.page-about {
  --frame-border-color: var(--green, #1B7A3D);
  --frame-bg: var(--bg-light, #F8F9FA);
  --feature-shadow: var(--shadow, 0 2px 8px rgba(0,0,0,0.08));
  --data-bg-color: var(--bg-dark, #1A1A2E);
  --data-text-color: var(--text-light, #FFFFFF);
  --stat-color: var(--orange, #F28C28);
}

.page-about .breadcrumb {
  max-width: var(--max-width, 1200px);
  margin: 0 auto;
  padding: 1rem 1.5rem 0;
  font-family: var(--font-body, 'Segoe UI', 'Helvetica Neue', Arial, sans-serif);
  font-size: 0.875rem;
}
.page-about .breadcrumb ol {
  list-style: none;
  padding: 0;
  margin: 0;
  display: flex;
  flex-wrap: wrap;
  gap: 0.5rem;
}
.page-about .breadcrumb li::after {
  content: " / ";
  margin-left: 0.5rem;
  color: #888;
}
.page-about .breadcrumb li:last-child::after {
  content: none;
}
.page-about .breadcrumb a {
  color: var(--green, #1B7A3D);
  text-decoration: underline;
  text-underline-offset: 2px;
}
.page-about .breadcrumb a:hover {
  color: var(--green-light, #2E9E50);
}

.page-about-hero {
  max-width: var(--max-width, 1200px);
  margin: 0 auto;
  padding: 1.5rem 1.5rem 2rem;
}
.hero-frame {
  display: flex;
  flex-wrap: wrap;
  gap: 2rem;
  align-items: center;
  border: 4px solid var(--frame-border-color);
  background: var(--frame-bg);
  padding: 2rem;
  box-shadow: inset 0 0 0 2px rgba(27,122,61,0.1);
  position: relative;
  min-height: 200px;
}
.hero-frame::before {
  content: "";
  position: absolute;
  top: -8px;
  left: -8px;
  right: -8px;
  bottom: -8px;
  border: 2px dashed var(--orange, #F28C28);
  pointer-events: none;
}
.hero-text {
  flex: 1 1 280px;
}
.hero-text .page-title {
  font-family: var(--font-heading, Georgia, 'Times New Roman', serif);
  font-weight: 700;
  font-size: 3rem;
  line-height: 1.1;
  margin: 0 0 0.5rem;
  color: var(--text-dark, #1C1C1E);
}
.hero-declaration {
  font-family: var(--font-body, 'Segoe UI', 'Helvetica Neue', Arial, sans-serif);
  font-size: 1.25rem;
  line-height: 1.6;
  color: #444;
  max-width: 480px;
}
.hero-image {
  flex: 0 0 300px;
}
.hero-img {
  display: block;
  width: 100%;
  height: auto;
  max-width: 600px;
  object-fit: cover;
}

.page-about-vision,
.page-about-data .data-content,
.page-about-features,
.page-about-connect {
  max-width: var(--max-width, 1200px);
  margin: 0 auto;
  padding: 2rem 1.5rem;
}
.page-about h2 {
  font-family: var(--font-heading, Georgia, 'Times New Roman', serif);
  font-weight: 700;
  font-size: 2rem;
  line-height: 1.2;
  margin: 0 0 1.25rem;
  color: var(--text-dark, #1C1C1E);
  border-left: 6px solid var(--green, #1B7A3D);
  padding-left: 1rem;
}
.page-about .content-container {
  max-width: 720px;
}
.page-about-vision p {
  font-family: var(--font-body, 'Segoe UI', 'Helvetica Neue', Arial, sans-serif);
  font-size: 1.125rem;
  line-height: 1.8;
  color: #333;
  margin-bottom: 1rem;
}

/* 核心功能 */
.features-grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: 1.5rem;
  margin-top: 1rem;
}
.feature-card {
  background: #fff;
  box-shadow: var(--feature-shadow);
  padding: 1.5rem;
  border-radius: var(--border-radius, 4px);
  transition: transform var(--transition, 0.3s ease);
  display: flex;
  flex-direction: column;
  align-items: center;
  text-align: center;
}
.feature-card:hover {
  transform: translateY(-4px);
}
.feature-icon {
  width: 100px;
  height: 100px;
  margin-bottom: 1rem;
  overflow: hidden;
  border-radius: 50%;
  background: var(--bg-light, #F8F9FA);
  display: flex;
  align-items: center;
  justify-content: center;
}
.feature-img {
  width: 100%;
  height: 100%;
  object-fit: cover;
}
.feature-card h3 {
  font-family: var(--font-heading, Georgia, 'Times New Roman', serif);
  font-weight: 700;
  font-size: 1.25rem;
  margin: 0 0 0.5rem;
  color: var(--text-dark, #1C1C1E);
}
.feature-card p {
  font-family: var(--font-body, 'Segoe UI', 'Helvetica Neue', Arial, sans-serif);
  font-size: 0.95rem;
  line-height: 1.6;
  color: #555;
  margin: 0;
}
.features-cta {
  text-align: center;
  margin-top: 2rem;
  font-family: var(--font-body, 'Segoe UI', 'Helvetica Neue', Arial, sans-serif);
}
.features-cta a {
  color: var(--green, #1B7A3D);
  text-decoration: underline;
  font-weight: 600;
}

/* 数据承诺 */
.page-about-data {
  padding: 0 1.5rem;
  max-width: var(--max-width, 1200px);
  margin: 0 auto;
  display: flex;
  flex-wrap: wrap;
  gap: 2rem;
  align-items: center;
}
.data-backdrop {
  flex: 1 1 300px;
  max-width: 100%;
  background: var(--data-bg-color);
  border-radius: var(--border-radius, 4px);
  overflow: hidden;
}
.data-bg-img {
  display: block;
  width: 100%;
  height: auto;
  object-fit: cover;
}
.data-content {
  flex: 1 1 300px;
}
.data-list {
  list-style: none;
  padding: 0;
  margin: 1.5rem 0;
}
.data-list li {
  font-family: var(--font-body, 'Segoe UI', 'Helvetica Neue', Arial, sans-serif);
  font-size: 1rem;
  line-height: 1.8;
  margin-bottom: 0.75rem;
  padding: 0.5rem 0.75rem;
  background: rgba(27,122,61,0.05);
  border-left: 4px solid var(--green, #1B7A3D);
}
.page-about-data .stat {
  font-family: var(--font-mono, 'Fira Code', 'Courier New', monospace);
  font-weight: 700;
  color: var(--stat-color);
  font-size: 1.1rem;
}

.page-about-connect p {
  font-family: var(--font-body, 'Segoe UI', 'Helvetica Neue', Arial, sans-serif);
  font-size: 1.0625rem;
  line-height: 1.7;
  color: #333;
}
.page-about-connect a {
  color: var(--green, #1B7A3D);
  text-decoration: underline;
}

/* 滚动章节高亮 */
[data-section][data-visible] {
  transition: background var(--transition, 0.3s ease), box-shadow var(--transition, 0.3s ease);
}
[data-section][data-visible] {
  background-color: rgba(30,144,255,0.03);
  box-shadow: 0 0 0 2px rgba(30,144,255,0.15);
  border-radius: var(--border-radius, 4px);
}

/* 移动端优先 */
@media (min-width: 640px) {
  .features-grid {
    grid-template-columns: repeat(2, 1fr);
  }
}
@media (min-width: 900px) {
  .features-grid {
    grid-template-columns: repeat(3, 1fr);
  }
}
@media (max-width: 639px) {
  .page-about-hero {
    padding: 1rem;
  }
  .hero-frame {
    padding: 1.5rem 1rem;
    flex-direction: column;
    text-align: center;
  }
  .hero-text .page-title {
    font-size: 2.25rem;
  }
  .hero-declaration {
    font-size: 1rem;
    max-width: 100%;
  }
  .hero-image {
    flex-basis: auto;
    width: 100%;
    max-width: 300px;
  }
  .page-about h2 {
    font-size: 1.5rem;
  }
  .page-about-vision p {
    font-size: 1rem;
  }
  .page-about-data {
    flex-direction: column;
    padding: 1rem;
  }
  .data-backdrop {
    width: 100%;
  }
  .data-content {
    width: 100%;
  }
  .feature-card {
    padding: 1rem;
  }
  .feature-icon {
    width: 80px;
    height: 80px;
  }
}