/* ===== 页面专属样式: .page-about ===== */
.page-about {
  --about-timeline-width: 260px;
  --about-gold-line: var(--gold);
  --about-bg-dark: var(--deep-green);
  --about-bg-light: var(--white);
  --about-card-bg: var(--light-green-bg);
  --about-accent: var(--gold);
  --about-text-light: var(--white);
  --about-text-dark: var(--charcoal);
  --about-text-muted: var(--grey-text);
  --about-radius: var(--radius-md);
  --about-transition: var(--transition-med);

  display: block;
  width: 100%;
  max-width: var(--max-width);
  margin: 0 auto;
  padding: 0 16px 40px;
  color: var(--about-text-dark);
  font-family: var(--font-body);
  line-height: 1.6;
}

/* ---- 面包屑 ---- */
.page-about .breadcrumb {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 6px;
  padding: 12px 0 8px;
  font-size: 13px;
  color: var(--about-text-muted);
}
.page-about .breadcrumb a {
  color: var(--about-text-muted);
  text-decoration: none;
  transition: color var(--transition-fast);
}
.page-about .breadcrumb a:hover,
.page-about .breadcrumb a:focus-visible {
  color: var(--gold);
  outline: none;
}
.page-about .breadcrumb .sep {
  color: var(--gold);
  font-weight: 700;
}
.page-about .breadcrumb [aria-current="page"] {
  color: var(--deep-green);
  font-weight: 600;
}

/* ---- 左右分屏容器 ---- */
.page-about .about-split {
  display: flex;
  flex-direction: column;
  gap: 24px;
  margin-top: 8px;
}

/* ===== 左栏: 时间轴 ===== */
.page-about .about-timeline {
  position: relative;
  flex: 0 0 auto;
  background: var(--about-bg-dark);
  border-radius: var(--about-radius);
  padding: 24px 20px 28px;
  color: var(--about-text-light);
  clip-path: polygon(0 0, 100% 0, calc(100% - 12px) 100%, 0 100%);
  transition: box-shadow var(--about-transition);
}
.page-about .about-timeline:hover {
  box-shadow: 0 8px 28px rgba(11, 78, 46, 0.30);
}

.page-about .timeline-header {
  display: flex;
  flex-direction: column;
  margin-bottom: 20px;
}
.page-about .timeline-header .index-deco {
  font-family: var(--font-mono);
  font-size: 14px;
  color: var(--gold);
  letter-spacing: 2px;
}
.page-about .timeline-header .timeline-title {
  font-family: var(--font-heading);
  font-size: 32px;
  font-weight: 700;
  line-height: 1.1;
  margin: 4px 0 0;
  color: var(--white);
  text-transform: uppercase;
  letter-spacing: 2px;
}
.page-about .timeline-header .timeline-sub {
  font-size: 14px;
  color: rgba(255, 255, 255, 0.65);
  margin: 2px 0 0;
  letter-spacing: 1px;
}

/* 时间轴连线 (垂直装饰) */
.page-about .timeline-track {
  position: absolute;
  left: 52px;
  top: 100px;
  bottom: 24px;
  width: 2px;
  background: linear-gradient(to bottom, var(--gold) 0%, rgba(255, 215, 0, 0.20) 100%);
  border-radius: 1px;
  pointer-events: none;
}

/* 节点列表 */
.page-about .timeline-nodes {
  list-style: none;
  margin: 0;
  padding: 0;
  display: flex;
  flex-direction: column;
  gap: 28px;
  position: relative;
  z-index: 2;
}

.page-about .timeline-node {
  position: relative;
  display: flex;
  flex-direction: column;
  align-items: flex-start;
  gap: 4px;
}

/* 节点链接 */
.page-about .node-link {
  display: inline-flex;
  align-items: center;
  gap: 12px;
  text-decoration: none;
  color: var(--about-text-light);
  transition: all var(--transition-fast);
  padding: 6px 12px 6px 0;
  border-radius: var(--radius-sm);
  cursor: pointer;
}
.page-about .node-link:hover,
.page-about .node-link:focus-visible {
  color: var(--gold);
  outline: none;
  transform: translateX(4px);
}
.page-about .node-link:focus-visible {
  outline: 2px solid var(--gold);
  outline-offset: 2px;
}

.page-about .node-number {
  font-family: var(--font-mono);
  font-size: 18px;
  font-weight: 600;
  color: var(--gold);
  width: 28px;
  text-align: right;
  flex-shrink: 0;
}
.page-about .node-label {
  font-family: var(--font-heading);
  font-size: 18px;
  font-weight: 500;
  text-transform: uppercase;
  letter-spacing: 1px;
}

/* 节点小圆点 (装饰) */
.page-about .timeline-node::before {
  content: '';
  position: absolute;
  left: -38px;
  top: 12px;
  width: 10px;
  height: 10px;
  border-radius: 50%;
  background: var(--gold);
  border: 2px solid var(--about-bg-dark);
  box-shadow: 0 0 0 2px var(--gold);
  transition: transform var(--transition-fast), box-shadow var(--transition-fast);
  pointer-events: none;
}
.page-about .timeline-node:hover::before {
  transform: scale(1.35);
  box-shadow: 0 0 0 3px var(--gold), 0 0 12px rgba(255, 215, 0, 0.50);
}

/* 节点 tooltip */
.page-about .node-tooltip {
  position: absolute;
  left: 0;
  top: calc(100% + 4px);
  background: var(--gold);
  color: var(--charcoal);
  font-size: 13px;
  font-weight: 500;
  padding: 6px 12px;
  border-radius: var(--radius-sm);
  white-space: nowrap;
  max-width: 240px;
  opacity: 0;
  transform: translateY(-4px);
  pointer-events: none;
  transition: opacity var(--transition-fast), transform var(--transition-fast);
  z-index: 10;
  box-shadow: 0 4px 12px rgba(0, 0, 0, 0.15);
}
.page-about .node-tooltip::before {
  content: '';
  position: absolute;
  top: -6px;
  left: 20px;
  width: 0;
  height: 0;
  border-left: 6px solid transparent;
  border-right: 6px solid transparent;
  border-bottom: 6px solid var(--gold);
}
.page-about .timeline-node:hover .node-tooltip,
.page-about .timeline-node:focus-within .node-tooltip {
  opacity: 1;
  transform: translateY(0);
}

/* ===== 右栏: 内容区 ===== */
.page-about .about-content {
  flex: 1 1 auto;
  display: flex;
  flex-direction: column;
  gap: 36px;
  min-width: 0;
}

/* 内容区块通用 */
.page-about .content-section {
  scroll-margin-top: 80px;
}

.page-about .section-header {
  display: flex;
  align-items: baseline;
  gap: 12px;
  margin-bottom: 16px;
  border-bottom: 2px solid var(--gold);
  padding-bottom: 8px;
}
.page-about .section-number {
  font-family: var(--font-mono);
  font-size: 20px;
  font-weight: 700;
  color: var(--gold);
  letter-spacing: 1px;
}
.page-about .section-title {
  font-family: var(--font-heading);
  font-size: 28px;
  font-weight: 700;
  margin: 0;
  color: var(--deep-green);
  text-transform: uppercase;
  letter-spacing: 1px;
}

.page-about .section-body {
  display: flex;
  flex-direction: column;
  gap: 16px;
}
.page-about .section-lead {
  font-size: 17px;
  line-height: 1.7;
  color: var(--about-text-dark);
  font-weight: 400;
}

/* 图片容器 */
.page-about .section-image {
  width: 100%;
  border-radius: var(--about-radius);
  overflow: hidden;
  background: var(--light-green-bg);
}
.page-about .img-responsive {
  display: block;
  width: 100%;
  max-width: 100%;
  height: auto;
  object-fit: cover;
}
.page-about .section-image .img-responsive {
  max-height: 360px;
  object-position: center;
}

/* details / summary */
.page-about .section-details {
  margin-top: 4px;
  border: 1px solid rgba(11, 78, 46, 0.15);
  border-radius: var(--radius-sm);
  padding: 0 12px;
  transition: all var(--transition-fast);
}
.page-about .section-details[open] {
  padding: 12px;
  background: var(--gold-light);
  border-color: var(--gold);
}
.page-about .section-details summary {
  cursor: pointer;
  font-weight: 600;
  font-size: 14px;
  color: var(--deep-green);
  padding: 8px 0;
  transition: color var(--transition-fast);
  user-select: none;
}
.page-about .section-details summary:hover,
.page-about .section-details summary:focus-visible {
  color: var(--gold);
  outline: none;
}
.page-about .section-details[open] summary {
  padding: 0 0 8px;
  border-bottom: 1px solid rgba(11, 78, 46, 0.10);
  margin-bottom: 8px;
}
.page-about .section-details p {
  font-size: 15px;
  line-height: 1.6;
  color: var(--about-text-dark);
  margin: 8px 0 0;
}

/* ---- 功能亮点子区块 ---- */
.page-about .feature-block {
  background: var(--about-card-bg);
  border-radius: var(--about-radius);
  padding: 20px;
  border-left: 4px solid var(--gold);
  transition: box-shadow var(--transition-fast), transform var(--transition-fast);
}
.page-about .feature-block:hover {
  box-shadow: 0 4px 16px rgba(11, 78, 46, 0.12);
  transform: translateY(-2px);
}
.page-about .feature-block + .feature-block {
  margin-top: 20px;
}
.page-about .feature-badge {
  display: inline-block;
  font-size: 12px;
  font-weight: 600;
  letter-spacing: 0.5px;
  margin-bottom: 6px;
}
.page-about .feature-title {
  font-family: var(--font-heading);
  font-size: 20px;
  font-weight: 600;
  margin: 0 0 8px;
  color: var(--deep-green);
}
.page-about .feature-block p {
  font-size: 15px;
  line-height: 1.65;
  color: var(--about-text-muted);
  margin: 0;
}
.page-about .feature-block .section-details {
  margin-top: 12px;
  background: var(--white);
}

.page-about .feature-actions {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
  margin-top: 8px;
}

/* 按钮 (复用全局 btn 基类) */
.page-about .btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  padding: 10px 24px;
  font-family: var(--font-body);
  font-size: 14px;
  font-weight: 600;
  border-radius: var(--radius-sm);
  text-decoration: none;
  transition: all var(--transition-fast);
  cursor: pointer;
  border: 2px solid transparent;
  line-height: 1.2;
}
.page-about .btn-gold {
  background: var(--gold);
  color: var(--charcoal);
  border-color: var(--gold);
}
.page-about .btn-gold:hover,
.page-about .btn-gold:focus-visible {
  background: #e6c200;
  border-color: #e6c200;
  transform: translateY(-1px);
  box-shadow: 0 4px 12px rgba(255, 215, 0, 0.35);
  outline: none;
}
.page-about .btn-outline {
  background: transparent;
  color: var(--deep-green);
  border-color: var(--deep-green);
}
.page-about .btn-outline:hover,
.page-about .btn-outline:focus-visible {
  background: var(--deep-green);
  color: var(--white);
  transform: translateY(-1px);
  outline: none;
}

/* ---- 持续优化 ---- */
.page-about .optimization-layout {
  flex-direction: column;
  gap: 20px;
}
.page-about .optimization-text {
  display: flex;
  flex-direction: column;
  gap: 14px;
}
.page-about .optimization-image {
  width: 100%;
  max-width: 300px;
  border-radius: var(--about-radius);
  overflow: hidden;
  background: var(--light-green-bg);
}
.page-about .optimization-image .img-responsive {
  max-height: 420px;
  object-position: top center;
}

/* ---- 信任声明 ---- */
.page-about .about-trust {
  margin-top: 12px;
  padding: 24px 20px;
  background: linear-gradient(135deg, var(--deep-green) 0%, #0a3d24 100%);
  border-radius: var(--about-radius);
  color: var(--white);
  text-align: center;
}
.page-about .trust-text {
  font-family: var(--font-heading);
  font-size: 22px;
  font-weight: 600;
  letter-spacing: 1px;
  margin: 0 0 12px;
  color: var(--gold);
}
.page-about .trust-contact {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  justify-content: center;
  gap: 8px 16px;
  font-size: 15px;
  margin-bottom: 12px;
}
.page-about .contact-label {
  font-weight: 600;
  color: rgba(255, 255, 255, 0.75);
  font-size: 13px;
  letter-spacing: 0.5px;
}
.page-about .contact-email {
  color: var(--gold);
  text-decoration: none;
  font-weight: 600;
  transition: color var(--transition-fast);
}
.page-about .contact-email:hover,
.page-about .contact-email:focus-visible {
  color: var(--white);
  outline: none;
}
.page-about .contact-note {
  font-size: 13px;
  color: rgba(255, 255, 255, 0.60);
}
.page-about .trust-links {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  font-size: 14px;
}
.page-about .trust-links a {
  color: rgba(255, 255, 255, 0.85);
  text-decoration: none;
  transition: color var(--transition-fast);
}
.page-about .trust-links a:hover,
.page-about .trust-links a:focus-visible {
  color: var(--gold);
  outline: none;
}
.page-about .trust-links .sep {
  color: rgba(255, 255, 255, 0.35);
}

/* ---- 底部装饰 ---- */
.page-about .about-bottom-deco {
  display: flex;
  justify-content: center;
  align-items: center;
  padding: 32px 0 16px;
  opacity: 0.60;
}
.page-about .about-bottom-deco .deco-image {
  width: 120px;
  height: auto;
  max-width: 100%;
  border-radius: var(--radius-sm);
}

/* ======================================================
   移动端优先基础样式 (默认 < 768px)
   上下结构：时间轴在上，内容在下
   ====================================================== */
@media (max-width: 767.98px) {
  .page-about {
    padding: 0 12px 32px;
  }
  .page-about .about-split {
    flex-direction: column;
    gap: 20px;
  }
  .page-about .about-timeline {
    clip-path: polygon(0 0, 100% 0, calc(100% - 8px) 100%, 0 100%);
    padding: 20px 16px 24px;
  }
  .page-about .timeline-header .timeline-title {
    font-size: 26px;
  }
  .page-about .timeline-track {
    left: 40px;
    top: 90px;
  }
  .page-about .timeline-nodes {
    gap: 22px;
  }
  .page-about .node-number {
    font-size: 16px;
    width: 24px;
  }
  .page-about .node-label {
    font-size: 16px;
  }
  .page-about .timeline-node::before {
    left: -31px;
    top: 10px;
    width: 8px;
    height: 8px;
  }
  .page-about .node-tooltip {
    font-size: 12px;
    padding: 4px 10px;
    max-width: 200px;
    white-space: normal;
  }
  .page-about .section-title {
    font-size: 22px;
  }
  .page-about .section-number {
    font-size: 17px;
  }
  .page-about .feature-title {
    font-size: 18px;
  }
  .page-about .trust-text {
    font-size: 19px;
  }
  .page-about .trust-contact {
    flex-direction: column;
    gap: 4px;
  }
  .page-about .feature-actions {
    flex-direction: column;
  }
  .page-about .feature-actions .btn {
    width: 100%;
    text-align: center;
  }
  .page-about .optimization-image {
    max-width: 100%;
  }
  .page-about .about-bottom-deco .deco-image {
    width: 100px;
  }
}

/* ======================================================
   平板及以上 (>= 768px) → 左右分屏
   ====================================================== */
@media (min-width: 768px) {
  .page-about .about-split {
    flex-direction: row;
    align-items: flex-start;
    gap: 28px;
  }
  .page-about .about-timeline {
    position: sticky;
    top: 76px;
    z-index: 5;
    flex: 0 0 var(--about-timeline-width);
    max-height: calc(100vh - 100px);
    overflow-y: auto;
  }
  .page-about .about-content {
    flex: 1 1 calc(100% - var(--about-timeline-width) - 28px);
  }
  /* 节点 tooltip 在桌面端显示在右侧 */
  .page-about .node-tooltip {
    left: calc(100% + 16px);
    top: 50%;
    transform: translateY(-50%) translateX(-4px);
    white-space: nowrap;
  }
  .page-about .node-tooltip::before {
    top: 50%;
    left: -6px;
    transform: translateY(-50%);
    border-top: 6px solid transparent;
    border-bottom: 6px solid transparent;
    border-right: 6px solid var(--gold);
    border-left: none;
  }
  .page-about .timeline-node:hover .node-tooltip,
  .page-about .timeline-node:focus-within .node-tooltip {
    transform: translateY(-50%) translateX(0);
  }
  .page-about .section-image .img-responsive {
    max-height: 320px;
  }
  .page-about .optimization-layout {
    flex-direction: row;
    align-items: flex-start;
    gap: 24px;
  }
  .page-about .optimization-text {
    flex: 1 1 60%;
  }
  .page-about .optimization-image {
    flex: 0 0 200px;
  }
  .page-about .feature-actions {
    flex-direction: row;
  }
}

/* ======================================================
   宽屏桌面 (>= 992px)
   ====================================================== */
@media (min-width: 992px) {
  .page-about {
    padding: 0 24px 48px;
  }
  .page-about .about-timeline {
    flex-basis: 280px;
    padding: 28px 24px 32px;
  }
  .page-about .timeline-header .timeline-title {
    font-size: 36px;
  }
  .page-about .section-title {
    font-size: 32px;
  }
  .page-about .section-lead {
    font-size: 18px;
  }
  .page-about .feature-block {
    padding: 24px;
  }
  .page-about .about-trust {
    padding: 32px 40px;
  }
  .page-about .trust-text {
    font-size: 26px;
  }
  .page-about .about-bottom-deco .deco-image {
    width: 140px;
  }
}

/* ===== 辅助: 印刷与可访问性 ===== */
@media print {
  .page-about .about-timeline {
    clip-path: none;
    position: static;
    break-inside: avoid;
  }
  .page-about .node-tooltip {
    display: none;
  }
  .page-about .about-bottom-deco {
    display: none;
  }
  .page-about .feature-actions .btn {
    border: 1px solid #999;
    color: #000;
    background: none;
  }
}

/* 高对比度模式 */
@media (prefers-contrast: high) {
  .page-about {
    --about-text-dark: #000;
    --about-text-muted: #222;
  }
  .page-about .about-timeline {
    background: var(--charcoal);
  }
  .page-about .breadcrumb a {
    color: #000;
    text-decoration: underline;
  }
  .page-about .btn-outline {
    border-width: 3px;
  }
}

/* 减少动效偏好 */
@media (prefers-reduced-motion: reduce) {
  .page-about *,
  .page-about *::before,
  .page-about *::after {
    transition-duration: 0.01ms !important;
    animation-duration: 0.01ms !important;
    transform: none !important;
  }
  .page-about .node-tooltip {
    transition: opacity 0.01ms;
  }
}