.page-about {
  --about-hairline: rgba(124, 140, 156, 0.28);
  --about-body: rgba(245, 247, 246, 0.78);
  overflow-x: clip;
  color: var(--ivory);
}

.page-about .page-about__crumb {
  margin: 0 0 clamp(18px, 3vw, 28px);
}

/* ---------------- 首屏 ---------------- */
.page-about .about-hero {
  display: grid;
  gap: clamp(24px, 4vw, 44px);
  align-items: center;
  padding-bottom: clamp(26px, 4vw, 44px);
}

.page-about .about-hero__kicker {
  display: inline-flex;
  align-items: center;
  gap: 10px;
  margin: 0 0 14px;
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.2em;
  color: var(--cyan);
}

.page-about .about-hero__kicker::before {
  content: "";
  width: 24px;
  height: 2px;
  background: var(--cyan);
}

.page-about .about-hero h1 {
  margin: 0 0 18px;
  font-family: var(--font-display);
  font-weight: 900;
  font-size: clamp(30px, 6.2vw, 54px);
  line-height: 1.1;
  letter-spacing: -0.012em;
  color: var(--ivory);
}

.page-about .about-hero__text {
  margin: 0 0 14px;
  max-width: 38em;
  font-size: clamp(15px, 1.5vw, 16.5px);
  line-height: 1.82;
  color: var(--about-body);
}

.page-about .about-hero__actions {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
  margin-top: 22px;
}

.page-about .about-hero__figure {
  margin: 0;
  border: 1px solid var(--about-hairline);
  background: var(--steel);
  clip-path: polygon(0 0, calc(100% - var(--cut)) 0, 100% var(--cut), 100% 100%, 0 100%);
}

.page-about .about-hero__figure img {
  display: block;
  width: 100%;
  height: auto;
  aspect-ratio: 16 / 9;
  object-fit: cover;
}

.page-about .about-hero__figure figcaption {
  padding: 12px 16px;
  font-size: 13px;
  line-height: 1.65;
  color: var(--slate);
  border-top: 1px solid var(--about-hairline);
}

/* ---------------- 规模条 ---------------- */
.page-about .about-stats {
  display: grid;
  gap: 1px;
  background: var(--about-hairline);
  border: 1px solid var(--about-hairline);
  margin: clamp(28px, 5vw, 52px) 0 clamp(36px, 6vw, 76px);
}

.page-about .about-stats__item {
  position: relative;
  background: var(--steel);
  padding: clamp(20px, 3vw, 28px);
}

.page-about .about-stats__item::before {
  content: "";
  position: absolute;
  left: 0;
  top: 0;
  width: 42px;
  height: 2px;
  background: var(--gold);
}

.page-about .about-stats__num {
  display: block;
  font-size: clamp(32px, 5vw, 46px);
  font-weight: 700;
  line-height: 1;
  color: var(--cyan);
  font-variant-numeric: tabular-nums;
}

.page-about .about-stats__unit {
  display: block;
  margin-top: 10px;
  font-family: var(--font-display);
  font-size: 16px;
  font-weight: 800;
  color: var(--ivory);
}

.page-about .about-stats__item p {
  margin: 10px 0 0;
  font-size: 13.5px;
  line-height: 1.72;
  color: var(--slate);
}

/* ---------------- 区块通用 ---------------- */
.page-about .about-block {
  padding: clamp(34px, 6vw, 70px) 0;
  border-top: 1px solid var(--about-hairline);
}

.page-about .about-block__head {
  max-width: 46em;
  margin-bottom: clamp(22px, 4vw, 38px);
}

.page-about .about-block__kicker {
  display: block;
  margin: 0 0 10px;
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.18em;
  color: var(--gold);
}

.page-about .about-block__title {
  margin: 0 0 12px;
  font-family: var(--font-display);
  font-weight: 800;
  font-size: clamp(23px, 3.6vw, 34px);
  line-height: 1.22;
  color: var(--ivory);
}

.page-about .about-block__lede {
  margin: 0;
  max-width: 40em;
  font-size: 15px;
  line-height: 1.82;
  color: var(--about-body);
}

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

.page-about .about-timeline__list::before {
  content: "";
  position: absolute;
  left: 5px;
  top: 12px;
  bottom: 12px;
  width: 1px;
  background: linear-gradient(180deg, var(--gold), rgba(124, 140, 156, 0.32) 55%, rgba(124, 140, 156, 0));
}

.page-about .about-timeline__item {
  position: relative;
  padding-left: 30px;
}

.page-about .about-timeline__item + .about-timeline__item {
  margin-top: 8px;
}

.page-about .about-timeline__item::before {
  content: "";
  position: absolute;
  left: 0;
  top: 25px;
  width: 11px;
  height: 11px;
  background: var(--gold);
  transform: rotate(45deg);
}

.page-about .about-timeline__node {
  border: 1px solid var(--about-hairline);
  background: linear-gradient(180deg, rgba(22, 40, 60, 0.88), rgba(11, 22, 34, 0.72));
  transition: border-color var(--speed) linear;
}

.page-about .about-timeline__node[open] {
  border-color: rgba(242, 178, 60, 0.5);
}

.page-about .about-timeline__node summary {
  display: grid;
  grid-template-columns: auto minmax(0, 1fr) auto;
  align-items: center;
  gap: 14px;
  padding: 16px 18px;
  cursor: pointer;
  list-style: none;
}

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

.page-about .about-timeline__node summary:focus-visible {
  outline: 2px solid var(--cyan);
  outline-offset: -2px;
}

.page-about .about-timeline__node summary::after {
  content: "";
  width: 8px;
  height: 8px;
  border-right: 2px solid var(--cyan);
  border-bottom: 2px solid var(--cyan);
  transform: rotate(45deg) translate(-2px, -2px);
  transition: transform var(--speed) linear;
}

.page-about .about-timeline__node[open] summary::after {
  transform: rotate(-135deg) translate(-2px, -2px);
}

.page-about .about-timeline__year {
  font-size: 12.5px;
  letter-spacing: 0.06em;
  color: var(--gold);
  white-space: nowrap;
}

.page-about .about-timeline__title {
  font-size: 15.5px;
  font-weight: 600;
  line-height: 1.5;
  color: var(--ivory);
}

.page-about .about-timeline__body {
  padding: 0 18px 18px;
  border-top: 1px solid var(--about-hairline);
  margin-top: 2px;
  padding-top: 14px;
}

.page-about .about-timeline__body p {
  margin: 0;
  max-width: 44em;
  font-size: 14.5px;
  line-height: 1.8;
  color: var(--about-body);
}

.page-about .about-timeline__more {
  margin: 22px 0 0;
  font-size: 14px;
  line-height: 1.7;
  color: var(--slate);
}

.page-about .about-timeline__more a {
  color: var(--cyan);
  text-decoration: none;
  border-bottom: 1px solid rgba(53, 240, 208, 0.4);
}

.page-about .about-timeline__more a:focus-visible {
  outline: 2px solid var(--cyan);
  outline-offset: 3px;
}

/* ---------------- 团队分工 ---------------- */
.page-about .about-crew__grid {
  display: grid;
  gap: 16px;
}

.page-about .about-crew__card {
  padding: clamp(22px, 3vw, 30px);
  background: var(--paper);
  color: var(--ink);
  clip-path: polygon(0 0, calc(100% - var(--cut)) 0, 100% var(--cut), 100% 100%, 0 100%);
  transition: transform var(--speed) linear, box-shadow var(--speed) linear;
}

.page-about .about-crew__count {
  display: block;
  font-size: clamp(34px, 5vw, 42px);
  font-weight: 700;
  line-height: 1;
  color: var(--ink);
  font-variant-numeric: tabular-nums;
}

.page-about .about-crew__role {
  margin: 10px 0 10px;
  font-family: var(--font-display);
  font-size: 20px;
  font-weight: 800;
  color: var(--ink);
}

.page-about .about-crew__desc {
  margin: 0 0 16px;
  font-size: 14px;
  line-height: 1.78;
  color: rgba(20, 17, 15, 0.76);
}

.page-about .about-crew__duties {
  margin: 0;
  padding: 14px 0 0;
  list-style: none;
  border-top: 1px solid rgba(20, 17, 15, 0.16);
}

.page-about .about-crew__duties li {
  position: relative;
  padding-left: 15px;
  font-size: 13.5px;
  line-height: 1.95;
  color: rgba(20, 17, 15, 0.68);
}

.page-about .about-crew__duties li::before {
  content: "";
  position: absolute;
  left: 0;
  top: 12px;
  width: 7px;
  height: 1px;
  background: rgba(20, 17, 15, 0.42);
}

.page-about .about-crew__note {
  margin: 24px 0 0;
  padding: 14px 18px;
  max-width: 52em;
  font-size: 13.8px;
  line-height: 1.8;
  color: rgba(245, 247, 246, 0.8);
  background: rgba(53, 240, 208, 0.06);
  border-left: 2px solid var(--cyan);
}

/* ---------------- 资料来源 ---------------- */
.page-about .about-sources__grid {
  display: grid;
  gap: clamp(24px, 4vw, 44px);
  align-items: start;
}

.page-about .about-sources__list {
  margin: 24px 0;
  padding: 0;
  list-style: none;
  display: grid;
  gap: 1px;
  background: var(--about-hairline);
  border: 1px solid var(--about-hairline);
}

.page-about .about-sources__row {
  display: grid;
  gap: 10px;
  padding: 18px 20px;
  background: var(--ink);
}

.page-about .about-sources__row p {
  margin: 0;
  font-size: 14.5px;
  line-height: 1.78;
  color: var(--about-body);
}

.page-about .about-sources__figure {
  margin: 0;
  padding: 10px;
  border: 1px solid var(--about-hairline);
  background: var(--steel);
  clip-path: polygon(0 0, 100% 0, 100% calc(100% - var(--cut)), calc(100% - var(--cut)) 100%, 0 100%);
}

.page-about .about-sources__figure img {
  display: block;
  width: 100%;
  height: auto;
  aspect-ratio: 14 / 9;
  object-fit: cover;
}

.page-about .about-sources__figure figcaption {
  padding: 12px 6px 4px;
  font-size: 13px;
  line-height: 1.65;
  color: var(--slate);
}

/* ---------------- 校验流程 ---------------- */
.page-about .about-check__grid {
  display: grid;
  gap: clamp(24px, 4vw, 44px);
  align-items: start;
}

.page-about .about-check__figure {
  margin: 0;
  border: 1px solid var(--about-hairline);
  background: var(--steel);
  clip-path: polygon(0 0, calc(100% - var(--cut)) 0, 100% var(--cut), 100% 100%, 0 100%);
}

.page-about .about-check__figure img {
  display: block;
  width: 100%;
  height: auto;
  aspect-ratio: 3 / 2;
  object-fit: cover;
}

.page-about .about-check__figure figcaption {
  padding: 12px 16px;
  font-size: 13px;
  line-height: 1.65;
  color: var(--slate);
  border-top: 1px solid var(--about-hairline);
}

.page-about .about-check__steps {
  position: relative;
  padding-left: 30px;
}

.page-about .about-check__svg {
  position: absolute;
  left: 0;
  top: 0;
  width: 24px;
  height: 100%;
  pointer-events: none;
}

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

.page-about .about-check__step {
  padding: 16px 18px;
  border: 1px solid var(--about-hairline);
  background: var(--ink);
  transition: border-color var(--speed) linear, background var(--speed) linear;
}

.page-about .about-check__step:hover {
  border-color: rgba(53, 240, 208, 0.45);
  background: rgba(22, 40, 60, 0.6);
}

.page-about .about-check__step:focus-visible {
  outline: 2px solid var(--cyan);
  outline-offset: 2px;
}

.page-about .about-check__idx {
  display: inline-block;
  font-size: 12px;
  letter-spacing: 0.12em;
  color: var(--cyan);
}

.page-about .about-check__step h3 {
  margin: 6px 0 8px;
  font-family: var(--font-display);
  font-size: 18px;
  font-weight: 800;
  color: var(--ivory);
}

.page-about .about-check__step p {
  margin: 0;
  font-size: 14.5px;
  line-height: 1.78;
  color: var(--about-body);
}

.page-about .about-check__note {
  margin: 24px 0 0;
  padding: 14px 18px;
  max-width: 52em;
  font-size: 14px;
  line-height: 1.78;
  color: rgba(245, 247, 246, 0.84);
  background: rgba(255, 61, 110, 0.08);
  border-left: 2px solid var(--rose);
}

/* ---------------- 编号与版本 ---------------- */
.page-about .about-code__grid {
  display: grid;
  gap: 16px;
}

.page-about .about-code__card {
  padding: clamp(22px, 3vw, 32px);
  border: 1px solid var(--about-hairline);
  background: var(--steel);
  clip-path: polygon(0 0, 100% 0, 100% calc(100% - var(--cut)), calc(100% - var(--cut)) 100%, 0 100%);
}

.page-about .about-code__card--paper {
  background: var(--paper);
  border-color: transparent;
}

.page-about .about-code__card--paper .about-code__formula,
.page-about .about-code__card--paper p {
  color: var(--ink);
}

.page-about .about-code__card--paper p {
  color: rgba(20, 17, 15, 0.78);
}

.page-about .about-code__formula {
  margin: 14px 0 14px;
  font-family: var(--font-mono);
  font-size: clamp(17px, 2.4vw, 22px);
  font-weight: 700;
  letter-spacing: 0.04em;
  color: var(--cyan);
  font-variant-numeric: tabular-nums;
}

.page-about .about-code__card p {
  margin: 0;
  font-size: 14.5px;
  line-height: 1.8;
  color: var(--about-body);
}

/* ---------------- 协作与联系 ---------------- */
.page-about .about-join__panel {
  display: grid;
  gap: clamp(24px, 4vw, 44px);
  padding: clamp(24px, 4vw, 44px);
  border: 1px solid var(--line-strong);
  background:
    linear-gradient(135deg, rgba(53, 240, 208, 0.08), transparent 46%),
    linear-gradient(315deg, rgba(242, 178, 60, 0.08), transparent 52%),
    var(--char);
  clip-path: polygon(0 var(--cut), var(--cut) 0, 100% 0, 100% calc(100% - var(--cut)), calc(100% - var(--cut)) 100%, 0 100%);
}

.page-about .about-join__actions {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
  margin-top: 24px;
}

.page-about .about-join__contact h3 {
  margin: 0 0 16px;
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.18em;
  color: var(--gold);
}

.page-about .about-join__dl {
  margin: 0;
  display: grid;
  gap: 14px;
}

.page-about .about-join__dl dt {
  margin-bottom: 4px;
  font-size: 12px;
  letter-spacing: 0.06em;
  color: var(--slate);
}

.page-about .about-join__dl dd {
  margin: 0;
  font-size: 14px;
  line-height: 1.68;
  color: var(--ivory);
  overflow-wrap: anywhere;
}

/* ---------------- 响应式 ---------------- */
@media (min-width: 560px) {
  .page-about .about-sources__row {
    grid-template-columns: 108px minmax(0, 1fr);
    align-items: start;
    gap: 18px;
  }
}

@media (min-width: 700px) {
  .page-about .about-stats {
    grid-template-columns: repeat(3, minmax(0, 1fr));
  }
}

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

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

@media (min-width: 900px) {
  .page-about .about-join__panel {
    grid-template-columns: minmax(0, 7fr) minmax(0, 5fr);
  }
}

@media (min-width: 960px) {
  .page-about .about-hero {
    grid-template-columns: minmax(0, 7fr) minmax(0, 5fr);
    gap: clamp(32px, 4vw, 64px);
  }

  .page-about .about-sources__grid {
    grid-template-columns: minmax(0, 7fr) minmax(0, 5fr);
  }

  .page-about .about-check__grid {
    grid-template-columns: minmax(0, 5fr) minmax(0, 7fr);
  }
}

@media (hover: hover) {
  .page-about .about-crew__card:hover {
    transform: translateY(-3px);
    box-shadow: var(--shadow-2);
  }
}

@media (prefers-reduced-motion: reduce) {
  .page-about .about-crew__card,
  .page-about .about-timeline__node,
  .page-about .about-timeline__node summary::after,
  .page-about .about-check__step {
    transition: none;
  }

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