.page-about {
  --ab-pad: clamp(56px, 10vw, 124px);
  --ab-gutter: clamp(16px, 4vw, 40px);
  --ab-toc: 178px;
  background: var(--ink);
  color: var(--cold);
  font-family: var(--font-body);
  padding-bottom: clamp(48px, 8vw, 96px);
}

/* ---------- 首屏 ---------- */
.page-about .about-hero {
  max-width: var(--wrap);
  margin: 0 auto;
  padding: clamp(24px, 5vw, 48px) var(--ab-gutter) clamp(36px, 7vw, 76px);
  border-bottom: var(--edge);
}

.page-about .crumbs {
  margin-bottom: clamp(22px, 5vw, 42px);
  font-size: 13px;
  color: var(--mist);
}

.page-about .eyebrow {
  display: inline-block;
  font-family: var(--font-numeric);
  font-size: 12px;
  font-weight: 700;
  letter-spacing: 0.16em;
  color: var(--signal);
  margin: 0 0 14px;
}

.page-about .about-hero h1 {
  font-family: var(--font-display);
  font-weight: 700;
  letter-spacing: 0.02em;
  font-size: clamp(28px, 5.2vw, 46px);
  line-height: 1.3;
  margin: 0 0 20px;
  max-width: 17em;
  color: var(--cold);
}

.page-about .about-hero .lead {
  font-size: 16px;
  line-height: 1.78;
  color: var(--mist);
  max-width: 34em;
  margin: 0;
}

.page-about .about-facts {
  list-style: none;
  display: flex;
  flex-wrap: wrap;
  gap: clamp(20px, 5vw, 52px);
  margin: clamp(28px, 5vw, 50px) 0 0;
  padding: clamp(20px, 3vw, 30px) 0 0;
  border-top: var(--edge);
}

.page-about .about-facts li {
  min-width: 0;
  max-width: 12em;
}

.page-about .fact-num {
  display: block;
  font-family: var(--font-numeric);
  font-weight: 700;
  font-variant-numeric: tabular-nums;
  font-size: clamp(24px, 4.2vw, 36px);
  line-height: 1.06;
  letter-spacing: 0.01em;
  color: var(--cold);
}

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

/* ---------- 主体网格 ---------- */
.page-about .about-body {
  max-width: var(--wrap);
  margin: 0 auto;
  padding: 0 var(--ab-gutter);
  display: grid;
  grid-template-columns: minmax(0, 1fr);
}

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

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

/* ---------- 小节 ---------- */
.page-about .about-sec {
  padding-block: var(--ab-pad);
  scroll-margin-top: 96px;
}

.page-about .about-sec:first-child {
  padding-top: clamp(36px, 7vw, 72px);
}

.page-about .sec-head {
  display: flex;
  align-items: baseline;
  gap: clamp(12px, 2vw, 18px);
  margin-bottom: clamp(20px, 3.4vw, 34px);
}

.page-about .sec-num {
  flex: 0 0 auto;
  font-family: var(--font-numeric);
  font-weight: 700;
  font-size: 13px;
  letter-spacing: 0.16em;
  font-variant-numeric: tabular-nums;
  color: var(--signal);
}

.page-about .about-sec h2 {
  font-family: var(--font-display);
  font-weight: 700;
  letter-spacing: 0.02em;
  font-size: clamp(23px, 3.9vw, 33px);
  line-height: 1.36;
  margin: 0;
  max-width: 19em;
  color: var(--cold);
}

.page-about .about-sec p {
  font-size: 15px;
  line-height: 1.76;
  color: var(--cold);
  max-width: 38em;
  margin: 0 0 1.15em;
}

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

/* ---------- 数字陈述行 ---------- */
.page-about .figure-list {
  list-style: none;
  margin: clamp(26px, 4.5vw, 42px) 0 0;
  padding: 0;
  border-top: var(--edge);
}

.page-about .figure-list li {
  display: flex;
  align-items: baseline;
  gap: clamp(14px, 3vw, 26px);
  padding: 14px 0;
  border-bottom: var(--edge);
}

.page-about .figure-num {
  flex: 0 0 auto;
  min-width: 4.8em;
  font-family: var(--font-numeric);
  font-weight: 700;
  font-variant-numeric: tabular-nums;
  font-size: clamp(21px, 3.2vw, 29px);
  line-height: 1.14;
  letter-spacing: 0.01em;
  color: var(--signal);
}

.page-about .figure-text {
  font-size: 14px;
  line-height: 1.62;
  color: var(--mist);
}

/* ---------- 四步流程 ---------- */
.page-about .flow {
  list-style: none;
  margin: clamp(26px, 4.5vw, 40px) 0 0;
  padding: 0;
  counter-reset: none;
}

.page-about .flow-item {
  display: grid;
  grid-template-columns: 2.6em minmax(0, 1fr);
  gap: clamp(12px, 3vw, 24px);
  padding: 22px 0;
  border-bottom: var(--edge);
}

.page-about .flow-item:first-child {
  border-top: var(--edge);
}

.page-about .flow-num {
  font-family: var(--font-numeric);
  font-weight: 700;
  font-size: 19px;
  letter-spacing: 0.08em;
  font-variant-numeric: tabular-nums;
  color: var(--mist);
  padding-top: 2px;
}

.page-about .flow-body h3 {
  margin: 0 0 7px;
  font-size: 16px;
  font-weight: 500;
  letter-spacing: 0.01em;
  color: var(--cold);
}

.page-about .flow-body p {
  margin: 0;
  font-size: 14px;
  line-height: 1.72;
  color: var(--mist);
  max-width: 34em;
}

/* ---------- 图片 ---------- */
.page-about .about-figure {
  margin: clamp(30px, 5vw, 52px) 0 0;
}

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

.page-about .media-cap {
  display: block;
  margin-top: 12px;
  font-size: 13px;
  line-height: 1.62;
  color: var(--mist);
  max-width: 34em;
}

.page-about .about-band {
  margin: clamp(8px, 2vw, 20px) 0 clamp(8px, 2vw, 20px);
  padding: 0;
}

.page-about .about-band img {
  display: block;
  width: 100%;
  max-width: 100%;
  height: auto;
  aspect-ratio: 16 / 7;
  object-fit: cover;
  border: var(--edge);
  background: linear-gradient(160deg, var(--plat) 0%, var(--ink) 70%);
}

.page-about .about-band figcaption {
  margin-top: 12px;
  font-size: 13px;
  line-height: 1.62;
  color: var(--mist);
}

/* ---------- 团队 ---------- */
.page-about .crew {
  margin: clamp(26px, 4.5vw, 42px) 0 0;
  border: var(--edge);
  background: var(--car);
}

.page-about .crew-total {
  display: flex;
  align-items: baseline;
  gap: 12px;
  padding: 18px clamp(16px, 3vw, 24px);
  border-bottom: var(--edge);
  background: var(--plat);
}

.page-about .crew-total-num {
  font-family: var(--font-numeric);
  font-weight: 700;
  font-variant-numeric: tabular-nums;
  font-size: clamp(32px, 5vw, 44px);
  line-height: 1;
  color: var(--cold);
}

.page-about .crew-total-label {
  font-size: 14px;
  color: var(--mist);
}

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

.page-about .crew-item {
  position: relative;
  display: block;
  padding: 18px clamp(16px, 3vw, 24px) 18px calc(clamp(16px, 3vw, 24px) + 14px);
  border-bottom: var(--edge);
}

.page-about .crew-item:last-child {
  border-bottom: 0;
}

.page-about .crew-item::before {
  content: "";
  position: absolute;
  left: clamp(16px, 3vw, 24px);
  top: 20px;
  bottom: 20px;
  width: 3px;
  border-radius: var(--r);
}

.page-about .crew-item--data::before {
  background: var(--turf);
}

.page-about .crew-item--write::before {
  background: var(--signal);
}

.page-about .crew-item--front::before {
  background: var(--mist);
}

.page-about .crew-name {
  display: block;
  font-size: 15px;
  font-weight: 500;
  color: var(--cold);
  margin-bottom: 6px;
}

.page-about .crew-desc {
  display: block;
  font-size: 14px;
  line-height: 1.66;
  color: var(--mist);
  max-width: 34em;
}

/* ---------- 版本时间线 ---------- */
.page-about .vtl {
  list-style: none;
  margin: clamp(26px, 4.5vw, 42px) 0 0;
  padding: 0 0 0 22px;
  position: relative;
}

.page-about .vtl::before {
  content: "";
  position: absolute;
  left: 5px;
  top: 10px;
  bottom: 10px;
  width: 1px;
  background: var(--line);
}

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

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

.page-about .vtl-dot {
  position: absolute;
  left: -22px;
  top: 18px;
  width: 11px;
  height: 11px;
  border-radius: 50%;
  background: var(--plat);
  border: 1px solid var(--line);
  box-sizing: border-box;
}

.page-about .vtl-item:last-child .vtl-dot {
  background: var(--signal);
  border-color: var(--signal-soft);
}

.page-about .vtl-card {
  background: var(--car);
  border: var(--edge);
  border-radius: var(--r);
}

.page-about .vtl-card[open] {
  border-color: var(--line);
}

.page-about .vtl-card summary {
  list-style: none;
  cursor: pointer;
  display: flex;
  flex-wrap: wrap;
  align-items: baseline;
  gap: 10px;
  padding: 15px clamp(14px, 3vw, 20px);
}

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

.page-about .vtl-card summary:focus-visible {
  outline: 2px solid var(--signal-soft);
  outline-offset: -2px;
}

.page-about .vtl-ver {
  flex: 0 0 auto;
  font-family: var(--font-numeric);
  font-weight: 700;
  font-size: 12px;
  letter-spacing: 0.12em;
  color: var(--signal);
  border: 1px solid var(--signal);
  border-radius: var(--r);
  padding: 2px 8px;
  line-height: 1.5;
}

.page-about .vtl-name {
  font-size: 15px;
  line-height: 1.6;
  color: var(--cold);
  max-width: 30em;
}

.page-about .vtl-panel {
  padding: 0 clamp(14px, 3vw, 20px) 18px;
}

.page-about .vtl-panel p {
  margin: 0;
  padding-top: 14px;
  border-top: var(--edge);
  font-size: 14px;
  line-height: 1.74;
  color: var(--mist);
  max-width: 34em;
}

/* ---------- 收尾 ---------- */
.page-about .about-next {
  margin-top: clamp(34px, 5.5vw, 56px);
  padding-top: clamp(22px, 3.4vw, 32px);
  border-top: var(--edge);
}

.page-about .about-next p {
  max-width: 34em;
  margin: 0 0 20px;
}

.page-about .about-next .actions {
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
}

/* ---------- 侧栏目录 ---------- */
.page-about .toc-title {
  font-family: var(--font-numeric);
  font-size: 12px;
  font-weight: 700;
  letter-spacing: 0.16em;
  color: var(--mist);
  margin: 0 0 14px;
  padding-bottom: 10px;
  border-bottom: var(--edge);
}

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

.page-about .toc-list li + li {
  margin-top: 2px;
}

.page-about .toc-list a {
  display: block;
  padding: 6px 0 6px 10px;
  font-size: 13px;
  line-height: 1.55;
  color: var(--mist);
  text-decoration: none;
  border-left: 2px solid transparent;
  transition: color 0.18s ease, border-color 0.18s ease;
}

.page-about .toc-list a:hover,
.page-about .toc-list a:focus-visible {
  color: var(--cold);
  border-left-color: var(--signal);
  outline: none;
}

.page-about .toc-list a:focus-visible {
  outline: 2px solid var(--signal-soft);
  outline-offset: 2px;
}

/* ---------- 滚动显现 ---------- */
.page-about .reveal {
  opacity: 0;
  transform: translateY(10px);
  transition: opacity 0.24s ease-out, transform 0.24s ease-out;
  transition-delay: calc(var(--stagger, 0) * 90ms);
}

.page-about .reveal.is-in {
  opacity: 1;
  transform: none;
}

/* ---------- 断点 ---------- */
@media (min-width: 700px) {
  .page-about .about-sec p {
    font-size: 16px;
  }

  .page-about .flow-body p,
  .page-about .crew-desc,
  .page-about .vtl-panel p {
    font-size: 15px;
  }
}

@media (min-width: 1040px) {
  .page-about .about-body {
    grid-template-columns: minmax(0, 720px) var(--ab-toc);
    justify-content: center;
    column-gap: clamp(48px, 6vw, 92px);
  }

  .page-about .about-toc {
    display: block;
    grid-column: 2;
    grid-row: 1;
    align-self: start;
    position: sticky;
    top: 104px;
    padding-top: clamp(36px, 7vw, 72px);
  }
}

@media (min-width: 1280px) {
  .page-about .about-band {
    margin-block: clamp(20px, 3vw, 40px);
  }
}

@media (prefers-reduced-motion: reduce) {
  .page-about .reveal {
    opacity: 1;
    transform: none;
    transition: none;
  }

  .page-about .toc-list a {
    transition: none;
  }
}

.page-about {
  --stagger: 0.3s;
}