.page-about {
  --ab-rail: 210px;
  background: var(--night);
  color: var(--fog);
  font-family: var(--font-body);
  overflow-x: clip;
}

.page-about h1,
.page-about h2,
.page-about h3,
.page-about p,
.page-about ul,
.page-about ol,
.page-about figure {
  margin: 0;
}

.page-about ul,
.page-about ol {
  list-style: none;
  padding: 0;
}

.page-about a {
  color: inherit;
}

/* ---------- 首屏 ---------- */
.page-about .ab-top {
  padding: clamp(26px, 5vw, 52px) 0 clamp(30px, 5vw, 54px);
  background:
    radial-gradient(120% 90% at 88% -10%, rgba(43, 217, 255, 0.14), transparent 62%),
    linear-gradient(180deg, var(--moss), var(--night) 72%);
  border-bottom: 1px solid var(--line-soft);
}

.page-about .ab-title {
  margin-top: clamp(12px, 2vw, 20px);
  color: var(--fog);
}

.page-about .ab-title__accent {
  color: var(--lime);
  position: relative;
}

.page-about .ab-lead {
  margin-top: clamp(16px, 3vw, 26px);
  max-width: 60ch;
  font-size: clamp(15px, 1.7vw, 17px);
  line-height: 1.8;
  color: rgba(242, 247, 244, 0.8);
}

.page-about .ab-strip {
  margin-top: clamp(24px, 4vw, 40px);
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 1px;
  background: var(--line-soft);
  border: 1px solid var(--line-soft);
}

.page-about .ab-strip__item {
  display: flex;
  flex-direction: column;
  gap: 6px;
  padding: 14px 16px;
  background: rgba(7, 26, 43, 0.78);
}

.page-about .ab-strip__num {
  font-size: clamp(20px, 2.6vw, 28px);
  color: var(--lime);
  line-height: 1;
}

.page-about .ab-strip__label {
  font-size: 11px;
  letter-spacing: 0.12em;
  color: var(--sage);
}

/* ---------- 左窄右宽 ---------- */
.page-about .ab-layout {
  padding-top: clamp(32px, 6vw, 68px);
  padding-bottom: clamp(48px, 8vw, 96px);
  display: block;
}

.page-about .ab-rail {
  padding-bottom: clamp(20px, 4vw, 32px);
  border-bottom: 1px solid var(--line-soft);
  margin-bottom: clamp(24px, 4vw, 40px);
}

.page-about .ab-rail__label {
  font-size: 11px;
  letter-spacing: 0.14em;
  text-transform: uppercase;
  color: var(--sage);
  margin-bottom: 12px;
}

.page-about .ab-rail__label--gap {
  margin-top: 22px;
}

.page-about .ab-rail__list {
  display: flex;
  flex-wrap: wrap;
  gap: 6px 20px;
}

.page-about .ab-rail__link {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  font-size: 14px;
  padding: 4px 0;
  color: rgba(242, 247, 244, 0.76);
  text-decoration: none;
  transition: color 0.18s var(--ease);
}

.page-about .ab-rail__link::before {
  content: "";
  width: 14px;
  height: 1px;
  background: var(--lime);
  opacity: 0.75;
}

.page-about .ab-rail__link:hover,
.page-about .ab-rail__link:focus-visible {
  color: var(--lime);
}

.page-about .ab-year-list {
  display: flex;
  flex-wrap: wrap;
  gap: 6px 16px;
  font-family: var(--font-mono);
  font-size: 12px;
  color: var(--sage);
  font-variant-numeric: tabular-nums;
}

.page-about .ab-year-list li {
  position: relative;
  padding-top: 9px;
}

.page-about .ab-year-list li::before {
  content: "";
  position: absolute;
  top: 0;
  left: 0;
  width: 100%;
  height: 1px;
  background: var(--line);
}

.page-about .ab-year-list .ab-year-list__now {
  color: var(--lime);
}

.page-about .ab-year-list .ab-year-list__now::before {
  height: 2px;
  background: var(--lime);
}

/* ---------- 章节骨架 ---------- */
.page-about .ab-sec {
  padding: clamp(32px, 5vw, 58px) 0;
  border-top: 1px solid var(--line-soft);
}

.page-about .ab-sec:first-child {
  border-top: 0;
  padding-top: 0;
}

.page-about .ab-sec__title {
  margin-top: 12px;
  font-family: var(--font-display);
  font-weight: 300;
  font-size: clamp(25px, 3.6vw, 42px);
  line-height: 1.14;
  letter-spacing: -0.01em;
  color: var(--fog);
}

.page-about .ab-sec__lead {
  margin-top: 14px;
  max-width: 58ch;
  font-size: 15px;
  line-height: 1.78;
  color: rgba(242, 247, 244, 0.74);
}

/* ---------- 起点 ---------- */
.page-about .ab-origin {
  margin-top: clamp(20px, 3vw, 32px);
  display: grid;
  gap: clamp(22px, 3vw, 32px);
}

.page-about .ab-origin__text p + p {
  margin-top: 14px;
}

.page-about .ab-origin__text p {
  font-size: 15px;
  line-height: 1.8;
  color: rgba(242, 247, 244, 0.8);
  max-width: 56ch;
}

.page-about .ab-facts {
  margin-top: 20px;
  display: grid;
  gap: 10px;
}

.page-about .ab-facts li {
  position: relative;
  padding-left: 20px;
  font-size: 14px;
  line-height: 1.65;
  color: rgba(242, 247, 244, 0.78);
}

.page-about .ab-facts li::before {
  content: "";
  position: absolute;
  left: 0;
  top: 0.72em;
  width: 9px;
  height: 2px;
  background: var(--lime);
}

.page-about .ab-origin__figure {
  --fig-h: clamp(196px, 34vw, 320px);
}

.page-about .t6-figure__media {
  overflow: hidden;
}

.page-about .t6-figure__media img {
  display: block;
  width: 100%;
  height: auto;
  object-fit: cover;
}

.page-about .t6-figure__cap {
  font-size: 12px;
  letter-spacing: 0.04em;
  color: var(--sage);
}

/* ---------- 团队 ---------- */
.page-about .ab-roles {
  margin-top: clamp(20px, 3vw, 32px);
  display: grid;
  gap: 1px;
  background: var(--line-soft);
  border: 1px solid var(--line-soft);
}

.page-about .ab-role {
  padding: clamp(18px, 2.6vw, 28px);
  background: var(--moss);
  clip-path: polygon(0 0, 100% 0, 100% calc(100% - var(--cut-sm)), calc(100% - var(--cut-sm)) 100%, 0 100%);
}

.page-about .ab-role__num {
  font-size: clamp(30px, 4vw, 44px);
  line-height: 1;
  color: var(--lime);
}

.page-about .ab-role__name {
  margin-top: 10px;
  font-size: 16px;
  letter-spacing: 0.04em;
  color: var(--fog);
}

.page-about .ab-role__desc {
  margin-top: 10px;
  font-size: 14px;
  line-height: 1.72;
  color: rgba(242, 247, 244, 0.74);
}

.page-about .ab-role__list {
  margin-top: 14px;
  padding-top: 12px;
  border-top: 1px dashed var(--line);
  display: grid;
  gap: 7px;
  font-size: 13px;
  line-height: 1.6;
  color: var(--sage);
}

.page-about .ab-role__list li::before {
  content: "— ";
  color: var(--amber);
}

.page-about .ab-note {
  margin-top: 18px;
  padding-left: 14px;
  border-left: 2px solid var(--amber);
  font-size: 13px;
  line-height: 1.75;
  color: var(--sage);
}

/* ---------- 流程 ---------- */
.page-about .ab-flow {
  position: relative;
  margin-top: clamp(22px, 4vw, 36px);
  display: grid;
  gap: clamp(18px, 2.6vw, 24px);
}

.page-about .ab-flow::before {
  content: "";
  position: absolute;
  left: 12px;
  top: 8px;
  bottom: 8px;
  width: 2px;
  background: linear-gradient(180deg, var(--cyan), var(--blue));
  opacity: 0.55;
}

.page-about .ab-step {
  position: relative;
  padding-left: 38px;
}

.page-about .ab-step__idx {
  position: absolute;
  left: 0;
  top: 0;
  display: grid;
  place-items: center;
  width: 26px;
  height: 26px;
  background: var(--night);
  border: 1px solid rgba(43, 217, 255, 0.5);
  color: var(--cyan);
  font-size: 11px;
  letter-spacing: 0;
}

.page-about .ab-step h3 {
  font-size: 17px;
  letter-spacing: 0.02em;
  color: var(--fog);
}

.page-about .ab-step p {
  margin-top: 8px;
  font-size: 14px;
  line-height: 1.75;
  color: rgba(242, 247, 244, 0.74);
  max-width: 46ch;
}

.page-about .ab-step .ab-step__out {
  margin-top: 12px;
  padding-top: 10px;
  border-top: 1px dashed var(--line);
  font-size: 13px;
  color: var(--lime);
  display: flex;
  align-items: baseline;
  gap: 10px;
}

.page-about .ab-step__out span {
  font-size: 10px;
  letter-spacing: 0.16em;
  color: var(--sage);
}

/* ---------- 节点 ---------- */
.page-about .ab-mile-figure {
  --fig-h: clamp(180px, 30vw, 300px);
  margin-top: clamp(20px, 3vw, 30px);
}

.page-about .ab-miles {
  margin-top: clamp(20px, 3vw, 30px);
  border-top: 1px solid var(--line);
}

.page-about .ab-mile {
  border-bottom: 1px solid var(--line);
}

.page-about .ab-mile__sum {
  display: flex;
  align-items: center;
  gap: 14px;
  padding: 16px 2px;
  cursor: pointer;
  list-style: none;
}

.page-about .ab-mile__sum::-webkit-details-marker {
  display: none;
}

.page-about .ab-mile__year {
  font-size: clamp(18px, 2.2vw, 24px);
  color: var(--lime);
  min-width: 62px;
}

.page-about .ab-mile__name {
  font-size: 15px;
  letter-spacing: 0.02em;
  color: var(--fog);
}

.page-about .ab-mile__mark {
  position: relative;
  margin-left: auto;
  flex: none;
  width: 14px;
  height: 14px;
}

.page-about .ab-mile__mark::before,
.page-about .ab-mile__mark::after {
  content: "";
  position: absolute;
  left: 50%;
  top: 50%;
  background: var(--sage);
  transform: translate(-50%, -50%);
}

.page-about .ab-mile__mark::before {
  width: 13px;
  height: 1px;
}

.page-about .ab-mile__mark::after {
  width: 1px;
  height: 13px;
  transition: transform 0.2s var(--ease);
}

.page-about .ab-mile[open] .ab-mile__mark::before {
  background: var(--amber);
}

.page-about .ab-mile[open] .ab-mile__mark::after {
  transform: translate(-50%, -50%) scaleY(0);
}

.page-about .ab-mile__body {
  padding: 0 2px 20px;
}

.page-about .ab-mile__body p {
  max-width: 62ch;
  font-size: 14px;
  line-height: 1.78;
  color: rgba(242, 247, 244, 0.76);
  border-left: 2px solid var(--line);
  padding-left: 14px;
}

.page-about .ab-mile__sum:hover .ab-mile__name,
.page-about .ab-mile__sum:focus-visible .ab-mile__name {
  color: var(--lime);
}

/* ---------- 生态 ---------- */
.page-about .ab-eco {
  margin-top: clamp(20px, 3vw, 32px);
  display: grid;
  gap: 1px;
  background: var(--line-soft);
  border: 1px solid var(--line-soft);
}

.page-about .ab-eco__node {
  padding: clamp(18px, 2.6vw, 26px);
  background: linear-gradient(180deg, rgba(11, 42, 36, 0.94), rgba(7, 26, 43, 0.96));
}

.page-about .ab-eco__node h3 {
  font-size: 15px;
  letter-spacing: 0.06em;
  color: var(--fog);
}

.page-about .ab-eco__metric {
  margin: 12px 0 10px;
  font-size: clamp(21px, 3vw, 30px);
  line-height: 1;
  color: var(--amber);
}

.page-about .ab-eco__node p {
  font-size: 14px;
  line-height: 1.72;
  color: rgba(242, 247, 244, 0.74);
}

/* ---------- 收束 ---------- */
.page-about .ab-cta {
  padding-top: clamp(34px, 5vw, 56px);
}

.page-about .ab-cta__panel {
  padding: clamp(22px, 4vw, 46px);
}

.page-about .ab-cta__title {
  font-family: var(--font-display);
  font-weight: 300;
  font-size: clamp(23px, 3.3vw, 36px);
  line-height: 1.18;
  color: var(--fog);
}

.page-about .ab-cta__text {
  margin-top: 12px;
  max-width: 54ch;
  font-size: 14px;
  line-height: 1.78;
  color: rgba(242, 247, 244, 0.76);
}

.page-about .ab-cta__actions {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
  margin-top: 22px;
}

/* ---------- 中屏 ---------- */
@media (min-width: 720px) {
  .page-about .ab-strip {
    grid-template-columns: repeat(4, minmax(0, 1fr));
  }

  .page-about .ab-origin {
    grid-template-columns: minmax(0, 1.05fr) minmax(0, 0.95fr);
    align-items: start;
  }

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

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

/* ---------- 大屏：左右分屏 ---------- */
@media (min-width: 920px) {
  .page-about .ab-layout {
    display: grid;
    grid-template-columns: var(--ab-rail) minmax(0, 1fr);
    gap: clamp(34px, 5vw, 78px);
    align-items: start;
  }

  .page-about .ab-rail {
    position: sticky;
    top: 88px;
    padding-bottom: 0;
    border-bottom: 0;
    margin-bottom: 0;
    border-left: 1px solid var(--line-soft);
    padding-left: 22px;
  }

  .page-about .ab-rail__list {
    flex-direction: column;
    flex-wrap: nowrap;
    gap: 2px;
  }

  .page-about .ab-rail__list li {
    width: 100%;
  }

  .page-about .ab-rail__link {
    padding: 6px 0;
  }

  .page-about .ab-year-list {
    flex-direction: column;
    gap: 12px;
  }

  .page-about .ab-year-list li {
    padding-top: 0;
    padding-left: 16px;
  }

  .page-about .ab-year-list li::before {
    top: 0.5em;
    left: 0;
    width: 1px;
    height: 1.4em;
    background: var(--line);
  }

  .page-about .ab-year-list .ab-year-list__now::before {
    width: 2px;
    background: var(--lime);
  }

  .page-about .ab-flow {
    grid-template-columns: repeat(2, minmax(0, 1fr));
    column-gap: clamp(24px, 3.4vw, 44px);
    row-gap: clamp(22px, 3vw, 34px);
  }

  .page-about .ab-flow::before {
    display: none;
  }

  .page-about .ab-step {
    padding-left: 0;
    padding-top: 18px;
    border-top: 1px solid var(--line);
  }

  .page-about .ab-step__idx {
    position: static;
    display: inline-grid;
  }

  .page-about .ab-step h3 {
    margin-top: 12px;
  }
}

@media (prefers-reduced-motion: reduce) {
  .page-about .ab-rail__link,
  .page-about .ab-mile__mark::after {
    transition: none;
  }
}

.page-about {
  --ab-rail: 210px;
  background: var(--night);
  color: var(--fog);
  font-family: var(--font-body);
  overflow-x: clip;
}

.page-about h1,
.page-about h2,
.page-about h3,
.page-about p,
.page-about ul,
.page-about ol,
.page-about figure {
  margin: 0;
}

.page-about ul,
.page-about ol {
  list-style: none;
  padding: 0;
}

.page-about a {
  color: inherit;
}

/* ---------- 首屏 ---------- */
.page-about .ab-top {
  padding: clamp(26px, 5vw, 52px) 0 clamp(30px, 5vw, 54px);
  background:
    radial-gradient(120% 90% at 88% -10%, rgba(43, 217, 255, 0.14), transparent 62%),
    linear-gradient(180deg, var(--moss), var(--night) 72%);
  border-bottom: 1px solid var(--line-soft);
}

.page-about .ab-title {
  margin-top: clamp(12px, 2vw, 20px);
  color: var(--fog);
}

.page-about .ab-title__accent {
  color: var(--lime);
}

.page-about .ab-lead {
  margin-top: clamp(16px, 3vw, 26px);
  max-width: 60ch;
  font-size: clamp(15px, 1.7vw, 17px);
  line-height: 1.8;
  color: rgba(242, 247, 244, 0.8);
}

.page-about .ab-strip {
  margin-top: clamp(24px, 4vw, 40px);
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 1px;
  background: var(--line-soft);
  border: 1px solid var(--line-soft);
}

.page-about .ab-strip__item {
  display: flex;
  flex-direction: column;
  gap: 6px;
  padding: 14px 16px;
  background: rgba(7, 26, 43, 0.78);
}

.page-about .ab-strip__num {
  font-size: clamp(20px, 2.6vw, 28px);
  color: var(--lime);
  line-height: 1;
}

.page-about .ab-strip__label {
  font-size: 11px;
  letter-spacing: 0.12em;
  color: var(--sage);
}

/* ---------- 左窄右宽骨架 ---------- */
.page-about .ab-layout {
  padding-top: clamp(32px, 6vw, 68px);
  padding-bottom: clamp(48px, 8vw, 96px);
  display: block;
}

.page-about .ab-rail {
  padding-bottom: clamp(20px, 4vw, 32px);
  border-bottom: 1px solid var(--line-soft);
  margin-bottom: clamp(24px, 4vw, 40px);
}

.page-about .ab-rail__label {
  font-size: 11px;
  letter-spacing: 0.14em;
  text-transform: uppercase;
  color: var(--sage);
  margin-bottom: 12px;
}

.page-about .ab-rail__label--gap {
  margin-top: 22px;
}

.page-about .ab-rail__list {
  display: flex;
  flex-wrap: wrap;
  gap: 6px 20px;
}

.page-about .ab-rail__link {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  font-size: 14px;
  padding: 4px 0;
  color: rgba(242, 247, 244, 0.76);
  text-decoration: none;
  transition: color 0.18s var(--ease);
}

.page-about .ab-rail__link::before {
  content: "";
  width: 14px;
  height: 1px;
  background: var(--lime);
  opacity: 0.75;
}

.page-about .ab-rail__link:hover,
.page-about .ab-rail__link:focus-visible {
  color: var(--lime);
}

.page-about .ab-year-list {
  display: flex;
  flex-wrap: wrap;
  gap: 6px 16px;
  font-family: var(--font-mono);
  font-size: 12px;
  color: var(--sage);
  font-variant-numeric: tabular-nums;
}

.page-about .ab-year-list li {
  position: relative;
  padding-top: 9px;
}

.page-about .ab-year-list li::before {
  content: "";
  position: absolute;
  top: 0;
  left: 0;
  width: 100%;
  height: 1px;
  background: var(--line);
}

.page-about .ab-year-list .ab-year-list__now {
  color: var(--lime);
}

.page-about .ab-year-list .ab-year-list__now::before {
  height: 2px;
  background: var(--lime);
}

/* ---------- 章节 ---------- */
.page-about .ab-sec {
  padding: clamp(32px, 5vw, 58px) 0;
  border-top: 1px solid var(--line-soft);
}

.page-about .ab-sec:first-child {
  border-top: 0;
  padding-top: 0;
}

.page-about .ab-sec__title {
  margin-top: 12px;
  font-family: var(--font-display);
  font-weight: 300;
  font-size: clamp(25px, 3.6vw, 42px);
  line-height: 1.14;
  letter-spacing: -0.01em;
  color: var(--fog);
}

.page-about .ab-sec__lead {
  margin-top: 14px;
  max-width: 58ch;
  font-size: 15px;
  line-height: 1.78;
  color: rgba(242, 247, 244, 0.74);
}

/* ---------- 起点 ---------- */
.page-about .ab-origin {
  margin-top: clamp(20px, 3vw, 32px);
  display: grid;
  gap: clamp(22px, 3vw, 32px);
}

.page-about .ab-origin__text p {
  font-size: 15px;
  line-height: 1.8;
  color: rgba(242, 247, 244, 0.8);
  max-width: 56ch;
}

.page-about .ab-origin__text p + p {
  margin-top: 14px;
}

.page-about .ab-facts {
  margin-top: 20px;
  display: grid;
  gap: 10px;
}

.page-about .ab-facts li {
  position: relative;
  padding-left: 20px;
  font-size: 14px;
  line-height: 1.65;
  color: rgba(242, 247, 244, 0.78);
}

.page-about .ab-facts li::before {
  content: "";
  position: absolute;
  left: 0;
  top: 0.72em;
  width: 9px;
  height: 2px;
  background: var(--lime);
}

.page-about .ab-origin__figure {
  --fig-h: clamp(196px, 34vw, 320px);
}

.page-about .t6-figure__media {
  overflow: hidden;
}

.page-about .t6-figure__media img {
  display: block;
  width: 100%;
  height: auto;
  object-fit: cover;
}

.page-about .t6-figure__cap {
  font-size: 12px;
  letter-spacing: 0.04em;
  color: var(--sage);
}

/* ---------- 团队 ---------- */
.page-about .ab-roles {
  margin-top: clamp(20px, 3vw, 32px);
  display: grid;
  gap: 1px;
  background: var(--line-soft);
  border: 1px solid var(--line-soft);
}

.page-about .ab-role {
  padding: clamp(18px, 2.6vw, 28px);
  background: var(--moss);
  clip-path: polygon(0 0, 100% 0, 100% calc(100% - var(--cut-sm)), calc(100% - var(--cut-sm)) 100%, 0 100%);
}

.page-about .ab-role__num {
  font-size: clamp(30px, 4vw, 44px);
  line-height: 1;
  color: var(--lime);
}

.page-about .ab-role__name {
  margin-top: 10px;
  font-size: 16px;
  letter-spacing: 0.04em;
  color: var(--fog);
}

.page-about .ab-role__desc {
  margin-top: 10px;
  font-size: 14px;
  line-height: 1.72;
  color: rgba(242, 247, 244, 0.74);
}

.page-about .ab-role__list {
  margin-top: 14px;
  padding-top: 12px;
  border-top: 1px dashed var(--line);
  display: grid;
  gap: 7px;
  font-size: 13px;
  line-height: 1.6;
  color: var(--sage);
}

.page-about .ab-role__list li::before {
  content: "— ";
  color: var(--amber);
}

.page-about .ab-note {
  margin-top: 18px;
  padding-left: 14px;
  border-left: 2px solid var(--amber);
  font-size: 13px;
  line-height: 1.75;
  color: var(--sage);
}

/* ---------- 流程 ---------- */
.page-about .ab-flow {
  position: relative;
  margin-top: clamp(22px, 4vw, 36px);
  display: grid;
  gap: clamp(18px, 2.6vw, 24px);
}

.page-about .ab-flow::before {
  content: "";
  position: absolute;
  left: 12px;
  top: 8px;
  bottom: 8px;
  width: 2px;
  background: linear-gradient(180deg, var(--cyan), var(--blue));
  opacity: 0.55;
}

.page-about .ab-step {
  position: relative;
  padding-left: 38px;
}

.page-about .ab-step__idx {
  position: absolute;
  left: 0;
  top: 0;
  display: grid;
  place-items: center;
  width: 26px;
  height: 26px;
  background: var(--night);
  border: 1px solid rgba(43, 217, 255, 0.5);
  color: var(--cyan);
  font-size: 11px;
  letter-spacing: 0;
}

.page-about .ab-step h3 {
  font-size: 17px;
  letter-spacing: 0.02em;
  color: var(--fog);
}

.page-about .ab-step p {
  margin-top: 8px;
  font-size: 14px;
  line-height: 1.75;
  color: rgba(242, 247, 244, 0.74);
  max-width: 46ch;
}

.page-about .ab-step .ab-step__out {
  margin-top: 12px;
  padding-top: 10px;
  border-top: 1px dashed var(--line);
  font-size: 13px;
  color: var(--lime);
  display: flex;
  align-items: baseline;
  gap: 10px;
}

.page-about .ab-step__out span {
  font-size: 10px;
  letter-spacing: 0.16em;
  color: var(--sage);
}

/* ---------- 版本节点 ---------- */
.page-about .ab-mile-figure {
  --fig-h: clamp(180px, 30vw, 300px);
  margin-top: clamp(20px, 3vw, 30px);
}

.page-about .ab-miles {
  margin-top: clamp(20px, 3vw, 30px);
  border-top: 1px solid var(--line);
}

.page-about .ab-mile {
  border-bottom: 1px solid var(--line);
}

.page-about .ab-mile__sum {
  display: flex;
  align-items: center;
  gap: 14px;
  padding: 16px 2px;
  cursor: pointer;
  list-style: none;
}

.page-about .ab-mile__sum::-webkit-details-marker {
  display: none;
}

.page-about .ab-mile__year {
  font-size: clamp(18px, 2.2vw, 24px);
  color: var(--lime);
  min-width: 62px;
}

.page-about .ab-mile__name {
  font-size: 15px;
  letter-spacing: 0.02em;
  color: var(--fog);
}

.page-about .ab-mile__mark {
  position: relative;
  margin-left: auto;
  flex: none;
  width: 14px;
  height: 14px;
}

.page-about .ab-mile__mark::before,
.page-about .ab-mile__mark::after {
  content: "";
  position: absolute;
  left: 50%;
  top: 50%;
  background: var(--sage);
  transform: translate(-50%, -50%);
}

.page-about .ab-mile__mark::before {
  width: 13px;
  height: 1px;
}

.page-about .ab-mile__mark::after {
  width: 1px;
  height: 13px;
  transition: transform 0.2s var(--ease);
}

.page-about .ab-mile[open] .ab-mile__mark::before {
  background: var(--amber);
}

.page-about .ab-mile[open] .ab-mile__mark::after {
  transform: translate(-50%, -50%) scaleY(0);
}

.page-about .ab-mile__body {
  padding: 0 2px 20px;
}

.page-about .ab-mile__body p {
  max-width: 62ch;
  font-size: 14px;
  line-height: 1.78;
  color: rgba(242, 247, 244, 0.76);
  border-left: 2px solid var(--line);
  padding-left: 14px;
}

.page-about .ab-mile__sum:hover .ab-mile__name,
.page-about .ab-mile__sum:focus-visible .ab-mile__name {
  color: var(--lime);
}

/* ---------- 合作生态 ---------- */
.page-about .ab-eco {
  margin-top: clamp(20px, 3vw, 32px);
  display: grid;
  gap: 1px;
  background: var(--line-soft);
  border: 1px solid var(--line-soft);
}

.page-about .ab-eco__node {
  padding: clamp(18px, 2.6vw, 26px);
  background: linear-gradient(180deg, rgba(11, 42, 36, 0.94), rgba(7, 26, 43, 0.96));
}

.page-about .ab-eco__node h3 {
  font-size: 15px;
  letter-spacing: 0.06em;
  color: var(--fog);
}

.page-about .ab-eco__metric {
  margin: 12px 0 10px;
  font-size: clamp(21px, 3vw, 30px);
  line-height: 1;
  color: var(--amber);
}

.page-about .ab-eco__node p {
  font-size: 14px;
  line-height: 1.72;
  color: rgba(242, 247, 244, 0.74);
}

/* ---------- 收束 ---------- */
.page-about .ab-cta {
  padding-top: clamp(34px, 5vw, 56px);
}

.page-about .ab-cta__panel {
  padding: clamp(22px, 4vw, 46px);
}

.page-about .ab-cta__title {
  font-family: var(--font-display);
  font-weight: 300;
  font-size: clamp(23px, 3.3vw, 36px);
  line-height: 1.18;
  color: var(--fog);
}

.page-about .ab-cta__text {
  margin-top: 12px;
  max-width: 54ch;
  font-size: 14px;
  line-height: 1.78;
  color: rgba(242, 247, 244, 0.76);
}

.page-about .ab-cta__actions {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
  margin-top: 22px;
}

/* ---------- 中屏 ---------- */
@media (min-width: 720px) {
  .page-about .ab-strip {
    grid-template-columns: repeat(4, minmax(0, 1fr));
  }

  .page-about .ab-origin {
    grid-template-columns: minmax(0, 1.05fr) minmax(0, 0.95fr);
    align-items: start;
  }

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

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

/* ---------- 大屏分屏 ---------- */
@media (min-width: 920px) {
  .page-about .ab-layout {
    display: grid;
    grid-template-columns: var(--ab-rail) minmax(0, 1fr);
    gap: clamp(34px, 5vw, 78px);
    align-items: start;
  }

  .page-about .ab-rail {
    position: sticky;
    top: 88px;
    padding-bottom: 0;
    margin-bottom: 0;
    border-bottom: 0;
    border-left: 1px solid var(--line-soft);
    padding-left: 22px;
  }

  .page-about .ab-rail__list {
    flex-direction: column;
    flex-wrap: nowrap;
    gap: 2px;
  }

  .page-about .ab-rail__list li {
    width: 100%;
  }

  .page-about .ab-rail__link {
    padding: 6px 0;
  }

  .page-about .ab-year-list {
    flex-direction: column;
    gap: 12px;
  }

  .page-about .ab-year-list li {
    padding-top: 0;
    padding-left: 16px;
  }

  .page-about .ab-year-list li::before {
    top: 0.45em;
    left: 0;
    width: 1px;
    height: 1.5em;
    background: var(--line);
  }

  .page-about .ab-year-list .ab-year-list__now::before {
    width: 2px;
    background: var(--lime);
  }

  .page-about .ab-flow {
    grid-template-columns: repeat(2, minmax(0, 1fr));
    column-gap: clamp(24px, 3.4vw, 44px);
    row-gap: clamp(22px, 3vw, 34px);
  }

  .page-about .ab-flow::before {
    display: none;
  }

  .page-about .ab-step {
    padding-left: 0;
    padding-top: 18px;
    border-top: 1px solid var(--line);
  }

  .page-about .ab-step__idx {
    position: static;
    display: inline-grid;
  }

  .page-about .ab-step h3 {
    margin-top: 12px;
  }
}

@media (prefers-reduced-motion: reduce) {
  .page-about .ab-rail__link,
  .page-about .ab-mile__mark::after {
    transition: none;
  }
}