.page-about {
  --about-line: rgba(157, 180, 198, 0.16);
  --about-line-soft: rgba(157, 180, 198, 0.09);
  --about-glow: rgba(47, 227, 208, 0.14);
  background: var(--abyss);
  color: var(--mist);
  overflow-x: hidden;
}

/* ---------- 首屏 ---------- */
.page-about .about-hero {
  position: relative;
  overflow: hidden;
  padding: 20px 0 44px;
  border-bottom: 1px solid var(--about-line);
}

.page-about .about-hero > .container {
  position: relative;
  z-index: 1;
}

.page-about .about-hero__art {
  position: absolute;
  top: -12%;
  right: -30%;
  width: 145%;
  max-width: none;
  height: auto;
  opacity: 0.32;
  z-index: 0;
  pointer-events: none;
  -webkit-mask-image: radial-gradient(70% 70% at 72% 42%, #000 8%, transparent 74%);
  mask-image: radial-gradient(70% 70% at 72% 42%, #000 8%, transparent 74%);
}

.page-about .about-hero__grid {
  margin-top: 22px;
  row-gap: 30px;
}

.page-about .about-hero .display-title {
  font-family: var(--font-display);
  font-size: clamp(28px, 7vw, 60px);
  font-weight: 900;
  line-height: 1.14;
  letter-spacing: -0.02em;
  margin: 8px 0 18px;
  color: var(--mist);
}

.page-about .about-hero .lede {
  max-width: 34em;
  font-size: 16px;
  line-height: 1.78;
  color: var(--mist);
  opacity: 0.92;
}

.page-about .about-hero__rail {
  border-left: 1px solid var(--about-line);
  padding-left: 16px;
}

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

.page-about .hero-facts li {
  display: flex;
  align-items: baseline;
  gap: 10px;
  flex-wrap: wrap;
}

.page-about .hero-facts .n {
  font-family: var(--font-mono);
  font-size: 20px;
  font-weight: 500;
  color: var(--cyan);
  letter-spacing: -0.01em;
}

.page-about .hero-facts .n em {
  font-style: normal;
  font-size: 13px;
  color: var(--slate);
  margin-left: 2px;
}

.page-about .hero-facts .t {
  font-size: 13px;
  color: var(--slate);
  letter-spacing: 0.04em;
}

/* ---------- 章节通用 ---------- */
.page-about .about-sec {
  padding: 48px 0;
  border-top: 1px solid var(--about-line-soft);
}

.page-about .about-sec:first-of-type {
  border-top: 0;
}

.page-about .about-sec__row {
  row-gap: 22px;
  align-items: start;
}

.page-about .sec-no {
  font-family: var(--font-mono);
  font-size: 13px;
  font-weight: 500;
  letter-spacing: 0.18em;
  color: var(--cyan);
  margin: 0 0 10px;
}

.page-about .rail-note {
  font-size: 12px;
  letter-spacing: 0.16em;
  color: var(--slate);
  margin: 0;
}

.page-about .section-title {
  font-family: var(--font-display);
  font-size: clamp(23px, 4vw, 38px);
  font-weight: 900;
  line-height: 1.28;
  letter-spacing: -0.01em;
  margin: 0 0 18px;
  color: var(--mist);
}

.page-about .about-sec__body p {
  max-width: 36em;
  font-size: 16px;
  line-height: 1.8;
  margin: 0 0 16px;
  color: var(--mist);
  opacity: 0.92;
}

.page-about .about-sec__body a {
  color: var(--cyan);
  text-decoration: none;
  border-bottom: 1px solid rgba(47, 227, 208, 0.4);
  transition: border-color 180ms var(--ease), color 180ms var(--ease);
}

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

.page-about .sec-note {
  font-size: 14px !important;
  color: var(--slate) !important;
  border-left: 2px solid var(--about-glow);
  padding-left: 14px;
  margin-top: 22px !important;
}

/* ---------- 服务清单 ---------- */
.page-about .svc-list {
  list-style: none;
  margin: 26px 0 8px;
  padding: 0;
  border-top: 1px solid var(--about-line);
}

.page-about .svc {
  display: grid;
  grid-template-columns: 40px 1fr;
  gap: 10px 14px;
  padding: 18px 0;
  border-bottom: 1px solid var(--about-line);
}

.page-about .svc__no {
  font-family: var(--font-mono);
  font-size: 13px;
  color: var(--slate);
  padding-top: 4px;
}

.page-about .svc__main h3 {
  font-size: 17px;
  font-weight: 700;
  margin: 0 0 6px;
  color: var(--paper);
  letter-spacing: 0.01em;
}

.page-about .svc__main p {
  font-size: 15px;
  line-height: 1.75;
  margin: 0;
  color: var(--slate);
  max-width: 34em;
}

.page-about .svc .chip {
  grid-column: 2;
  justify-self: start;
  font-size: 12px;
}

/* ---------- 时间轴 ---------- */
.page-about .tl-art {
  display: block;
  width: 100%;
  max-width: 100%;
  height: auto;
  object-fit: cover;
  border-radius: var(--radius-md);
  margin: 6px 0 30px;
  opacity: 0.9;
  border: 1px solid var(--about-line);
}

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

.page-about .tl__item {
  position: relative;
  padding-left: 26px;
  padding-bottom: 12px;
}

.page-about .tl__item::before {
  content: "";
  position: absolute;
  left: 5px;
  top: 22px;
  bottom: -6px;
  width: 1px;
  background: linear-gradient(180deg, var(--about-line), transparent);
}

.page-about .tl__item:last-child::before {
  display: none;
}

.page-about .tl__item::after {
  content: "";
  position: absolute;
  left: 0;
  top: 12px;
  width: 11px;
  height: 11px;
  border-radius: 50%;
  border: 1px solid var(--slate);
  background: var(--abyss);
  transition: border-color 220ms var(--ease), background 220ms var(--ease);
}

.page-about .tl__item:nth-child(3)::after,
.page-about .tl__item:nth-child(4)::after {
  border-color: rgba(47, 227, 208, 0.55);
}

.page-about .tl__item:nth-child(5)::after {
  border-color: var(--cyan);
  background: var(--cyan);
  box-shadow: 0 0 0 4px rgba(47, 227, 208, 0.14);
}

.page-about .tl__node {
  border-bottom: 1px dashed transparent;
}

.page-about .tl__summary {
  display: flex;
  align-items: baseline;
  gap: 12px;
  padding: 6px 0 10px;
  cursor: pointer;
  list-style: none;
}

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

.page-about .tl__year {
  font-family: var(--font-mono);
  font-size: 14px;
  font-weight: 500;
  color: var(--gold);
  min-width: 52px;
}

.page-about .tl__title {
  font-size: 16px;
  font-weight: 700;
  color: var(--mist);
  flex: 1;
}

.page-about .tl__mark {
  position: relative;
  width: 14px;
  height: 14px;
  flex: none;
  color: var(--cyan);
  transition: transform 220ms var(--ease);
}

.page-about .tl__mark::before,
.page-about .tl__mark::after {
  content: "";
  position: absolute;
  background: currentColor;
  left: 50%;
  top: 50%;
}

.page-about .tl__mark::before {
  width: 12px;
  height: 1px;
  transform: translate(-50%, -50%);
}

.page-about .tl__mark::after {
  width: 1px;
  height: 12px;
  transform: translate(-50%, -50%);
}

.page-about .tl__node[open] .tl__mark {
  transform: rotate(45deg);
}

.page-about .tl__node[open] .tl__title {
  color: var(--cyan);
}

.page-about .tl__desc {
  font-size: 15px;
  line-height: 1.75;
  color: var(--slate);
  margin: 0 0 14px;
  max-width: 34em;
}

/* ---------- 团队 ---------- */
.page-about .team {
  display: grid;
  grid-template-columns: 1fr;
  gap: 2px;
  margin-top: 28px;
  border-top: 1px solid var(--about-line);
}

.page-about .team__item {
  padding: 18px 0 16px;
  border-bottom: 1px solid var(--about-line);
}

.page-about .team__num {
  font-family: var(--font-mono);
  font-size: 30px;
  font-weight: 500;
  line-height: 1;
  color: var(--cyan);
  margin: 0 0 8px;
}

.page-about .team__label {
  font-size: 15px;
  font-weight: 700;
  color: var(--paper);
  margin: 0 0 4px;
}

.page-about .team__desc {
  font-size: 14px;
  line-height: 1.7;
  color: var(--slate);
  margin: 0;
  max-width: none !important;
}

/* ---------- 覆盖范围 ---------- */
.page-about .cov {
  display: grid;
  gap: 22px;
  margin-bottom: 26px;
}

.page-about .cov__fig {
  margin: 0;
  border-radius: var(--radius-lg);
  overflow: hidden;
  border: 1px solid var(--about-line);
  background: var(--tide);
}

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

.page-about .stats {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 18px 16px;
}

.page-about .stat {
  position: relative;
  padding: 14px 0 8px;
  border-top: 1px solid var(--about-line);
}

.page-about .stat__num {
  display: block;
  font-family: var(--font-mono);
  font-size: 28px;
  font-weight: 500;
  line-height: 1.1;
  color: var(--paper);
  letter-spacing: -0.01em;
}

.page-about .stat__num em {
  font-style: normal;
  font-size: 13px;
  color: var(--cyan);
  margin-left: 3px;
}

.page-about .stat__label {
  display: block;
  margin-top: 6px;
  font-size: 13px;
  color: var(--slate);
  letter-spacing: 0.03em;
}

.page-about .stat__hint {
  position: absolute;
  left: 0;
  top: 100%;
  z-index: 4;
  width: 200px;
  padding: 9px 11px;
  font-size: 12px;
  line-height: 1.6;
  color: var(--mist);
  background: var(--ink);
  border: 1px solid var(--line-strong);
  border-radius: var(--radius-md);
  opacity: 0;
  transform: translateY(-5px);
  transition: opacity 200ms var(--ease), transform 200ms var(--ease);
  pointer-events: none;
}

.page-about .stat:hover .stat__hint,
.page-about .stat:focus .stat__hint,
.page-about .stat:focus-within .stat__hint {
  opacity: 1;
  transform: translateY(0);
}

/* ---------- 质量与响应 ---------- */
.page-about .q-list {
  list-style: none;
  margin: 26px 0 0;
  padding: 0;
  display: grid;
  gap: 2px;
}

.page-about .q {
  display: grid;
  gap: 10px;
  padding: 16px 0;
  border-bottom: 1px solid var(--about-line);
}

.page-about .q .chip {
  justify-self: start;
  font-family: var(--font-mono);
  font-size: 12px;
}

.page-about .q p {
  margin: 0;
  font-size: 15px;
  line-height: 1.75;
  color: var(--slate);
  max-width: 34em;
}

/* ---------- 合作生态 ---------- */
.page-about .partners {
  display: grid;
  gap: 20px;
  margin: 26px 0 6px;
}

.page-about .partner {
  padding-left: 16px;
  border-left: 1px solid var(--about-line);
}

.page-about .partner__num {
  font-family: var(--font-mono);
  font-size: 26px;
  font-weight: 500;
  color: var(--coral);
  margin: 0 0 6px;
  line-height: 1;
}

.page-about .partner__name {
  font-size: 15px;
  font-weight: 700;
  color: var(--paper);
  margin: 0 0 6px;
}

.page-about .partner p {
  font-size: 14px;
  line-height: 1.7;
  color: var(--slate);
  margin: 0;
  max-width: none !important;
}

/* ---------- 下一步 ---------- */
.page-about .about-sec--next {
  padding-bottom: 64px;
}

.page-about .next {
  display: grid;
  gap: 16px;
  margin-top: 8px;
}

.page-about .next__card {
  display: grid;
  gap: 8px;
  padding: 22px 20px;
  border: 1px solid var(--line-strong);
  border-radius: var(--radius-lg);
  background: linear-gradient(160deg, rgba(11, 42, 68, 0.9), rgba(6, 26, 43, 0.9));
  text-decoration: none;
  border-bottom-width: 1px;
  transition: transform 220ms var(--ease), border-color 220ms var(--ease);
}

.page-about .next__card:hover,
.page-about .next__card:focus-visible {
  transform: translateY(-4px);
  border-color: var(--cyan);
}

.page-about .next__card--coral:hover,
.page-about .next__card--coral:focus-visible {
  border-color: var(--coral);
}

.page-about .next__kicker {
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.14em;
  color: var(--slate);
}

.page-about .next__title {
  font-family: var(--font-display);
  font-size: 22px;
  font-weight: 900;
  letter-spacing: -0.01em;
  color: var(--mist);
}

.page-about .next__text {
  font-size: 14px;
  line-height: 1.75;
  color: var(--slate);
}

.page-about .next__go {
  margin-top: 6px;
  font-size: 14px;
  font-weight: 700;
  color: var(--cyan);
}

.page-about .next__card--coral .next__go {
  color: var(--coral);
}

/* ---------- 响应式 ---------- */
@media (min-width: 720px) {
  .page-about .about-hero {
    padding: 26px 0 60px;
  }

  .page-about .about-hero__art {
    right: -22%;
    width: 118%;
    opacity: 0.38;
  }

  .page-about .about-hero .lede {
    font-size: 17px;
  }

  .page-about .about-sec {
    padding: 60px 0;
  }

  .page-about .svc {
    grid-template-columns: 48px 1fr auto;
    gap: 8px 18px;
    align-items: start;
  }

  .page-about .svc .chip {
    grid-column: 3;
    justify-self: end;
    white-space: nowrap;
  }

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

  .page-about .team__item {
    padding: 20px 18px 18px 0;
  }

  .page-about .team__item:nth-child(even) {
    padding-left: 18px;
    border-left: 1px solid var(--about-line);
  }

  .page-about .cov {
    grid-template-columns: minmax(0, 1.15fr) minmax(0, 0.85fr);
    align-items: start;
    gap: 28px;
  }

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

  .page-about .q {
    grid-template-columns: 104px 1fr;
    align-items: baseline;
  }

  .page-about .partners {
    grid-template-columns: repeat(3, minmax(0, 1fr));
    gap: 24px;
  }

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

@media (min-width: 1000px) {
  .page-about .about-hero {
    padding: 32px 0 76px;
  }

  .page-about .about-hero__grid {
    margin-top: 30px;
    row-gap: 0;
  }

  .page-about .about-hero__rail {
    padding-left: 22px;
    margin-top: 6px;
  }

  .page-about .about-sec {
    padding: 76px 0;
  }

  .page-about .about-sec__row {
    row-gap: 0;
    column-gap: 48px;
  }

  .page-about .about-sec__rail {
    position: sticky;
    top: 96px;
    align-self: start;
    padding-top: 8px;
  }

  .page-about .rail-note {
    writing-mode: vertical-rl;
    letter-spacing: 0.34em;
    line-height: 1.6;
  }

  .page-about .about-sec__body p {
    font-size: 17px;
  }

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

  .page-about .team__item,
  .page-about .team__item:nth-child(even) {
    padding: 0 18px 0 0;
    border-left: 0;
    border-top: 1px solid var(--about-line);
    border-bottom: 0;
  }

  .page-about .team__item:nth-child(2) {
    margin-top: 26px;
  }

  .page-about .team__item:nth-child(3) {
    margin-top: 10px;
  }

  .page-about .team__item:nth-child(4) {
    margin-top: 36px;
  }

  .page-about .about-sec--next {
    padding-bottom: 96px;
  }

  .page-about .next__card {
    padding: 28px 26px;
  }
}

@media (prefers-reduced-motion: reduce) {
  .page-about .next__card,
  .page-about .stat__hint,
  .page-about .tl__mark {
    transition: none;
  }

  .page-about .next__card:hover,
  .page-about .next__card:focus-visible {
    transform: none;
  }
}