.page-about {
  --about-gap: clamp(56px, 8vw, 104px);
  --rail-w: 208px;
  --anchor-offset: calc(var(--header-h) + var(--strip-h) + 24px);
  padding-top: calc(var(--header-h) + var(--strip-h) + 4px);
  padding-bottom: clamp(60px, 9vw, 120px);
}

.page-about .about-crumb {
  padding-bottom: 20px;
}

/* ---------- 首屏 ---------- */

.page-about .about-hero {
  position: relative;
  overflow: hidden;
  padding: 26px 0 clamp(34px, 5vw, 62px);
}

.page-about .about-hero::before {
  content: "";
  position: absolute;
  top: -60px;
  right: -12%;
  width: min(760px, 66vw);
  height: 130%;
  background: linear-gradient(158deg, rgba(52, 242, 206, 0.16), rgba(52, 242, 206, 0) 64%);
  clip-path: polygon(20% 0, 100% 0, 100% 100%, 0 84%);
  pointer-events: none;
  z-index: 0;
}

.page-about .about-hero__grid {
  position: relative;
  z-index: 1;
  align-items: start;
}

.page-about .about-hero__title {
  margin: 16px 0 0;
  font-family: var(--ff-display);
  font-weight: 300;
  font-size: clamp(38px, 6.6vw, 84px);
  line-height: 0.98;
  letter-spacing: 0.02em;
  color: var(--paper);
}

.page-about .about-hero__title-sub {
  display: block;
  margin-top: 10px;
  font-size: clamp(22px, 3.2vw, 40px);
  letter-spacing: 0.06em;
  color: var(--cyan-soft);
}

.page-about .about-hero__text {
  max-width: 52ch;
  margin-top: 22px;
  color: var(--muted);
}

.page-about .about-hero__acts {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
  margin-top: 26px;
}

.page-about .about-hero__media {
  margin-top: 26px;
}

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

/* ---------- 铭牌区 ---------- */

.page-about .about-plaque {
  border-top: 1px solid var(--line);
  border-bottom: 1px solid var(--line);
  background: linear-gradient(180deg, rgba(14, 42, 36, 0.78), rgba(6, 23, 19, 0.35));
  padding: clamp(22px, 3vw, 34px) 0;
  margin-bottom: clamp(40px, 6vw, 76px);
}

.page-about .about-plaque__grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: 1px;
  background: var(--line);
  border: 1px solid var(--line);
}

.page-about .plaque {
  position: relative;
  background: var(--ink-800);
  padding: 20px 18px 22px;
  min-height: 118px;
  display: flex;
  flex-direction: column;
  gap: 8px;
}

.page-about .plaque::before {
  content: "";
  position: absolute;
  top: 0;
  left: 0;
  width: 36px;
  height: 2px;
  background: var(--cyan);
}

.page-about .plaque__key {
  font-family: var(--ff-body);
  font-size: 12px;
  letter-spacing: 0.16em;
  color: var(--muted);
}

.page-about .plaque__value {
  font-family: var(--ff-mono);
  font-variant-numeric: tabular-nums;
  font-size: clamp(17px, 1.8vw, 22px);
  line-height: 1.3;
  color: var(--paper);
  word-break: break-word;
}

.page-about .plaque__value--accent {
  color: var(--cyan);
}

.page-about .plaque__note {
  font-size: 13px;
  line-height: 1.6;
  color: var(--muted);
  margin-top: auto;
}

/* ---------- 主体非对称分栏 ---------- */

.page-about .about-body {
  display: grid;
  grid-template-columns: 1fr;
  gap: 36px;
}

.page-about .about-rail__title {
  font-size: 12px;
  letter-spacing: 0.16em;
  color: var(--muted);
  margin-bottom: 12px;
}

.page-about .about-rail__list {
  list-style: none;
  margin: 0;
  padding: 0;
  display: flex;
  flex-wrap: wrap;
  gap: 4px 16px;
}

.page-about .about-rail__list a {
  display: flex;
  align-items: baseline;
  gap: 9px;
  padding: 7px 2px;
  border-bottom: 1px solid var(--line);
  font-size: 14px;
  color: var(--muted);
  text-decoration: none;
  transition: color var(--ease), border-color var(--ease), background var(--ease);
}

.page-about .about-rail__list a:hover,
.page-about .about-rail__list a:focus-visible {
  color: var(--cyan-soft);
  border-bottom-color: var(--cyan);
}

.page-about .about-rail__list a.is-active {
  color: var(--cyan);
  border-bottom-color: var(--cyan);
}

.page-about .about-rail__no {
  font-size: 11px;
  letter-spacing: 0.1em;
  color: var(--line);
}

.page-about .about-rail__list a.is-active .about-rail__no,
.page-about .about-rail__list a:hover .about-rail__no {
  color: var(--orange);
}

/* ---------- 章节通用 ---------- */

.page-about .about-sec {
  scroll-margin-top: var(--anchor-offset);
}

.page-about .about-sec + .about-sec {
  margin-top: var(--about-gap);
}

.page-about .about-sec__head {
  max-width: 62ch;
}

.page-about .about-sec__title {
  margin-top: 12px;
  font-family: var(--ff-display);
  font-weight: 300;
  font-size: clamp(24px, 3.4vw, 40px);
  line-height: 1.16;
  letter-spacing: 0.04em;
  color: var(--paper);
}

.page-about .about-sec__desc {
  margin-top: 14px;
  font-size: 16px;
  line-height: 1.78;
  color: var(--muted);
}

.page-about .about-sec__foot {
  margin-top: 26px;
  font-size: 14px;
  line-height: 1.75;
  color: var(--muted);
}

.page-about .about-sec__foot a {
  color: var(--cyan);
  text-decoration: none;
  border-bottom: 1px solid var(--line);
  transition: border-color var(--ease);
}

.page-about .about-sec__foot a:hover {
  border-bottom-color: var(--cyan);
}

/* ---------- 历程时间线 ---------- */

.page-about .timeline {
  list-style: none;
  margin: 34px 0 0;
  padding: 0 0 0 28px;
  border-left: 1px solid var(--line);
}

.page-about .timeline__item {
  position: relative;
}

.page-about .timeline__item:nth-child(1) { margin-top: 4px; }
.page-about .timeline__item:nth-child(2) { margin-top: 38px; }
.page-about .timeline__item:nth-child(3) { margin-top: 16px; }
.page-about .timeline__item:nth-child(4) { margin-top: 48px; }
.page-about .timeline__item:nth-child(5) { margin-top: 22px; }

.page-about .timeline__item::before {
  content: "";
  position: absolute;
  top: 7px;
  left: -33px;
  width: 9px;
  height: 9px;
  background: var(--ink-900);
  border: 1px solid var(--cyan);
  transform: rotate(45deg);
}

.page-about .timeline__when {
  font-size: 13px;
  letter-spacing: 0.08em;
  color: var(--orange);
}

.page-about .timeline__title {
  margin-top: 7px;
  font-family: var(--ff-display);
  font-weight: 400;
  font-size: clamp(18px, 2.2vw, 23px);
  letter-spacing: 0.05em;
  color: var(--paper);
}

.page-about .timeline__text {
  margin-top: 9px;
  max-width: 62ch;
  font-size: 15.5px;
  line-height: 1.78;
  color: var(--muted);
}

/* ---------- 记录口径 ---------- */

.page-about .std {
  margin-top: 32px;
  border-top: 1px solid var(--line);
}

.page-about .std__row {
  display: grid;
  grid-template-columns: 1fr;
  gap: 10px;
  padding: 22px 0;
  border-bottom: 1px solid var(--line);
  transition: background var(--ease);
}

.page-about .std__row:hover {
  background: linear-gradient(90deg, rgba(52, 242, 206, 0.08), rgba(52, 242, 206, 0) 72%);
}

.page-about .std__key {
  font-family: var(--ff-display);
  font-weight: 400;
  font-size: 20px;
  letter-spacing: 0.12em;
  color: var(--cyan);
}

.page-about .std__body {
  font-size: 15.5px;
  line-height: 1.78;
  color: var(--muted);
}

.page-about .std__body p + p {
  margin-top: 10px;
}

.page-about .std__note {
  font-family: var(--ff-mono);
  font-variant-numeric: tabular-nums;
  font-size: 12.5px;
  letter-spacing: 0.04em;
  color: var(--orange);
}

/* ---------- 校验流程 ---------- */

.page-about .flow {
  margin-top: 36px;
  display: grid;
  grid-template-columns: 1fr;
  gap: 24px;
}

.page-about .flow__node {
  position: relative;
  padding: 28px 0 4px;
  border-top: 1px solid var(--line);
  transition: border-color var(--ease);
}

.page-about .flow__node::before {
  content: "";
  position: absolute;
  top: -5px;
  left: 0;
  width: 9px;
  height: 9px;
  background: var(--ink-900);
  border: 1px solid var(--orange);
  transform: rotate(45deg);
  transition: border-color var(--ease), background var(--ease);
}

.page-about .flow__node:hover {
  border-top-color: var(--cyan);
}

.page-about .flow__node:hover::before {
  border-color: var(--cyan);
  background: var(--cyan);
}

.page-about .flow__time {
  font-size: 22px;
  letter-spacing: 0.02em;
  color: var(--orange);
  line-height: 1.2;
}

.page-about .flow__title {
  margin-top: 10px;
  font-family: var(--ff-display);
  font-weight: 400;
  font-size: 18px;
  letter-spacing: 0.06em;
  color: var(--paper);
}

.page-about .flow__note {
  margin-top: 10px;
  font-size: 14.5px;
  line-height: 1.75;
  color: var(--muted);
}

.page-about .about-flowfig {
  margin-top: 34px;
}

/* ---------- 团队分工 ---------- */

.page-about .crew {
  margin-top: 34px;
  align-items: start;
}

.page-about .crew__media {
  margin-bottom: 26px;
}

.page-about .crew__item {
  display: grid;
  grid-template-columns: 62px minmax(0, 1fr);
  gap: 16px;
  align-items: start;
  padding: 20px 0;
  border-bottom: 1px solid var(--line);
}

.page-about .crew__num {
  font-size: clamp(28px, 3.4vw, 38px);
  line-height: 1;
  color: var(--cyan);
}

.page-about .crew__role {
  font-family: var(--ff-display);
  font-weight: 400;
  font-size: 19px;
  letter-spacing: 0.06em;
  color: var(--paper);
}

.page-about .crew__desc {
  margin-top: 7px;
  font-size: 14.5px;
  line-height: 1.75;
  color: var(--muted);
}

.page-about .crew__total {
  margin-top: 18px;
  font-size: 13px;
  letter-spacing: 0.08em;
  color: var(--muted);
}

.page-about .crew__total .num {
  font-size: 18px;
  color: var(--orange);
}

/* ---------- 备案与联系 ---------- */

.page-about .registry {
  margin-top: 34px;
  align-items: start;
}

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

.page-about .reg-list li {
  padding: 16px 0;
  border-bottom: 1px solid var(--line);
}

.page-about .reg-list li:first-child {
  border-top: 1px solid var(--line);
}

.page-about .reg-key {
  display: block;
  font-size: 12px;
  letter-spacing: 0.16em;
  color: var(--muted);
  margin-bottom: 7px;
}

.page-about .reg-val {
  display: block;
  font-family: var(--ff-mono);
  font-variant-numeric: tabular-nums;
  font-size: 15.5px;
  line-height: 1.6;
  color: var(--paper);
  word-break: break-word;
}

.page-about .registry__note {
  margin-top: 18px;
  max-width: 54ch;
  font-size: 14.5px;
  line-height: 1.78;
  color: var(--muted);
}

.page-about .registry__acts {
  margin-top: 20px;
}

.page-about .registry__side {
  margin-top: 26px;
}

.page-about .reg-panel {
  position: relative;
  background: var(--ink-800);
  border: 1px solid var(--line);
  padding: 24px 22px 26px;
  clip-path: polygon(0 0, 100% 0, 100% calc(100% - 20px), calc(100% - 20px) 100%, 0 100%);
}

.page-about .reg-panel::before {
  content: "";
  position: absolute;
  top: 0;
  left: 0;
  width: 48px;
  height: 2px;
  background: linear-gradient(90deg, var(--cyan), var(--orange));
}

.page-about .reg-panel__key {
  font-size: 12px;
  letter-spacing: 0.16em;
  color: var(--muted);
}

.page-about .reg-panel__list {
  list-style: none;
  margin: 16px 0 0;
  padding: 0;
}

.page-about .reg-panel__list li {
  position: relative;
  padding-left: 16px;
  font-size: 14.5px;
  line-height: 1.72;
  color: var(--paper);
}

.page-about .reg-panel__list li + li {
  margin-top: 10px;
}

.page-about .reg-panel__list li::before {
  content: "";
  position: absolute;
  top: 9px;
  left: 0;
  width: 6px;
  height: 6px;
  border: 1px solid var(--cyan);
  transform: rotate(45deg);
}

.page-about .reg-panel__boundary {
  margin-top: 18px;
  padding-top: 14px;
  border-top: 1px solid var(--line);
  font-size: 13px;
  line-height: 1.7;
  color: var(--orange);
}

/* ---------- 断点 ---------- */

@media (min-width: 640px) {
  .page-about .about-plaque__grid {
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }
}

@media (min-width: 720px) {
  .page-about .std__row {
    grid-template-columns: 148px minmax(0, 1fr);
    gap: 24px;
    align-items: start;
  }

  .page-about .flow {
    grid-template-columns: repeat(3, minmax(0, 1fr));
    gap: 0;
  }

  .page-about .flow__node {
    padding-right: 36px;
  }
}

@media (min-width: 960px) {
  .page-about .about-plaque__grid {
    grid-template-columns: repeat(5, minmax(0, 1fr));
  }

  .page-about .about-body {
    grid-template-columns: var(--rail-w) minmax(0, 1fr);
    gap: 56px;
  }

  .page-about .about-rail {
    position: sticky;
    top: var(--anchor-offset);
    align-self: start;
  }

  .page-about .about-rail__list {
    flex-direction: column;
    flex-wrap: nowrap;
    gap: 0;
  }

  .page-about .about-rail__list a {
    border-bottom: 0;
    border-left: 1px solid var(--line);
    padding: 9px 0 9px 14px;
  }

  .page-about .about-rail__list a:hover,
  .page-about .about-rail__list a:focus-visible {
    border-left-color: var(--cyan);
    border-bottom-color: transparent;
  }

  .page-about .about-rail__list a.is-active {
    background: linear-gradient(90deg, rgba(52, 242, 206, 0.13), rgba(52, 242, 206, 0) 78%);
    border-left-color: var(--cyan);
    border-bottom-color: transparent;
  }

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

  .page-about .crew__media,
  .page-about .registry__side {
    margin-top: 0;
    margin-bottom: 0;
  }
}

@media (min-width: 1180px) {
  .page-about .about-hero__media {
    margin-top: 22px;
  }
}

@media (prefers-reduced-motion: reduce) {
  .page-about .about-rail__list a,
  .page-about .std__row,
  .page-about .flow__node,
  .page-about .flow__node::before,
  .page-about .about-sec__foot a {
    transition: none;
  }
}