.page-about {
  --page-bg: var(--color-content-bg, #222222);
  --page-text: var(--color-light-gray, #E0E0E0);
  --page-heading: var(--color-warm-paper, #F5E6D3);
  --page-accent: var(--color-vibrant-orange, #FF6B35);
  --page-neon-from: var(--color-neon-blue, #00D4FF);
  --page-neon-to: var(--color-neon-green, #00FF87);
  --page-card-bg: var(--color-card-bg, #2A2A2A);
  --page-border: var(--color-border-subtle, rgba(255,255,255,0.08));
  --page-radius: var(--radius-sm, 2px);
  --page-section-gap: clamp(2.5rem, 6vw, 4.5rem);

  background-color: var(--page-bg);
  color: var(--page-text);
  padding-bottom: var(--space-3xl, 4rem);
}

/* ── 面包屑 ── */
.page-about .breadcrumb {
  padding: var(--space-md, 1rem) 0 var(--space-lg, 1.5rem) 0;
  font-size: var(--size-small, 0.875rem);
  color: var(--color-metallic-silver, #B0B0B0);
}
.page-about .breadcrumb ol {
  list-style: none;
  display: flex;
  flex-wrap: wrap;
  gap: 0.375rem 0.75rem;
  margin: 0;
  padding: 0;
}
.page-about .breadcrumb li {
  display: inline-flex;
  align-items: center;
  gap: 0.375rem;
}
.page-about .breadcrumb li + li::before {
  content: "/";
  color: var(--color-metallic-silver, #B0B0B0);
  opacity: 0.5;
}
.page-about .breadcrumb a {
  color: var(--color-metallic-silver, #B0B0B0);
  text-decoration: none;
  transition: color var(--transition-fast, 150ms ease);
}
.page-about .breadcrumb a:hover,
.page-about .breadcrumb a:focus-visible {
  color: var(--page-accent);
}
.page-about .breadcrumb [aria-current="page"] {
  color: var(--page-heading);
}

/* ── 通用 section 容器 ── */
.page-about__section {
  margin-bottom: var(--page-section-gap);
}

/* ── 品牌定位区 ── */
.page-about__brand {
  display: flex;
  flex-direction: column;
  gap: var(--space-xl, 2rem);
}
.page-about__brand-text {
  flex: 1 1 0%;
  min-width: 0;
}
.page-about__brand-text h1 {
  font-family: var(--font-headings);
  font-size: var(--size-h1);
  color: var(--page-heading);
  margin: 0 0 0.15em 0;
  line-height: 1.15;
  letter-spacing: -0.01em;
}
.page-about__subtitle {
  font-family: var(--font-headings);
  font-size: var(--size-h3);
  color: var(--page-accent);
  margin: 0 0 0.5em 0;
  font-weight: 400;
  position: relative;
  display: inline-block;
}
.page-about__subtitle::after {
  content: "";
  position: absolute;
  left: 0;
  bottom: -4px;
  width: 48px;
  height: 2px;
  background: linear-gradient(90deg, var(--page-neon-from), var(--page-neon-to));
  border-radius: 1px;
}
.page-about__brand-tagline {
  font-family: var(--font-headings);
  font-size: var(--size-h3);
  color: var(--color-metallic-silver, #B0B0B0);
  margin: var(--space-md, 1rem) 0 var(--space-lg, 1.5rem) 0;
  line-height: 1.3;
  font-style: italic;
}
.page-about__brand-text p:not(.page-about__brand-tagline) {
  font-size: var(--size-body);
  line-height: 1.7;
  margin: 0 0 var(--space-md, 1rem) 0;
  max-width: 640px;
}
.page-about__brand-image {
  flex: 0 0 auto;
  width: 100%;
  max-width: 600px;
  margin: 0 auto;
}
.page-about__brand-img {
  display: block;
  width: 100%;
  height: auto;
  max-width: 100%;
  border-radius: var(--radius-md, 4px);
  box-shadow: var(--shadow-card, 0 2px 8px rgba(0,0,0,0.3));
  background: var(--page-card-bg);
  object-fit: cover;
}

/* ── 核心服务区 ── */
.page-about__section-title {
  font-family: var(--font-headings);
  font-size: var(--size-h2);
  color: var(--page-heading);
  margin: 0 0 0.3em 0;
  line-height: 1.2;
}
.page-about__section-desc {
  font-size: var(--size-body);
  color: var(--color-metallic-silver, #B0B0B0);
  margin: 0 0 var(--space-xl, 2rem) 0;
  max-width: 540px;
}
.page-about__services-grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: var(--space-lg, 1.5rem);
  margin-bottom: var(--space-xl, 2rem);
}
.page-about__service-card {
  background: var(--page-card-bg);
  border: 1px solid var(--page-border);
  border-radius: var(--radius-md, 4px);
  padding: var(--space-lg, 1.5rem);
  box-shadow: var(--shadow-card, 0 2px 8px rgba(0,0,0,0.3));
  transition: border-color var(--transition-base, 300ms ease),
              box-shadow var(--transition-base, 300ms ease);
  cursor: default;
  position: relative;
}
.page-about__service-card:hover,
.page-about__service-card:focus-within {
  border-color: var(--page-accent);
  box-shadow: 0 4px 20px rgba(255,107,53,0.12);
}
.page-about__service-num {
  display: inline-block;
  font-family: var(--font-data);
  font-size: var(--size-h3);
  color: var(--page-accent);
  line-height: 1;
  margin-bottom: var(--space-sm, 0.5rem);
  opacity: 0.7;
  transition: opacity var(--transition-fast, 150ms ease);
}
.page-about__service-card:hover .page-about__service-num,
.page-about__service-card:focus-within .page-about__service-num {
  opacity: 1;
}
.page-about__service-title {
  font-family: var(--font-headings);
  font-size: var(--size-h3);
  color: var(--page-heading);
  margin: 0 0 var(--space-xs, 0.25rem) 0;
  line-height: 1.25;
}
.page-about__service-title::after {
  content: "";
  display: block;
  width: 32px;
  height: 2px;
  margin-top: var(--space-sm, 0.5rem);
  background: linear-gradient(90deg, var(--page-neon-from), var(--page-neon-to));
  border-radius: 1px;
  transition: width var(--transition-base, 300ms ease);
}
.page-about__service-card:hover .page-about__service-title::after,
.page-about__service-card:focus-within .page-about__service-title::after {
  width: 56px;
}
.page-about__service-brief {
  font-size: var(--size-body);
  color: var(--color-metallic-silver, #B0B0B0);
  margin: var(--space-sm, 0.5rem) 0 0 0;
  line-height: 1.5;
}
.page-about__service-detail {
  max-height: 0;
  opacity: 0;
  overflow: hidden;
  transition: max-height var(--transition-base, 300ms ease),
              opacity var(--transition-base, 300ms ease),
              margin var(--transition-base, 300ms ease);
  margin-top: 0;
}
.page-about__service-card:hover .page-about__service-detail,
.page-about__service-card:focus-within .page-about__service-detail {
  max-height: 200px;
  opacity: 1;
  margin-top: var(--space-md, 1rem);
}
.page-about__service-detail p {
  font-size: var(--size-small, 0.875rem);
  line-height: 1.6;
  color: var(--page-text);
  margin: 0;
  border-top: 1px solid var(--page-border);
  padding-top: var(--space-sm, 0.5rem);
}
.page-about__services-bg {
  width: 100%;
  overflow: hidden;
  border-radius: var(--radius-sm, 2px);
  margin-top: var(--space-sm, 0.5rem);
}
.page-about__bg-img {
  display: block;
  width: 100%;
  height: auto;
  max-width: 100%;
  object-fit: cover;
  opacity: 0.6;
}

/* ── 跨设备体验区 ── */
.page-about__devices-content {
  display: flex;
  flex-direction: column;
  gap: var(--space-xl, 2rem);
  align-items: flex-start;
}
.page-about__devices-image {
  flex: 0 0 auto;
  width: 100%;
  max-width: 800px;
}
.page-about__devices-img {
  display: block;
  width: 100%;
  height: auto;
  max-width: 100%;
  border-radius: var(--radius-md, 4px);
  box-shadow: var(--shadow-card, 0 2px 8px rgba(0,0,0,0.3));
  background: var(--page-card-bg);
  object-fit: cover;
}
.page-about__devices-text {
  flex: 1 1 0%;
  min-width: 0;
}
.page-about__devices-text p {
  font-size: var(--size-body);
  line-height: 1.7;
  margin: 0 0 var(--space-md, 1rem) 0;
  max-width: 600px;
}
.page-about__devices-link {
  margin-top: var(--space-sm, 0.5rem);
}

/* ── CTA 区域 ── */
.page-about__cta {
  text-align: center;
}
.page-about__cta p {
  font-size: var(--size-body);
  color: var(--color-metallic-silver, #B0B0B0);
  margin: 0 0 var(--space-lg, 1.5rem) 0;
}
.page-about__cta-links {
  display: flex;
  flex-direction: column;
  gap: var(--space-md, 1rem);
  align-items: center;
  justify-content: center;
}
.page-about__cta-links .btn {
  min-width: 200px;
}

/* ── 分隔线间距微调 ── */
.page-about .divider {
  margin: var(--space-lg, 1.5rem) 0 var(--page-section-gap) 0;
}

/* ── 桌面端布局 ── */
@media (min-width: 768px) {
  .page-about__brand {
    flex-direction: row;
    align-items: center;
    gap: var(--space-2xl, 3rem);
  }
  .page-about__brand-image {
    flex: 0 0 50%;
    max-width: 50%;
    margin: 0;
  }
  .page-about__brand-text {
    flex: 1 1 50%;
  }

  .page-about__services-grid {
    grid-template-columns: 1fr 1fr;
  }

  .page-about__devices-content {
    flex-direction: row;
    align-items: center;
  }
  .page-about__devices-image {
    flex: 0 0 55%;
    max-width: 55%;
  }
  .page-about__devices-text {
    flex: 1 1 45%;
  }

  .page-about__cta-links {
    flex-direction: row;
    gap: var(--space-lg, 1.5rem);
  }
}

@media (min-width: 1024px) {
  .page-about__brand-text h1 {
    font-size: var(--size-h1);
  }
  .page-about__services-grid {
    gap: var(--space-xl, 2rem);
  }
  .page-about__service-card {
    padding: var(--space-xl, 2rem);
  }
}