.page-about {
  --about-rail: 214px;
  --about-beat: clamp(44px, 6.5vw, 96px);
  --about-text: rgba(248, 250, 252, .78);
  --about-text-dim: rgba(248, 250, 252, .58);
  --about-hair: rgba(148, 163, 184, .22);
  background: var(--c-indigo);
  color: var(--c-paper);
}

.page-about img {
  max-width: 100%;
  height: auto;
  display: block;
}

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

.page-about .breadcrumb {
  padding-top: clamp(16px, 3vw, 28px);
}

/* ---------- 首屏拼贴 ---------- */
.page-about .about-hero {
  padding-block: clamp(20px, 3.5vw, 40px) clamp(32px, 5vw, 64px);
}

.page-about .about-hero__grid {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 22px;
}

.page-about .eyebrow {
  margin: 0 0 14px;
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: .22em;
  text-transform: uppercase;
  color: var(--c-cyan);
}

.page-about .about-hero__title {
  margin: 0;
  font-family: var(--font-display);
  font-weight: 900;
  font-size: clamp(32px, 6vw, 64px);
  line-height: 1.03;
  letter-spacing: -.01em;
}

.page-about .about-hero__text {
  margin: 18px 0 0;
  max-width: 62ch;
  font-size: clamp(15px, 1.5vw, 17px);
  line-height: 1.8;
  color: var(--about-text);
}

.page-about .about-hero__aside {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 10px;
}

.page-about .hero-stat {
  display: flex;
  flex-direction: column;
  gap: 6px;
  padding: 14px 15px;
  border: 1px solid var(--about-hair);
  border-radius: var(--radius);
  background: var(--surface);
  box-shadow: 4px 4px 0 rgba(2, 6, 23, .5);
  transition: border-color .22s var(--ease), transform .22s var(--ease);
}

.page-about .hero-stat:hover {
  border-color: var(--line-cyan);
  transform: translate(-2px, -2px);
}

.page-about .hero-stat--cyan {
  border-left: 3px solid var(--c-cyan);
}

.page-about .hero-stat--gold {
  border-left: 3px solid var(--c-gold);
  background: linear-gradient(140deg, rgba(255, 180, 84, .14), rgba(30, 41, 59, .62));
}

.page-about .hero-stat--wide {
  grid-column: span 2;
}

.page-about .hero-stat__num {
  font-family: var(--font-mono);
  font-size: clamp(22px, 3vw, 30px);
  font-weight: 700;
  line-height: 1;
  color: var(--c-cyan-soft);
}

.page-about .hero-stat--gold .hero-stat__num {
  color: var(--c-gold-soft);
}

.page-about .hero-stat__label {
  font-size: 12.5px;
  line-height: 1.5;
  color: var(--about-text-dim);
}

.page-about .about-hero__media {
  margin: clamp(24px, 4vw, 44px) 0 0;
}

.page-about .media__frame {
  overflow: hidden;
  border: 1px solid var(--line-cyan);
  border-radius: var(--radius);
  background: var(--surface-deep);
}

.page-about .media__img,
.page-about .media__frame img {
  width: 100%;
  object-fit: cover;
}

.page-about .media__caption {
  margin-top: 10px;
  font-size: 12.5px;
  line-height: 1.6;
  color: var(--about-text-dim);
}

/* ---------- 主体两栏：章节导航 + 长卷 ---------- */
.page-about .about-body {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: clamp(28px, 4vw, 48px);
  padding-bottom: var(--about-beat);
}

.page-about .about-toc {
  padding: 16px 0 4px;
  border-top: 2px solid var(--c-cyan);
}

.page-about .about-toc__title {
  margin: 0 0 12px;
  font-family: var(--font-mono);
  font-size: 11.5px;
  letter-spacing: .2em;
  text-transform: uppercase;
  color: var(--c-mist);
}

.page-about .about-toc__list {
  list-style: none;
  margin: 0;
  padding: 0;
  display: grid;
  gap: 2px;
}

.page-about .about-toc__link {
  display: flex;
  align-items: baseline;
  gap: 10px;
  padding: 8px 12px;
  border-left: 2px solid var(--about-hair);
  font-size: 13.5px;
  color: var(--about-text);
  text-decoration: none;
  transition: color .2s var(--ease), border-color .2s var(--ease), background .2s var(--ease);
}

.page-about .about-toc__link:hover {
  color: var(--c-cyan);
  border-left-color: var(--c-cyan);
  background: rgba(0, 229, 255, .07);
}

.page-about .about-toc__num {
  font-family: var(--font-mono);
  font-size: 11.5px;
  color: var(--c-mist);
}

.page-about .about-toc__note {
  margin: 16px 0 0;
  font-size: 12.5px;
  line-height: 1.7;
  color: var(--about-text-dim);
}

.page-about .about-toc__note a {
  color: var(--c-gold);
  text-decoration: none;
  border-bottom: 1px solid var(--line-gold);
}

.page-about .about-toc__note a:hover {
  color: var(--c-gold-soft);
}

/* ---------- 章节 ---------- */
.page-about .about-chapters {
  display: grid;
  gap: clamp(40px, 6vw, 84px);
  min-width: 0;
}

.page-about .chapter {
  padding-top: 26px;
  border-top: 1px solid var(--about-hair);
  min-width: 0;
  transition: border-color .25s var(--ease);
}

.page-about .chapter:target,
.page-about .chapter:hover {
  border-top-color: var(--line-cyan);
}

.page-about .chapter__head {
  display: grid;
  grid-template-columns: auto minmax(0, 1fr);
  gap: 8px 14px;
  margin-bottom: 22px;
}

.page-about .chapter__num {
  grid-row: 1;
  padding-top: 9px;
  font-family: var(--font-mono);
  font-size: 13px;
  letter-spacing: .14em;
  color: var(--c-violet);
}

.page-about .chapter:target .chapter__num {
  color: var(--c-gold);
}

.page-about .chapter__title {
  grid-column: 2;
  margin: 0;
  font-family: var(--font-display);
  font-weight: 800;
  font-size: clamp(25px, 3.4vw, 40px);
  line-height: 1.12;
}

.page-about .chapter__lead {
  grid-column: 2;
  margin: 4px 0 0;
  max-width: 62ch;
  font-size: clamp(15px, 1.4vw, 16.5px);
  line-height: 1.8;
  color: var(--about-text);
}

.page-about .chapter__note {
  grid-column: 2;
  margin: 2px 0 0;
  font-family: var(--font-mono);
  font-size: 11.5px;
  letter-spacing: .18em;
  color: var(--c-mist);
}

.page-about .chapter__body {
  display: grid;
  gap: 18px;
  min-width: 0;
}

.page-about .chapter__text {
  margin: 0;
  max-width: 68ch;
  font-size: 15px;
  line-height: 1.85;
  color: var(--about-text);
}

.page-about .chapter__actions {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
  padding-top: 6px;
}

/* 三条标准 */
.page-about .principle-list {
  list-style: none;
  margin: 6px 0 0;
  padding: 0;
  display: grid;
  gap: 10px;
}

.page-about .principle {
  display: grid;
  grid-template-columns: 34px minmax(0, 1fr);
  gap: 12px;
  align-items: start;
  padding: 14px 16px;
  border: 1px solid var(--about-hair);
  border-left: 3px solid var(--c-cyan);
  border-radius: var(--radius);
  background: var(--surface);
  transition: border-left-color .2s var(--ease), background .2s var(--ease);
}

.page-about .principle:hover {
  border-left-color: var(--c-gold);
  background: rgba(30, 41, 59, .82);
}

.page-about .principle__idx {
  font-family: var(--font-mono);
  font-size: 13px;
  color: var(--c-cyan-soft);
  padding-top: 2px;
}

.page-about .principle__text {
  font-size: 14.5px;
  line-height: 1.75;
  color: var(--about-text);
}

/* ---------- 时间线 ---------- */
.page-about .timeline-figure {
  margin: 0 0 8px;
}

.page-about .timeline {
  list-style: none;
  margin: 0;
  padding: 0 0 0 26px;
  position: relative;
}

.page-about .timeline::before {
  content: "";
  position: absolute;
  left: 5px;
  top: 8px;
  bottom: 8px;
  width: 2px;
  background: linear-gradient(180deg, var(--c-cyan), var(--c-violet) 55%, var(--c-gold));
  opacity: .75;
}

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

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

.page-about .timeline__item::before {
  content: "";
  position: absolute;
  left: -26px;
  top: 6px;
  width: 12px;
  height: 12px;
  background: var(--c-indigo);
  border: 2px solid var(--c-violet);
  border-radius: 50%;
  transition: border-color .2s var(--ease), transform .2s var(--ease);
}

.page-about .timeline__item:hover::before {
  border-color: var(--c-gold);
  transform: scale(1.18);
}

.page-about .timeline__ver {
  display: inline-block;
  margin-bottom: 8px;
  padding: 3px 9px;
  border: 1px solid var(--line-cyan);
  border-radius: var(--radius);
  font-family: var(--font-mono);
  font-size: 12px;
  font-weight: 700;
  letter-spacing: .08em;
  color: var(--c-cyan-soft);
  background: rgba(0, 229, 255, .07);
}

.page-about .timeline__title {
  margin: 0 0 6px;
  font-family: var(--font-display);
  font-weight: 700;
  font-size: clamp(17px, 2vw, 21px);
  line-height: 1.35;
}

.page-about .timeline__text {
  margin: 0;
  max-width: 62ch;
  font-size: 14.5px;
  line-height: 1.8;
  color: var(--about-text);
}

.page-about .tl-fold {
  margin-top: 10px;
  border: 1px solid var(--about-hair);
  border-radius: var(--radius);
  background: rgba(30, 41, 59, .5);
}

.page-about .tl-fold summary {
  cursor: pointer;
  padding: 10px 14px;
  font-family: var(--font-mono);
  font-size: 12.5px;
  letter-spacing: .06em;
  color: var(--c-cyan-soft);
  list-style: none;
}

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

.page-about .tl-fold summary::after {
  content: " +";
  color: var(--c-gold);
}

.page-about .tl-fold[open] summary::after {
  content: " −";
}

.page-about .tl-fold__body {
  padding: 0 14px 14px;
  border-top: 1px solid var(--about-hair);
}

.page-about .tl-fold__body p {
  margin: 12px 0 0;
  font-size: 14px;
  line-height: 1.8;
  color: var(--about-text);
}

/* ---------- 会员权益 ---------- */
.page-about .rights-grid {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 12px;
}

.page-about .rights-card {
  padding: 18px 18px 20px;
  border: 1px solid var(--about-hair);
  border-radius: var(--radius);
  background: var(--surface);
  box-shadow: 5px 5px 0 rgba(2, 6, 23, .45);
  transition: border-color .22s var(--ease), transform .22s var(--ease);
}

.page-about .rights-card:hover {
  border-color: var(--line-cyan);
  transform: translate(-3px, -3px);
}

.page-about .rights-card--gold {
  border-color: var(--line-gold);
  background: linear-gradient(150deg, rgba(255, 180, 84, .14), rgba(30, 41, 59, .6));
}

.page-about .rights-card--gold:hover {
  border-color: var(--c-gold);
}

.page-about .rights-card__title {
  margin: 0 0 8px;
  font-family: var(--font-display);
  font-weight: 700;
  font-size: 18px;
  line-height: 1.3;
}

.page-about .rights-card--gold .rights-card__title {
  color: var(--c-gold-soft);
}

.page-about .rights-card__text {
  margin: 0;
  font-size: 14px;
  line-height: 1.8;
  color: var(--about-text);
}

/* ---------- 团队 ---------- */
.page-about .team-grid {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 22px;
}

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

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

.page-about .team-item {
  padding: 16px 18px;
  border: 1px solid var(--about-hair);
  border-top: 3px solid var(--c-violet);
  border-radius: var(--radius);
  background: var(--surface-deep);
  transition: border-top-color .22s var(--ease);
}

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

.page-about .team-item__num {
  display: block;
  margin-bottom: 8px;
  font-family: var(--font-mono);
  font-size: 22px;
  font-weight: 700;
  line-height: 1;
  color: var(--c-cyan-soft);
}

.page-about .team-item__title {
  margin: 0 0 6px;
  font-family: var(--font-display);
  font-weight: 700;
  font-size: 17px;
}

.page-about .team-item__text {
  margin: 0;
  font-size: 14px;
  line-height: 1.8;
  color: var(--about-text);
}

/* ---------- 合作与认可 ---------- */
.page-about .honor-list {
  list-style: none;
  margin: 4px 0 0;
  padding: 0;
  display: grid;
  gap: 10px;
}

.page-about .honor {
  display: grid;
  grid-template-columns: 62px minmax(0, 1fr);
  gap: 6px 14px;
  padding: 16px 18px;
  border: 1px solid var(--about-hair);
  border-radius: var(--radius);
  background: linear-gradient(120deg, rgba(168, 85, 247, .1), rgba(30, 41, 59, .55));
  transition: border-color .22s var(--ease);
}

.page-about .honor:hover {
  border-color: var(--line-violet);
}

.page-about .honor__year {
  grid-row: span 2;
  font-family: var(--font-mono);
  font-size: 15px;
  font-weight: 700;
  color: var(--c-violet);
  padding-top: 2px;
}

.page-about .honor__title {
  margin: 0;
  font-family: var(--font-display);
  font-weight: 700;
  font-size: 17px;
  line-height: 1.35;
}

.page-about .honor__text {
  grid-column: 2;
  margin: 0;
  font-size: 14px;
  line-height: 1.75;
  color: var(--about-text);
}

/* ---------- 结尾入口 ---------- */
.page-about .about-cta {
  padding: clamp(24px, 4vw, 40px) clamp(20px, 3.5vw, 36px);
  border: 1px solid var(--line-gold);
  border-radius: var(--radius);
  background: linear-gradient(160deg, rgba(255, 180, 84, .13), rgba(11, 27, 58, .9));
  box-shadow: 8px 8px 0 rgba(2, 6, 23, .55);
}

.page-about .about-cta__title {
  margin: 0;
  font-family: var(--font-display);
  font-weight: 800;
  font-size: clamp(22px, 3vw, 32px);
  line-height: 1.2;
}

.page-about .about-cta__text {
  margin: 12px 0 0;
  max-width: 58ch;
  font-size: 14.5px;
  line-height: 1.8;
  color: var(--about-text);
}

.page-about .about-cta__links {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 10px;
  margin-top: 22px;
}

.page-about .about-cta__link {
  display: grid;
  gap: 6px;
  padding: 14px 16px;
  border: 1px solid var(--line-gold);
  border-radius: var(--radius);
  background: rgba(2, 6, 23, .35);
  text-decoration: none;
  transition: background .22s var(--ease), border-color .22s var(--ease), transform .22s var(--ease);
}

.page-about .about-cta__link:hover {
  background: rgba(255, 180, 84, .12);
  border-color: var(--c-gold);
  transform: translate(-2px, -2px);
}

.page-about .about-cta__link-title {
  font-family: var(--font-display);
  font-weight: 700;
  font-size: 16.5px;
  color: var(--c-gold-soft);
}

.page-about .about-cta__link-text {
  font-size: 13.5px;
  line-height: 1.7;
  color: var(--about-text-dim);
}

/* ---------- 桌面增强 ---------- */
@media (min-width: 720px) {
  .page-about .rights-grid {
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }

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

@media (min-width: 940px) {
  .page-about .about-hero__grid {
    grid-template-columns: repeat(12, minmax(0, 1fr));
    column-gap: 26px;
    row-gap: 18px;
    align-items: end;
  }

  .page-about .about-hero__lead {
    grid-column: 1 / span 7;
  }

  .page-about .about-hero__aside {
    grid-column: 8 / span 5;
    align-self: end;
  }

  .page-about .team-grid {
    grid-template-columns: minmax(0, 5fr) minmax(0, 7fr);
    gap: 28px;
    align-items: start;
  }

  .page-about .chapter__head {
    grid-template-columns: auto minmax(0, 1fr) 1.6em;
  }

  .page-about .chapter__note {
    grid-column: 3;
    grid-row: 1 / span 3;
    writing-mode: vertical-rl;
    justify-self: end;
    letter-spacing: .24em;
    align-self: start;
    padding-top: 8px;
  }
}

@media (min-width: 1060px) {
  .page-about .about-body {
    grid-template-columns: var(--about-rail) minmax(0, 1fr);
    gap: clamp(36px, 4.5vw, 68px);
    align-items: start;
  }

  .page-about .about-toc {
    position: sticky;
    top: calc(var(--header-h) + 28px);
  }

  .page-about .chapter__body {
    padding-left: calc(1.4em + 14px);
  }

  .page-about .chapter__head {
    padding-left: 0;
  }
}