.page-about {
  --about-max: 1180px;
  --about-pad: clamp(20px, 4vw, 44px);
}

/* ---------- 首屏 ---------- */
.page-about .about-hero {
  position: relative;
  overflow: hidden;
  padding: clamp(24px, 4vw, 44px) var(--about-pad) clamp(44px, 6vw, 80px);
  border-bottom: 1px solid var(--line);
}

.page-about .about-hero::before {
  content: "";
  position: absolute;
  top: -22%;
  right: -14%;
  width: min(780px, 96vw);
  height: min(640px, 82vw);
  background:
    radial-gradient(120% 120% at 78% 12%, rgba(46, 242, 190, 0.22), transparent 62%),
    linear-gradient(140deg, rgba(91, 61, 245, 0.34), rgba(162, 107, 255, 0.14) 52%, transparent 78%);
  clip-path: polygon(24% 0, 100% 0, 100% 100%, 0 72%);
  pointer-events: none;
  z-index: 0;
}

.page-about .about-hero::after {
  content: "";
  position: absolute;
  left: -8%;
  bottom: -34%;
  width: min(420px, 70vw);
  height: min(420px, 70vw);
  background: radial-gradient(circle, rgba(255, 122, 47, 0.16), transparent 68%);
  pointer-events: none;
  z-index: 0;
}

.page-about .about-hero .breadcrumb {
  position: relative;
  z-index: 1;
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 8px;
  font-size: 12px;
  letter-spacing: 0.08em;
  color: var(--text-dim);
  margin: 0 0 clamp(20px, 3vw, 34px);
}

.page-about .about-hero .breadcrumb a {
  color: var(--text-dim);
  text-decoration: none;
  transition: color 0.2s ease;
}

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

.page-about .about-hero__grid {
  position: relative;
  z-index: 1;
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: clamp(28px, 5vw, 48px);
  max-width: var(--about-max);
  margin: 0 auto;
}

.page-about .about-hero__main .eyebrow {
  margin: 0 0 14px;
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.24em;
  text-transform: uppercase;
  color: var(--cyan);
}

.page-about .about-hero__main h1 {
  margin: 0 0 18px;
  font-size: clamp(32px, 6.4vw, 58px);
  line-height: 1.1;
  letter-spacing: -0.01em;
  color: var(--text);
  max-width: 18em;
}

.page-about .about-hero__lead {
  margin: 0 0 clamp(22px, 3vw, 32px);
  max-width: 34em;
  font-size: clamp(15px, 1.6vw, 17px);
  line-height: 1.8;
  color: var(--text-dim);
}

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

.page-about .about-hero__stats {
  list-style: none;
  margin: 0;
  padding: 0;
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 12px;
}

.page-about .hero-stat {
  display: flex;
  flex-direction: column;
  gap: 6px;
  padding: 14px 16px;
  border: 1px solid var(--line);
  border-radius: var(--r-md);
  background: linear-gradient(150deg, rgba(18, 30, 51, 0.86), rgba(11, 20, 36, 0.38));
  box-shadow: var(--shadow-card);
}

.page-about .hero-stat .stat-value {
  font-family: var(--font-mono);
  font-size: clamp(24px, 3.2vw, 38px);
  font-weight: 700;
  line-height: 1.05;
  color: var(--text);
  font-variant-numeric: tabular-nums;
}

.page-about .hero-stat .stat-value small {
  margin-left: 3px;
  font-size: 0.46em;
  color: var(--cyan);
}

.page-about .hero-stat .stat-label {
  font-size: 12px;
  letter-spacing: 0.06em;
  color: var(--text-dim);
}

/* ---------- 章节索引 ---------- */
.page-about .about-index {
  display: flex;
  gap: 8px;
  overflow-x: auto;
  padding: 14px var(--about-pad);
  border-bottom: 1px solid var(--line);
  background: linear-gradient(90deg, rgba(11, 20, 36, 0.92), rgba(5, 10, 20, 0.55));
  scrollbar-width: thin;
}

.page-about .about-index a {
  flex: 0 0 auto;
  padding: 6px 13px;
  border: 1px solid var(--line);
  border-radius: 999px;
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.06em;
  color: var(--text-dim);
  text-decoration: none;
  white-space: nowrap;
  transition: color 0.2s ease, border-color 0.2s ease, box-shadow 0.2s ease;
}

.page-about .about-index a:hover,
.page-about .about-index a:focus-visible {
  color: var(--cyan);
  border-color: rgba(46, 242, 190, 0.5);
  box-shadow: var(--glow-cyan);
}

/* ---------- 章节骨架 ---------- */
.page-about .about-chapter {
  position: relative;
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 16px;
  max-width: var(--about-max);
  margin: 0 auto;
  padding: clamp(48px, 7vw, 84px) var(--about-pad);
}

.page-about .about-chapter + .about-chapter::before {
  content: "";
  position: absolute;
  top: 0;
  left: var(--about-pad);
  right: var(--about-pad);
  height: 1px;
  background: linear-gradient(90deg, rgba(46, 242, 190, 0.55), rgba(162, 107, 255, 0.36) 42%, transparent);
}

.page-about .chapter-no {
  display: flex;
  align-items: center;
  gap: 12px;
}

.page-about .chapter-no .num {
  font-family: var(--font-mono);
  font-size: 13px;
  font-weight: 700;
  letter-spacing: 0.2em;
  color: var(--cyan);
}

.page-about .chapter-rail {
  flex: 1;
  height: 2px;
  border-radius: 999px;
  background: linear-gradient(90deg, var(--cyan), rgba(162, 107, 255, 0.35), transparent);
}

.page-about .chapter-main {
  position: relative;
  z-index: 1;
  min-width: 0;
}

.page-about .chapter-main .section-title {
  margin: 0 0 16px;
  font-size: clamp(24px, 3.6vw, 38px);
  line-height: 1.22;
  color: var(--text);
}

.page-about .chapter-main .section-lead {
  margin: 0 0 clamp(22px, 3vw, 34px);
  max-width: 40em;
  font-size: 15px;
  line-height: 1.8;
  color: var(--text-dim);
}

.page-about .chapter-body p {
  margin: 0 0 16px;
  font-size: 15px;
  line-height: 1.8;
  color: var(--text-dim);
}

.page-about .chapter-cols {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 22px;
}

.page-about .chapter-note {
  padding: 20px 22px;
  border: 1px solid var(--line);
  border-left: 3px solid var(--violet);
  border-radius: var(--r-md);
  background: linear-gradient(160deg, rgba(27, 43, 71, 0.72), rgba(11, 20, 36, 0.42));
}

.page-about .chapter-note h3 {
  margin: 0 0 12px;
  font-size: 14px;
  letter-spacing: 0.1em;
  color: var(--text);
}

.page-about .chapter-note ul {
  list-style: none;
  margin: 0;
  padding: 0;
  display: grid;
  gap: 12px;
}

.page-about .chapter-note li {
  position: relative;
  padding-left: 16px;
  font-size: 14px;
  line-height: 1.75;
  color: var(--text-dim);
}

.page-about .chapter-note li::before {
  content: "";
  position: absolute;
  left: 0;
  top: 9px;
  width: 6px;
  height: 6px;
  border-radius: 50%;
  background: var(--cyan);
  box-shadow: 0 0 8px rgba(46, 242, 190, 0.7);
}

.page-about .chapter-note strong {
  display: block;
  color: var(--text);
  font-weight: 700;
}

.page-about a {
  color: var(--cyan);
  text-decoration: none;
  border-bottom: 1px solid rgba(46, 242, 190, 0.35);
  transition: border-color 0.2s ease;
}

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

/* ---------- 团队 ---------- */
.page-about .team-split {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 24px;
}

.page-about .team-nums {
  display: grid;
  gap: 14px;
}

.page-about .team-num {
  display: flex;
  align-items: flex-start;
  gap: 18px;
  padding: 18px 20px;
  border: 1px solid var(--line);
  border-left: 3px solid var(--cyan);
  border-radius: var(--r-md);
  background: linear-gradient(120deg, rgba(18, 30, 51, 0.92), rgba(11, 20, 36, 0.5));
  box-shadow: var(--shadow-card);
}

.page-about .team-num:nth-child(2) {
  border-left-color: var(--violet);
}

.page-about .team-num:nth-child(3) {
  border-left-color: var(--orange);
}

.page-about .team-num .stat-num {
  flex: 0 0 auto;
  font-family: var(--font-mono);
  font-size: clamp(34px, 4.6vw, 54px);
  font-weight: 700;
  line-height: 1;
  color: var(--text);
  font-variant-numeric: tabular-nums;
}

.page-about .team-num__body h3 {
  margin: 2px 0 8px;
  font-size: 16px;
  color: var(--text);
}

.page-about .team-num__body p {
  margin: 0;
  font-size: 14px;
  line-height: 1.75;
  color: var(--text-dim);
}

.page-about .team-split .media-frame {
  border-radius: var(--r-lg);
  overflow: hidden;
  border: 1px solid var(--line);
}

/* ---------- 时间轴 ---------- */
.page-about .about-chapter--timeline {
  overflow: hidden;
}

.page-about .chapter-deco {
  position: absolute;
  top: 8%;
  right: -20%;
  width: min(520px, 74vw);
  opacity: 0.13;
  pointer-events: none;
  z-index: 0;
}

.page-about .chapter-deco img {
  display: block;
  width: 100%;
  height: auto;
  max-width: 100%;
}

.page-about .milestones {
  list-style: none;
  margin: 0;
  padding: 0;
  position: relative;
}

.page-about .milestones::before {
  content: "";
  position: absolute;
  left: 11px;
  top: 8px;
  bottom: 8px;
  width: 2px;
  border-radius: 999px;
  background: linear-gradient(180deg, var(--cyan), var(--violet) 55%, rgba(91, 61, 245, 0.12));
}

.page-about .milestone {
  position: relative;
  padding: 0 0 30px 42px;
}

.page-about .milestone:last-child {
  padding-bottom: 0;
}

.page-about .milestone::before {
  content: "";
  position: absolute;
  left: 4px;
  top: 6px;
  width: 16px;
  height: 16px;
  border-radius: 50%;
  background: var(--bg-deep);
  border: 2px solid var(--cyan);
  box-shadow: 0 0 12px rgba(46, 242, 190, 0.5);
  transition: transform 0.25s ease, box-shadow 0.25s ease, border-color 0.25s ease;
  z-index: 1;
}

.page-about .milestone:hover::before,
.page-about .milestone:focus-within::before {
  transform: scale(1.35);
  border-color: var(--orange);
  box-shadow: 0 0 18px rgba(255, 122, 47, 0.6);
}

.page-about .ms-year {
  display: block;
  font-family: var(--font-mono);
  font-size: clamp(20px, 2.6vw, 28px);
  font-weight: 700;
  letter-spacing: 0.04em;
  color: var(--cyan);
  margin-bottom: 6px;
  font-variant-numeric: tabular-nums;
}

.page-about .ms-body h3 {
  margin: 0 0 6px;
  font-size: 16px;
  color: var(--text);
}

.page-about .ms-body p {
  margin: 0;
  font-size: 14px;
  line-height: 1.75;
  color: var(--text-dim);
  max-width: 34em;
}

/* ---------- 流程 ---------- */
.page-about .flow {
  list-style: none;
  margin: 0 0 22px;
  padding: 0;
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 14px;
}

.page-about .flow-step {
  position: relative;
  padding: 22px 20px 20px;
  border: 1px solid var(--line);
  border-radius: var(--r-md);
  background: rgba(18, 30, 51, 0.7);
  overflow: hidden;
}

.page-about .flow-step::after {
  content: "";
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  height: 3px;
}

.page-about .flow-step:nth-child(1)::after {
  background: var(--cyan);
}

.page-about .flow-step:nth-child(2)::after {
  background: linear-gradient(90deg, var(--cyan), var(--violet));
}

.page-about .flow-step:nth-child(3)::after {
  background: linear-gradient(90deg, var(--violet), var(--indigo));
}

.page-about .flow-step:nth-child(4)::after {
  background: var(--indigo);
}

.page-about .flow-no {
  display: block;
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.2em;
  color: var(--text-mute);
  margin-bottom: 10px;
}

.page-about .flow-step h3 {
  margin: 0 0 8px;
  font-size: 16px;
  color: var(--text);
}

.page-about .flow-step p {
  margin: 0;
  font-size: 14px;
  line-height: 1.75;
  color: var(--text-dim);
}

.page-about .flow-foot {
  margin: 0;
  padding: 16px 20px;
  border-radius: var(--r-md);
  border: 1px dashed var(--line);
  font-size: 14px;
  line-height: 1.75;
  color: var(--text-dim);
  background: linear-gradient(90deg, rgba(255, 122, 47, 0.08), transparent 70%);
}

/* ---------- 合作 ---------- */
.page-about .partners {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 18px;
}

.page-about .partner {
  padding: 22px 20px;
  border: 1px solid var(--line);
  border-radius: var(--r-lg);
  background: linear-gradient(160deg, rgba(27, 43, 71, 0.72), rgba(11, 20, 36, 0.4));
  box-shadow: var(--shadow-card);
}

.page-about .partner-num {
  display: block;
  font-family: var(--font-mono);
  font-size: clamp(30px, 3.6vw, 44px);
  font-weight: 700;
  line-height: 1;
  color: var(--orange);
  margin-bottom: 12px;
  font-variant-numeric: tabular-nums;
}

.page-about .partner h3 {
  margin: 0 0 8px;
  font-size: 16px;
  color: var(--text);
}

.page-about .partner p {
  margin: 0;
  font-size: 14px;
  line-height: 1.75;
  color: var(--text-dim);
}

.page-about .partners-foot {
  margin: 26px 0 0;
  font-size: 14px;
  line-height: 1.8;
  color: var(--text-dim);
}

/* ---------- 覆盖 ---------- */
.page-about .reach-grid {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 24px;
}

.page-about .reach-grid .media-frame {
  border-radius: var(--r-lg);
  overflow: hidden;
  border: 1px solid var(--line);
}

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

.page-about .reach-facts li {
  display: grid;
  grid-template-columns: 88px minmax(0, 1fr);
  align-items: baseline;
  gap: 14px;
  padding-bottom: 14px;
  border-bottom: 1px solid rgba(42, 59, 88, 0.6);
}

.page-about .reach-facts li:last-child {
  border-bottom: none;
  padding-bottom: 0;
}

.page-about .reach-k {
  font-family: var(--font-mono);
  font-size: clamp(26px, 3.4vw, 38px);
  font-weight: 700;
  line-height: 1;
  color: var(--cyan);
  font-variant-numeric: tabular-nums;
}

.page-about .reach-v {
  font-size: 14px;
  line-height: 1.75;
  color: var(--text-dim);
}

/* ---------- 指标 ---------- */
.page-about .latency {
  list-style: none;
  margin: 0 0 24px;
  padding: 0;
  display: grid;
  gap: 20px;
}

.page-about .latency-item {
  display: grid;
  grid-template-columns: 96px minmax(0, 1fr);
  align-items: center;
  gap: 8px 18px;
}

.page-about .latency-val {
  grid-row: span 2;
  font-family: var(--font-mono);
  font-size: clamp(30px, 4vw, 46px);
  font-weight: 700;
  line-height: 1;
  color: var(--text);
  font-variant-numeric: tabular-nums;
}

.page-about .latency-val small {
  font-size: 0.42em;
  margin-left: 3px;
  color: var(--text-dim);
}

.page-about .latency-what {
  font-size: 14px;
  line-height: 1.6;
  color: var(--text-dim);
}

.page-about .latency-bar {
  position: relative;
  display: block;
  height: 6px;
  border-radius: 999px;
  background: rgba(42, 59, 88, 0.55);
  overflow: hidden;
}

.page-about .latency-bar::after {
  content: "";
  position: absolute;
  top: 0;
  left: 0;
  bottom: 0;
  border-radius: 999px;
  background: linear-gradient(90deg, var(--cyan), var(--violet));
}

.page-about .latency-item:nth-child(1) .latency-bar::after {
  width: 22%;
}

.page-about .latency-item:nth-child(2) .latency-bar::after {
  width: 34%;
}

.page-about .latency-item:nth-child(3) .latency-bar::after {
  width: 66%;
}

.page-about .latency-item:nth-child(4) .latency-bar::after {
  width: 100%;
}

.page-about .metrics-foot {
  margin: 0;
  font-size: 14px;
  line-height: 1.8;
  color: var(--text-dim);
}

/* ---------- 响应式 ---------- */
@media (min-width: 720px) {
  .page-about .about-hero__stats {
    grid-template-columns: repeat(4, minmax(0, 1fr));
  }

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

  .page-about .partner:nth-child(2) {
    transform: translateY(26px);
  }

  .page-about .partners {
    margin-bottom: 26px;
  }
}

@media (min-width: 860px) {
  .page-about .team-split {
    grid-template-columns: minmax(0, 1.1fr) minmax(0, 0.9fr);
    align-items: start;
  }

  .page-about .reach-grid {
    grid-template-columns: minmax(0, 1fr) minmax(0, 0.95fr);
    align-items: center;
  }

  .page-about .flow {
    grid-template-columns: repeat(4, minmax(0, 1fr));
    gap: 0;
  }

  .page-about .flow-step {
    border-radius: 0;
    border-right: none;
  }

  .page-about .flow-step:first-child {
    border-radius: var(--r-md) 0 0 var(--r-md);
  }

  .page-about .flow-step:last-child {
    border-radius: 0 var(--r-md) var(--r-md) 0;
    border-right: 1px solid var(--line);
  }

  .page-about .flow-step + .flow-step::before {
    content: "";
    position: absolute;
    left: -9px;
    top: 50%;
    width: 16px;
    height: 16px;
    transform: translateY(-50%) rotate(45deg);
    background: var(--bg-deep);
    border-top: 2px solid var(--cyan);
    border-right: 2px solid var(--cyan);
    z-index: 2;
  }
}

@media (min-width: 980px) {
  .page-about .about-hero__grid {
    grid-template-columns: minmax(0, 1.45fr) minmax(0, 0.75fr);
    align-items: end;
    gap: 48px;
  }

  .page-about .about-hero__stats {
    grid-template-columns: minmax(0, 1fr);
    gap: 14px;
    padding-left: 24px;
    border-left: 1px solid var(--line);
  }

  .page-about .about-chapter {
    grid-template-columns: 88px minmax(0, 1fr);
    gap: 36px;
    padding-block: clamp(64px, 8vw, 96px);
  }

  .page-about .chapter-no {
    flex-direction: column;
    align-items: flex-start;
    gap: 14px;
    align-self: start;
    position: sticky;
    top: calc(var(--cmd-h) + 24px);
  }

  .page-about .chapter-rail {
    width: 2px;
    height: 128px;
    background: linear-gradient(180deg, var(--cyan), rgba(162, 107, 255, 0.45) 55%, transparent);
  }

  .page-about .chapter-cols {
    grid-template-columns: minmax(0, 1.6fr) minmax(0, 1fr);
    gap: 32px;
    align-items: start;
  }
}

@media (prefers-reduced-motion: reduce) {
  .page-about .milestone::before,
  .page-about .about-index a,
  .page-about a {
    transition: none;
  }

  .page-about .partner:nth-child(2) {
    transform: none;
  }
}