.page-about {
  --timeline-line-color: var(--color-accent);
  --timeline-dot-size: 16px;
  --timeline-line-width: 3px;
  font-family: var(--font-body);
}

/* 面包屑基于 container 样式，已在全局定义 */
.page-about .breadcrumb {
  padding: 1rem 0;
  border-bottom: var(--border-width) solid var(--color-border);
  margin-bottom: 0;
}

/* 章节系统 */
.page-about .section-number-group {
  display: flex;
  flex-direction: column;
  gap: 1.5rem;
  padding: 2rem 1rem;
  position: relative;
}

@media (min-width: 768px) {
  .page-about .section-number-group {
    flex-direction: row;
    align-items: flex-start;
    gap: 3rem;
    padding: 3rem 1rem;
  }
}

.page-about .section-number {
  font-family: var(--font-heading);
  font-weight: 800;
  font-size: 5rem;
  line-height: 1;
  color: var(--color-highlight);
  letter-spacing: -2px;
  flex-shrink: 0;
  min-width: 80px;
}

@media (min-width: 768px) {
  .page-about .section-number {
    font-size: 6rem;
    min-width: 120px;
  }
}

.page-about .section-content-block {
  flex: 1;
  max-width: 900px;
}

.page-about .section-content-block h1,
.page-about .section-content-block h2 {
  font-family: var(--font-heading);
  font-weight: 800;
  text-transform: uppercase;
  letter-spacing: 1px;
  margin: 0 0 0.5rem;
}

.page-about .card.bg-alt {
  background: var(--color-bg-alt);
  border: var(--border-width) solid var(--color-border);
  padding: 1.5rem;
}

.page-about .card.bg-alt .card-body {
  font-size: 1rem;
  line-height: 1.6;
  color: var(--color-text-secondary);
}

/* 核心价值卡 */
.page-about .value-card {
  background: var(--color-bg);
  border: var(--border-width) solid var(--color-border);
  padding: 1.25rem;
  transition: background var(--transition-speed) ease-in-out, border-color var(--transition-speed) ease-in-out;
}

.page-about .value-card:hover,
.page-about .value-card[data-active="true"] {
  background: var(--color-bg-alt);
  border-color: var(--color-accent);
}

.page-about .value-card .card-title {
  display: flex;
  align-items: center;
  gap: 0.5rem;
  margin-bottom: 0.75rem;
}

.page-about .value-card .num-accent {
  font-family: var(--font-heading);
  font-weight: 800;
  font-size: 1.25rem;
  color: var(--color-accent);
}

.page-about .value-card .value-gold {
  font-family: var(--font-heading);
  font-weight: 700;
  color: var(--color-highlight);
  text-transform: uppercase;
  letter-spacing: 1px;
}

.page-about .value-card .card-body p {
  font-size: 0.95rem;
  color: var(--color-text-secondary);
  line-height: 1.5;
}

/* 时间线 */
.page-about .timeline {
  position: relative;
  padding-left: calc(var(--timeline-dot-size) + 1.5rem);
}

@media (min-width: 768px) {
  .page-about .timeline {
    padding-left: calc(var(--timeline-dot-size) + 2.5rem);
  }
}

.page-about .timeline::before {
  content: '';
  position: absolute;
  left: calc(var(--timeline-dot-size) / 2);
  top: 0;
  bottom: 0;
  width: var(--timeline-line-width);
  background: var(--timeline-line-color);
  border-radius: 2px;
}

.page-about .timeline-item {
  position: relative;
  margin-bottom: 2rem;
  padding-left: 1rem;
}

.page-about .timeline-item:last-child {
  margin-bottom: 0;
}

.page-about .timeline-dot {
  position: absolute;
  left: calc(-1 * (var(--timeline-dot-size) + 1.5rem));
  top: 0.25rem;
  width: var(--timeline-dot-size);
  height: var(--timeline-dot-size);
  background: var(--color-accent);
  border: 3px solid var(--color-primary);
  border-radius: 50%;
  z-index: 2;
  transition: background var(--transition-speed) ease-in-out, transform var(--transition-speed) ease-in-out;
}

.page-about .timeline-item:hover .timeline-dot,
.page-about .timeline-item[data-active="true"] .timeline-dot {
  background: var(--color-highlight);
  transform: scale(1.2);
}

.page-about .timeline-content {
  background: transparent;
  padding: 0.5rem 0;
  cursor: default;
}

.page-about .timeline-content h3 {
  font-family: var(--font-heading);
  font-weight: 700;
  font-size: 1.25rem;
  text-transform: uppercase;
  letter-spacing: 1px;
  margin: 0 0 0.25rem;
}

.page-about .timeline-content .caption {
  color: var(--color-text-secondary);
  font-size: 0.9rem;
}

.page-about .timeline-detail {
  margin-top: 0.5rem;
  padding: 0.75rem;
  background: var(--color-bg-alt);
  border-left: 3px solid var(--color-accent);
  display: none;
  max-height: 0;
  overflow: hidden;
  transition: max-height var(--transition-speed) ease-in-out, opacity var(--transition-speed) ease-in-out;
  opacity: 0;
}

.page-about .timeline-item[data-active="true"] .timeline-detail {
  display: block;
  max-height: 300px;
  opacity: 1;
}

.page-about .timeline-detail p {
  font-size: 0.95rem;
  color: var(--color-text);
  line-height: 1.5;
}

/* 底部行动区块 */
.page-about .accent-bg-block {
  background: var(--color-primary);
  border: none;
  margin-top: 0;
}

.page-about .accent-bg-block .section-content-block {
  max-width: 100%;
}

.page-about .accent-bg-block h2 {
  font-size: 2rem;
}

.page-about .accent-bg-block .btn {
  display: inline-block;
  padding: 0.75rem 1.5rem;
  font-family: var(--font-heading);
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 1px;
  border: none;
  border-radius: var(--border-radius);
  transition: background var(--transition-speed) ease-in-out, transform var(--transition-speed) ease-in-out;
  text-decoration: none;
}

.page-about .btn-primary {
  background: var(--color-accent);
  color: var(--color-bg);
}

.page-about .btn-primary:hover {
  background: var(--color-accent-hover);
  transform: translateY(-2px);
}

.page-about .btn-accent {
  background: var(--color-highlight);
  color: var(--color-primary);
}

.page-about .btn-accent:hover {
  background: #e6c200;
  transform: translateY(-2px);
}

.page-about .ml-1 {
  margin-left: 1rem;
}

/* 栅格响应式辅助 */
@media (min-width: 768px) {
  .page-about .grid-2-md {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 1rem;
  }
}

@media (max-width: 767px) {
  .page-about .grid-2-md {
    display: flex;
    flex-direction: column;
    gap: 1rem;
  }

  .page-about .section-number {
    font-size: 3rem;
  }

  .page-about .accent-bg-block .btn {
    display: block;
    width: 100%;
    margin: 0.5rem 0;
  }

  .page-about .ml-1 {
    margin-left: 0;
  }
}

/* 图片占位适配 */
.page-about .img-frame {
  display: flex;
  align-items: center;
  justify-content: center;
  background: var(--color-bg-alt);
  overflow: hidden;
  max-width: 100%;
}

.page-about .img-frame img {
  max-width: 100%;
  height: auto;
  object-fit: cover;
  display: block;
}

.page-about .text-center {
  text-align: center;
}

.page-about .mt-3 {
  margin-top: 2rem;
}

.page-about .py-3 {
  padding-top: 2rem;
  padding-bottom: 2rem;
}