.page-about {
  --timeline-line-color: var(--color-gold, #FFD700);
  --timeline-node-size: 24px;
  --section-padding: 3rem 1.5rem;
  --grid-gap: 1.5rem;
  color: var(--color-text, #111);
  background-color: var(--color-light, #F5F5F5);
  min-height: 100vh;
}

/* 移动端优先 */
.page-about__intro {
  position: relative;
  background: var(--color-dark, #1A1A1A);
  color: var(--color-white, #FFF);
  padding: 4rem 1.5rem 2rem;
  overflow: hidden;
}

.page-about__intro::before {
  content: '';
  position: absolute;
  top: 0; left: 0; right: 0; bottom: 0;
  background: linear-gradient(135deg, var(--color-blue, #004B87) 0%, var(--color-dark, #1A1A1A) 60%);
  opacity: 0.25;
  z-index: 0;
}

.page-about__intro .coordinate {
  position: relative;
  z-index: 1;
  display: block;
  font-family: var(--font-mono, 'Courier New', monospace);
  font-size: 0.75rem;
  color: var(--color-gold, #FFD700);
  letter-spacing: 0.1em;
  margin-bottom: 1rem;
}

.page-about__heading {
  position: relative;
  z-index: 1;
  font-family: var(--font-heading, 'Helvetica Neue', Arial, sans-serif);
  font-weight: 900;
  font-style: italic;
  font-size: clamp(2rem, 8vw, 4rem);
  margin: 0 0 0.5rem;
  line-height: 1;
  color: var(--color-red, #E30613);
  text-transform: uppercase;
}

.page-about__subhead {
  position: relative;
  z-index: 1;
  font-family: var(--font-body, 'Inter', Arial, sans-serif);
  font-size: 1.125rem;
  max-width: 35rem;
  line-height: 1.5;
  color: var(--color-white, #FFF);
}

.page-about__section-title {
  font-family: var(--font-heading, 'Helvetica Neue', Arial, sans-serif);
  font-weight: 900;
  font-style: italic;
  font-size: clamp(1.75rem, 5vw, 2.5rem);
  margin: 0 0 1.5rem;
  color: var(--color-dark, #1A1A1A);
  border-left: 4px solid var(--color-red, #E30613);
  padding-left: 0.75rem;
}

/* 我们的使命 */
.page-about__mission {
  display: flex;
  flex-direction: column;
  gap: var(--grid-gap);
  padding: var(--section-padding);
  max-width: var(--max-width, 1200px);
  margin: 0 auto;
}

.page-about__mission-content {
  flex: 1;
}

.page-about__mission-text {
  font-size: 1rem;
  line-height: 1.7;
  margin-bottom: 1rem;
}

.page-about__mission-image {
  flex-shrink: 0;
}

.page-about__mission-image img {
  max-width: 100%;
  height: auto;
  display: block;
  border: 2px solid var(--color-blue, #004B87);
}

/* 发展历程 */
.page-about__timeline {
  position: relative;
  padding: var(--section-padding);
  margin: 0 auto;
  max-width: var(--max-width, 1200px);
}

.page-about__timeline-bg {
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  height: 100%;
  overflow: hidden;
  z-index: 0;
  opacity: 0.1;
}

.page-about__timeline-bg img {
  width: 100%;
  height: 100%;
  object-fit: cover;
  object-position: center;
}

.page-about__timeline-title {
  position: relative;
  z-index: 1;
  color: var(--color-dark, #1A1A1A);
}

.page-about__timeline-list {
  position: relative;
  z-index: 1;
  list-style: none;
  margin: 0;
  padding: 0;
  display: flex;
  flex-direction: column;
  gap: 2rem;
  counter-reset: timeline-step;
}

.page-about__timeline-item {
  display: flex;
  gap: 1rem;
  align-items: flex-start;
  position: relative;
  counter-increment: timeline-step;
}

/* 竖线 */
.page-about__timeline-item:not(:last-child)::after {
  content: '';
  position: absolute;
  left: calc(var(--timeline-node-size) / 2 - 1px);
  top: var(--timeline-node-size);
  bottom: -2rem;
  width: 2px;
  background: var(--timeline-line-color);
  opacity: 0.5;
}

.page-about__timeline-marker {
  flex-shrink: 0;
  width: var(--timeline-node-size);
  height: var(--timeline-node-size);
  display: flex;
  align-items: center;
  justify-content: center;
  background: var(--color-gold, #FFD700);
  border-radius: 50%;
  position: relative;
  z-index: 2;
}

.page-about__timeline-marker img {
  border-radius: 50%;
  width: 100%;
  height: 100%;
  object-fit: cover;
}

/* 第二个、第三个节点用纯CSS金色圆点（无 img 时） */
.page-about__timeline-item:not(:first-child) .page-about__timeline-marker {
  background: var(--color-gold, #FFD700);
  box-shadow: 0 0 0 3px var(--color-dark, #1A1A1A);
}

.page-about__timeline-content {
  flex: 1;
  padding-top: 0.25rem;
}

.page-about__timeline-phase {
  font-family: var(--font-heading, 'Helvetica Neue', Arial, sans-serif);
  font-weight: 700;
  font-style: italic;
  font-size: 1.25rem;
  margin: 0 0 0.25rem;
  color: var(--color-dark, #1A1A1A);
}

.page-about__timeline-desc {
  font-size: 0.95rem;
  line-height: 1.6;
}

.page-about__timeline-footnote {
  margin-top: 2rem;
  font-style: italic;
  font-family: var(--font-body);
}

/* 品牌理念 */
.page-about__values {
  padding: var(--section-padding);
  max-width: var(--max-width, 1200px);
  margin: 0 auto;
  background: var(--color-dark, #1A1A1A);
  color: var(--color-white, #FFF);
}

.page-about__values .page-about__section-title {
  color: var(--color-white);
  border-left-color: var(--color-gold, #FFD700);
}

.page-about__values-grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: 2rem;
}

.page-about__values-item {
  padding: 1rem;
  border: 1px solid rgba(255,255,255,0.2);
  background: rgba(255,255,255,0.05);
}

.page-about__values-item .data-label {
  display: block;
  font-family: var(--font-mono, 'Courier New', monospace);
  color: var(--color-gold, #FFD700);
  font-weight: bold;
  font-size: 0.9rem;
  margin-bottom: 0.5rem;
  text-transform: uppercase;
}

.page-about__values-item p {
  font-size: 0.95rem;
  line-height: 1.6;
  margin: 0;
}

.page-about__values-cta {
  margin-top: 2rem;
  text-align: center;
}

.page-about__values-cta a {
  color: var(--color-gold);
  text-decoration: underline;
}

/* 桌面媒体查询 */
@media (min-width: 768px) {
  .page-about__intro {
    padding: 6rem 3rem 3rem;
  }

  .page-about__mission {
    flex-direction: row;
    align-items: center;
    gap: 2rem;
  }

  .page-about__mission-content {
    flex: 1 1 55%;
  }

  .page-about__mission-image {
    flex: 1 1 40%;
  }

  .page-about__timeline-list {
    padding-left: 2rem;
  }

  .page-about__timeline-item {
    gap: 1.5rem;
  }

  .page-about__values-grid {
    grid-template-columns: repeat(3, 1fr);
  }

  .page-about__values-item {
    padding: 1.5rem;
  }
}

/* 保证内部链接颜色 */
.page-about a {
  color: var(--color-blue, #004B87);
  text-decoration: underline;
  transition: color 0.2s;
}

.page-about a:hover,
.page-about a:focus {
  color: var(--color-red, #E30613);
}

.page-about {
  --color-text: var(--color-white);
}