.page-about {
  --about-line: var(--line);
}

.page-about .breadcrumb ol {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
  margin: 0;
  padding: 0;
  list-style: none;
  font-size: 14px;
  color: var(--gray);
}

.page-about .breadcrumb li + li::before {
  content: "/";
  margin-right: 8px;
  color: var(--line);
}

.page-about .breadcrumb a {
  color: var(--blue);
  text-decoration: none;
  border-bottom: 2px solid transparent;
  transition: border-color .18s var(--ease);
}

.page-about .breadcrumb a:hover {
  border-bottom-color: var(--orange);
}

/* ---------- 首屏 ---------- */
.page-about .about-hero {
  padding: 28px 0 56px;
  background: linear-gradient(180deg, var(--mist) 0%, var(--white) 100%);
  border-bottom: var(--bd) solid var(--blue);
}

.page-about .about-hero-grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: 32px;
  margin-top: 28px;
}

.page-about .about-hero-main h1 {
  margin: 12px 0 18px;
  font-size: clamp(2rem, 4.6vw, 3.25rem);
  line-height: 1.12;
  letter-spacing: -.01em;
  color: var(--ink);
}

.page-about .about-hero-actions {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
  margin-top: 24px;
}

.page-about .about-hero-side {
  border: var(--bd) solid var(--blue);
  background: var(--white);
  box-shadow: var(--shadow-hard);
  padding: 20px 22px;
}

.page-about .about-side-list {
  list-style: none;
  margin: 12px 0 0;
  padding: 0;
}

.page-about .about-side-list li {
  display: flex;
  align-items: baseline;
  justify-content: space-between;
  gap: 16px;
  padding: 11px 0;
  border-bottom: 2px solid var(--mist);
  font-size: 15px;
  color: var(--gray);
}

.page-about .about-side-list li:last-child {
  border-bottom: 0;
}

.page-about .about-side-list b {
  font-size: 20px;
  color: var(--ink);
  letter-spacing: -.01em;
}

.page-about .about-hero-side .note {
  margin: 14px 0 0;
}

/* ---------- 平台简介 ---------- */
.page-about .about-what .section-title {
  margin: 10px 0 18px;
}

.page-about .about-facts {
  border: var(--bd) solid var(--blue);
  background: var(--ink);
  color: var(--silver);
  box-shadow: var(--shadow-hard);
  padding: 8px 22px;
  align-self: start;
}

.page-about .fact-row {
  display: flex;
  align-items: baseline;
  gap: 16px;
  padding: 18px 0;
  border-bottom: 2px solid rgba(232, 236, 244, .14);
}

.page-about .fact-row:last-child {
  border-bottom: 0;
}

.page-about .fact-num {
  flex: 0 0 auto;
  font-family: var(--font-mono);
  font-size: 34px;
  font-weight: 700;
  line-height: 1;
  color: var(--orange);
}

.page-about .fact-num em {
  font-style: normal;
  font-size: 20px;
}

.page-about .fact-label {
  font-size: 15px;
  line-height: 1.6;
  color: var(--dim);
}

/* ---------- 发展节点 ---------- */
.page-about .about-timeline {
  position: relative;
  overflow: hidden;
}

.page-about .about-tl-bg {
  position: absolute;
  inset: 0;
  opacity: .22;
  pointer-events: none;
}

.page-about .about-tl-bg img {
  width: 100%;
  height: 100%;
  object-fit: cover;
}

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

.page-about .about-sec-head {
  max-width: 68ch;
}

.page-about .about-sec-head .section-title {
  margin: 10px 0 14px;
}

.page-about .about-lede-light {
  font-size: 17px;
  line-height: 1.75;
  color: var(--dim);
  margin: 0;
}

.page-about .tl-list {
  list-style: none;
  margin: 44px 0 0;
  padding: 0;
}

.page-about .tl-item {
  display: grid;
  grid-template-columns: 44px minmax(0, 1fr);
  gap: 18px;
  padding-bottom: 26px;
}

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

.page-about .tl-marker {
  position: relative;
  display: flex;
  justify-content: center;
  padding-top: 22px;
}

.page-about .tl-marker::before {
  content: "";
  position: absolute;
  top: 0;
  bottom: -26px;
  left: 50%;
  width: 2px;
  transform: translateX(-50%);
  background: var(--dim-strong);
}

.page-about .tl-item:last-child .tl-marker::before {
  bottom: calc(100% - 24px);
}

.page-about .tl-node {
  position: relative;
  z-index: 1;
  width: 14px;
  height: 14px;
  border: 2px solid var(--silver);
  border-radius: 2px;
  background: var(--blue);
}

@supports (animation-timeline: view()) {
  @media (prefers-reduced-motion: no-preference) {
    .page-about .tl-node {
      animation: about-node-on linear both;
      animation-timeline: view();
      animation-range: entry 40% cover 45%;
    }
  }
}

@keyframes about-node-on {
  from {
    background: var(--blue);
    box-shadow: 0 0 0 0 rgba(255, 106, 26, 0);
  }
  to {
    background: var(--orange);
    box-shadow: 0 0 0 5px rgba(255, 106, 26, .2);
  }
}

.page-about .tl-body {
  border: var(--bd) solid rgba(232, 236, 244, .26);
  background: rgba(10, 20, 40, .78);
  border-radius: var(--radius);
  padding: 18px 20px;
}

.page-about .tl-year {
  margin: 0 0 6px;
  font-size: 15px;
  letter-spacing: .08em;
  color: var(--orange);
}

.page-about .tl-body .card-title {
  margin: 0 0 10px;
  color: var(--white);
  font-size: 22px;
}

.page-about .tl-body p {
  margin: 0;
  font-size: 16px;
  line-height: 1.75;
  color: var(--dim);
}

/* ---------- 团队与职能 ---------- */
.page-about .team-diagram {
  position: relative;
  margin-top: 34px;
}

.page-about .team-hub {
  position: relative;
  z-index: 1;
  display: flex;
  flex-wrap: wrap;
  align-items: baseline;
  justify-content: space-between;
  gap: 10px 24px;
  border: var(--bd) solid var(--blue);
  background: var(--blue);
  color: var(--white);
  padding: 20px 24px;
  box-shadow: var(--shadow-hard);
}

.page-about .team-hub-title {
  font-size: 22px;
  font-weight: 700;
  letter-spacing: -.01em;
}

.page-about .team-hub-meta {
  font-size: 14px;
  color: var(--silver);
}

.page-about .team-branches {
  position: relative;
  display: grid;
  grid-template-columns: 1fr;
  gap: 16px;
  padding-top: 28px;
  margin-top: 0;
}

.page-about .team-card {
  border: var(--bd) solid var(--blue);
  background: var(--white);
  border-radius: var(--radius);
  transition: box-shadow .18s var(--ease), transform .18s var(--ease);
}

.page-about .team-card summary {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 12px;
  padding: 16px 18px;
  cursor: pointer;
  list-style: none;
  font-size: 17px;
  font-weight: 700;
  color: var(--ink);
}

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

.page-about .team-card summary::after {
  content: "＋";
  font-size: 16px;
  color: var(--orange);
  line-height: 1;
}

.page-about .team-card[open] summary::after {
  content: "－";
}

.page-about .team-card[open] {
  box-shadow: var(--shadow-hard);
}

.page-about .team-card p {
  margin: 0;
  padding: 0 18px 18px;
  font-size: 15px;
  line-height: 1.75;
  color: var(--gray);
}

.page-about .about-flow {
  display: grid;
  grid-template-columns: 1fr;
  margin-top: 34px;
  border: var(--bd) solid var(--blue);
  background: var(--white);
  box-shadow: var(--shadow-sm);
}

.page-about .flow-step {
  display: flex;
  flex-direction: column;
  gap: 6px;
  padding: 18px 20px;
  border-bottom: 2px dashed var(--about-line);
  font-size: 15px;
  color: var(--gray);
}

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

.page-about .flow-step .num {
  font-family: var(--font-mono);
  font-size: 13px;
  color: var(--orange);
  letter-spacing: .1em;
}

.page-about .flow-step b {
  font-size: 16px;
  color: var(--ink);
}

.page-about .about-figure {
  margin: 32px 0 0;
  border: var(--bd) solid var(--blue);
  box-shadow: var(--shadow-hard);
  background: var(--white);
}

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

/* ---------- 资质与认证 ---------- */
.page-about .cert-grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: 18px;
  margin-top: 32px;
}

.page-about .cert-card {
  position: relative;
  border: var(--bd) solid var(--blue);
  background: var(--white);
  border-radius: var(--radius);
  padding: 22px 22px 24px;
  transition: box-shadow .18s var(--ease), transform .18s var(--ease);
}

.page-about .cert-card:hover,
.page-about .cert-card:focus-within {
  transform: translate(-2px, -2px);
  box-shadow: var(--shadow-hard);
  outline: none;
}

.page-about .cert-card .card-title {
  margin: 0 0 8px;
  font-size: 20px;
}

.page-about .cert-card .card-meta {
  display: inline-block;
  font-family: var(--font-mono);
  font-size: 13px;
  letter-spacing: .04em;
  color: var(--teal);
  background: var(--mist);
  border: 2px solid var(--line);
  border-radius: var(--radius);
  padding: 3px 10px;
  margin: 0;
}

.page-about .cert-badge {
  position: relative;
  display: block;
  width: 42px;
  height: 42px;
  margin-bottom: 16px;
  border: 2px solid var(--blue);
  border-radius: var(--radius);
}

.page-about .cert-badge::before {
  content: "";
  position: absolute;
  inset: 9px;
  background: var(--cyan);
  border-radius: 2px;
}

.page-about .cert-badge::after {
  content: "";
  position: absolute;
  top: 50%;
  left: -8px;
  width: 8px;
  height: 2px;
  background: var(--blue);
  transform: translateY(-50%);
}

.page-about .cert-detail {
  margin-top: 14px;
  padding-top: 14px;
  border-top: 2px solid var(--mist);
  font-size: 14.5px;
  line-height: 1.7;
  color: var(--gray);
}

@media (hover: hover) and (min-width: 860px) {
  .page-about .cert-detail {
    max-height: 0;
    margin-top: 0;
    padding-top: 0;
    border-top-width: 0;
    opacity: 0;
    overflow: hidden;
    transition: max-height .22s var(--ease), opacity .22s var(--ease),
                margin-top .22s var(--ease), padding-top .22s var(--ease),
                border-top-width .22s var(--ease);
  }

  .page-about .cert-card:hover .cert-detail,
  .page-about .cert-card:focus-within .cert-detail {
    max-height: 240px;
    margin-top: 14px;
    padding-top: 14px;
    border-top-width: 2px;
    opacity: 1;
  }
}

.page-about .about-figure--cert {
  margin-top: 34px;
}

/* ---------- 服务覆盖与合作 ---------- */
.page-about .cover-grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: 18px;
  margin-top: 36px;
}

.page-about .cover-stat {
  display: flex;
  flex-direction: column;
  gap: 12px;
  border: 2px solid rgba(232, 236, 244, .28);
  border-left: 4px solid var(--cyan);
  padding: 22px;
}

.page-about .cover-stat .stat-num {
  font-family: var(--font-mono);
  font-size: 40px;
  font-weight: 700;
  line-height: 1;
  color: var(--orange);
}

.page-about .cover-stat .stat-num em {
  font-style: normal;
  font-size: 22px;
}

.page-about .cover-stat .stat-label {
  font-size: 15px;
  line-height: 1.7;
  color: var(--dim);
}

.page-about .cover-foot {
  display: grid;
  gap: 20px;
  align-items: start;
  margin-top: 32px;
  padding-top: 28px;
  border-top: 2px solid rgba(232, 236, 244, .2);
}

.page-about .cover-foot p {
  margin: 0;
  font-size: 16px;
  line-height: 1.75;
  color: var(--dim);
  max-width: 68ch;
}

/* ---------- 服务原则 ---------- */
.page-about .principle-list {
  display: grid;
  grid-template-columns: 1fr;
  gap: 18px;
  margin-top: 32px;
}

.page-about .principle {
  display: flex;
  flex-direction: column;
  gap: 12px;
  border: var(--bd) solid var(--blue);
  border-top: 6px solid var(--orange);
  background: var(--white);
  border-radius: var(--radius);
  padding: 22px;
}

.page-about .principle-num {
  font-size: 13px;
  letter-spacing: .12em;
  color: var(--orange);
}

.page-about .principle .card-title {
  margin: 0;
  font-size: 22px;
}

.page-about .principle p {
  margin: 0;
  font-size: 15.5px;
  line-height: 1.75;
  color: var(--gray);
}

.page-about .principle-case {
  margin-top: auto;
  background: var(--mist);
  border-left: 3px solid var(--blue);
  border-radius: 0 var(--radius) var(--radius) 0;
  padding: 12px 14px;
  font-size: 14.5px;
  line-height: 1.65;
  color: var(--gray);
}

.page-about .principle-case b {
  color: var(--ink);
}

/* ---------- 底部行动区 ---------- */
.page-about .about-next {
  padding-bottom: 64px;
}

.page-about .about-cta {
  display: grid;
  gap: 24px;
  border: var(--bd) solid var(--blue);
  background: var(--ink);
  color: var(--silver);
  border-radius: var(--radius);
  padding: 28px 24px;
  box-shadow: var(--shadow-hard-ink);
}

.page-about .about-cta .section-title {
  margin: 10px 0 12px;
}

.page-about .about-cta p {
  margin: 0;
  font-size: 16px;
  line-height: 1.75;
  color: var(--dim);
  max-width: 62ch;
}

.page-about .about-cta-actions {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
}

/* ---------- 响应式 ---------- */
@media (min-width: 700px) {
  .page-about .about-flow {
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }

  .page-about .flow-step {
    border-bottom: 0;
    border-left: 2px dashed var(--about-line);
    border-bottom: 2px dashed var(--about-line);
  }

  .page-about .flow-step:nth-child(odd) {
    border-left: 0;
  }

  .page-about .flow-step:nth-last-child(-n+2) {
    border-bottom: 0;
  }

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

  .page-about .cert-grid .cert-card:last-child {
    grid-column: 1 / -1;
  }
}

@media (min-width: 900px) {
  .page-about .about-hero {
    padding: 36px 0 72px;
  }

  .page-about .about-hero-grid {
    grid-template-columns: minmax(0, 7fr) minmax(0, 4fr);
    gap: 56px;
    align-items: start;
  }

  .page-about .tl-item {
    grid-template-columns: 60px minmax(0, 1fr);
    gap: 26px;
    padding-bottom: 32px;
  }

  .page-about .tl-marker::before {
    bottom: -32px;
  }

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

  .page-about .team-branches::before {
    content: "";
    position: absolute;
    top: 0;
    left: 12.5%;
    right: 12.5%;
    height: 2px;
    background: var(--blue);
  }

  .page-about .team-hub::after {
    content: "";
    position: absolute;
    left: 50%;
    bottom: -28px;
    width: 2px;
    height: 28px;
    background: var(--blue);
    transform: translateX(-50%);
  }

  .page-about .team-card::before {
    content: "";
    position: absolute;
    top: -28px;
    left: 50%;
    width: 2px;
    height: 28px;
    background: var(--blue);
    transform: translateX(-50%);
  }

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

  .page-about .flow-step {
    border-left: 2px dashed var(--about-line);
    border-bottom: 0;
  }

  .page-about .flow-step:nth-child(odd) {
    border-left: 2px dashed var(--about-line);
  }

  .page-about .flow-step:first-child {
    border-left: 0;
  }

  .page-about .flow-step:nth-last-child(-n+2) {
    border-bottom: 0;
  }

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

  .page-about .cert-grid .cert-card:last-child {
    grid-column: auto;
  }

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

  .page-about .cover-foot {
    grid-template-columns: minmax(0, 1fr) auto;
    align-items: center;
    gap: 40px;
  }

  .page-about .about-cta {
    grid-template-columns: minmax(0, 1fr) auto;
    align-items: center;
    padding: 36px 40px;
  }

  .page-about .about-cta-actions {
    justify-content: flex-end;
  }
}

@media (min-width: 1100px) {
  .page-about .about-fact-row,
  .page-about .fact-num {
    font-size: 38px;
  }
}
</style>