.page-about {
  --about-dash: rgba(147, 163, 188, 0.32);
  --about-soft-line: rgba(30, 42, 66, 0.85);
  display: block;
  padding-bottom: clamp(48px, 8vw, 96px);
}

.page-about .breadcrumb {
  padding-top: clamp(20px, 3vw, 34px);
  margin-bottom: clamp(20px, 3vw, 36px);
}

/* ---------- 首屏 ---------- */

.page-about .about-hero {
  position: relative;
  isolation: isolate;
  display: grid;
  grid-template-columns: 1fr;
  gap: clamp(22px, 3.5vw, 44px);
  padding-bottom: clamp(34px, 6vw, 68px);
}

.page-about .about-hero::before {
  content: "";
  position: absolute;
  inset: -8% -4% 24% -4%;
  z-index: -1;
  pointer-events: none;
  background:
    radial-gradient(58% 52% at 20% 0%, rgba(255, 122, 47, 0.2), transparent 70%),
    radial-gradient(46% 52% at 80% 6%, rgba(61, 224, 208, 0.13), transparent 72%);
}

@media (min-width: 900px) {
  .page-about .about-hero {
    grid-template-columns: minmax(0, 5fr) minmax(0, 7fr);
    align-items: center;
  }
}

.page-about .about-hero__title {
  margin: 10px 0 16px;
  font-family: var(--font-display);
  font-size: clamp(2.1rem, 5.6vw, 3.5rem);
  font-weight: 700;
  line-height: 1.16;
  letter-spacing: -0.02em;
  color: var(--c-fog);
  max-width: 16ch;
}

.page-about .about-hero__lede {
  margin: 0;
  max-width: 40ch;
  color: var(--c-body);
  line-height: 1.8;
}

.page-about .about-hero__more {
  margin: 14px 0 0;
  font-size: 0.9rem;
}

.page-about .about-hero__more a {
  color: var(--c-cyan);
  text-decoration: none;
  border-bottom: 1px solid rgba(61, 224, 208, 0.34);
  transition: border-color 0.22s var(--ease), color 0.22s var(--ease);
}

.page-about .about-hero__more a:hover {
  border-bottom-color: var(--c-cyan);
}

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

.page-about .about-hero__meta {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
  margin-top: 22px;
}

.page-about .about-hero__media {
  position: relative;
  margin: 0;
  border-radius: var(--radius-lg);
  overflow: hidden;
  box-shadow: 0 28px 64px -34px rgba(0, 0, 0, 0.85);
}

.page-about .about-hero__media::after {
  content: "";
  position: absolute;
  inset: 0;
  pointer-events: none;
  background: linear-gradient(205deg, rgba(255, 178, 92, 0.16), transparent 45%);
}

/* ---------- 1:2 分屏长滚 ---------- */

.page-about .about-layout {
  display: grid;
  grid-template-columns: 1fr;
  gap: clamp(20px, 4vw, 40px);
  align-items: start;
}

@media (min-width: 1000px) {
  .page-about .about-layout {
    grid-template-columns: minmax(0, 1fr) minmax(0, 2fr);
    gap: clamp(32px, 5vw, 78px);
  }
}

.page-about .about-rail__inner {
  display: flex;
  flex-direction: column;
  gap: 12px;
}

.page-about .about-rail__eyebrow {
  margin: 0;
}

@media (min-width: 1000px) {
  .page-about .about-rail__inner {
    position: sticky;
    top: 132px;
  }
}

.page-about .rail-index {
  list-style: none;
  margin: 0;
  padding: 0 0 6px;
  display: flex;
  flex-direction: row;
  gap: 6px;
  overflow-x: auto;
  scrollbar-width: none;
}

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

.page-about .rail-index__link {
  display: inline-flex;
  align-items: center;
  gap: 9px;
  min-height: 44px;
  padding: 8px 14px;
  border-radius: var(--radius-pill);
  border: 1px solid var(--c-line);
  background: rgba(13, 22, 38, 0.62);
  color: var(--c-mute);
  font-size: 0.9rem;
  text-decoration: none;
  white-space: nowrap;
  transition: color 0.22s var(--ease), background-color 0.22s var(--ease),
    border-color 0.22s var(--ease), transform 0.22s var(--ease);
}

.page-about .rail-index__num {
  font-size: 0.74rem;
  letter-spacing: 0.1em;
  color: var(--c-dawn);
}

.page-about .rail-index__link:hover {
  color: var(--c-fog);
  border-color: rgba(61, 224, 208, 0.5);
  background: rgba(61, 224, 208, 0.08);
  transform: translateY(-2px);
}

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

@media (min-width: 1000px) {
  .page-about .rail-index {
    flex-direction: column;
    gap: 4px;
    overflow: visible;
    padding-bottom: 0;
  }

  .page-about .rail-index__link {
    border-radius: var(--radius-md);
    border-color: transparent;
    border-left: 2px solid transparent;
    background: transparent;
    padding: 10px 12px 10px 16px;
    white-space: normal;
  }

  .page-about .rail-index__link:hover {
    transform: translateX(3px);
    border-left-color: var(--c-cyan);
    background: rgba(61, 224, 208, 0.06);
  }
}

.page-about .rail-ruler {
  display: none;
}

@media (min-width: 1000px) {
  .page-about .rail-ruler {
    display: block;
    margin-top: 10px;
    height: 200px;
    border-left: 1px dashed var(--about-dash);
    padding-left: 10px;
    background-image: repeating-linear-gradient(
      to bottom,
      var(--about-dash) 0 1px,
      transparent 1px 12px
    );
    background-size: 8px 12px;
    background-repeat: repeat-y;
  }
}

/* ---------- 章节画布 ---------- */

.page-about .chapter {
  scroll-margin-top: 128px;
}

.page-about .chapter + .chapter {
  position: relative;
  margin-top: clamp(34px, 5vw, 62px);
  padding-top: clamp(34px, 5vw, 62px);
}

.page-about .chapter + .chapter::before {
  content: "";
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  height: 1px;
  background: linear-gradient(
    90deg,
    rgba(255, 122, 47, 0.5),
    rgba(61, 224, 208, 0.2) 40%,
    transparent 82%
  );
}

.page-about .chapter__num {
  margin: 0 0 10px;
  font-size: 0.78rem;
  letter-spacing: 0.18em;
  color: var(--c-dawn);
}

.page-about .chapter__title {
  margin: 0 0 14px;
  font-family: var(--font-display);
  font-weight: 700;
  font-size: clamp(1.55rem, 3.4vw, 2.3rem);
  line-height: 1.26;
  letter-spacing: -0.015em;
  color: var(--c-fog);
}

.page-about .chapter__lede {
  margin: 0 0 clamp(22px, 3vw, 32px);
  max-width: 46ch;
  line-height: 1.78;
}

.page-about .chapter__body {
  margin: 0 0 clamp(18px, 2.4vw, 26px);
  max-width: 52ch;
  color: var(--c-body);
  line-height: 1.82;
}

.page-about .chapter__figure {
  margin: clamp(22px, 3vw, 34px) 0 0;
  border-radius: var(--radius-lg);
  overflow: hidden;
}

/* ---------- 01 准则 ---------- */

.page-about .rule-list {
  list-style: none;
  margin: 0;
  padding: 0;
  display: grid;
  gap: 0;
}

.page-about .rule {
  display: grid;
  grid-template-columns: auto minmax(0, 1fr);
  column-gap: 16px;
  row-gap: 5px;
  padding: 20px 0;
  border-top: 1px solid var(--about-soft-line);
  transition: background-color 0.24s var(--ease), padding-left 0.24s var(--ease);
}

.page-about .rule:first-child {
  border-top-color: rgba(255, 122, 47, 0.42);
}

.page-about .rule:hover {
  padding-left: 10px;
  background: rgba(13, 22, 38, 0.6);
}

.page-about .rule__num {
  grid-row: 1 / 3;
  padding-top: 4px;
  font-size: 0.8rem;
  letter-spacing: 0.1em;
  color: var(--c-cyan);
}

.page-about .rule__title {
  margin: 0;
  font-size: 1.05rem;
  font-weight: 600;
  letter-spacing: 0.01em;
  color: var(--c-fog);
}

.page-about .rule__text {
  margin: 0;
  max-width: 48ch;
  color: var(--c-body);
  line-height: 1.78;
}

/* ---------- 02 边界 ---------- */

.page-about .boundary {
  display: grid;
  grid-template-columns: 1fr;
  gap: 18px;
}

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

.page-about .boundary__col {
  padding: clamp(18px, 2.4vw, 26px) 0 clamp(18px, 2.4vw, 26px) clamp(16px, 2.2vw, 24px);
  border-left: 2px solid var(--c-line);
  border-radius: 0 var(--radius-md) var(--radius-md) 0;
  background: linear-gradient(90deg, rgba(13, 22, 38, 0.85), rgba(6, 10, 18, 0) 92%);
}

.page-about .boundary__col--do {
  border-left-color: rgba(61, 224, 208, 0.65);
}

.page-about .boundary__col--dont {
  border-left-color: rgba(255, 122, 47, 0.6);
}

.page-about .boundary__title {
  margin: 0 0 14px;
  font-size: 0.98rem;
  font-weight: 600;
  letter-spacing: 0.04em;
  color: var(--c-fog);
}

.page-about .boundary__list {
  margin: 0;
  padding-left: 1.1em;
  display: grid;
  gap: 10px;
  max-width: 40ch;
  color: var(--c-body);
  line-height: 1.72;
}

.page-about .boundary__list li::marker {
  color: var(--c-cyan);
}

.page-about .boundary__col--dont .boundary__list li::marker {
  color: var(--c-dawn);
}

/* ---------- 03 场景 ---------- */

.page-about .scene-list {
  list-style: none;
  margin: 0;
  padding: 0;
  display: grid;
}

.page-about .scene {
  position: relative;
  padding: 22px 0 22px 26px;
  border-left: 1px dashed var(--about-dash);
}

.page-about .scene:last-child {
  padding-bottom: 6px;
  border-left-color: transparent;
}

.page-about .scene::before {
  content: "";
  position: absolute;
  left: -5px;
  top: 30px;
  width: 9px;
  height: 9px;
  border-radius: 50%;
  background: var(--c-night);
  border: 2px solid var(--c-dawn);
}

.page-about .scene:last-child::before {
  background: var(--c-pulse);
  border-color: var(--c-pulse);
  box-shadow: 0 0 0 6px rgba(200, 244, 91, 0.12);
}

.page-about .scene__time {
  margin: 0 0 6px;
  font-size: 0.82rem;
  letter-spacing: 0.08em;
  color: var(--c-pulse);
}

.page-about .scene__title {
  margin: 0 0 8px;
  font-size: 1.08rem;
  font-weight: 600;
  color: var(--c-fog);
}

.page-about .scene__text {
  margin: 0 0 10px;
  max-width: 48ch;
  color: var(--c-body);
  line-height: 1.78;
}

.page-about .scene__where {
  margin: 0;
  font-size: 0.86rem;
}

.page-about .scene__where a {
  color: var(--c-cyan);
  text-decoration: none;
  border-bottom: 1px solid rgba(61, 224, 208, 0.32);
  transition: border-color 0.22s var(--ease);
}

.page-about .scene__where a:hover {
  border-bottom-color: var(--c-cyan);
}

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

/* ---------- 04 沿革 ---------- */

.page-about .version-track {
  list-style: none;
  margin: 0 0 clamp(24px, 3.5vw, 40px);
  padding: 0;
  display: grid;
  gap: 0;
}

.page-about .version {
  position: relative;
  padding: 0 0 26px 24px;
  border-left: 1px dashed var(--about-dash);
  transition: background-color 0.24s var(--ease);
}

.page-about .version:last-child {
  padding-bottom: 0;
  border-left-color: transparent;
}

.page-about .version::before {
  content: "";
  position: absolute;
  left: -6px;
  top: 4px;
  width: 11px;
  height: 11px;
  border-radius: 50%;
  background: var(--c-night);
  border: 2px solid var(--c-cyan);
  transition: box-shadow 0.24s var(--ease);
}

.page-about .version:hover::before {
  box-shadow: 0 0 0 5px rgba(61, 224, 208, 0.14);
}

.page-about .version__node {
  display: inline-flex;
  align-items: center;
  min-height: 26px;
  padding: 3px 12px;
  margin-bottom: 9px;
  border-radius: var(--radius-pill);
  font-size: 0.78rem;
  letter-spacing: 0.06em;
  color: var(--c-night);
  background: var(--c-cyan);
}

.page-about .version:last-child .version__node {
  background: var(--c-dawn);
  color: #1a0c04;
}

.page-about .version__title {
  margin: 0 0 6px;
  font-size: 1rem;
  font-weight: 600;
  color: var(--c-fog);
}

.page-about .version__note {
  margin: 0;
  max-width: 36ch;
  font-size: 0.9rem;
  line-height: 1.72;
  color: var(--c-mute);
  transition: color 0.24s var(--ease);
}

.page-about .version:hover .version__note {
  color: var(--c-body);
}

@media (min-width: 860px) {
  .page-about .version-track {
    grid-template-columns: repeat(4, minmax(0, 1fr));
    gap: clamp(14px, 2vw, 26px);
  }

  .page-about .version {
    padding: 30px 0 0 0;
    border-left: 0;
    border-top: 1px dashed var(--about-dash);
  }

  .page-about .version:last-child {
    border-top-color: transparent;
    padding-bottom: 0;
  }

  .page-about .version::before {
    left: 0;
    top: -6px;
  }

  .page-about .version__note {
    max-width: none;
  }
}

/* ---------- 05 团队与校对 ---------- */

.page-about .stat-row {
  display: grid;
  grid-template-columns: 1fr;
  gap: 1px;
  margin: 0 0 clamp(22px, 3vw, 34px);
  border-radius: var(--radius-lg);
  overflow: hidden;
  background: rgba(30, 42, 66, 0.75);
}

@media (min-width: 700px) {
  .page-about .stat-row {
    grid-template-columns: repeat(3, minmax(0, 1fr));
  }
}

.page-about .stat-row .stat {
  padding: 20px clamp(16px, 2vw, 24px);
  background: linear-gradient(180deg, rgba(13, 22, 38, 0.96), rgba(6, 10, 18, 0.96));
}

.page-about .stat-row .stat__num {
  color: var(--c-pulse);
}

.page-about .checkflow {
  list-style: none;
  margin: 0 0 clamp(22px, 3vw, 34px);
  padding: 0;
  display: grid;
  gap: 0;
}

.page-about .checkflow li {
  display: flex;
  flex-wrap: wrap;
  align-items: baseline;
  gap: 12px;
  padding: 13px 0;
  border-bottom: 1px solid rgba(30, 42, 66, 0.7);
  color: var(--c-body);
  line-height: 1.72;
}

.page-about .checkflow li:first-child {
  border-top: 1px solid rgba(30, 42, 66, 0.7);
}

.page-about .checkflow li span {
  font-size: 0.82rem;
  letter-spacing: 0.06em;
  color: var(--c-cyan);
}

/* ---------- 06 问答 ---------- */

.page-about .qa-list {
  display: grid;
  gap: 10px;
}

.page-about .qa {
  border-radius: var(--radius-md);
  border: 1px solid rgba(30, 42, 66, 0.8);
  background: rgba(13, 22, 38, 0.72);
  overflow: hidden;
  transition: border-color 0.24s var(--ease), background-color 0.24s var(--ease);
}

.page-about .qa[open] {
  border-color: rgba(61, 224, 208, 0.38);
  background: rgba(13, 22, 38, 0.94);
}

.page-about .qa__summary {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 16px;
  min-height: 54px;
  padding: 14px 18px;
  cursor: pointer;
  list-style: none;
  font-size: 1rem;
  font-weight: 500;
  color: var(--c-fog);
}

.page-about .qa__summary::-webkit-details-marker {
  display: none;
}

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

.page-about .qa__icon {
  position: relative;
  flex: none;
  width: 18px;
  height: 18px;
}

.page-about .qa__icon::before,
.page-about .qa__icon::after {
  content: "";
  position: absolute;
  border-radius: 2px;
  background: var(--c-cyan);
  transition: transform 0.24s var(--ease), opacity 0.24s var(--ease);
}

.page-about .qa__icon::before {
  top: 8px;
  left: 0;
  width: 18px;
  height: 2px;
}

.page-about .qa__icon::after {
  top: 0;
  left: 8px;
  width: 2px;
  height: 18px;
}

.page-about .qa[open] .qa__icon::after {
  opacity: 0;
  transform: scaleY(0);
}

.page-about .qa__body {
  padding: 0 18px 18px;
  color: var(--c-body);
  line-height: 1.8;
}

.page-about .qa__body p {
  margin: 0;
  max-width: 56ch;
}

.page-about .qa__body a {
  color: var(--c-cyan);
  text-decoration: none;
  border-bottom: 1px solid rgba(61, 224, 208, 0.32);
  transition: border-color 0.22s var(--ease);
}

.page-about .qa__body a:hover {
  border-bottom-color: var(--c-cyan);
}

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

/* ---------- 减少动效 ---------- */

@media (prefers-reduced-motion: reduce) {
  .page-about .rail-index__link,
  .page-about .rule,
  .page-about .version__note,
  .page-about .version::before,
  .page-about .qa,
  .page-about .qa__icon::before,
  .page-about .qa__icon::after {
    transition: none;
  }

  .page-about .rail-index__link:hover {
    transform: none;
  }

  .page-about .rule:hover {
    padding-left: 0;
  }
}
<<<END>>>