.page-about {
  --about-rail: 240px;
  --about-gap: clamp(20px, 4vw, 40px);
  display: block;
  overflow-x: hidden;
}

.page-about .breadcrumb {
  padding-top: 14px;
}

.page-about .eyebrow {
  margin: 0;
  font-family: var(--font-label);
  font-size: 12px;
  letter-spacing: .16em;
  text-transform: uppercase;
  color: var(--mint);
}

.page-about .about-h2 {
  margin: 0 0 18px;
  font-family: var(--font-sans);
  font-weight: 900;
  font-size: clamp(26px, 3.6vw, 40px);
  line-height: 1.2;
  letter-spacing: -.005em;
  color: var(--chalk);
}

/* ---------- 首屏 ---------- */
.page-about .about-hero {
  position: relative;
  isolation: isolate;
  padding: clamp(20px, 3vw, 36px) 0 clamp(36px, 6vw, 84px);
  overflow: hidden;
}

.page-about .about-hero::before {
  content: "";
  position: absolute;
  inset: -20% -6% 0;
  z-index: -1;
  background-image:
    linear-gradient(rgba(139, 92, 246, .10) 1px, transparent 1px),
    linear-gradient(90deg, rgba(139, 92, 246, .10) 1px, transparent 1px);
  background-size: 72px 72px;
  -webkit-mask-image: radial-gradient(120% 88% at 78% 0%, #000 0%, transparent 72%);
  mask-image: radial-gradient(120% 88% at 78% 0%, #000 0%, transparent 72%);
  pointer-events: none;
}

.page-about .hero-grid {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: var(--about-gap);
}

.page-about .about-hero h1 {
  margin: 14px 0 0;
  font-family: var(--font-sans);
  font-weight: 900;
  font-size: clamp(32px, 6.4vw, 68px);
  line-height: 1.08;
  letter-spacing: -.01em;
  color: var(--chalk);
}

.page-about .about-hero h1 .accent {
  display: block;
  margin-top: 6px;
  background: linear-gradient(96deg, var(--purple) 6%, var(--mint) 92%);
  -webkit-background-clip: text;
  background-clip: text;
  color: transparent;
}

.page-about .hero-lede {
  max-width: 56ch;
  margin: 20px 0 0;
  font-size: 16px;
  line-height: 1.78;
  color: rgba(243, 245, 255, .78);
}

.page-about .hero-facts {
  list-style: none;
  margin: clamp(24px, 4vw, 38px) 0 0;
  padding: 0;
  display: flex;
  flex-wrap: wrap;
  gap: clamp(16px, 3vw, 36px);
}

.page-about .hero-facts li {
  display: flex;
  flex-direction: column;
  gap: 4px;
  padding-left: 12px;
  border-left: 2px solid var(--line-purple);
}

.page-about .hf-num {
  font-family: var(--font-mono);
  font-size: clamp(22px, 3vw, 30px);
  line-height: 1.1;
  color: var(--mint);
}

.page-about .hf-label {
  font-size: 12px;
  letter-spacing: .06em;
  color: var(--steel);
}

.page-about .hero-rail {
  position: relative;
  padding: 22px 20px 20px;
  background: linear-gradient(158deg, rgba(59, 29, 110, .58), rgba(17, 21, 38, .94));
  border: 1px solid var(--line-purple);
  clip-path: polygon(0 0, 100% 0, 100% calc(100% - 18px), calc(100% - 18px) 100%, 0 100%);
}

.page-about .hero-rail::before {
  content: "";
  position: absolute;
  top: 0;
  left: 0;
  width: 64px;
  height: 2px;
  background: linear-gradient(90deg, var(--purple), var(--mint));
}

.page-about .rail-kicker {
  margin: 0 0 10px;
  font-family: var(--font-label);
  font-size: 11px;
  letter-spacing: .18em;
  text-transform: uppercase;
  color: var(--mint);
}

.page-about .rail-text {
  margin: 0;
  font-size: 14px;
  line-height: 1.75;
  color: rgba(243, 245, 255, .74);
}

.page-about .rail-sig {
  margin: 14px 0 0;
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: .06em;
  color: var(--steel);
}

/* ---------- 通用双栏 ---------- */
.page-about .about-section {
  position: relative;
  padding: clamp(40px, 6.5vw, 88px) 0;
}

.page-about .about-section + .about-section {
  border-top: 1px solid var(--line);
}

.page-about .split {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: var(--about-gap);
}

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

.page-about .rail-year {
  align-self: flex-start;
  display: inline-block;
  margin: 0;
  padding: 6px 18px 6px 12px;
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: .14em;
  color: var(--mint);
  background: rgba(46, 242, 176, .10);
  border-left: 2px solid var(--mint);
  clip-path: polygon(0 0, 100% 0, calc(100% - 12px) 100%, 0 100%);
}

.page-about .rail-note {
  margin: 0;
  padding-left: 12px;
  font-size: 13px;
  line-height: 1.8;
  color: var(--steel);
}

.page-about .body-col {
  min-width: 0;
}

.page-about .body-col p {
  margin: 0 0 18px;
  font-size: 16px;
  line-height: 1.8;
  color: rgba(243, 245, 255, .78);
}

.page-about .body-col p:last-child {
  margin-bottom: 0;
}

/* ---------- 故事与图片 ---------- */
.page-about .story-figure {
  margin: clamp(24px, 4vw, 36px) 0;
}

.page-about .story-figure img,
.page-about .team-figure img {
  display: block;
  width: 100%;
  height: auto;
  max-width: 100%;
  object-fit: cover;
  border: 1px solid var(--line);
  background: var(--panel);
}

.page-about .fig-caption {
  margin-top: 10px;
  padding-left: 10px;
  font-size: 13px;
  line-height: 1.7;
  color: var(--steel);
  border-left: 2px solid var(--line-purple);
}

/* ---------- 使命 ---------- */
.page-about .about-mission {
  position: relative;
  isolation: isolate;
  overflow: hidden;
  padding: clamp(40px, 6.5vw, 88px) 0;
  background:
    radial-gradient(120% 120% at 100% 0%, rgba(59, 29, 110, .8), transparent 62%),
    var(--panel-deep);
  border-top: 1px solid var(--line-purple);
  border-bottom: 1px solid var(--line-purple);
}

.page-about .about-mission::before {
  content: "";
  position: absolute;
  inset: 0;
  z-index: -1;
  background-image: repeating-linear-gradient(
    -45deg,
    rgba(139, 92, 246, .07) 0 1px,
    transparent 1px 22px
  );
  pointer-events: none;
}

.page-about .mission-head {
  max-width: 760px;
  margin-bottom: clamp(24px, 4vw, 40px);
}

.page-about .mission-grid {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: clamp(22px, 4vw, 44px);
  align-items: start;
}

.page-about .mission-figure {
  margin: 0;
}

.page-about .mission-figure img {
  display: block;
  width: 100%;
  height: auto;
  max-width: 100%;
  object-fit: cover;
  background: var(--panel);
  clip-path: polygon(0 0, 100% 0, 100% 88%, 88% 100%, 0 100%);
}

.page-about .mission-text p {
  margin: 0 0 16px;
  font-size: 16px;
  line-height: 1.8;
  color: rgba(243, 245, 255, .8);
}

.page-about .mission-points {
  list-style: none;
  margin: 22px 0 0;
  padding: 0;
  display: grid;
  gap: 12px;
}

.page-about .mission-points li {
  position: relative;
  padding-left: 22px;
  font-size: 14px;
  line-height: 1.75;
  color: rgba(243, 245, 255, .84);
}

.page-about .mission-points li::before {
  content: "";
  position: absolute;
  left: 0;
  top: .62em;
  width: 9px;
  height: 9px;
  background: var(--mint);
  transform: rotate(45deg);
}

/* ---------- 四类使用者 ---------- */
.page-about .scene-list {
  list-style: none;
  margin: 0;
  padding: 0;
}

.page-about .scene-row {
  display: grid;
  grid-template-columns: 46px minmax(0, 1fr);
  gap: clamp(12px, 2.5vw, 26px);
  padding: clamp(18px, 3vw, 26px) 0;
  border-top: 1px solid var(--line);
  transition: border-color .25s var(--ease);
}

.page-about .scene-row:last-child {
  border-bottom: 1px solid var(--line);
}

.page-about .scene-row:hover {
  border-top-color: var(--mint);
}

.page-about .scene-index {
  font-family: var(--font-mono);
  font-size: clamp(20px, 2.6vw, 26px);
  line-height: 1.2;
  color: rgba(139, 92, 246, .9);
  transition: color .25s var(--ease);
}

.page-about .scene-row:hover .scene-index {
  color: var(--mint);
}

.page-about .scene-body h3 {
  margin: 0 0 8px;
  font-size: clamp(17px, 2vw, 20px);
  font-weight: 700;
  color: var(--chalk);
}

.page-about .scene-body p {
  margin: 0;
  font-size: 15px;
  line-height: 1.78;
  color: rgba(243, 245, 255, .74);
}

/* ---------- 资料流程 ---------- */
.page-about .flow-head {
  max-width: 720px;
}

.page-about .flow-head .section-note {
  margin: 0;
  font-size: 15px;
  line-height: 1.8;
  color: var(--steel);
}

.page-about .flow-steps {
  list-style: none;
  margin: clamp(24px, 4vw, 40px) 0 0;
  padding: 1px;
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 1px;
  background: var(--line);
  border: 1px solid var(--line);
}

.page-about .flow-step {
  position: relative;
  padding: 22px 20px 26px;
  background: var(--panel);
  transition: background .25s var(--ease);
}

.page-about .flow-step:hover {
  background: #151A2E;
}

.page-about .flow-num {
  display: block;
  margin-bottom: 10px;
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: .14em;
  color: var(--mint);
}

.page-about .flow-step h3 {
  margin: 0 0 8px;
  font-size: 17px;
  font-weight: 700;
  color: var(--chalk);
}

.page-about .flow-step p {
  margin: 0;
  font-size: 14px;
  line-height: 1.75;
  color: rgba(243, 245, 255, .7);
}

/* ---------- 时间线 ---------- */
.page-about .timeline {
  list-style: none;
  margin: 0;
  padding: 4px 0 0 22px;
  border-left: 1px solid var(--line-mid);
}

.page-about .tl-item {
  position: relative;
  padding-bottom: 14px;
}

.page-about .tl-item::before {
  content: "";
  position: absolute;
  left: -27px;
  top: 13px;
  width: 9px;
  height: 9px;
  background: var(--purple);
  transform: rotate(45deg);
  transition: background .25s var(--ease);
}

.page-about .tl-item:hover::before {
  background: var(--mint);
}

.page-about .tl-details summary {
  display: flex;
  align-items: baseline;
  gap: 12px;
  padding: 6px 0;
  cursor: pointer;
  list-style: none;
  font-size: clamp(17px, 2.2vw, 21px);
  font-weight: 700;
  color: var(--chalk);
  transition: color .25s var(--ease);
}

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

.page-about .tl-details summary:hover,
.page-about .tl-details[open] summary {
  color: var(--mint);
}

.page-about .tl-details summary::after {
  content: "+";
  margin-left: auto;
  font-family: var(--font-mono);
  font-size: 15px;
  font-weight: 400;
  color: var(--purple);
}

.page-about .tl-details[open] summary::after {
  content: "−";
  color: var(--mint);
}

.page-about .tl-year {
  font-family: var(--font-mono);
  font-size: 13px;
  letter-spacing: .1em;
  color: var(--purple);
}

.page-about .tl-details[open] .tl-year {
  color: var(--mint);
}

.page-about .tl-details p {
  margin: 4px 0 14px;
  padding: 14px 16px;
  font-size: 14px;
  line-height: 1.8;
  color: rgba(243, 245, 255, .76);
  background: var(--panel);
  border-left: 2px solid var(--line-purple);
}

/* ---------- 团队 ---------- */
.page-about .team-bar {
  display: flex;
  height: 10px;
  margin: 22px 0 26px;
  gap: 3px;
}

.page-about .team-bar .tb {
  display: block;
  height: 100%;
}

.page-about .tb-edit {
  flex: 16 1 0;
  background: var(--purple);
}

.page-about .tb-tech {
  flex: 9 1 0;
  background: var(--mint);
}

.page-about .tb-cs {
  flex: 3 1 0;
  background: var(--ice);
}

.page-about .crew-list {
  list-style: none;
  margin: 0;
  padding: 0;
  display: grid;
  gap: 1px;
  background: var(--line);
  border: 1px solid var(--line);
}

.page-about .crew-item {
  display: grid;
  grid-template-columns: 54px minmax(0, 1fr);
  gap: 14px;
  align-items: start;
  padding: 18px 18px 20px;
  background: var(--panel);
}

.page-about .crew-num {
  font-family: var(--font-mono);
  font-size: 24px;
  line-height: 1.2;
  color: var(--mint);
}

.page-about .crew-text h3 {
  margin: 0 0 6px;
  font-size: 16px;
  font-weight: 700;
  color: var(--chalk);
}

.page-about .crew-text p {
  margin: 0;
  font-size: 14px;
  line-height: 1.75;
  color: rgba(243, 245, 255, .7);
}

.page-about .team-figure {
  margin: clamp(24px, 4vw, 34px) 0;
}

.page-about .network {
  margin-top: clamp(26px, 4vw, 38px);
  padding-top: clamp(20px, 3vw, 28px);
  border-top: 1px solid var(--line-purple);
}

.page-about .network-title {
  margin: 0 0 10px;
  font-size: clamp(18px, 2.2vw, 22px);
  font-weight: 700;
  color: var(--chalk);
}

.page-about .network p {
  margin: 0 0 20px;
  font-size: 15px;
  line-height: 1.8;
  color: rgba(243, 245, 255, .76);
}

.page-about .network-grid {
  list-style: none;
  margin: 0;
  padding: 0;
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 12px;
}

.page-about .network-grid li {
  display: flex;
  flex-direction: column;
  gap: 4px;
  padding: 16px 18px;
  background: rgba(17, 21, 38, .8);
  border-left: 2px solid var(--purple);
}

.page-about .net-num {
  font-family: var(--font-mono);
  font-size: 26px;
  line-height: 1.1;
  color: var(--chalk);
}

.page-about .net-label {
  font-size: 14px;
  font-weight: 700;
  color: var(--mint);
}

.page-about .net-desc {
  font-size: 12px;
  letter-spacing: .04em;
  color: var(--steel);
}

/* ---------- 服务准则 ---------- */
.page-about .about-principles {
  background: linear-gradient(180deg, rgba(17, 21, 38, .7), transparent 70%);
  border-top: 1px solid var(--line);
}

.page-about .principles-head {
  max-width: 720px;
  margin-bottom: clamp(22px, 3.5vw, 34px);
}

.page-about .principles-head .section-note {
  margin: 0;
  font-size: 15px;
  line-height: 1.8;
  color: var(--steel);
}

.page-about .principle-list {
  list-style: none;
  margin: 0;
  padding: 0;
  display: grid;
  gap: clamp(16px, 2.6vw, 24px);
}

.page-about .principle {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 10px;
  padding: 20px 22px;
  background: var(--panel);
  border-left: 3px solid var(--purple);
  transition: border-color .25s var(--ease), transform .25s var(--ease);
}

.page-about .principle:hover {
  border-left-color: var(--mint);
  transform: translateY(-2px);
}

.page-about .p-tag {
  align-self: start;
  justify-self: start;
  padding: 3px 10px;
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: .14em;
  color: var(--amber);
  background: rgba(255, 200, 87, .1);
  border: 1px solid rgba(255, 200, 87, .3);
}

.page-about .p-body h3 {
  margin: 0 0 8px;
  font-size: clamp(16px, 1.9vw, 19px);
  font-weight: 700;
  color: var(--chalk);
}

.page-about .p-body p {
  margin: 0;
  font-size: 14px;
  line-height: 1.8;
  color: rgba(243, 245, 255, .74);
}

/* ---------- 延伸入口 ---------- */
.page-about .about-next {
  padding: clamp(36px, 6vw, 76px) 0 clamp(44px, 7vw, 92px);
  border-top: 1px solid var(--line-purple);
}

.page-about .next-grid {
  list-style: none;
  margin: 0;
  padding: 0;
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 12px;
}

.page-about .next-card {
  display: flex;
  flex-direction: column;
  gap: 8px;
  padding: 20px 20px 18px;
  text-decoration: none;
  background: var(--panel);
  border: 1px solid var(--line);
  clip-path: polygon(0 0, 100% 0, 100% calc(100% - 14px), calc(100% - 14px) 100%, 0 100%);
  transition: border-color .25s var(--ease), transform .25s var(--ease), background .25s var(--ease);
}

.page-about .next-card:hover,
.page-about .next-card:focus-visible {
  transform: translateY(-2px);
  border-color: var(--mint);
  background: #151A2E;
}

.page-about .next-kicker {
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: .12em;
  color: var(--purple);
}

.page-about .next-title-text {
  font-size: 15px;
  font-weight: 700;
  line-height: 1.55;
  color: var(--chalk);
}

.page-about .next-more {
  margin-top: 2px;
  font-size: 13px;
  color: var(--mint);
}

/* ---------- 断点 ---------- */
@media (min-width: 620px) {
  .page-about .network-grid {
    grid-template-columns: repeat(3, minmax(0, 1fr));
  }

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

  .page-about .principle {
    grid-template-columns: 76px minmax(0, 1fr);
    align-items: start;
    gap: 16px;
  }
}

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

@media (min-width: 900px) {
  .page-about .hero-grid {
    grid-template-columns: minmax(0, 1fr) minmax(0, 320px);
    align-items: end;
    gap: clamp(32px, 5vw, 72px);
  }

  .page-about .mission-grid {
    grid-template-columns: minmax(0, 1.05fr) minmax(0, 1fr);
    gap: clamp(28px, 4vw, 52px);
  }

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

@media (min-width: 940px) {
  .page-about .split {
    grid-template-columns: minmax(0, var(--about-rail)) minmax(0, 1fr);
    gap: clamp(36px, 6vw, 84px);
  }

  .page-about .rail-col.is-sticky {
    position: sticky;
    top: calc(var(--header-h) + 28px);
    align-self: start;
  }

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

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

@media (prefers-reduced-motion: reduce) {
  .page-about .scene-row,
  .page-about .scene-index,
  .page-about .flow-step,
  .page-about .principle,
  .page-about .next-card,
  .page-about .tl-item::before {
    transition: none;
  }

  .page-about .principle:hover,
  .page-about .next-card:hover,
  .page-about .next-card:focus-visible {
    transform: none;
  }
}