.page-about {
  --page-max-width: 1120px;
  --page-gap: 2.5rem;
  --page-section-spacing: 4rem;
  --page-card-radius: 12px;
  --page-flip-speed: 0.5s;

  max-width: var(--page-max-width);
  margin: 0 auto;
  padding: 1.5rem 1.25rem 3rem;
  font-family: var(--font-primary);
  color: var(--color-text);
}

/* ---------- 面包屑 ---------- */
.page-about .breadcrumb {
  display: flex;
  align-items: center;
  gap: 0.5rem;
  font-size: 0.85rem;
  color: var(--color-text-secondary);
  margin-bottom: 2rem;
  letter-spacing: 0.02em;
}
.page-about .breadcrumb a {
  color: var(--color-gold);
  text-decoration: none;
  transition: color var(--transition);
}
.page-about .breadcrumb a:hover,
.page-about .breadcrumb a:focus-visible {
  color: var(--color-hover);
  outline: 2px solid var(--color-gold);
  outline-offset: 2px;
}
.page-about .breadcrumb-sep {
  color: var(--color-border);
  font-size: 0.75rem;
}
.page-about .breadcrumb [aria-current="page"] {
  color: var(--color-text-secondary);
  font-weight: 400;
}

/* ---------- 首屏：我们的故事 ---------- */
.page-about .story-hero {
  display: flex;
  flex-direction: column;
  gap: 1.75rem;
  margin-bottom: var(--page-section-spacing);
}
.page-about .story-hero__text {
  order: 2;
}
.page-about .story-hero__visual {
  order: 1;
}
.page-about .story-hero__heading {
  font-size: 2.2rem;
  font-weight: 700;
  color: var(--color-gold);
  letter-spacing: -0.02em;
  line-height: 1.1;
  margin: 0 0 0.5rem;
}
.page-about .story-hero__subtitle {
  font-size: 1.1rem;
  font-weight: 400;
  color: var(--color-text-secondary);
  margin: 0 0 1.25rem;
  letter-spacing: 0.01em;
  line-height: 1.4;
}
.page-about .story-hero__body {
  font-size: 1rem;
  line-height: 1.7;
  color: var(--color-text);
  margin: 0 0 1.5rem;
  max-width: 540px;
}
.page-about .story-hero__accent-line {
  width: 60px;
  height: 3px;
  background: var(--color-gold);
  border-radius: 2px;
}
.page-about .story-hero__img {
  display: block;
  width: 100%;
  max-width: 100%;
  height: auto;
  border-radius: var(--page-card-radius);
  box-shadow: var(--shadow-card);
  object-fit: cover;
  aspect-ratio: 600 / 400;
}

/* ---------- 时间线 ---------- */
.page-about .timeline {
  margin-bottom: var(--page-section-spacing);
}
.page-about .timeline__heading {
  font-size: 1.8rem;
  font-weight: 700;
  color: var(--color-gold);
  letter-spacing: -0.01em;
  margin: 0 0 1.75rem;
  line-height: 1.2;
}
.page-about .timeline__track {
  display: flex;
  flex-direction: column;
  gap: 1rem;
}
.page-about .timeline__node {
  background: var(--color-card);
  border-radius: var(--page-card-radius);
  border: 1px solid var(--color-border);
  overflow: hidden;
  transition: border-color var(--transition), box-shadow var(--transition);
}
.page-about .timeline__node:hover,
.page-about .timeline__node:focus-within {
  border-color: var(--color-gold);
  box-shadow: 0 2px 16px var(--color-gold-dim);
}
.page-about .timeline__node-title {
  list-style: none;
  display: flex;
  align-items: center;
  gap: 0.75rem;
  padding: 1.1rem 1.25rem;
  font-weight: 600;
  font-size: 1.05rem;
  color: var(--color-text);
  cursor: pointer;
  user-select: none;
  transition: color var(--transition);
  position: relative;
}
.page-about .timeline__node-title::-webkit-details-marker {
  display: none;
}
.page-about .timeline__node-title::before {
  content: "▸";
  display: inline-block;
  font-size: 1.2rem;
  color: var(--color-gold);
  transition: transform var(--transition);
  flex-shrink: 0;
}
.page-about .timeline__node[open] .timeline__node-title::before {
  transform: rotate(90deg);
}
.page-about .timeline__node-title::after {
  content: "";
  flex: 1;
  height: 1px;
  background: var(--color-border);
  margin-left: 0.75rem;
}
.page-about .timeline__node-desc {
  padding: 0 1.25rem 1.1rem;
  margin: 0;
  font-size: 0.95rem;
  line-height: 1.6;
  color: var(--color-text-secondary);
}

/* ---------- 使命与愿景（翻转卡片） ---------- */
.page-about .ideals {
  margin-bottom: var(--page-section-spacing);
}
.page-about .ideals__heading {
  font-size: 1.8rem;
  font-weight: 700;
  color: var(--color-gold);
  letter-spacing: -0.01em;
  margin: 0 0 1.75rem;
  line-height: 1.2;
}
.page-about .ideals__grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: 1.5rem;
}
.page-about .flip-card {
  perspective: 800px;
  outline: none;
  min-height: 240px;
}
.page-about .flip-card__inner {
  position: relative;
  width: 100%;
  height: 100%;
  min-height: 240px;
  transition: transform var(--page-flip-speed) cubic-bezier(0.23, 1, 0.32, 1);
  transform-style: preserve-3d;
  border-radius: var(--page-card-radius);
  box-shadow: var(--shadow-card);
}
.page-about .flip-card:hover .flip-card__inner,
.page-about .flip-card:focus-within .flip-card__inner {
  transform: rotateY(180deg);
}
.page-about .flip-card__front,
.page-about .flip-card__back {
  position: absolute;
  inset: 0;
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  padding: 1.5rem 1.25rem;
  border-radius: var(--page-card-radius);
  backface-visibility: hidden;
  -webkit-backface-visibility: hidden;
  background: var(--color-card);
  border: 1px solid var(--color-border);
  text-align: center;
}
.page-about .flip-card__back {
  transform: rotateY(180deg);
  background: linear-gradient(135deg, var(--color-card) 0%, #1a334f 100%);
  border-color: var(--color-gold);
}
.page-about .flip-card__icon {
  display: block;
  width: 56px;
  height: 56px;
  object-fit: contain;
  margin-bottom: 0.75rem;
  opacity: 0.9;
}
.page-about .flip-card__label {
  font-size: 1.3rem;
  font-weight: 700;
  color: var(--color-gold);
  margin: 0 0 0.35rem;
  letter-spacing: 0.02em;
}
.page-about .flip-card__motto {
  font-size: 1rem;
  font-weight: 400;
  color: var(--color-text);
  line-height: 1.4;
  margin: 0;
  max-width: 220px;
}
.page-about .flip-card__detail {
  font-size: 0.95rem;
  line-height: 1.6;
  color: var(--color-text-secondary);
  margin: 0;
  max-width: 260px;
}

/* ---------- 我们的承诺 ---------- */
.page-about .commitment {
  position: relative;
  margin-bottom: 1rem;
  padding: 2rem 1.25rem;
  background: var(--color-card);
  border-radius: var(--page-card-radius);
  border: 1px solid var(--color-border);
  overflow: hidden;
}
.page-about .commitment__bg-texture {
  position: absolute;
  inset: 0;
  opacity: 0.06;
  pointer-events: none;
  z-index: 0;
}
.page-about .commitment__texture-img {
  display: block;
  width: 100%;
  height: 100%;
  object-fit: cover;
}
.page-about .commitment__heading {
  position: relative;
  z-index: 1;
  font-size: 1.8rem;
  font-weight: 700;
  color: var(--color-gold);
  letter-spacing: -0.01em;
  margin: 0 0 1.75rem;
  line-height: 1.2;
}
.page-about .commitment__list {
  position: relative;
  z-index: 1;
  display: flex;
  flex-direction: column;
  gap: 1.5rem;
  margin-bottom: 2rem;
}
.page-about .commitment__item {
  display: flex;
  gap: 1rem;
  align-items: flex-start;
}
.page-about .commitment__item-num {
  flex-shrink: 0;
  font-family: var(--font-mono);
  font-size: 1.6rem;
  font-weight: 700;
  color: var(--color-gold);
  opacity: 0.6;
  line-height: 1;
  margin-top: 0.1rem;
  width: 2.4rem;
}
.page-about .commitment__item-content {
  flex: 1;
}
.page-about .commitment__item-title {
  font-size: 1.1rem;
  font-weight: 600;
  color: var(--color-text);
  margin: 0 0 0.35rem;
  line-height: 1.3;
}
.page-about .commitment__item-desc {
  font-size: 0.95rem;
  line-height: 1.6;
  color: var(--color-text-secondary);
  margin: 0;
}
.page-about .commitment__note {
  position: relative;
  z-index: 1;
  margin: 1.5rem 0 1.75rem;
  padding: 1rem 1.25rem;
  background: var(--color-gold-dim);
  border-left: 3px solid var(--color-gold);
  border-radius: 0 8px 8px 0;
  font-size: 0.95rem;
  line-height: 1.6;
  color: var(--color-text-secondary);
  quotes: none;
}
.page-about .commitment__note p {
  margin: 0;
}
.page-about .commitment__cta-links {
  position: relative;
  z-index: 1;
  display: flex;
  flex-wrap: wrap;
  gap: 1rem;
}
.page-about .commitment__cta {
  display: inline-block;
  padding: 0.65rem 1.5rem;
  font-size: 0.95rem;
  font-weight: 500;
  color: var(--color-bg);
  background: var(--color-gold);
  border-radius: 6px;
  text-decoration: none;
  transition: background var(--transition), transform var(--transition);
  letter-spacing: 0.01em;
}
.page-about .commitment__cta:hover,
.page-about .commitment__cta:focus-visible {
  background: #c5a230;
  transform: translateY(-2px);
  outline: 2px solid var(--color-gold);
  outline-offset: 2px;
}
.page-about .commitment__cta--alt {
  background: transparent;
  color: var(--color-gold);
  border: 1px solid var(--color-gold);
}
.page-about .commitment__cta--alt:hover,
.page-about .commitment__cta--alt:focus-visible {
  background: var(--color-gold-dim);
  transform: translateY(-2px);
}

/* ========== 桌面端 ========== */
@media (min-width: 768px) {
  .page-about {
    padding: 2.5rem 2rem 4rem;
    --page-section-spacing: 5rem;
  }

  /* 首屏双栏 */
  .page-about .story-hero {
    flex-direction: row;
    align-items: center;
    gap: 3rem;
  }
  .page-about .story-hero__text {
    order: 1;
    flex: 1.1;
  }
  .page-about .story-hero__visual {
    order: 2;
    flex: 0.9;
  }
  .page-about .story-hero__heading {
    font-size: 2.8rem;
  }
  .page-about .story-hero__subtitle {
    font-size: 1.2rem;
  }

  /* 时间线水平排列 */
  .page-about .timeline__track {
    flex-direction: row;
    gap: 1.25rem;
    overflow-x: auto;
    padding-bottom: 0.5rem;
    scroll-snap-type: x mandatory;
    -webkit-overflow-scrolling: touch;
  }
  .page-about .timeline__node {
    flex: 0 0 260px;
    scroll-snap-align: start;
    min-height: 160px;
  }
  .page-about .timeline__node-title {
    padding: 1rem 1rem 0.75rem;
  }
  .page-about .timeline__node-title::after {
    display: none;
  }
  .page-about .timeline__node-desc {
    padding: 0 1rem 1rem;
  }

  /* 翻转卡片三列 */
  .page-about .ideals__grid {
    grid-template-columns: repeat(3, 1fr);
    gap: 1.75rem;
  }
  .page-about .flip-card {
    min-height: 280px;
  }
  .page-about .flip-card__inner {
    min-height: 280px;
  }
  .page-about .flip-card__front,
  .page-about .flip-card__back {
    padding: 2rem 1.5rem;
  }
  .page-about .flip-card__icon {
    width: 64px;
    height: 64px;
  }
  .page-about .flip-card__label {
    font-size: 1.4rem;
  }
  .page-about .flip-card__motto {
    font-size: 1.05rem;
  }

  /* 承诺部分双栏布局 */
  .page-about .commitment {
    padding: 2.5rem 2.5rem 2.5rem;
  }
  .page-about .commitment__list {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 1.75rem 2.5rem;
  }
  .page-about .commitment__item:nth-child(3) {
    grid-column: 1 / -1;
    max-width: 70%;
  }
  .page-about .commitment__item-num {
    font-size: 1.8rem;
    width: 2.8rem;
  }
  .page-about .commitment__note {
    max-width: 75%;
  }
  .page-about .commitment__cta-links {
    gap: 1.25rem;
  }
}

@media (min-width: 1024px) {
  .page-about .story-hero__heading {
    font-size: 3.2rem;
  }
  .page-about .timeline__node {
    flex-basis: 280px;
  }
  .page-about .commitment__list {
    grid-template-columns: repeat(3, 1fr);
  }
  .page-about .commitment__item:nth-child(3) {
    grid-column: auto;
    max-width: 100%;
  }
}