.page-about {
  --about-radius: var(--yb-r-sm);
  background: var(--yb-surface);
  color: var(--yb-ink);
  overflow-wrap: break-word;
}

.page-about .about-crumb {
  padding-top: var(--yb-gap-1);
  font-size: 13px;
  color: var(--yb-muted);
}

.page-about .about-crumb ol {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
  margin: 0;
  padding: 0;
  list-style: none;
}

.page-about .about-crumb li {
  display: flex;
  align-items: center;
  gap: 8px;
}

.page-about .about-crumb li + li::before {
  content: "/";
  color: var(--yb-line);
}

.page-about .about-crumb a {
  color: var(--yb-muted);
  text-decoration: none;
}

.page-about .about-crumb a:hover {
  color: var(--yb-blue);
}

.page-about .about-crumb [aria-current] {
  color: var(--yb-blue);
  font-weight: 600;
}

/* ---------- 首屏声明 ---------- */

.page-about .about-lead {
  padding-bottom: var(--yb-gap-3);
}

.page-about .about-eyebrow {
  margin: 0;
  font-size: 13px;
  font-weight: 700;
  letter-spacing: 0.14em;
  color: var(--yb-teal);
}

.page-about .about-lead__title {
  margin: 14px 0 22px;
  font-size: clamp(30px, 5.2vw, 56px);
  line-height: 1.14;
  font-weight: 800;
  letter-spacing: -0.022em;
  color: var(--yb-blue);
  max-width: 20em;
}

.page-about .about-lead__text {
  margin: 0;
  max-width: 44em;
  font-size: 17px;
  line-height: 1.75;
  color: var(--yb-muted);
}

.page-about .about-facts {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 16px;
  margin: var(--yb-gap-3) 0 0;
  padding: 0;
  list-style: none;
}

.page-about .about-facts li {
  padding: 18px 20px;
  background: var(--yb-white);
  border: 1px solid var(--yb-line);
  border-radius: var(--about-radius);
}

.page-about .about-facts strong {
  display: block;
  font-size: 30px;
  line-height: 1.2;
  font-weight: 800;
  color: var(--yb-blue);
  font-variant-numeric: tabular-nums;
}

.page-about .about-facts span {
  display: block;
  margin-top: 6px;
  font-size: 13px;
  line-height: 1.5;
  color: var(--yb-muted);
}

/* ---------- 章节骨架 ---------- */

.page-about .about-block {
  padding-top: var(--yb-gap-4);
  padding-bottom: var(--yb-gap-4);
}

.page-about .about-head {
  max-width: 46em;
}

.page-about .about-h2 {
  margin: 12px 0 0;
  font-size: clamp(24px, 3.4vw, 36px);
  line-height: 1.24;
  font-weight: 800;
  letter-spacing: -0.016em;
  color: var(--yb-blue);
}

.page-about .about-sub {
  margin: 14px 0 0;
  font-size: 16px;
  line-height: 1.75;
  color: var(--yb-muted);
}

.page-about .yb-media img {
  display: block;
  width: 100%;
  height: auto;
}

/* ---------- 服务范围 ---------- */

.page-about .about-scope__figure {
  margin: var(--yb-gap-2) 0 0;
  border: 1px solid var(--yb-line);
  border-radius: var(--yb-r-lg);
  overflow: hidden;
  background: var(--yb-ice);
}

.page-about .about-scope__grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: 20px;
  margin-top: var(--yb-gap-2);
}

.page-about .about-scope__card {
  position: relative;
  padding: 26px 24px 24px;
  background: var(--yb-white);
  border: 1px solid var(--yb-line);
  border-radius: var(--yb-r-lg);
  min-width: 0;
}

.page-about .about-scope__num {
  display: block;
  margin-bottom: 12px;
  font-size: 34px;
  line-height: 1;
  font-weight: 800;
  letter-spacing: -0.03em;
  color: var(--yb-ice);
  font-variant-numeric: tabular-nums;
  -webkit-text-stroke: 1px var(--yb-bright);
}

.page-about .about-scope__card h3 {
  margin: 0 0 10px;
  font-size: 19px;
  font-weight: 700;
  color: var(--yb-blue);
}

.page-about .about-scope__card p {
  margin: 0;
  font-size: 15px;
  line-height: 1.75;
  color: var(--yb-muted);
}

.page-about .about-scope__card--wide {
  background: var(--yb-ice);
  border-color: transparent;
  border-left: 4px solid var(--yb-blue);
}

/* ---------- 发展历程 ---------- */

.page-about .about-history {
  background: var(--yb-ice);
}

.page-about .about-history__top {
  display: grid;
  grid-template-columns: 1fr;
  gap: var(--yb-gap-2);
}

.page-about .about-history__figure {
  margin: 0;
  border-radius: var(--yb-r-lg);
  overflow: hidden;
  background: var(--yb-white);
  border: 1px solid var(--yb-line);
}

.page-about .about-timeline {
  display: grid;
  grid-template-columns: 1fr;
  gap: 20px;
  margin: var(--yb-gap-3) 0 0;
  padding: 0;
  list-style: none;
}

.page-about .about-stage {
  display: flex;
  flex-direction: column;
  gap: 8px;
  padding: var(--yb-gap-1);
  background: var(--yb-white);
  border: 1px solid var(--yb-line);
  border-top: 4px solid var(--yb-blue);
  border-radius: var(--about-radius);
  min-width: 0;
}

.page-about .about-stage--bright {
  border-top-color: var(--yb-bright);
}

.page-about .about-stage--teal {
  border-top-color: var(--yb-teal);
}

.page-about .about-stage--warm {
  border-top-color: var(--yb-orange);
}

.page-about .about-stage__year {
  font-size: clamp(30px, 6vw, 44px);
  line-height: 1;
  font-weight: 800;
  letter-spacing: -0.03em;
  color: var(--yb-blue);
  font-variant-numeric: tabular-nums;
}

.page-about .about-stage--bright .about-stage__year {
  color: var(--yb-bright);
}

.page-about .about-stage--teal .about-stage__year {
  color: var(--yb-teal);
}

.page-about .about-stage--warm .about-stage__year {
  color: var(--yb-orange);
}

.page-about .about-stage__name {
  margin: 0;
  font-size: 17px;
  font-weight: 700;
  color: var(--yb-ink);
}

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

.page-about .about-stage__more {
  margin-top: 4px;
}

.page-about .about-stage__more summary {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  font-size: 13px;
  font-weight: 600;
  color: var(--yb-teal);
  cursor: pointer;
  list-style: none;
}

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

.page-about .about-stage__more summary::after {
  content: "+";
  font-size: 15px;
  line-height: 1;
}

.page-about .about-stage__more[open] summary::after {
  content: "−";
}

.page-about .about-stage__more p {
  margin: 10px 0 0;
  padding-left: 12px;
  border-left: 2px solid var(--yb-teal);
  font-size: 14px;
  line-height: 1.72;
  color: var(--yb-muted);
}

/* ---------- 能力矩阵 ---------- */

.page-about .about-filter {
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
  margin-top: var(--yb-gap-3);
  margin-bottom: var(--yb-gap-2);
}

.page-about .about-filter .yb-filter__btn {
  padding: 9px 18px;
  border: 1px solid var(--yb-line);
  border-radius: var(--yb-r-pill);
  background: var(--yb-white);
  color: var(--yb-ink);
  font-size: 14px;
  font-weight: 600;
  cursor: pointer;
  transition: background-color 180ms ease, color 180ms ease, border-color 180ms ease;
}

.page-about .about-filter .yb-filter__btn:hover {
  border-color: var(--yb-bright);
  color: var(--yb-blue);
}

.page-about .about-filter .yb-filter__btn[aria-pressed="true"] {
  background: var(--yb-blue);
  border-color: var(--yb-blue);
  color: var(--yb-white);
}

.page-about .about-capability__grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: 20px;
}

.page-about .about-cap {
  display: flex;
  flex-direction: column;
  gap: 10px;
  padding: var(--yb-gap-1);
  background: var(--yb-white);
  border: 1px solid var(--yb-line);
  border-radius: var(--yb-r-lg);
  min-width: 0;
  transition: border-color 180ms ease, box-shadow 180ms ease;
}

.page-about .about-cap:hover {
  border-color: var(--yb-bright);
  box-shadow: var(--yb-shadow-line);
}

.page-about .about-cap.is-hidden {
  display: none;
}

.page-about .about-cap .yb-tag {
  align-self: flex-start;
}

.page-about .about-cap h3 {
  margin: 0;
  font-size: 17px;
  font-weight: 700;
  color: var(--yb-blue);
}

.page-about .about-cap p {
  margin: 0;
  font-size: 14px;
  line-height: 1.72;
  color: var(--yb-muted);
}

.page-about .about-eco {
  display: grid;
  grid-template-columns: 1fr;
  gap: var(--yb-gap-2);
  margin-top: var(--yb-gap-3);
  padding-top: var(--yb-gap-3);
  border-top: 1px solid var(--yb-line);
}

.page-about .about-eco__figure {
  margin: 0;
  border-radius: var(--yb-r-lg);
  overflow: hidden;
  background: var(--yb-white);
  border: 1px solid var(--yb-line);
}

.page-about .about-eco__text h3 {
  margin: 0 0 12px;
  font-size: 20px;
  font-weight: 700;
  color: var(--yb-blue);
}

.page-about .about-eco__text > p {
  margin: 0 0 18px;
  font-size: 15px;
  line-height: 1.75;
  color: var(--yb-muted);
}

.page-about .about-eco__list {
  display: grid;
  gap: 12px;
  margin: 0;
  padding: 0;
  list-style: none;
}

.page-about .about-eco__list li {
  display: grid;
  grid-template-columns: auto minmax(0, 1fr);
  gap: 14px;
  align-items: baseline;
  padding: 14px 16px;
  background: var(--yb-teal-soft);
  border-radius: var(--about-radius);
}

.page-about .about-eco__list strong {
  font-size: 14px;
  font-weight: 700;
  color: var(--yb-teal);
}

.page-about .about-eco__list span {
  font-size: 14px;
  line-height: 1.65;
  color: var(--yb-muted);
}

/* ---------- 团队与资质 ---------- */

.page-about .about-cred__grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: var(--yb-gap-2);
  margin-top: var(--yb-gap-3);
}

.page-about .about-team {
  padding: var(--yb-gap-2);
  background: var(--yb-white);
  border: 1px solid var(--yb-line);
  border-left: 4px solid var(--yb-blue);
  border-radius: var(--yb-r-lg);
}

.page-about .about-team h3 {
  margin: 0 0 12px;
  font-size: 20px;
  font-weight: 700;
  color: var(--yb-blue);
}

.page-about .about-team > p {
  margin: 0;
  font-size: 15px;
  line-height: 1.75;
  color: var(--yb-muted);
}

.page-about .about-team__stats {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 14px;
  margin: var(--yb-gap-2) 0 0;
}

.page-about .about-team__stats div {
  padding: 14px 16px;
  background: var(--yb-ice);
  border-radius: var(--about-radius);
}

.page-about .about-team__stats dt {
  font-size: 13px;
  line-height: 1.5;
  color: var(--yb-muted);
}

.page-about .about-team__stats dd {
  margin: 6px 0 0;
  font-size: 20px;
  font-weight: 800;
  color: var(--yb-blue);
  font-variant-numeric: tabular-nums;
}

.page-about .about-badges {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(148px, 1fr));
  gap: 16px;
  margin: 0;
  padding: 0;
  list-style: none;
}

.page-about .about-badge {
  display: flex;
  flex-direction: column;
  gap: 8px;
  padding: 20px 18px;
  background: var(--yb-white);
  border: 1px solid var(--yb-line);
  border-radius: var(--about-radius);
  min-width: 0;
  transition: border-color 180ms ease, background-color 180ms ease;
}

.page-about .about-badge:hover {
  border-color: var(--yb-teal);
  background: var(--yb-teal-soft);
}

.page-about .about-badge__mark {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 46px;
  height: 46px;
  border: 2px solid var(--yb-blue);
  border-radius: 50%;
  font-size: 12px;
  font-weight: 800;
  letter-spacing: 0.02em;
  color: var(--yb-blue);
  font-variant-numeric: tabular-nums;
}

.page-about .about-badge h3 {
  margin: 0;
  font-size: 15px;
  font-weight: 700;
  color: var(--yb-ink);
}

.page-about .about-badge p {
  margin: 0;
  font-size: 13px;
  line-height: 1.6;
  color: var(--yb-muted);
}

.page-about .about-badge__more {
  font-size: 12px;
  line-height: 1.6;
  color: var(--yb-teal);
}

/* ---------- 客户场景 ---------- */

.page-about .about-scenes__list {
  display: grid;
  grid-template-columns: 1fr;
  gap: 20px;
  margin: var(--yb-gap-3) 0 0;
  padding: 0;
  list-style: none;
}

.page-about .about-scenes__list li {
  padding: 24px 26px;
  background: var(--yb-white);
  border: 1px solid var(--yb-line);
  border-left: 4px solid var(--yb-teal);
  border-radius: var(--about-radius);
  min-width: 0;
}

.page-about .about-scenes__list h3 {
  margin: 0 0 10px;
  font-size: 18px;
  font-weight: 700;
  color: var(--yb-blue);
}

.page-about .about-scenes__list p {
  margin: 0;
  font-size: 15px;
  line-height: 1.75;
  color: var(--yb-muted);
}

/* ---------- 下一步 ---------- */

.page-about .about-next {
  background: var(--yb-white);
  border-top: 1px solid var(--yb-line);
}

.page-about .about-next__grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: 20px;
  margin: var(--yb-gap-3) 0 0;
  padding: 0;
  list-style: none;
}

.page-about .about-next__grid > li {
  display: flex;
  flex-direction: column;
  gap: 12px;
  padding: var(--yb-gap-1);
  background: var(--yb-surface);
  border: 1px solid var(--yb-line);
  border-radius: var(--yb-r-lg);
  min-width: 0;
}

.page-about .about-next__grid h3 {
  margin: 0;
  font-size: 17px;
  font-weight: 700;
  color: var(--yb-blue);
}

.page-about .about-next__grid p {
  flex: 1;
  margin: 0;
  font-size: 14px;
  line-height: 1.72;
  color: var(--yb-muted);
}

.page-about .about-next__grid a {
  align-self: flex-start;
  text-decoration: none;
}

/* ---------- 响应式 ---------- */

@media (min-width: 640px) {
  .page-about .about-scope__grid {
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }

  .page-about .about-scope__card--wide {
    grid-column: 1 / -1;
  }
}

@media (min-width: 760px) {
  .page-about .about-capability__grid {
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }

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

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

@media (min-width: 900px) {
  .page-about .about-history__top {
    grid-template-columns: minmax(0, 8fr) minmax(0, 4fr);
    align-items: start;
    gap: var(--yb-gap-3);
  }

  .page-about .about-timeline {
    grid-template-columns: repeat(4, minmax(0, 1fr));
    gap: var(--yb-gap-1);
  }

  .page-about .about-eco {
    grid-template-columns: minmax(0, 1fr) minmax(0, 1fr);
    align-items: center;
  }

  .page-about .about-cred__grid {
    grid-template-columns: repeat(2, minmax(0, 1fr));
    align-items: start;
  }
}

@media (min-width: 1040px) {
  .page-about .about-capability__grid {
    grid-template-columns: repeat(3, minmax(0, 1fr));
  }

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

@media (prefers-reduced-motion: reduce) {
  .page-about .about-cap,
  .page-about .about-badge,
  .page-about .about-filter .yb-filter__btn {
    transition: none;
  }
}