.page-about {
  --about-gap: clamp(20px, 3.4vw, 34px);
  --about-sec: clamp(42px, 7vw, 78px);
  --about-indigo: #8b7cf6;
  --about-blue: #3fa9f5;
  display: block;
  overflow-x: clip;
  background: var(--ink);
  color: var(--text);
  font-family: var(--font-sans);
}

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

/* ---------- 首屏 ---------- */
.page-about .about-hero {
  position: relative;
  padding: clamp(20px, 3.4vw, 36px) 0 clamp(30px, 5vw, 56px);
  border-bottom: 1px solid var(--line);
  background:
    radial-gradient(120% 88% at 6% -12%, rgba(37, 227, 212, 0.13), transparent 60%),
    radial-gradient(90% 76% at 104% 6%, rgba(255, 62, 156, 0.1), transparent 64%),
    var(--ink);
}

.page-about .about-hero .crumbs {
  margin-bottom: clamp(18px, 3vw, 30px);
}

.page-about .about-hero__top {
  display: grid;
  gap: clamp(20px, 3.6vw, 40px);
  align-items: end;
}

.page-about .about-kicker {
  margin: 0 0 14px;
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.2em;
  color: var(--cyan);
}

.page-about .about-kicker::before {
  content: "";
  display: inline-block;
  width: 22px;
  height: 2px;
  margin-right: 10px;
  vertical-align: 4px;
  background: linear-gradient(90deg, var(--cyan), var(--magenta));
}

.page-about .about-hero h1 {
  margin: 0;
  max-width: 22ch;
  font-size: clamp(30px, 5.6vw, 56px);
  font-weight: 800;
  line-height: 1.15;
  letter-spacing: 0.02em;
}

.page-about .about-lede {
  margin: clamp(16px, 2.4vw, 22px) 0 0;
  max-width: 62ch;
  font-size: clamp(16px, 1.5vw, 18px);
  line-height: 1.75;
  color: var(--text);
  opacity: 0.88;
}

.page-about .about-stats {
  list-style: none;
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 1px;
  margin: 0;
  padding: 0;
  border: 1px solid var(--line);
  border-radius: var(--radius);
  background: var(--line);
  overflow: hidden;
}

.page-about .about-stat {
  background: var(--raise);
  padding: 14px 16px;
}

.page-about .about-stat__num {
  display: block;
  font-family: var(--font-mono);
  font-size: clamp(20px, 2.6vw, 28px);
  font-weight: 700;
  letter-spacing: 0.02em;
  color: var(--cyan);
}

.page-about .about-stat:nth-child(2) .about-stat__num {
  color: var(--gold);
}

.page-about .about-stat:nth-child(3) .about-stat__num {
  color: var(--magenta);
}

.page-about .about-stat:nth-child(4) .about-stat__num {
  color: var(--text);
}

.page-about .about-stat__label {
  display: block;
  margin-top: 6px;
  font-size: 13px;
  line-height: 1.5;
  color: var(--dim);
}

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

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

.page-about .about-figure--wide {
  margin-top: clamp(24px, 4vw, 44px);
}

.page-about .about-figure--wide img {
  aspect-ratio: 16 / 9;
}

.page-about .about-figure--std img {
  aspect-ratio: 3 / 2;
}

.page-about .about-figure--tall img {
  aspect-ratio: 1 / 1;
}

.page-about .about-figure__label {
  position: absolute;
  left: 0;
  bottom: 0;
  padding: 8px 14px;
  border-top: 1px solid var(--line);
  border-right: 1px solid var(--line);
  background: rgba(11, 14, 36, 0.86);
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: 0.16em;
  color: var(--cyan);
}

/* ---------- 骨架 ---------- */
.page-about .about-shell {
  display: grid;
  gap: clamp(24px, 4vw, 44px);
  padding-top: clamp(34px, 6vw, 68px);
  padding-bottom: clamp(48px, 8vw, 96px);
}

.page-about .about-main {
  display: grid;
  gap: var(--about-sec);
  min-width: 0;
}

.page-about .about-section {
  scroll-margin-top: calc(var(--header-h) + 24px);
  min-width: 0;
}

.page-about .about-sec--index { --accent: var(--cyan); }
.page-about .about-sec--review { --accent: var(--magenta); }
.page-about .about-sec--record { --accent: var(--about-indigo); }
.page-about .about-sec--gold { --accent: var(--gold); }
.page-about .about-sec--net { --accent: var(--about-blue); }

.page-about .about-section__head {
  display: grid;
  grid-template-columns: auto minmax(0, 1fr);
  gap: 10px 14px;
  align-items: baseline;
  padding-bottom: 16px;
  margin-bottom: clamp(20px, 3vw, 32px);
  border-bottom: 1px solid var(--line);
}

.page-about .about-section__num {
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.2em;
  color: var(--accent, var(--cyan));
}

.page-about .about-section__title {
  margin: 0;
  font-size: clamp(21px, 3vw, 32px);
  font-weight: 800;
  line-height: 1.2;
  letter-spacing: 0.02em;
}

.page-about .about-section__intro {
  grid-column: 1 / -1;
  margin: 0;
  max-width: 66ch;
  font-size: 15.5px;
  line-height: 1.75;
  color: var(--dim);
}

.page-about .about-para {
  margin: 0;
  max-width: 62ch;
  font-size: 15px;
  line-height: 1.78;
  color: var(--dim);
}

/* ---------- 01 三类麻烦 ---------- */
.page-about .doing-list {
  display: grid;
  gap: 14px;
}

.page-about .doing-item {
  padding: 16px 18px;
  border: 1px solid var(--line);
  border-left: 3px solid var(--accent, var(--cyan));
  border-radius: var(--radius);
  background: var(--raise);
}

.page-about .doing-item h3 {
  margin: 0 0 8px;
  font-size: 17px;
  font-weight: 700;
  letter-spacing: 0.01em;
}

.page-about .doing-item p {
  margin: 0;
  font-size: 15px;
  line-height: 1.75;
  color: var(--dim);
}

/* ---------- 02 版本阶段带 ---------- */
.page-about .stage-band {
  position: relative;
  display: grid;
  gap: 16px;
}

.page-about .stage-band::before {
  content: "";
  position: absolute;
  left: 7px;
  top: 10px;
  bottom: 10px;
  width: 2px;
  opacity: 0.85;
  background: linear-gradient(180deg, var(--cyan) 0%, var(--about-blue) 34%, var(--about-indigo) 70%, var(--magenta) 100%);
}

.page-about .stage-node {
  position: relative;
  margin-left: 30px;
  border: 1px solid var(--line);
  border-radius: var(--radius);
  background: var(--raise);
  transition: border-color 0.18s ease, transform 0.18s ease;
}

.page-about .stage-node::before {
  content: "";
  position: absolute;
  left: -28px;
  top: 20px;
  width: 10px;
  height: 10px;
  border-radius: 2px;
  background: var(--node, var(--cyan));
  box-shadow: 0 0 0 4px rgba(11, 14, 36, 0.92);
}

.page-about .stage-node:nth-child(1) { --node: var(--cyan); background: rgba(8, 48, 47, 0.62); }
.page-about .stage-node:nth-child(2) { --node: var(--cyan); background: rgba(8, 48, 47, 0.46); }
.page-about .stage-node:nth-child(3) { --node: var(--about-blue); background: rgba(19, 26, 61, 0.92); }
.page-about .stage-node:nth-child(4) { --node: var(--about-indigo); background: rgba(26, 20, 64, 0.86); }
.page-about .stage-node:nth-child(5) { --node: var(--magenta); background: rgba(46, 15, 38, 0.72); }
.page-about .stage-node:nth-child(6) { --node: var(--gold); background: rgba(46, 15, 38, 0.5); }

.page-about .stage-node:hover {
  transform: translateY(-2px);
  border-color: rgba(237, 240, 250, 0.22);
}

.page-about .stage-node > summary {
  display: grid;
  grid-template-columns: auto minmax(0, 1fr) auto;
  align-items: center;
  gap: 10px 12px;
  padding: 16px 18px;
  cursor: pointer;
  list-style: none;
}

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

.page-about .stage-node:nth-child(n + 4) > summary {
  padding-block: 20px;
}

.page-about .stage-node:nth-child(n + 5) > summary {
  padding-block: 24px;
}

.page-about .stage-node__no {
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.14em;
  color: var(--node, var(--cyan));
  white-space: nowrap;
}

.page-about .stage-node__name {
  font-size: 16.5px;
  font-weight: 700;
  line-height: 1.5;
}

.page-about .stage-node__toggle {
  position: relative;
  width: 18px;
  height: 18px;
  border: 1px solid var(--line);
  border-radius: 2px;
  flex: none;
}

.page-about .stage-node__toggle::before,
.page-about .stage-node__toggle::after {
  content: "";
  position: absolute;
  background: var(--node, var(--cyan));
  transition: transform 0.18s ease, opacity 0.18s ease;
}

.page-about .stage-node__toggle::before {
  left: 3px;
  right: 3px;
  top: 7px;
  height: 2px;
}

.page-about .stage-node__toggle::after {
  top: 3px;
  bottom: 3px;
  left: 7px;
  width: 2px;
}

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

.page-about .stage-node__body {
  padding: 0 18px 18px;
  border-top: 1px solid var(--line);
}

.page-about .stage-node__body ul {
  list-style: none;
  display: grid;
  gap: 8px;
  margin: 14px 0 0;
  padding: 0;
}

.page-about .stage-node__body li {
  position: relative;
  padding-left: 16px;
  font-size: 14.5px;
  line-height: 1.7;
  color: var(--dim);
}

.page-about .stage-node__body li::before {
  content: "";
  position: absolute;
  left: 0;
  top: 10px;
  width: 6px;
  height: 2px;
  background: var(--node, var(--cyan));
}

/* ---------- 03 团队 ---------- */
.page-about .about-split {
  display: grid;
  gap: clamp(18px, 3vw, 30px);
}

.page-about .team-grid {
  display: grid;
  gap: 14px;
  min-width: 0;
}

.page-about .team-card {
  position: relative;
  padding: 18px;
  border: 1px solid var(--line);
  border-radius: var(--radius);
  background: var(--raise-2);
  overflow: hidden;
  transition: transform 0.18s ease, border-color 0.18s ease, background 0.18s ease;
}

.page-about .team-card::after {
  content: "";
  position: absolute;
  left: 0;
  right: 0;
  bottom: 0;
  height: 2px;
  background: linear-gradient(90deg, var(--accent, var(--cyan)), var(--gold));
  transform: scaleX(0);
  transform-origin: left;
  transition: transform 0.22s ease;
}

.page-about .team-card:hover,
.page-about .team-card:focus-within {
  transform: translateY(-3px);
  border-color: rgba(37, 227, 212, 0.42);
  background: var(--raise);
}

.page-about .team-card:hover::after,
.page-about .team-card:focus-within::after {
  transform: scaleX(1);
}

.page-about .team-card__role {
  margin: 0;
  font-size: 17px;
  font-weight: 700;
}

.page-about .team-card__count {
  display: inline-block;
  margin-left: 8px;
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.1em;
  color: var(--gold);
}

.page-about .team-card__duties {
  list-style: none;
  display: grid;
  gap: 7px;
  margin: 12px 0 0;
  padding: 0;
}

.page-about .team-card__duties li {
  position: relative;
  padding-left: 14px;
  font-size: 14.5px;
  line-height: 1.7;
  color: var(--dim);
  opacity: 0.84;
  transition: opacity 0.18s ease, color 0.18s ease;
}

.page-about .team-card:hover .team-card__duties li,
.page-about .team-card:focus-within .team-card__duties li {
  opacity: 1;
  color: var(--text);
}

.page-about .team-card__duties li::before {
  content: "";
  position: absolute;
  left: 0;
  top: 9px;
  width: 5px;
  height: 5px;
  border-radius: 1px;
  background: var(--accent, var(--cyan));
  opacity: 0.75;
}

/* ---------- 04 合作生态 ---------- */
.page-about .partner-wall {
  list-style: none;
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
  margin: 0 0 clamp(18px, 3vw, 26px);
  padding: 0;
}

.page-about .partner-chip {
  padding: 8px 12px;
  border: 1px dashed var(--line);
  border-radius: var(--radius);
  background: rgba(19, 26, 61, 0.6);
  font-size: 13.5px;
  color: var(--dim);
  transition: color 0.18s ease, border-color 0.18s ease, background 0.18s ease;
}

.page-about .partner-chip:hover {
  color: var(--text);
  border-style: solid;
  border-color: var(--gold);
  background: rgba(240, 178, 60, 0.09);
}

.page-about .partner-chip--tech {
  border-style: solid;
  border-color: rgba(37, 227, 212, 0.32);
  color: var(--cyan);
  background: rgba(37, 227, 212, 0.06);
}

.page-about .partner-chip--tech:hover {
  border-color: var(--cyan);
  background: rgba(37, 227, 212, 0.12);
}

/* ---------- 05 服务网络 ---------- */
.page-about .network {
  display: grid;
  gap: 1px;
  border: 1px solid var(--line);
  border-radius: var(--radius);
  background: var(--line);
  overflow: hidden;
}

.page-about .network__item {
  padding: 18px;
  background: var(--raise);
}

.page-about .network__num {
  display: block;
  font-family: var(--font-mono);
  font-size: clamp(24px, 4vw, 34px);
  font-weight: 700;
  letter-spacing: 0.02em;
  color: var(--accent, var(--cyan));
}

.page-about .network__label {
  display: block;
  margin-top: 6px;
  font-size: 14px;
  font-weight: 700;
  color: var(--text);
}

.page-about .network__note {
  margin: 8px 0 0;
  font-size: 14px;
  line-height: 1.7;
  color: var(--dim);
}

/* ---------- 06 更新节奏 ---------- */
.page-about .rhythm-grid {
  display: grid;
  gap: 14px;
}

.page-about .rhythm-card {
  padding: 18px;
  border: 1px solid var(--line);
  border-top: 3px solid var(--accent, var(--cyan));
  border-radius: var(--radius);
  background: var(--raise);
}

.page-about .rhythm-card--gold {
  --accent: var(--gold);
}

.page-about .rhythm-card__title {
  margin: 0;
  font-size: 16.5px;
  font-weight: 700;
  letter-spacing: 0.01em;
}

.page-about .rhythm-card__list {
  list-style: none;
  display: grid;
  gap: 8px;
  margin: 12px 0 0;
  padding: 0;
}

.page-about .rhythm-card__list li {
  position: relative;
  padding-left: 16px;
  font-size: 14.5px;
  line-height: 1.7;
  color: var(--dim);
}

.page-about .rhythm-card__list li::before {
  content: "";
  position: absolute;
  left: 0;
  top: 10px;
  width: 6px;
  height: 2px;
  background: var(--accent, var(--cyan));
}

/* ---------- 行动区 ---------- */
.page-about .about-cta {
  padding: clamp(22px, 4vw, 36px);
  border: 1px solid var(--line);
  border-radius: var(--radius);
  background: linear-gradient(120deg, rgba(8, 48, 47, 0.85), rgba(26, 20, 64, 0.85) 56%, rgba(46, 15, 38, 0.7));
}

.page-about .about-cta h2 {
  margin: 0 0 10px;
  font-size: clamp(20px, 2.6vw, 28px);
  font-weight: 800;
  line-height: 1.25;
  letter-spacing: 0.02em;
}

.page-about .about-cta p {
  margin: 0;
  max-width: 62ch;
  font-size: 15.5px;
  line-height: 1.75;
  color: var(--text);
  opacity: 0.86;
}

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

/* ---------- 粘性索引 ---------- */
.page-about .about-rail {
  order: -1;
  min-width: 0;
  padding: 14px 16px;
  border: 1px solid var(--line);
  border-radius: var(--radius);
  background: var(--raise-2);
}

.page-about .about-rail__title {
  margin: 0 0 10px;
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: 0.2em;
  color: var(--dim);
}

.page-about .about-rail__list {
  list-style: none;
  display: flex;
  gap: 8px;
  margin: 0;
  padding: 0 0 2px;
  overflow-x: auto;
}

.page-about .about-rail__link {
  display: inline-block;
  padding: 6px 10px;
  border: 1px solid var(--line);
  border-radius: var(--radius);
  font-size: 13px;
  white-space: nowrap;
  color: var(--dim);
  text-decoration: none;
  transition: color 0.18s ease, border-color 0.18s ease, background 0.18s ease;
}

.page-about .about-rail__link:hover {
  color: var(--ink);
  border-color: var(--cyan);
  background: var(--cyan);
}

.page-about .about-rail__link[aria-current="true"],
.page-about .about-rail__link[aria-current="location"] {
  color: var(--cyan);
  border-color: rgba(37, 227, 212, 0.6);
  background: rgba(37, 227, 212, 0.1);
}

/* ---------- 断点 ---------- */
@media (min-width: 700px) {
  .page-about .about-stats {
    grid-template-columns: repeat(4, minmax(0, 1fr));
  }

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

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

  .page-about .stage-node {
    margin-left: 46px;
  }

  .page-about .stage-node::before {
    left: -44px;
  }

  .page-about .stage-band::before {
    left: 7px;
  }
}

@media (min-width: 1040px) {
  .page-about .about-hero__top {
    grid-template-columns: minmax(0, 1.4fr) minmax(0, 0.9fr);
  }

  .page-about .about-shell {
    grid-template-columns: minmax(0, 1fr) 224px;
    align-items: start;
  }

  .page-about .about-rail {
    order: 0;
    position: sticky;
    top: calc(var(--header-h) + 24px);
  }

  .page-about .about-rail__list {
    flex-direction: column;
    gap: 4px;
    overflow: visible;
  }

  .page-about .about-rail__link {
    display: block;
    padding: 8px 10px;
    border-color: transparent;
    border-left: 2px solid var(--line);
    border-radius: 0;
    white-space: normal;
  }

  .page-about .about-rail__link:hover {
    color: var(--cyan);
    border-color: transparent;
    border-left-color: var(--cyan);
    background: rgba(37, 227, 212, 0.08);
  }

  .page-about .about-rail__link[aria-current="true"],
  .page-about .about-rail__link[aria-current="location"] {
    border-color: transparent;
    border-left-color: var(--cyan);
  }

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

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

  .page-about .about-split {
    grid-template-columns: minmax(0, 1.15fr) minmax(0, 0.85fr);
    align-items: start;
  }

  .page-about .about-split--reverse {
    grid-template-columns: minmax(0, 0.85fr) minmax(0, 1.15fr);
  }

  .page-about .stage-node__name {
    font-size: 17.5px;
  }
}

@media (min-width: 1280px) {
  .page-about .team-grid {
    grid-template-columns: repeat(4, minmax(0, 1fr));
  }
}

@media (prefers-reduced-motion: reduce) {
  .page-about .stage-node,
  .page-about .team-card,
  .page-about .team-card::after,
  .page-about .stage-node__toggle::before,
  .page-about .stage-node__toggle::after,
  .page-about .team-card__duties li,
  .page-about .about-rail__link {
    transition: none;
  }

  .page-about .stage-node:hover,
  .page-about .team-card:hover,
  .page-about .team-card:focus-within {
    transform: none;
  }
}