.page-about {
  overflow-x: clip;
  --about-text-soft: #3A4A5C;
  --about-line-tint: rgba(30, 111, 186, 0.28);
}

/* ===== 首屏框景 ===== */
.page-about .about-hero {
  background: linear-gradient(135deg, var(--grass-blue) 0%, var(--grass-blue-dark) 100%);
  color: var(--white);
  padding: 32px 0 48px;
}

.page-about .about-hero .breadcrumbs {
  color: rgba(255, 255, 255, 0.68);
  margin-bottom: 4px;
}

.page-about .about-hero .breadcrumbs a {
  color: rgba(255, 255, 255, 0.86);
  text-decoration: none;
  transition: color 0.3s ease;
}

.page-about .about-hero .breadcrumbs a:hover {
  color: var(--sunset-orange);
}

.page-about .about-hero .crumb-sep {
  margin: 0 6px;
  opacity: 0.55;
}

.page-about .about-hero .crumb-current {
  color: var(--white);
  font-weight: 600;
}

.page-about .about-hero-frame {
  position: relative;
  margin-top: 20px;
  padding: 28px 20px 32px;
  border: 1px solid rgba(255, 255, 255, 0.42);
  background: rgba(255, 255, 255, 0.07);
}

.page-about .about-corner {
  position: absolute;
  width: 18px;
  height: 18px;
  border-color: var(--sunset-orange);
  border-style: solid;
  pointer-events: none;
}

.page-about .about-corner--tl { top: -1px; left: -1px; border-width: 3px 0 0 3px; }
.page-about .about-corner--tr { top: -1px; right: -1px; border-width: 3px 3px 0 0; }
.page-about .about-corner--bl { bottom: -1px; left: -1px; border-width: 0 0 3px 3px; }
.page-about .about-corner--br { bottom: -1px; right: -1px; border-width: 0 3px 3px 0; }

.page-about .about-hero-kicker {
  font-family: var(--font-display);
  letter-spacing: 0.08em;
  font-size: 0.8rem;
  color: var(--sunset-orange);
  margin-bottom: 12px;
  text-transform: uppercase;
}

.page-about .about-hero h1 {
  font-family: var(--font-display);
  font-size: clamp(1.8rem, 5vw, 2.8rem);
  line-height: 1.25;
  margin-bottom: 16px;
  font-weight: 700;
}

.page-about .about-hero-desc {
  font-size: 1rem;
  line-height: 1.75;
  color: rgba(255, 255, 255, 0.9);
  max-width: 56rem;
  margin-bottom: 20px;
}

.page-about .about-hero-meta {
  display: flex;
  flex-wrap: wrap;
  gap: 8px 14px;
  margin-bottom: 24px;
}

.page-about .about-hero-meta span {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  border: 1px solid rgba(255, 255, 255, 0.3);
  border-radius: 999px;
  padding: 4px 14px;
  font-size: 0.85rem;
}

.page-about .about-hero-meta span::before {
  content: "";
  width: 6px;
  height: 6px;
  border-radius: 50%;
  background: var(--sunset-orange);
}

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

.page-about .about-hero .btn-primary {
  background: var(--white);
  color: var(--grass-blue);
  border-color: var(--white);
}

.page-about .about-hero .btn-primary:hover {
  background: var(--sunset-orange);
  border-color: var(--sunset-orange);
  color: var(--white);
}

.page-about .about-hero .btn-outline {
  border-color: rgba(255, 255, 255, 0.6);
  color: var(--white);
}

.page-about .about-hero .btn-outline:hover {
  border-color: var(--sunset-orange);
  color: var(--sunset-orange);
}

/* ===== 品牌故事 ===== */
.page-about .about-story {
  padding: 48px 0;
  background: var(--paper-warm);
}

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

.page-about .about-story-copy .section-head {
  margin-bottom: 20px;
}

.page-about .about-paper-stack {
  display: grid;
  grid-template-columns: 1fr;
  margin-top: 12px;
}

.page-about .about-story-paper {
  grid-area: 1 / 1;
  background: var(--white);
  border: 1px solid var(--dune-gold);
  border-radius: 2px;
  padding: 24px;
  box-shadow: var(--shadow-card);
}

.page-about .about-story-paper--back {
  margin: 14px 0 0 22px;
  transform: rotate(1deg);
  z-index: 0;
}

.page-about .about-story-paper--back p {
  color: var(--about-text-soft);
  line-height: 1.65;
  font-size: 0.92rem;
  margin-bottom: 12px;
}

.page-about .about-story-paper--front {
  z-index: 1;
  margin: 0 10px 0 0;
  transform: rotate(-0.3deg);
}

.page-about .about-story-paper--front p + p {
  margin-top: 12px;
}

.page-about .about-story-paper--front p {
  line-height: 1.75;
  color: var(--ink-core);
}

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

.page-about .about-story-img {
  width: 100%;
  height: auto;
  border-radius: var(--radius);
  box-shadow: var(--shadow-hover);
  display: block;
}

.page-about .about-story-media figcaption {
  margin-top: 12px;
  font-size: 0.85rem;
  color: var(--about-text-soft);
  text-align: right;
  letter-spacing: 0.05em;
  padding-right: 4px;
}

/* ===== 发展里程碑 ===== */
.page-about .about-milestones {
  padding: 48px 0;
  background: var(--cloud-white);
}

.page-about .about-milestones-head {
  margin-bottom: 36px;
}

.page-about .steppe-diamonds {
  margin: 14px 0;
}

.page-about .about-timeline {
  position: relative;
  padding-left: 28px;
}

.page-about .about-timeline::before {
  content: "";
  position: absolute;
  left: 8px;
  top: 6px;
  bottom: 6px;
  width: 2px;
  background: linear-gradient(to bottom, var(--grass-blue) 0%, var(--dune-gold) 55%, var(--sunset-orange) 100%);
  border-radius: 2px;
}

.page-about .about-timeline-item {
  position: relative;
  margin-bottom: 20px;
}

.page-about .about-timeline-marker {
  position: absolute;
  left: -30px;
  top: 18px;
  width: 16px;
  height: 16px;
  border-radius: 50%;
  background: var(--cloud-white);
  border: 3px solid var(--grass-blue);
  z-index: 1;
}

.page-about .about-timeline-marker span {
  display: none;
}

.page-about .about-timeline-card {
  position: relative;
  background: var(--white);
  border: 1px solid var(--mist-gray);
  border-left: 4px solid var(--grass-blue);
  border-radius: 0 var(--radius) var(--radius) 0;
  box-shadow: var(--shadow-card);
  transition: border-color 0.3s ease, box-shadow 0.3s ease;
}

.page-about .about-timeline-card::before {
  content: "";
  position: absolute;
  top: -1px;
  left: -1px;
  width: 46px;
  height: 8px;
  background: var(--sunset-orange);
  border-radius: 0 0 8px 0;
  opacity: 0.85;
}

.page-about .about-timeline-card:hover {
  border-color: var(--dune-gold);
  box-shadow: var(--shadow-hover);
}

.page-about .about-timeline-toggle {
  display: flex;
  align-items: baseline;
  gap: 12px;
  width: 100%;
  background: none;
  border: none;
  padding: 18px 16px 10px;
  cursor: pointer;
  text-align: left;
  font-family: var(--font-body);
}

.page-about .about-timeline-phase {
  flex-shrink: 0;
  font-family: var(--font-display);
  font-size: 0.78rem;
  letter-spacing: 0.07em;
  color: var(--grass-blue);
  text-transform: uppercase;
}

.page-about .about-timeline-title {
  flex: 1;
  font-weight: 600;
  font-size: 1rem;
  color: var(--ink-core);
  line-height: 1.4;
}

.page-about .accordion-arrow {
  flex-shrink: 0;
  color: var(--sunset-orange);
  font-size: 1.2rem;
  transition: transform 0.35s ease;
  align-self: center;
}

.page-about .about-timeline-item.is-open .accordion-arrow {
  transform: rotate(90deg);
}

.page-about .about-timeline-panel {
  padding: 0 16px 16px;
}

.page-about .about-timeline-inner {
  border-top: 1px dashed var(--mist-gray);
  padding-top: 12px;
  color: var(--about-text-soft);
  line-height: 1.7;
  font-size: 0.94rem;
}

.page-about .about-milestone-photo {
  margin: 40px 0 0;
}

.page-about .about-milestone-img {
  width: 100%;
  height: auto;
  max-height: 400px;
  object-fit: cover;
  border-radius: var(--radius);
  box-shadow: var(--shadow-card);
  display: block;
}

.page-about .about-milestone-photo figcaption {
  margin-top: 12px;
  font-size: 0.85rem;
  color: var(--about-text-soft);
  text-align: right;
  padding-right: 6px;
  letter-spacing: 0.04em;
}

/* ===== 资质与认证 ===== */
.page-about .about-credentials {
  padding: 48px 0;
  background: linear-gradient(180deg, var(--paper-warm) 0%, var(--cloud-white) 100%);
}

.page-about .about-credential-grid {
  display: grid;
  gap: 16px;
  margin-top: 28px;
}

.page-about .about-credential {
  background: var(--white);
  border: 1px solid var(--mist-gray);
  border-top: 4px solid var(--grass-blue);
  border-radius: 0 0 var(--radius) var(--radius);
  padding: 24px;
  box-shadow: var(--shadow-card);
  transition: transform 0.3s ease, box-shadow 0.3s ease;
}

.page-about .about-credential:hover {
  transform: translateY(-3px);
  box-shadow: var(--shadow-hover);
}

.page-about .about-credential-num {
  display: inline-block;
  font-family: var(--font-display);
  font-size: 0.78rem;
  letter-spacing: 0.12em;
  color: var(--sunset-orange);
  margin-bottom: 10px;
}

.page-about .about-credential h3 {
  font-family: var(--font-display);
  font-size: 1.15rem;
  margin: 0 0 10px;
  color: var(--ink-core);
}

.page-about .about-credential p {
  color: var(--about-text-soft);
  line-height: 1.65;
  font-size: 0.94rem;
  margin: 0;
}

/* ===== 合作生态 ===== */
.page-about .about-ecosystem {
  padding: 48px 0;
  background: var(--cloud-white);
}

.page-about .about-eco-grid {
  display: grid;
  gap: 28px;
  margin-top: 28px;
}

.page-about .about-eco-visual {
  margin: 0;
}

.page-about .about-eco-img {
  width: 100%;
  height: auto;
  border-radius: var(--radius);
  box-shadow: var(--shadow-hover);
  display: block;
}

.page-about .about-eco-caption {
  margin-top: 12px;
  font-size: 0.85rem;
  color: var(--about-text-soft);
  text-align: center;
  letter-spacing: 0.04em;
}

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

.page-about .about-eco-node {
  background: var(--white);
  border: 1px solid var(--mist-gray);
  border-radius: var(--radius);
  padding: 20px;
  box-shadow: 0 2px 8px rgba(16, 42, 67, 0.05);
  transition: transform 0.3s ease, box-shadow 0.3s ease, border-color 0.3s ease;
}

.page-about .about-eco-node:hover,
.page-about .about-eco-node:focus-within {
  transform: translateY(-2px);
  border-color: var(--grass-blue);
  box-shadow: var(--shadow-hover);
}

.page-about .about-eco-node h3 {
  font-size: 1.05rem;
  margin: 0 0 8px;
  color: var(--ink-core);
  font-weight: 600;
}

.page-about .about-eco-node-desc {
  border-left: 3px solid var(--sunset-orange);
  padding-left: 12px;
}

.page-about .about-eco-node-desc p {
  color: var(--about-text-soft);
  line-height: 1.6;
  font-size: 0.92rem;
  margin: 0;
}

.page-about .about-eco-cta {
  margin-top: 36px;
  background: var(--grass-blue-soft);
  border: 1px solid var(--grass-blue);
  border-radius: var(--radius);
  padding: 24px 20px;
  text-align: center;
}

.page-about .about-eco-cta p {
  margin-bottom: 16px;
  color: var(--ink-core);
  font-weight: 500;
}

.page-about .about-eco-cta .btn {
  margin: 4px 6px;
}

/* ===== 桌面增强 ===== */
@media (min-width: 768px) {
  .page-about .about-hero {
    padding: 44px 0 72px;
  }

  .page-about .about-hero-frame {
    padding: 44px 48px 50px;
  }

  .page-about .about-story {
    padding: 72px 0;
  }

  .page-about .about-story-grid {
    grid-template-columns: 1.05fr 0.95fr;
    align-items: start;
    gap: 44px;
  }

  .page-about .about-story-media {
    margin-top: 12px;
  }

  .page-about .about-milestones {
    padding: 72px 0;
  }

  .page-about .about-timeline {
    max-width: 820px;
    padding-left: 72px;
    margin: 0 auto;
  }

  .page-about .about-timeline::before {
    left: 22px;
  }

  .page-about .about-timeline-marker {
    left: -64px;
    top: 12px;
    width: 46px;
    height: 46px;
    border-radius: 50%;
    background: var(--grass-blue);
    border: none;
    display: flex;
    align-items: center;
    justify-content: center;
    box-shadow: 0 4px 12px rgba(30, 111, 186, 0.3);
  }

  .page-about .about-timeline-marker span {
    display: inline-block;
    color: var(--white);
    font-family: var(--font-display);
    font-size: 1rem;
    font-weight: 700;
  }

  .page-about .about-credentials {
    padding: 72px 0;
  }

  .page-about .about-credential-grid {
    grid-template-columns: repeat(3, 1fr);
    gap: 20px;
  }

  .page-about .about-ecosystem {
    padding: 72px 0;
  }

  .page-about .about-eco-grid {
    grid-template-columns: 0.9fr 1.1fr;
    align-items: center;
    gap: 44px;
  }

  .page-about .about-eco-cta {
    padding: 32px;
  }
}

@media (min-width: 992px) {
  .page-about .about-timeline-card {
    transition-delay: 0s;
  }

  .page-about .about-milestone-photo {
    max-width: 960px;
    margin-left: auto;
    margin-right: auto;
  }
}