.page-about {
  background: var(--bg);
  color: var(--ink);
  font-family: var(--font-body);
  padding: clamp(1rem, 3vw, 2rem) 0 clamp(2.5rem, 6vw, 4.5rem);
}

.page-about .about-shell {
  width: 100%;
  max-width: var(--shell);
  margin-inline: auto;
  padding-inline: var(--gutter);
}

/* ---------- 面包屑 ---------- */
.page-about .about-crumb {
  margin-bottom: clamp(0.9rem, 2vw, 1.4rem);
}

.page-about .about-crumb .breadcrumb {
  font-size: 0.78rem;
  letter-spacing: 0.02em;
}

/* ---------- 首屏 ---------- */
.page-about .about-hero {
  position: relative;
  padding-bottom: clamp(1.6rem, 4vw, 2.6rem);
  border-bottom: 1px solid var(--line);
}

.page-about .about-hero::after {
  content: "";
  position: absolute;
  left: 0;
  right: 0;
  bottom: -1px;
  height: 9px;
  background-image: repeating-linear-gradient(
    to right,
    var(--line) 0 1px,
    transparent 1px 26px
  );
  pointer-events: none;
}

.page-about .about-hero h1 {
  font-family: var(--font-display);
  font-size: clamp(1.9rem, 6.2vw, 3.5rem);
  line-height: 1.12;
  letter-spacing: 0.005em;
  margin: 0.55rem 0 0;
  max-width: 24ch;
  color: var(--ink);
}

.page-about .about-lede {
  margin: 1rem 0 0;
  max-width: 62ch;
  color: var(--muted);
  font-size: clamp(0.95rem, 2.2vw, 1.04rem);
  line-height: 1.78;
}

.page-about .about-facts {
  list-style: none;
  margin: clamp(1.4rem, 3.5vw, 2rem) 0 0;
  padding: 0;
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 1px;
  background: var(--line);
  border: 1px solid var(--line);
  border-radius: var(--radius-md);
  overflow: hidden;
}

.page-about .about-facts li {
  display: flex;
  flex-direction: column;
  gap: 0.3rem;
  min-width: 0;
  padding: 0.9rem 1rem;
  background: var(--panel);
}

.page-about .about-fact-num {
  font-size: clamp(1.4rem, 4.4vw, 1.85rem);
  line-height: 1;
  color: var(--ink);
  font-variant-numeric: tabular-nums;
}

.page-about .about-fact-num em {
  font-style: normal;
  font-size: 0.55em;
  margin-left: 0.1em;
  color: var(--muted);
}

.page-about .about-facts li:nth-child(2) .about-fact-num {
  color: var(--blue);
}

.page-about .about-facts li:nth-child(3) .about-fact-num {
  color: var(--green);
}

.page-about .about-fact-label {
  font-size: 0.76rem;
  letter-spacing: 0.04em;
  color: var(--muted);
}

/* ---------- 主体两栏 ---------- */
.page-about .about-body {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: clamp(1.4rem, 4vw, 3rem);
  padding-top: clamp(1.6rem, 4vw, 2.8rem);
}

.page-about .about-index {
  min-width: 0;
}

.page-about .about-index-label {
  margin: 0 0 0.6rem;
  font-family: var(--font-mono);
  font-size: var(--step-label);
  letter-spacing: 0.14em;
  text-transform: uppercase;
  color: var(--muted);
}

.page-about .about-index-list {
  list-style: none;
  margin: 0;
  padding: 0 0 0.5rem;
  display: flex;
  gap: 0.45rem;
  overflow-x: auto;
  scrollbar-width: none;
}

.page-about .about-index-list::-webkit-scrollbar {
  display: none;
}

.page-about .about-index-list li {
  flex: 0 0 auto;
}

.page-about .about-index-link {
  display: inline-flex;
  align-items: center;
  gap: 0.45rem;
  padding: 0.42rem 0.8rem;
  border: 1px solid var(--line);
  border-radius: var(--radius-pill);
  color: var(--muted);
  text-decoration: none;
  font-size: 0.84rem;
  white-space: nowrap;
  transition: color var(--dur), border-color var(--dur), background-color var(--dur);
}

.page-about .about-index-link:hover,
.page-about .about-index-link:focus-visible {
  color: var(--ink);
  border-color: var(--green);
  background: var(--green-deep);
}

.page-about .about-index-num {
  font-size: 0.7rem;
  letter-spacing: 0.08em;
  color: var(--green);
}

.page-about .about-content {
  min-width: 0;
}

/* ---------- 章节 ---------- */
.page-about .about-section {
  border-top: 1px solid var(--line);
  padding-block: clamp(1.8rem, 4.5vw, 2.8rem);
  scroll-margin-top: calc(var(--header-h) + 1rem);
}

.page-about .about-content > .about-section:first-child {
  border-top: 0;
  padding-top: 0;
}

.page-about .about-title {
  display: flex;
  align-items: baseline;
  gap: 0.7rem;
  margin: 0 0 0.9rem;
  font-family: var(--font-display);
  font-size: var(--step-h2);
  line-height: 1.28;
  color: var(--ink);
}

.page-about .about-step {
  flex: 0 0 auto;
  font-size: 0.78rem;
  letter-spacing: 0.08em;
  color: var(--green);
  transform: translateY(-0.1em);
}

.page-about .about-text {
  margin: 0 0 1rem;
  max-width: 66ch;
  color: var(--muted);
  font-size: 0.96rem;
  line-height: 1.78;
}

.page-about .about-text a {
  color: var(--blue);
  text-decoration: none;
  border-bottom: 1px solid rgba(39, 199, 255, 0.35);
}

.page-about .about-text a:hover {
  color: var(--green);
  border-bottom-color: rgba(182, 255, 60, 0.5);
}

.page-about .about-text--tail {
  margin: 1.4rem 0 0;
  font-size: 0.88rem;
}

.page-about .about-subtitle {
  margin: 1.8rem 0 0.8rem;
  font-family: var(--font-display);
  font-size: 1rem;
  letter-spacing: 0.04em;
  color: var(--ink);
}

/* ---------- 三条产品线 ---------- */
.page-about .lineup {
  list-style: none;
  margin: 1.4rem 0 0;
  padding: 0;
  display: grid;
  gap: 0.75rem;
  grid-template-columns: minmax(0, 1fr);
}

.page-about .lineup-item {
  display: flex;
  flex-direction: column;
  gap: 0.55rem;
  min-width: 0;
  padding: 1.05rem 1rem;
  background: var(--panel);
  border: 1px solid var(--line);
  border-radius: var(--radius-md);
  transition: border-color var(--dur), background-color var(--dur);
}

.page-about .lineup-item:hover {
  border-color: rgba(182, 255, 60, 0.45);
  background: var(--panel-2);
}

.page-about .lineup-key {
  padding-left: 0.6rem;
  border-left: 2px solid var(--green);
  font-family: var(--font-display);
  font-size: 0.95rem;
  letter-spacing: 0.06em;
  line-height: 1.2;
  color: var(--ink);
}

.page-about .lineup-item p {
  margin: 0;
  font-size: 0.9rem;
  line-height: 1.7;
  color: var(--muted);
}

.page-about .lineup-link {
  margin-top: auto;
  font-family: var(--font-mono);
  font-size: 0.78rem;
  letter-spacing: 0.05em;
  color: var(--blue);
  text-decoration: none;
}

.page-about .lineup-link:hover {
  color: var(--green);
}

/* ---------- 数据流程 ---------- */
.page-about .flow {
  list-style: none;
  margin: 1.4rem 0 0;
  padding: 0;
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 0.7rem;
}

.page-about .flow-step {
  min-width: 0;
  padding: 0.95rem 1rem 1rem;
  background: var(--panel-2);
  border: 1px solid var(--line);
  border-left: 2px solid var(--blue);
  border-radius: 0 var(--radius-md) var(--radius-md) 0;
}

.page-about .flow-num {
  display: block;
  margin-bottom: 0.4rem;
  font-size: 0.7rem;
  letter-spacing: 0.12em;
  color: var(--blue);
}

.page-about .flow-title {
  margin: 0 0 0.35rem;
  font-family: var(--font-display);
  font-size: 1rem;
  letter-spacing: 0.04em;
  color: var(--ink);
}

.page-about .flow-step p {
  margin: 0;
  font-size: 0.87rem;
  line-height: 1.67;
  color: var(--muted);
}

/* ---------- 图片 ---------- */
.page-about .about-figure {
  margin: 1.5rem 0 0;
  border: 1px solid var(--line);
  border-radius: var(--radius-lg);
  overflow: hidden;
  background: var(--panel);
}

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

.page-about .figure-caption {
  margin: 0.65rem 0 0;
  font-family: var(--font-mono);
  font-size: 0.74rem;
  line-height: 1.6;
  letter-spacing: 0.02em;
  color: var(--muted);
}

/* ---------- 时间线 ---------- */
.page-about .timeline {
  list-style: none;
  position: relative;
  margin: 1.4rem 0 0;
  padding: 0 0 0 1.5rem;
}

.page-about .timeline::before {
  content: "";
  position: absolute;
  left: 4px;
  top: 0.55rem;
  bottom: 0.55rem;
  width: 1px;
  background: linear-gradient(to bottom, var(--green), var(--blue) 58%, var(--line));
}

.page-about .timeline-item {
  position: relative;
  padding-bottom: 1.45rem;
}

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

.page-about .timeline-item::before {
  content: "";
  position: absolute;
  left: -1.5rem;
  top: 0.42rem;
  width: 9px;
  height: 9px;
  border-radius: 50%;
  background: var(--bg);
  border: 1px solid var(--green);
}

.page-about .timeline-item:nth-child(3)::before {
  border-color: var(--blue);
}

.page-about .timeline-phase {
  display: block;
  margin-bottom: 0.3rem;
  font-size: 0.7rem;
  letter-spacing: 0.12em;
  color: var(--green);
}

.page-about .timeline-item:nth-child(3) .timeline-phase {
  color: var(--blue);
}

.page-about .timeline-title {
  margin: 0 0 0.35rem;
  font-family: var(--font-display);
  font-size: 1.05rem;
  letter-spacing: 0.03em;
  color: var(--ink);
  transition: color var(--dur);
}

.page-about .timeline-item:hover .timeline-title {
  color: var(--green);
}

.page-about .timeline-item p {
  margin: 0;
  max-width: 62ch;
  font-size: 0.9rem;
  line-height: 1.72;
  color: var(--muted);
}

/* ---------- 团队比例条 ---------- */
.page-about .ratio {
  display: grid;
  gap: 0.9rem;
  margin: 1.3rem 0 1.2rem;
  padding: 1.05rem 1rem;
  background: var(--panel);
  border: 1px solid var(--line);
  border-radius: var(--radius-md);
}

.page-about .ratio-row {
  display: grid;
  grid-template-columns: minmax(0, 1fr) auto;
  align-items: center;
  gap: 0.4rem 0.75rem;
}

.page-about .ratio-label {
  font-size: 0.88rem;
  color: var(--ink);
  min-width: 0;
}

.page-about .ratio-value {
  font-family: var(--font-mono);
  font-size: 0.8rem;
  font-variant-numeric: tabular-nums;
  color: var(--muted);
}

.page-about .ratio-track {
  grid-column: 1 / -1;
  display: block;
  height: 8px;
  border-radius: var(--radius-pill);
  background: var(--bg);
  border: 1px solid var(--line);
  overflow: hidden;
}

.page-about .ratio-fill {
  display: block;
  height: 100%;
  border-radius: var(--radius-pill);
}

.page-about .ratio-fill--core {
  width: 39%;
  background: var(--green);
}

.page-about .ratio-fill--rest {
  width: 61%;
  background: var(--blue);
}

.page-about .partners {
  list-style: none;
  margin: 0;
  padding: 0;
  display: flex;
  flex-wrap: wrap;
  gap: 0.6rem;
}

.page-about .partners li {
  display: inline-flex;
  align-items: baseline;
  gap: 0.4rem;
  padding: 0.4rem 0.85rem;
  border: 1px solid var(--line);
  border-radius: var(--radius-pill);
  background: var(--panel-2);
}

.page-about .partners-num {
  font-size: 1rem;
  color: var(--green);
  font-variant-numeric: tabular-nums;
}

.page-about .partners-label {
  font-size: 0.8rem;
  color: var(--muted);
}

/* ---------- 服务范围 ---------- */
.page-about .reach {
  list-style: none;
  margin: 1.3rem 0 0;
  padding: 0;
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 1px;
  background: var(--line);
  border: 1px solid var(--line);
  border-radius: var(--radius-md);
  overflow: hidden;
}

.page-about .reach-item {
  display: flex;
  flex-direction: column;
  gap: 0.3rem;
  min-width: 0;
  padding: 1rem;
  background: var(--panel);
}

.page-about .reach-num {
  font-size: clamp(1.5rem, 4.6vw, 2rem);
  line-height: 1;
  color: var(--ink);
  font-variant-numeric: tabular-nums;
}

.page-about .reach-num em {
  font-style: normal;
  font-size: 0.5em;
  margin-left: 0.08em;
  color: var(--green);
}

.page-about .reach-label {
  font-size: 0.78rem;
  letter-spacing: 0.03em;
  color: var(--muted);
}

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

.page-about .rhythm-row {
  display: flex;
  flex-wrap: wrap;
  align-items: baseline;
  justify-content: space-between;
  gap: 0.35rem 1rem;
  padding: 0.8rem 0;
  border-bottom: 1px solid var(--line);
}

.page-about .rhythm-key {
  font-size: 0.9rem;
  color: var(--ink);
}

.page-about .rhythm-val {
  font-size: 0.88rem;
  color: var(--blue);
  font-variant-numeric: tabular-nums;
}

/* ---------- 选择理由 ---------- */
.page-about .why {
  list-style: none;
  margin: 0;
  padding: 0;
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 0.75rem;
}

.page-about .why-item {
  position: relative;
  min-width: 0;
  padding: 1.1rem 1rem 1.15rem;
  background: linear-gradient(160deg, var(--panel-2), var(--panel));
  border: 1px solid var(--line);
  border-radius: var(--radius-lg);
}

.page-about .why-num {
  display: block;
  margin-bottom: 0.45rem;
  font-size: 0.7rem;
  letter-spacing: 0.14em;
  color: var(--orange);
}

.page-about .why-heading {
  margin: 0 0 0.45rem;
  font-family: var(--font-display);
  font-size: 1.05rem;
  letter-spacing: 0.04em;
  color: var(--ink);
}

.page-about .why-item p {
  margin: 0;
  font-size: 0.89rem;
  line-height: 1.72;
  color: var(--muted);
}

.page-about .about-cta {
  display: flex;
  flex-wrap: wrap;
  gap: 0.65rem;
  margin-top: 1.5rem;
}

.page-about .about-cta .btn {
  min-height: 44px;
  padding-inline: 1.35rem;
}

/* ---------- 响应式 ---------- */
@media (min-width: 30rem) {
  .page-about .about-facts {
    grid-template-columns: repeat(4, minmax(0, 1fr));
  }
}

@media (min-width: 48rem) {
  .page-about .lineup {
    grid-template-columns: repeat(3, minmax(0, 1fr));
  }

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

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

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

@media (min-width: 56rem) {
  .page-about .flow {
    grid-template-columns: repeat(4, minmax(0, 1fr));
  }
}

@media (min-width: 62rem) {
  .page-about .about-body {
    grid-template-columns: 200px minmax(0, 1fr);
    gap: clamp(2rem, 4vw, 3.6rem);
  }

  .page-about .about-index {
    position: sticky;
    top: calc(var(--header-h) + 1.25rem);
    align-self: start;
  }

  .page-about .about-index-list {
    flex-direction: column;
    gap: 0;
    overflow-x: visible;
    padding-bottom: 0;
    border-left: 1px solid var(--line);
  }

  .page-about .about-index-list li {
    flex: 0 0 auto;
  }

  .page-about .about-index-link {
    position: relative;
    display: flex;
    border: 0;
    border-radius: 0;
    padding: 0.55rem 0 0.55rem 0.85rem;
    background: transparent;
    font-size: 0.88rem;
    white-space: normal;
  }

  .page-about .about-index-link::before {
    content: "";
    position: absolute;
    left: -1px;
    top: 0;
    bottom: 0;
    width: 2px;
    background: transparent;
    transition: background-color var(--dur);
  }

  .page-about .about-index-link:hover,
  .page-about .about-index-link:focus-visible {
    background: transparent;
    color: var(--ink);
  }

  .page-about .about-index-link:hover::before,
  .page-about .about-index-link:focus-visible::before {
    background: var(--green);
  }
}

@media (prefers-reduced-motion: reduce) {
  .page-about .lineup-item,
  .page-about .timeline-title,
  .page-about .about-index-link,
  .page-about .about-index-link::before {
    transition: none;
  }
}