.page-about {
  --about-sticky-top: calc(var(--bar-h) + 20px);
  --hair: 1px dashed rgba(198, 208, 219, 0.3);
}

.page-about [id] {
  scroll-margin-top: calc(var(--bar-h) + 28px);
}

/* ---------- 布局骨架 ---------- */
.page-about .about-layout {
  display: grid;
  grid-template-columns: 1fr;
  gap: clamp(28px, 4vw, 40px);
  padding-block: clamp(16px, 2.5vw, 28px) clamp(56px, 8vw, 104px);
}

.page-about .about-body {
  display: flex;
  flex-direction: column;
  gap: clamp(52px, 7vw, 92px);
  min-width: 0;
}

@media (min-width: 1024px) {
  .page-about .about-layout {
    grid-template-columns: 232px minmax(0, 1fr);
    gap: 56px;
  }
}

/* ---------- 段落索引 ---------- */
.page-about .about-index {
  display: flex;
  flex-direction: column;
  gap: 12px;
  min-width: 0;
}

.page-about .about-index__title {
  margin: 0;
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.16em;
  color: var(--cyan-500);
  text-transform: uppercase;
}

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

.page-about .about-index__list::-webkit-scrollbar {
  display: none;
}

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

.page-about .about-index__link {
  display: flex;
  align-items: center;
  gap: 10px;
  padding: 11px 14px;
  border: var(--frame) solid var(--line-700);
  background: var(--ink-800);
  color: var(--mist-300);
  font-size: 15px;
  font-weight: 600;
  letter-spacing: -0.01em;
  text-decoration: none;
  white-space: nowrap;
  transition: color 0.24s var(--ease), border-color 0.24s var(--ease), box-shadow 0.24s var(--ease);
}

.page-about .about-index__link:hover,
.page-about .about-index__link:focus-visible {
  color: var(--paper-100);
  border-color: var(--cyan-500);
  box-shadow: inset 5px 0 0 var(--cyan-500);
}

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

@media (min-width: 1024px) {
  .page-about .about-index {
    position: sticky;
    top: var(--about-sticky-top);
    align-self: start;
  }

  .page-about .about-index__list {
    flex-direction: column;
    gap: 6px;
    overflow: visible;
    padding: 0;
  }

  .page-about .about-index__link {
    width: 100%;
    font-size: 16px;
    padding: 12px 14px;
  }

  .page-about .about-index__foot {
    display: block;
    margin-top: 8px;
  }
}

/* ---------- 首屏 ---------- */
.page-about .about-hero {
  padding-bottom: clamp(28px, 4vw, 44px);
  border-bottom: var(--frame) solid var(--line-700);
}

.page-about .about-hero__title {
  margin: 14px 0 0;
  font-size: clamp(42px, 8.6vw, 92px);
  font-weight: 300;
  letter-spacing: -0.045em;
  line-height: 0.98;
  color: var(--paper-100);
}

.page-about .about-hero__lede {
  margin-top: 22px;
  max-width: 34em;
}

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

.page-about .about-hero__facts {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 1px;
  margin: 32px 0 0;
  padding: 0;
  list-style: none;
  border: var(--frame) solid var(--line-700);
  background: var(--line-700);
}

.page-about .about-hero__facts > li {
  display: flex;
  flex-direction: column;
  gap: 4px;
  padding: 14px 16px;
  background: var(--ink-800);
}

.page-about .about-hero__fact-num {
  font-size: 20px;
  color: var(--cyan-500);
  letter-spacing: 0.02em;
}

.page-about .about-hero__fact-label {
  font-size: 13px;
  color: var(--mist-300);
}

@media (min-width: 768px) {
  .page-about .about-hero__facts {
    grid-template-columns: repeat(4, minmax(0, 1fr));
  }
}

/* ---------- 章节通用 ---------- */
.page-about .about-section__head {
  display: grid;
  gap: 10px;
  padding-bottom: 20px;
  margin-bottom: 30px;
  border-bottom: var(--frame) solid var(--line-700);
}

.page-about .about-section__head .index-num {
  color: var(--cyan-500);
}

.page-about .about-section__head .section-title {
  margin: 0;
  font-size: clamp(26px, 3.6vw, 40px);
  font-weight: 300;
  letter-spacing: -0.03em;
  line-height: 1.15;
  color: var(--paper-100);
}

.page-about .about-section__lede {
  margin: 0;
  max-width: 40em;
  color: var(--mist-300);
  line-height: 1.75;
}

.page-about .about-section__text {
  margin: 22px 0 0;
  max-width: 40em;
  color: var(--mist-300);
  line-height: 1.75;
}

.page-about .about-section a {
  color: var(--cyan-500);
  text-underline-offset: 3px;
}

.page-about .about-section a:hover {
  color: var(--ember-300);
}

/* ---------- 团队卡片 ---------- */
.page-about .role-grid {
  position: relative;
  display: grid;
  grid-template-columns: 1fr;
  gap: 22px;
}

.page-about .role-card {
  position: relative;
  z-index: 1;
  border: var(--frame) solid var(--line-700);
  background: var(--ink-800);
  box-shadow: var(--shadow-hard);
  transition: transform 0.24s var(--ease), box-shadow 0.24s var(--ease), border-color 0.24s var(--ease);
}

.page-about .role-card:hover {
  transform: translateY(-4px);
  box-shadow: var(--shadow-hard-lg);
  border-color: var(--cyan-500);
}

.page-about .role-card__summary {
  display: flex;
  align-items: baseline;
  gap: 12px;
  padding: 18px 18px 16px;
  cursor: pointer;
  list-style: none;
}

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

.page-about .role-card__num {
  font-size: 13px;
  letter-spacing: 0.16em;
  color: var(--violet);
}

.page-about .role-card__name {
  font-size: 19px;
  font-weight: 700;
  letter-spacing: -0.02em;
  color: var(--paper-100);
}

.page-about .role-card__more {
  margin-left: auto;
  font-size: 12px;
  letter-spacing: 0.08em;
  color: var(--mist-300);
  white-space: nowrap;
}

.page-about .role-card__more::after {
  content: " +";
  font-family: var(--font-mono);
  color: var(--cyan-500);
}

.page-about .role-card[open] .role-card__more::after {
  content: " –";
}

.page-about .role-card__body {
  padding: 16px 18px 20px;
  border-top: var(--hair);
}

.page-about .role-card__desc {
  margin: 0 0 14px;
  color: var(--mist-300);
  line-height: 1.7;
  font-size: 15px;
}

.page-about .role-card__list {
  margin: 0;
  padding: 0;
  list-style: none;
  display: grid;
  gap: 8px;
}

.page-about .role-card__list > li {
  position: relative;
  padding-left: 18px;
  font-size: 14px;
  line-height: 1.6;
  color: var(--paper-100);
}

.page-about .role-card__list > li::before {
  content: "";
  position: absolute;
  left: 0;
  top: 8px;
  width: 8px;
  height: 2px;
  background: var(--cyan-500);
}

@media (min-width: 768px) {
  .page-about .role-grid {
    grid-template-columns: repeat(3, minmax(0, 1fr));
    gap: 28px;
  }

  .page-about .role-grid::before {
    content: "";
    position: absolute;
    left: 0;
    right: 0;
    top: 30px;
    border-top: var(--hair);
    z-index: 0;
  }
}

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

.page-about .timeline__item {
  position: relative;
  padding: 0 0 34px 30px;
  border-left: var(--frame) solid var(--line-700);
}

.page-about .timeline__item:last-child {
  border-left-color: transparent;
  padding-bottom: 0;
}

.page-about .timeline__item::before {
  content: "";
  position: absolute;
  left: -8px;
  top: 6px;
  width: 12px;
  height: 12px;
  border: 2px solid var(--cyan-500);
  border-radius: 50%;
  background: var(--ink-900);
  transition: transform 0.24s var(--ease), background 0.24s var(--ease);
}

.page-about .timeline__item--now::before {
  background: var(--cyan-500);
}

.page-about .timeline__item:hover::before {
  transform: scale(1.3);
  background: var(--cyan-500);
}

.page-about .timeline__stamp {
  margin: 0;
  font-size: 12px;
  letter-spacing: 0.14em;
  color: var(--violet);
}

.page-about .timeline__title {
  margin: 8px 0 8px;
  font-size: 20px;
  font-weight: 600;
  letter-spacing: -0.015em;
  color: var(--paper-100);
}

.page-about .timeline__text {
  margin: 0;
  max-width: 38em;
  color: var(--mist-300);
  line-height: 1.75;
  font-size: 15px;
}

.page-about .timeline__note {
  margin: 10px 0 0;
  font-size: 13px;
  letter-spacing: 0.02em;
  color: var(--mist-300);
  opacity: 0.75;
  transition: color 0.24s var(--ease), opacity 0.24s var(--ease);
}

.page-about .timeline__item:hover .timeline__note,
.page-about .timeline__item:focus-within .timeline__note {
  color: var(--ember-300);
  opacity: 1;
}

/* ---------- 图片 ---------- */
.page-about .about-figure {
  margin: 30px 0 0;
  border: var(--frame) solid var(--line-700);
  background: var(--ink-800);
  box-shadow: var(--shadow-hard);
  overflow: hidden;
}

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

.page-about .about-figure__cap {
  padding: 14px 16px;
  border-top: var(--frame) solid var(--line-700);
  font-size: 13px;
  line-height: 1.7;
  color: var(--mist-300);
}

.page-about .about-figure__cap a {
  color: var(--cyan-500);
  text-underline-offset: 3px;
}

.page-about .about-figure--city {
  margin-top: 0;
}

@media (min-width: 768px) {
  .page-about .about-figure--city {
    display: grid;
    grid-template-columns: minmax(0, 1.4fr) minmax(0, 1fr);
  }

  .page-about .about-figure--city .about-figure__cap {
    border-top: 0;
    border-left: var(--frame) solid var(--line-700);
    display: flex;
    align-items: flex-end;
    font-size: 14px;
  }
}

/* ---------- 服务规模 ---------- */
.page-about .scale-figures {
  display: grid;
  grid-template-columns: 1fr;
  gap: 16px;
}

.page-about .scale-figure {
  padding: 20px 18px;
  border: var(--frame) solid var(--line-700);
  border-left: 6px solid var(--cyan-500);
  background: var(--ink-800);
}

.page-about .scale-figure__num {
  display: block;
  font-size: clamp(30px, 4.6vw, 44px);
  font-weight: 300;
  letter-spacing: -0.03em;
  line-height: 1;
  color: var(--amber-400);
}

.page-about .scale-figure__plus {
  font-size: 0.55em;
  margin-left: 2px;
  color: var(--ember-500);
}

.page-about .scale-figure__label {
  display: block;
  margin-top: 10px;
  font-size: 13px;
  color: var(--mist-300);
}

@media (min-width: 640px) {
  .page-about .scale-figures {
    grid-template-columns: repeat(3, minmax(0, 1fr));
  }
}

.page-about .scale-bars {
  display: grid;
  gap: 18px;
  margin-top: 30px;
}

.page-about .scale-bar-row__head {
  display: flex;
  justify-content: space-between;
  gap: 12px;
  margin-bottom: 8px;
  font-size: 14px;
  color: var(--paper-100);
}

.page-about .scale-bar-row__head .u-mono {
  color: var(--cyan-500);
}

.page-about .scale-bar {
  height: 12px;
  border: var(--frame) solid var(--line-700);
  background: var(--ink-800);
}

.page-about .scale-bar__fill {
  display: block;
  height: 100%;
  background: var(--cyan-500);
}

.page-about .scale-bar__fill--alt {
  background: var(--ember-500);
}

/* ---------- 资料维护表 ---------- */
.page-about .library-table {
  width: 100%;
  min-width: 520px;
}

.page-about .library-table__caption {
  caption-side: top;
  text-align: left;
  padding-bottom: 12px;
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.14em;
  color: var(--cyan-500);
}

.page-about .library-table th,
.page-about .library-table td {
  padding: 14px 16px;
  font-size: 15px;
  border-bottom: 1px solid var(--line-700);
  text-align: left;
}

.page-about .library-table tbody th {
  color: var(--paper-100);
  font-weight: 600;
  white-space: nowrap;
}

.page-about .library-table tbody td {
  color: var(--mist-300);
}

/* ---------- 主张 ---------- */
.page-about .principle-list {
  margin: 0;
  padding: 0;
  list-style: none;
  display: grid;
  gap: 26px;
}

.page-about .principle {
  display: grid;
  grid-template-columns: 44px minmax(0, 1fr);
  gap: 16px;
  padding-bottom: 26px;
  border-bottom: var(--hair);
}

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

.page-about .principle__num {
  font-size: 26px;
  font-weight: 300;
  color: var(--violet);
  line-height: 1;
}

.page-about .principle__title {
  margin: 0 0 8px;
  font-size: 19px;
  font-weight: 600;
  letter-spacing: -0.015em;
  color: var(--paper-100);
}

.page-about .principle__text {
  margin: 0;
  max-width: 38em;
  font-size: 15px;
  line-height: 1.75;
  color: var(--mist-300);
}

/* ---------- 协作与加入 ---------- */
.page-about .about-join {
  padding-top: clamp(20px, 3vw, 32px);
}

.page-about .join-grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: 18px;
}

.page-about .join-card {
  padding: 22px 20px;
  border: var(--frame) solid var(--line-700);
  background: var(--ink-800);
  box-shadow: var(--shadow-hard);
}

.page-about .join-card:first-child {
  border-top: 6px solid var(--cyan-500);
}

.page-about .join-card:last-child {
  border-top: 6px solid var(--ember-500);
}

.page-about .join-card__title {
  margin: 0 0 10px;
  font-size: 19px;
  font-weight: 700;
  letter-spacing: -0.02em;
  color: var(--paper-100);
}

.page-about .join-card__text {
  margin: 0;
  font-size: 15px;
  line-height: 1.75;
  color: var(--mist-300);
}

.page-about .join-card__text a {
  color: var(--cyan-500);
  text-underline-offset: 3px;
}

@media (min-width: 768px) {
  .page-about .join-grid {
    grid-template-columns: repeat(2, minmax(0, 1fr));
    gap: 24px;
  }
}

.page-about .join-prep {
  margin-top: 30px;
  padding: 22px 20px;
  border: var(--frame) solid var(--line-700);
  background: var(--ink-800);
}

.page-about .join-prep__title {
  margin: 0 0 16px;
  font-size: 16px;
  font-weight: 600;
  color: var(--paper-100);
}

.page-about .join-prep__list {
  margin: 0;
  padding: 0;
  list-style: none;
  display: grid;
  gap: 10px;
}

.page-about .join-prep__list > li {
  display: flex;
  align-items: baseline;
  gap: 12px;
  font-size: 15px;
  line-height: 1.6;
  color: var(--mist-300);
}

.page-about .join-prep__idx {
  font-size: 12px;
  letter-spacing: 0.14em;
  color: var(--cyan-500);
}

@media (min-width: 768px) {
  .page-about .join-prep__list {
    grid-template-columns: repeat(2, minmax(0, 1fr));
    gap: 12px 28px;
  }
}

.page-about .join-cta {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 18px;
  margin-top: 32px;
  padding-top: 26px;
  border-top: var(--frame) solid var(--line-700);
}

.page-about .join-cta__text {
  margin: 0;
  font-size: 17px;
  font-weight: 600;
  letter-spacing: -0.01em;
  color: var(--paper-100);
}

@media (prefers-reduced-motion: reduce) {
  .page-about .role-card,
  .page-about .timeline__item::before,
  .page-about .timeline__note,
  .page-about .about-index__link {
    transition: none;
  }

  .page-about .role-card:hover {
    transform: none;
  }

  .page-about .timeline__item:hover::before {
    transform: none;
  }
}