.page-about {
  --color-primary: #8B0000;
  --color-secondary: #FFD700;
  --color-bg: #F5E6D0;
  --color-bg-dark: #E8D5B8;
  --color-dark: #1A1A1A;
  --color-mid: #333333;
  --color-light: #B8A88A;
  --color-glass: rgba(255, 255, 255, 0.15);
  --color-glass-border: rgba(0, 0, 0, 0.08);
  --font-heading: Impact, 'Arial Black', sans-serif;
  --font-body: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, 'Helvetica Neue', Arial, sans-serif;
  --font-number: 'Courier New', Consolas, 'Liberation Mono', monospace;
  --space-sm: 0.5rem;
  --space-md: 1rem;
  --space-lg: 2rem;
  --space-xl: 4rem;
  --space-2xl: 6rem;
  --max-width: 1200px;
  --shadow-card: 0 4px 20px rgba(0,0,0,0.08);
  --shadow-hover: 0 12px 40px rgba(0,0,0,0.15);
  --transition-fast: 0.2s ease;
  --transition-med: 0.35s ease;
  --transition-slow: 0.5s ease;
  --border-radius: 4px;

  display: block;
  background-color: var(--color-bg);
  padding-bottom: var(--space-2xl);
  position: relative;
  z-index: 1;
}

/* ── 面包屑 ── */
.page-about .breadcrumb {
  max-width: var(--max-width);
  margin: 0 auto;
  padding: var(--space-lg) var(--space-md) var(--space-xs);
  font-family: var(--font-body);
  font-size: 0.875rem;
  color: var(--color-mid);
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: var(--space-sm);
}
.page-about .breadcrumb a {
  color: var(--color-primary);
  text-decoration: none;
  border-bottom: 1px solid transparent;
  transition: border-color var(--transition-fast);
}
.page-about .breadcrumb a:hover {
  border-color: var(--color-primary);
}
.page-about .breadcrumb .separator {
  color: var(--color-light);
  user-select: none;
}
.page-about .breadcrumb [aria-current="page"] {
  color: var(--color-dark);
  font-weight: 600;
}

/* ── 公用容器 ── */
.page-about .container {
  max-width: var(--max-width);
  margin: 0 auto;
  padding-left: var(--space-md);
  padding-right: var(--space-md);
}

/* ── 框景首屏 ── */
.page-about .frame-section {
  padding-top: var(--space-lg);
  padding-bottom: var(--space-xl);
}
.page-about .frame-viewport {
  position: relative;
  border: 2px solid var(--color-dark);
  outline: 1px solid var(--color-light);
  outline-offset: 4px;
  padding: var(--space-lg);
  background-color: var(--color-bg);
  box-shadow: inset 0 0 0 1px var(--color-glass-border);
  min-height: 320px;
}
.page-about .frame-viewport::before,
.page-about .frame-viewport::after {
  content: "";
  position: absolute;
  width: 16px;
  height: 16px;
  border-color: var(--color-secondary);
  border-style: solid;
  pointer-events: none;
}
.page-about .frame-viewport::before {
  top: -2px;
  left: -2px;
  border-width: 3px 0 0 3px;
}
.page-about .frame-viewport::after {
  bottom: -2px;
  right: -2px;
  border-width: 0 3px 3px 0;
}
.page-about .frame-content {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: var(--space-xl);
}
.page-about .brand-intro {
  flex: 1 1 auto;
  text-align: center;
}
.page-about .brand-icon-wrap {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  margin-bottom: var(--space-md);
}
.page-about .brand-icon-svg {
  display: block;
  width: 100px;
  height: 100px;
  filter: drop-shadow(0 2px 8px rgba(255, 215, 0, 0.25));
}
.page-about .brand-name {
  font-family: var(--font-heading);
  font-size: 3.2rem;
  line-height: 1.1;
  letter-spacing: 0.05em;
  color: var(--color-primary);
  margin: 0 0 var(--space-sm);
  text-transform: uppercase;
  word-break: break-word;
}
.page-about .brand-tagline {
  font-family: var(--font-body);
  font-size: 1.1rem;
  line-height: 1.7;
  color: var(--color-mid);
  max-width: 480px;
  margin: 0 auto;
}
.page-about .brand-visual {
  flex: 0 0 auto;
  width: 100%;
  max-width: 400px;
}
.page-about .brand-hero-img {
  display: block;
  width: 100%;
  height: auto;
  max-width: 100%;
  object-fit: contain;
  border-radius: var(--border-radius);
  background-color: var(--color-bg-dark);
}

/* ── 通用章节编号 ── */
.page-about .section-number-wrap {
  display: flex;
  align-items: baseline;
  gap: var(--space-md);
  margin-bottom: var(--space-lg);
}
.page-about .section-number {
  font-family: var(--font-number);
  font-size: 3.5rem;
  font-weight: 700;
  line-height: 1;
  color: var(--color-primary);
  letter-spacing: 0.03em;
}
.page-about .section-number-label {
  font-family: var(--font-heading);
  font-size: 1.6rem;
  text-transform: uppercase;
  letter-spacing: 0.08em;
  color: var(--color-mid);
  border-left: 3px solid var(--color-secondary);
  padding-left: var(--space-md);
  line-height: 1.3;
}

/* ── 01 运营信息 ── */
.page-about .section-info {
  padding: var(--space-xl) 0;
  position: relative;
  overflow: hidden;
}
.page-about .info-layout {
  position: relative;
}
.page-about .info-content {
  position: relative;
  display: grid;
  grid-template-columns: 1fr;
  gap: var(--space-lg);
  background-image:
    linear-gradient(90deg, var(--color-glass-border) 1px, transparent 1px),
    linear-gradient(0deg, var(--color-glass-border) 1px, transparent 1px);
  background-size: 40px 40px;
  background-position: 0 0;
  padding: var(--space-lg);
  border-radius: var(--border-radius);
}
.page-about .info-bg-map {
  position: absolute;
  inset: 0;
  opacity: 0.10;
  pointer-events: none;
  overflow: hidden;
  border-radius: var(--border-radius);
}
.page-about .map-bg-img {
  display: block;
  width: 100%;
  height: 100%;
  object-fit: cover;
  object-position: center;
}
.page-about .info-list {
  list-style: none;
  margin: 0;
  padding: 0;
  display: flex;
  flex-direction: column;
  gap: var(--space-lg);
  position: relative;
  z-index: 1;
}
.page-about .info-item {
  display: flex;
  flex-direction: column;
  gap: var(--space-xs);
  border-bottom: 1px solid var(--color-glass-border);
  padding-bottom: var(--space-md);
}
.page-about .info-item:last-child {
  border-bottom: none;
  padding-bottom: 0;
}
.page-about .info-key {
  font-family: var(--font-heading);
  font-size: 0.9rem;
  text-transform: uppercase;
  letter-spacing: 0.12em;
  color: var(--color-secondary);
  background-color: var(--color-primary);
  display: inline-block;
  padding: 0.15rem 0.8rem;
  border-radius: 2px;
  align-self: flex-start;
}
.page-about .info-value {
  font-family: var(--font-body);
  font-size: 1rem;
  line-height: 1.7;
  color: var(--color-dark);
}
.page-about .info-value a {
  color: var(--color-primary);
  text-decoration: underline;
  text-underline-offset: 2px;
  transition: color var(--transition-fast);
}
.page-about .info-value a:hover {
  color: var(--color-mid);
}

/* ── 02 服务范围 ── */
.page-about .section-services {
  padding: var(--space-xl) 0;
}
.page-about .services-layout {
  position: relative;
}
.page-about .services-grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: var(--space-md);
}
.page-about .service-item {
  border: 1px solid var(--color-glass-border);
  border-left: 4px solid var(--color-primary);
  background-color: rgba(255, 255, 255, 0.45);
  backdrop-filter: blur(2px);
  border-radius: var(--border-radius);
  transition: box-shadow var(--transition-med), transform var(--transition-fast);
  overflow: hidden;
}
.page-about .service-item:hover {
  box-shadow: var(--shadow-card);
  transform: translateY(-2px);
}
.page-about .service-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: var(--space-md) var(--space-lg);
  cursor: pointer;
  user-select: none;
  transition: background-color var(--transition-fast);
}
.page-about .service-header:hover {
  background-color: rgba(139, 0, 0, 0.04);
}
.page-about .service-name {
  font-family: var(--font-heading);
  font-size: 1.2rem;
  letter-spacing: 0.04em;
  color: var(--color-dark);
  text-transform: uppercase;
}
.page-about .expand-icon {
  font-family: var(--font-number);
  font-size: 1.6rem;
  line-height: 1;
  color: var(--color-primary);
  transition: transform var(--transition-med);
}
.page-about .service-item[data-open] .expand-icon {
  transform: rotate(45deg);
}
.page-about .service-body {
  max-height: 0;
  overflow: hidden;
  transition: max-height var(--transition-med), padding var(--transition-med);
  padding: 0 var(--space-lg);
  border-top: 0 solid var(--color-glass-border);
}
.page-about .service-item[data-open] .service-body {
  max-height: 300px;
  padding: var(--space-md) var(--space-lg) var(--space-lg);
  border-top-width: 1px;
}
.page-about .service-body p {
  font-family: var(--font-body);
  font-size: 0.95rem;
  line-height: 1.8;
  color: var(--color-mid);
  margin: 0;
}
.page-about .service-link {
  display: inline-block;
  margin-top: var(--space-sm);
  color: var(--color-primary);
  font-weight: 600;
  text-decoration: underline;
  text-underline-offset: 2px;
  transition: color var(--transition-fast);
}
.page-about .service-link:hover {
  color: var(--color-secondary);
}

/* ── 03 品牌承诺 ── */
.page-about .section-commit {
  padding: var(--space-xl) 0;
}
.page-about .commit-layout {
  position: relative;
}
.page-about .commit-grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: var(--space-xl);
  align-items: center;
}
.page-about .commit-visual {
  order: 1;
  width: 100%;
  max-width: 400px;
  margin: 0 auto;
}
.page-about .commit-img {
  display: block;
  width: 100%;
  height: auto;
  object-fit: contain;
  border-radius: var(--border-radius);
  box-shadow: var(--shadow-card);
  background-color: var(--color-bg-dark);
}
.page-about .commit-text {
  order: 2;
}
.page-about .commit-list {
  list-style: none;
  margin: 0 0 var(--space-lg);
  padding: 0;
  display: flex;
  flex-direction: column;
  gap: var(--space-md);
}
.page-about .commit-item {
  display: flex;
  align-items: flex-start;
  gap: var(--space-md);
  font-family: var(--font-body);
  font-size: 1rem;
  line-height: 1.7;
  color: var(--color-dark);
  padding: var(--space-sm) 0;
  border-bottom: 1px solid var(--color-glass-border);
}
.page-about .commit-item:last-child {
  border-bottom: none;
}
.page-about .commit-mark {
  color: var(--color-secondary);
  font-size: 1.1rem;
  flex-shrink: 0;
  margin-top: 0.2em;
}
.page-about .commit-links {
  display: flex;
  flex-wrap: wrap;
  gap: var(--space-md);
}
.page-about .btn-secondary {
  display: inline-block;
  padding: 0.6rem 1.8rem;
  font-family: var(--font-body);
  font-size: 0.95rem;
  font-weight: 600;
  color: var(--color-primary);
  background-color: transparent;
  border: 2px solid var(--color-primary);
  border-radius: var(--border-radius);
  text-decoration: none;
  transition: background-color var(--transition-fast), color var(--transition-fast), border-color var(--transition-fast);
}
.page-about .btn-secondary:hover {
  background-color: var(--color-primary);
  color: #fff;
  border-color: var(--color-primary);
}

/* ── 相关链接 ── */
.page-about .section-related {
  padding: var(--space-2xl) 0 var(--space-xl);
}
.page-about .related-heading {
  font-family: var(--font-heading);
  font-size: 1.4rem;
  text-transform: uppercase;
  letter-spacing: 0.08em;
  color: var(--color-mid);
  margin: 0 0 var(--space-lg);
  text-align: center;
  position: relative;
}
.page-about .related-heading::after {
  content: "";
  display: block;
  width: 60px;
  height: 2px;
  background: var(--color-secondary);
  margin: var(--space-sm) auto 0;
}
.page-about .related-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: var(--space-md);
}
.page-about .related-card {
  display: flex;
  flex-direction: column;
  padding: var(--space-md);
  background-color: rgba(255, 255, 255, 0.5);
  border: 1px solid var(--color-glass-border);
  border-radius: var(--border-radius);
  text-decoration: none;
  transition: box-shadow var(--transition-fast), transform var(--transition-fast);
}
.page-about .related-card:hover {
  box-shadow: var(--shadow-hover);
  transform: translateY(-3px);
}
.page-about .related-card-icon {
  font-family: var(--font-number);
  font-size: 1.5rem;
  color: var(--color-primary);
  margin-bottom: var(--space-sm);
  transition: transform var(--transition-fast);
}
.page-about .related-card:hover .related-card-icon {
  transform: translateX(4px);
}
.page-about .related-card-title {
  font-family: var(--font-heading);
  font-size: 1.1rem;
  letter-spacing: 0.04em;
  color: var(--color-dark);
  text-transform: uppercase;
  margin-bottom: var(--space-xs);
}
.page-about .related-card-desc {
  font-family: var(--font-body);
  font-size: 0.85rem;
  line-height: 1.5;
  color: var(--color-mid);
}

/* ── 桌面端（≥768px） ── */
@media (min-width: 768px) {
  .page-about {
    padding-bottom: var(--space-2xl);
  }
  .page-about .frame-viewport {
    padding: var(--space-xl);
    min-height: 420px;
  }
  .page-about .frame-content {
    flex-direction: row;
    align-items: center;
    gap: var(--space-2xl);
  }
  .page-about .brand-intro {
    text-align: left;
    flex: 1 1 60%;
  }
  .page-about .brand-tagline {
    margin: 0;
  }
  .page-about .brand-visual {
    flex: 0 0 280px;
    max-width: 280px;
  }
  .page-about .brand-icon-svg {
    width: 120px;
    height: 120px;
  }
  .page-about .brand-name {
    font-size: 4.2rem;
  }
  .page-about .brand-tagline {
    font-size: 1.2rem;
  }

  /* 章节编号 */
  .page-about .section-number {
    font-size: 5rem;
  }
  .page-about .section-number-label {
    font-size: 1.8rem;
  }

  /* 01 布局 */
  .page-about .info-content {
    grid-template-columns: 1fr;
    padding: var(--space-xl);
  }
  .page-about .info-list {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: var(--space-md) var(--space-xl);
  }
  .page-about .info-item {
    padding-bottom: var(--space-sm);
  }

  /* 02 网格 */
  .page-about .services-grid {
    grid-template-columns: 1fr 1fr;
  }

  /* 03 布局 */
  .page-about .commit-grid {
    grid-template-columns: 1fr 1.5fr;
    gap: var(--space-2xl);
  }
  .page-about .commit-visual {
    order: 0;
    max-width: 100%;
  }

  /* 相关链接 */
  .page-about .related-grid {
    grid-template-columns: repeat(4, 1fr);
  }
}

/* ── 宽屏（≥1024px） ── */
@media (min-width: 1024px) {
  .page-about .brand-name {
    font-size: 5rem;
  }
  .page-about .brand-visual {
    flex: 0 0 360px;
    max-width: 360px;
  }
  .page-about .frame-viewport {
    padding: var(--space-2xl);
  }
  .page-about .section-number {
    font-size: 6rem;
  }
  .page-about .services-grid {
    grid-template-columns: repeat(3, 1fr);
  }
  .page-about .info-list {
    grid-template-columns: repeat(2, 1fr);
  }
}

/* ── 小屏微调 ── */
@media (max-width: 420px) {
  .page-about .brand-name {
    font-size: 2.2rem;
  }
  .page-about .section-number {
    font-size: 2.8rem;
  }
  .page-about .related-grid {
    grid-template-columns: 1fr;
  }
  .page-about .frame-viewport {
    padding: var(--space-md);
  }
}