.page-about {
  padding-bottom: clamp(40px, 6vw, 72px);
}

.page-about .crumbs {
  display: flex;
  align-items: center;
  gap: 8px;
  padding: clamp(16px, 2.4vw, 24px) 0 0;
  font-size: 13px;
  color: var(--c-stone);
  font-family: var(--font-mono);
}
.page-about .crumbs a {
  color: var(--c-lake);
  text-decoration: none;
  border-bottom: 1px solid transparent;
  transition: border-color .2s var(--ease);
}
.page-about .crumbs a:hover {
  border-bottom-color: var(--c-lake);
}

/* ---------- 首屏 ---------- */
.page-about .ab-hero {
  padding: clamp(20px, 3.4vw, 36px) 0 clamp(18px, 2.6vw, 26px);
}
.page-about .ab-hero .eyebrow {
  margin: 0 0 10px;
  font-family: var(--font-display);
  font-size: 13px;
  letter-spacing: .1em;
  color: var(--c-gold);
}
.page-about .ab-hero h1 {
  margin: 0 0 16px;
  font-family: var(--font-head);
  font-weight: 800;
  font-size: clamp(28px, 4vw, 44px);
  letter-spacing: .04em;
  line-height: 1.28;
  color: var(--c-mist);
  max-width: 20ch;
}
.page-about .ab-hero .lede {
  margin: 0 0 20px;
  font-size: 16px;
  line-height: 1.85;
  color: var(--c-mist);
  max-width: 40ch;
}

.page-about .hero-chips {
  list-style: none;
  margin: 0 0 24px;
  padding: 0;
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
}
.page-about .hero-chips li {
  display: inline-flex;
  align-items: center;
  padding: 5px 12px;
  border: 1px solid var(--line);
  border-radius: 999px;
  font-size: 12px;
  color: var(--c-lake);
  background: rgba(47, 182, 196, .06);
}
.page-about .hero-chips li:nth-child(2) {
  color: var(--c-gold);
  border-color: rgba(232, 178, 76, .35);
  background: rgba(232, 178, 76, .07);
}
.page-about .hero-chips li:nth-child(4) {
  color: var(--c-volt);
  border-color: rgba(111, 227, 210, .3);
  background: rgba(111, 227, 210, .06);
}

.page-about .ab-banner {
  position: relative;
  border: 1px solid var(--line);
  border-radius: var(--r);
  overflow: hidden;
  background: var(--c-indigo);
  box-shadow: var(--shadow-card);
}
.page-about .ab-banner img {
  display: block;
  width: 100%;
  height: auto;
  aspect-ratio: 3 / 1;
  object-fit: cover;
}
.page-about .ab-banner::after {
  content: "";
  position: absolute;
  inset: 0;
  background: linear-gradient(180deg, rgba(11, 26, 46, 0) 46%, rgba(6, 14, 24, .78) 100%);
  pointer-events: none;
}

/* ---------- 章节分隔刻度 ---------- */
.page-about .ab-rule {
  border: 0;
  height: 1px;
  margin: clamp(26px, 4vw, 42px) 0;
  background: linear-gradient(90deg, var(--c-lake), var(--c-slate) 34%, var(--line-soft) 100%);
  position: relative;
}
.page-about .ab-rule::after {
  content: "";
  position: absolute;
  left: 0;
  top: -3px;
  width: 7px;
  height: 7px;
  background: var(--c-lake);
  border-radius: 50%;
}

/* ---------- 通用章节 ---------- */
.page-about .section {
  padding-top: 6px;
}
.page-about .sec-head {
  display: flex;
  align-items: baseline;
  gap: 12px;
  margin-bottom: 12px;
}
.page-about .sec-index {
  font-size: 13px;
  color: var(--c-lake);
  letter-spacing: .12em;
}
.page-about .section-title {
  margin: 0;
  font-family: var(--font-head);
  font-weight: 800;
  font-size: clamp(21px, 2.6vw, 29px);
  letter-spacing: .04em;
  line-height: 1.34;
  color: var(--c-mist);
}
.page-about .section p {
  font-size: 16px;
  line-height: 1.85;
  color: var(--c-mist);
  margin: 0 0 14px;
  max-width: 42ch;
}
.page-about .section .narrow {
  max-width: 40ch;
}
.page-about .section .small {
  font-size: 13px;
  line-height: 1.75;
  color: var(--c-stone);
  max-width: 40ch;
}
.page-about .section .muted {
  color: var(--c-stone);
}
.page-about .section a {
  color: var(--c-lake);
  text-decoration: none;
  border-bottom: 1px solid var(--line);
  transition: border-color .2s var(--ease), color .2s var(--ease);
}
.page-about .section a:hover {
  color: var(--c-volt);
  border-bottom-color: var(--c-volt);
}

/* ---------- 分栏 ---------- */
.page-about .split {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 22px;
}
.page-about .col-side {
  display: flex;
  flex-direction: column;
  gap: 14px;
}

/* ---------- 统计 ---------- */
.page-about .stat {
  position: relative;
  padding: 14px 16px 14px 20px;
  border: 1px solid var(--line);
  border-radius: var(--r);
  background: var(--c-indigo);
  box-shadow: var(--shadow-card);
  clip-path: polygon(0 0, 100% 0, 100% calc(100% - 10px), calc(100% - 12px) 100%, 0 100%);
}
.page-about .stat::before {
  content: "";
  position: absolute;
  left: 0;
  top: 0;
  bottom: 0;
  width: 3px;
  background: var(--c-gold);
}
.page-about .stat-num {
  display: block;
  font-size: 26px;
  letter-spacing: .02em;
  color: var(--c-gold);
  line-height: 1.1;
}
.page-about .stat-label {
  display: block;
  margin-top: 6px;
  font-size: 13px;
  line-height: 1.65;
  color: var(--c-stone);
}

/* ---------- 反色叠纸块 ---------- */
.page-about .paper-block {
  margin-top: 6px;
  padding: 18px 20px;
  background: var(--c-paper);
  color: var(--c-night-deep);
  border-radius: var(--r);
  border: 1px solid rgba(6, 14, 24, .14);
  box-shadow: 6px 6px 0 rgba(6, 14, 24, .35), 0 1px 0 rgba(255, 255, 255, .4) inset;
  transform: rotate(-.25deg);
}
.page-about .paper-block .paper-key {
  margin: 0 0 10px;
  font-family: var(--font-display);
  font-size: 15px;
  font-weight: 600;
  letter-spacing: .06em;
  color: #6a2a12;
  max-width: none;
}
.page-about .paper-block .tick-list li {
  color: #1a2a3a;
}
.page-about .paper-block .tick-list li::before {
  color: #b0492c;
}
.page-about .paper-inline {
  margin-top: 26px;
  max-width: 62ch;
}

/* ---------- 列表 ---------- */
.page-about .tick-list {
  list-style: none;
  margin: 0;
  padding: 0;
}
.page-about .tick-list li {
  position: relative;
  padding: 0 0 8px 20px;
  font-size: 15px;
  line-height: 1.8;
  color: var(--c-mist);
}
.page-about .tick-list li::before {
  content: "▸";
  position: absolute;
  left: 0;
  top: 0;
  color: var(--c-volt);
  font-size: 13px;
}
.page-about .cross-list {
  list-style: none;
  margin: 0;
  padding: 0;
}
.page-about .cross-list li {
  position: relative;
  padding: 0 0 8px 20px;
  font-size: 15px;
  line-height: 1.8;
  color: var(--c-stone);
}
.page-about .cross-list li::before {
  content: "×";
  position: absolute;
  left: 0;
  top: 0;
  color: var(--c-coral);
  font-family: var(--font-mono);
}

/* ---------- 版本轴 ---------- */
.page-about .axis-figure {
  margin: 0 0 26px;
  border: 1px solid var(--line);
  border-radius: var(--r);
  overflow: hidden;
  background: var(--c-indigo);
  box-shadow: var(--shadow-card);
}
.page-about .axis-figure img {
  display: block;
  width: 100%;
  height: auto;
  aspect-ratio: 16 / 9;
  object-fit: cover;
  opacity: .92;
}

.page-about .version-axis {
  list-style: none;
  margin: 0;
  padding: 0;
  position: relative;
}
.page-about .version-axis::before {
  content: "";
  position: absolute;
  left: 7px;
  top: 12px;
  bottom: 12px;
  width: 2px;
  background: linear-gradient(180deg, var(--c-slate), var(--c-lake) 46%, var(--c-gold) 100%);
  border-radius: 2px;
}
.page-about .axis-node {
  position: relative;
  padding: 0 0 22px 34px;
}
.page-about .axis-node::before {
  content: "";
  position: absolute;
  left: 0;
  top: 6px;
  width: 16px;
  height: 16px;
  border-radius: 50%;
  box-sizing: border-box;
  background: var(--c-night);
  border: 2px solid var(--c-slate);
  z-index: 1;
  transition: background .24s var(--ease), border-color .24s var(--ease);
}
.page-about .axis-node.is-current::before {
  background: var(--c-gold);
  border-color: var(--c-gold);
  box-shadow: 0 0 0 5px rgba(232, 178, 76, .16);
}
.page-about .axis-tick {
  display: inline-block;
  margin-bottom: 8px;
  font-size: 13px;
  letter-spacing: .1em;
  color: var(--c-stone);
  padding: 2px 9px;
  border: 1px solid var(--line);
  border-radius: 999px;
}
.page-about .axis-node.is-current .axis-tick {
  color: var(--c-gold);
  border-color: rgba(232, 178, 76, .42);
  background: rgba(232, 178, 76, .08);
}
.page-about .axis-body h3 {
  margin: 0 0 6px;
  font-family: var(--font-head);
  font-weight: 800;
  font-size: 18px;
  letter-spacing: .03em;
  color: var(--c-mist);
}
.page-about .axis-body p {
  margin: 0 0 10px;
  font-size: 15px;
  line-height: 1.8;
  color: var(--c-stone);
  max-width: 44ch;
}

/* ---------- 折叠 ---------- */
.page-about .collapse > summary {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 5px 12px;
  border: 1px solid var(--line);
  border-radius: 999px;
  background: rgba(47, 182, 196, .06);
  color: var(--c-lake);
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: .04em;
  cursor: pointer;
  list-style: none;
  transition: color .2s var(--ease), border-color .2s var(--ease), background .2s var(--ease);
}
.page-about .collapse > summary::-webkit-details-marker {
  display: none;
}
.page-about .collapse > summary::after {
  content: "+";
  font-size: 13px;
  line-height: 1;
}
.page-about .collapse > summary:hover {
  color: var(--c-volt);
  border-color: rgba(111, 227, 210, .45);
}
.page-about .collapse[open] > summary {
  color: var(--c-gold);
  border-color: rgba(232, 178, 76, .42);
  background: rgba(232, 178, 76, .08);
}
.page-about .collapse[open] > summary::after {
  content: "−";
}
.page-about .collapse-body {
  margin-top: 12px;
  padding: 2px 0 2px 14px;
  border-left: 2px solid var(--c-gold);
}
.page-about .collapse-body .tick-list li {
  font-size: 14px;
  color: var(--c-stone);
  padding-bottom: 6px;
}
.page-about .collapse-body .tick-list li::before {
  color: var(--c-gold);
}

/* ---------- 四条主线卡片 ---------- */
.page-about .lane-grid {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 16px;
  margin: 18px 0 12px;
}
.page-about .lane-card {
  position: relative;
  padding: 20px 20px 18px;
  border: 1px solid var(--line);
  border-radius: var(--r);
  background: var(--c-indigo);
  box-shadow: var(--shadow-card);
}
.page-about .lane-card::before {
  content: "";
  position: absolute;
  left: 0;
  top: 0;
  width: 46px;
  height: 3px;
  background: var(--c-lake);
}
.page-about .lane-card:nth-child(2)::before { background: var(--c-volt); }
.page-about .lane-card:nth-child(3)::before { background: var(--c-gold); }
.page-about .lane-card:nth-child(4)::before { background: var(--c-coral); }
.page-about .lane-idx {
  display: inline-block;
  margin-bottom: 10px;
  font-size: 12px;
  letter-spacing: .12em;
  color: var(--c-stone);
}
.page-about .lane-card h3 {
  margin: 0 0 8px;
  font-family: var(--font-head);
  font-weight: 800;
  font-size: 18px;
  letter-spacing: .04em;
  color: var(--c-mist);
}
.page-about .lane-who {
  margin: 0 0 8px;
  font-size: 13px;
  line-height: 1.7;
  color: var(--c-lake);
  max-width: none;
}
.page-about .lane-card > p:last-child {
  margin: 0;
  font-size: 15px;
  line-height: 1.8;
  color: var(--c-stone);
  max-width: none;
}

/* ---------- 三审流程 ---------- */
.page-about .flow-line {
  list-style: none;
  margin: 0;
  padding: 0;
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 14px;
}
.page-about .flow-step {
  position: relative;
  padding: 18px 18px 16px;
  border: 1px solid var(--line);
  border-radius: var(--r);
  background: linear-gradient(180deg, rgba(20, 42, 69, .95), rgba(11, 26, 46, .95));
  box-shadow: var(--shadow-card);
}
.page-about .flow-idx {
  display: inline-block;
  margin-bottom: 8px;
  font-size: 20px;
  letter-spacing: .06em;
  color: var(--c-volt);
}
.page-about .flow-step h3 {
  margin: 0 0 8px;
  font-family: var(--font-head);
  font-weight: 800;
  font-size: 17px;
  letter-spacing: .04em;
  color: var(--c-mist);
}
.page-about .flow-step p {
  margin: 0 0 10px;
  font-size: 14px;
  line-height: 1.78;
  color: var(--c-stone);
  max-width: none;
}
.page-about .flow-out {
  display: flex;
  align-items: baseline;
  gap: 8px;
  padding-top: 10px;
  border-top: 1px dashed var(--line);
  font-size: 13px;
  color: var(--c-gold) !important;
}
.page-about .flow-out .mono {
  font-size: 11px;
  letter-spacing: .1em;
  color: var(--c-stone);
}
.page-about .flow-figure {
  margin: 0;
  border: 1px solid var(--line);
  border-radius: var(--r);
  overflow: hidden;
  background: var(--c-indigo);
  box-shadow: var(--shadow-card);
}
.page-about .flow-figure img {
  display: block;
  width: 100%;
  height: auto;
  aspect-ratio: 4 / 3;
  object-fit: cover;
}

/* ---------- 团队内容线 ---------- */
.page-about .team-grid {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 12px;
  margin: 18px 0 0;
}
.page-about .team-row {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 8px;
  padding: 16px 18px;
  border-left: 2px solid var(--c-slate);
  background: rgba(20, 42, 69, .55);
  border-radius: 0 var(--r) var(--r) 0;
  transition: border-color .22s var(--ease), background .22s var(--ease);
}
.page-about .team-row:hover {
  border-left-color: var(--c-lake);
  background: rgba(20, 42, 69, .85);
}
.page-about .team-tag {
  font-size: 13px;
  letter-spacing: .08em;
  color: var(--c-lake);
}
.page-about .team-row p {
  margin: 0;
  font-size: 15px;
  line-height: 1.8;
  color: var(--c-stone);
  max-width: none;
}

/* ---------- 承诺对照 ---------- */
.page-about .promise-grid {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 16px;
  margin-top: 8px;
}
.page-about .promise {
  padding: 20px;
  border-radius: var(--r);
  border: 1px solid var(--line);
  background: var(--c-indigo);
  box-shadow: var(--shadow-card);
}
.page-about .promise h3 {
  margin: 0 0 12px;
  font-family: var(--font-head);
  font-weight: 800;
  font-size: 17px;
  letter-spacing: .04em;
}
.page-about .promise-yes {
  border-top: 3px solid var(--c-volt);
}
.page-about .promise-yes h3 {
  color: var(--c-volt);
}
.page-about .promise-no {
  border-top: 3px solid var(--c-coral);
  background: rgba(20, 42, 69, .7);
}
.page-about .promise-no h3 {
  color: var(--c-coral);
}
.page-about .promise .tick-list li,
.page-about .promise .cross-list li {
  font-size: 14.5px;
}

/* ---------- 收束 ---------- */
.page-about .closing {
  margin-top: 26px;
  padding-top: 18px;
  border-top: 1px solid var(--line-soft);
}
.page-about .closing p {
  max-width: 46ch;
}
.page-about .closing-mono {
  font-size: 13px;
  letter-spacing: .08em;
  color: var(--c-stone);
}

/* ---------- 响应式 ---------- */
@media (min-width: 720px) {
  .page-about .lane-grid {
    grid-template-columns: repeat(2, minmax(0, 1fr));
    column-gap: 26px;
    row-gap: 18px;
  }
  .page-about .lane-card.offset-down {
    transform: translateY(26px);
  }
  .page-about .lane-grid + .small {
    margin-top: 42px;
  }
  .page-about .flow-line {
    grid-template-columns: minmax(0, 1fr);
    gap: 18px;
  }
  .page-about .flow-step:not(:last-child)::after {
    content: "";
    position: absolute;
    left: 27px;
    bottom: -11px;
    width: 8px;
    height: 8px;
    border-right: 2px solid var(--c-lake);
    border-bottom: 2px solid var(--c-lake);
    transform: rotate(45deg);
  }
  .page-about .team-row {
    grid-template-columns: 128px minmax(0, 1fr);
    align-items: baseline;
    gap: 18px;
  }
  .page-about .promise-grid {
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }
}

@media (min-width: 880px) {
  .page-about .ab-hero h1 {
    font-size: clamp(32px, 3.6vw, 44px);
  }
  .page-about .split-7-5 {
    grid-template-columns: minmax(0, 7fr) minmax(0, 5fr);
    gap: 40px;
  }
  .page-about .split-8-4 {
    grid-template-columns: minmax(0, 8fr) minmax(0, 4fr);
    gap: 40px;
  }
  .page-about .col-side {
    padding-top: 6px;
  }
  .page-about .flow-line {
    grid-template-columns: minmax(0, 1fr);
    gap: 22px;
  }
  .page-about .flow-step:not(:last-child)::after {
    left: auto;
    right: -58px;
    top: 50%;
    bottom: auto;
    transform: translateY(-50%) rotate(-45deg);
  }
  .page-about .flow-step {
    padding: 22px 22px 20px;
  }
  .page-about .version-axis {
    padding-left: 8px;
  }
  .page-about .axis-node {
    padding-left: 48px;
  }
  .page-about .axis-body {
    max-width: 62ch;
  }
}

@media (min-width: 1080px) {
  .page-about .lane-grid {
    grid-template-columns: repeat(4, minmax(0, 1fr));
    column-gap: 18px;
  }
  .page-about .lane-card.offset-down {
    transform: translateY(34px);
  }
  .page-about .lane-grid + .small {
    margin-top: 52px;
  }
}

@media (prefers-reduced-motion: reduce) {
  .page-about .lane-card.offset-down {
    transform: none;
  }
  .page-about .paper-block {
    transform: none;
  }
  .page-about .collapse > summary,
  .page-about .team-row,
  .page-about .axis-node::before {
    transition: none;
  }
}
</main>