.page-about {
  font-family: var(--font-body);
  color: var(--text-primary);
  background: var(--bg-light);
  max-width: var(--content-width);
  margin: 0 auto;
  padding: 0 var(--grid-gap);
}

/* 面包屑 */
.page-about .breadcrumb {
  padding: 1rem 0;
  font-size: 0.875rem;
  color: var(--text-secondary);
}

.page-about .breadcrumb a {
  color: var(--primary);
  text-decoration: underline;
}

/* 首屏 */
.page-about .hero {
  padding: 3rem 0 2rem;
  border-bottom: 4px solid var(--primary);
  margin-bottom: var(--grid-gap);
}

.page-about .hero h1 {
  font-family: var(--font-heading);
  font-weight: 900;
  font-size: 3.5rem;
  line-height: 1.1;
  margin: 0;
  color: var(--text-primary);
  letter-spacing: 0.02em;
}

.page-about .hero__subtitle {
  font-size: 1.125rem;
  color: var(--text-secondary);
  margin-top: 1rem;
  max-width: 600px;
}

/* 通用section */
.page-about .section {
  padding: 3rem 0;
}

.page-about .section h2 {
  font-family: var(--font-heading);
  font-weight: 900;
  font-size: 2.25rem;
  margin: 0 0 1.5rem;
  position: relative;
}

/* 我们的服务 */
.page-about #services .section__content {
  display: flex;
  gap: 2rem;
  align-items: flex-start;
}

.page-about #services .section__content p {
  flex: 1;
  font-size: 1rem;
  line-height: 1.6;
}

.page-about #services .section__content img {
  width: 100%;
  max-width: 600px;
  height: auto;
  border: 4px solid var(--border);
  box-shadow: var(--shadow);
}

/* V4版更新日志 */
.page-about .section--updates h2 {
  display: flex;
  align-items: baseline;
  gap: 0.5rem;
}

.page-about .vert-label {
  writing-mode: vertical-rl;
  font-size: 0.875rem;
  font-weight: 900;
  color: var(--primary);
  letter-spacing: 0.2em;
}

.page-about .updates__banner {
  width: 100%;
  max-width: 1200px;
  height: auto;
  border: 4px solid var(--border);
  box-shadow: var(--shadow);
  margin-bottom: 2rem;
}

/* 时间轴 */
.page-about .timeline {
  list-style: none;
  padding: 0;
  margin: 0;
}

.page-about .timeline__item {
  position: relative;
  margin-bottom: 2rem;
  padding: 0 0 0 2.5rem; /* 为圆点和竖条留空间 */
  border-left: 4px solid var(--primary);
}

.page-about .timeline__item::before {
  content: attr(data-version);
  position: absolute;
  left: -1.5rem;  /* 置于左边框外侧 */
  top: 1rem;
  width: 2.5rem;
  height: 2.5rem;
  background: var(--primary);
  color: #fff;
  font-family: var(--font-mono);
  font-weight: 900;
  font-size: 0.875rem;
  display: flex;
  align-items: center;
  justify-content: center;
  border-radius: 50%;
  z-index: 1;
}

/* 提示框 */
.page-about .timeline__item[data-desc]::after {
  content: attr(data-desc);
  position: absolute;
  left: 3rem;
  top: -0.5rem;
  background: var(--bg-dark);
  color: #fff;
  padding: 0.5rem 1rem;
  border-radius: 4px;
  font-size: 0.75rem;
  white-space: nowrap;
  opacity: 0;
  pointer-events: none;
  transition: opacity var(--transition);
  z-index: 10;
}

.page-about .timeline__item[data-desc]:hover::after {
  opacity: 1;
}

/* details卡片 */
.page-about .timeline__item details {
  background: #fff;
  border: 2px solid var(--border);
  box-shadow: var(--shadow);
  padding: 1rem;
  margin: 0.5rem 0 0.5rem 0;
  cursor: pointer;
}

.page-about .timeline__item details summary {
  font-family: var(--font-heading);
  font-weight: 900;
  font-size: 1.125rem;
  color: var(--text-primary);
  outline: none;
  list-style: none;
}

.page-about .timeline__item details summary::-webkit-details-marker {
  display: none;
}

.page-about .timeline__item details summary::before {
  content: '+ ';
  color: var(--primary);
}

.page-about .timeline__item details[open] summary::before {
  content: '- ';
}

.page-about .timeline__item details p {
  margin: 1rem 0 0;
  color: var(--text-secondary);
  line-height: 1.6;
}

/* 品牌承诺 */
.page-about .section--commitment .commitment__content {
  display: flex;
  gap: 2rem;
  align-items: center;
}

.page-about .commitment__visual {
  width: 100%;
  max-width: 400px;
  height: auto;
  border: 4px solid var(--secondary);
  box-shadow: var(--shadow);
  border-radius: 50%;
  object-fit: cover;
}

.page-about .commitment__text {
  flex: 1;
}

.page-about .commitment__text p {
  font-size: 1rem;
  line-height: 1.6;
  margin-bottom: 1rem;
}

.page-about .commitment__text a {
  color: var(--primary);
  text-decoration: underline;
}

/* 响应式 */
@media (max-width: 768px) {
  .page-about .hero h1 {
    font-size: 2.5rem;
  }

  .page-about #services .section__content {
    flex-direction: column;
  }

  .page-about .section--commitment .commitment__content {
    flex-direction: column;
  }

  .page-about .timeline__item {
    padding-left: 2rem;
    border-left-width: 4px;
  }

  .page-about .timeline__item::before {
    left: -1.25rem;
    width: 2rem;
    height: 2rem;
    font-size: 0.75rem;
  }

  .page-about .timeline__item[data-desc]::after {
    left: 2.5rem;
    white-space: normal;
    max-width: 180px;
  }

  .page-about .updates__banner {
    display: none; /* 移动端隐藏横幅图片，减少占用 */
  }
}