.page-about {
  --about-rail: 200px;
  background: var(--c-deep);
  color: var(--c-paper);
  font-family: var(--f-body);
  font-size: var(--fs-body);
  line-height: 1.72;
  overflow-x: hidden;
}

.page-about .container {
  padding-inline: var(--gutter);
}

/* ---------- 首屏 ---------- */
.page-about .about-hero {
  position: relative;
  padding-block: clamp(20px, 4vw, 44px) clamp(36px, 6vw, 76px);
  background:
    radial-gradient(120% 100% at 88% -10%, rgba(38, 224, 255, 0.18), transparent 62%),
    radial-gradient(90% 80% at 0% 100%, rgba(182, 255, 59, 0.10), transparent 60%),
    var(--c-deep);
  isolation: isolate;
}

.page-about .about-hero::before {
  content: "";
  position: absolute;
  inset: 0;
  z-index: -1;
  background-image:
    repeating-linear-gradient(90deg, rgba(30, 71, 102, 0.35) 0 1px, transparent 1px 96px),
    repeating-linear-gradient(0deg, rgba(30, 71, 102, 0.22) 0 1px, transparent 1px 96px);
  mask-image: linear-gradient(180deg, #000 0%, transparent 78%);
  -webkit-mask-image: linear-gradient(180deg, #000 0%, transparent 78%);
  pointer-events: none;
}

.page-about .breadcrumbs__list {
  display: flex;
  flex-wrap: wrap;
  gap: var(--sp-2);
  list-style: none;
  margin: 0 0 clamp(20px, 4vw, 38px);
  padding: 0;
  font-size: var(--fs-small);
  letter-spacing: 0.06em;
}

.page-about .breadcrumbs__item {
  display: inline-flex;
  align-items: center;
}

.page-about .breadcrumbs__item + .breadcrumbs__item::before {
  content: "/";
  margin-right: var(--sp-2);
  color: var(--c-line);
}

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

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

.page-about .breadcrumbs__current {
  color: var(--c-paper);
}

.page-about .about-hero__grid {
  display: grid;
  gap: clamp(24px, 4vw, 48px);
  align-items: end;
}

.page-about .eyebrow {
  margin: 0 0 var(--sp-3);
  font-family: var(--f-mono);
  font-size: var(--fs-small);
  letter-spacing: 0.22em;
  text-transform: uppercase;
  color: var(--c-cyan);
}

.page-about h1 {
  margin: 0 0 var(--sp-4);
  font-family: var(--f-display);
  font-weight: 800;
  font-size: var(--fs-hero);
  line-height: 1.05;
  letter-spacing: -0.02em;
  color: var(--c-paper);
  max-width: 18ch;
}

.page-about h1::after {
  content: "";
  display: block;
  width: 88px;
  height: 4px;
  margin-top: var(--sp-5);
  background: linear-gradient(90deg, var(--c-cyan), var(--c-lime));
  transform: skewX(-24deg);
}

.page-about .lede {
  margin: 0;
  max-width: 58ch;
  color: var(--c-mist);
  font-size: var(--fs-body);
  line-height: 1.72;
}

.page-about .about-hero__actions {
  display: flex;
  flex-wrap: wrap;
  gap: var(--sp-3);
  margin-top: var(--sp-6);
}

.page-about .about-board {
  background: linear-gradient(160deg, var(--c-navy), #0a2038 78%);
  border: 1px solid var(--c-line);
  border-radius: var(--radius-soft);
  padding: clamp(18px, 3vw, 26px);
  clip-path: polygon(0 0, 100% 0, 100% calc(100% - 26px), calc(100% - 26px) 100%, 0 100%);
}

.page-about .about-board__title {
  margin: 0 0 var(--sp-4);
  font-family: var(--f-mono);
  font-size: var(--fs-small);
  letter-spacing: 0.2em;
  text-transform: uppercase;
  color: var(--c-mist);
}

.page-about .about-board__grid {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: var(--sp-4) var(--sp-3);
}

.page-about .about-board .metric {
  display: flex;
  flex-direction: column;
  gap: 2px;
}

.page-about .about-board .metric__value {
  font-family: var(--f-mono);
  font-weight: 600;
  font-size: clamp(1.6rem, 4vw, 2.2rem);
  line-height: 1.1;
  color: var(--c-paper);
}

.page-about .about-board .metric--lime .metric__value {
  color: var(--c-lime);
}

.page-about .about-board .metric--cyan .metric__value {
  color: var(--c-cyan);
}

.page-about .about-board .metric__label {
  font-size: var(--fs-small);
  color: var(--c-mist);
  letter-spacing: 0.04em;
}

.page-about .about-board__unit {
  font-size: 0.62em;
  margin-left: 2px;
}

.page-about .about-board__note {
  margin: var(--sp-4) 0 0;
  padding-top: var(--sp-3);
  border-top: 1px dashed var(--c-line);
  font-size: var(--fs-small);
  color: var(--c-mist);
}

/* ---------- 档案主体 ---------- */
.page-about .about-archive {
  position: relative;
  padding-block: clamp(32px, 6vw, 72px) clamp(48px, 8vw, 96px);
  background: var(--c-deep);
}

.page-about .about-shell {
  display: grid;
  gap: clamp(24px, 4vw, 48px);
  align-items: start;
}

.page-about .about-rail__title {
  margin: 0 0 var(--sp-3);
  font-family: var(--f-mono);
  font-size: var(--fs-small);
  letter-spacing: 0.2em;
  text-transform: uppercase;
  color: var(--c-mist);
}

.page-about .about-rail__list {
  display: flex;
  gap: var(--sp-2);
  margin: 0;
  padding: 0 0 var(--sp-2);
  list-style: none;
  overflow-x: auto;
  scrollbar-width: thin;
}

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

.page-about .about-rail__link {
  display: inline-flex;
  align-items: baseline;
  gap: var(--sp-2);
  padding: var(--sp-2) var(--sp-3);
  border: 1px solid var(--c-line);
  border-radius: 999px;
  color: var(--c-paper);
  font-size: var(--fs-small);
  text-decoration: none;
  white-space: nowrap;
  transition: border-color var(--speed) var(--ease), color var(--speed) var(--ease), background-color var(--speed) var(--ease);
}

.page-about .about-rail__link:hover,
.page-about .about-rail__link:focus-visible {
  border-color: var(--c-cyan);
  color: var(--c-cyan);
  background: rgba(38, 224, 255, 0.08);
}

.page-about .about-rail__num {
  font-family: var(--f-mono);
  font-size: 0.72em;
  color: var(--c-cyan);
}

.page-about .about-body {
  display: grid;
  gap: clamp(36px, 6vw, 72px);
  min-width: 0;
}

/* ---------- 章节 ---------- */
.page-about .chapter {
  position: relative;
  padding-top: var(--sp-4);
  border-top: 1px solid var(--c-line);
  scroll-margin-top: 24px;
}

.page-about .chapter::before {
  content: "";
  position: absolute;
  top: -1px;
  left: 0;
  width: 72px;
  height: 3px;
  background: var(--c-cyan);
  transform: skewX(-28deg);
}

.page-about .chapter__num {
  margin: 0 0 var(--sp-2);
  font-family: var(--f-mono);
  font-size: var(--fs-small);
  letter-spacing: 0.24em;
  color: var(--c-cyan);
}

.page-about .chapter__title {
  margin: 0 0 var(--sp-4);
  font-family: var(--f-display);
  font-weight: 700;
  font-size: var(--fs-section);
  line-height: 1.15;
  letter-spacing: -0.01em;
  color: var(--c-paper);
  max-width: 22ch;
}

.page-about .chapter__lede {
  margin: 0 0 var(--sp-4);
  font-size: var(--fs-body);
  color: var(--c-paper);
  max-width: 62ch;
}

.page-about .chapter p {
  max-width: 64ch;
  color: var(--c-mist);
}

.page-about .chapter h3 {
  color: var(--c-paper);
}

.page-about .chapter__link {
  color: var(--c-cyan);
  text-decoration: none;
  border-bottom: 1px solid rgba(38, 224, 255, 0.45);
  transition: color var(--speed) var(--ease), border-color var(--speed) var(--ease);
}

.page-about .chapter__link:hover,
.page-about .chapter__link:focus-visible {
  color: var(--c-lime);
  border-bottom-color: var(--c-lime);
}

.page-about .chapter__note {
  margin-top: var(--sp-5);
  padding: var(--sp-4);
  border-left: 3px solid var(--c-lime);
  background: rgba(13, 39, 66, 0.72);
  border-radius: 0 var(--radius-soft) var(--radius-soft) 0;
  font-size: var(--fs-small);
  color: var(--c-mist);
}

/* ---------- 图片 ---------- */
.page-about .about-figure {
  margin: var(--sp-6) 0 var(--sp-5);
  border: 1px solid var(--c-line);
  border-radius: var(--radius-soft);
  overflow: hidden;
  background: var(--c-navy);
}

.page-about .about-figure .media-frame__inner {
  overflow: hidden;
}

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

.page-about .about-figure .media-frame__caption {
  padding: var(--sp-3) var(--sp-4);
  font-size: var(--fs-small);
  color: var(--c-mist);
  border-top: 1px solid var(--c-line);
}

/* ---------- 时间线 ---------- */
.page-about .tl {
  position: relative;
  margin: var(--sp-6) 0 0;
  padding: 0 0 0 30px;
  list-style: none;
}

.page-about .tl::before {
  content: "";
  position: absolute;
  left: 8px;
  top: 8px;
  bottom: 8px;
  width: 2px;
  background: linear-gradient(180deg, var(--c-cyan), var(--c-line) 70%, transparent);
}

.page-about .tl-node {
  position: relative;
  margin-bottom: var(--sp-4);
  padding: var(--sp-4) var(--sp-4) var(--sp-4) var(--sp-5);
  background: var(--c-navy);
  border: 1px solid var(--c-line);
  border-radius: var(--radius-soft);
  transition: transform var(--speed) var(--ease), border-color var(--speed) var(--ease), background-color var(--speed) var(--ease);
}

.page-about .tl-node::before {
  content: "";
  position: absolute;
  left: -26px;
  top: 22px;
  width: 10px;
  height: 10px;
  border: 2px solid var(--c-cyan);
  border-radius: 50%;
  background: var(--c-deep);
}

.page-about .tl-node:hover,
.page-about .tl-node:focus,
.page-about .tl-node:focus-within {
  transform: translateY(-3px);
  border-color: var(--c-cyan);
  background: #102c4a;
}

.page-about .tl-node:hover::before,
.page-about .tl-node:focus::before,
.page-about .tl-node:focus-within::before {
  background: var(--c-lime);
  border-color: var(--c-lime);
}

.page-about .tl-node:focus-visible {
  outline: 2px solid var(--focus);
  outline-offset: 3px;
}

.page-about .tl-node__year {
  margin: 0 0 var(--sp-1);
  font-family: var(--f-mono);
  font-weight: 600;
  font-size: 1.0625rem;
  letter-spacing: 0.08em;
  color: var(--c-cyan);
}

.page-about .tl-node__title {
  margin: 0 0 var(--sp-2);
  font-family: var(--f-display);
  font-weight: 700;
  font-size: clamp(1.15rem, 2.4vw, 1.4rem);
  line-height: 1.3;
}

.page-about .tl-node__text {
  margin: 0;
  font-size: 0.9375rem;
  color: var(--c-mist);
}

.page-about .tl-node__more {
  max-height: 0;
  margin: 0;
  opacity: 0;
  overflow: hidden;
  font-size: var(--fs-small);
  color: var(--c-lime);
  transition: max-height 240ms var(--ease), opacity 240ms var(--ease), margin-top 240ms var(--ease);
}

.page-about .tl-node:hover .tl-node__more,
.page-about .tl-node:focus .tl-node__more,
.page-about .tl-node:focus-within .tl-node__more {
  max-height: 140px;
  margin-top: var(--sp-2);
  opacity: 1;
}

/* ---------- 岗位矩阵 ---------- */
.page-about .role-matrix {
  display: grid;
  grid-template-columns: 1fr;
  gap: var(--sp-3);
  margin-top: var(--sp-5);
}

.page-about .role-card {
  padding: var(--sp-4);
  background: linear-gradient(155deg, rgba(13, 39, 66, 0.94), rgba(7, 26, 47, 0.94));
  border: 1px solid var(--c-line);
  border-radius: var(--radius-soft);
  transition: transform var(--speed) var(--ease), border-color var(--speed) var(--ease);
}

.page-about .role-card:hover {
  transform: translateY(-3px);
  border-color: var(--c-cyan);
}

.page-about .role-card__tag {
  margin: 0 0 var(--sp-3);
}

.page-about .role-card__title {
  margin: 0 0 var(--sp-2);
  font-size: 1.0625rem;
  font-weight: 700;
  line-height: 1.4;
}

.page-about .role-card p {
  margin: 0;
  font-size: 0.9375rem;
  color: var(--c-mist);
  max-width: none;
}

/* ---------- 合作生态 ---------- */
.page-about .eco-map {
  margin-top: var(--sp-5);
  padding: clamp(18px, 3vw, 28px);
  background:
    radial-gradient(80% 120% at 20% 0%, rgba(38, 224, 255, 0.12), transparent 62%),
    var(--c-navy);
  border: 1px solid var(--c-line);
  border-radius: var(--radius-soft);
  clip-path: polygon(0 0, calc(100% - 24px) 0, 100% 24px, 100% 100%, 0 100%);
}

.page-about .eco-map__hub {
  margin: 0 0 var(--sp-4);
  font-family: var(--f-display);
  font-weight: 700;
  font-size: clamp(1.1rem, 2.4vw, 1.35rem);
  letter-spacing: 0.02em;
  color: var(--c-paper);
}

.page-about .eco-map__nodes {
  display: flex;
  flex-wrap: wrap;
  gap: var(--sp-2);
  margin: 0 0 var(--sp-5);
  padding: 0;
  list-style: none;
}

.page-about .eco-node {
  display: inline-flex;
  align-items: center;
  gap: var(--sp-2);
  padding: 6px 12px;
  border: 1px solid var(--c-line);
  border-radius: 999px;
  font-size: var(--fs-small);
  color: var(--c-paper);
  transition: border-color var(--speed) var(--ease), color var(--speed) var(--ease);
}

.page-about .eco-node:hover {
  border-color: var(--c-cyan);
  color: var(--c-cyan);
}

.page-about .eco-node__dot {
  width: 7px;
  height: 7px;
  border-radius: 50%;
  background: var(--c-cyan);
  box-shadow: 0 0 0 3px rgba(38, 224, 255, 0.14);
}

.page-about .eco-map__stats {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: var(--sp-3);
  padding-top: var(--sp-4);
  border-top: 1px dashed var(--c-line);
}

.page-about .eco-map__stats .metric {
  display: flex;
  flex-direction: column;
}

.page-about .eco-map__stats .metric__value {
  font-family: var(--f-mono);
  font-weight: 600;
  font-size: clamp(1.4rem, 4vw, 2rem);
  line-height: 1.1;
  color: var(--c-paper);
}

.page-about .eco-map__stats .metric--cyan .metric__value {
  color: var(--c-cyan);
}

.page-about .eco-map__stats .metric--lime .metric__value {
  color: var(--c-lime);
}

.page-about .eco-map__stats .metric__label {
  font-size: var(--fs-small);
  color: var(--c-mist);
}

/* ---------- 用户章节（纸白区） ---------- */
.page-about .chapter--paper {
  padding: clamp(20px, 4vw, 32px);
  background: var(--c-paper);
  border: 1px solid var(--c-paper);
  border-radius: var(--radius-soft);
  color: var(--c-ink);
}

.page-about .chapter--paper::before {
  background: var(--c-alert);
  top: -1px;
}

.page-about .chapter--paper .chapter__num {
  color: #0a6d84;
}

.page-about .chapter--paper .chapter__title {
  color: var(--c-ink);
}

.page-about .chapter--paper .chapter__lede,
.page-about .chapter--paper p {
  color: #12314b;
}

.page-about .chapter--paper .chapter__link {
  color: #0a5f78;
  border-bottom-color: rgba(10, 95, 120, 0.5);
}

.page-about .chapter--paper .chapter__link:hover,
.page-about .chapter--paper .chapter__link:focus-visible {
  color: #1c7a1f;
  border-bottom-color: #1c7a1f;
}

.page-about .users-strip {
  display: grid;
  grid-template-columns: 1fr;
  gap: var(--sp-3);
  margin-top: var(--sp-5);
  padding-top: var(--sp-4);
  border-top: 1px solid rgba(18, 49, 75, 0.18);
}

.page-about .users-strip__item {
  display: flex;
  flex-direction: column;
  gap: 2px;
}

.page-about .users-strip__num {
  font-family: var(--f-mono);
  font-weight: 600;
  font-size: clamp(1.3rem, 3.6vw, 1.75rem);
  line-height: 1.15;
  color: #0a5f78;
}

.page-about .users-strip__label {
  font-size: var(--fs-small);
  color: #3c5c76;
}

/* ---------- 理由 ---------- */
.page-about .why-grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: var(--sp-3);
  margin-top: var(--sp-5);
}

.page-about .why-card {
  position: relative;
  padding: var(--sp-4) var(--sp-4) var(--sp-4) var(--sp-5);
  border: 1px solid var(--c-line);
  border-left: 3px solid var(--c-cyan);
  border-radius: 0 var(--radius-soft) var(--radius-soft) 0;
  background: rgba(13, 39, 66, 0.6);
  transition: transform var(--speed) var(--ease), border-left-color var(--speed) var(--ease), background-color var(--speed) var(--ease);
}

.page-about .why-card:hover {
  transform: translateY(-3px);
  border-left-color: var(--c-lime);
  background: rgba(16, 44, 74, 0.9);
}

.page-about .why-card__idx {
  margin: 0 0 var(--sp-2);
  font-family: var(--f-mono);
  font-size: var(--fs-small);
  letter-spacing: 0.2em;
  color: var(--c-lime);
}

.page-about .why-card__title {
  margin: 0 0 var(--sp-2);
  font-size: 1.0625rem;
  font-weight: 700;
  line-height: 1.4;
}

.page-about .why-card p {
  margin: 0;
  font-size: 0.9375rem;
  color: var(--c-mist);
  max-width: none;
}

/* ---------- 里程碑 ---------- */
.page-about .mile-list {
  margin: var(--sp-5) 0 0;
  padding: 0;
  list-style: none;
}

.page-about .mile-item {
  display: grid;
  gap: var(--sp-2);
  padding: var(--sp-4) 0;
  border-bottom: 1px solid var(--c-line);
}

.page-about .mile-item:first-child {
  border-top: 1px solid var(--c-line);
}

.page-about .mile-item__year {
  margin: 0;
  font-family: var(--f-mono);
  font-weight: 600;
  font-size: 1.0625rem;
  letter-spacing: 0.08em;
  color: var(--c-alert);
}

.page-about .mile-item__title {
  margin: 0 0 var(--sp-2);
  font-family: var(--f-display);
  font-weight: 700;
  font-size: clamp(1.1rem, 2.4vw, 1.35rem);
  line-height: 1.3;
}

.page-about .mile-item__body p {
  margin: 0;
  font-size: 0.9375rem;
  color: var(--c-mist);
  max-width: 60ch;
}

.page-about .about-cta {
  display: flex;
  flex-direction: column;
  gap: var(--sp-4);
  align-items: flex-start;
  margin-top: var(--sp-6);
  padding: clamp(18px, 3vw, 26px);
  background: linear-gradient(120deg, rgba(38, 224, 255, 0.14), rgba(182, 255, 59, 0.10));
  border: 1px solid var(--c-line);
  border-radius: var(--radius-soft);
}

.page-about .about-cta__text {
  margin: 0;
  max-width: 56ch;
  font-size: 0.9375rem;
  color: var(--c-paper);
}

/* ---------- 焦点反馈 ---------- */
.page-about a:focus-visible,
.page-about .btn:focus-visible {
  outline: 2px solid var(--focus);
  outline-offset: 3px;
}

/* ---------- 响应式 ---------- */
@media (min-width: 620px) {
  .page-about .about-hero__grid {
    grid-template-columns: minmax(0, 1.4fr) minmax(0, 1fr);
  }

  .page-about .role-matrix,
  .page-about .why-grid {
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }

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

  .page-about .about-cta {
    flex-direction: row;
    align-items: center;
    justify-content: space-between;
  }
}

@media (min-width: 900px) {
  .page-about .about-shell {
    grid-template-columns: var(--about-rail) minmax(0, 1fr);
    gap: clamp(28px, 4vw, 56px);
  }

  .page-about .about-rail {
    position: sticky;
    top: 24px;
  }

  .page-about .about-rail__list {
    flex-direction: column;
    gap: 2px;
    overflow: visible;
    padding-bottom: 0;
    border-left: 1px solid var(--c-line);
  }

  .page-about .about-rail__link {
    border: 0;
    border-radius: 0;
    padding: var(--sp-2) var(--sp-3);
    margin-left: -1px;
    border-left: 2px solid transparent;
    white-space: normal;
    color: var(--c-mist);
  }

  .page-about .about-rail__link:hover,
  .page-about .about-rail__link:focus-visible {
    border-left-color: var(--c-lime);
    background: rgba(38, 224, 255, 0.06);
    color: var(--c-paper);
  }

  .page-about .chapter__title {
    max-width: 26ch;
  }

  .page-about .mile-item {
    grid-template-columns: 120px minmax(0, 1fr);
    gap: var(--sp-5);
    align-items: start;
  }
}

@media (min-width: 1140px) {
  .page-about .about-board__grid {
    grid-template-columns: repeat(2, minmax(0, 1fr));
    gap: var(--sp-5) var(--sp-4);
  }

  .page-about .role-matrix {
    grid-template-columns: repeat(4, minmax(0, 1fr));
  }

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

@media (prefers-reduced-motion: reduce) {
  .page-about * {
    transition-duration: 0.01ms !important;
    animation-duration: 0.01ms !important;
  }

  .page-about .tl-node:hover,
  .page-about .role-card:hover,
  .page-about .why-card:hover {
    transform: none;
  }
}