.page-about {
  --about-rail: 236px;
  --about-gap: 56px;
  --about-measure: 42rem;
  display: block;
  padding: 26px 0 88px;
  overflow-wrap: break-word;
}

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

/* ---------- 首屏 ---------- */
.page-about .about-hero {
  display: grid;
  gap: 34px;
  padding: 8px 0 62px;
  border-bottom: 1px solid var(--line);
}

.page-about .about-hero__copy > .eyebrow {
  font-size: 12px;
  letter-spacing: 0.16em;
  color: var(--cyan);
  text-transform: uppercase;
  margin: 0;
}

.page-about h1 {
  font-family: var(--font-head);
  font-weight: 900;
  font-size: clamp(28px, 4.4vw, 50px);
  line-height: 1.24;
  letter-spacing: -0.01em;
  color: var(--fg);
  margin: 14px 0 20px;
}

.page-about .about-hero__lede {
  font-size: 17px;
  line-height: 1.9;
  color: var(--fg-2);
  max-width: 40rem;
  margin: 0;
}

.page-about .about-hero__actions {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
  margin-top: 28px;
}

.page-about .about-stats {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: 14px;
  margin: 34px 0 0;
  padding-top: 22px;
  border-top: 1px dashed var(--line);
}

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

.page-about .about-stats dt {
  font-size: 13px;
  line-height: 1.6;
  color: var(--fg-2);
}

.page-about .about-stats dd {
  font-size: clamp(22px, 3vw, 30px);
  line-height: 1.2;
  color: var(--gold);
  margin: 6px 0 0;
}

.page-about .about-hero__visual {
  position: relative;
  margin: 0;
  border-radius: var(--r-lg);
  overflow: hidden;
  border: 1px solid var(--line);
  background:
    repeating-linear-gradient(90deg, rgba(36, 51, 84, 0.5) 0 1px, transparent 1px 48px),
    repeating-linear-gradient(0deg, rgba(36, 51, 84, 0.5) 0 1px, transparent 1px 48px),
    linear-gradient(160deg, var(--ink-1), var(--ink-0));
}

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

.page-about .about-hero__cap {
  position: absolute;
  left: 16px;
  bottom: 14px;
  font-size: 11px;
  letter-spacing: 0.16em;
  color: var(--cyan);
  background: rgba(7, 11, 20, 0.78);
  border: 1px solid var(--line);
  border-radius: var(--r-pill);
  padding: 5px 12px;
}

/* ---------- 主体两栏 ---------- */
.page-about .about-body {
  display: block;
  padding-top: 58px;
}

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

.page-about .about-article {
  max-width: var(--about-measure);
}

/* ---------- 章节 ---------- */
.page-about .about-section {
  padding-bottom: 62px;
  margin-bottom: 62px;
  border-bottom: 1px solid var(--line);
}

.page-about .about-section--last {
  padding-bottom: 0;
  margin-bottom: 0;
  border-bottom: 0;
}

.page-about .about-section__num {
  display: inline-block;
  font-size: 12px;
  letter-spacing: 0.14em;
  color: var(--gold);
  border: 1px solid var(--line);
  border-radius: var(--r-pill);
  padding: 4px 12px;
  margin: 0;
}

.page-about .about-section__title {
  font-family: var(--font-head);
  font-weight: 700;
  font-size: clamp(21px, 2.6vw, 31px);
  line-height: 1.38;
  letter-spacing: -0.01em;
  color: var(--fg);
  margin: 18px 0 22px;
}

.page-about .about-section p {
  font-size: 16.5px;
  line-height: 1.92;
  color: var(--fg-2);
  margin: 0 0 1.15em;
}

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

/* ---------- 图 ---------- */
.page-about .about-figure {
  margin: 28px 0 32px;
  padding: 0;
  border-radius: var(--r-md);
  overflow: hidden;
  border: 1px solid var(--line);
  background: var(--ink-1);
}

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

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

.page-about .about-figure figcaption {
  font-family: var(--font-mono);
  font-size: 11.5px;
  letter-spacing: 0.14em;
  color: var(--fg-2);
  padding: 10px 16px 12px;
  border-top: 1px solid var(--line);
}

/* ---------- 四类直达标签 ---------- */
.page-about .about-tags {
  display: grid;
  grid-template-columns: 1fr;
  gap: 12px;
  margin-top: 4px;
}

.page-about .about-tag {
  padding: 18px 20px;
  border-radius: var(--r-md);
  border: 1px solid var(--line);
  background: linear-gradient(152deg, var(--ink-2), var(--ink-1) 72%);
  transition: border-color 0.22s var(--ease), transform 0.22s var(--ease);
}

.page-about .about-tag:hover,
.page-about .about-tag:focus-within {
  border-color: var(--cyan);
  transform: translateY(-2px);
}

.page-about .about-tag__name {
  font-family: var(--font-head);
  font-weight: 700;
  font-size: 17px;
  line-height: 1.5;
  color: var(--fg);
  margin: 0 0 8px;
}

.page-about .about-tag__desc {
  font-size: 14.5px;
  line-height: 1.8;
  color: var(--fg-2);
  margin: 0;
}

/* ---------- 版本轴 ---------- */
.page-about .about-axis {
  list-style: none;
  margin: 0;
  padding: 0 0 0 28px;
  position: relative;
}

.page-about .about-axis::before {
  content: "";
  position: absolute;
  left: 4px;
  top: 8px;
  bottom: 8px;
  width: 2px;
  border-radius: 2px;
  background: linear-gradient(180deg, var(--line), var(--cyan) 55%, var(--gold));
}

.page-about .about-axis__item {
  position: relative;
  padding-bottom: 26px;
}

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

.page-about .about-axis__item::before {
  content: "";
  position: absolute;
  left: -28px;
  top: 6px;
  width: 10px;
  height: 10px;
  border-radius: 50%;
  background: var(--ink-0);
  border: 2px solid var(--line);
  box-sizing: content-box;
}

.page-about .about-axis__item[data-state="current"]::before {
  border-color: var(--gold);
  background: var(--gold);
  box-shadow: 0 0 0 5px rgba(255, 196, 87, 0.16);
}

.page-about .about-axis__ver {
  font-size: 15px;
  letter-spacing: 0.05em;
  color: var(--cyan);
  margin: 0 0 6px;
}

.page-about .about-axis__item[data-state="current"] .about-axis__ver {
  color: var(--gold);
}

.page-about .about-axis__note {
  font-size: 15.5px;
  line-height: 1.85;
  color: var(--fg-2);
  margin: 0;
}

/* ---------- 团队 ---------- */
.page-about .about-split {
  display: grid;
  grid-template-columns: 1fr;
  gap: 24px;
  margin-top: 26px;
}

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

.page-about .about-team__item {
  display: grid;
  grid-template-columns: 52px minmax(0, 1fr);
  gap: 14px;
  align-items: start;
  padding: 15px 17px;
  border-radius: var(--r-sm);
  border: 1px solid var(--line);
  background: var(--ink-2);
}

.page-about .about-team__count {
  font-size: 24px;
  line-height: 1.1;
  color: var(--cyan);
}

.page-about .about-team__role {
  font-size: 15.5px;
  font-weight: 600;
  line-height: 1.5;
  color: var(--fg);
  margin: 0 0 5px;
}

.page-about .about-team__desc {
  font-size: 14px !important;
  line-height: 1.78 !important;
  color: var(--fg-2);
  margin: 0 !important;
}

/* ---------- 更新节奏 ---------- */
.page-about .about-cadence {
  display: grid;
  grid-template-columns: 1fr;
  gap: 14px;
  margin: 26px 0 28px;
}

.page-about .about-cadence__card {
  padding: 22px 22px 24px;
  border-radius: var(--r-md);
  border: 1px solid var(--line);
  background: var(--ink-1);
}

.page-about .about-cadence__card--accent {
  background:
    radial-gradient(130% 150% at 100% 0%, rgba(52, 224, 218, 0.12), transparent 62%),
    var(--ink-1);
  border-color: rgba(52, 224, 218, 0.4);
}

.page-about .about-cadence__label {
  font-size: 12px;
  letter-spacing: 0.12em;
  color: var(--orange);
  margin: 0 0 12px;
}

.page-about .about-cadence__name {
  font-family: var(--font-head);
  font-weight: 700;
  font-size: 19px;
  line-height: 1.5;
  color: var(--fg);
  margin: 0 0 10px;
}

.page-about .about-cadence__desc {
  font-size: 14.5px !important;
  line-height: 1.8 !important;
  color: var(--fg-2);
  margin: 0 !important;
}

.page-about .about-coverage {
  font-size: 16px;
  line-height: 1.92;
  color: var(--fg-2);
  margin: 0;
}

/* ---------- 合作 ---------- */
.page-about .about-coop {
  display: grid;
  grid-template-columns: 1fr;
  gap: 12px;
  margin: 4px 0 0;
}

.page-about .about-coop__item {
  border-radius: var(--r-md);
  border: 1px solid var(--line);
  background: linear-gradient(160deg, var(--ink-1), var(--ink-0));
  overflow: hidden;
  transition: border-color 0.22s var(--ease);
}

.page-about .about-coop__item:hover,
.page-about .about-coop__item[open] {
  border-color: var(--cyan);
}

.page-about .about-coop__sum {
  display: flex;
  justify-content: space-between;
  align-items: center;
  gap: 12px;
  padding: 19px 20px;
  cursor: pointer;
  list-style: none;
  font-family: var(--font-head);
  font-weight: 700;
  font-size: 16.5px;
  line-height: 1.5;
  color: var(--fg);
}

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

.page-about .about-coop__mark {
  font-size: 17px;
  line-height: 1;
  color: var(--orange);
  transition: transform 0.24s var(--ease);
}

.page-about .about-coop__item[open] .about-coop__mark {
  transform: rotate(45deg);
}

.page-about .about-coop__body {
  margin: 0 !important;
  padding: 0 20px 20px;
  font-size: 14.5px !important;
  line-height: 1.82 !important;
  color: var(--fg-2);
}

.page-about .about-cta {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  justify-content: space-between;
  gap: 18px;
  margin-top: 34px;
  padding: 26px 26px;
  border-radius: var(--r-lg);
  border: 1px solid var(--line);
  background:
    radial-gradient(120% 150% at 0% 0%, rgba(255, 122, 47, 0.14), transparent 62%),
    var(--ink-1);
}

.page-about .about-cta__text {
  font-family: var(--font-head);
  font-size: 17px;
  line-height: 1.65;
  color: var(--fg);
  margin: 0 !important;
  max-width: 24rem;
}

/* ---------- 平板与桌面 ---------- */
@media (min-width: 640px) {
  .page-about .about-tags {
    grid-template-columns: repeat(2, minmax(0, 1fr));
    gap: 14px;
  }

  .page-about .about-cadence {
    grid-template-columns: repeat(2, minmax(0, 1fr));
    gap: 16px;
  }
}

@media (min-width: 900px) {
  .page-about .about-hero {
    grid-template-columns: 5fr 7fr;
    align-items: center;
    gap: 46px;
  }

  .page-about .about-split {
    grid-template-columns: minmax(0, 1fr) minmax(0, 1.05fr);
    gap: 30px;
    align-items: center;
  }

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

  .page-about .about-coop__body {
    padding: 0 20px 22px;
  }
}

@media (min-width: 1024px) {
  .page-about .about-body {
    display: grid;
    grid-template-columns: var(--about-rail) minmax(0, 1fr);
    gap: var(--about-gap);
    align-items: start;
  }

  .page-about .about-index {
    display: block;
    position: sticky;
    top: 40px;
    padding-left: 18px;
    border-left: 1px solid var(--line);
  }

  .page-about .about-index__title {
    font-size: 11px;
    letter-spacing: 0.18em;
    color: var(--fg-2);
    margin: 0 0 14px;
  }

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

  .page-about .about-index__link {
    display: grid;
    grid-template-columns: 26px minmax(0, 1fr);
    gap: 8px;
    align-items: baseline;
    padding: 8px 0;
    font-size: 14px;
    line-height: 1.55;
    color: var(--fg-2);
    text-decoration: none;
    transition: color 0.2s var(--ease);
  }

  .page-about .about-index__link:hover,
  .page-about .about-index__link:focus-visible {
    color: var(--cyan);
  }

  .page-about .about-index__no {
    font-size: 11.5px;
    letter-spacing: 0.08em;
    color: var(--gold);
    font-family: var(--font-mono);
  }

  .page-about .about-index__scale {
    margin: 22px 0 0;
    padding-top: 14px;
    border-top: 1px dashed var(--line);
    font-size: 11.5px;
    letter-spacing: 0.08em;
    color: var(--fg-2);
  }
}

@media (min-width: 1280px) {
  .page-about .about-hero {
    gap: 60px;
  }

  .page-about .about-section {
    padding-bottom: 68px;
    margin-bottom: 68px;
  }
}

/* 章节悬停时的索引编号提示 */
@media (hover: hover) and (min-width: 1024px) {
  .page-about .about-section {
    position: relative;
  }

  .page-about .about-section::after {
    content: "";
    position: absolute;
    left: -1px;
    top: 0;
    bottom: 62px;
    width: 2px;
    background: linear-gradient(180deg, var(--cyan), transparent);
    opacity: 0;
    transition: opacity 0.24s var(--ease);
    pointer-events: none;
  }

  .page-about .about-section:hover::after {
    opacity: 1;
  }
}

@media (prefers-reduced-motion: reduce) {
  .page-about .about-tag,
  .page-about .about-coop__item,
  .page-about .about-coop__mark,
  .page-about .about-index__link,
  .page-about .about-section::after {
    transition: none;
  }
}