  border: 1px solid var(--line);
  border-radius: 4px;
  background: var(--panel);
  transition: border-color var(--t) var(--ease), background var(--t) var(--ease);
}

.page-about .tl-detail[open] {
  border-color: rgba(43, 233, 224, 0.38);
  background: var(--panel-2);
}

.page-about .tl-detail > summary {
  display: flex;
  align-items: center;
  gap: 12px;
  padding: 15px 16px;
  cursor: pointer;
  list-style: none;
}

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

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

.page-about .tl-season {
  flex: none;
  width: 30px;
  font-size: 13px;
  letter-spacing: 0.06em;
  color: var(--cyan);
}

.page-about .tl-title {
  flex: 1 1 auto;
  min-width: 0;
  font-size: 15.5px;
  font-weight: 500;
  line-height: 1.55;
  color: var(--silver);
}

.page-about .tl-arrow {
  position: relative;
  flex: none;
  width: 13px;
  height: 13px;
}

.page-about .tl-arrow::before,
.page-about .tl-arrow::after {
  content: "";
  position: absolute;
  background: var(--index);
  transition: transform var(--t) var(--ease), background var(--t) var(--ease);
}

.page-about .tl-arrow::before {
  left: 0;
  top: 6px;
  width: 13px;
  height: 1px;
}

.page-about .tl-arrow::after {
  left: 6px;
  top: 0;
  width: 1px;
  height: 13px;
}

.page-about .tl-detail[open] .tl-arrow::after {
  transform: scaleY(0);
}

.page-about .tl-detail[open] .tl-arrow::before {
  background: var(--cyan);
}

.page-about .tl-panel {
  padding: 14px 16px 18px;
  border-top: 1px solid var(--line);
}

.page-about .tl-panel p {
  margin: 0;
  max-width: 62ch;
  font-size: 14.5px;
  line-height: 1.85;
  color: var(--silver);
}

.page-about .tl-figure {
  margin: 16px 0 0;
  max-width: 400px;
}

.page-about .tl-figure img {
  display: block;
  width: 100%;
  height: auto;
  border: 1px solid var(--line);
  border-radius: 3px;
}

.page-about .tl-figure figcaption {
  margin-top: 8px;
  font-size: 12px;
  color: var(--index);
}

/* ---------- 团队 ---------- */
.page-about .ab-teams {
  display: grid;
  grid-template-columns: 1fr;
  gap: 14px;
  margin: 26px 0 0;
}

.page-about .ab-team {
  position: relative;
  padding: 20px 18px 22px;
  border: 1px solid var(--line);
  border-radius: 4px;
  background: var(--panel);
  box-shadow: 0 18px 40px -34px rgba(0, 0, 0, 0.95);
}

.page-about .ab-team::before {
  content: "";
  position: absolute;
  left: 18px;
  top: 0;
  width: 34px;
  height: 2px;
  background: var(--ab-grad);
}

.page-about .ab-team-tag {
  font-size: 11px;
  letter-spacing: 0.14em;
  color: var(--lava);
}

.page-about .ab-team h3 {
  margin: 14px 0 8px;
  font-family: var(--font-display);
  font-weight: 400;
  font-size: 20px;
  letter-spacing: 0.01em;
  color: #fff;
}

.page-about .ab-team p {
  margin: 0;
  font-size: 14px;
  line-height: 1.8;
  color: var(--silver);
}

/* ---------- 内容资产 ---------- */
.page-about .ab-board {
  display: grid;
  grid-template-columns: 1fr;
  gap: 26px;
  margin: 22px 0 0;
}

.page-about .ab-assets {
  display: grid;
  grid-template-columns: 1fr;
  gap: 1px;
  margin: 0 0 22px;
  border: 1px solid var(--line);
  border-radius: 4px;
  background: var(--line);
  overflow: hidden;
}

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

.page-about .ab-asset-num {
  display: block;
  font-size: clamp(34px, 7vw, 50px);
  line-height: 1;
  font-weight: 500;
  color: var(--cyan);
}

.page-about .ab-asset:nth-child(2) .ab-asset-num {
  color: var(--lava);
}

.page-about .ab-asset-label {
  display: block;
  margin-top: 10px;
  font-size: 13px;
  letter-spacing: 0.04em;
  color: var(--silver);
}

.page-about .ab-asset-note {
  display: block;
  margin-top: 8px;
  font-size: 13px;
  line-height: 1.7;
  color: var(--index);
}

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

.page-about .ab-tags li {
  padding: 6px 12px;
  border: 1px solid var(--line);
  border-radius: 3px;
  font-size: 12.5px;
  color: var(--index);
}

/* ---------- 更新节奏 ---------- */
.page-about .ab-steps {
  margin: 20px 0 0;
  padding: 0;
  list-style: none;
  counter-reset: ab-step;
  display: grid;
  gap: 1px;
  border-block: 1px solid var(--line);
  background: var(--line);
}

.page-about .ab-step {
  position: relative;
  counter-increment: ab-step;
  padding: 18px 0 18px 48px;
  background: var(--void);
}

.page-about .ab-step::before {
  content: counter(ab-step, decimal-leading-zero);
  position: absolute;
  left: 0;
  top: 20px;
  font-family: var(--font-mono);
  font-size: 13px;
  letter-spacing: 0.06em;
  color: var(--lava);
}

.page-about .ab-step h3 {
  margin: 0 0 7px;
  font-size: 16px;
  font-weight: 500;
  color: #fff;
}

.page-about .ab-step p {
  margin: 0;
  max-width: 64ch;
  font-size: 14.5px;
  line-height: 1.8;
  color: var(--silver);
}

/* ---------- 社群协作 ---------- */
.page-about .ab-community {
  display: grid;
  grid-template-columns: 1fr;
  gap: 1px;
  margin: 22px 0 0;
  border: 1px solid var(--line);
  border-radius: 4px;
  background: var(--line);
  overflow: hidden;
}

.page-about .ab-comm-item {
  background: var(--panel);
  padding: 20px 18px 22px;
}

.page-about .ab-comm-item h3 {
  margin: 0 0 9px;
  font-family: var(--font-display);
  font-weight: 400;
  font-size: 19px;
  color: #fff;
}

.page-about .ab-comm-item p {
  margin: 0;
  font-size: 14px;
  line-height: 1.8;
  color: var(--silver);
}

/* ---------- 结尾 ---------- */
.page-about .ab-section--end {
  padding-top: 64px;
}

.page-about .ab-cta {
  position: relative;
  padding: 32px 22px 30px;
  border: 1px solid var(--line);
  border-radius: 4px;
  background: var(--panel);
  overflow: hidden;
}

.page-about .ab-cta::before {
  content: "";
  position: absolute;
  left: 0;
  top: 0;
  width: 100%;
  height: 2px;
  background: var(--ab-grad);
  opacity: 0.85;
}

.page-about .ab-cta-eyebrow {
  margin: 0;
  font-size: 11px;
  letter-spacing: 0.18em;
  text-transform: uppercase;
  color: var(--lava);
}

.page-about .ab-cta-title {
  margin: 14px 0 12px;
  font-family: var(--font-display);
  font-weight: 300;
  font-size: clamp(25px, 4.6vw, 36px);
  line-height: 1.2;
  color: #fff;
}

.page-about .ab-cta-text {
  margin: 0 0 22px;
  max-width: 60ch;
  font-size: 15px;
  line-height: 1.8;
  color: var(--silver);
}

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

/* ---------- 动效 ---------- */
.page-about [data-reveal] {
  opacity: 0;
  transform: translateY(12px);
  transition: opacity var(--t-panel) var(--ease), transform var(--t-panel) var(--ease);
}

.page-about [data-reveal].is-visible {
  opacity: 1;
  transform: none;
}

/* ---------- 响应式 ---------- */
@media (min-width: 640px) {
  .page-about .ab-hero-meta {
    grid-template-columns: repeat(3, 1fr);
  }

  .page-about .ab-assets {
    grid-template-columns: repeat(3, 1fr);
  }

  .page-about .ab-community {
    grid-template-columns: repeat(2, 1fr);
  }

  .page-about .ab-cta {
    padding: 40px 34px 36px;
  }
}

@media (min-width: 780px) {
  .page-about .ab-teams {
    grid-template-columns: repeat(3, 1fr);
  }

  .page-about .ab-community {
    grid-template-columns: repeat(3, 1fr);
  }
}

@media (min-width: 900px) {
  .page-about .container {
    padding-inline: 40px;
  }

  .page-about .ab-split {
    grid-template-columns: 128px minmax(0, 1fr);
    gap: 42px;
  }

  .page-about .ab-rail {
    flex-direction: column;
    align-items: flex-start;
    gap: 10px;
    padding: 0 0 0 16px;
    border-bottom: 0;
    border-left: 1px solid var(--line);
  }

  .page-about .ab-index {
    font-size: 36px;
  }

  .page-about .ab-board {
    grid-template-columns: minmax(0, 1.06fr) minmax(0, 0.94fr);
    gap: 38px;
    align-items: start;
  }

  .page-about .ab-assets {
    grid-template-columns: 1fr;
  }

  .page-about .ab-figure--offset {
    margin-inline-start: -46px;
  }

  .page-about .ab-cta {
    padding: 46px 44px 42px;
  }
}

@media (min-width: 1024px) {
  .page-about .about-toc {
    top: 0;
  }

  .page-about .ab-section {
    padding-block: 72px 0;
  }
}

@media (prefers-reduced-motion: reduce) {
  .page-about [data-reveal] {
    opacity: 1;
    transform: none;
    transition: none;
  }

  .page-about .ab-timeline::before {
    background-image: none;
    background-color: var(--line);
  }
}