.page-about {
  --about-hair: #C4CBD8;
  --about-hair-soft: rgba(196, 203, 216, .55);
  --about-dark-hair: rgba(244, 247, 255, .18);
  --about-ink-soft: #232838;
  background: var(--lt-ice);
  color: var(--lt-black);
}

/* ---------- 首屏 ---------- */
.page-about .about-hero {
  position: relative;
  overflow: hidden;
  background: var(--lt-black);
  color: #FFFFFF;
  padding: 26px 0 44px;
}
.page-about .about-hero .shell {
  position: relative;
  z-index: 1;
}
.page-about .about-hero .crumb__link {
  color: var(--lt-silver);
  background-image: none;
}
.page-about .about-hero .crumb__link[aria-current="page"] {
  color: var(--lt-yellow);
}
.page-about .about-hero .crumb__sep {
  color: var(--lt-slate);
}

.page-about .about-hero__grid {
  display: grid;
  gap: 32px;
  margin-top: 26px;
}
.page-about .about-hero__eyebrow {
  margin: 0 0 14px;
  font-family: var(--lt-font-mono);
  font-size: 12px;
  letter-spacing: .08em;
  color: var(--lt-yellow);
}
.page-about .about-hero h1 {
  margin: 0 0 18px;
  font-family: var(--lt-font-display);
  font-weight: 900;
  font-size: clamp(32px, 6vw, 62px);
  line-height: 1.08;
  letter-spacing: -.01em;
}
.page-about .about-hero__lede {
  margin: 0 0 26px;
  max-width: 40em;
  font-size: 16px;
  line-height: 1.8;
  color: var(--lt-silver);
}
.page-about .about-hero__actions {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
}

.page-about .about-hero__stats {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 1px;
  margin: 0;
  background: var(--about-dark-hair);
  border: 1px solid var(--about-dark-hair);
}
.page-about .about-stat {
  background: var(--lt-black);
  padding: 16px 14px;
}
.page-about .about-stat dt {
  font-size: 12px;
  letter-spacing: .04em;
  color: var(--lt-silver);
}
.page-about .about-stat dd {
  margin: 8px 0 0;
  font-size: 16px;
  font-weight: 700;
  line-height: 1.4;
}
.page-about .about-stat .lt-num {
  font-family: var(--lt-font-mono);
  font-size: 1.5em;
  color: var(--lt-yellow);
}

/* ---------- 主体骨架 ---------- */
.page-about .about-body {
  padding: 40px 0 0;
}
.page-about .about-layout {
  display: grid;
  gap: 32px;
}
.page-about .about-main {
  min-width: 0;
}

.page-about .about-toc {
  display: none;
}
.page-about .about-toc__title {
  margin: 0 0 12px;
  font-family: var(--lt-font-mono);
  font-size: 12px;
  letter-spacing: .08em;
  color: var(--lt-slate);
}
.page-about .about-toc__list {
  list-style: none;
  margin: 0;
  padding: 0;
}

/* ---------- 章节通用 ---------- */
.page-about .about-section {
  padding-bottom: 52px;
}
.page-about .about-section + .about-section {
  border-top: 1px solid var(--about-hair-soft);
  padding-top: 44px;
}
.page-about .about-h2 {
  margin: 14px 0 16px;
  font-family: var(--lt-font-serif);
  font-weight: 600;
  font-size: clamp(23px, 3.4vw, 33px);
  line-height: 1.28;
}
.page-about .about-p {
  margin: 0 0 16px;
  max-width: 40em;
  font-size: 16px;
  line-height: 1.8;
  color: var(--about-ink-soft);
}
.page-about .about-p--note {
  font-size: 14.5px;
  color: var(--lt-slate);
}

/* ---------- 时间线 ---------- */
.page-about .about-timeline {
  position: relative;
  list-style: none;
  margin: 28px 0 0;
  padding: 0;
}
.page-about .about-timeline::before {
  content: "";
  position: absolute;
  left: 7px;
  top: 12px;
  bottom: 12px;
  width: 1px;
  background: var(--about-hair);
}
.page-about .about-timeline > li {
  position: relative;
  padding-left: 34px;
  margin-bottom: 12px;
}
.page-about .about-timeline > li:last-child {
  margin-bottom: 0;
}
.page-about .about-timeline > li::before {
  content: "";
  position: absolute;
  left: 0;
  top: 18px;
  width: 15px;
  height: 15px;
  background: var(--lt-blue);
  border: 1px solid var(--lt-blue);
}
.page-about .about-timeline > li:nth-child(even)::before {
  background: var(--lt-yellow);
  border-color: var(--lt-black);
}
.page-about .about-timeline details {
  position: relative;
  background: #FFFFFF;
  border: 1px solid var(--about-hair-soft);
  transition: border-color .16s var(--lt-ease);
}
.page-about .about-timeline details::after {
  content: "";
  position: absolute;
  left: -1px;
  top: -1px;
  bottom: -1px;
  width: 4px;
  background: var(--lt-yellow);
  transform: scaleY(0);
  transform-origin: top;
  transition: transform .16s var(--lt-ease);
}
.page-about .about-timeline details:hover::after,
.page-about .about-timeline details[open]::after {
  transform: scaleY(1);
}
.page-about .about-timeline details:hover,
.page-about .about-timeline details[open] {
  border-color: var(--lt-blue);
}
.page-about .about-timeline summary {
  display: flex;
  flex-wrap: wrap;
  align-items: baseline;
  gap: 12px;
  padding: 14px 16px;
  cursor: pointer;
  list-style: none;
}
.page-about .about-timeline summary::-webkit-details-marker {
  display: none;
}
.page-about .about-timeline__season {
  font-family: var(--lt-font-mono);
  font-size: 12px;
  letter-spacing: .06em;
  padding: 3px 8px;
  background: var(--lt-blue);
  color: #FFFFFF;
}
.page-about .about-timeline__title {
  flex: 1 1 180px;
  font-size: 16.5px;
  font-weight: 700;
  line-height: 1.5;
}
.page-about .about-timeline__text {
  margin: 0;
  padding: 0 16px 16px;
  max-width: 44em;
  font-size: 15px;
  line-height: 1.8;
  color: var(--about-ink-soft);
}

/* ---------- 四类内容 ---------- */
.page-about .about-needs {
  list-style: none;
  margin: 26px 0 0;
  padding: 0;
  display: grid;
  gap: 16px;
}
.page-about .about-need {
  height: 100%;
}
.page-about .about-need .card__title {
  font-size: 19px;
}
.page-about .about-need .card__text {
  margin: 0;
  font-size: 15px;
  line-height: 1.75;
  color: var(--lt-slate);
}

/* ---------- 球队档案 ---------- */
.page-about .about-file {
  display: grid;
  gap: 28px;
  margin-top: 24px;
}
.page-about .about-file__list {
  min-width: 0;
}
.page-about .about-file__item {
  border-top: 1px solid var(--about-hair-soft);
}
.page-about .about-file__item:last-child {
  border-bottom: 1px solid var(--about-hair-soft);
}
.page-about .about-file__item summary {
  display: flex;
  align-items: center;
  gap: 14px;
  padding: 16px 2px;
  cursor: pointer;
  list-style: none;
  transition: background-color .16s var(--lt-ease);
}
.page-about .about-file__item summary::-webkit-details-marker {
  display: none;
}
.page-about .about-file__item summary:hover {
  background: var(--lt-concrete);
}
.page-about .about-file__item[open] summary {
  background: var(--lt-concrete);
}
.page-about .about-file__idx {
  flex: 0 0 auto;
  width: 24px;
  height: 24px;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  font-family: var(--lt-font-mono);
  font-size: 12px;
  background: var(--lt-blue);
  color: #FFFFFF;
}
.page-about .about-file__item:nth-child(even) .about-file__idx {
  background: var(--lt-yellow);
  color: var(--lt-black);
}
.page-about .about-file__name {
  font-size: 17px;
  font-weight: 700;
}
.page-about .about-file__item > p {
  margin: 0;
  padding: 0 2px 18px 38px;
  max-width: 40em;
  font-size: 15px;
  line-height: 1.8;
  color: var(--about-ink-soft);
}

.page-about .about-figure {
  margin: 0;
}
.page-about .about-figure figcaption {
  margin-top: 10px;
  font-size: 13px;
  line-height: 1.7;
  color: var(--lt-slate);
}

/* ---------- 生产流程 ---------- */
.page-about .about-steps {
  list-style: none;
  margin: 26px 0 0;
  padding: 0;
  display: grid;
  gap: 22px;
}
.page-about .about-step {
  border-top: 2px solid var(--lt-blue);
  padding-top: 14px;
}
.page-about .about-step:last-child {
  border-top-color: var(--lt-yellow);
}
.page-about .about-step__num {
  display: block;
  font-family: var(--lt-font-mono);
  font-size: 12px;
  letter-spacing: .1em;
  color: var(--lt-blue);
}
.page-about .about-step:last-child .about-step__num {
  color: var(--lt-black);
}
.page-about .about-step h3 {
  margin: 8px 0 8px;
  font-size: 18px;
  font-weight: 800;
}
.page-about .about-step p {
  margin: 0;
  font-size: 15px;
  line-height: 1.75;
  color: var(--about-ink-soft);
}

.page-about .about-figure--wide {
  margin-top: 30px;
}

/* ---------- 引用色带 ---------- */
.page-about .about-quote {
  position: relative;
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  justify-content: space-between;
  gap: 18px;
  margin-top: 32px;
  padding: 28px 24px 28px 30px;
  background: var(--lt-blue);
  color: #FFFFFF;
}
.page-about .about-quote::before {
  content: "";
  position: absolute;
  left: 0;
  top: 0;
  bottom: 0;
  width: 6px;
  background: var(--lt-yellow);
}
.page-about .about-quote__text {
  margin: 0;
  font-family: var(--lt-font-serif);
  font-weight: 600;
  font-size: clamp(18px, 2.4vw, 25px);
  line-height: 1.45;
}
.page-about .about-quote .copy-btn {
  flex: 0 0 auto;
  min-height: 44px;
  border-color: rgba(255, 255, 255, .55);
  color: #FFFFFF;
  transition: border-color .16s var(--lt-ease), color .16s var(--lt-ease);
}
.page-about .about-quote .copy-btn:hover {
  border-color: var(--lt-yellow);
  color: var(--lt-yellow);
}

/* ---------- 团队 ---------- */
.page-about .about-team {
  list-style: none;
  margin: 26px 0 0;
  padding: 0;
  display: grid;
  gap: 1px;
  background: var(--about-hair-soft);
  border: 1px solid var(--about-hair-soft);
}
.page-about .about-team__item {
  display: flex;
  gap: 16px;
  padding: 20px 18px;
  background: #FFFFFF;
}
.page-about .about-team__num {
  flex: 0 0 auto;
  font-family: var(--lt-font-mono);
  font-size: 28px;
  line-height: 1;
  color: var(--lt-blue);
}
.page-about .about-team__item h3 {
  margin: 0 0 6px;
  font-size: 16px;
  font-weight: 800;
}
.page-about .about-team__item p {
  margin: 0;
  font-size: 14.5px;
  line-height: 1.75;
  color: var(--about-ink-soft);
}
.page-about .about-team + .about-p--note {
  margin-top: 18px;
}

/* ---------- 上海视角 ---------- */
.page-about .about-shanghai {
  margin-top: 22px;
  background: var(--lt-night);
  color: #FFFFFF;
}
.page-about .about-shanghai__body {
  padding: 26px 22px 30px;
}
.page-about .about-shanghai__body p {
  margin: 0 0 16px;
  max-width: 40em;
  font-size: 15.5px;
  line-height: 1.8;
  color: var(--lt-silver);
}
.page-about .about-shanghai__stats {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(140px, 1fr));
  gap: 1px;
  margin: 22px 0 0;
  background: var(--about-dark-hair);
  border: 1px solid var(--about-dark-hair);
}
.page-about .about-shanghai__stats > div {
  background: var(--lt-night);
  padding: 14px;
}
.page-about .about-shanghai__stats dt {
  font-size: 12px;
  color: var(--lt-silver);
}
.page-about .about-shanghai__stats dd {
  margin: 8px 0 0;
  font-size: 15px;
  font-weight: 700;
}
.page-about .about-shanghai__stats .lt-num {
  font-family: var(--lt-font-mono);
  font-size: 1.45em;
  color: var(--lt-yellow);
}

/* ---------- 伙伴与认可 ---------- */
.page-about .about-miles {
  list-style: none;
  margin: 26px 0 0;
  padding: 0;
  display: grid;
  gap: 16px;
}
.page-about .about-mile {
  border-left: 4px solid var(--lt-blue);
  padding: 4px 0 4px 16px;
}
.page-about .about-mile:nth-child(2) {
  border-left-color: var(--lt-cyan);
}
.page-about .about-mile:nth-child(3) {
  border-left-color: var(--lt-yellow);
}
.page-about .about-mile__num {
  display: block;
  font-family: var(--lt-font-mono);
  font-size: 30px;
  line-height: 1;
  color: var(--lt-blue);
}
.page-about .about-mile h3 {
  margin: 8px 0 6px;
  font-size: 16.5px;
  font-weight: 800;
}
.page-about .about-mile p {
  margin: 0;
  font-size: 14.5px;
  line-height: 1.75;
  color: var(--about-ink-soft);
}
.page-about .about-miles + .about-p--note {
  margin-top: 22px;
}

/* ---------- 后续入口 ---------- */
.page-about .about-next {
  margin-top: 8px;
  padding: 34px 22px 38px;
  background: var(--lt-concrete);
}
.page-about .about-next__title {
  margin: 0 0 18px;
  font-family: var(--lt-font-serif);
  font-weight: 600;
  font-size: clamp(20px, 2.6vw, 26px);
}
.page-about .about-next__list {
  list-style: none;
  margin: 0;
  padding: 0;
  display: grid;
  gap: 1px;
  background: #FFFFFF;
}
.page-about .about-next__list a {
  display: block;
  padding: 16px 18px;
  background: #FFFFFF;
  text-decoration: none;
  color: var(--lt-black);
  transition: background-color .16s var(--lt-ease), color .16s var(--lt-ease);
}
.page-about .about-next__list a:hover {
  background: var(--lt-blue);
  color: #FFFFFF;
}
.page-about .about-next__name {
  display: block;
  font-size: 17px;
  font-weight: 800;
}
.page-about .about-next__desc {
  display: block;
  margin-top: 4px;
  font-size: 14px;
  line-height: 1.7;
  color: var(--lt-slate);
}
.page-about .about-next__list a:hover .about-next__desc {
  color: var(--lt-silver);
}

/* ---------- 断点 ---------- */
@media (min-width: 640px) {
  .page-about .about-hero {
    padding: 34px 0 56px;
  }
  .page-about .about-hero__stats {
    grid-template-columns: repeat(4, minmax(0, 1fr));
  }
  .page-about .about-shanghai__body {
    padding: 30px 28px 34px;
  }
  .page-about .about-next {
    padding: 40px 32px 44px;
  }
}

@media (min-width: 760px) {
  .page-about .about-needs {
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }
  .page-about .about-steps {
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }
  .page-about .about-team {
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }
  .page-about .about-miles {
    grid-template-columns: repeat(3, minmax(0, 1fr));
  }
  .page-about .about-next__list {
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }
}

@media (min-width: 900px) {
  .page-about .about-hero__grid {
    grid-template-columns: 7fr 5fr;
    gap: 48px;
    align-items: end;
  }
  .page-about .about-file {
    grid-template-columns: 7fr 5fr;
    gap: 32px;
    align-items: start;
  }
  .page-about .about-steps {
    grid-template-columns: repeat(4, minmax(0, 1fr));
    gap: 20px;
  }
}

@media (min-width: 1080px) {
  .page-about .about-body {
    padding: 56px 0 0;
  }
  .page-about .about-layout {
    grid-template-columns: 190px minmax(0, 1fr);
    gap: 56px;
  }
  .page-about .about-toc {
    display: block;
    position: sticky;
    top: 28px;
    align-self: start;
  }
  .page-about .about-toc__list a {
    display: block;
    padding: 9px 0 9px 14px;
    border-left: 1px solid var(--about-hair-soft);
    font-size: 14px;
    line-height: 1.5;
    color: var(--lt-slate);
    text-decoration: none;
    transition: border-color .16s var(--lt-ease), color .16s var(--lt-ease);
  }
  .page-about .about-toc__list a:hover,
  .page-about .about-toc__list a:focus-visible {
    border-left-color: var(--lt-yellow);
    color: var(--lt-black);
  }
  .page-about .about-needs {
    grid-template-columns: repeat(4, minmax(0, 1fr));
  }
  .page-about .about-needs > li:nth-child(even) {
    margin-top: 32px;
  }
  .page-about .about-section {
    padding-bottom: 64px;
  }
  .page-about .about-section + .about-section {
    padding-top: 56px;
  }
}

@media (prefers-reduced-motion: reduce) {
  .page-about .about-timeline details::after,
  .page-about .about-timeline details,
  .page-about .about-file__item summary,
  .page-about .about-next__list a,
  .page-about .about-quote .copy-btn,
  .page-about .about-toc__list a {
    transition: none;
  }
  .page-about .about-timeline details::after {
    transform: scaleY(1);
    opacity: 0;
  }
  .page-about .about-timeline details:hover::after,
  .page-about .about-timeline details[open]::after {
    opacity: 1;
  }
}