.page-about {
  --about-cut: 20px;
  --about-rail: 2px;
  --about-node-w: 250px;
  --about-track-h: 440px;
  background: var(--paper-050);
  color: var(--ink-900);
  font-family: var(--font-body);
  overflow-x: hidden;
}

.page-about .mono,
.page-about .about-hero__ver,
.page-about .about-facts__num,
.page-about .about-kpi__n,
.page-about .zone__num,
.page-about .tl-card__ver,
.page-about .promise__no,
.page-about .promise__metric,
.page-about .cred__no,
.page-about .step__no,
.page-about .next-list__num {
  font-family: var(--font-mono);
  font-variant-numeric: tabular-nums;
}

/* ---------- 面包屑 ---------- */
.page-about .breadcrumb {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 6px;
  font-size: var(--fs-label);
  letter-spacing: .05em;
  color: var(--ink-900);
  opacity: .6;
  padding: 24px 0 0;
  max-width: var(--maxw);
  margin: 0 auto;
}

.page-about .breadcrumb a {
  color: inherit;
  text-decoration: none;
  transition: color var(--dur) var(--ease);
}

.page-about .breadcrumb a:hover {
  color: var(--lake-600);
  opacity: 1;
}

.page-about .breadcrumb__sep {
  opacity: .5;
}

/* ---------- 首屏 ---------- */
.page-about .about-hero {
  display: grid;
  grid-template-columns: 1fr;
  gap: 36px;
  padding: 36px 0 64px;
  border-bottom: 1px solid var(--line-gray);
}

.page-about .about-hero__lead h1 {
  font-family: var(--font-display);
  font-size: clamp(30px, 5.2vw, 52px);
  font-weight: 800;
  line-height: 1.2;
  letter-spacing: -.012em;
  margin: 14px 0 22px;
  max-width: 15em;
}

.page-about .lede {
  font-size: var(--fs-4);
  line-height: 1.78;
  max-width: 58ch;
  margin: 0;
  color: var(--ink-900);
  opacity: .8;
}

.page-about .about-hero__panel {
  background: var(--paper-100);
  border-top: 3px solid var(--lake-600);
  padding: 26px 24px 28px;
  clip-path: polygon(0 0, 100% 0, 100% calc(100% - var(--about-cut)), calc(100% - var(--about-cut)) 100%, 0 100%);
}

.page-about .about-hero__panelLabel {
  font-size: var(--fs-label);
  letter-spacing: .16em;
  text-transform: uppercase;
  color: var(--lake-900);
  opacity: .7;
  margin: 0;
}

.page-about .about-hero__ver {
  font-size: clamp(58px, 10vw, 104px);
  font-weight: 700;
  line-height: .92;
  letter-spacing: -.035em;
  color: var(--lake-600);
  margin: 8px 0 10px;
}

.page-about .about-hero__panelNote {
  font-size: var(--fs-label);
  line-height: 1.6;
  color: var(--ink-900);
  opacity: .66;
  margin: 0 0 22px;
  padding-bottom: 20px;
  border-bottom: 1px solid var(--line-gray);
}

.page-about .about-facts {
  list-style: none;
  margin: 0;
  padding: 0;
  display: grid;
  gap: 14px;
}

.page-about .about-facts li {
  display: grid;
  grid-template-columns: 58px 1fr;
  gap: 12px;
  align-items: baseline;
}

.page-about .about-facts__num {
  font-size: 26px;
  font-weight: 700;
  line-height: 1;
  color: var(--ink-900);
}

.page-about .about-facts__tx {
  font-size: var(--fs-5);
  line-height: 1.55;
  color: var(--ink-900);
  opacity: .78;
}

/* ---------- 通用区块 ---------- */
.page-about .section {
  padding: 68px 0;
}

.page-about .about-head {
  max-width: 720px;
  margin-bottom: 44px;
}

.page-about .about-head h2 {
  font-family: var(--font-display);
  font-size: clamp(25px, 3.6vw, 42px);
  font-weight: 800;
  line-height: 1.22;
  letter-spacing: -.006em;
  margin: 14px 0 16px;
}

.page-about .about-lead {
  font-size: var(--fs-4);
  line-height: 1.75;
  max-width: 58ch;
  margin: 0;
  color: var(--ink-900);
  opacity: .76;
}

/* ---------- 三项承诺 ---------- */
.page-about .promise-list {
  display: grid;
  border-top: 1px solid var(--line-gray);
}

.page-about .promise {
  border-bottom: 1px solid var(--line-gray);
  border-left: 3px solid var(--sutra-teal);
  padding-left: 18px;
  transition: border-left-color var(--dur) var(--ease);
}

.page-about .promise:hover {
  border-left-color: var(--lake-600);
}

.page-about .promise__sum {
  list-style: none;
  cursor: pointer;
  display: grid;
  grid-template-columns: 34px 1fr 20px;
  gap: 12px;
  align-items: start;
  padding: 24px 0;
  transition: color var(--dur) var(--ease);
}

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

.page-about .promise__no {
  font-size: var(--fs-label);
  font-weight: 700;
  color: var(--sutra-teal);
  padding-top: 6px;
  letter-spacing: .06em;
}

.page-about .promise__head {
  font-family: var(--font-display);
  font-size: clamp(18px, 2.4vw, 24px);
  font-weight: 700;
  line-height: 1.42;
}

.page-about .promise__toggle {
  position: relative;
  width: 16px;
  height: 16px;
  margin-top: 6px;
  justify-self: end;
}

.page-about .promise__toggle::before,
.page-about .promise__toggle::after {
  content: "";
  position: absolute;
  background: var(--lake-600);
  transition: transform var(--dur) var(--ease);
}

.page-about .promise__toggle::before {
  left: 0;
  top: 7px;
  width: 16px;
  height: 2px;
}

.page-about .promise__toggle::after {
  left: 7px;
  top: 0;
  width: 2px;
  height: 16px;
}

.page-about .promise[open] .promise__toggle::after {
  transform: scaleY(0);
}

.page-about .promise__body {
  padding: 0 0 26px 46px;
}

.page-about .promise__body p {
  font-size: var(--fs-4);
  line-height: 1.76;
  max-width: 58ch;
  margin: 0 0 16px;
  color: var(--ink-900);
  opacity: .82;
}

.page-about .promise__metric {
  display: inline-block;
  font-size: var(--fs-label);
  line-height: 1.7;
  letter-spacing: .02em;
  color: var(--lake-900);
  background: var(--ochre-100);
  border-left: 3px solid var(--ochre-500);
  padding: 6px 12px;
  margin: 0;
  opacity: 1;
}

/* ---------- 版本时间轴 ---------- */
.page-about .about-version {
  position: relative;
  overflow: hidden;
}

.page-about .about-version__bg {
  position: absolute;
  inset: 0;
  z-index: 0;
  pointer-events: none;
  opacity: .14;
}

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

.page-about .about-version > .container {
  position: relative;
  z-index: 1;
}

.page-about .tl-scroll {
  overflow-x: auto;
  overflow-y: hidden;
  padding-bottom: 12px;
  scrollbar-width: thin;
  scrollbar-color: var(--ochre-500) transparent;
}

.page-about .tl-scroll::-webkit-scrollbar {
  height: 4px;
}

.page-about .tl-scroll::-webkit-scrollbar-thumb {
  background: var(--ochre-500);
}

.page-about .tl-track {
  position: relative;
  display: flex;
  list-style: none;
  margin: 0;
  padding: 0 4px;
  height: var(--about-track-h);
  min-width: max-content;
}

.page-about .tl-track::before {
  content: "";
  position: absolute;
  left: 0;
  right: 0;
  top: 50%;
  height: var(--about-rail);
  margin-top: -1px;
  background: var(--ochre-500);
}

.page-about .tl-node {
  position: relative;
  flex: 0 0 var(--about-node-w);
  height: 100%;
}

.page-about .tl-dot {
  position: absolute;
  left: 0;
  top: 50%;
  width: 12px;
  height: 12px;
  margin-top: -6px;
  background: var(--ochre-500);
  border: 2px solid var(--ochre-500);
  z-index: 2;
  transition: transform var(--dur) var(--ease), box-shadow var(--dur) var(--ease);
}

.page-about .tl-node:hover .tl-dot {
  transform: scale(1.15);
}

.page-about .tl-node--now .tl-dot {
  background: var(--lake-600);
  border-color: var(--lake-600);
  box-shadow: 0 0 0 6px var(--ochre-100);
}

.page-about .tl-stem {
  position: absolute;
  left: 5px;
  width: var(--about-rail);
  background: var(--ochre-500);
}

.page-about .tl-node--up .tl-stem {
  top: calc(50% - 38px);
  height: 32px;
}

.page-about .tl-node--down .tl-stem {
  top: calc(50% + 6px);
  height: 32px;
}

.page-about .tl-card {
  position: absolute;
  left: 0;
  right: 22px;
  background: var(--paper-050);
  border: 1px solid var(--line-gray);
  padding: 16px 16px 18px;
  transition: border-color var(--dur) var(--ease), transform var(--dur) var(--ease);
}

.page-about .tl-node--up .tl-card {
  bottom: calc(50% + 38px);
}

.page-about .tl-node--down .tl-card {
  top: calc(50% + 38px);
}

.page-about .tl-card:hover {
  border-color: var(--lake-600);
  transform: translateY(-2px);
}

.page-about .tl-badge {
  display: inline-block;
  font-size: 11px;
  line-height: 1;
  letter-spacing: .08em;
  padding: 4px 7px;
  margin-bottom: 8px;
  color: var(--sutra-white);
  background: var(--lake-600);
}

.page-about .tl-card__ver {
  font-size: 20px;
  font-weight: 700;
  letter-spacing: .02em;
  color: var(--ochre-500);
  margin: 0 0 6px;
}

.page-about .tl-node--now .tl-card__ver {
  color: var(--lake-600);
}

.page-about .tl-card__title {
  font-family: var(--font-display);
  font-size: 16px;
  font-weight: 700;
  line-height: 1.45;
  margin: 0 0 8px;
}

.page-about .tl-card__text {
  font-size: var(--fs-5);
  line-height: 1.65;
  margin: 0;
  color: var(--ink-900);
  opacity: .72;
}

/* ---------- 团队与片区 ---------- */
.page-about .about-team__grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: 44px;
}

.page-about .about-team__copy h2 {
  font-family: var(--font-display);
  font-size: clamp(25px, 3.6vw, 42px);
  font-weight: 800;
  line-height: 1.22;
  margin: 14px 0 20px;
}

.page-about .about-team__p {
  font-size: var(--fs-4);
  line-height: 1.78;
  max-width: 58ch;
  margin: 0 0 18px;
  color: var(--ink-900);
  opacity: .82;
}

.page-about .about-kpi {
  list-style: none;
  margin: 30px 0 0;
  padding: 20px 0 0;
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: 16px;
  border-top: 1px solid var(--line-gray);
}

.page-about .about-kpi li {
  display: grid;
  gap: 6px;
}

.page-about .about-kpi__n {
  font-size: clamp(24px, 3vw, 34px);
  font-weight: 700;
  line-height: 1;
  color: var(--lake-600);
}

.page-about .about-kpi__t {
  font-size: var(--fs-label);
  line-height: 1.5;
  color: var(--ink-900);
  opacity: .7;
}

.page-about .about-team__figure {
  margin: 0;
}

.page-about .about-team__figure img {
  display: block;
  width: 100%;
  height: auto;
  object-fit: cover;
  clip-path: polygon(0 0, 100% 0, 100% calc(100% - var(--about-cut)), calc(100% - var(--about-cut)) 100%, 0 100%);
}

.page-about .zone-grid {
  list-style: none;
  margin: 18px 0 0;
  padding: 0;
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 8px;
}

.page-about .zone {
  display: flex;
  flex-direction: column;
  justify-content: space-between;
  gap: 10px;
  min-height: 82px;
  padding: 12px 12px 13px;
  color: var(--ink-900);
  transition: transform var(--dur) var(--ease);
  clip-path: polygon(0 0, 100% 0, 100% calc(100% - 10px), calc(100% - 10px) 100%, 0 100%);
}

.page-about .zone--d1 {
  background: var(--paper-100);
  background: color-mix(in srgb, var(--lake-600) 14%, var(--paper-050));
}

.page-about .zone--d2 {
  background: var(--paper-100);
  background: color-mix(in srgb, var(--lake-600) 34%, var(--paper-050));
}

.page-about .zone--d3 {
  background: var(--lake-600);
  background: color-mix(in srgb, var(--lake-600) 68%, var(--paper-050));
  color: var(--sutra-white);
}

.page-about .zone--d4 {
  background: var(--lake-900);
  color: var(--sutra-white);
}

.page-about .zone:hover {
  transform: translateY(-3px);
}

.page-about .zone__name {
  font-size: 12px;
  font-weight: 700;
  line-height: 1.4;
  letter-spacing: .01em;
}

.page-about .zone__num {
  font-size: 16px;
  font-weight: 700;
  line-height: 1;
}

.page-about .zone-note {
  font-size: var(--fs-label);
  line-height: 1.6;
  color: var(--ink-900);
  opacity: .6;
  margin: 14px 0 0;
}

/* ---------- 资质与复核 ---------- */
.page-about .about-credits {
  background: var(--ink-900);
  color: var(--paper-050);
  padding: 72px 0 92px;
  clip-path: polygon(0 0, 100% 0, 100% calc(100% - 28px), calc(100% - 28px) 100%, 0 100%);
}

.page-about .about-credits__head {
  max-width: 760px;
  margin-bottom: 40px;
}

.page-about .about-credits h2 {
  font-family: var(--font-display);
  font-size: clamp(25px, 3.6vw, 40px);
  font-weight: 800;
  line-height: 1.24;
  margin: 14px 0 0;
  color: var(--paper-050);
}

.page-about .eyebrow--light {
  color: var(--ochre-500);
}

.page-about .cred-list {
  list-style: none;
  margin: 0;
  padding: 0;
  display: grid;
  gap: 0;
  border-top: 1px solid color-mix(in srgb, var(--paper-050) 24%, transparent);
}

.page-about .cred {
  padding: 26px 0;
  border-bottom: 1px solid color-mix(in srgb, var(--paper-050) 18%, transparent);
}

.page-about .cred__no {
  font-size: var(--fs-label);
  font-weight: 700;
  letter-spacing: .1em;
  color: var(--ochre-500);
  margin: 0 0 8px;
}

.page-about .cred__title {
  font-family: var(--font-display);
  font-size: var(--fs-3);
  font-weight: 700;
  line-height: 1.42;
  margin: 0 0 10px;
  color: var(--paper-050);
}

.page-about .cred__text {
  font-size: var(--fs-5);
  line-height: 1.72;
  margin: 0;
  max-width: 46ch;
  color: var(--paper-050);
  opacity: .72;
}

/* ---------- 质检与回访 ---------- */
.page-about .about-audit__figure {
  margin: 0 0 44px;
}

.page-about .about-audit__figure img {
  display: block;
  width: 100%;
  height: auto;
  max-height: 400px;
  object-fit: cover;
  clip-path: polygon(0 0, 100% 0, 100% calc(100% - var(--about-cut)), calc(100% - var(--about-cut)) 100%, 0 100%);
}

.page-about .about-audit__grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: 40px;
}

.page-about .about-audit__intro h2 {
  font-family: var(--font-display);
  font-size: clamp(25px, 3.6vw, 40px);
  font-weight: 800;
  line-height: 1.24;
  margin: 14px 0 18px;
}

.page-about .about-audit__intro p {
  font-size: var(--fs-4);
  line-height: 1.78;
  max-width: 46ch;
  margin: 0;
  color: var(--ink-900);
  opacity: .8;
}

.page-about .steps {
  list-style: none;
  margin: 0;
  padding: 0 0 0 24px;
  border-left: var(--about-rail) solid var(--line-gray);
}

.page-about .step {
  position: relative;
  padding: 0 0 30px;
}

.page-about .step:last-child {
  padding-bottom: 0;
}

.page-about .step::before {
  content: "";
  position: absolute;
  left: -31px;
  top: 8px;
  width: 12px;
  height: 12px;
  background: var(--lake-600);
}

.page-about .step__no {
  font-size: var(--fs-label);
  font-weight: 700;
  letter-spacing: .1em;
  color: var(--lake-600);
  margin: 0 0 6px;
}

.page-about .step__title {
  font-family: var(--font-display);
  font-size: var(--fs-3);
  font-weight: 700;
  line-height: 1.4;
  margin: 0 0 8px;
}

.page-about .step__text {
  font-size: var(--fs-5);
  line-height: 1.72;
  margin: 0;
  max-width: 52ch;
  color: var(--ink-900);
  opacity: .76;
}

/* ---------- 延伸入口 ---------- */
.page-about .about-next__grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: 32px;
}

.page-about .about-next__head h2 {
  font-family: var(--font-display);
  font-size: clamp(23px, 3.2vw, 36px);
  font-weight: 800;
  line-height: 1.26;
  margin: 14px 0 16px;
}

.page-about .next-list {
  list-style: none;
  margin: 0;
  padding: 0;
  border-top: 1px solid var(--line-gray);
}

.page-about .next-list li {
  border-bottom: 1px solid var(--line-gray);
}

.page-about .next-list a {
  display: grid;
  grid-template-columns: 38px 1fr;
  gap: 4px 14px;
  padding: 20px 0;
  text-decoration: none;
  color: inherit;
  transition: color var(--dur) var(--ease);
}

.page-about .next-list__num {
  grid-column: 1;
  grid-row: 1 / span 2;
  font-size: var(--fs-label);
  font-weight: 700;
  letter-spacing: .06em;
  color: var(--lake-600);
  padding-top: 3px;
}

.page-about .next-list__label {
  grid-column: 2;
  grid-row: 1;
  font-family: var(--font-display);
  font-size: var(--fs-3);
  font-weight: 700;
  line-height: 1.4;
}

.page-about .next-list__desc {
  grid-column: 2;
  grid-row: 2;
  font-size: var(--fs-5);
  line-height: 1.65;
  color: var(--ink-900);
  opacity: .72;
}

@media (hover: hover) {
  .page-about .next-list a:hover {
    color: var(--lake-600);
  }

  .page-about .next-list a:hover .next-list__label {
    text-decoration: underline;
    text-decoration-thickness: 1px;
    text-underline-offset: 5px;
  }
}

/* ---------- 桌面布局 ---------- */
@media (min-width: 780px) {
  .page-about .zone-grid {
    grid-template-columns: repeat(4, minmax(0, 1fr));
  }

  .page-about .cred-list {
    grid-template-columns: repeat(2, minmax(0, 1fr));
    column-gap: 56px;
  }

  .page-about .cred {
    padding: 30px 0;
  }
}

@media (min-width: 900px) {
  .page-about .section {
    padding: 96px 0;
  }

  .page-about .about-hero {
    grid-template-columns: 7fr 4fr;
    gap: 48px;
    align-items: start;
    padding: 44px 0 84px;
  }

  .page-about .about-hero__panel {
    padding: 30px 28px 32px;
  }

  .page-about .about-team__grid {
    grid-template-columns: 7fr 5fr;
    gap: 56px;
    align-items: start;
  }

  .page-about .about-audit__grid {
    grid-template-columns: 4fr 8fr;
    gap: 56px;
    align-items: start;
  }

  .page-about .about-next__grid {
    grid-template-columns: 4fr 8fr;
    gap: 56px;
    align-items: start;
  }

  .page-about .about-credits {
    padding: 96px 0 116px;
  }
}

@media (min-width: 1080px) {
  .page-about {
    --about-node-w: 260px;
    --about-track-h: 460px;
  }

  .page-about .promise__sum {
    grid-template-columns: 44px 1fr 24px;
    padding: 28px 0;
  }

  .page-about .promise__body {
    padding-left: 56px;
  }
}

@media (prefers-reduced-motion: reduce) {
  .page-about .tl-card,
  .page-about .tl-dot,
  .page-about .zone,
  .page-about .promise,
  .page-about .next-list a {
    transition: none;
  }

  .page-about .zone:hover,
  .page-about .tl-card:hover {
    transform: none;
  }
}