.page-about {
  --about-line: 1px solid var(--ink-500);
  display: block;
  color: var(--silver);
}

/* ---------- 通用小节标题 ---------- */
.page-about .about-sec__index {
  margin: 0 0 6px;
  font-size: 0.8125rem;
  letter-spacing: 0.18em;
  color: var(--cyan);
  text-transform: uppercase;
}
.page-about .about-sec__index--paper {
  color: var(--orange-deep);
}
.page-about .about-sec__title {
  margin: 0;
  font-family: var(--display);
  font-weight: 800;
  font-size: clamp(1.75rem, 4vw, 2.75rem);
  line-height: 1.1;
  letter-spacing: -0.01em;
  color: #fff;
}

/* ---------- 首屏 ---------- */
.page-about .crumbs {
  margin: 0 0 clamp(20px, 4vw, 36px);
  font-family: var(--mono);
  font-size: 0.8125rem;
  letter-spacing: 0.02em;
  color: var(--silver-dim);
}
.page-about .crumbs a {
  color: var(--cyan);
  text-decoration: none;
}
.page-about .crumbs a:hover {
  text-decoration: underline;
}
.page-about .crumbs__sep {
  margin: 0 8px;
  color: var(--ink-500);
}

.page-about .about-intro {
  border-top: 2px solid var(--ink-500);
  padding-top: clamp(20px, 4vw, 34px);
  margin-bottom: clamp(40px, 7vw, 72px);
}
.page-about .about-intro__kicker {
  margin: 0 0 14px;
  font-size: 0.8125rem;
  letter-spacing: 0.16em;
  color: var(--orange);
}
.page-about .about-intro__title {
  margin: 0 0 20px;
  max-width: 20ch;
  font-family: var(--display);
  font-weight: 800;
  font-size: clamp(2rem, 6vw, 3.5rem);
  line-height: 1.06;
  letter-spacing: -0.015em;
  color: #fff;
}
.page-about .about-intro__lede {
  margin: 0 0 28px;
  max-width: 62ch;
  font-size: 1.0625rem;
  line-height: 1.8;
  color: var(--silver);
}
.page-about .about-intro__facts {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 1px;
  margin: 0;
  padding: 0;
  list-style: none;
  background: var(--ink-500);
  border: var(--about-line);
}
.page-about .about-intro__facts li {
  background: var(--ink-900);
  padding: 14px 16px;
  font-family: var(--mono);
  font-size: 0.8125rem;
  color: var(--silver-dim);
}
.page-about .about-intro__num {
  display: block;
  margin-bottom: 4px;
  font-size: 1.5rem;
  font-weight: 600;
  color: var(--orange);
}

/* ---------- 平台提供什么 ---------- */
.page-about .about-offer {
  display: grid;
  gap: 20px;
  padding: clamp(24px, 4vw, 36px) 0 clamp(36px, 6vw, 56px);
  border-bottom: var(--about-line);
}
.page-about .about-offer__head {
  display: flex;
  flex-direction: column;
}
.page-about .about-offer__body {
  max-width: 68ch;
}
.page-about .about-offer__body p {
  margin: 0 0 16px;
  line-height: 1.8;
}
.page-about .about-offer__body p:last-of-type {
  margin-bottom: 24px;
}
.page-about .about-offer__links {
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
}

/* ---------- 谁在使用 ---------- */
.page-about .about-who {
  padding: clamp(36px, 6vw, 56px) 0;
  border-bottom: var(--about-line);
}
.page-about .about-who__head,
.page-about .about-who__head .about-sec__title {
  margin-bottom: 24px;
}
.page-about .about-who__list {
  display: grid;
  gap: 1px;
  background: var(--ink-500);
  border-top: var(--about-line);
  border-bottom: var(--about-line);
}
.page-about .about-scene {
  background: var(--ink-900);
  padding: 20px 18px;
}
.page-about .about-scene__tag {
  margin: 0 0 8px;
  font-size: 0.8125rem;
  letter-spacing: 0.1em;
  color: var(--cyan);
}
.page-about .about-scene__name {
  margin: 0 0 8px;
  font-family: var(--display);
  font-weight: 700;
  font-size: 1.125rem;
  line-height: 1.3;
  color: #fff;
}
.page-about .about-scene p {
  margin: 0;
  font-size: 0.9375rem;
  line-height: 1.75;
  color: var(--silver);
}
.page-about .about-who__foot {
  margin: 20px 0 0;
  font-family: var(--mono);
  font-size: 0.8125rem;
  color: var(--silver-dim);
}

/* ---------- 团队与分工 ---------- */
.page-about .about-team {
  padding: clamp(36px, 6vw, 56px) 0;
  border-bottom: var(--about-line);
}
.page-about .about-team__head {
  margin-bottom: 28px;
}
.page-about .about-team__lede {
  margin: 12px 0 0;
  max-width: 48ch;
  color: var(--silver);
  line-height: 1.75;
}
.page-about .about-team__body {
  display: grid;
  gap: 28px;
}
.page-about .about-team__figure {
  border: 2px solid var(--ink-500);
  box-shadow: var(--hard);
  background: var(--ink-700);
  padding: 8px;
}
.page-about .about-team__roles {
  margin: 0;
  padding: 0;
  list-style: none;
  display: grid;
  gap: 0;
  border-top: var(--about-line);
}
.page-about .about-role {
  display: grid;
  grid-template-columns: auto 1fr;
  gap: 16px;
  align-items: start;
  padding: 18px 0;
  border-bottom: var(--about-line);
}
.page-about .about-role__count {
  font-size: 1.75rem;
  font-weight: 600;
  line-height: 1;
  color: var(--orange);
  min-width: 2.2ch;
}
.page-about .about-role__name {
  margin: 0 0 6px;
  font-family: var(--display);
  font-weight: 700;
  font-size: 1.125rem;
  color: #fff;
}
.page-about .about-role p {
  margin: 0;
  font-size: 0.9375rem;
  line-height: 1.75;
  color: var(--silver);
}

/* ---------- 发展历程：纵向刻度时间轨 ---------- */
.page-about .about-timeline {
  padding: clamp(36px, 6vw, 56px) 0;
  border-bottom: var(--about-line);
}
.page-about .about-timeline__head {
  margin-bottom: 24px;
}
.page-about .about-timeline__lede {
  margin: 12px 0 0;
  max-width: 46ch;
  color: var(--silver);
  line-height: 1.75;
}
.page-about .about-timeline__banner {
  margin: 0 0 32px;
  border: var(--about-line);
  background: var(--ink-700);
}
.page-about .about-track {
  list-style: none;
  margin: 0;
  padding: 0 0 0 26px;
  position: relative;
}
.page-about .about-track::before {
  content: "";
  position: absolute;
  left: 5px;
  top: 6px;
  bottom: 6px;
  width: 1px;
  background: var(--ink-500);
}
.page-about .about-track__item {
  position: relative;
  padding-bottom: 18px;
}
.page-about .about-track__item:last-child {
  padding-bottom: 0;
}
.page-about .about-track__dot {
  position: absolute;
  left: -26px;
  top: 10px;
  width: 11px;
  height: 11px;
  border-radius: 50%;
  background: var(--orange);
  box-shadow: 0 0 0 4px var(--ink-900), 0 0 0 5px var(--ink-500);
}
.page-about .about-stage {
  border: var(--about-line);
  background: var(--ink-700);
}
.page-about .about-stage[open] {
  border-color: var(--ink-500);
  border-left: 3px solid var(--orange);
}
.page-about .about-stage__head {
  display: flex;
  flex-wrap: wrap;
  align-items: baseline;
  gap: 10px;
  padding: 14px 16px;
  cursor: pointer;
  list-style: none;
}
.page-about .about-stage__head::-webkit-details-marker {
  display: none;
}
.page-about .about-stage__tag {
  font-size: 0.8125rem;
  letter-spacing: 0.08em;
  color: var(--cyan);
}
.page-about .about-stage__name {
  font-family: var(--display);
  font-weight: 700;
  font-size: 1.0625rem;
  color: #fff;
}
.page-about .about-stage__body {
  padding: 0 16px 16px;
}
.page-about .about-stage__body p {
  margin: 0;
  font-size: 0.9375rem;
  line-height: 1.8;
  color: var(--silver);
}

/* ---------- 服务覆盖 ---------- */
.page-about .about-cover {
  padding: clamp(36px, 6vw, 56px) 0;
  border-bottom: var(--about-line);
}
.page-about .about-cover__inner {
  display: grid;
  gap: 26px;
}
.page-about .about-cover__text p {
  margin: 14px 0 0;
  max-width: 58ch;
  line-height: 1.8;
  color: var(--silver);
}
.page-about .about-cover__text .about-offer__links {
  margin-top: 24px;
}
.page-about .about-cover__figure {
  margin: 0;
  border: var(--about-line);
  background: var(--ink-700);
}

/* ---------- 维护标准（暖纸区） ---------- */
.page-about .about-standards {
  padding: clamp(40px, 7vw, 72px) 0;
}
.page-about .about-standards .about-sec__title {
  color: var(--ink-900);
}
.page-about .about-standards__lede {
  margin: 14px 0 32px;
  max-width: 52ch;
  line-height: 1.8;
  color: #24384a;
}
.page-about .about-board {
  margin: 0;
  display: grid;
  grid-template-columns: 1fr;
  gap: 1px;
  background: #c9b9a4;
  border: 1px solid #c9b9a4;
}
.page-about .about-board__cell {
  background: var(--paper-deep);
  padding: 20px 18px;
}
.page-about .about-board__label {
  margin: 0 0 12px;
  font-size: 0.8125rem;
  letter-spacing: 0.12em;
  color: var(--orange-deep);
}
.page-about .about-board__num {
  display: inline-block;
  font-family: var(--display);
  font-weight: 800;
  font-size: clamp(2.25rem, 7vw, 3rem);
  line-height: 1;
  letter-spacing: -0.02em;
  color: var(--ink-900);
}
.page-about .about-board__unit {
  display: block;
  margin-top: 8px;
  font-family: var(--mono);
  font-size: 0.8125rem;
  color: #33485b;
}
.page-about .about-board__cell p {
  margin: 12px 0 0;
  font-size: 0.9375rem;
  line-height: 1.75;
  color: #24384a;
}
.page-about .about-standards__note {
  margin-top: 32px;
  padding-top: 24px;
  border-top: 2px solid var(--ink-900);
}
.page-about .about-standards__sub {
  margin: 0 0 10px;
  font-family: var(--display);
  font-weight: 700;
  font-size: 1.25rem;
  color: var(--ink-900);
}
.page-about .about-standards__note p {
  margin: 0 0 14px;
  line-height: 1.8;
  color: #24384a;
}
.page-about .about-standards__link {
  font-family: var(--mono);
  font-size: 0.875rem;
  color: var(--orange-deep);
  text-decoration: underline;
  text-underline-offset: 3px;
}

/* ---------- 为什么留在这里 ---------- */
.page-about .about-why {
  padding: clamp(36px, 6vw, 56px) 0 clamp(48px, 8vw, 80px);
}
.page-about .about-why__head {
  margin-bottom: 24px;
}
.page-about .about-why__list {
  margin: 0;
  padding: 0;
  list-style: none;
  display: grid;
  gap: 1px;
  background: var(--ink-500);
  border-top: var(--about-line);
}
.page-about .about-why__list li {
  background: var(--ink-900);
  padding: 20px 18px;
}
.page-about .about-why__list h3 {
  margin: 0 0 8px;
  font-family: var(--display);
  font-weight: 700;
  font-size: 1.125rem;
  color: var(--orange);
}
.page-about .about-why__list p {
  margin: 0;
  font-size: 0.9375rem;
  line-height: 1.75;
  color: var(--silver);
}
.page-about .about-why__cta {
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
  margin-top: 28px;
}

/* ---------- 响应式 ---------- */
@media (min-width: 700px) {
  .page-about .about-intro__facts {
    grid-template-columns: repeat(4, minmax(0, 1fr));
  }
  .page-about .about-who__list {
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }
  .page-about .about-board {
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }
  .page-about .about-why__list {
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }
}

@media (min-width: 960px) {
  .page-about .about-offer {
    grid-template-columns: minmax(0, 4fr) minmax(0, 8fr);
    gap: 40px;
    align-items: start;
  }
  .page-about .about-team__body {
    grid-template-columns: minmax(0, 5fr) minmax(0, 7fr);
    gap: 40px;
    align-items: start;
  }
  .page-about .about-cover__inner {
    grid-template-columns: minmax(0, 7fr) minmax(0, 5fr);
    gap: 40px;
    align-items: start;
  }
  .page-about .about-board {
    grid-template-columns: repeat(4, minmax(0, 1fr));
  }
  .page-about .about-intro__title {
    max-width: 22ch;
  }
}

@media (prefers-reduced-motion: reduce) {
  .page-about .about-stage__body {
    transition: none;
  }
}