.page-about {
  --about-hero-bg: var(--color-dark);
  --about-section-gap: clamp(2rem, 6vw, 4rem);
  --about-card-radius: var(--radius-md);
  --about-accent-line: var(--color-primary);
}

/* 移动端优先基础样式 */
.page-about .page-container {
  padding-top: 0; /* 移除父级默认上内边距，由章节自行控制 */
}

/* 面包屑导航 */
.page-about .breadcrumb {
  display: flex;
  align-items: center;
  gap: 0.5rem;
  padding: 0.75rem 0 0;
  font-family: var(--font-mono);
  font-size: 0.875rem;
  color: var(--color-medium-gray);
}
.page-about .breadcrumb a {
  color: var(--color-medium-gray);
  text-decoration: none;
  transition: color var(--transition-fast);
}
.page-about .breadcrumb a:hover,
.page-about .breadcrumb a:focus-visible {
  color: var(--color-primary);
}
.page-about .breadcrumb__sep {
  color: var(--color-medium-gray);
  user-select: none;
}

/* Hero 章节 — 01 品牌 */
.page-about .section-hero {
  position: relative;
  display: flex;
  flex-direction: column;
  gap: 1.5rem;
  padding: 1.5rem 0 3rem;
  background: var(--about-hero-bg);
  margin: 0 calc(-1 * var(--max-width) / 2 + 50%);
  width: 100vw;
  padding-left: calc((100vw - min(100vw, var(--max-width))) / 2 + 1rem);
  padding-right: calc((100vw - min(100vw, var(--max-width))) / 2 + 1rem);
  overflow: hidden;
}
@media (min-width: 768px) {
  .page-about .section-hero {
    flex-direction: row;
    align-items: center;
    gap: 3rem;
    padding: 3rem calc((100vw - min(100vw, var(--max-width))) / 2 + 1.5rem);
  }
}
.page-about .hero__content {
  flex: 1 1 55%;
  z-index: 2;
  position: relative;
}
.page-about .hero__label {
  display: inline-block;
  font-family: var(--font-mono);
  font-size: 0.875rem;
  color: var(--color-primary);
  letter-spacing: 0.1em;
  text-transform: uppercase;
  margin-bottom: 0.5rem;
}
.page-about .hero__title {
  font-family: var(--font-heading);
  font-size: clamp(2.25rem, 8vw, 3.75rem);
  font-weight: 800;
  color: var(--color-white);
  line-height: 1.1;
  margin: 0 0 0.75rem;
  text-transform: uppercase;
}
.page-about .hero__subtitle {
  font-family: var(--font-mono);
  font-size: clamp(1rem, 3vw, 1.25rem);
  color: var(--color-medium-gray);
  line-height: 1.5;
  margin: 0;
  max-width: 34ch;
}
.page-about .hero__media {
  flex: 0 0 auto;
  z-index: 2;
  position: relative;
  max-width: 400px;
  width: 100%;
}
.page-about .hero__img {
  display: block;
  width: 100%;
  max-width: 100%;
  height: auto;
  aspect-ratio: 4 / 3;
  object-fit: cover;
  border-radius: var(--about-card-radius);
  box-shadow: var(--shadow-card);
}
.page-about .hero__skew {
  position: absolute;
  top: 0;
  right: -10%;
  width: 35%;
  height: 100%;
  background: var(--color-primary-gradient);
  clip-path: polygon(20% 0, 100% 0, 100% 100%, 0% 100%);
  opacity: 0.12;
  z-index: 1;
  pointer-events: none;
}
@media (max-width: 767px) {
  .page-about .hero__skew {
    width: 50%;
    right: -20%;
    opacity: 0.08;
  }
}

/* 通用章节容器 */
.page-about .section-chapter {
  padding: var(--about-section-gap) 0;
  position: relative;
}
.page-about .section-title {
  display: flex;
  align-items: baseline;
  gap: 0.75rem;
  margin-bottom: 1.75rem;
  border-bottom: 1px solid var(--color-border);
  padding-bottom: 0.5rem;
}
.page-about .section__number {
  font-family: var(--font-heading);
  font-size: clamp(2.5rem, 8vw, 4.5rem);
  font-weight: 800;
  color: var(--color-primary);
  line-height: 1;
  opacity: 0.35;
  letter-spacing: -0.03em;
}
.page-about .section__heading {
  font-family: var(--font-heading);
  font-size: clamp(1.5rem, 5vw, 2.25rem);
  font-weight: 800;
  color: var(--color-white);
  margin: 0;
  line-height: 1.2;
  text-transform: uppercase;
}
.page-about .section__skew {
  height: 3px;
  background: var(--color-primary-gradient);
  width: 80%;
  max-width: 300px;
  clip-path: polygon(0 0, 100% 0, 98% 100%, 0% 100%);
  margin-top: var(--about-section-gap);
  opacity: 0.6;
}

/* Bento 网格 */
.page-about .grid-bento {
  display: grid;
  grid-template-columns: 1fr;
  gap: 1rem;
}
@media (min-width: 640px) {
  .page-about .grid-bento {
    grid-template-columns: repeat(2, 1fr);
    gap: 1.25rem;
  }
  .page-about .grid-bento--alt {
    grid-template-areas:
      "a b"
      "a c";
  }
  .page-about .grid-bento--alt .data-card:nth-child(1) { grid-area: a; }
  .page-about .grid-bento--alt .data-card:nth-child(2) { grid-area: b; }
  .page-about .grid-bento--alt .data-card:nth-child(3) { grid-area: c; }
  .page-about .grid-bento--services {
    grid-template-columns: repeat(2, 1fr);
  }
  .page-about .grid-bento--compact {
    grid-template-columns: repeat(3, 1fr);
  }
}
@media (min-width: 1024px) {
  .page-about .grid-bento--services {
    grid-template-columns: repeat(4, 1fr);
  }
}

/* 数据卡片 */
.page-about .data-card {
  position: relative;
  background: var(--color-dark-card);
  border: 1px solid var(--color-border);
  border-radius: var(--about-card-radius);
  padding: 1.5rem 1rem 1rem 1rem;
  transition: transform var(--transition-smooth), box-shadow var(--transition-smooth);
  overflow: hidden;
  cursor: default;
}
.page-about .data-card:hover {
  transform: translateY(-4px);
  box-shadow: var(--shadow-hover);
}
.page-about .data-card--large {
  grid-row: span 2;
}
.page-about .data-card--dark {
  background: var(--color-dark);
  border-color: rgba(255,255,255,0.05);
}
.page-about .data-card--accent {
  border-left: 4px solid var(--color-primary);
}
.page-about .data-card__content {
  position: relative;
  z-index: 2;
}
.page-about .data-card__title {
  font-family: var(--font-heading);
  font-size: clamp(1.125rem, 3vw, 1.375rem);
  font-weight: 800;
  color: var(--color-white);
  margin: 0 0 0.5rem;
  line-height: 1.3;
}
.page-about .data-card__desc {
  font-family: var(--font-mono);
  font-size: 0.9375rem;
  color: var(--color-light-gray);
  line-height: 1.6;
  margin: 0;
}
.page-about .data-card__index {
  position: absolute;
  bottom: 0.5rem;
  right: 0.75rem;
  font-family: var(--font-mono);
  font-size: 0.75rem;
  color: var(--color-medium-gray);
  letter-spacing: 0.05em;
  opacity: 0.6;
}
.page-about .data-card__tag {
  display: inline-block;
  margin-top: 0.75rem;
  font-family: var(--font-mono);
  font-size: 0.75rem;
  color: var(--color-accent);
  background: rgba(0,255,136,0.1);
  padding: 0.2rem 0.5rem;
  border-radius: 2px;
  border: 1px solid rgba(0,255,136,0.2);
}
/* 卡片悬停翻转交互（渐进增强，内容始终可见） */
@media (hover: hover) {
  .page-about .data-card:hover .data-card__index {
    opacity: 1;
    color: var(--color-primary);
    transition: opacity var(--transition-fast), color var(--transition-fast);
  }
  .page-about .data-card:hover .data-card__tag {
    background: rgba(0,255,136,0.2);
    transition: background var(--transition-fast);
  }
}

/* 服务章节 */
.page-about .services__intro {
  margin-bottom: 1.5rem;
}
.page-about .services__img {
  display: block;
  width: 100%;
  max-width: 600px;
  height: auto;
  aspect-ratio: 12 / 5;
  object-fit: cover;
  border-radius: var(--about-card-radius);
  box-shadow: var(--shadow-card);
}
.page-about .services__cta {
  display: flex;
  flex-wrap: wrap;
  gap: 1rem;
  margin-top: 1.75rem;
}
.page-about .btn {
  display: inline-flex;
  align-items: center;
  padding: 0.75rem 1.75rem;
  font-family: var(--font-heading);
  font-weight: 700;
  font-size: 0.9375rem;
  text-transform: uppercase;
  letter-spacing: 0.05em;
  border-radius: var(--radius-sm);
  text-decoration: none;
  transition: background var(--transition-fast), color var(--transition-fast), border var(--transition-fast), transform var(--transition-fast);
  cursor: pointer;
  border: 1px solid transparent;
}
.page-about .btn--primary {
  background: var(--color-primary);
  color: var(--color-white);
  border-color: var(--color-primary);
}
.page-about .btn--primary:hover,
.page-about .btn--primary:focus-visible {
  background: var(--color-primary-light);
  border-color: var(--color-primary-light);
  transform: translateY(-2px);
}
.page-about .btn--ghost {
  background: transparent;
  color: var(--color-white);
  border-color: var(--color-border);
}
.page-about .btn--ghost:hover,
.page-about .btn--ghost:focus-visible {
  background: rgba(255,255,255,0.05);
  border-color: var(--color-primary);
}

/* 用户价值章节 */
.page-about .value__layout {
  display: flex;
  flex-direction: column;
  gap: 2rem;
  align-items: flex-start;
}
@media (min-width: 768px) {
  .page-about .value__layout {
    flex-direction: row;
    align-items: center;
    gap: 3rem;
  }
}
.page-about .value__text {
  flex: 1 1 55%;
}
.page-about .value__lead {
  font-family: var(--font-heading);
  font-size: clamp(1.125rem, 3vw, 1.5rem);
  font-weight: 700;
  color: var(--color-white);
  line-height: 1.5;
  margin: 0 0 1rem;
}
.page-about .value__text p {
  font-family: var(--font-mono);
  font-size: 1rem;
  color: var(--color-light-gray);
  line-height: 1.7;
  margin: 0 0 1rem;
}
.page-about .tag-group {
  display: flex;
  flex-wrap: wrap;
  gap: 0.5rem;
  margin: 1.5rem 0;
}
.page-about .tag-item {
  display: inline-block;
  padding: 0.35rem 0.75rem;
  font-family: var(--font-mono);
  font-size: 0.8125rem;
  color: var(--color-accent);
  border: 1px solid rgba(0,255,136,0.3);
  border-radius: 2px;
  cursor: pointer;
  transition: background var(--transition-fast), color var(--transition-fast);
}
.page-about .tag-item:hover,
.page-about .tag-item:focus-visible {
  background: rgba(0,255,136,0.15);
  color: var(--color-white);
}
.page-about .value__media {
  flex: 0 0 auto;
  max-width: 320px;
  width: 100%;
  position: relative;
}
.page-about .value__img {
  display: block;
  width: 100%;
  max-width: 100%;
  height: auto;
  aspect-ratio: 1 / 1;
  object-fit: cover;
  border-radius: 50%;
  box-shadow: var(--shadow-card);
  border: 2px solid var(--color-primary);
}
.page-about .value__highlight {
  display: flex;
  gap: 0.75rem;
  margin-top: 1rem;
  justify-content: center;
}
.page-about .data-highlight {
  font-family: var(--font-mono);
  font-size: 0.875rem;
  color: var(--color-accent);
  background: rgba(0,255,136,0.08);
  padding: 0.25rem 0.5rem;
  border-radius: 2px;
  border: 1px solid rgba(0,255,136,0.15);
}

/* 原则与边界章节 */
.page-about .grid-bento--compact .data-card {
  padding: 1.25rem;
}
.page-about .grid-bento--compact .data-card__title {
  font-size: 1.125rem;
  margin-bottom: 0.375rem;
}
.page-about .grid-bento--compact .data-card__desc {
  font-size: 0.875rem;
  color: var(--color-medium-gray);
}

/* 媒体查询：窄屏优化 */
@media (max-width: 639px) {
  .page-about .section-hero {
    padding-top: 1rem;
    padding-bottom: 2rem;
    gap: 1rem;
  }
  .page-about .hero__media {
    max-width: 280px;
    margin: 0 auto;
  }
  .page-about .data-card--large {
    grid-row: auto;
  }
  .page-about .services__cta {
    flex-direction: column;
    align-items: stretch;
  }
  .page-about .btn {
    justify-content: center;
  }
  .page-about .value__layout {
    gap: 1.5rem;
  }
  .page-about .value__media {
    max-width: 240px;
    margin: 0 auto;
  }
  .page-about .value__highlight {
    flex-wrap: wrap;
  }
  .page-about .grid-bento--compact {
    grid-template-columns: 1fr;
  }
}

/* 桌面大屏微调 */
@media (min-width: 1200px) {
  .page-about .section-chapter {
    padding: 3.5rem 0;
  }
  .page-about .hero__title {
    font-size: 4rem;
  }
  .page-about .grid-bento {
    gap: 1.5rem;
  }
}
</<PAGE_CSS>>