.page-about {
  --ab-rail-w: 62px;
  --ab-node: rgba(201, 133, 47, 0.55);
  padding-bottom: 72px;
  color: var(--fog-100);
}

.page-about .breadcrumb {
  margin-top: 20px;
  font-size: var(--fs-small);
  color: var(--mist-300);
}

.page-about .breadcrumb a {
  color: var(--mist-300);
  text-decoration: none;
  border-bottom: 1px solid transparent;
  transition: color var(--dur-fast) var(--ease), border-color var(--dur-fast) var(--ease);
}

.page-about .breadcrumb a:hover,
.page-about .breadcrumb a:focus-visible {
  color: var(--copper-300);
  border-bottom-color: var(--copper-300);
}

/* ---------- 首屏 ---------- */

.page-about .ab-hero {
  position: relative;
  margin-top: 16px;
  padding: 28px 0 8px;
  background: linear-gradient(180deg, rgba(23, 44, 74, 0.82), rgba(11, 22, 38, 0) 82%);
  border-bottom: 1px solid var(--line);
}

.page-about .ab-hero .eyebrow {
  display: inline-block;
  padding-bottom: 14px;
  font-size: 11px;
  letter-spacing: 0.22em;
  color: var(--copper-300);
  border-bottom: 2px solid var(--copper-500);
}

.page-about .ab-hero h1 {
  margin: 20px 0 0;
  font-size: clamp(32px, 7vw, 62px);
  line-height: 1.08;
  letter-spacing: -0.01em;
  font-weight: 900;
  color: var(--fog-100);
}

.page-about .ab-hero__lede {
  margin: 20px 0 0;
  max-width: 40em;
  font-size: var(--fs-body);
  line-height: 1.8;
  color: var(--mist-300);
}

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

.page-about .ab-stats li {
  padding: 16px 14px;
  background: var(--ink-800);
  display: flex;
  flex-direction: column;
  gap: 6px;
}

.page-about .ab-stats__num {
  font-size: 26px;
  line-height: 1;
  letter-spacing: 0.02em;
  color: var(--copper-300);
}

.page-about .ab-stats__label {
  font-size: 12px;
  line-height: 1.6;
  color: var(--mist-300);
}

.page-about .ab-index {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
  margin: 24px 0 0;
  padding: 24px 0 0;
}

.page-about .ab-index a {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 8px 12px;
  font-size: 12px;
  color: var(--fog-100);
  text-decoration: none;
  border: 1px solid var(--line);
  background: rgba(23, 44, 74, 0.6);
  transition: border-color var(--dur-fast) var(--ease), color var(--dur-fast) var(--ease);
}

.page-about .ab-index a .mono {
  font-size: 11px;
  letter-spacing: 0.08em;
  color: var(--copper-300);
}

.page-about .ab-index a:hover,
.page-about .ab-index a:focus-visible {
  border-color: var(--copper-500);
  color: var(--copper-300);
}

/* ---------- 章节骨架 ---------- */

.page-about .ab-sec {
  margin-top: 56px;
  padding-top: 24px;
  border-top: 1px solid var(--line);
}

.page-about .ab-sec__rail {
  display: flex;
  align-items: center;
  gap: 12px;
  margin-bottom: 18px;
}

.page-about .ab-sec__num {
  font-family: var(--font-mono);
  font-size: 13px;
  letter-spacing: 0.1em;
  color: var(--copper-500);
  font-variant-numeric: tabular-nums;
}

.page-about .ab-sec__mark {
  font-size: 11px;
  letter-spacing: 0.3em;
  color: var(--mist-300);
}

.page-about .ab-sec h2 {
  margin: 0;
  font-size: clamp(24px, 4.4vw, 38px);
  line-height: 1.2;
  font-weight: 800;
  color: var(--fog-100);
}

.page-about .ab-sec__lead {
  margin: 14px 0 0;
  max-width: 38em;
  font-size: var(--fs-body);
  line-height: 1.8;
  color: var(--mist-300);
}

/* ---------- 01 三条做法 ---------- */

.page-about .ab-rules {
  list-style: none;
  margin: 28px 0 0;
  padding: 0;
  display: grid;
  gap: 1px;
  background: var(--line);
  border: 1px solid var(--line);
}

.page-about .ab-rules li {
  padding: 22px 18px;
  background: var(--ink-800);
  border-left: 2px solid transparent;
  transition: border-color var(--dur-fast) var(--ease), background var(--dur-fast) var(--ease);
}

.page-about .ab-rules li:hover {
  border-left-color: var(--copper-500);
  background: var(--ink-700);
}

.page-about .ab-rules__num {
  display: block;
  font-size: 12px;
  letter-spacing: 0.16em;
  color: var(--copper-300);
}

.page-about .ab-rules h3 {
  margin: 10px 0 0;
  font-size: 20px;
  line-height: 1.35;
  color: var(--fog-100);
}

.page-about .ab-rules p {
  margin: 10px 0 0;
  font-size: 15px;
  line-height: 1.8;
  color: var(--mist-300);
}

.page-about .ab-link {
  display: inline-block;
  margin-top: 14px;
  font-size: 13px;
  color: var(--copper-300);
  text-decoration: none;
  border-bottom: 1px solid var(--node);
  transition: color var(--dur-fast) var(--ease), border-color var(--dur-fast) var(--ease);
}

.page-about .ab-link:hover,
.page-about .ab-link:focus-visible {
  color: var(--metal-hi);
  border-bottom-color: var(--metal-hi);
}

/* ---------- 图片 ---------- */

.page-about .ab-figure {
  margin: 26px 0 0;
  border: 1px solid var(--line);
  background: var(--ink-900);
  overflow: hidden;
}

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

.page-about .ab-figure .media__caption {
  padding: 10px 14px;
  font-size: 12px;
  line-height: 1.6;
  color: var(--mist-300);
  border-top: 1px solid var(--line);
  background: rgba(16, 32, 58, 0.7);
}

/* ---------- 02 时间轴 ---------- */

.page-about .ab-time {
  list-style: none;
  margin: 30px 0 0;
  padding: 0 0 0 26px;
  position: relative;
}

.page-about .ab-time::before {
  content: "";
  position: absolute;
  left: 6px;
  top: 10px;
  bottom: 14px;
  width: 1px;
  background: var(--line-strong);
}

.page-about .ab-time__item {
  position: relative;
  margin-bottom: 10px;
}

.page-about .ab-time__item::before {
  content: "";
  position: absolute;
  left: -25px;
  top: 18px;
  width: 9px;
  height: 9px;
  background: var(--copper-500);
  box-shadow: 0 0 0 3px rgba(201, 133, 47, 0.16);
}

.page-about .ab-time__node {
  border: 1px solid var(--line);
  background: var(--ink-800);
  transition: border-color var(--dur-fast) var(--ease);
}

.page-about .ab-time__node[open] {
  border-color: var(--node);
}

.page-about .ab-time__node > summary {
  list-style: none;
  display: flex;
  flex-wrap: wrap;
  align-items: baseline;
  gap: 6px 14px;
  padding: 14px 16px;
  cursor: pointer;
  transition: background var(--dur-fast) var(--ease);
}

.page-about .ab-time__node > summary::-webkit-details-marker {
  display: none;
}

.page-about .ab-time__node > summary:hover,
.page-about .ab-time__node > summary:focus-visible {
  background: var(--ink-700);
  outline: 2px solid var(--copper-500);
  outline-offset: -2px;
}

.page-about .ab-time__year {
  font-size: 18px;
  letter-spacing: 0.06em;
  color: var(--copper-300);
}

.page-about .ab-time__title {
  font-size: 15px;
  color: var(--fog-100);
}

.page-about .ab-time__more {
  padding: 0 16px 16px;
  border-top: 1px dashed var(--line);
}

.page-about .ab-time__more p {
  margin: 12px 0 0;
  font-size: 14px;
  line-height: 1.85;
  color: var(--mist-300);
}

/* ---------- 03 团队 ---------- */

.page-about .ab-team {
  list-style: none;
  margin: 28px 0 0;
  padding: 0;
}

.page-about .ab-team li {
  display: grid;
  grid-template-columns: 58px minmax(0, 1fr);
  gap: 14px;
  padding: 18px 0;
  border-top: 1px solid var(--line);
}

.page-about .ab-team li:last-child {
  border-bottom: 1px solid var(--line);
}

.page-about .ab-team__num {
  font-size: 30px;
  line-height: 1;
  letter-spacing: 0.02em;
  color: var(--copper-500);
}

.page-about .ab-team__text h3 {
  margin: 0;
  font-size: 17px;
  line-height: 1.4;
  color: var(--fog-100);
}

.page-about .ab-team__text p {
  margin: 8px 0 0;
  font-size: 14px;
  line-height: 1.85;
  color: var(--mist-300);
}

.page-about .ab-figure--inline {
  max-width: 620px;
}

/* ---------- 04 六步流程 ---------- */

.page-about .ab-flow-wrap {
  margin-top: 28px;
}

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

.page-about .ab-flow__step {
  position: relative;
  padding: 16px 16px 18px;
  border: 1px solid var(--line);
  border-left: 2px solid var(--steel-500);
  background: var(--ink-800);
  transition: border-color var(--dur-fast) var(--ease), background var(--dur-fast) var(--ease), transform var(--dur-fast) var(--ease);
}

.page-about .ab-flow__step:hover,
.page-about .ab-flow__step:focus-within {
  border-color: var(--node);
  border-left-color: var(--copper-500);
  background: var(--ink-700);
  transform: translateY(-2px);
}

.page-about .ab-flow__num {
  display: block;
  font-size: 12px;
  letter-spacing: 0.16em;
  color: var(--copper-300);
}

.page-about .ab-flow__title {
  margin: 8px 0 0;
  font-size: 16px;
  line-height: 1.4;
  color: var(--fog-100);
}

.page-about .ab-flow__role {
  margin: 8px 0 0;
  font-size: 11px;
  letter-spacing: 0.14em;
  color: var(--verify-400);
}

.page-about .ab-flow__out {
  margin: 8px 0 0;
  font-size: 13px;
  line-height: 1.75;
  color: var(--mist-300);
}

.page-about .ab-figure--side {
  margin-top: 18px;
}

/* ---------- 05 条目标准（反色面板） ---------- */

.page-about .ab-sec--paper {
  margin-top: 56px;
  padding: 26px 18px 30px;
  background: var(--paper-050);
  border: 1px solid var(--line-strong);
  border-top: 2px solid var(--copper-500);
}

.page-about .ab-sec--paper .ab-sec__num {
  color: #a86a1c;
}

.page-about .ab-sec--paper .ab-sec__mark {
  color: #5d6b7a;
}

.page-about .ab-sec--paper h2 {
  color: var(--paper-ink);
}

.page-about .ab-sec--paper .ab-sec__lead {
  color: #4a5766;
}

.page-about .ab-spec {
  margin-top: 24px;
  display: grid;
  gap: 12px;
}

.page-about .ab-spec__card {
  border: 1px solid rgba(26, 36, 51, 0.18);
  background: #fffdf8;
  transition: border-color var(--dur-fast) var(--ease), box-shadow var(--dur-fast) var(--ease);
}

.page-about .ab-spec__card:hover {
  border-color: var(--copper-500);
  box-shadow: 0 6px 18px rgba(16, 32, 58, 0.1);
}

.page-about .ab-spec__card details > summary {
  list-style: none;
  padding: 16px;
  cursor: pointer;
}

.page-about .ab-spec__card details > summary::-webkit-details-marker {
  display: none;
}

.page-about .ab-spec__card details > summary:focus-visible {
  outline: 2px solid var(--copper-500);
  outline-offset: -2px;
}

.page-about .ab-spec__idx {
  display: block;
  font-size: 11px;
  letter-spacing: 0.16em;
  color: var(--copper-500);
}

.page-about .ab-spec__title {
  margin: 8px 0 0;
  font-size: 17px;
  line-height: 1.4;
  color: var(--paper-ink);
}

.page-about .ab-spec__hint {
  margin: 8px 0 0;
  font-size: 12px;
  color: #6d7987;
}

.page-about .ab-spec__card details[open] .ab-spec__hint {
  color: var(--copper-500);
}

.page-about .ab-spec__more {
  padding: 0 16px 16px;
  border-top: 1px dashed rgba(26, 36, 51, 0.2);
}

.page-about .ab-spec__more p {
  margin: 12px 0 0;
  font-size: 14px;
  line-height: 1.85;
  color: #37424f;
}

/* ---------- 06 覆盖与联系 ---------- */

.page-about .ab-scope {
  margin-top: 26px;
}

.page-about .ab-scope__title {
  margin: 0 0 14px;
  padding-bottom: 10px;
  font-size: 16px;
  color: var(--fog-100);
  border-bottom: 2px solid var(--copper-500);
}

.page-about .ab-tags {
  list-style: none;
  margin: 0;
  padding: 0;
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
}

.page-about .ab-tags li {
  padding: 6px 11px;
  font-size: 13px;
  color: var(--fog-100);
  border: 1px solid var(--line-strong);
  background: rgba(23, 44, 74, 0.7);
}

.page-about .ab-scope__note {
  margin: 14px 0 0;
  font-size: 13px;
  line-height: 1.8;
  color: var(--mist-300);
}

.page-about .ab-scope__col--aside {
  margin-top: 30px;
  padding: 20px 18px;
  border: 1px solid var(--line);
  border-left: 2px solid var(--copper-500);
  background: var(--ink-800);
}

.page-about .ab-contact {
  margin: 0;
}

.page-about .ab-contact > div {
  display: grid;
  grid-template-columns: 74px minmax(0, 1fr);
  gap: 10px;
  padding: 10px 0;
  border-bottom: 1px dashed var(--line);
}

.page-about .ab-contact > div:last-child {
  border-bottom: 0;
}

.page-about .ab-contact dt {
  font-size: 11px;
  letter-spacing: 0.1em;
  color: var(--mist-300);
}

.page-about .ab-contact dd {
  margin: 0;
  font-size: 14px;
  line-height: 1.6;
  color: var(--fog-100);
  word-break: break-word;
}

.page-about .ab-contact a {
  color: var(--copper-300);
  text-decoration: none;
  border-bottom: 1px solid transparent;
  transition: border-color var(--dur-fast) var(--ease);
}

.page-about .ab-contact a:hover,
.page-about .ab-contact a:focus-visible {
  border-bottom-color: var(--copper-300);
}

.page-about .ab-scope__cta {
  display: inline-block;
  margin-top: 18px;
}

/* ---------- 响应式 ---------- */

@media (min-width: 640px) {
  .page-about .ab-stats {
    grid-template-columns: repeat(4, minmax(0, 1fr));
  }

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

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

@media (min-width: 900px) {
  .page-about {
    padding-bottom: 96px;
  }

  .page-about .breadcrumb {
    margin-top: 28px;
  }

  .page-about .ab-hero {
    margin-top: 20px;
    padding: 44px 0 12px;
  }

  .page-about .ab-hero__lede {
    font-size: 18px;
  }

  .page-about .ab-index {
    margin-top: 30px;
  }

  .page-about .ab-sec {
    display: grid;
    grid-template-columns: var(--ab-rail-w) minmax(0, 1fr);
    column-gap: 24px;
    align-items: start;
    margin-top: 72px;
    padding-top: 32px;
  }

  .page-about .ab-sec__rail {
    flex-direction: column;
    align-items: flex-start;
    gap: 16px;
    margin-bottom: 0;
    align-self: start;
    padding-top: 6px;
  }

  .page-about .ab-sec__mark {
    writing-mode: vertical-rl;
    letter-spacing: 0.32em;
    line-height: 1.4;
  }

  .page-about .ab-rules {
    grid-template-columns: repeat(3, minmax(0, 1fr));
    margin-top: 34px;
  }

  .page-about .ab-rules li {
    padding: 26px 22px 28px;
  }

  .page-about .ab-figure {
    margin-top: 32px;
  }

  .page-about .ab-time {
    margin-top: 36px;
    padding-left: 32px;
  }

  .page-about .ab-time__item::before {
    left: -31px;
    top: 22px;
  }

  .page-about .ab-time__node > summary {
    padding: 16px 22px;
    gap: 6px 22px;
  }

  .page-about .ab-time__year {
    font-size: 22px;
    min-width: 62px;
  }

  .page-about .ab-time__more {
    padding: 0 22px 18px;
  }

  .page-about .ab-team li {
    grid-template-columns: 96px minmax(0, 1fr);
    gap: 24px;
    padding: 24px 0;
  }

  .page-about .ab-team__num {
    font-size: 44px;
  }

  .page-about .ab-flow-wrap {
    display: grid;
    grid-template-columns: minmax(0, 7fr) minmax(0, 5fr);
    gap: 24px;
    align-items: start;
    margin-top: 34px;
  }

  .page-about .ab-flow {
    grid-template-columns: repeat(2, minmax(0, 1fr));
    gap: 12px;
  }

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

  .page-about .ab-sec--paper {
    margin-top: 72px;
    padding: 32px 32px 36px;
  }

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

  .page-about .ab-scope {
    margin-top: 34px;
    align-items: start;
  }

  .page-about .ab-scope__col--aside {
    margin-top: 0;
  }
}

@media (min-width: 1200px) {
  .page-about .ab-flow {
    grid-template-columns: repeat(3, minmax(0, 1fr));
  }
}

@media (prefers-reduced-motion: reduce) {
  .page-about .ab-flow__step:hover,
  .page-about .ab-flow__step:focus-within {
    transform: none;
  }
}

.page-about {
  --node: currentColor;
}