.page-about {
  --about-rail: 200px;
  --about-measure: 33rem;
  background: var(--deep-900);
  color: var(--paper-100);
  overflow-x: clip;
}

.page-about .about-h2 {
  font-family: var(--font-display);
  font-weight: 800;
  letter-spacing: -0.015em;
  font-size: clamp(1.55rem, 4.4vw, 2.5rem);
  line-height: 1.22;
  margin: 0.45em 0 0.6em;
  color: var(--paper-100);
}

.page-about .section--paper .about-h2 {
  color: var(--ink-900);
}

.page-about .section--paper {
  background: var(--paper-100);
  color: var(--ink-900);
}

/* ---------- 面包屑 ---------- */
.page-about .crumbs ol {
  list-style: none;
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 6px;
  margin: 0 0 clamp(16px, 3vw, 26px);
  padding: 0;
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.04em;
  color: var(--mist-400);
}

.page-about .crumbs a {
  color: var(--mist-400);
  text-decoration: none;
  border-bottom: 1px solid transparent;
  transition: color 0.18s var(--ease), border-color 0.18s var(--ease);
}

.page-about .crumbs a:hover,
.page-about .crumbs a:focus-visible {
  color: var(--cyan-400);
  border-bottom-color: var(--cyan-400);
}

.page-about .crumbs li + li::before {
  content: "/";
  margin-right: 6px;
  color: var(--deep-500);
}

/* ---------- 首屏 ---------- */
.page-about .about-hero {
  position: relative;
  isolation: isolate;
  padding: clamp(22px, 4vw, 44px) 0 clamp(56px, 8vw, 104px);
}

.page-about .about-hero::before {
  content: "";
  position: absolute;
  inset: 0;
  z-index: -2;
  background:
    radial-gradient(90% 70% at 84% -12%, rgba(43, 231, 206, 0.2), rgba(4, 18, 31, 0) 62%),
    radial-gradient(70% 60% at 8% 0%, rgba(18, 58, 85, 0.85), rgba(4, 18, 31, 0) 66%),
    linear-gradient(180deg, rgba(10, 36, 56, 0.92) 0%, rgba(4, 18, 31, 0) 74%);
}

.page-about .about-hero::after {
  content: "";
  position: absolute;
  inset: 0;
  z-index: -1;
  background-image:
    linear-gradient(rgba(140, 163, 180, 0.09) 1px, transparent 1px),
    linear-gradient(90deg, rgba(140, 163, 180, 0.09) 1px, transparent 1px);
  background-size: 72px 72px;
  -webkit-mask-image: linear-gradient(180deg, rgba(0, 0, 0, 0.9), transparent 80%);
  mask-image: linear-gradient(180deg, rgba(0, 0, 0, 0.9), transparent 80%);
  pointer-events: none;
}

.page-about .about-hero h1 {
  font-family: var(--font-display);
  font-weight: 900;
  letter-spacing: -0.02em;
  font-size: clamp(2.05rem, 7.2vw, 4.4rem);
  line-height: 1.08;
  margin: 0.4em 0 0.5em;
  color: var(--paper-100);
}

.page-about .about-hero .lede {
  max-width: 40rem;
  font-size: clamp(1rem, 2.4vw, 1.12rem);
  line-height: 1.8;
  color: rgba(246, 243, 234, 0.78);
  margin: 0;
}

.page-about .about-hero__facts {
  list-style: none;
  margin: clamp(24px, 4vw, 40px) 0 0;
  padding: 0;
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
}

.page-about .about-hero__facts li {
  font-family: var(--font-mono);
  font-size: 12.5px;
  letter-spacing: 0.04em;
  color: var(--cyan-400);
  border: 1px solid var(--deep-500);
  background: rgba(10, 36, 56, 0.6);
  padding: 7px 12px;
}

/* ---------- 缘起 ---------- */
.page-about .about-origin {
  padding: clamp(48px, 7vw, 96px) 0;
}

.page-about .about-origin__grid {
  display: grid;
  gap: clamp(24px, 4vw, 48px);
}

.page-about .about-origin__main {
  max-width: 40rem;
}

.page-about .about-origin__main p:not(.eyebrow) {
  font-size: 16.5px;
  line-height: 1.82;
  color: rgba(246, 243, 234, 0.76);
  margin: 0 0 1.1em;
}

.page-about .origin-note {
  border: 1px solid var(--deep-500);
  border-top: 2px solid var(--cyan-400);
  background: var(--deep-700);
  padding: 20px 20px 22px;
  box-shadow: 6px 6px 0 0 rgba(43, 231, 206, 0.08);
}

.page-about .origin-note__title {
  margin: 0 0 14px;
  font-size: 12px;
  letter-spacing: 0.06em;
  color: var(--cyan-400);
}

.page-about .origin-note__list {
  list-style: none;
  margin: 0;
  padding: 0;
  display: grid;
  gap: 12px;
}

.page-about .origin-note__list li {
  display: flex;
  gap: 10px;
  align-items: baseline;
  font-size: 14.5px;
  line-height: 1.65;
  color: rgba(246, 243, 234, 0.85);
  padding-bottom: 12px;
  border-bottom: 1px dashed var(--deep-500);
}

.page-about .origin-note__list li:last-child {
  border-bottom: 0;
  padding-bottom: 0;
}

.page-about .origin-note__list span {
  color: var(--mist-400);
  font-size: 11.5px;
  flex: none;
}

/* ---------- 发展脉络 ---------- */
.page-about .about-timeline {
  position: relative;
  isolation: isolate;
  overflow: hidden;
  padding: clamp(52px, 8vw, 108px) 0;
  background: var(--deep-700);
}

.page-about .about-timeline__bg {
  position: absolute;
  inset: 0;
  z-index: 0;
  opacity: 0.17;
  pointer-events: none;
  -webkit-mask-image: radial-gradient(72% 66% at 62% 26%, #000, transparent 76%);
  mask-image: radial-gradient(72% 66% at 62% 26%, #000, transparent 76%);
}

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

.page-about .about-timeline__grid {
  position: relative;
  z-index: 1;
  display: grid;
  gap: clamp(24px, 4vw, 48px);
}

.page-about .about-timeline__lede {
  max-width: 34rem;
  font-size: 16px;
  line-height: 1.8;
  color: rgba(246, 243, 234, 0.72);
  margin: 0 0 clamp(28px, 4vw, 44px);
}

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

.page-about .about-rail__title {
  font-size: 11.5px;
  letter-spacing: 0.08em;
  color: var(--mist-400);
  margin: 0 0 14px;
}

.page-about .about-rail__list {
  list-style: none;
  margin: 0;
  padding: 0;
  border-left: 1px solid var(--deep-500);
}

.page-about .about-rail__link {
  display: flex;
  gap: 10px;
  align-items: baseline;
  margin-left: -1px;
  padding: 10px 0 10px 14px;
  border-left: 2px solid transparent;
  color: var(--mist-400);
  text-decoration: none;
  font-size: 13.5px;
  line-height: 1.4;
  transition: color 0.18s var(--ease), border-color 0.18s var(--ease);
}

.page-about .about-rail__link span {
  font-size: 11.5px;
  color: var(--deep-500);
  transition: color 0.18s var(--ease);
}

.page-about .about-rail__link:hover,
.page-about .about-rail__link:focus-visible {
  color: var(--cyan-400);
  border-left-color: var(--cyan-400);
}

.page-about .about-rail__link:hover span,
.page-about .about-rail__link:focus-visible span {
  color: var(--cyan-700);
}

.page-about .timeline {
  list-style: none;
  margin: 0;
  padding: 0;
  display: grid;
  gap: clamp(18px, 3vw, 28px);
}

.page-about .timeline__item {
  position: relative;
  padding: 20px 0 0;
  border-top: 1px solid var(--deep-500);
  scroll-margin-top: 110px;
}

.page-about .timeline__item::before {
  content: "";
  position: absolute;
  top: -5px;
  left: 0;
  width: 9px;
  height: 9px;
  border-radius: 50%;
  background: var(--cyan-400);
  box-shadow: 0 0 0 4px rgba(43, 231, 206, 0.16);
}

.page-about .timeline__idx {
  margin: 0 0 8px;
  font-size: 11.5px;
  letter-spacing: 0.08em;
  color: var(--cyan-400);
}

.page-about .timeline__title {
  font-family: var(--font-display);
  font-weight: 700;
  font-size: 1.08rem;
  line-height: 1.35;
  margin: 0 0 8px;
  color: var(--paper-100);
}

.page-about .timeline__text {
  margin: 0;
  font-size: 14.5px;
  line-height: 1.78;
  color: rgba(246, 243, 234, 0.7);
}

/* ---------- 职能分工 ---------- */
.page-about .about-teams {
  padding: clamp(52px, 8vw, 108px) 0;
}

.page-about .about-teams__lede,
.page-about .about-rules__lede,
.page-about .about-scale__lede,
.page-about .about-loop__text {
  max-width: 34rem;
  font-size: 16px;
  line-height: 1.8;
  color: rgba(246, 243, 234, 0.72);
  margin: 0 0 clamp(26px, 4vw, 40px);
}

.page-about .teams__layout {
  display: grid;
  gap: clamp(26px, 4vw, 48px);
}

.page-about .teams__list {
  display: grid;
  gap: clamp(18px, 3vw, 26px);
}

.page-about .filters {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
}

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

.page-about .team-card {
  position: relative;
  background: var(--deep-700);
  border: 1px solid var(--deep-500);
  border-left: 2px solid var(--cyan-700);
  padding: 18px 18px 20px;
  transition: border-color 0.18s var(--ease), background 0.18s var(--ease);
}

.page-about .team-card:hover,
.page-about .team-card:focus-within {
  border-color: var(--cyan-400);
  background: var(--deep-500);
}

.page-about .team-card__idx {
  margin: 0 0 8px;
  font-size: 11.5px;
  letter-spacing: 0.08em;
  color: var(--mist-400);
}

.page-about .team-card__title {
  font-family: var(--font-display);
  font-weight: 700;
  font-size: 1.12rem;
  margin: 0 0 8px;
  color: var(--paper-100);
}

.page-about .team-card__text {
  margin: 0 0 14px;
  font-size: 14.5px;
  line-height: 1.78;
  color: rgba(246, 243, 234, 0.74);
}

.page-about .team-card__list {
  list-style: none;
  margin: 0;
  padding: 0;
  display: grid;
  gap: 7px;
  border-top: 1px solid var(--deep-500);
  padding-top: 12px;
}

.page-about .team-card__list li {
  position: relative;
  padding-left: 16px;
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.03em;
  color: var(--cyan-400);
  line-height: 1.6;
}

.page-about .team-card__list li::before {
  content: "";
  position: absolute;
  left: 0;
  top: 0.62em;
  width: 6px;
  height: 1px;
  background: var(--cyan-700);
}

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

.page-about .teams__figure .media-frame {
  border: 1px solid var(--deep-500);
}

.page-about .teams__figure .media-frame__cap {
  display: block;
  margin-top: 10px;
  font-size: 11.5px;
  letter-spacing: 0.04em;
  color: var(--mist-400);
}

/* ---------- 服务准则 ---------- */
.page-about .about-rules {
  padding: clamp(52px, 8vw, 108px) 0;
}

.page-about .about-rules__lede {
  color: #4a5763;
}

.page-about .rules {
  list-style: none;
  margin: 0;
  padding: 0;
  display: grid;
  gap: 16px;
}

.page-about .rules__item {
  background: #fffdf6;
  border: 1px solid var(--paper-300);
  border-top: 3px solid var(--cyan-700);
  padding: 20px 20px 22px;
  box-shadow: 5px 5px 0 0 rgba(228, 223, 210, 0.85);
}

.page-about .rules__num {
  margin: 0 0 10px;
  font-size: 11.5px;
  letter-spacing: 0.08em;
  color: var(--cyan-700);
}

.page-about .rules__title {
  font-family: var(--font-display);
  font-weight: 700;
  font-size: 1.12rem;
  line-height: 1.35;
  margin: 0 0 10px;
  color: var(--ink-900);
}

.page-about .rules__text {
  margin: 0 0 14px;
  font-size: 15px;
  line-height: 1.78;
  color: #3b4753;
}

.page-about .rules__result {
  margin: 0;
  padding-top: 12px;
  border-top: 1px dashed var(--paper-300);
  font-size: 12px;
  letter-spacing: 0.05em;
  color: var(--cyan-700);
}

/* ---------- 覆盖与规模 ---------- */
.page-about .about-scale {
  padding: clamp(52px, 8vw, 108px) 0;
  background: var(--deep-700);
}

.page-about .about-scale__grid {
  display: grid;
  gap: clamp(28px, 4vw, 56px);
}

.page-about .scale-cards {
  list-style: none;
  margin: 0;
  padding: 0 0 0 4px;
  display: grid;
  gap: 12px;
}

.page-about .scale-card {
  position: relative;
  background: var(--paper-100);
  color: var(--ink-900);
  border: 1px solid var(--paper-300);
  padding: 14px 16px 16px;
  box-shadow: 4px 4px 0 0 rgba(4, 18, 31, 0.55);
}

.page-about .scale-card:nth-child(2) {
  transform: translateX(8px);
}

.page-about .scale-card:nth-child(3) {
  transform: translateX(16px);
}

.page-about .scale-card:nth-child(4) {
  transform: translateX(24px);
}

.page-about .scale-card__num {
  margin: 0;
  font-size: clamp(1.6rem, 5vw, 2.1rem);
  font-weight: 700;
  line-height: 1.05;
  color: var(--cyan-700);
}

.page-about .scale-card__label {
  margin: 4px 0 6px;
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.05em;
  color: var(--ink-900);
}

.page-about .scale-card__text {
  margin: 0;
  font-size: 13.5px;
  line-height: 1.7;
  color: #495663;
}

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

.page-about .about-scale__figure .media-frame {
  border: 1px solid var(--deep-500);
}

.page-about .about-scale__figure .media-frame__cap {
  display: block;
  margin-top: 10px;
  font-size: 11.5px;
  letter-spacing: 0.04em;
  color: var(--mist-400);
}

/* ---------- 回访与改进 ---------- */
.page-about .about-loop {
  padding: clamp(52px, 8vw, 108px) 0;
}

.page-about .about-loop__grid {
  display: grid;
  gap: clamp(28px, 4vw, 56px);
}

.page-about .about-loop__lead {
  max-width: 34rem;
}

.page-about .loop-score {
  display: inline-flex;
  flex-direction: column;
  gap: 4px;
  border: 1px solid var(--deep-500);
  border-left: 3px solid var(--cyan-400);
  background: rgba(10, 36, 56, 0.7);
  padding: 16px 22px 18px;
}

.page-about .loop-score__num {
  margin: 0;
  font-size: clamp(2rem, 6vw, 2.9rem);
  font-weight: 700;
  line-height: 1;
  color: var(--cyan-400);
}

.page-about .loop-score__num span {
  font-size: 0.55em;
  margin-left: 2px;
}

.page-about .loop-score__label {
  margin: 0;
  font-size: 12.5px;
  letter-spacing: 0.03em;
  color: var(--mist-400);
}

.page-about .loop-steps {
  list-style: none;
  margin: 0;
  padding: 0;
  display: grid;
  gap: 0;
  border-left: 1px solid var(--deep-500);
}

.page-about .loop-step {
  position: relative;
  padding: 0 0 26px 22px;
}

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

.page-about .loop-step::before {
  content: "";
  position: absolute;
  left: -4.5px;
  top: 6px;
  width: 8px;
  height: 8px;
  border-radius: 50%;
  background: var(--deep-900);
  border: 1px solid var(--cyan-700);
}

.page-about .loop-step__num {
  margin: 0 0 6px;
  font-size: 11.5px;
  letter-spacing: 0.08em;
  color: var(--cyan-400);
}

.page-about .loop-step__title {
  font-family: var(--font-display);
  font-weight: 700;
  font-size: 1.05rem;
  margin: 0 0 6px;
  color: var(--paper-100);
}

.page-about .loop-step__text {
  margin: 0;
  font-size: 14.5px;
  line-height: 1.78;
  color: rgba(246, 243, 234, 0.72);
}

/* ---------- 下一步 ---------- */
.page-about .about-next {
  padding: clamp(44px, 7vw, 88px) 0 clamp(56px, 8vw, 110px);
  border-top: 1px solid var(--deep-500);
  background: linear-gradient(180deg, rgba(10, 36, 56, 0.55), rgba(4, 18, 31, 0));
}

.page-about .about-next__grid {
  display: grid;
  gap: 12px;
  margin-top: clamp(20px, 3vw, 32px);
}

.page-about .next-link {
  display: grid;
  gap: 6px;
  padding: 18px 18px 20px;
  border: 1px solid var(--deep-500);
  background: rgba(10, 36, 56, 0.45);
  text-decoration: none;
  transition: border-color 0.18s var(--ease), background 0.18s var(--ease);
}

.page-about .next-link:hover,
.page-about .next-link:focus-visible {
  border-color: var(--orange-500);
  background: rgba(10, 36, 56, 0.85);
}

.page-about .next-link__idx {
  font-size: 11.5px;
  letter-spacing: 0.08em;
  color: var(--cyan-400);
}

.page-about .next-link__title {
  font-family: var(--font-display);
  font-weight: 700;
  font-size: 1.1rem;
  color: var(--paper-100);
}

.page-about .next-link__text {
  font-size: 14px;
  line-height: 1.7;
  color: rgba(246, 243, 234, 0.7);
}

/* ---------- 响应式 ---------- */
@media (min-width: 640px) {
  .page-about .team-cards {
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }

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

@media (min-width: 760px) {
  .page-about .timeline {
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }

  .page-about .rules {
    grid-template-columns: repeat(2, minmax(0, 1fr));
    gap: 18px 24px;
  }

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

@media (min-width: 900px) {
  .page-about .about-origin__grid {
    grid-template-columns: minmax(0, 7fr) minmax(0, 4fr);
    align-items: start;
  }

  .page-about .teams__layout {
    grid-template-columns: minmax(0, 1fr) 340px;
    align-items: start;
  }

  .page-about .about-scale__grid {
    grid-template-columns: minmax(0, 1fr) minmax(0, 0.92fr);
    align-items: center;
  }

  .page-about .about-loop__grid {
    grid-template-columns: minmax(0, 5fr) minmax(0, 6fr);
    align-items: start;
  }
}

@media (min-width: 1024px) {
  .page-about .about-timeline__grid {
    grid-template-columns: var(--about-rail) minmax(0, 1fr);
    gap: clamp(28px, 4vw, 56px);
  }

  .page-about .about-rail {
    display: block;
    position: sticky;
    top: 96px;
    align-self: start;
  }

  .page-about .timeline {
    grid-template-columns: repeat(4, minmax(0, 1fr));
    gap: 0 20px;
  }

  .page-about .timeline__item {
    padding-top: 22px;
  }

  .page-about .timeline__text {
    font-size: 13.8px;
    line-height: 1.72;
  }

  .page-about .scale-card:nth-child(2) {
    transform: translateX(14px);
  }

  .page-about .scale-card:nth-child(3) {
    transform: translateX(28px);
  }

  .page-about .scale-card:nth-child(4) {
    transform: translateX(42px);
  }

  .page-about .scale-cards {
    padding-right: 42px;
  }
}

@media (prefers-reduced-motion: reduce) {
  .page-about .team-card,
  .page-about .next-link,
  .page-about .about-rail__link,
  .page-about .crumbs a {
    transition: none;
  }
}