.page-about {
  display: block;
  color: var(--text);
  overflow-x: hidden;
}

/* ---------- 首屏 ---------- */
.page-about .about-hero {
  position: relative;
  overflow: hidden;
  padding: clamp(24px, 4vw, 40px) 0 clamp(40px, 6vw, 76px);
  background:
    radial-gradient(120% 90% at 84% 0%, rgba(255, 106, 26, 0.14), transparent 58%),
    linear-gradient(180deg, var(--indigo-2), var(--indigo) 78%);
}

.page-about .about-hero::before {
  content: "";
  position: absolute;
  inset: 0;
  pointer-events: none;
  opacity: 0.7;
  background-image: repeating-linear-gradient(
    0deg,
    rgba(140, 147, 180, 0.09) 0 1px,
    transparent 1px 44px
  );
}

.page-about .about-hero::after {
  content: "";
  position: absolute;
  left: 0;
  right: 0;
  bottom: 0;
  height: 1px;
  background: linear-gradient(90deg, transparent, var(--orange), var(--signal), transparent);
  opacity: 0.55;
}

.page-about .about-hero__grid {
  position: relative;
  z-index: 1;
  display: grid;
  gap: clamp(26px, 4vw, 48px);
  align-items: end;
}

.page-about .about-hero__copy .crumb {
  margin-bottom: clamp(18px, 3vw, 30px);
}

.page-about .about-hero h1 {
  margin: 14px 0 18px;
  max-width: 13ch;
  font-family: var(--sans);
  font-weight: 900;
  font-size: clamp(32px, 6vw, 56px);
  line-height: 1.1;
  letter-spacing: -0.01em;
  color: var(--paper);
}

.page-about .about-hero__lede {
  max-width: 36em;
  margin: 0;
  font-size: clamp(15px, 1.5vw, 17px);
  line-height: 1.85;
  color: var(--text);
}

.page-about .about-hero__frame {
  border: 1px solid var(--edge);
  box-shadow: 10px 10px 0 rgba(10, 12, 26, 0.55);
}

/* 首屏数据带 */
.page-about .about-metrics {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(140px, 1fr));
  gap: 1px;
  margin: clamp(26px, 4vw, 40px) 0 0;
  padding: 0;
  border: 1px solid var(--edge);
  background: var(--edge);
}

.page-about .about-metrics__cell {
  background: var(--indigo-2);
  padding: 14px 14px 16px;
}

.page-about .about-metrics dt {
  margin: 0 0 6px;
  font-family: var(--mono);
  font-size: 12px;
  letter-spacing: 0.08em;
  color: var(--mute);
}

.page-about .about-metrics dd {
  margin: 0;
  font-family: var(--mono);
  font-variant-numeric: tabular-nums;
  font-size: 19px;
  color: var(--paper);
}

.page-about .about-metrics dd .num {
  color: var(--orange);
}

/* ---------- 页面骨架 ---------- */
.page-about .about-shell {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: clamp(28px, 5vw, 56px);
  padding-top: clamp(40px, 7vw, 84px);
  padding-bottom: clamp(48px, 8vw, 96px);
}

.page-about .about-nav {
  align-self: start;
}

.page-about .about-nav__title {
  margin: 0 0 14px;
  font-family: var(--mono);
  font-size: 11.5px;
  letter-spacing: 0.2em;
  color: var(--mute);
}

.page-about .about-nav__list {
  display: flex;
  flex-wrap: wrap;
  gap: 4px 18px;
  margin: 0;
  padding: 0;
  list-style: none;
}

.page-about .about-nav__list a {
  display: block;
  padding: 6px 0;
  border-bottom: 1px solid var(--edge);
  color: var(--mute);
  font-size: 13.5px;
  line-height: 1.5;
  text-decoration: none;
  transition: color 120ms linear, border-color 120ms linear;
}

.page-about .about-nav__list a:hover,
.page-about .about-nav__list a:focus-visible {
  color: var(--orange-2);
  border-bottom-color: var(--orange);
}

.page-about .about-main {
  min-width: 0;
}

/* ---------- 通用章节 ---------- */
.page-about .about-block {
  padding-bottom: clamp(46px, 8vw, 96px);
}

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

.page-about .sec-head {
  display: flex;
  flex-wrap: wrap;
  align-items: flex-start;
  gap: 10px 20px;
  margin-bottom: clamp(20px, 3vw, 32px);
}

.page-about .sec-head h2 {
  flex: 1 1 auto;
  margin: 0;
  font-family: var(--sans);
  font-weight: 900;
  font-size: clamp(23px, 3.6vw, 36px);
  line-height: 1.2;
  letter-spacing: -0.01em;
  color: var(--paper);
}

.page-about .sec-head__side {
  display: none;
  writing-mode: vertical-rl;
  font-family: var(--mono);
  font-size: 11.5px;
  letter-spacing: 0.24em;
  color: var(--mute);
}

.page-about .about-lede {
  max-width: 38em;
  margin: 0 0 16px;
  font-size: 16px;
  line-height: 1.85;
  color: var(--text);
}

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

.page-about .about-lede a {
  color: var(--orange-2);
  text-decoration: underline;
  text-underline-offset: 3px;
}

.page-about .about-lede a:hover {
  color: var(--orange);
}

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

.page-about .axis::before {
  content: "";
  position: absolute;
  left: 7px;
  top: 8px;
  bottom: 8px;
  width: 2px;
  background: linear-gradient(180deg, var(--orange), var(--signal) 52%, var(--edge));
}

.page-about .axis__item {
  position: relative;
  padding-bottom: clamp(52px, 9vw, 112px);
}

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

.page-about .axis__dot {
  position: absolute;
  left: -30px;
  top: 14px;
  width: 16px;
  height: 16px;
  border-radius: 50%;
  background: var(--orange);
  box-shadow: 0 0 0 4px var(--indigo);
}

.page-about .axis__card {
  padding: clamp(18px, 3vw, 28px);
  transition: transform 160ms ease-out, box-shadow 160ms ease-out;
}

.page-about .axis__card:hover {
  transform: translateY(-2px);
  box-shadow: 12px 14px 0 rgba(10, 12, 26, 0.6);
}

.page-about .axis__head {
  display: flex;
  flex-wrap: wrap;
  align-items: baseline;
  gap: 8px 16px;
  margin-bottom: 14px;
}

.page-about .axis__ord {
  padding-bottom: 2px;
  border-bottom: 2px solid var(--orange);
  font-family: var(--mono);
  font-size: 12px;
  letter-spacing: 0.16em;
  color: var(--ink);
}

.page-about .axis__head h3 {
  flex: 1 1 12em;
  margin: 0;
  font-family: var(--sans);
  font-weight: 900;
  font-size: clamp(18px, 2.4vw, 23px);
  line-height: 1.35;
  color: var(--ink);
}

.page-about .axis__card p {
  margin: 0 0 12px;
  font-size: 15px;
  line-height: 1.85;
  color: #33385A;
}

.page-about .axis__card p:last-of-type {
  margin-bottom: 0;
}

.page-about .axis__stats {
  display: flex;
  flex-wrap: wrap;
  gap: 14px 30px;
  margin: 18px 0 0;
  padding-top: 14px;
  border-top: 1px dashed #C6C2B4;
}

.page-about .axis__stats dt {
  margin: 0 0 4px;
  font-family: var(--mono);
  font-size: 11.5px;
  letter-spacing: 0.1em;
  color: #6B6F87;
}

.page-about .axis__stats dd {
  margin: 0;
  font-family: var(--mono);
  font-variant-numeric: tabular-nums;
  font-size: 16px;
  color: var(--ink);
}

/* ---------- 编辑流程 ---------- */
.page-about .flow {
  display: grid;
  gap: clamp(24px, 4vw, 40px);
}

.page-about .flow__frame {
  border: 1px solid var(--edge);
  box-shadow: 8px 8px 0 rgba(10, 12, 26, 0.5);
}

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

.page-about .flow__step {
  position: relative;
  padding: 18px 0 18px 54px;
  border-top: 1px solid var(--edge);
}

.page-about .flow__step:last-child {
  border-bottom: 1px solid var(--edge);
}

.page-about .flow__idx {
  position: absolute;
  left: 0;
  top: 18px;
  font-size: 20px;
  color: var(--orange);
}

.page-about .flow__step h3 {
  margin: 0 0 8px;
  font-family: var(--sans);
  font-weight: 800;
  font-size: clamp(16px, 2vw, 19px);
  line-height: 1.4;
  color: var(--paper);
}

.page-about .flow__step p {
  margin: 0;
  font-size: 15px;
  line-height: 1.85;
  color: var(--text);
}

.page-about .flow__step a {
  color: var(--orange-2);
  text-decoration: underline;
  text-underline-offset: 3px;
}

/* ---------- 团队 ---------- */
.page-about .crew {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(160px, 1fr));
  gap: 1px;
  margin-bottom: clamp(20px, 3vw, 32px);
  border: 1px solid var(--edge);
  background: var(--edge);
}

.page-about .crew__cell {
  padding: 20px 18px 22px;
  background: var(--indigo-2);
}

.page-about .crew__num {
  margin: 0 0 10px;
  font-family: var(--mono);
  font-variant-numeric: tabular-nums;
  font-size: clamp(24px, 3.4vw, 34px);
  line-height: 1.1;
  color: var(--orange);
}

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

.page-about .crew__note {
  margin: 0;
  font-size: 12.5px;
  line-height: 1.7;
  color: var(--mute);
}

/* ---------- 合作与校验 ---------- */
.page-about .partners__frame {
  margin-bottom: clamp(20px, 3vw, 30px);
  border: 1px solid var(--edge);
}

/* ---------- 边界列表 ---------- */
.page-about .notdo {
  margin: 0;
  padding: 0;
  list-style: none;
  border-top: 1px solid var(--edge);
}

.page-about .notdo__item {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 10px;
  padding: 18px 0;
  border-bottom: 1px solid var(--edge);
}

.page-about .notdo__item p {
  margin: 0;
  font-size: 15px;
  line-height: 1.85;
  color: var(--text);
}

.page-about .notdo__item .tag {
  justify-self: start;
}

/* ---------- 页尾引导 ---------- */
.page-about .about-cta {
  border-top: 1px solid var(--edge);
  background:
    radial-gradient(90% 140% at 6% 100%, rgba(43, 217, 138, 0.12), transparent 62%),
    var(--indigo-2);
  padding: clamp(36px, 6vw, 68px) 0;
}

.page-about .about-cta__inner {
  display: grid;
  gap: 22px;
}

.page-about .about-cta h2 {
  margin: 0 0 10px;
  font-family: var(--sans);
  font-weight: 900;
  font-size: clamp(22px, 3vw, 30px);
  line-height: 1.25;
  color: var(--paper);
}

.page-about .about-cta p {
  margin: 0;
  max-width: 34em;
  font-size: 15px;
  line-height: 1.85;
  color: var(--text);
}

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

/* ---------- 响应式 ---------- */
@media (min-width: 640px) {
  .page-about .notdo__item {
    grid-template-columns: 88px minmax(0, 1fr);
    align-items: start;
    gap: 16px;
  }

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

  .page-about .about-cta__actions {
    justify-content: flex-end;
  }
}

@media (min-width: 900px) {
  .page-about .flow {
    grid-template-columns: minmax(0, 0.82fr) minmax(0, 1.18fr);
    align-items: start;
  }

  .page-about .sec-head__side {
    display: block;
  }
}

@media (min-width: 960px) {
  .page-about .about-hero__grid {
    grid-template-columns: minmax(0, 1.06fr) minmax(0, 0.94fr);
  }

  .page-about .about-hero__frame {
    margin-top: 28px;
  }

  .page-about .about-shell {
    grid-template-columns: minmax(180px, 220px) minmax(0, 1fr);
    align-items: start;
  }

  .page-about .about-nav {
    position: sticky;
    top: calc(var(--masthead-h) + 24px);
  }

  .page-about .about-nav__list {
    display: block;
    gap: 0;
  }

  .page-about .about-nav__list a {
    padding: 9px 0 9px 12px;
    border-bottom: 0;
    border-left: 2px solid var(--edge);
  }

  .page-about .about-nav__list a:hover,
  .page-about .about-nav__list a:focus-visible {
    border-left-color: var(--orange);
  }
}

@media (prefers-reduced-motion: reduce) {
  .page-about .axis__card,
  .page-about .about-nav__list a {
    transition: none;
  }

  .page-about .axis__card:hover {
    transform: none;
  }
}