/* ===== 页面专属样式：品牌故事 (page-about) ===== */
.page-about {
  --clr-about-line: var(--clr-border-olive);
  --clr-about-accent: var(--clr-primary-dark-gold);
  --clr-about-strong: var(--clr-accent-neon-orange);
  --about-timeline-width: 4px;
  --about-marker-size: 16px;
  --about-scale-gap: 40px;
}

/* 框景首屏 */
.page-about .about-hero {
  position: relative;
  overflow: hidden;
  border-bottom: var(--border-thick) solid var(--clr-border-olive);
  margin-bottom: 0;
}
.about-hero-frame {
  display: flex;
  flex-direction: column;
  align-items: stretch;
  position: relative;
}
.about-hero-image-wrap {
  position: absolute;
  inset: 0;
  z-index: 0;
}
.about-hero-bg {
  width: 100%;
  height: 100%;
  object-fit: cover;
  display: block;
  opacity: 0.25;
}
.about-hero-content {
  position: relative;
  z-index: 1;
  padding: var(--space-2xl) var(--space-lg);
  max-width: var(--max-width);
  margin: 0 auto;
  width: 100%;
  box-sizing: border-box;
}
.about-hero-scale {
  width: var(--about-timeline-width);
  height: 120px;
  background: var(--clr-about-accent);
  margin-bottom: var(--space-md);
  position: relative;
}
.about-hero-scale::before {
  content: '';
  position: absolute;
  top: 0;
  left: 50%;
  width: var(--about-marker-size);
  height: var(--about-marker-size);
  border: 2px solid var(--clr-about-accent);
  background: var(--clr-surface-dark-green);
  transform: translate(-50%, -50%) rotate(45deg);
}
.about-hero-title {
  font-family: var(--font-heading);
  font-weight: 800;
  font-size: clamp(2rem, 5vw, 3.5rem);
  letter-spacing: -0.02em;
  color: var(--clr-text-off-white);
  margin: var(--space-sm) 0;
}
.about-hero-sub {
  font-family: var(--font-heading);
  font-size: 1.25rem;
  font-weight: 600;
  color: var(--clr-text-muted-gold);
  margin-bottom: var(--space-md);
}
.about-hero-desc {
  font-family: var(--font-body);
  line-height: 1.6;
  max-width: 600px;
  color: var(--clr-text-off-white);
}

/* 核心能力区域 */
.about-core {
  background: var(--clr-bg-dark-rock);
  padding: var(--space-2xl) var(--space-lg);
  border-bottom: var(--border-medium) solid var(--clr-border-olive);
}
.about-core-container {
  max-width: var(--max-width);
  margin: 0 auto;
  width: 100%;
  box-sizing: border-box;
}
.about-section-title {
  font-family: var(--font-heading);
  font-weight: 800;
  font-size: 1.75rem;
  color: var(--clr-primary-dark-gold);
  margin-bottom: var(--space-xl);
  padding-bottom: var(--space-sm);
  border-bottom: var(--border-medium) solid var(--clr-border-olive);
  display: inline-block;
}

/* 时间线 */
.about-timeline {
  position: relative;
}
.about-timeline-list {
  list-style: none;
  margin: 0;
  padding: 0;
  position: relative;
}
.about-timeline-list::before {
  content: '';
  position: absolute;
  left: 12px;
  top: 0;
  bottom: 0;
  width: var(--about-timeline-width);
  background: var(--clr-about-line);
  z-index: 0;
}
.about-timeline-item {
  position: relative;
  margin-bottom: var(--space-lg);
  padding-left: calc(24px + var(--space-md));
}
.about-timeline-details {
  cursor: pointer;
}
.about-timeline-summary {
  display: flex;
  align-items: center;
  gap: var(--space-sm);
  position: relative;
  list-style: none;
  padding: var(--space-sm) 0;
  transition: color var(--transition-fast);
  color: var(--clr-text-off-white);
  font-family: var(--font-heading);
  font-weight: 600;
  font-size: 1.1rem;
}
.about-timeline-summary::-webkit-details-marker {
  display: none;
}
.about-timeline-summary:hover {
  color: var(--clr-accent-neon-orange);
}
.about-timeline-marker {
  width: var(--about-marker-size);
  height: var(--about-marker-size);
  border: 2px solid var(--clr-about-accent);
  background: var(--clr-surface-dark-green);
  display: inline-flex;
  align-items: center;
  justify-content: center;
  flex-shrink: 0;
  position: relative;
  z-index: 1;
}
.about-timeline-summary .about-timeline-marker::after {
  content: '';
  display: block;
  width: 8px;
  height: 8px;
  background: var(--clr-accent-neon-orange);
  border-radius: 50%;
  opacity: 0;
  transition: opacity var(--transition-fast);
}
.about-timeline-details[open] .about-timeline-marker::after {
  opacity: 1;
}
.about-timeline-label {
  flex: 1;
}
.about-timeline-body {
  margin-top: var(--space-sm);
  padding: var(--space-md);
  background: var(--clr-surface-dark-green);
  border: var(--border-medium) solid var(--clr-border-olive);
  box-shadow: var(--shadow-medium);
  transition: box-shadow var(--transition-med);
}
.about-timeline-body:hover {
  box-shadow: var(--shadow-heavy);
}
.about-timeline-body p {
  color: var(--clr-text-off-white);
  line-height: 1.6;
  margin-bottom: var(--space-md);
}
.about-timeline-body img {
  max-width: 100%;
  height: auto;
  display: block;
  border: 1px solid var(--clr-border-olive);
}

/* 技术特色 */
.about-tech {
  padding: var(--space-2xl) var(--space-lg);
  background: var(--clr-primary-deep-green);
}
.about-tech-container {
  max-width: var(--max-width);
  margin: 0 auto;
  width: 100%;
  box-sizing: border-box;
}
.about-tech-grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: var(--space-lg);
}
.about-tech-card {
  background: var(--clr-surface-dark-green);
  border: var(--border-medium) solid var(--clr-border-olive);
  padding: var(--space-lg);
  transition: box-shadow var(--transition-fast);
  position: relative;
}
.about-tech-card:hover {
  box-shadow: var(--shadow-heavy);
}
.about-tech-icon {
  font-size: 1.5rem;
  color: var(--clr-primary-dark-gold);
  display: inline-block;
  margin-bottom: var(--space-sm);
}
.about-tech-card-title {
  font-family: var(--font-heading);
  font-weight: 700;
  font-size: 1.125rem;
  color: var(--clr-text-off-white);
  margin-bottom: var(--space-sm);
}
.about-tech-card p {
  color: var(--clr-text-muted-gold);
  line-height: 1.6;
  font-size: 0.95rem;
}
.about-tech-img {
  max-width: 100%;
  height: auto;
  display: block;
  margin-top: var(--space-sm);
  border: 1px solid var(--clr-border-olive);
}

/* 使命区域（第二层） */
.about-mission {
  padding: var(--space-2xl) var(--space-lg);
  background: var(--clr-bg-dark-rock);
  border-top: var(--border-thick) solid var(--clr-border-olive);
}
.about-mission-frame {
  max-width: 800px;
  margin: 0 auto;
  text-align: center;
  position: relative;
}
.about-mission-border {
  height: var(--border-thick);
  width: 120px;
  background: var(--clr-accent-neon-orange);
  margin: 0 auto var(--space-lg);
}
.about-mission-title {
  border-bottom: none;
  margin-left: auto;
  margin-right: auto;
}
.about-mission-text {
  font-family: var(--font-body);
  line-height: 1.8;
  color: var(--clr-text-off-white);
  max-width: 700px;
  margin: 0 auto;
  font-size: 1.05rem;
}

/* 信任声明 */
.about-trust {
  display: flex;
  align-items: center;
  gap: var(--space-sm);
  padding: var(--space-md) var(--space-lg);
  background: var(--clr-surface-dark-green);
  border-top: 1px solid var(--clr-border-olive);
  max-width: var(--max-width);
  margin: 0 auto;
  box-sizing: border-box;
}
.about-trust-icon {
  font-size: 1.25rem;
  color: var(--clr-primary-dark-gold);
}
.about-trust .trust-statement {
  font-family: var(--font-body);
  font-style: italic;
  font-size: 0.9rem;
  margin: 0;
  color: var(--clr-text-muted-gold);
}

/* 移动端优先 & 桌面响应 */
@media (min-width: 768px) {
  .about-hero-content {
    padding: var(--space-2xl) var(--space-xl);
  }
  .about-hero-scale {
    height: 160px;
  }
  .about-timeline-list {
    padding-left: 32px;
  }
  .about-timeline-list::before {
    left: 32px;
  }
  .about-timeline-item {
    padding-left: calc(48px + var(--space-md));
  }
  .about-timeline-marker {
    width: 20px;
    height: 20px;
  }
  .about-tech-grid {
    grid-template-columns: repeat(2, 1fr);
  }
  .about-tech-card-wide {
    grid-column: 1 / -1;
  }
}

@media (min-width: 1024px) {
  .about-hero-content {
    padding: var(--space-2xl) var(--space-2xl);
  }
  .about-hero-scale {
    height: 200px;
  }
  .about-tech-grid {
    grid-template-columns: repeat(3, 1fr);
  }
  .about-tech-card-wide {
    grid-column: span 2;
  }
  .about-mission-frame {
    max-width: 900px;
  }
}