.page-about .about-hero {
  position: relative;
  overflow: hidden;
  padding: calc(var(--header-h) + 40px) 0 52px;
  border-bottom: 1px solid var(--border);
  background: linear-gradient(180deg, var(--abyss), #0c1526 100%);
}

.page-about .about-hero::before {
  content: "";
  position: absolute;
  top: -18%;
  right: -12%;
  width: min(620px, 92vw);
  height: min(620px, 92vw);
  background: linear-gradient(140deg, rgba(37, 224, 196, 0.20), rgba(108, 107, 255, 0.14) 52%, rgba(10, 17, 32, 0) 74%);
  clip-path: polygon(20% 0, 100% 0, 100% 78%, 0 100%);
  pointer-events: none;
  z-index: 0;
}

.page-about .about-hero::after {
  content: "";
  position: absolute;
  inset: 0;
  background-image:
    linear-gradient(rgba(36, 52, 76, 0.55) 1px, transparent 1px),
    linear-gradient(90deg, rgba(36, 52, 76, 0.55) 1px, transparent 1px);
  background-size: 72px 72px;
  -webkit-mask-image: linear-gradient(180deg, rgba(0, 0, 0, 0.75), transparent 72%);
  mask-image: linear-gradient(180deg, rgba(0, 0, 0, 0.75), transparent 72%);
  opacity: 0.4;
  pointer-events: none;
  z-index: 0;
}

.page-about .about-hero__inner {
  position: relative;
  z-index: 1;
  display: grid;
  gap: 34px;
}

.page-about .about-hero__lead .crumb {
  margin-bottom: 20px;
}

.page-about .about-hero__lead h1 {
  margin: 10px 0 18px;
  font-family: var(--font-display);
  font-weight: 900;
  font-size: clamp(30px, 7.4vw, 58px);
  line-height: 1.12;
  letter-spacing: -0.01em;
  color: var(--text);
}

.page-about .about-hero__lede {
  max-width: 60ch;
  margin: 0 0 24px;
  font-size: 16px;
  line-height: 1.8;
  color: var(--muted);
}

.page-about .about-hero__links {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 16px;
}

.page-about .hero-stats {
  list-style: none;
  margin: 0;
  padding: 0;
  border-top: 1px solid var(--border);
}

.page-about .hero-stat {
  display: grid;
  grid-template-columns: 88px minmax(0, 1fr);
  gap: 14px;
  align-items: baseline;
  padding: 14px 0;
  border-bottom: 1px solid var(--border);
}

.page-about .hero-stat__num {
  font-family: var(--font-mono);
  font-size: 22px;
  font-weight: 700;
  letter-spacing: 0.04em;
  color: var(--amber);
}

.page-about .hero-stat__label {
  font-size: 14px;
  line-height: 1.65;
  color: var(--muted);
}

/* 章节 01 · 时间线 */
.page-about .tl {
  list-style: none;
  margin: 0;
  padding: 0;
  position: relative;
}

.page-about .tl::before {
  content: "";
  position: absolute;
  left: 8px;
  top: 8px;
  bottom: 8px;
  width: 1px;
  background: linear-gradient(180deg, var(--cyan), var(--indigo) 55%, var(--amber));
  opacity: 0.6;
}

.page-about .tl__item {
  position: relative;
  padding: 0 0 30px 34px;
}

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

.page-about .tl__item::before {
  content: "";
  position: absolute;
  left: 5px;
  top: 5px;
  width: 7px;
  height: 7px;
  border-radius: 50%;
  background: var(--abyss);
  border: 1px solid var(--cyan);
  box-shadow: 0 0 0 4px rgba(37, 224, 196, 0.12);
}

.page-about .tl__year {
  display: block;
  margin-bottom: 6px;
  font-size: 15px;
  letter-spacing: 0.12em;
  color: var(--cyan);
}

.page-about .tl__title {
  margin: 0 0 8px;
  font-family: var(--font-display);
  font-size: 18px;
  font-weight: 700;
  color: var(--text);
}

.page-about .tl__text {
  margin: 0;
  max-width: 68ch;
  font-size: 15px;
  line-height: 1.78;
  color: var(--muted);
}

/* 章节 02 · 追溯 */
.page-about .trace-lede {
  margin: 0 0 22px;
  max-width: 62ch;
  font-size: 15px;
  line-height: 1.78;
  color: var(--muted);
}

.page-about .batch-rule {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 8px;
  margin-bottom: 26px;
  padding: 16px;
  border: 1px solid var(--border);
  border-radius: var(--radius-sm);
  background: var(--surface);
}

.page-about .batch-rule__seg {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  min-width: 52px;
  padding: 8px 10px;
  border-radius: 8px;
  border: 1px solid rgba(37, 224, 196, 0.45);
  background: rgba(37, 224, 196, 0.10);
  font-family: var(--font-mono);
  font-size: 20px;
  font-weight: 700;
  letter-spacing: 0.06em;
  color: var(--cyan);
}

.page-about .batch-rule__hint {
  flex: 1 1 140px;
  font-size: 13px;
  letter-spacing: 0.06em;
  color: var(--muted);
}

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

.page-about .trace-step {
  position: relative;
  padding: 16px 16px 16px 18px;
  border: 1px solid var(--border);
  border-left: 2px solid var(--border);
  border-radius: var(--radius-sm);
  background: var(--surface);
  transition: border-color 320ms var(--ease);
}

.page-about .trace-step:hover,
.page-about .trace-step:focus-within {
  border-left-color: var(--cyan);
}

.page-about .trace-step__no {
  display: block;
  margin-bottom: 6px;
  font-size: 12px;
  letter-spacing: 0.14em;
  color: var(--cyan);
}

.page-about .trace-step__title {
  margin: 0 0 6px;
  font-size: 16px;
  font-weight: 700;
  color: var(--text);
}

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

.page-about .trace-figure {
  margin: 26px 0 0;
}

/* 章节 03 · 渠道网络 */
.page-about .region-list {
  list-style: none;
  margin: 0;
  padding: 0;
}

.page-about .region-row {
  display: grid;
  grid-template-columns: 66px minmax(0, 1fr) 34px;
  gap: 12px;
  align-items: center;
  padding: 12px 0;
  border-bottom: 1px dashed var(--border);
}

.page-about .region-row:first-child {
  border-top: 1px dashed var(--border);
}

.page-about .region-name {
  font-size: 14px;
  color: var(--text);
}

.page-about .dots {
  display: flex;
  flex-wrap: wrap;
  gap: 5px;
}

.page-about .dots i {
  display: block;
  width: 7px;
  height: 7px;
  border-radius: 2px;
  background: linear-gradient(135deg, var(--cyan), rgba(37, 224, 196, 0.45));
}

.page-about .region-count {
  text-align: right;
  font-size: 15px;
  font-weight: 700;
  color: var(--amber);
}

.page-about .region-foot {
  margin: 16px 0 0;
  font-size: 14px;
  line-height: 1.7;
  color: var(--muted);
}

.page-about .network-side {
  margin-top: 30px;
}

.page-about .network-note {
  margin: 18px 0 0;
  font-size: 15px;
  line-height: 1.78;
  color: var(--muted);
}

/* 章节 04 · 售后 */
.page-about .meter-block {
  padding: 20px;
  border: 1px solid var(--border);
  border-radius: var(--radius);
  background: var(--surface);
}

.page-about .meter-block + .meter-block {
  margin-top: 16px;
}

.page-about .meter-title {
  margin: 0 0 12px;
  font-size: 13px;
  font-weight: 600;
  letter-spacing: 0.14em;
  color: var(--muted);
  text-transform: uppercase;
}

.page-about .meter-figure {
  margin: 0 0 14px;
  font-size: 15px;
  color: var(--text);
}

.page-about .meter-num {
  font-size: 30px;
  font-weight: 700;
  color: var(--amber);
  letter-spacing: 0.04em;
  margin-right: 4px;
}

.page-about .ruler {
  display: flex;
  flex-wrap: wrap;
  gap: 4px;
}

.page-about .ruler__cell {
  display: block;
  width: 13px;
  height: 26px;
  border-radius: 3px;
  border: 1px solid var(--border);
  background: rgba(36, 52, 76, 0.35);
}

.page-about .ruler__cell.is-filled {
  border-color: rgba(37, 224, 196, 0.6);
  background: linear-gradient(180deg, rgba(37, 224, 196, 0.6), rgba(37, 224, 196, 0.14));
}

.page-about .meter-note {
  margin: 14px 0 0;
  font-size: 14px;
  line-height: 1.72;
  color: var(--muted);
}

.page-about .meter-note .mono {
  color: var(--cyan);
  font-weight: 700;
}

.page-about .cadence {
  list-style: none;
  margin: 0;
  padding: 0;
}

.page-about .cadence__item {
  display: grid;
  gap: 6px;
  padding: 14px 0;
  border-bottom: 1px solid var(--border);
}

.page-about .cadence__item:first-child {
  padding-top: 0;
}

.page-about .cadence__item:last-child {
  border-bottom: none;
  padding-bottom: 0;
}

.page-about .cadence__k {
  font-size: 18px;
  font-weight: 700;
  letter-spacing: 0.04em;
  color: var(--cyan);
}

.page-about .cadence__v {
  font-size: 14px;
  line-height: 1.72;
  color: var(--muted);
}

.page-about .flow-title {
  margin: 34px 0 14px;
  font-family: var(--font-display);
  font-size: 18px;
  font-weight: 700;
  color: var(--text);
}

.page-about .flow {
  list-style: none;
  margin: 0;
  padding: 0;
  display: grid;
  gap: 10px;
  counter-reset: flow;
}

.page-about .flow__step {
  display: flex;
  align-items: center;
  gap: 10px;
  padding: 12px 14px;
  border: 1px solid var(--border);
  border-radius: var(--radius-sm);
  background: rgba(17, 28, 47, 0.7);
  font-size: 15px;
  color: var(--text);
}

.page-about .flow__no {
  font-size: 12px;
  letter-spacing: 0.14em;
  color: var(--cyan);
}

.page-about .flow-note {
  margin: 18px 0 0;
  font-size: 14px;
  line-height: 1.72;
  color: var(--muted);
}

/* 章节 05 · 版本迭代 */
.page-about .version-grid {
  display: grid;
  gap: 26px;
}

.page-about .version-copy p {
  margin: 0 0 14px;
  max-width: 66ch;
  font-size: 15px;
  line-height: 1.78;
  color: var(--muted);
}

.page-about .version-link {
  margin: 0 !important;
}

.page-about .data-table caption {
  text-align: left;
  padding: 0 0 10px;
  font-size: 13px;
  letter-spacing: 0.08em;
  color: var(--muted);
}

.page-about .version-banner {
  margin: 30px 0 0;
}

/* 收尾 */
.page-about .about-cta__inner {
  display: grid;
  gap: 22px;
  padding: 26px 22px;
  border: 1px solid var(--border);
  border-radius: var(--radius);
  background:
    linear-gradient(120deg, rgba(242, 179, 61, 0.12), rgba(37, 224, 196, 0.07) 58%, rgba(10, 17, 32, 0) 100%),
    var(--surface);
}

.page-about .about-cta__text h2 {
  margin: 0 0 12px;
  font-family: var(--font-display);
  font-size: clamp(22px, 4.4vw, 30px);
  font-weight: 800;
  letter-spacing: -0.01em;
  color: var(--text);
}

.page-about .about-cta__text p {
  margin: 0;
  max-width: 68ch;
  font-size: 15px;
  line-height: 1.78;
  color: var(--muted);
}

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

@media (min-width: 760px) {
  .page-about .about-hero {
    padding: calc(var(--header-h) + 64px) 0 76px;
  }

  .page-about .tl__item {
    display: grid;
    grid-template-columns: 104px minmax(0, 1fr);
    gap: 0 18px;
    align-items: start;
  }

  .page-about .tl__year {
    margin-bottom: 0;
    padding-top: 2px;
  }

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

  .page-about .about-cta__inner {
    grid-template-columns: minmax(0, 1fr) auto;
    align-items: center;
    padding: 30px 28px;
  }
}

@media (min-width: 980px) {
  .page-about .about-hero__inner {
    grid-template-columns: minmax(0, 7fr) minmax(0, 4fr);
    gap: 56px;
    align-items: end;
  }

  .page-about .trace-figure {
    margin-top: 0;
  }

  .page-about .network-side {
    margin-top: 0;
  }

  .page-about .meter-block + .meter-block {
    margin-top: 0;
  }

  .page-about .version-grid {
    grid-template-columns: minmax(0, 4fr) minmax(0, 8fr);
    gap: 34px;
    align-items: start;
  }

  .page-about .flow {
    grid-template-columns: repeat(5, minmax(0, 1fr));
  }
}

@media (prefers-reduced-motion: reduce) {
  .page-about .trace-step {
    transition: none;
  }
}