.page-about {
  display: block;
  background: var(--bg);
  color: var(--paper);
  font-family: var(--font-body);
  overflow-x: clip;
}

.page-about [hidden] {
  display: none !important;
}

/* ===== 首屏 ===== */

.page-about .about-hero {
  position: relative;
  padding: clamp(24px, 5vw, 56px) 0 clamp(40px, 7vw, 84px);
  border-bottom: 1px solid var(--line-soft);
  overflow: clip;
}

.page-about .about-hero::after {
  content: "";
  position: absolute;
  top: -25%;
  right: -18%;
  width: min(760px, 78%);
  height: 150%;
  background: radial-gradient(closest-side, rgba(41, 224, 210, 0.13), transparent 72%);
  pointer-events: none;
  z-index: 0;
}

.page-about .about-hero__grid {
  position: relative;
  z-index: 1;
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: clamp(28px, 5vw, 56px);
}

.page-about .about-hero__tag {
  margin: 20px 0 0;
  font-size: 12px;
  letter-spacing: 0.22em;
  color: var(--cyan);
}

.page-about .about-hero__title {
  margin: 12px 0 0;
  max-width: 640px;
  font-family: var(--font-display);
  font-weight: 900;
  font-size: clamp(30px, 6.2vw, 60px);
  line-height: 1.08;
  letter-spacing: -0.02em;
}

.page-about .about-hero__lede {
  margin: 20px 0 0;
  max-width: 60ch;
  font-size: clamp(15px, 1.7vw, 17px);
  line-height: 1.85;
  color: rgba(242, 237, 227, 0.84);
}

.page-about .about-hero__lede + .about-hero__lede {
  margin-top: 12px;
  color: var(--muted);
}

.page-about .about-hero__actions {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
  margin-top: 30px;
}

.page-about .about-hero__rail {
  border-left: 1px solid var(--line);
  padding-left: 24px;
}

.page-about .ab-rail {
  list-style: none;
  margin: 0;
  padding: 0;
  display: grid;
  gap: 24px;
}

.page-about .ab-rail__item {
  position: relative;
  display: grid;
  gap: 5px;
}

.page-about .ab-rail__item::before {
  content: "";
  position: absolute;
  left: -29px;
  top: 6px;
  width: 9px;
  height: 9px;
  border-radius: 50%;
  background: var(--flame);
  box-shadow: 0 0 0 3px rgba(228, 85, 43, 0.18);
}

.page-about .ab-rail__year {
  font-family: var(--font-num);
  font-size: 20px;
  line-height: 1.1;
  letter-spacing: 0.02em;
  color: var(--gold);
}

.page-about .ab-rail__txt {
  font-size: 14px;
  line-height: 1.7;
  color: var(--muted);
}

/* ===== 章节通用 ===== */

.page-about .ab-section {
  position: relative;
  padding: clamp(52px, 8vw, 104px) 0;
}

.page-about .ab-section + .ab-section {
  border-top: 1px solid var(--line-soft);
}

.page-about .ab-section--alt {
  background: linear-gradient(180deg, rgba(12, 42, 36, 0.58), rgba(6, 26, 23, 0) 72%);
}

.page-about .ab-head {
  position: relative;
  display: grid;
  grid-template-columns: 46px minmax(0, 1fr);
  gap: 6px 14px;
  align-items: baseline;
  padding-bottom: 22px;
  margin-bottom: clamp(26px, 4vw, 44px);
  border-bottom: 1px solid var(--line-soft);
}

.page-about .ab-head__idx {
  font-family: var(--font-num);
  font-size: clamp(20px, 3vw, 26px);
  line-height: 1;
  color: var(--gold);
  letter-spacing: 0.04em;
}

.page-about .ab-head__title {
  margin: 0;
  font-family: var(--font-display);
  font-weight: 900;
  font-size: clamp(22px, 3.6vw, 38px);
  line-height: 1.2;
  letter-spacing: -0.01em;
  color: var(--paper);
}

.page-about .ab-head__note {
  grid-column: 2;
  margin: 6px 0 0;
  font-size: 12px;
  letter-spacing: 0.22em;
  color: var(--muted);
}

/* ===== 非对称分栏 ===== */

.page-about .ab-split {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: clamp(24px, 4vw, 44px);
}

.page-about .ab-split--spaced {
  margin-top: clamp(30px, 5vw, 52px);
}

.page-about .ab-prose p {
  margin: 0 0 1.1em;
  max-width: 64ch;
  font-size: clamp(15px, 1.6vw, 17px);
  line-height: 1.85;
  color: rgba(242, 237, 227, 0.84);
}

.page-about .ab-prose p:last-child {
  margin-bottom: 0;
}

/* ===== 玻璃层卡片 ===== */

.page-about .ab-side-card {
  padding: clamp(20px, 3vw, 28px);
  background: var(--glass);
  border: 1px solid var(--cyan-soft);
  border-radius: var(--radius);
  -webkit-backdrop-filter: blur(8px);
  backdrop-filter: blur(8px);
}

.page-about .ab-side-card--plain {
  background: rgba(15, 124, 116, 0.1);
  border-color: var(--line-soft);
}

.page-about .ab-side-card__title {
  margin: 0;
  font-size: 15px;
  font-weight: 600;
  letter-spacing: 0.08em;
  color: var(--cyan);
}

.page-about .ab-side-card__list {
  margin: 18px 0 0;
  display: grid;
  gap: 16px;
}

.page-about .ab-side-card__row dt {
  font-size: 15px;
  font-weight: 600;
  color: var(--paper);
}

.page-about .ab-side-card__row dd {
  margin: 6px 0 0;
  font-size: 14px;
  line-height: 1.75;
  color: var(--muted);
}

.page-about .ab-side-card__link {
  margin-top: 20px;
}

/* ===== 图片 ===== */

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

.page-about .ab-figure img {
  display: block;
  width: 100%;
  max-width: 100%;
  height: auto;
  border: 1px solid var(--line-soft);
  border-radius: var(--radius);
  filter: saturate(0.62) contrast(1.06) brightness(0.94);
}

.page-about .ab-figure--wide {
  margin-bottom: clamp(26px, 4vw, 42px);
}

.page-about .ab-figure__cap {
  margin-top: 10px;
  font-size: 13px;
  line-height: 1.7;
  letter-spacing: 0.06em;
  color: var(--muted);
}

/* ===== 时间轴 ===== */

.page-about .ab-timeline {
  position: relative;
}

.page-about .ab-node {
  border-top: 1px solid var(--line-soft);
}

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

.page-about .ab-node__sum {
  display: grid;
  grid-template-columns: 62px minmax(0, 1fr) 20px;
  gap: 14px;
  align-items: center;
  padding: 20px 0;
  cursor: pointer;
  list-style: none;
}

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

.page-about .ab-node__year {
  font-family: var(--font-num);
  font-size: clamp(20px, 3.4vw, 32px);
  line-height: 1;
  letter-spacing: 0.02em;
  color: var(--gold);
}

.page-about .ab-node__title {
  font-size: clamp(15px, 1.8vw, 18px);
  font-weight: 600;
  line-height: 1.5;
  color: var(--paper);
}

.page-about .ab-node__body {
  padding: 0 0 24px;
  max-width: 62ch;
}

.page-about .ab-node__body p {
  margin: 0;
  font-size: 15px;
  line-height: 1.85;
  color: var(--muted);
}

/* ===== 加减号标记（时间轴 / 流程 / 角色卡共用） ===== */

.page-about .ab-node__flag,
.page-about .ab-step__flag,
.page-about .ab-role__flag {
  position: relative;
  width: 14px;
  height: 14px;
  justify-self: end;
  flex: none;
}

.page-about .ab-node__flag::before,
.page-about .ab-node__flag::after,
.page-about .ab-step__flag::before,
.page-about .ab-step__flag::after,
.page-about .ab-role__flag::before,
.page-about .ab-role__flag::after {
  content: "";
  position: absolute;
  left: 50%;
  top: 50%;
  background: var(--cyan);
  transform: translate(-50%, -50%);
  transition: transform 0.28s var(--ease), opacity 0.28s var(--ease);
}

.page-about .ab-node__flag::before,
.page-about .ab-step__flag::before,
.page-about .ab-role__flag::before {
  width: 14px;
  height: 1.5px;
}

.page-about .ab-node__flag::after,
.page-about .ab-step__flag::after,
.page-about .ab-role__flag::after {
  width: 1.5px;
  height: 14px;
}

.page-about .ab-node[open] .ab-node__flag::after,
.page-about .ab-step[open] .ab-step__flag::after,
.page-about .ab-role[open] .ab-role__flag::after {
  transform: translate(-50%, -50%) rotate(90deg);
  opacity: 0;
}

/* ===== 数据流程 ===== */

.page-about .ab-flow-wrap {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: clamp(26px, 4vw, 44px);
}

.page-about .ab-flow {
  display: grid;
  gap: 14px;
  align-content: start;
}

.page-about .ab-step {
  border-left: 2px solid var(--line-soft);
  padding-left: 18px;
  transition: border-color 0.3s var(--ease);
}

.page-about .ab-step[open] {
  border-left-color: var(--cyan);
}

.page-about .ab-step__sum {
  display: grid;
  grid-template-columns: 40px minmax(0, 1fr) 20px;
  gap: 12px;
  align-items: center;
  padding: 10px 0;
  cursor: pointer;
  list-style: none;
}

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

.page-about .ab-step__no {
  font-family: var(--font-num);
  font-size: 15px;
  letter-spacing: 0.04em;
  color: var(--flame);
}

.page-about .ab-step__title {
  font-size: 16px;
  font-weight: 600;
  line-height: 1.5;
  color: var(--paper);
}

.page-about .ab-step__body {
  padding: 4px 0 18px;
}

.page-about .ab-step__body p {
  margin: 0 0 12px;
  max-width: 56ch;
  font-size: 15px;
  line-height: 1.85;
  color: var(--muted);
}

.page-about .ab-step__out {
  display: inline-block;
  max-width: 100%;
  margin: 0;
  padding: 9px 14px;
  background: var(--paper);
  color: var(--ink);
  border-radius: var(--radius);
  font-size: 13px;
  line-height: 1.55;
}

.page-about .ab-step__outk {
  margin-right: 10px;
  font-family: var(--font-num);
  font-size: 11px;
  letter-spacing: 0.16em;
  color: var(--flame);
}

/* ===== 奶油色插页块 ===== */

.page-about .ab-note-paper {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 14px;
  margin-bottom: clamp(26px, 4vw, 40px);
  padding: clamp(22px, 3.4vw, 34px);
  background: var(--paper);
  color: var(--ink);
  border-radius: var(--radius);
}

.page-about .ab-note-paper__num {
  margin: 0;
  font-family: var(--font-num);
  font-size: clamp(46px, 9vw, 74px);
  line-height: 1;
  letter-spacing: -0.02em;
  color: var(--flame);
}

.page-about .ab-note-paper__lead {
  margin: 0;
  font-size: 16px;
  font-weight: 600;
  letter-spacing: 0.04em;
}

.page-about .ab-note-paper__txt {
  margin: 8px 0 0;
  max-width: 56ch;
  font-size: 14px;
  line-height: 1.8;
  color: var(--paper-ink-soft);
}

/* ===== 岗位筛选与角色卡 ===== */

.page-about .ab-filters {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
  margin-bottom: 22px;
}

.page-about .ab-filters__btn {
  padding: 8px 16px;
  border: 1px solid var(--line-soft);
  border-radius: 999px;
  background: transparent;
  color: var(--muted);
  font-family: var(--font-body);
  font-size: 13px;
  letter-spacing: 0.06em;
  cursor: pointer;
  transition: color 0.24s var(--ease), border-color 0.24s var(--ease), background 0.24s var(--ease);
}

.page-about .ab-filters__btn:hover,
.page-about .ab-filters__btn:focus-visible {
  color: var(--cyan);
  border-color: var(--cyan-soft);
}

.page-about .ab-filters__btn[aria-pressed="true"],
.page-about .ab-filters__btn.is-active {
  background: rgba(41, 224, 210, 0.12);
  border-color: var(--cyan);
  color: var(--cyan);
}

.page-about .ab-roles {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 14px;
}

.page-about .ab-role {
  background: var(--glass);
  border: 1px solid var(--cyan-soft);
  border-radius: var(--radius);
  -webkit-backdrop-filter: blur(8px);
  backdrop-filter: blur(8px);
  overflow: hidden;
}

.page-about .ab-role__sum {
  display: grid;
  grid-template-columns: minmax(0, 1fr) auto 20px;
  gap: 12px;
  align-items: center;
  padding: 18px;
  cursor: pointer;
  list-style: none;
}

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

.page-about .ab-role__name {
  font-size: 16px;
  font-weight: 600;
  line-height: 1.5;
  color: var(--paper);
}

.page-about .ab-role__count {
  font-size: 13px;
  color: var(--muted);
  white-space: nowrap;
}

.page-about .ab-role__count .num {
  font-family: var(--font-num);
  font-size: 30px;
  line-height: 1;
  letter-spacing: 0.02em;
  color: var(--gold);
  margin-right: 4px;
}

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

.page-about .ab-role__job {
  margin: 0;
  max-width: 52ch;
  font-size: 14px;
  line-height: 1.85;
  color: var(--muted);
}

/* ===== 合作数字 ===== */

.page-about .ab-partners {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 14px;
  margin-top: clamp(30px, 5vw, 52px);
}

.page-about .ab-partner {
  padding: 20px 22px;
  border-left: 2px solid var(--gold);
  background: rgba(232, 180, 74, 0.06);
}

.page-about .ab-partner__num {
  margin: 0;
  font-family: var(--font-num);
  font-size: clamp(34px, 6vw, 52px);
  line-height: 1;
  letter-spacing: 0.02em;
  color: var(--gold);
}

.page-about .ab-partner__label {
  margin: 10px 0 0;
  font-size: 14px;
  line-height: 1.7;
  color: var(--muted);
}

/* ===== 服务数据 ===== */

.page-about .ab-stats {
  list-style: none;
  margin: 0;
  padding: 0;
  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-stat {
  display: grid;
  gap: 8px;
  padding: 22px 18px;
  background: var(--bg);
}

.page-about .ab-stat__num {
  font-family: var(--font-num);
  font-size: clamp(26px, 4.4vw, 40px);
  line-height: 1;
  letter-spacing: 0.02em;
  color: var(--cyan);
}

.page-about .ab-stat__label {
  font-size: 13px;
  line-height: 1.6;
  letter-spacing: 0.04em;
  color: var(--muted);
}

/* ===== 收束 ===== */

.page-about .ab-cta {
  padding: clamp(48px, 7vw, 88px) 0 clamp(56px, 8vw, 104px);
  border-top: 1px solid var(--line-soft);
  background: linear-gradient(180deg, rgba(12, 42, 36, 0.7), rgba(6, 26, 23, 0) 85%);
}

.page-about .ab-cta__title {
  margin: 0;
  font-family: var(--font-display);
  font-weight: 900;
  font-size: clamp(22px, 3.6vw, 38px);
  line-height: 1.2;
  letter-spacing: -0.01em;
}

.page-about .ab-cta__text {
  margin: 16px 0 0;
  max-width: 60ch;
  font-size: clamp(15px, 1.6vw, 17px);
  line-height: 1.85;
  color: rgba(242, 237, 227, 0.82);
}

.page-about .ab-cta__actions {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
  margin-top: 30px;
}

/* ===== 断点 ===== */

@media (min-width: 720px) {
  .page-about .ab-roles {
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }

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

  .page-about .ab-note-paper {
    grid-template-columns: auto minmax(0, 1fr);
    align-items: center;
    gap: 30px;
  }

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

  .page-about .ab-node__sum {
    grid-template-columns: 116px minmax(0, 1fr) 20px;
    gap: 24px;
    padding: 24px 0;
  }

  .page-about .ab-node__body {
    padding-left: 140px;
  }
}

@media (min-width: 900px) {
  .page-about .about-hero__grid {
    grid-template-columns: minmax(0, 7fr) minmax(0, 5fr);
    align-items: start;
  }

  .page-about .ab-split {
    grid-template-columns: minmax(0, 7fr) minmax(0, 5fr);
    align-items: start;
  }

  .page-about .ab-flow-wrap {
    grid-template-columns: minmax(0, 7fr) minmax(0, 5fr);
    align-items: start;
  }

  .page-about .ab-figure--tall {
    position: sticky;
    top: 96px;
  }
}

@media (min-width: 1024px) {
  .page-about .ab-head {
    grid-template-columns: 62px minmax(0, 1fr);
    padding-right: 46px;
  }

  .page-about .ab-head__note {
    position: absolute;
    right: 0;
    top: 0;
    grid-column: auto;
    margin: 0;
    height: 100%;
    overflow: hidden;
    writing-mode: vertical-rl;
    text-orientation: mixed;
  }
}

@media (prefers-reduced-motion: reduce) {
  .page-about .ab-node__flag::before,
  .page-about .ab-node__flag::after,
  .page-about .ab-step__flag::before,
  .page-about .ab-step__flag::after,
  .page-about .ab-role__flag::before,
  .page-about .ab-role__flag::after,
  .page-about .ab-step,
  .page-about .ab-filters__btn {
    transition: none;
  }
}