/* ===== 页面专属样式：.page-about ===== */
/* 移动端优先 — 基础样式为窄屏设计 */
.page-about {
  --about-gap: 2rem;
  --timeline-node-size: 20px;
  --timeline-line-width: 3px;
  display: block;
  width: 100%;
  max-width: 100%;
  padding: 0 1rem 3rem;
  color: var(--color-text-light);
  background: var(--color-bg);
}

/* ---------- 面包屑 ---------- */
.page-about .breadcrumb {
  padding: 1rem 0 0.5rem;
  font-family: var(--font-body);
  font-size: 0.875rem;
  color: rgba(255,255,255,0.6);
}
.page-about .breadcrumb ol {
  list-style: none;
  margin: 0;
  padding: 0;
  display: flex;
  flex-wrap: wrap;
  gap: 0.5rem;
}
.page-about .breadcrumb li + li::before {
  content: "/";
  margin-right: 0.5rem;
  color: rgba(255,255,255,0.3);
}
.page-about .breadcrumb a {
  color: var(--color-primary);
  text-decoration: none;
  transition: color 0.2s;
}
.page-about .breadcrumb a:hover {
  color: var(--color-secondary);
}
.page-about .breadcrumb [aria-current="page"] {
  color: var(--color-accent);
  font-weight: 600;
}

/* ---------- 首屏：品牌使命 ---------- */
.page-about .about-intro {
  display: flex;
  flex-direction: column;
  gap: var(--about-gap);
  padding: 2rem 0 3rem;
  align-items: center;
}
.page-about .intro-text {
  flex: 1 1 100%;
}
.page-about #intro-title {
  font-family: var(--font-heading);
  font-size: 2.8rem;
  line-height: 1.05;
  color: var(--color-primary);
  margin: 0 0 1rem;
  text-transform: uppercase;
  letter-spacing: -0.02em;
}
.page-about .intro-sub {
  font-family: var(--font-body);
  font-size: 1.125rem;
  line-height: 1.6;
  color: rgba(255,255,255,0.85);
  margin: 0 0 1.5rem;
  max-width: 35em;
}
.page-about .intro-tags {
  display: flex;
  flex-wrap: wrap;
  gap: 0.75rem;
}
.page-about .intro-tags .badge {
  display: inline-block;
  background: var(--color-card-bg);
  color: var(--color-accent);
  border: 1px solid rgba(255,215,0,0.4);
  padding: 0.35rem 1rem;
  border-radius: 2rem;
  font-family: var(--font-body);
  font-size: 0.875rem;
  font-weight: 600;
  letter-spacing: 0.02em;
}
.page-about .intro-visual {
  flex: 0 0 auto;
  width: 100%;
  max-width: 400px;
}
.page-about .hero-img {
  display: block;
  width: 100%;
  height: auto;
  max-width: 100%;
  object-fit: contain;
  border-radius: 12px;
  box-shadow: 0 0 40px rgba(0,191,255,0.15);
}

/* ---------- 品牌使命详情 ---------- */
.page-about .about-mission {
  padding: 2.5rem 0;
  border-top: 1px solid var(--color-border);
}
.page-about .mission-content {
  display: flex;
  flex-direction: column;
  gap: 1.25rem;
  max-width: 48em;
}
.page-about .mission-content p {
  font-family: var(--font-body);
  font-size: 1rem;
  line-height: 1.7;
  color: rgba(255,255,255,0.85);
  margin: 0;
}

/* ---------- 核心服务 ---------- */
.page-about .about-services {
  padding: 2.5rem 0;
  position: relative;
}
.page-about .services-grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: 1.25rem;
  margin-bottom: 2rem;
}
.page-about .service-card {
  background: var(--color-card-bg);
  backdrop-filter: blur(6px);
  -webkit-backdrop-filter: blur(6px);
  border: 1px solid var(--color-border);
  border-radius: 12px;
  padding: 1.5rem 1.25rem;
  transition: transform 0.25s ease, box-shadow 0.25s ease;
}
.page-about .service-card:hover {
  transform: translateY(-4px);
  box-shadow: 0 12px 28px rgba(0,191,255,0.15);
}
.page-about .card-icon {
  width: 44px;
  height: 44px;
  display: flex;
  align-items: center;
  justify-content: center;
  border-radius: 50%;
  margin-bottom: 1rem;
  transition: transform 0.3s ease;
}
.page-about .service-card:hover .card-icon {
  transform: scale(1.12) rotate(4deg);
}
.page-about .card-icon--primary {
  color: var(--color-primary);
  background: rgba(0,191,255,0.12);
}
.page-about .card-icon--secondary {
  color: var(--color-secondary);
  background: rgba(255,69,0,0.12);
}
.page-about .card-icon--accent {
  color: var(--color-accent);
  background: rgba(255,215,0,0.12);
}
.page-about .card-icon svg {
  display: block;
}
.page-about .service-card .card-title {
  font-family: var(--font-heading);
  font-size: 1.25rem;
  color: var(--color-text-light);
  margin: 0 0 0.4rem;
  letter-spacing: 0.01em;
}
.page-about .service-card .card-body {
  font-family: var(--font-body);
  font-size: 0.9375rem;
  line-height: 1.5;
  color: rgba(255,255,255,0.7);
}
.page-about .services-bg-visual {
  position: relative;
  margin-top: 1.5rem;
  border-radius: 12px;
  overflow: hidden;
  opacity: 0.7;
}
.page-about .bg-visual-img {
  display: block;
  width: 100%;
  height: auto;
  max-width: 100%;
  object-fit: cover;
  border-radius: 12px;
}

/* ---------- 改版时间线 ---------- */
.page-about .about-timeline {
  padding: 2.5rem 0;
  border-top: 1px solid var(--color-border);
}
.page-about .timeline-intro {
  font-family: var(--font-body);
  font-size: 1rem;
  color: rgba(255,255,255,0.7);
  margin: -0.5rem 0 2rem;
  max-width: 32em;
}
.page-about .timeline-rail {
  position: relative;
  padding-left: 2.2rem;
}
.page-about .timeline-rail::before {
  content: "";
  position: absolute;
  left: 10px;
  top: 8px;
  bottom: 8px;
  width: var(--timeline-line-width);
  background: linear-gradient(180deg, var(--color-primary), var(--color-secondary));
  border-radius: 2px;
}
.page-about .timeline-node {
  position: relative;
  margin-bottom: 2rem;
}
.page-about .node-marker {
  position: absolute;
  left: -2.2rem;
  top: 0.45rem;
  width: var(--timeline-node-size);
  height: var(--timeline-node-size);
  border-radius: 50%;
  background: var(--color-secondary);
  border: 3px solid var(--color-bg);
  box-shadow: 0 0 0 3px var(--color-primary), 0 4px 12px rgba(255,69,0,0.3);
  z-index: 2;
}
.page-about .node-details {
  display: block;
  background: var(--color-card-bg);
  backdrop-filter: blur(4px);
  -webkit-backdrop-filter: blur(4px);
  border: 1px solid var(--color-border);
  border-radius: 10px;
  padding: 0.75rem 1rem;
  transition: background 0.2s;
}
.page-about .node-details[open] {
  background: rgba(26,26,46,0.95);
}
.page-about .node-summary {
  display: flex;
  flex-wrap: wrap;
  align-items: baseline;
  gap: 0.75rem;
  cursor: pointer;
  list-style: none;
  font-family: var(--font-body);
}
.page-about .node-summary::-webkit-details-marker {
  display: none;
}
.page-about .node-summary::before {
  content: "▶";
  display: inline-block;
  font-size: 0.7rem;
  color: var(--color-primary);
  margin-right: 0.3rem;
  transition: transform 0.25s;
}
.page-about .node-details[open] > .node-summary::before {
  transform: rotate(90deg);
}
.page-about .node-label {
  font-weight: 700;
  font-size: 1.05rem;
  color: var(--color-text-light);
  letter-spacing: 0.01em;
}
.page-about .node-meta {
  font-size: 0.8rem;
  color: var(--color-accent);
  background: rgba(255,215,0,0.12);
  padding: 0.15rem 0.6rem;
  border-radius: 1rem;
  font-weight: 600;
}
.page-about .node-content {
  padding: 0.75rem 0 0.25rem;
  font-family: var(--font-body);
  font-size: 0.9375rem;
  line-height: 1.6;
  color: rgba(255,255,255,0.75);
}
.page-about .node-content p {
  margin: 0;
}
.page-about .timeline-img-wrap {
  margin: 0.5rem 0 1.5rem;
  text-align: center;
}
.page-about .timeline-img {
  display: inline-block;
  width: 160px;
  height: auto;
  max-width: 100%;
  border-radius: 10px;
  border: 1px solid var(--color-border);
  object-fit: contain;
  background: var(--color-card-bg);
}

/* ---------- CTA 区域 ---------- */
.page-about .about-cta {
  padding: 2.5rem 0 1rem;
  border-top: 1px solid var(--color-border);
  text-align: center;
}
.page-about .about-cta p {
  font-family: var(--font-body);
  font-size: 1rem;
  color: rgba(255,255,255,0.7);
  margin: 0 0 1.5rem;
}
.page-about .cta-links {
  display: flex;
  flex-wrap: wrap;
  justify-content: center;
  gap: 1rem;
}
.page-about .cta-links .btn {
  min-width: 150px;
}

/* ===== 桌面端（≥768px） ===== */
@media (min-width: 768px) {
  .page-about {
    padding: 0 2rem 4rem;
  }
  .page-about .about-intro {
    flex-direction: row;
    align-items: center;
    gap: 3rem;
    padding: 3rem 0 4rem;
  }
  .page-about .intro-text {
    flex: 1 1 55%;
  }
  .page-about .intro-visual {
    flex: 0 1 40%;
    max-width: 500px;
  }
  .page-about #intro-title {
    font-size: 4rem;
  }
  .page-about .intro-sub {
    font-size: 1.25rem;
  }
  .page-about .services-grid {
    grid-template-columns: repeat(2, 1fr);
  }
  .page-about .timeline-rail {
    padding-left: 3rem;
  }
  .page-about .timeline-rail::before {
    left: 16px;
  }
  .page-about .node-marker {
    left: -3rem;
    width: 24px;
    height: 24px;
  }
  .page-about .node-details {
    padding: 1rem 1.5rem;
  }
  .page-about .node-label {
    font-size: 1.1rem;
  }
}

/* ===== 大桌面端（≥1024px） ===== */
@media (min-width: 1024px) {
  .page-about {
    max-width: var(--max-width);
    margin: 0 auto;
  }
  .page-about .services-grid {
    grid-template-columns: repeat(3, 1fr);
  }
  .page-about .timeline-img {
    width: 200px;
  }
}