.page-about {
  --about-rail-w: 92px;
  --about-body-gap: 40px;
  --about-orb-blur: 90px;
}

/* ---------- 首屏 ---------- */

.page-about .about-hero {
  position: relative;
  overflow: hidden;
  padding: clamp(20px, 4vw, 44px) 0 clamp(48px, 7vw, 84px);
}

.page-about .about-hero .glow-orb--magenta {
  top: -180px;
  left: -140px;
  width: 480px;
  height: 480px;
  filter: blur(var(--about-orb-blur));
  opacity: .34;
}

.page-about .about-hero .glow-orb--cyan {
  top: 30px;
  right: -160px;
  width: 420px;
  height: 420px;
  filter: blur(var(--about-orb-blur));
  opacity: .26;
}

.page-about .about-hero .glow-orb--gold {
  bottom: -260px;
  left: 42%;
  width: 320px;
  height: 320px;
  filter: blur(var(--about-orb-blur));
  opacity: .18;
}

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

.page-about .about-hero .breadcrumbs {
  margin-bottom: var(--sp-6);
}

.page-about .about-hero-title {
  font-family: var(--font-display);
  font-size: var(--fs-display-l);
  line-height: 1.06;
  font-weight: 800;
  letter-spacing: -0.02em;
  color: var(--ink);
  max-width: 18ch;
  margin: var(--sp-3) 0 0;
  text-shadow: 0 0 16px rgba(255, 45, 138, .22), 0 0 30px rgba(35, 213, 232, .12);
}

.page-about .about-hero-lead {
  max-width: 62ch;
  margin: var(--sp-5) 0 0;
  font-size: 16px;
  line-height: 1.75;
  color: var(--muted);
}

.page-about .about-metrics {
  margin-top: var(--sp-7);
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 1px;
  background: var(--line);
  border: 1px solid var(--line);
  border-radius: var(--r-card);
  overflow: hidden;
}

.page-about .about-metric {
  background: var(--surface);
  padding: var(--sp-5) var(--sp-4);
  display: flex;
  flex-direction: column;
  gap: 6px;
}

.page-about .about-metric-num {
  font-size: clamp(26px, 4vw, 40px);
  font-weight: 700;
  line-height: 1;
  letter-spacing: -0.01em;
}

.page-about .about-metric:nth-child(1) .about-metric-num { color: var(--magenta); }
.page-about .about-metric:nth-child(2) .about-metric-num { color: var(--cyan); }
.page-about .about-metric:nth-child(3) .about-metric-num { color: var(--gold); }
.page-about .about-metric:nth-child(4) .about-metric-num { color: var(--ink); }

.page-about .about-metric-label {
  font-size: 13px;
  line-height: 1.5;
  color: var(--muted);
}

/* ---------- 分屏骨架 ---------- */

.page-about .about-body {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: var(--about-body-gap);
}

.page-about .about-sections {
  min-width: 0;
  display: flex;
  flex-direction: column;
}

/* ---------- 左侧编号索引 ---------- */

.page-about .about-rail {
  display: flex;
  gap: var(--sp-2);
  overflow-x: auto;
  padding-bottom: var(--sp-2);
  scrollbar-width: none;
}

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

.page-about .about-rail .index-link {
  flex: 0 0 auto;
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 8px 14px;
  border-radius: var(--r-pill);
  border: 1px solid var(--line);
  background: var(--surface);
  color: var(--muted);
  font-size: 13px;
  text-decoration: none;
  white-space: nowrap;
  transition: color var(--dur) var(--ease), border-color var(--dur) var(--ease), background var(--dur) var(--ease);
}

.page-about .about-rail .index-num {
  font-size: 12px;
  letter-spacing: .06em;
  color: var(--cyan);
}

.page-about .about-rail .index-link:hover {
  color: var(--ink);
  border-color: rgba(255, 45, 138, .5);
}

.page-about .about-rail .index-link[aria-current="true"] {
  color: var(--ink);
  border-color: transparent;
  background: linear-gradient(120deg, rgba(255, 45, 138, .9), rgba(106, 43, 255, .85));
}

.page-about .about-rail .index-link[aria-current="true"] .index-num {
  color: rgba(8, 9, 15, .82);
}

/* ---------- 章节通用 ---------- */

.page-about .about-section {
  position: relative;
}

.page-about .section-num {
  display: block;
  font-family: var(--font-mono);
  font-size: clamp(26px, 3.6vw, 38px);
  font-weight: 700;
  line-height: 1;
  letter-spacing: .04em;
  color: rgba(255, 45, 138, .16);
  -webkit-text-stroke: 1px rgba(255, 45, 138, .5);
  margin-bottom: var(--sp-3);
}

.page-about .section-title {
  font-family: var(--font-display);
  font-size: clamp(22px, 2.8vw, 32px);
  line-height: 1.2;
  font-weight: 700;
  letter-spacing: -0.02em;
  color: var(--ink);
  max-width: 22ch;
  margin: 0;
}

.page-about .section-lead {
  max-width: 56ch;
  margin: var(--sp-4) 0 0;
  font-size: 15px;
  line-height: 1.75;
  color: var(--muted);
}

.page-about .about-copy {
  max-width: 66ch;
  margin-top: var(--sp-5);
}

.page-about .about-copy p {
  margin: 0 0 var(--sp-4);
  font-size: 16px;
  line-height: 1.8;
  color: var(--muted);
}

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

.page-about .about-copy a,
.page-about .about-coverage-text a,
.page-about .about-cta-lead a {
  color: var(--cyan);
  text-decoration: none;
  border-bottom: 1px solid rgba(35, 213, 232, .45);
  transition: border-color var(--dur) var(--ease), color var(--dur) var(--ease);
}

.page-about .about-copy a:hover,
.page-about .about-coverage-text a:hover,
.page-about .about-cta-lead a:hover {
  color: var(--ink);
  border-bottom-color: var(--magenta);
}

/* ---------- 001 起点 ---------- */

.page-about .about-facts {
  list-style: none;
  margin: var(--sp-6) 0 0;
  padding: 0;
  display: flex;
  flex-wrap: wrap;
  gap: var(--sp-4) var(--sp-6);
}

.page-about .about-facts li {
  display: flex;
  align-items: baseline;
  gap: 10px;
  font-size: 14px;
  color: var(--muted);
  padding-left: var(--sp-3);
  border-left: 2px solid var(--line);
}

.page-about .about-facts .mono {
  font-size: 17px;
  font-weight: 700;
  color: var(--gold);
}

/* ---------- 002 版本时间轴 ---------- */

.page-about .about-versions {
  margin-top: var(--sp-6);
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: var(--sp-6);
}

.page-about .about-versions-figure {
  border-radius: var(--r-frame);
  overflow: hidden;
  aspect-ratio: 16 / 10;
}

.page-about .about-versions-figure img,
.page-about .about-principles-figure img,
.page-about .about-coverage-figure img {
  width: 100%;
  height: 100%;
  display: block;
  object-fit: cover;
}

.page-about .about-timeline {
  display: grid;
  gap: var(--sp-3);
}

.page-about .about-timeline .accordion-item {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 0;
  background: var(--surface);
  border: 1px solid var(--line);
  border-radius: var(--r-card);
  padding: var(--sp-4) var(--sp-4) var(--sp-4);
  transition: border-color var(--dur) var(--ease), transform var(--dur) var(--ease);
}

.page-about .about-timeline .accordion-item:hover {
  border-color: rgba(35, 213, 232, .42);
  transform: translateX(3px);
}

.page-about .about-timeline .accordion-item.is-current {
  border-color: rgba(255, 45, 138, .45);
  background: linear-gradient(135deg, rgba(255, 45, 138, .1), rgba(18, 20, 32, .96) 46%);
}

.page-about .about-node-year {
  font-size: 13px;
  letter-spacing: .1em;
  color: var(--cyan);
  margin-bottom: var(--sp-2);
}

.page-about .about-node-head {
  margin: 0;
}

.page-about .about-node-trigger {
  width: 100%;
  display: flex;
  align-items: center;
  gap: var(--sp-3);
  background: none;
  border: 0;
  padding: 0;
  cursor: pointer;
  text-align: left;
  color: var(--ink);
  font-family: var(--font-display);
  font-size: 17px;
  font-weight: 700;
  letter-spacing: -0.01em;
}

.page-about .about-ver-tag {
  flex: 0 0 auto;
  font-size: 12px;
  letter-spacing: .08em;
  padding: 4px 10px;
  border-radius: var(--r-pill);
  color: var(--magenta);
  background: rgba(255, 45, 138, .12);
  border: 1px solid rgba(255, 45, 138, .32);
}

.page-about .about-ver-name {
  flex: 1 1 auto;
  min-width: 0;
}

.page-about .about-node-trigger::after {
  content: "+";
  flex: 0 0 auto;
  font-family: var(--font-mono);
  font-size: 18px;
  line-height: 1;
  color: var(--cyan);
}

.page-about .about-node-trigger[aria-expanded="true"]::after {
  content: "–";
  color: var(--magenta);
}

.page-about .about-timeline .accordion-panel {
  margin-top: var(--sp-3);
  padding-left: calc(12px + var(--sp-3));
  border-left: 1px solid var(--line);
}

.page-about .about-timeline .accordion-panel p {
  margin: 0;
  font-size: 15px;
  line-height: 1.75;
  color: var(--muted);
}

/* ---------- 003 团队 ---------- */

.page-about .about-team-grid {
  margin-top: var(--sp-6);
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: var(--sp-4);
}

.page-about .about-team-card {
  display: flex;
  flex-direction: column;
  gap: var(--sp-2);
  padding: var(--sp-6) var(--sp-5) var(--sp-5);
  border-radius: var(--r-card);
  border: 1px solid var(--line);
  background: var(--surface);
}

.page-about .about-team-count {
  font-size: clamp(38px, 6vw, 56px);
  font-weight: 700;
  line-height: 1;
  color: transparent;
  -webkit-text-stroke: 1.4px rgba(35, 213, 232, .78);
  margin-bottom: var(--sp-2);
}

.page-about .about-team-card:nth-child(2) .about-team-count {
  -webkit-text-stroke-color: rgba(255, 45, 138, .78);
}

.page-about .about-team-card:nth-child(3) .about-team-count {
  -webkit-text-stroke-color: rgba(255, 196, 107, .8);
}

.page-about .about-team-card .card-title {
  font-family: var(--font-display);
  font-size: 18px;
  font-weight: 700;
  color: var(--ink);
  margin: 0;
}

.page-about .about-team-card p {
  margin: 0;
  font-size: 15px;
  line-height: 1.75;
  color: var(--muted);
}

.page-about .about-team-card .card-note {
  margin-top: var(--sp-3);
  padding-top: var(--sp-3);
  border-top: 1px solid var(--line);
  font-size: 13px;
  color: var(--cyan);
}

/* ---------- 004 两条原则 ---------- */

.page-about .about-principles {
  background: linear-gradient(150deg, rgba(27, 30, 46, .95), rgba(18, 20, 32, .95));
  border: 1px solid var(--line);
  border-radius: var(--r-frame);
  padding: clamp(28px, 4.5vw, 56px);
  position: relative;
  overflow: hidden;
}

.page-about .about-principles::before {
  content: "";
  position: absolute;
  inset: -1px;
  border-radius: inherit;
  background: var(--grad-hair);
  height: 2px;
  opacity: .8;
  pointer-events: none;
}

.page-about .about-principles-grid {
  position: relative;
  z-index: 1;
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: var(--sp-6);
}

.page-about .about-principles-num {
  -webkit-text-stroke-color: rgba(35, 213, 232, .55);
  color: rgba(35, 213, 232, .14);
}

.page-about .about-principles-figure {
  border-radius: var(--r-frame);
  overflow: hidden;
  aspect-ratio: 4 / 3;
  order: -1;
}

.page-about .about-principle {
  margin-top: var(--sp-6);
  padding-top: var(--sp-5);
  border-top: 1px solid var(--line);
}

.page-about .about-principle-key {
  display: inline-block;
  font-size: 12px;
  letter-spacing: .12em;
  padding: 4px 12px;
  border-radius: var(--r-pill);
  color: var(--night);
  background: var(--grad-magenta);
  margin-bottom: var(--sp-3);
}

.page-about .about-principle h3 {
  margin: 0 0 var(--sp-3);
  font-family: var(--font-display);
  font-size: 19px;
  font-weight: 700;
  line-height: 1.35;
  color: var(--ink);
}

.page-about .about-principle p {
  margin: 0;
  font-size: 15px;
  line-height: 1.8;
  color: var(--muted);
  max-width: 58ch;
}

/* ---------- 005 覆盖 ---------- */

.page-about .about-coverage {
  margin-top: var(--sp-6);
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: var(--sp-5);
}

.page-about .about-coverage-text p {
  margin: 0 0 var(--sp-4);
  font-size: 16px;
  line-height: 1.8;
  color: var(--muted);
  max-width: 58ch;
}

.page-about .about-coverage-stats {
  list-style: none;
  margin: var(--sp-5) 0 0;
  padding: 0;
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 1px;
  background: var(--line);
  border: 1px solid var(--line);
  border-radius: var(--r-card);
  overflow: hidden;
}

.page-about .about-coverage-stats li {
  background: var(--surface);
  padding: var(--sp-4) var(--sp-5);
  display: flex;
  align-items: baseline;
  gap: var(--sp-4);
}

.page-about .about-stat-num {
  flex: 0 0 auto;
  font-size: clamp(20px, 2.4vw, 26px);
  font-weight: 700;
  color: var(--gold);
}

.page-about .about-stat-label {
  font-size: 14px;
  line-height: 1.5;
  color: var(--muted);
}

.page-about .about-coverage-figure {
  border-radius: var(--r-frame);
  overflow: hidden;
  aspect-ratio: 16 / 9;
}

/* ---------- 006 三件事 ---------- */

.page-about .about-next {
  list-style: none;
  margin: var(--sp-6) 0 0;
  padding: 0;
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: var(--sp-4);
}

.page-about .about-next li {
  position: relative;
  background: linear-gradient(180deg, rgba(27, 30, 46, .92), rgba(18, 20, 32, .92));
  border: 1px solid var(--line);
  border-radius: var(--r-card);
  padding: var(--sp-6) var(--sp-5) var(--sp-5);
  transition: transform var(--dur) var(--ease), border-color var(--dur) var(--ease);
}

.page-about .about-next li:hover {
  transform: translateY(-4px);
  border-color: rgba(255, 196, 107, .45);
}

.page-about .about-next-num {
  display: inline-block;
  font-size: 12px;
  letter-spacing: .16em;
  padding: 4px 12px;
  border-radius: var(--r-pill);
  color: var(--gold);
  background: rgba(255, 196, 107, .1);
  border: 1px solid rgba(255, 196, 107, .3);
  margin-bottom: var(--sp-4);
}

.page-about .about-next h3 {
  margin: 0 0 var(--sp-3);
  font-family: var(--font-display);
  font-size: 18px;
  font-weight: 700;
  line-height: 1.35;
  color: var(--ink);
}

.page-about .about-next p {
  margin: 0;
  font-size: 15px;
  line-height: 1.78;
  color: var(--muted);
}

/* ---------- 收束 ---------- */

.page-about .about-cta {
  margin-top: clamp(56px, 8vw, 104px);
}

.page-about .about-cta-inner {
  position: relative;
  overflow: hidden;
  border-radius: var(--r-frame);
  border: 1px solid var(--line);
  background: linear-gradient(130deg, rgba(255, 45, 138, .14), rgba(106, 43, 255, .1) 48%, rgba(35, 213, 232, .12));
  padding: clamp(32px, 5vw, 56px);
}

.page-about .about-cta-title {
  max-width: 24ch;
}

.page-about .about-cta-lead {
  max-width: 56ch;
  margin: var(--sp-4) 0 0;
  font-size: 15px;
  line-height: 1.8;
  color: var(--muted);
}

.page-about .about-cta-actions {
  margin-top: var(--sp-6);
  display: flex;
  flex-wrap: wrap;
  gap: var(--sp-3);
}

/* ---------- 响应式 ---------- */

@media (min-width: 640px) {
  .page-about .about-metrics {
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }

  .page-about .about-timeline .accordion-item {
    grid-template-columns: 72px minmax(0, 1fr);
    padding: var(--sp-5);
    column-gap: var(--sp-4);
  }

  .page-about .about-node-year {
    grid-column: 1;
    grid-row: 1 / span 2;
    padding-top: 6px;
    margin-bottom: 0;
  }

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

  .page-about .about-timeline .accordion-panel {
    grid-column: 2;
    grid-row: 2;
  }

  .page-about .about-principles-figure {
    order: 0;
  }

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

  .page-about .about-coverage-stats li {
    flex-direction: column;
    align-items: flex-start;
    gap: 6px;
  }
}

@media (min-width: 768px) {
  .page-about .about-metrics {
    grid-template-columns: repeat(4, minmax(0, 1fr));
  }

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

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

@media (min-width: 960px) {
  .page-about .about-versions {
    grid-template-columns: minmax(0, 4fr) minmax(0, 8fr);
    gap: var(--sp-7);
    align-items: start;
  }

  .page-about .about-versions-figure {
    position: sticky;
    top: 132px;
    aspect-ratio: 4 / 5;
  }

  .page-about .about-principles-grid {
    grid-template-columns: minmax(0, 7fr) minmax(0, 5fr);
    gap: var(--sp-7);
    align-items: start;
  }

  .page-about .about-principles-figure {
    aspect-ratio: 4 / 5;
    position: sticky;
    top: 132px;
  }

  .page-about .about-coverage {
    grid-template-columns: minmax(0, 5fr) minmax(0, 7fr);
    gap: var(--sp-7);
    align-items: center;
  }
}

@media (min-width: 1024px) {
  .page-about .about-body {
    grid-template-columns: var(--about-rail-w) minmax(0, 1fr);
    gap: clamp(32px, 5vw, 64px);
    align-items: start;
  }

  .page-about .about-rail {
    position: sticky;
    top: 132px;
    flex-direction: column;
    align-items: stretch;
    gap: var(--sp-3);
    overflow: visible;
    padding: 0 0 0 var(--sp-4);
    border-left: 1px solid var(--line);
  }

  .page-about .about-rail .index-link {
    justify-content: flex-start;
    border-color: transparent;
    background: transparent;
    padding: 6px 10px;
  }

  .page-about .about-rail .index-link:hover {
    background: var(--surface);
    border-color: var(--line);
  }

  .page-about .about-rail .index-link[aria-current="true"] {
    border-color: transparent;
  }
}

@media (prefers-reduced-motion: reduce) {
  .page-about .about-timeline .accordion-item,
  .page-about .about-next li,
  .page-about .about-rail .index-link {
    transition: none;
  }

  .page-about .about-timeline .accordion-item:hover,
  .page-about .about-next li:hover {
    transform: none;
  }
}