.page-about {
  --about-toc: 220px;
  --about-gap: clamp(24px, 4vw, 56px);
  background: var(--ink);
  color: var(--text);
  font-family: var(--font-body);
  font-size: 15px;
  line-height: 1.78;
}

.page-about .about-crumb-row {
  padding-top: clamp(14px, 2.4vw, 22px);
  padding-bottom: clamp(10px, 1.8vw, 16px);
}

.page-about .breadcrumbs__list {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 8px;
  margin: 0;
  padding: 0;
  list-style: none;
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.04em;
}

.page-about .breadcrumbs__link {
  color: var(--mute);
  text-decoration: none;
  border-bottom: 1px solid transparent;
  transition: color 0.16s var(--ease), border-color 0.16s var(--ease);
}

.page-about .breadcrumbs__link:hover,
.page-about .breadcrumbs__link:focus-visible {
  color: var(--mint);
  border-bottom-color: var(--mint);
}

.page-about .breadcrumbs__link[aria-current="page"] {
  color: var(--text);
  border-bottom-color: var(--line);
}

.page-about .breadcrumbs__sep {
  color: var(--line);
}

/* ---------- 首屏 ---------- */

.page-about .about-hero {
  position: relative;
  overflow: hidden;
  border-top: 1px solid var(--line);
  border-bottom: 1px solid var(--line);
  background:
    radial-gradient(120% 90% at 100% 0%, rgba(57, 245, 181, 0.10), transparent 58%),
    radial-gradient(90% 80% at 0% 100%, rgba(255, 138, 61, 0.07), transparent 62%),
    var(--ink-2);
}

.page-about .about-hero::after {
  content: "";
  position: absolute;
  inset: 0;
  pointer-events: none;
  background-image:
    linear-gradient(rgba(30, 91, 68, 0.42) 1px, transparent 1px),
    linear-gradient(90deg, rgba(30, 91, 68, 0.42) 1px, transparent 1px);
  background-size: 72px 72px;
  opacity: 0.5;
  -webkit-mask-image: linear-gradient(122deg, #000 0%, transparent 68%);
  mask-image: linear-gradient(122deg, #000 0%, transparent 68%);
}

.page-about .about-hero__inner {
  position: relative;
  z-index: 1;
  display: grid;
  gap: clamp(26px, 4vw, 48px);
  padding-top: clamp(26px, 4.6vw, 64px);
  padding-bottom: clamp(30px, 5vw, 68px);
}

.page-about .eyebrow {
  margin: 0 0 14px;
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.16em;
  text-transform: uppercase;
  color: var(--orange);
}

.page-about .about-hero__title {
  margin: 0 0 18px;
  font-family: var(--font-head);
  font-weight: 800;
  font-size: clamp(30px, 6.2vw, 68px);
  line-height: 1;
  letter-spacing: -0.01em;
  color: var(--paper);
}

.page-about .about-hero__mark {
  display: inline;
  background: linear-gradient(transparent 64%, rgba(57, 245, 181, 0.32) 64%);
  color: var(--mint);
}

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

.page-about .about-hero__lede {
  margin: 0 0 24px;
  max-width: 60ch;
  font-size: 15px;
  line-height: 1.8;
  color: var(--mute);
}

.page-about .about-hero__facts {
  display: flex;
  flex-wrap: wrap;
  gap: 14px 28px;
  margin: 0;
  padding: 0;
  list-style: none;
}

.page-about .about-hero__fact {
  display: flex;
  flex-direction: column;
  gap: 2px;
  padding-left: 12px;
  border-left: 2px solid var(--line);
}

.page-about .about-hero__fact-num {
  font-family: var(--font-mono);
  font-weight: 700;
  font-size: clamp(24px, 4vw, 32px);
  line-height: 1.1;
  color: var(--mint);
}

.page-about .about-plus,
.page-about .about-unit {
  font-size: 0.56em;
  color: var(--orange);
}

.page-about .about-hero__fact-label {
  font-size: 12px;
  letter-spacing: 0.04em;
  color: var(--mute);
}

.page-about .about-hero__figure {
  position: relative;
  margin: 0;
  border: 1px solid var(--line);
  background: var(--panel);
}

.page-about .about-hero__figure img {
  display: block;
  width: 100%;
  height: auto;
  object-fit: cover;
  filter: saturate(0.9);
}

.page-about .about-hero__cap {
  display: block;
  padding: 8px 10px;
  border-top: 1px solid var(--line);
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: 0.06em;
  color: var(--mute);
}

/* ---------- 正文两栏 ---------- */

.page-about .about-body {
  display: grid;
  gap: var(--about-gap);
  padding-top: clamp(28px, 4.4vw, 60px);
  padding-bottom: clamp(40px, 7vw, 88px);
}

.page-about .about-toc__label {
  margin: 0 0 10px;
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: 0.18em;
  text-transform: uppercase;
  color: var(--orange);
}

.page-about .about-toc__list {
  display: flex;
  gap: 6px;
  margin: 0;
  padding: 0 0 8px;
  list-style: none;
  overflow-x: auto;
  -webkit-overflow-scrolling: touch;
  scrollbar-width: thin;
}

.page-about .about-toc__item {
  flex: 0 0 auto;
}

.page-about .about-toc__link {
  display: flex;
  align-items: baseline;
  gap: 8px;
  padding: 7px 11px;
  border: 1px solid var(--line);
  color: var(--mute);
  font-size: 13px;
  text-decoration: none;
  white-space: nowrap;
  transition: color 0.16s var(--ease), border-color 0.16s var(--ease), background-color 0.16s var(--ease);
}

.page-about .about-toc__num {
  font-family: var(--font-mono);
  font-size: 11px;
  color: var(--orange);
  transition: color 0.16s var(--ease);
}

.page-about .about-toc__link:hover,
.page-about .about-toc__link:focus-visible {
  color: var(--mint);
  border-color: var(--mint);
  background: var(--panel);
}

.page-about .about-toc__link:hover .about-toc__num,
.page-about .about-toc__link:focus-visible .about-toc__num {
  color: var(--mint);
}

/* ---------- 画板 ---------- */

.page-about .about-flow {
  display: flex;
  flex-direction: column;
  gap: clamp(30px, 4.6vw, 56px);
  min-width: 0;
}

.page-about .sheet {
  position: relative;
  padding-top: clamp(18px, 2.6vw, 28px);
  border-top: 1px solid var(--line);
  scroll-margin-top: calc(var(--header-h) + 24px);
  transition: box-shadow 0.2s var(--ease), background-color 0.2s var(--ease);
}

.page-about .sheet:target {
  background: linear-gradient(90deg, rgba(57, 245, 181, 0.07), transparent 62%);
  box-shadow: inset 2px 0 0 var(--mint);
}

.page-about .sheet__head {
  display: flex;
  flex-direction: column;
  gap: 4px;
  margin-bottom: 16px;
}

.page-about .sheet__num {
  display: block;
  font-family: var(--font-mono);
  font-weight: 700;
  font-size: clamp(30px, 4.6vw, 44px);
  line-height: 1;
  letter-spacing: 0.02em;
  color: var(--line);
  transition: color 0.16s var(--ease);
}

.page-about .sheet:hover .sheet__num {
  color: var(--mint);
}

.page-about .sheet__title {
  margin: 0;
  font-family: var(--font-head);
  font-weight: 700;
  font-size: clamp(21px, 3.2vw, 32px);
  line-height: 1.14;
  color: var(--paper);
}

.page-about .sheet p {
  margin: 0 0 14px;
  max-width: 68ch;
}

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

.page-about .sheet__aside {
  margin-top: 16px;
  padding-left: 12px;
  border-left: 2px solid var(--orange);
  font-size: 14px;
  color: var(--mute);
}

.page-about .about-inline-link {
  color: var(--mint);
  text-decoration: none;
  border-bottom: 1px solid var(--line);
  transition: border-color 0.16s var(--ease);
}

.page-about .about-inline-link:hover,
.page-about .about-inline-link:focus-visible {
  border-bottom-color: var(--mint);
}

.page-about .band {
  margin: 18px 0;
  height: 3px;
  border: 0;
}

/* ---------- 时间线 ---------- */

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

.page-about .timeline__axis {
  display: block;
  width: 100%;
  height: 22px;
  margin-bottom: 4px;
  color: var(--line);
}

.page-about .timeline__axis circle {
  fill: var(--mint);
}

.page-about .timeline__axis circle:last-of-type {
  fill: var(--orange);
}

.page-about .tl {
  border-top: 1px solid rgba(30, 91, 68, 0.72);
}

.page-about .tl summary {
  display: flex;
  flex-wrap: wrap;
  align-items: baseline;
  gap: 6px 14px;
  padding: 13px 0;
  cursor: pointer;
  list-style: none;
}

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

.page-about .tl summary::after {
  content: "+";
  margin-left: auto;
  font-family: var(--font-mono);
  font-size: 16px;
  color: var(--mute);
  transition: color 0.16s var(--ease);
}

.page-about .tl[open] summary::after {
  content: "–";
  color: var(--mint);
}

.page-about .tl summary:hover::after,
.page-about .tl summary:focus-visible::after {
  color: var(--mint);
}

.page-about .tl__year {
  flex: 0 0 auto;
  min-width: 74px;
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.02em;
  color: var(--mint);
}

.page-about .tl[open] .tl__year {
  color: var(--orange);
}

.page-about .tl__stage {
  font-family: var(--font-head);
  font-size: 18px;
  letter-spacing: 0.01em;
  color: var(--paper);
}

.page-about .tl__body {
  padding: 0 0 16px 88px;
  font-size: 14px;
  line-height: 1.76;
  color: var(--mute);
}

/* ---------- 团队细线网格 ---------- */

.page-about .crew {
  display: grid;
  gap: 1px;
  margin-top: 20px;
  border: 1px solid var(--line);
  background: var(--line);
}

.page-about .crew__item {
  padding: 16px 18px;
  background: var(--panel);
}

.page-about .crew__meta {
  margin: 0 0 4px;
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: 0.14em;
  color: var(--orange);
}

.page-about .crew__name {
  margin: 0 0 8px;
  font-family: var(--font-head);
  font-size: 19px;
  font-weight: 700;
  color: var(--paper);
}

.page-about .crew__text {
  margin: 0;
  font-size: 13.5px;
  line-height: 1.72;
  color: var(--mute);
}

/* ---------- 资料库 ---------- */

.page-about .about-lib {
  display: grid;
  gap: clamp(18px, 3vw, 28px);
  margin-top: 20px;
  align-items: start;
}

.page-about .about-lib__figure {
  margin: 0;
  border: 1px solid var(--line);
  background: var(--panel-2);
}

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

.page-about .lib-index {
  display: grid;
  gap: 1px;
  margin-top: 22px;
  border: 1px solid var(--line);
  background: var(--line);
}

.page-about .lib-index__item {
  padding: 15px 16px;
  background: var(--ink-2);
}

.page-about .lib-index__key {
  margin: 0 0 6px;
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: 0.14em;
  color: var(--mint);
}

.page-about .lib-index__name {
  margin: 0 0 8px;
  font-family: var(--font-head);
  font-size: 18px;
  font-weight: 700;
  color: var(--paper);
}

.page-about .lib-index__text {
  margin: 0;
  font-size: 13.5px;
  line-height: 1.7;
  color: var(--mute);
}

/* ---------- 合作生态 ---------- */

.page-about .about-eco {
  display: grid;
  gap: clamp(20px, 3.4vw, 34px);
  margin-top: 20px;
  align-items: start;
}

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

.page-about .eco__item {
  padding: 0 0 14px 14px;
  margin-bottom: 14px;
  border-left: 1px solid var(--line);
  transition: border-color 0.16s var(--ease);
}

.page-about .eco__item:hover {
  border-left-color: var(--mint);
}

.page-about .eco__name {
  margin: 0 0 5px;
  font-family: var(--font-head);
  font-size: 17px;
  font-weight: 700;
  color: var(--paper);
}

.page-about .eco__text {
  margin: 0;
  font-size: 13.5px;
  line-height: 1.72;
  color: var(--mute);
}

.page-about .about-eco__figure {
  margin: 0;
  border: 1px solid var(--line);
  background: var(--panel);
}

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

/* ---------- 承诺 ---------- */

.page-about .pledge {
  display: grid;
  gap: 14px;
  margin: 20px 0 0;
  padding: 0;
  list-style: none;
}

.page-about .pledge__item {
  display: grid;
  grid-template-columns: 1fr;
  gap: 4px;
  padding-top: 12px;
  border-top: 1px solid var(--line);
}

.page-about .pledge__key {
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.04em;
  color: var(--mint);
}

.page-about .pledge__val {
  font-size: 14px;
  line-height: 1.74;
  color: var(--text);
}

/* ---------- 下一页入口 ---------- */

.page-about .about-next {
  padding-top: clamp(20px, 3vw, 28px);
  border-top: 1px solid var(--line);
}

.page-about .about-next__title {
  margin: 0 0 14px;
  font-family: var(--font-head);
  font-weight: 700;
  font-size: clamp(19px, 2.6vw, 24px);
  color: var(--paper);
}

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

.page-about .next-card {
  display: flex;
  flex-direction: column;
  gap: 6px;
  padding: 16px 18px;
  background: var(--panel);
  color: var(--text);
  text-decoration: none;
  transition: background-color 0.16s var(--ease), box-shadow 0.16s var(--ease);
}

.page-about .next-card__index {
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: 0.14em;
  color: var(--orange);
}

.page-about .next-card__name {
  font-family: var(--font-head);
  font-size: 17px;
  line-height: 1.3;
  color: var(--paper);
  transition: color 0.16s var(--ease);
}

.page-about .next-card__go {
  margin-top: 4px;
  font-family: var(--font-mono);
  font-size: 12px;
  color: var(--mute);
  transition: color 0.16s var(--ease);
}

.page-about .next-card:hover,
.page-about .next-card:focus-visible {
  background: var(--panel-2);
  box-shadow: inset 0 0 0 1px var(--mint);
}

.page-about .next-card:hover .next-card__name,
.page-about .next-card:focus-visible .next-card__name,
.page-about .next-card:hover .next-card__go,
.page-about .next-card:focus-visible .next-card__go {
  color: var(--mint);
}

/* ---------- 平板及以上 ---------- */

@media (min-width: 640px) {
  .page-about .about-hero__inner {
    grid-template-columns: minmax(0, 1.15fr) minmax(0, 0.85fr);
    align-items: end;
  }

  .page-about .crew {
    grid-template-columns: 1fr 1fr;
  }

  .page-about .pledge {
    grid-template-columns: 1fr 1fr;
    gap: 16px 24px;
  }

  .page-about .pledge__item {
    grid-template-columns: 1fr;
  }

  .page-about .lib-index {
    grid-template-columns: repeat(3, 1fr);
  }

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

@media (min-width: 780px) {
  .page-about .about-lib {
    grid-template-columns: minmax(0, 1.05fr) minmax(0, 0.95fr);
  }

  .page-about .about-eco {
    grid-template-columns: minmax(0, 1fr) minmax(0, 0.95fr);
  }

  .page-about .about-br {
    display: inline;
  }

  .page-about .tl__body {
    padding-left: 88px;
  }
}

@media (min-width: 960px) {
  .page-about .about-body {
    grid-template-columns: var(--about-toc) minmax(0, 1fr);
    align-items: start;
  }

  .page-about .about-toc {
    position: sticky;
    top: calc(var(--header-h) + 24px);
  }

  .page-about .about-toc__list {
    flex-direction: column;
    gap: 2px;
    overflow: visible;
    padding-bottom: 0;
  }

  .page-about .about-toc__item {
    flex: 0 0 auto;
  }

  .page-about .about-toc__link {
    border: 0;
    border-left: 2px solid transparent;
    padding: 8px 10px;
    white-space: normal;
    line-height: 1.5;
  }

  .page-about .about-toc__link:hover,
  .page-about .about-toc__link:focus-visible {
    border-left-color: var(--mint);
    background: transparent;
  }
}

@media (prefers-reduced-motion: reduce) {
  .page-about .about-toc__link,
  .page-about .about-toc__num,
  .page-about .sheet,
  .page-about .sheet__num,
  .page-about .tl summary::after,
  .page-about .next-card,
  .page-about .next-card__name,
  .page-about .next-card__go,
  .page-about .breadcrumbs__link,
  .page-about .eco__item {
    transition: none;
  }
}