.page-about {
  --about-node: 28px;
  --about-edge: clamp(18px, 4vw, 34px);
  display: block;
}

/* ---------- 斜切接缝 ---------- */
.page-about .about-seam {
  height: 1px;
  margin: 0;
  border: 0;
  background: linear-gradient(90deg, transparent 0%, var(--line) 16%, var(--cyan-deep) 50%, var(--line) 84%, transparent 100%);
  opacity: .75;
  transform: skewY(-0.35deg);
}

/* ---------- 首屏 ---------- */
.page-about .about-hero {
  position: relative;
  isolation: isolate;
  overflow: hidden;
  padding: clamp(30px, 6vw, 58px) 0 clamp(34px, 7vw, 70px);
}

.page-about .about-hero::before {
  content: "";
  position: absolute;
  inset: 0;
  z-index: -1;
  pointer-events: none;
  background:
    radial-gradient(120% 90% at 88% -10%, rgba(37, 240, 206, .16), transparent 62%),
    radial-gradient(90% 70% at 6% 110%, rgba(255, 106, 26, .08), transparent 60%),
    linear-gradient(180deg, var(--panel-deep) 0%, transparent 78%);
}

.page-about .about-hero-title {
  margin: 14px 0 0;
  max-width: 18ch;
  font-size: clamp(31px, 6.4vw, 74px);
  line-height: 1.04;
  font-weight: 900;
  letter-spacing: -0.02em;
  color: var(--paper);
}

.page-about .about-hero-lead {
  margin-top: clamp(18px, 2.6vw, 26px);
  max-width: 60ch;
  color: var(--mist);
}

.page-about .hero-facts {
  display: flex;
  flex-wrap: wrap;
  gap: 16px 40px;
  margin: clamp(26px, 4vw, 42px) 0 0;
  padding: clamp(18px, 2.6vw, 24px) 0 0;
  border-top: 1px solid var(--line);
  list-style: none;
}

.page-about .hero-fact-num {
  display: block;
  font-size: clamp(25px, 3.6vw, 36px);
  line-height: 1;
  color: var(--ice);
}

.page-about .hero-fact-label {
  display: block;
  margin-top: 6px;
  font-size: 13px;
  letter-spacing: .02em;
  color: var(--mist);
}

/* ---------- 起点 ---------- */
.page-about .origin-grid {
  display: grid;
  gap: clamp(24px, 4vw, 46px);
}

.page-about .section-title {
  font-size: clamp(26px, 4.6vw, 46px);
  line-height: 1.12;
  letter-spacing: -0.01em;
}

.page-about .origin-body .prose + .prose {
  margin-top: 16px;
}

.page-about .origin-media {
  margin: 0;
  border: 1px solid var(--line);
}

.page-about .media-frame {
  display: block;
  position: relative;
  overflow: hidden;
  background: var(--panel);
}

.page-about .media-frame img {
  display: block;
  width: 100%;
  height: auto;
  max-width: 100%;
  object-fit: cover;
  filter: saturate(.62) contrast(1.06) brightness(.86);
}

.page-about .aside-note {
  margin-top: clamp(20px, 3vw, 28px);
}

/* ---------- 时间轴 ---------- */
.page-about .timeline-list {
  position: relative;
  margin: clamp(26px, 4vw, 42px) 0 0;
  padding: 0 0 0 0;
  list-style: none;
  display: grid;
  gap: clamp(18px, 3vw, 28px);
}

.page-about .timeline-list::before {
  content: "";
  position: absolute;
  left: calc(var(--about-node) / 2 - 1px);
  top: 10px;
  bottom: 10px;
  width: 2px;
  background: linear-gradient(180deg, var(--cyan) 0%, var(--cyan-deep) 34%, var(--line) 100%);
  opacity: .85;
}

.page-about .timeline-item {
  position: relative;
  padding-left: calc(var(--about-node) + 18px);
}

.page-about .timeline-node {
  position: absolute;
  left: 0;
  top: 4px;
  width: var(--about-node);
  height: var(--about-node);
  display: grid;
  place-items: center;
  border: 1px solid var(--line);
  border-radius: var(--radius);
  background: var(--panel-deep);
  color: var(--mist);
  font-family: var(--font-mono);
  font-size: 11px;
  line-height: 1;
  text-decoration: none;
  transition: background .28s var(--ease), border-color .28s var(--ease), color .28s var(--ease), box-shadow .28s var(--ease);
}

.page-about .timeline-node:hover,
.page-about .timeline-node:focus-visible,
.page-about .timeline-item:target .timeline-node {
  border-color: var(--cyan);
  background: var(--cyan);
  color: var(--ink);
  box-shadow: 0 0 0 5px rgba(37, 240, 206, .13);
  outline: none;
}

.page-about .stage-panel {
  position: relative;
  overflow: hidden;
  padding: clamp(20px, 3.4vw, 34px);
  background: var(--panel);
  border: 1px solid var(--line);
  border-left: 2px solid var(--line);
  transition: border-color .32s var(--ease), transform .32s var(--ease);
}

.page-about .stage-panel:hover {
  border-color: rgba(37, 240, 206, .45);
  border-left-color: var(--cyan);
}

.page-about .timeline-item:target .stage-panel {
  border-color: rgba(37, 240, 206, .55);
  border-left-color: var(--cyan);
}

.page-about .stage-watermark {
  position: absolute;
  right: 10px;
  bottom: -30px;
  font-size: clamp(92px, 20vw, 180px);
  line-height: .8;
  color: var(--cyan-deep);
  opacity: .14;
  pointer-events: none;
  user-select: none;
}

.page-about .stage-kicker {
  position: relative;
  margin: 0;
  font-size: 12px;
  letter-spacing: .06em;
  color: var(--cyan);
}

.page-about .stage-title {
  position: relative;
  margin: 10px 0 0;
  max-width: 26ch;
  font-size: clamp(19px, 2.6vw, 26px);
  line-height: 1.3;
  font-weight: 700;
  color: var(--paper);
}

.page-about .stage-panel p:last-child {
  position: relative;
  margin: 12px 0 0;
  max-width: 58ch;
  font-size: 15.5px;
  line-height: 1.8;
  color: var(--mist);
}

/* ---------- 团队 ---------- */
.page-about .team-banner {
  margin: clamp(22px, 3.4vw, 32px) 0 0;
  border: 1px solid var(--line);
}

.page-about .team-bar {
  display: flex;
  flex-direction: column;
  gap: 8px;
  margin-top: clamp(20px, 3vw, 30px);
}

.page-about .team-seg {
  display: flex;
  align-items: baseline;
  justify-content: space-between;
  gap: 12px;
  padding: 13px 16px;
  border: 1px solid var(--line);
  border-left: 3px solid var(--cyan-deep);
  border-radius: var(--radius);
  background: var(--panel);
  transition: background .3s var(--ease), border-color .3s var(--ease);
}

.page-about .team-seg:hover {
  background: var(--panel-deep);
  border-color: var(--line);
  border-left-color: var(--cyan);
}

.page-about .team-seg-name {
  font-size: 14px;
  color: var(--paper);
}

.page-about .team-seg-num {
  font-size: 20px;
  color: var(--ice);
}

.page-about .team-cards {
  display: grid;
  gap: 14px;
  margin-top: clamp(20px, 3vw, 28px);
}

.page-about .team-card {
  padding: clamp(18px, 2.6vw, 24px);
  background: var(--panel-deep);
  border: 1px solid var(--line);
  border-radius: var(--radius);
}

.page-about .team-card-title {
  margin: 0;
  font-size: 16px;
  font-weight: 700;
  color: var(--paper);
}

.page-about .team-card p {
  margin: 10px 0 0;
  font-size: 14.5px;
  line-height: 1.8;
  color: var(--mist);
}

/* ---------- 覆盖范围 ---------- */
.page-about .coverage-grid {
  display: grid;
  gap: 14px;
  margin-top: clamp(24px, 3.6vw, 36px);
}

.page-about .coverage-card {
  position: relative;
  overflow: hidden;
  padding: clamp(20px, 3vw, 30px);
  background: var(--panel);
  border: 1px solid var(--line);
  border-radius: var(--radius);
}

.page-about .coverage-card::after {
  content: "";
  position: absolute;
  left: 0;
  right: 0;
  bottom: 0;
  height: 2px;
  background: linear-gradient(90deg, var(--cyan), rgba(37, 240, 206, 0) 78%);
  opacity: .55;
}

.page-about .coverage-num {
  display: block;
  font-family: var(--font-mono);
  font-size: clamp(36px, 6.6vw, 58px);
  line-height: 1;
  letter-spacing: -0.02em;
  color: var(--ice);
}

.page-about .coverage-num small {
  font-family: var(--font-mono);
  font-size: .45em;
  color: var(--orange);
  margin-left: 2px;
}

.page-about .coverage-label {
  margin: 12px 0 0;
  font-size: 15px;
  font-weight: 500;
  color: var(--paper);
}

.page-about .coverage-note {
  margin: 8px 0 0;
  font-size: 13.5px;
  line-height: 1.75;
  color: var(--mist);
}

/* ---------- 合作生态 ---------- */
.page-about .partners-grid {
  display: grid;
  gap: clamp(24px, 4vw, 44px);
}

.page-about .partners-media {
  margin: 0;
  border: 1px solid var(--line);
}

.page-about .partners-body .prose {
  margin-top: 14px;
}

.page-about .partner-list {
  display: grid;
  gap: 18px;
  margin: clamp(22px, 3vw, 30px) 0 0;
  padding: 0;
  list-style: none;
}

.page-about .partner-item {
  display: grid;
  grid-template-columns: auto minmax(0, 1fr);
  gap: 16px;
  padding-top: 16px;
  border-top: 1px solid var(--line);
}

.page-about .partner-num {
  font-size: 24px;
  line-height: 1.2;
  color: var(--cyan);
}

.page-about .partner-item h3 {
  margin: 0;
  font-size: 16px;
  font-weight: 700;
  color: var(--paper);
}

.page-about .partner-item p {
  margin: 8px 0 0;
  font-size: 14.5px;
  line-height: 1.78;
  color: var(--mist);
}

.page-about .partners-cta-line {
  margin: 22px 0 0;
  font-size: 14.5px;
  line-height: 1.8;
  color: var(--mist);
}

.page-about .partners-cta-line a {
  color: var(--cyan);
  text-decoration: none;
  border-bottom: 1px solid rgba(37, 240, 206, .4);
}

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

/* ---------- 为什么选择我们 ---------- */
.page-about .why-grid {
  display: grid;
  gap: 14px;
  margin-top: clamp(24px, 3.6vw, 36px);
}

.page-about .why-item {
  position: relative;
  padding: clamp(20px, 3vw, 28px) clamp(18px, 3vw, 26px);
  background: var(--panel-deep);
  border: 1px solid var(--line);
  border-top: 2px solid var(--cyan-deep);
  border-radius: var(--radius);
  transition: border-top-color .3s var(--ease), background .3s var(--ease);
}

.page-about .why-item:hover {
  border-top-color: var(--cyan);
  background: var(--panel);
}

.page-about .why-index {
  display: block;
  font-size: 12px;
  letter-spacing: .08em;
  color: var(--cyan-deep);
}

.page-about .why-item h3 {
  margin: 12px 0 0;
  font-size: clamp(17px, 2vw, 20px);
  font-weight: 700;
  color: var(--paper);
}

.page-about .why-item p {
  margin: 10px 0 0;
  font-size: 14.5px;
  line-height: 1.8;
  color: var(--mist);
}

.page-about .about-cta {
  display: flex;
  flex-direction: column;
  gap: 18px;
  margin-top: clamp(26px, 4vw, 40px);
  padding: clamp(20px, 3vw, 28px);
  background: linear-gradient(115deg, rgba(37, 240, 206, .1), rgba(11, 17, 24, .9) 58%);
  border: 1px solid var(--line);
  border-left: 3px solid var(--cyan);
  border-radius: var(--radius);
}

.page-about .about-cta-text {
  margin: 0;
  font-size: 15px;
  line-height: 1.8;
  color: var(--paper);
}

.page-about .about-cta-actions {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
}

/* ---------- 断点 ---------- */
@media (min-width: 720px) {
  .page-about .coverage-grid {
    grid-template-columns: repeat(2, minmax(0, 1fr));
    gap: 20px 24px;
  }

  .page-about .coverage-card:nth-child(even) {
    margin-top: 32px;
  }

  .page-about .team-cards {
    grid-template-columns: repeat(2, minmax(0, 1fr));
    gap: 16px;
  }

  .page-about .why-grid {
    grid-template-columns: repeat(2, minmax(0, 1fr));
    gap: 16px;
  }
}

@media (min-width: 860px) {
  .page-about .team-bar {
    flex-direction: row;
    align-items: stretch;
    height: 96px;
    gap: 6px;
  }

  .page-about .team-seg {
    flex-direction: column;
    align-items: flex-start;
    justify-content: center;
    gap: 8px;
    padding: 16px 18px;
    border-left-width: 1px;
    border-top: 3px solid var(--cyan-deep);
  }

  .page-about .team-seg:nth-child(1) {
    flex: 18 1 0;
    border-top-color: var(--cyan);
  }

  .page-about .team-seg:nth-child(2) {
    flex: 9 1 0;
    border-top-color: var(--cyan-deep);
  }

  .page-about .team-seg:nth-child(3) {
    flex: 7 1 0;
    border-top-color: var(--ice);
  }

  .page-about .team-seg:nth-child(4) {
    flex: 8 1 0;
    border-top-color: var(--orange);
  }

  .page-about .team-seg-name {
    font-size: 13.5px;
    white-space: nowrap;
  }
}

@media (min-width: 960px) {
  .page-about .origin-grid {
    grid-template-columns: minmax(0, 7fr) minmax(0, 5fr);
    align-items: start;
  }

  .page-about .partners-grid {
    grid-template-columns: minmax(0, 4fr) minmax(0, 8fr);
    align-items: start;
  }

  .page-about .section-head .lead {
    max-width: 62ch;
  }

  .page-about .about-cta {
    flex-direction: row;
    align-items: center;
    justify-content: space-between;
  }

  .page-about .about-cta-text {
    max-width: 58ch;
  }
}

@media (min-width: 1180px) {
  .page-about .timeline-item {
    padding-left: calc(var(--about-node) + 26px);
  }

  .page-about .stage-panel {
    padding: 36px 40px;
  }
}

@media (prefers-reduced-motion: reduce) {
  .page-about .timeline-node,
  .page-about .stage-panel,
  .page-about .team-seg,
  .page-about .why-item {
    transition: none;
  }
}