.page-about {
  --about-rail: 172px;
  --about-col-gap: 48px;
  background: var(--night);
  color: var(--paper-86);
  overflow-x: clip;
}

/* ---------- 首屏 ---------- */
.page-about .about-hero {
  position: relative;
  overflow: hidden;
  padding: 34px 0 44px;
  border-bottom: 1px solid var(--line-soft);
  background:
    radial-gradient(120% 110% at 6% -20%, rgba(34, 224, 214, .18), transparent 56%),
    radial-gradient(90% 90% at 102% 118%, rgba(242, 180, 65, .1), transparent 58%),
    linear-gradient(180deg, var(--night) 0%, var(--deep) 100%);
}

.page-about .about-hero__label {
  margin-top: 22px;
  color: var(--cyan);
}

.page-about .about-hero h1 {
  margin: 14px 0 0;
  max-width: 15em;
  font-size: var(--step-5);
  font-weight: 900;
  line-height: 1.14;
  letter-spacing: -.02em;
  color: var(--paper);
}

.page-about .about-hero__lede {
  margin: 18px 0 0;
  max-width: 34em;
  font-size: var(--step-1);
  line-height: 1.75;
  color: var(--paper-70);
}

.page-about .about-hero__facts {
  list-style: none;
  display: flex;
  flex-wrap: wrap;
  gap: 10px 24px;
  margin: 26px 0 0;
  padding: 18px 0 0;
  border-top: 1px solid var(--line-soft);
}

.page-about .about-hero__facts li {
  display: flex;
  align-items: baseline;
  gap: 7px;
  font-size: 13px;
  color: var(--paper-52);
}

.page-about .about-hero__facts .mono {
  font-size: 15px;
  font-weight: 700;
  color: var(--gold);
}

@media (min-width: 900px) {
  .page-about .about-hero {
    padding: 44px 0 56px;
  }
  .page-about .about-hero::after {
    content: "";
    position: absolute;
    right: -6%;
    top: 0;
    bottom: 0;
    width: 36%;
    pointer-events: none;
    background:
      linear-gradient(105deg, transparent 0 40%, rgba(34, 224, 214, .16) 40% 40.3%, transparent 40.3%),
      linear-gradient(105deg, transparent 0 58%, rgba(255, 77, 126, .14) 58% 58.3%, transparent 58.3%);
  }
}

/* ---------- 主栅格 ---------- */
.page-about .about-grid {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 28px;
  padding-top: 40px;
  padding-bottom: 72px;
}

@media (min-width: 1024px) {
  .page-about .about-grid {
    grid-template-columns: var(--about-rail) minmax(0, 1fr);
    column-gap: var(--about-col-gap);
    padding-top: 60px;
  }
}

/* ---------- 左侧章节栏 ---------- */
.page-about .about-rail {
  display: none;
}

@media (min-width: 1024px) {
  .page-about .about-rail {
    display: block;
    position: sticky;
    top: 120px;
    align-self: start;
    padding-left: 15px;
    border-left: 1px solid var(--line-soft);
  }
}

.page-about .about-rail__title {
  margin: 0 0 14px;
  font-family: var(--mono);
  font-size: 11px;
  letter-spacing: .16em;
  color: var(--stone);
}

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

.page-about .about-rail__list a {
  display: flex;
  align-items: baseline;
  gap: 9px;
  font-size: 13px;
  color: var(--paper-52);
  text-decoration: none;
  transition: color .24s var(--ease), transform .24s var(--ease);
}

.page-about .about-rail__list a:hover,
.page-about .about-rail__list a:focus-visible {
  color: var(--cyan);
  transform: translateX(3px);
}

.page-about .about-rail__list .mono {
  font-size: 11px;
  letter-spacing: .08em;
  color: var(--cyan-line);
}

/* ---------- 右栏正文流 ---------- */
.page-about .about-body {
  min-width: 0;
  display: grid;
  gap: 60px;
}

@media (min-width: 768px) {
  .page-about .about-body {
    gap: 80px;
  }
}

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

.page-about .about-section[data-reveal].is-visible {
  animation: aboutRise .52s var(--ease) both;
}

@keyframes aboutRise {
  from { opacity: 0; transform: translateY(18px); }
}

.page-about .about-sec__head {
  display: flex;
  align-items: baseline;
  gap: 14px;
  margin-bottom: 20px;
  padding-bottom: 12px;
  border-bottom: 1px solid var(--line-soft);
}

.page-about .about-sec__num {
  flex: none;
  font-size: 12px;
  letter-spacing: .12em;
  color: var(--cyan-line);
  transition: color .3s var(--ease);
}

.page-about .about-section.is-active .about-sec__num {
  color: var(--cyan);
}

.page-about .about-sec__title {
  margin: 0;
  font-size: var(--step-3);
  font-weight: 800;
  line-height: 1.3;
  letter-spacing: -.015em;
  color: var(--paper);
}

.page-about .about-section .prose {
  max-width: 40em;
  margin: 0 0 16px;
  line-height: 1.78;
  color: var(--paper-70);
}

.page-about .about-section .prose:last-child {
  margin-bottom: 0;
}

.page-about .about-pull {
  margin: 24px 0;
  padding: 18px 20px 18px 22px;
  border-left: 3px solid var(--cyan);
  background: linear-gradient(90deg, rgba(34, 224, 214, .1), rgba(34, 224, 214, 0));
  font-size: var(--step-1);
  line-height: 1.7;
  color: var(--paper);
}

/* ---------- 图形容器 ---------- */
.page-about .about-figure {
  margin: 0 0 26px;
  overflow: hidden;
  border: 1px solid var(--line-soft);
  background: var(--deep);
}

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

.page-about .about-figure--slant {
  clip-path: polygon(0 0, 100% 0, 100% 92%, 0 100%);
}

.page-about .about-figure__cap {
  display: block;
  padding: 10px 14px 12px;
  font-family: var(--mono);
  font-size: 11px;
  letter-spacing: .06em;
  color: var(--paper-52);
  border-top: 1px solid var(--line-faint);
}

/* ---------- 时间轴 ---------- */
.page-about .about-timeline {
  position: relative;
  list-style: none;
  margin: 30px 0 0;
  padding: 0 0 0 26px;
}

.page-about .about-timeline::before {
  content: "";
  position: absolute;
  left: 5px;
  top: 8px;
  bottom: 12px;
  width: 1px;
  background: linear-gradient(180deg, var(--cyan), var(--cyan-line) 42%, rgba(15, 111, 107, .18));
}

.page-about .about-timeline__item {
  position: relative;
  padding-bottom: 28px;
}

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

.page-about .about-timeline__item::before {
  content: "";
  position: absolute;
  left: -25px;
  top: 8px;
  width: 9px;
  height: 9px;
  border-radius: 50%;
  background: var(--night);
  border: 2px solid var(--cyan);
  transition: background .24s var(--ease), box-shadow .24s var(--ease);
}

.page-about .about-timeline__item:hover::before,
.page-about .about-timeline__item:focus-within::before {
  background: var(--cyan);
  box-shadow: 0 0 0 5px rgba(34, 224, 214, .16);
}

.page-about .about-timeline__year {
  display: block;
  margin-bottom: 4px;
  font-size: 15px;
  font-weight: 700;
  letter-spacing: .08em;
  color: var(--gold);
}

.page-about .about-timeline__title {
  margin: 0 0 6px;
  font-size: var(--step-1);
  font-weight: 800;
  letter-spacing: -.01em;
  color: var(--paper);
}

.page-about .about-timeline__lead {
  margin: 0;
  max-width: 42em;
  line-height: 1.72;
  color: var(--paper-70);
}

.page-about .about-timeline__more {
  max-height: 0;
  margin: 0;
  overflow: hidden;
  opacity: 0;
  font-size: 15px;
  line-height: 1.72;
  color: var(--paper-52);
  transition: max-height .38s var(--ease), opacity .3s var(--ease), margin-top .3s var(--ease);
}

.page-about .about-timeline__item:hover .about-timeline__more,
.page-about .about-timeline__item:focus-within .about-timeline__more {
  max-height: 300px;
  margin-top: 8px;
  opacity: 1;
}

/* ---------- 团队分工 ---------- */
.page-about .about-split {
  display: grid;
  gap: 24px;
}

@media (min-width: 880px) {
  .page-about .about-split {
    grid-template-columns: minmax(0, 7fr) minmax(0, 5fr);
    column-gap: 36px;
    align-items: start;
  }
  .page-about .about-split .about-figure {
    margin-bottom: 0;
  }
}

.page-about .about-flow {
  list-style: none;
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
  margin: 22px 0 0;
  padding: 0;
}

.page-about .about-flow li {
  display: flex;
  align-items: center;
  gap: 8px;
  padding: 9px 15px;
  font-family: var(--mono);
  font-size: 13px;
  letter-spacing: .04em;
  color: var(--paper);
  background: var(--deep);
  border: 1px solid var(--line-soft);
  clip-path: polygon(0 0, calc(100% - 10px) 0, 100% 50%, calc(100% - 10px) 100%, 0 100%);
}

.page-about .about-flow li .mono {
  font-size: 11px;
  color: var(--cyan);
}

/* ---------- 统计数字 ---------- */
.page-about .about-stats {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 14px;
  margin: 28px 0 0;
}

@media (min-width: 760px) {
  .page-about .about-stats {
    grid-template-columns: repeat(4, minmax(0, 1fr));
  }
}

.page-about .about-stat {
  padding: 16px 16px 18px;
  background: var(--deep);
  border-bottom: 3px solid var(--paper);
  box-shadow: 0 16px 30px -24px rgba(5, 10, 20, .95);
}

.page-about .about-stat__value {
  display: block;
  font-family: var(--mono);
  font-variant-numeric: tabular-nums;
  font-size: clamp(26px, 4.4vw, 38px);
  font-weight: 700;
  line-height: 1.1;
  letter-spacing: -.02em;
  color: var(--gold);
}

.page-about .about-stat__label {
  display: block;
  margin-top: 9px;
  font-size: 13px;
  line-height: 1.55;
  color: var(--paper-52);
}

/* ---------- 合作生态 ---------- */
.page-about .about-pair {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 12px;
  margin-top: 6px;
}

@media (min-width: 760px) {
  .page-about .about-pair {
    grid-template-columns: repeat(3, minmax(0, 1fr));
  }
}

.page-about .about-pair__cell {
  padding: 16px 16px 18px;
  border-left: 2px solid var(--moss);
  background: rgba(16, 31, 58, .78);
}

.page-about .about-pair__cell:nth-child(2) {
  border-left-color: var(--clay);
}

.page-about .about-pair__cell:nth-child(3) {
  border-left-color: var(--gold);
}

.page-about .about-pair__num {
  display: block;
  font-size: clamp(24px, 3.6vw, 32px);
  font-weight: 700;
  line-height: 1.15;
  letter-spacing: -.02em;
  color: var(--paper);
}

.page-about .about-pair__label {
  display: block;
  margin-top: 8px;
  font-size: 13px;
  line-height: 1.6;
  color: var(--paper-52);
}

/* ---------- 使用场景 ---------- */
.page-about .about-scenes {
  list-style: none;
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 14px;
  margin: 26px 0 0;
  padding: 0;
}

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

.page-about .about-scene {
  position: relative;
  padding: 20px 18px 22px;
  background: linear-gradient(180deg, var(--deep), rgba(16, 31, 58, .72));
  border: 1px solid var(--line-faint);
}

.page-about .about-scene::after {
  content: "";
  position: absolute;
  left: 18px;
  right: 18px;
  bottom: 0;
  height: 2px;
  background: linear-gradient(90deg, var(--cyan), rgba(34, 224, 214, 0));
}

.page-about .about-scene__val {
  display: block;
  font-size: clamp(28px, 4.6vw, 40px);
  font-weight: 700;
  line-height: 1.1;
  letter-spacing: -.02em;
  color: var(--cyan);
}

.page-about .about-scene__title {
  margin: 12px 0 6px;
  font-size: var(--step-1);
  font-weight: 800;
  letter-spacing: -.01em;
  color: var(--paper);
}

.page-about .about-scene p {
  margin: 0;
  font-size: 15px;
  line-height: 1.7;
  color: var(--paper-70);
}

/* ---------- 下一步 ---------- */
.page-about .about-next {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 1px;
  background: var(--line-soft);
  border: 1px solid var(--line-soft);
}

@media (min-width: 780px) {
  .page-about .about-next {
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }
}

.page-about .about-next__col {
  padding: 24px 22px 28px;
  background: var(--deep);
}

.page-about .about-next__col:first-child {
  border-top: 3px solid var(--cyan);
}

.page-about .about-next__col:last-child {
  border-top: 3px solid var(--rose);
}

.page-about .about-next__title {
  margin: 10px 0 8px;
  font-size: var(--step-2);
  font-weight: 800;
  letter-spacing: -.01em;
  color: var(--paper);
}

.page-about .about-next__text {
  margin: 0 0 20px;
  font-size: 15px;
  line-height: 1.72;
  color: var(--paper-70);
}

@media (prefers-reduced-motion: reduce) {
  .page-about .about-section[data-reveal].is-visible {
    animation: none;
  }
  .page-about .about-rail__list a,
  .page-about .about-timeline__item::before,
  .page-about .about-timeline__more {
    transition: none;
  }
}