.page-about {
  --about-grid-faint: rgba(26, 42, 58, 0.05);
}

.page-about .container {
  max-width: 1280px;
  margin-inline: auto;
}

/* ---------- 首屏 Hero ---------- */
.page-about .about-hero {
  position: relative;
  overflow: hidden;
  padding: 28px 20px 40px;
  border-bottom: 1px solid var(--line);
  background:
    linear-gradient(var(--about-grid-faint) 1px, transparent 1px),
    linear-gradient(90deg, var(--about-grid-faint) 1px, transparent 1px);
  background-size: 28px 28px;
}

.page-about .about-hero-mark {
  position: absolute;
  right: -12px;
  bottom: -14px;
  margin: 0;
  font-family: var(--font-data);
  font-size: 96px;
  font-weight: 700;
  line-height: 1;
  color: rgba(26, 42, 58, 0.07);
  pointer-events: none;
  z-index: 0;
}

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

.page-about .breadcrumb {
  margin-bottom: 28px;
}

.page-about .about-hero-grid {
  display: grid;
  gap: 32px;
}

.page-about .about-hero h1 {
  font-size: 32px;
  line-height: 1.12;
  letter-spacing: -0.02em;
  margin: 0 0 14px;
  max-width: 12em;
}

.page-about .about-hero .lede {
  font-size: 15px;
  line-height: 1.7;
  color: var(--text-muted);
  max-width: 32em;
  margin: 0;
}

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

.page-about .about-metrics {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 12px;
  margin: 0;
  padding: 0;
  list-style: none;
}

.page-about .about-metric {
  border: 1px solid var(--line);
  background: rgba(255, 255, 255, 0.72);
  padding: 16px 14px;
}

.page-about .about-metric dt {
  font-size: 11px;
  font-weight: 600;
  letter-spacing: 0.1em;
  text-transform: uppercase;
  color: var(--text-muted);
}

.page-about .about-metric-num {
  display: block;
  margin: 6px 0 0;
  font-family: var(--font-data);
  font-size: 30px;
  font-weight: 700;
  line-height: 1;
  color: var(--bg-deep);
  letter-spacing: -0.01em;
}

.page-about .about-metric-label {
  display: block;
  margin-top: 6px;
  font-size: 12px;
  color: var(--text-muted);
}

/* ---------- 品牌故事 ---------- */
.page-about .about-story {
  padding: 48px 20px;
}

.page-about .about-story-grid {
  display: grid;
  gap: 28px;
  align-items: center;
}

.page-about .about-story-copy p {
  margin: 0 0 14px;
  font-size: 15px;
  line-height: 1.7;
  color: var(--text-muted);
}

.page-about .about-story-copy .btn {
  margin-top: 8px;
}

.page-about .about-story-media {
  margin: 0;
  border: 1px solid var(--line);
  background: var(--white);
  padding: 8px;
}

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

.page-about .about-story-media figcaption {
  margin-top: 8px;
  font-family: var(--font-data);
  font-size: 12px;
  color: var(--text-muted);
}

/* ---------- 里程碑时间线 ---------- */
.page-about .about-timeline {
  padding: 48px 20px;
  background: var(--bg-deep);
  color: var(--white);
  position: relative;
}

.page-about .about-timeline::before {
  content: "";
  position: absolute;
  inset: 0;
  background:
    linear-gradient(rgba(255, 255, 255, 0.04) 1px, transparent 1px),
    linear-gradient(90deg, rgba(255, 255, 255, 0.04) 1px, transparent 1px);
  background-size: 24px 24px;
  pointer-events: none;
}

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

.page-about .about-timeline-head .eyebrow {
  color: var(--volt);
}

.page-about .about-timeline-head h2,
.page-about .about-principles-head h2,
.page-about .about-credentials-head h2 {
  margin: 4px 0 10px;
  font-size: 28px;
  letter-spacing: -0.02em;
  line-height: 1.2;
}

.page-about .about-timeline-head .section-lede {
  color: rgba(255, 255, 255, 0.7);
  font-size: 15px;
  line-height: 1.6;
  max-width: 30em;
  margin: 0;
}

.page-about .about-timeline-grid {
  margin-top: 36px;
  display: grid;
  gap: 32px;
}

.page-about .about-timeline-art {
  display: none;
}

.page-about .timeline-list {
  list-style: none;
  margin: 0;
  padding: 0;
  position: relative;
}

.page-about .timeline-list::before {
  content: "";
  position: absolute;
  left: 5px;
  top: 6px;
  bottom: 6px;
  width: 2px;
  background: linear-gradient(180deg, var(--moss) 0%, var(--volt) 100%);
  opacity: 0.45;
}

.page-about .timeline-item {
  position: relative;
  padding: 0 0 36px 30px;
}

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

.page-about .timeline-node {
  position: absolute;
  left: 0;
  top: 4px;
  width: 12px;
  height: 12px;
  border-radius: 50%;
  background: var(--bg-deep);
  border: 2px solid var(--volt);
  box-shadow: 0 0 0 4px rgba(198, 255, 0, 0.14);
  transition: background 0.2s ease, box-shadow 0.2s ease;
}

.page-about .timeline-item:hover .timeline-node {
  background: var(--volt);
  box-shadow: 0 0 0 8px rgba(198, 255, 0, 0.22);
}

.page-about .timeline-card {
  background: rgba(255, 255, 255, 0.05);
  border: 1px solid rgba(255, 255, 255, 0.1);
  border-left: 3px solid var(--moss);
  padding: 16px 18px;
  transition: background 0.2s ease, transform 0.2s ease;
}

.page-about .timeline-item:hover .timeline-card {
  background: rgba(255, 255, 255, 0.08);
  transform: translateX(2px);
}

.page-about .timeline-year {
  margin: 0 0 4px;
  font-family: var(--font-data);
  font-size: 14px;
  font-weight: 700;
  letter-spacing: 0.06em;
  color: var(--volt);
}

.page-about .timeline-card h3 {
  margin: 0 0 6px;
  font-size: 16px;
  line-height: 1.4;
  color: var(--white);
}

.page-about .timeline-card p {
  margin: 0;
  font-size: 14px;
  line-height: 1.65;
  color: rgba(255, 255, 255, 0.72);
}

/* ---------- 数据原则 ---------- */
.page-about .about-principles {
  padding: 48px 20px;
}

.page-about .section-lede {
  margin: 0;
  font-size: 15px;
  line-height: 1.6;
  color: var(--text-muted);
  max-width: 28em;
}

.page-about .principle-grid {
  margin-top: 32px;
  display: grid;
  gap: 16px;
}

.page-about .principle-card {
  position: relative;
  background: var(--white);
  border: 1px solid var(--line);
  border-top: 3px solid var(--moss);
  padding: 22px 20px;
  transition: transform 0.2s ease, box-shadow 0.2s ease;
}

.page-about .principle-card:hover {
  transform: translate(-2px, -2px);
  box-shadow: var(--shadow-card);
}

.page-about .principle-num {
  margin: 0 0 10px;
  font-family: var(--font-data);
  font-size: 44px;
  font-weight: 700;
  line-height: 1;
  color: var(--moss);
}

.page-about .principle-card h3 {
  margin: 0 0 8px;
  font-size: 17px;
  letter-spacing: -0.01em;
}

.page-about .principle-card p {
  margin: 0;
  font-size: 14px;
  line-height: 1.7;
  color: var(--text-muted);
}

/* ---------- 资质与合作伙伴 ---------- */
.page-about .about-credentials {
  padding: 48px 20px;
  border-top: 1px solid var(--line);
  background:
    linear-gradient(var(--about-grid-faint) 1px, transparent 1px),
    linear-gradient(90deg, var(--about-grid-faint) 1px, transparent 1px);
  background-size: 32px 32px;
}

.page-about .about-credentials-head .section-lede {
  margin-bottom: 0;
}

.page-about .credentials-grid {
  margin-top: 32px;
  display: grid;
  gap: 28px;
  align-items: start;
}

.page-about .credential-list {
  display: grid;
  gap: 12px;
}

.page-about .credential-item {
  display: flex;
  gap: 14px;
  align-items: flex-start;
  padding: 16px;
  background: rgba(255, 255, 255, 0.78);
  border: 1px solid var(--line);
  border-left: 3px solid var(--clay);
}

.page-about .credential-item h3 {
  margin: 0 0 4px;
  font-size: 15px;
}

.page-about .credential-item p {
  margin: 0;
  font-size: 13px;
  line-height: 1.65;
  color: var(--text-muted);
}

.page-about .credential-icon {
  font-size: 22px;
  line-height: 1;
  color: var(--clay);
}

.page-about .credential-media {
  margin: 0;
}

.page-about .credential-media img {
  display: block;
  width: 100%;
  max-width: 100%;
  height: auto;
  border: 1px solid var(--line);
}

.page-about .credential-media figcaption {
  margin-top: 8px;
  font-family: var(--font-data);
  font-size: 12px;
  color: var(--text-muted);
}

.page-about .partner-section {
  margin-top: 40px;
  padding-top: 32px;
  border-top: 1px solid var(--line);
}

.page-about .partner-section h3 {
  font-size: 20px;
  margin: 0 0 6px;
}

.page-about .partner-section > p {
  margin: 0 0 20px;
  font-size: 14px;
  color: var(--text-muted);
  max-width: 32em;
}

.page-about .partner-grid {
  display: grid;
  gap: 12px;
}

.page-about .partner-grid .fold {
  background: rgba(255, 255, 255, 0.85);
  border: 1px solid var(--line);
}

.page-about .partner-grid summary {
  display: flex;
  align-items: center;
  gap: 12px;
  padding: 14px 16px;
  cursor: pointer;
  list-style: none;
  font-size: 15px;
  font-weight: 700;
  user-select: none;
}

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

.page-about .partner-mark {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 38px;
  height: 38px;
  flex: 0 0 38px;
  font-family: var(--font-data);
  font-size: 13px;
  font-weight: 700;
  color: var(--volt);
  background: var(--bg-deep);
}

.page-about .partner-grid .fold-body {
  padding: 0 16px 16px 66px;
  font-size: 13px;
  line-height: 1.65;
  color: var(--text-muted);
}

.page-about .partner-grid .fold-body p {
  margin: 0;
}

/* ---------- 团队规模 ---------- */
.page-about .about-team {
  padding: 48px 20px;
  background: var(--bg-deep);
  color: var(--white);
}

.page-about .about-team .eyebrow {
  color: var(--volt);
}

.page-about .about-team h2 {
  margin: 4px 0 26px;
  font-size: 28px;
  letter-spacing: -0.02em;
  line-height: 1.2;
}

.page-about .team-grid {
  display: grid;
  gap: 14px;
}

.page-about .team-stat {
  padding: 20px 16px;
  text-align: center;
  background: rgba(255, 255, 255, 0.05);
  border: 1px solid rgba(255, 255, 255, 0.12);
}

.page-about .team-num {
  margin: 0;
  font-family: var(--font-data);
  font-size: 40px;
  font-weight: 700;
  line-height: 1.1;
  color: var(--volt);
}

.page-about .team-label {
  margin: 8px 0 0;
  font-size: 14px;
  color: rgba(255, 255, 255, 0.72);
}

.page-about .about-team-note {
  margin: 24px 0 0;
  font-size: 15px;
  line-height: 1.7;
  color: rgba(255, 255, 255, 0.72);
  max-width: 32em;
}

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

.page-about .about-team .btn-ghost {
  border-color: rgba(255, 255, 255, 0.45);
  color: var(--white);
}

.page-about .about-team .btn-data {
  background: var(--volt);
  border-color: var(--volt);
  color: var(--bg-deep);
}

/* ---------- 桌面端 ---------- */
@media (min-width: 1024px) {
  .page-about .about-hero {
    padding: 56px 40px 64px;
  }

  .page-about .about-hero-grid {
    grid-template-columns: minmax(0, 1.05fr) minmax(0, 0.95fr);
    gap: 56px;
    align-items: center;
  }

  .page-about .about-hero h1 {
    font-size: 48px;
  }

  .page-about .about-hero .lede {
    font-size: 17px;
  }

  .page-about .about-hero-mark {
    font-size: 180px;
    right: 20px;
    bottom: -30px;
  }

  .page-about .about-metrics {
    gap: 14px;
  }

  .page-about .about-metric {
    padding: 20px 18px;
  }

  .page-about .about-metric-num {
    font-size: 38px;
  }

  .page-about .about-story {
    padding: 80px 40px;
  }

  .page-about .about-story-grid {
    grid-template-columns: minmax(0, 1fr) minmax(0, 1.05fr);
    gap: 56px;
  }

  .page-about .about-story-copy p {
    font-size: 16px;
  }

  .page-about .about-timeline {
    padding: 80px 40px;
  }

  .page-about .about-timeline-grid {
    grid-template-columns: 260px minmax(0, 1fr);
    gap: 56px;
  }

  .page-about .about-timeline-art {
    display: block;
    position: sticky;
    top: 32px;
    align-self: start;
    margin: 0;
  }

  .page-about .about-timeline-art img {
    display: block;
    width: 100%;
    max-width: 100%;
    height: auto;
    opacity: 0.72;
    border: 1px solid rgba(255, 255, 255, 0.14);
  }

  .page-about .about-timeline-art-caption {
    margin: 10px 0 0;
    font-family: var(--font-data);
    font-size: 12px;
    letter-spacing: 0.06em;
    color: rgba(255, 255, 255, 0.5);
  }

  .page-about .timeline-card {
    padding: 20px 24px;
  }

  .page-about .timeline-card h3 {
    font-size: 18px;
  }

  .page-about .timeline-card p {
    font-size: 15px;
  }

  .page-about .about-principles {
    padding: 80px 40px;
  }

  .page-about .about-principles-head h2,
  .page-about .about-credentials-head h2,
  .page-about .about-team h2,
  .page-about .about-timeline-head h2 {
    font-size: 32px;
  }

  .page-about .principle-grid {
    grid-template-columns: repeat(3, 1fr);
    gap: 22px;
  }

  .page-about .principle-card {
    padding: 28px 24px;
  }

  .page-about .about-credentials {
    padding: 80px 40px;
  }

  .page-about .credentials-grid {
    grid-template-columns: minmax(0, 1fr) 320px;
    gap: 48px;
  }

  .page-about .credential-item {
    padding: 18px 20px;
  }

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

  .page-about .about-team {
    padding: 80px 40px;
  }

  .page-about .team-grid {
    grid-template-columns: repeat(3, 1fr);
    max-width: 720px;
  }
}