.page-about {
  background: var(--bg);
  color: var(--text);
  font-family: var(--font-body);
  overflow-x: hidden;
}

/* ---------- 首屏 ---------- */
.page-about .about-hero {
  position: relative;
  isolation: isolate;
  padding-top: 32px;
  padding-bottom: 48px;
  border-bottom: 1px solid var(--line);
  overflow: hidden;
}

.page-about .about-hero::before {
  content: "";
  position: absolute;
  inset: -1px;
  z-index: 0;
  background-image:
    linear-gradient(rgba(36, 48, 74, .72) 1px, transparent 1px),
    linear-gradient(90deg, rgba(36, 48, 74, .72) 1px, transparent 1px);
  background-size: 76px 76px;
  -webkit-mask-image: radial-gradient(130% 95% at 76% 8%, #000 0%, transparent 70%);
  mask-image: radial-gradient(130% 95% at 76% 8%, #000 0%, transparent 70%);
  pointer-events: none;
}

.page-about .about-hero::after {
  content: "";
  position: absolute;
  top: -240px;
  right: -170px;
  z-index: 0;
  width: 540px;
  height: 540px;
  border-radius: 50%;
  background: radial-gradient(circle, rgba(124, 77, 255, .42) 0%, rgba(124, 77, 255, 0) 66%);
  pointer-events: none;
}

.page-about .about-hero__grid {
  position: relative;
  z-index: 1;
  display: grid;
  gap: 32px;
}

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

.page-about .about-hero__title {
  margin: 14px 0 0;
  font-family: var(--font-display);
  font-size: clamp(1.85rem, 6.2vw, 3rem);
  line-height: 1.14;
  letter-spacing: .01em;
  color: var(--text);
}

.page-about .about-hero__lede {
  margin: 18px 0 0;
  max-width: 40em;
  font-size: 1rem;
  line-height: 1.85;
  color: var(--muted);
}

.page-about .about-hero__quick {
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
  margin-top: 26px;
}

.page-about .about-hero__media {
  position: relative;
  margin: 0;
}

.page-about .about-hero__media::after {
  content: "";
  position: absolute;
  top: -12px;
  right: -12px;
  width: 92px;
  height: 92px;
  border-top: 2px solid var(--gold);
  border-right: 2px solid var(--gold);
  border-top-right-radius: var(--radius-md);
  opacity: .8;
  pointer-events: none;
}

.page-about .about-hero__media img {
  display: block;
  width: 100%;
  height: auto;
  object-fit: cover;
  border-radius: var(--radius-lg);
}

/* ---------- 索引 + 正文 双栏 ---------- */
.page-about .about-body {
  display: grid;
  gap: 40px;
  padding-top: 52px;
  padding-bottom: 72px;
}

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

.page-about .about-index__head {
  margin: 0 0 14px;
  font-family: var(--font-mono);
  font-size: .78rem;
  letter-spacing: .16em;
  text-transform: uppercase;
  color: var(--gold);
}

.page-about .about-index__list {
  list-style: none;
  margin: 0;
  padding: 0;
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
}

.page-about .about-index__link {
  display: inline-flex;
  align-items: center;
  gap: 10px;
  padding: 9px 15px;
  border: 1px solid var(--line);
  border-radius: var(--pill);
  color: var(--muted);
  font-size: .875rem;
  line-height: 1.3;
  text-decoration: none;
  transition: color var(--dur) var(--ease), border-color var(--dur) var(--ease), background-color var(--dur) var(--ease);
}

.page-about .about-index__link:hover,
.page-about .about-index__link:focus-visible {
  color: var(--text);
  border-color: var(--violet);
  background: rgba(124, 77, 255, .14);
}

.page-about .about-index__no {
  font-family: var(--font-mono);
  font-size: .72rem;
  letter-spacing: .04em;
  color: var(--gold);
}

.page-about .about-index__foot {
  margin: 22px 0 0;
  padding-top: 16px;
  border-top: 1px solid var(--line);
  font-size: .8125rem;
  line-height: 1.8;
  color: var(--muted);
}

.page-about .about-index__jump {
  color: var(--violet-soft);
  text-decoration: none;
  border-bottom: 1px solid rgba(179, 157, 255, .4);
}

.page-about .about-index__jump:hover,
.page-about .about-index__jump:focus-visible {
  color: var(--text);
  border-bottom-color: var(--gold);
}

/* ---------- 章节 ---------- */
.page-about .about-content {
  min-width: 0;
}

.page-about .about-sec {
  scroll-margin-top: 96px;
  padding-bottom: 54px;
  border-bottom: 1px dashed var(--line);
}

.page-about .about-sec + .about-sec {
  padding-top: 54px;
}

.page-about .about-sec:last-of-type {
  border-bottom: 0;
  padding-bottom: 0;
}

.page-about .about-sec__head {
  display: grid;
  grid-template-columns: auto minmax(0, 1fr);
  gap: 14px;
  align-items: baseline;
  margin-bottom: 20px;
}

.page-about .about-sec__no {
  font-family: var(--font-mono);
  font-size: clamp(1.6rem, 5.4vw, 2.35rem);
  font-weight: 600;
  line-height: 1;
  letter-spacing: -.02em;
  color: var(--gold);
  text-shadow: 0 0 26px rgba(230, 184, 76, .35);
}

.page-about .about-sec__title {
  margin: 0;
  font-family: var(--font-display);
  font-size: clamp(1.3rem, 3.6vw, 1.85rem);
  line-height: 1.3;
  letter-spacing: .01em;
  color: var(--text);
}

.page-about .about-sec__prose p {
  margin: 0 0 14px;
  font-size: 1rem;
  line-height: 1.85;
  color: var(--muted);
}

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

.page-about .about-sec__media {
  margin: 26px 0 0;
}

.page-about .about-sec__media img {
  display: block;
  width: 100%;
  height: auto;
  object-fit: cover;
  border-radius: var(--radius-md);
  border: 1px solid var(--line);
}

/* ---------- 旁注 ---------- */
.page-about .about-note {
  margin: 24px 0 0;
  padding: 14px 18px;
  border-left: 2px solid var(--gold);
  border-radius: 0 var(--radius-sm) var(--radius-sm) 0;
  background: rgba(230, 184, 76, .07);
  font-size: .875rem;
  line-height: 1.8;
  color: var(--muted);
}

.page-about .about-note--violet {
  border-left-color: var(--violet);
  background: rgba(124, 77, 255, .1);
}

.page-about .about-note--mint {
  border-left-color: var(--mint);
  background: rgba(53, 208, 186, .08);
}

.page-about .about-note__link {
  color: var(--violet-soft);
  text-decoration: none;
  border-bottom: 1px solid rgba(179, 157, 255, .45);
}

.page-about .about-note__link:hover,
.page-about .about-note__link:focus-visible {
  color: var(--text);
  border-bottom-color: var(--gold);
}

/* ---------- 分类分组 ---------- */
.page-about .about-cats {
  display: grid;
  gap: 14px;
  margin-top: 26px;
}

.page-about .about-cats__group {
  padding: 18px 18px 20px;
  border: 1px solid var(--line);
  border-radius: var(--radius-md);
  background: var(--panel);
}

.page-about .about-cats__group:nth-child(1) {
  border-top: 2px solid var(--violet);
}

.page-about .about-cats__group:nth-child(2) {
  border-top: 2px solid var(--gold);
}

.page-about .about-cats__group:nth-child(3) {
  border-top: 2px solid var(--mint);
}

.page-about .about-cats__title {
  margin: 0;
  font-family: var(--font-display);
  font-size: 1.0625rem;
  letter-spacing: .06em;
  color: var(--text);
}

.page-about .about-cats__list {
  list-style: none;
  margin: 14px 0 0;
  padding: 0;
  display: grid;
  gap: 9px;
}

.page-about .about-cats__item {
  display: flex;
  align-items: baseline;
  gap: 10px;
  font-size: .9375rem;
  line-height: 1.5;
  color: var(--muted);
}

.page-about .about-cats__no {
  flex: 0 0 auto;
  font-family: var(--font-mono);
  font-size: .72rem;
  color: var(--line);
  filter: brightness(1.9);
}

/* ---------- 团队标签页 ---------- */
.page-about .about-tabs {
  margin-top: 26px;
}

.page-about .tabs__list {
  display: flex;
  gap: 8px;
  overflow-x: auto;
  padding-bottom: 6px;
  -webkit-overflow-scrolling: touch;
}

.page-about .tab {
  flex: 0 0 auto;
  padding: 10px 20px;
  border: 1px solid var(--line);
  border-radius: var(--pill);
  background: transparent;
  color: var(--muted);
  font-family: var(--font-body);
  font-size: .9rem;
  line-height: 1.2;
  cursor: pointer;
  transition: color var(--dur) var(--ease), border-color var(--dur) var(--ease), background-color var(--dur) var(--ease);
}

.page-about .tab:hover,
.page-about .tab:focus-visible {
  color: var(--text);
  border-color: var(--violet-soft);
}

.page-about .tab[aria-selected="true"] {
  color: #fff;
  border-color: transparent;
  background: linear-gradient(135deg, var(--violet-deep), var(--violet));
  box-shadow: 0 10px 26px rgba(124, 77, 255, .3);
}

.page-about .tabs__panel {
  margin-top: 16px;
  padding: 22px;
  border: 1px solid var(--line);
  border-radius: var(--radius-md);
  background: linear-gradient(160deg, rgba(26, 16, 51, .92), var(--panel));
  font-size: .9375rem;
  line-height: 1.85;
  color: var(--muted);
}

.page-about .tabs__panel p {
  margin: 0;
}

.page-about .tabs__panel[hidden] {
  display: none;
}

/* ---------- 时间线 ---------- */
.page-about .about-timeline {
  list-style: none;
  margin: 28px 0 0;
  padding: 0;
  position: relative;
}

.page-about .about-timeline::before {
  content: "";
  position: absolute;
  top: 8px;
  bottom: 8px;
  left: 9px;
  width: 1px;
  background: linear-gradient(180deg, var(--violet) 0%, var(--gold) 55%, var(--mint) 100%);
  opacity: .75;
}

.page-about .about-timeline__item {
  position: relative;
  padding-left: 38px;
  padding-bottom: 26px;
}

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

.page-about .about-timeline__item::before {
  content: "";
  position: absolute;
  top: 6px;
  left: 3px;
  width: 13px;
  height: 13px;
  border-radius: 50%;
  background: var(--bg);
  border: 2px solid var(--gold);
  box-shadow: 0 0 0 4px rgba(230, 184, 76, .12);
}

.page-about .about-timeline__year {
  display: inline-block;
  margin-bottom: 6px;
  font-family: var(--font-mono);
  font-size: .8rem;
  letter-spacing: .08em;
  color: var(--gold-soft);
}

.page-about .about-timeline__title {
  margin: 0 0 6px;
  font-size: 1.0625rem;
  line-height: 1.45;
  font-weight: 600;
  color: var(--text);
}

.page-about .about-timeline__detail {
  margin: 0;
  font-size: .9375rem;
  line-height: 1.8;
  color: var(--muted);
}

.page-about .about-timeline__item:focus {
  outline: none;
}

/* ---------- 合作生态 ---------- */
.page-about .about-partners {
  display: grid;
  gap: 14px;
  margin-top: 26px;
}

.page-about .about-partners__card {
  padding: 20px;
  border: 1px solid var(--line);
  border-radius: var(--radius-md);
  background: linear-gradient(165deg, rgba(26, 16, 51, .9), var(--panel));
}

.page-about .about-partners__title {
  margin: 0 0 10px;
  font-family: var(--font-display);
  font-size: 1.125rem;
  letter-spacing: .05em;
  color: var(--violet-soft);
}

.page-about .about-partners__body {
  margin: 0;
  font-size: .9375rem;
  line-height: 1.8;
  color: var(--muted);
}

/* ---------- 下一步 ---------- */
.page-about .about-cta {
  margin-top: 58px;
  padding: 30px 22px 32px;
  border: 1px solid var(--line);
  border-radius: var(--radius-lg);
  background:
    radial-gradient(120% 140% at 10% 0%, rgba(124, 77, 255, .3) 0%, rgba(124, 77, 255, 0) 62%),
    var(--panel);
  box-shadow: var(--shadow);
}

.page-about .about-cta__title {
  margin: 0;
  font-family: var(--font-display);
  font-size: clamp(1.25rem, 3.4vw, 1.7rem);
  line-height: 1.3;
  color: var(--text);
}

.page-about .about-cta__body {
  margin: 14px 0 0;
  max-width: 46em;
  font-size: .9375rem;
  line-height: 1.85;
  color: var(--muted);
}

.page-about .about-cta__links {
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
  margin-top: 22px;
}

/* ---------- 中等屏幕 ---------- */
@media (min-width: 700px) {
  .page-about .about-cats {
    grid-template-columns: repeat(3, minmax(0, 1fr));
    gap: 16px;
  }

  .page-about .about-partners {
    grid-template-columns: repeat(3, minmax(0, 1fr));
    gap: 16px;
  }

  .page-about .about-cta {
    padding: 38px 34px 40px;
  }
}

/* ---------- 桌面：左目录 + 右正文 ---------- */
@media (min-width: 900px) {
  .page-about .about-hero {
    padding-top: 44px;
    padding-bottom: 64px;
  }

  .page-about .about-hero__grid {
    grid-template-columns: minmax(0, 1.04fr) minmax(0, .96fr);
    gap: 52px;
    align-items: center;
  }

  .page-about .about-hero__media {
    transform: translateY(14px);
  }
}

@media (min-width: 1024px) {
  .page-about .about-body {
    grid-template-columns: 246px minmax(0, 1fr);
    gap: 62px;
    padding-top: 72px;
    padding-bottom: 96px;
  }

  .page-about .about-index {
    position: sticky;
    top: 92px;
    align-self: start;
    padding-left: 20px;
    border-left: 1px solid var(--line);
  }

  .page-about .about-index__list {
    display: block;
  }

  .page-about .about-index__list li + li {
    margin-top: 4px;
  }

  .page-about .about-index__link {
    width: 100%;
    border-color: transparent;
    border-radius: var(--radius-sm);
    padding: 9px 12px;
  }

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

  .page-about .about-timeline__detail {
    max-height: 0;
    opacity: 0;
    overflow: hidden;
    transition: max-height 220ms var(--ease), opacity 220ms var(--ease);
  }

  .page-about .about-timeline__item:hover .about-timeline__detail,
  .page-about .about-timeline__item:focus-within .about-timeline__detail,
  .page-about .about-timeline__item:focus .about-timeline__detail {
    max-height: 12rem;
    opacity: 1;
  }

  .page-about .about-timeline__item:focus {
    outline: 1px dashed var(--violet-soft);
    outline-offset: 6px;
    border-radius: var(--radius-sm);
  }
}

@media (prefers-reduced-motion: reduce) {
  .page-about .about-index__link,
  .page-about .tab,
  .page-about .about-timeline__detail,
  .page-about .about-note__link,
  .page-about .about-index__jump {
    transition: opacity 160ms linear;
  }

  .page-about .about-hero__media {
    transform: none;
  }
}