.page-about {
  --ab-rule: #D8E2EE;
  --ab-ghost-line: rgba(30, 99, 168, .34);
  --ab-card-line: #E4DCD1;
  display: block;
  background: var(--dag-mist);
  padding-bottom: clamp(40px, 6vw, 76px);
  color: var(--dag-ink);
  overflow-x: clip;
}

/* ---------- 首屏 ---------- */
.page-about .ab-hero {
  position: relative;
  padding: clamp(36px, 5.5vw, 76px) 0 clamp(34px, 4.5vw, 58px);
}
.page-about .ab-hero::before {
  content: "";
  position: absolute;
  inset: 0;
  background: radial-gradient(115% 78% at 86% 4%, rgba(242, 103, 34, .12), rgba(242, 103, 34, 0) 62%);
  pointer-events: none;
}
.page-about .ab-hero > * {
  position: relative;
}
.page-about .ab-hero__label {
  color: var(--dag-link);
}
.page-about .ab-hero__title {
  margin: 16px 0 0;
  max-width: 21ch;
  font-size: clamp(30px, 4.6vw, 56px);
  line-height: 1.16;
  font-weight: 800;
  letter-spacing: -0.022em;
  color: var(--dag-deep);
}
.page-about .ab-hero__lead {
  margin: 24px 0 0;
  max-width: 60ch;
  font-size: clamp(15px, 1.1vw, 17px);
  line-height: 1.86;
  color: var(--dag-ink);
}
.page-about .ab-hero__facts {
  list-style: none;
  margin: 38px 0 0;
  padding: 1px;
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 1px;
  background: var(--ab-rule);
  border: 1px solid var(--ab-rule);
}
.page-about .ab-hero__fact {
  background: var(--dag-paper);
  padding: 16px 18px 18px;
  display: flex;
  flex-direction: column;
  gap: 6px;
}
.page-about .ab-hero__factnum {
  font-size: clamp(22px, 2.4vw, 30px);
  font-weight: 700;
  line-height: 1;
  color: var(--dag-deep);
}
.page-about .ab-hero__facttxt {
  font-size: 13px;
  letter-spacing: .06em;
  color: var(--dag-slate);
}

/* ---------- 章节骨架 ---------- */
.page-about .ab-chapter {
  padding: clamp(42px, 5.5vw, 84px) 0;
}
.page-about .ab-chapter + .ab-chapter {
  border-top: 1px solid var(--ab-rule);
}
.page-about .ab-chapter--last {
  padding-bottom: clamp(20px, 2vw, 32px);
}
.page-about .ab-chapter__grid {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 18px;
}
.page-about .ab-chapter__num {
  font-size: clamp(48px, 7vw, 88px);
  font-weight: 700;
  line-height: .82;
  letter-spacing: -0.05em;
  color: rgba(30, 99, 168, .26);
  user-select: none;
  pointer-events: none;
}
@supports (-webkit-text-stroke: 1px black) {
  .page-about .ab-chapter__num {
    color: transparent;
    -webkit-text-stroke: 1.5px var(--ab-ghost-line);
  }
}
.page-about .ab-chapter__title {
  margin: 0 0 18px;
  font-size: clamp(23px, 2.5vw, 33px);
  line-height: 1.28;
  font-weight: 700;
  letter-spacing: -0.012em;
  color: var(--dag-deep);
}
.page-about .ab-chapter__title::before {
  content: "";
  display: block;
  width: 34px;
  height: 3px;
  margin-bottom: 14px;
  background: var(--dag-orange);
}
.page-about .ab-chapter__body p {
  margin: 0 0 16px;
  max-width: 40em;
  font-size: 16.5px;
  line-height: 1.86;
  color: var(--dag-ink);
}
.page-about .ab-chapter__body p:last-child {
  margin-bottom: 0;
}
.page-about .ab-chapter__lead {
  color: var(--dag-slate) !important;
  font-size: 16px !important;
}
.page-about .ab-chapter__after {
  margin-top: 32px;
}
.page-about .ab-chapter__media {
  margin: 0;
}
.page-about .ab-chapter__media .dag-figure__media {
  overflow: hidden;
  background: var(--dag-navy);
}
.page-about .ab-chapter__media img,
.page-about .ab-figure img {
  display: block;
  width: 100%;
  height: 100%;
  object-fit: cover;
  max-width: 100%;
  height: auto;
}
.page-about .ab-chapter__media .dag-figure__media img,
.page-about .ab-figure .dag-figure__media img {
  height: 100%;
}
.page-about .ab-media-32 { aspect-ratio: 3 / 2; }
.page-about .ab-media-43 { aspect-ratio: 4 / 3; }
.page-about .ab-media-127 { aspect-ratio: 12 / 7; }

/* ---------- 培训要点列表 ---------- */
.page-about .ab-bullets {
  list-style: none;
  margin: 22px 0 22px;
  padding: 0;
  display: grid;
  gap: 10px;
}
.page-about .ab-bullets li {
  position: relative;
  padding-left: 22px;
  font-size: 15.5px;
  line-height: 1.72;
  color: var(--dag-ink);
}
.page-about .ab-bullets li::before {
  content: "";
  position: absolute;
  left: 0;
  top: 10px;
  width: 9px;
  height: 2px;
  background: var(--dag-orange);
}

/* ---------- 服务准则折叠 ---------- */
.page-about .ab-rules {
  margin-top: 26px;
  display: grid;
  gap: 10px;
}
.page-about .ab-rule {
  background: var(--dag-paper);
  border: 1px solid var(--ab-card-line);
}
.page-about .ab-rule__head {
  margin: 0;
}
.page-about .ab-rule__trigger {
  width: 100%;
  display: flex;
  align-items: center;
  gap: 14px;
  padding: 16px 18px;
  border: 0;
  background: transparent;
  text-align: left;
  cursor: pointer;
  font-family: inherit;
  color: var(--dag-deep);
  transition: background-color .25s var(--dag-ease);
}
.page-about .ab-rule__trigger:hover {
  background: rgba(30, 99, 168, .06);
}
.page-about .ab-rule__trigger[aria-expanded="true"] {
  background: rgba(242, 103, 34, .07);
}
.page-about .ab-rule__trigger:focus-visible {
  outline: 2px solid var(--dag-orange);
  outline-offset: -2px;
}
.page-about .ab-rule__idx {
  flex: 0 0 auto;
  font-size: 13px;
  font-weight: 700;
  color: var(--dag-orange);
}
.page-about .ab-rule__title {
  flex: 1 1 auto;
  font-size: 16px;
  font-weight: 600;
  line-height: 1.5;
  letter-spacing: -0.004em;
}
.page-about .ab-rule__mark {
  flex: 0 0 auto;
  position: relative;
  width: 22px;
  height: 22px;
  border: 1px solid var(--dag-line);
  border-radius: 50%;
}
.page-about .ab-rule__mark::before,
.page-about .ab-rule__mark::after {
  content: "";
  position: absolute;
  left: 50%;
  top: 50%;
  background: var(--dag-navy);
  transform: translate(-50%, -50%);
}
.page-about .ab-rule__mark::before {
  width: 10px;
  height: 1.5px;
}
.page-about .ab-rule__mark::after {
  width: 1.5px;
  height: 10px;
  transition: transform .25s var(--dag-ease);
}
.page-about .ab-rule__trigger[aria-expanded="true"] .ab-rule__mark::after {
  transform: translate(-50%, -50%) scaleY(0);
}
.page-about .ab-rule__panel {
  padding: 0 18px 18px 18px;
}
.page-about .ab-rule__panel p {
  margin: 0;
  max-width: 40em;
  font-size: 15px;
  line-height: 1.78;
  color: var(--dag-slate);
}

/* ---------- 覆盖演进展带 ---------- */
.page-about .ab-track {
  list-style: none;
  margin: 0;
  padding: 4px 0 18px;
  display: flex;
  gap: 16px;
  overflow-x: auto;
  overscroll-behavior-x: contain;
  scroll-snap-type: x mandatory;
  -webkit-overflow-scrolling: touch;
  scrollbar-width: thin;
  scrollbar-color: var(--dag-line) transparent;
}
.page-about .ab-track:focus-visible {
  outline: 2px solid var(--dag-orange);
  outline-offset: 4px;
}
.page-about .ab-track::-webkit-scrollbar {
  height: 6px;
}
.page-about .ab-track::-webkit-scrollbar-track {
  background: transparent;
}
.page-about .ab-track::-webkit-scrollbar-thumb {
  background: var(--dag-line);
  border-radius: 999px;
}
.page-about .ab-track__item {
  flex: 0 0 min(78vw, 290px);
  scroll-snap-align: start;
  display: flex;
  flex-direction: column;
  gap: 10px;
  padding: 22px 20px 22px;
  background: var(--dag-paper);
  border: 1px solid var(--ab-card-line);
  border-top: 3px solid var(--dag-navy);
}
.page-about .ab-track__item:last-child {
  border-top-color: var(--dag-orange);
}
.page-about .ab-track__stage {
  color: var(--dag-link);
}
.page-about .ab-track__title {
  margin: 0;
  font-size: 17px;
  font-weight: 700;
  line-height: 1.45;
  letter-spacing: -0.006em;
  color: var(--dag-deep);
}
.page-about .ab-track__item p {
  margin: 0;
  font-size: 14.5px;
  line-height: 1.72;
  color: var(--dag-slate);
}
.page-about .ab-track__dots {
  width: 96px;
  height: 24px;
  margin-top: auto;
}
.page-about .ab-dot-on {
  fill: var(--dag-mint);
}
.page-about .ab-dot-off {
  fill: none;
  stroke: var(--dag-line);
  stroke-width: 1.5;
}

/* ---------- 质检闭环 ---------- */
.page-about .ab-loop {
  margin-top: 30px;
}
.page-about .ab-loop__steps {
  list-style: none;
  margin: 0;
  padding: 0;
  display: grid;
  gap: 26px;
}
.page-about .ab-loop__step {
  position: relative;
  padding-top: 20px;
}
.page-about .ab-loop__step::before {
  content: "";
  position: absolute;
  left: 0;
  top: 0;
  width: 12px;
  height: 12px;
  border-radius: 50%;
  background: var(--dag-paper);
  border: 2px solid var(--dag-orange);
}
.page-about .ab-loop__step::after {
  content: "";
  position: absolute;
  left: 14px;
  right: 0;
  top: 5px;
  border-top: 1px dashed var(--dag-line);
}
.page-about .ab-loop__step:last-child::after {
  border-top-color: transparent;
}
.page-about .ab-loop__step h3 {
  margin: 0 0 8px;
  font-size: 16.5px;
  font-weight: 700;
  letter-spacing: -0.005em;
  color: var(--dag-deep);
}
.page-about .ab-loop__step p {
  margin: 0;
  max-width: 34em;
  font-size: 15px;
  line-height: 1.78;
  color: var(--dag-slate);
}
.page-about .ab-loop__return {
  display: none;
}

.page-about .ab-metrics {
  list-style: none;
  margin: 38px 0 0;
  padding: 24px 0 0;
  border-top: 1px solid var(--ab-rule);
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 20px 18px;
}
.page-about .ab-metrics li {
  display: flex;
  flex-direction: column;
  gap: 6px;
}
.page-about .ab-metrics__num {
  font-size: clamp(22px, 2.2vw, 28px);
  font-weight: 700;
  line-height: 1;
  color: var(--dag-deep);
}
.page-about .ab-metrics em {
  font-style: normal;
  font-size: 13px;
  letter-spacing: .05em;
  color: var(--dag-slate);
}

/* ---------- 服务商标签页 ---------- */
.page-about .ab-tabs {
  margin-top: 26px;
}
.page-about .ab-tabs__list {
  display: flex;
  flex-wrap: wrap;
  gap: 4px;
  border-bottom: 1px solid var(--ab-rule);
}
.page-about .ab-tabs__tab {
  appearance: none;
  border: 0;
  border-bottom: 2px solid transparent;
  margin-bottom: -1px;
  padding: 11px 16px;
  background: transparent;
  font-family: inherit;
  font-size: 14.5px;
  font-weight: 600;
  letter-spacing: .02em;
  color: var(--dag-slate);
  cursor: pointer;
  transition: color .2s var(--dag-ease), border-color .2s var(--dag-ease);
}
.page-about .ab-tabs__tab:hover {
  color: var(--dag-deep);
}
.page-about .ab-tabs__tab[aria-selected="true"] {
  color: var(--dag-orange);
  border-bottom-color: var(--dag-orange);
}
.page-about .ab-tabs__tab:focus-visible {
  outline: 2px solid var(--dag-orange);
  outline-offset: -2px;
}
.page-about .ab-tabs__panel {
  padding: 24px 0 0;
}
.page-about .ab-tabs__panel + .ab-tabs__panel {
  border-top: 1px dashed var(--ab-rule);
  margin-top: 22px;
}
.page-about .ab-tabs__panel ul {
  list-style: none;
  margin: 0;
  padding: 0;
  display: grid;
  gap: 13px;
}
.page-about .ab-tabs__panel li {
  position: relative;
  padding-left: 20px;
  max-width: 42em;
  font-size: 15.5px;
  line-height: 1.78;
  color: var(--dag-ink);
}
.page-about .ab-tabs__panel li::before {
  content: "";
  position: absolute;
  left: 0;
  top: 10px;
  width: 8px;
  height: 8px;
  background: var(--dag-orange);
}

/* ---------- 保障与收尾 ---------- */
.page-about .ab-assure {
  display: grid;
  gap: 22px;
  margin-top: 26px;
}
.page-about .ab-assure__main {
  padding: 30px 26px 32px;
  background: var(--dag-deep);
  color: #E7EFF8;
}
.page-about .ab-assure__main p {
  margin: 0;
  max-width: 34em;
  font-size: 15.5px;
  line-height: 1.84;
  color: #D5E2F1;
}
.page-about .ab-assure__num {
  display: block;
  margin-bottom: 14px;
  font-size: clamp(32px, 3.8vw, 46px);
  font-weight: 700;
  line-height: 1;
  color: var(--dag-amber);
}
.page-about .ab-assure__list p {
  margin: 0 0 16px;
  max-width: 40em;
  font-size: 16px;
  line-height: 1.86;
  color: var(--dag-ink);
}
.page-about .ab-assure__list p:last-child {
  margin-bottom: 0;
}
.page-about .ab-next {
  margin-top: 36px;
  padding-top: 26px;
  border-top: 1px dashed var(--ab-rule);
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  justify-content: space-between;
  gap: 20px;
}
.page-about .ab-next p {
  flex: 1 1 320px;
  margin: 0;
  max-width: 52ch;
  font-size: 15.5px;
  line-height: 1.82;
  color: var(--dag-slate);
}
.page-about .ab-next__actions {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
}
.page-about .ab-links {
  list-style: none;
  margin: 32px 0 0;
  padding: 1px;
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 1px;
  background: var(--ab-rule);
  border: 1px solid var(--ab-rule);
}
.page-about .ab-links a {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 14px;
  padding: 18px 20px;
  background: var(--dag-paper);
  color: var(--dag-deep);
  font-size: 15.5px;
  font-weight: 600;
  text-decoration: none;
  transition: background-color .22s var(--dag-ease);
}
.page-about .ab-links a::after {
  content: "→";
  color: var(--dag-orange);
  font-weight: 700;
}
.page-about .ab-links a:hover {
  background: var(--dag-amber);
}

/* ---------- 桌面栅格 ---------- */
@media (min-width: 720px) {
  .page-about .ab-hero__facts {
    grid-template-columns: repeat(4, minmax(0, 1fr));
  }
  .page-about .ab-rules {
    grid-template-columns: repeat(2, minmax(0, 1fr));
    gap: 12px;
  }
  .page-about .ab-metrics {
    grid-template-columns: repeat(4, minmax(0, 1fr));
  }
  .page-about .ab-links {
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }
  .page-about .ab-assure {
    grid-template-columns: minmax(0, 5fr) minmax(0, 7fr);
    gap: 36px;
    align-items: start;
  }
}

@media (min-width: 960px) {
  .page-about .ab-chapter__grid {
    grid-template-columns: 96px minmax(0, 1fr);
    column-gap: 40px;
    align-items: start;
  }
  .page-about .ab-chapter__grid--split {
    grid-template-columns: 96px minmax(0, 1fr) minmax(0, 1.02fr);
  }
  .page-about .ab-chapter__num {
    grid-column: 1;
    grid-row: 1 / span 3;
  }
  .page-about .ab-chapter__body {
    grid-column: 2;
  }
  .page-about .ab-chapter__body--wide {
    grid-column: 2 / -1;
  }
  .page-about .ab-chapter__media {
    grid-column: 3;
  }
  .page-about .ab-loop__steps {
    grid-template-columns: repeat(4, minmax(0, 1fr));
    gap: 0;
  }
  .page-about .ab-loop__step {
    padding-right: 26px;
  }
  .page-about .ab-loop__step::after {
    border-top-width: 1px;
  }
  .page-about .ab-loop__return {
    display: block;
    width: 100%;
    height: 58px;
    margin-top: 6px;
  }
}

@media (min-width: 1100px) {
  .page-about .ab-track__item {
    flex-basis: 292px;
  }
}

@media (max-width: 560px) {
  .page-about .ab-hero__title {
    max-width: none;
  }
  .page-about .ab-chapter__body p,
  .page-about .ab-assure__list p {
    font-size: 16px;
  }
  .page-about .ab-rule__panel {
    padding-left: 14px;
    padding-right: 14px;
  }
}

@media (prefers-reduced-motion: reduce) {
  .page-about .ab-track {
    scroll-behavior: auto;
  }
  .page-about .ab-rule__mark::after,
  .page-about .ab-rule__trigger,
  .page-about .ab-tabs__tab,
  .page-about .ab-links a {
    transition: none;
  }
}