.page-about {
  --about-cream: #FFF8E7;
  --about-brown: #3C2415;
  --about-red: #FF4500;
  --about-green: #2E8B57;
  --about-gold: #FFD700;
  --about-silver: #C0C0C0;
  --about-charcoal: #1A1A1A;
  --about-off-white: #FFF5E0;
  --about-font-heading: Impact, 'Arial Black', sans-serif;
  --about-font-body: Georgia, 'Times New Roman', serif;
  --about-font-ui: 'Segoe UI', 'Helvetica Neue', sans-serif;
  --about-side-index-width: 180px;
  --about-content-max: 840px;

  display: block;
  width: 100%;
  max-width: 100%;
  background-color: var(--about-cream);
  color: var(--about-brown);
  font-family: var(--about-font-body);
  line-height: 1.6;
  padding: 0;
  margin: 0;
}

/* ---------- 面包屑 ---------- */
.page-about .breadcrumb {
  display: flex;
  align-items: center;
  gap: 0.4rem;
  padding: 1rem 1.2rem 0.4rem;
  font-family: var(--about-font-ui);
  font-size: 0.85rem;
  color: var(--about-brown);
  opacity: 0.7;
  max-width: var(--about-content-max);
  margin-left: auto;
  margin-right: auto;
}
.page-about .breadcrumb a {
  color: var(--about-brown);
  text-decoration: none;
  transition: color 0.2s ease;
}
.page-about .breadcrumb a:hover,
.page-about .breadcrumb a:focus {
  color: var(--about-red);
  text-decoration: underline;
}
.page-about .breadcrumb-sep {
  margin: 0 0.1rem;
  color: var(--about-silver);
}
.page-about .breadcrumb [aria-current="page"] {
  font-weight: 600;
  color: var(--about-red);
}

/* ---------- HERO 分屏首屏 ---------- */
.page-about .about-hero {
  display: flex;
  flex-direction: column;
  gap: 1.5rem;
  padding: 1.5rem 1.2rem 2rem;
  max-width: var(--about-content-max);
  margin-left: auto;
  margin-right: auto;
}
.page-about .hero-text {
  flex: 1 1 50%;
}
.page-about .hero-text h1 {
  font-family: var(--about-font-heading);
  font-size: 2.6rem;
  line-height: 1.1;
  color: var(--about-brown);
  margin: 0 0 0.75rem;
  text-transform: uppercase;
  letter-spacing: -0.02em;
}
.page-about .hero-tagline {
  font-family: var(--about-font-heading);
  font-size: 1.2rem;
  color: var(--about-red);
  margin: 0 0 0.8rem;
  letter-spacing: 0.04em;
}
.page-about .hero-desc {
  font-size: 1rem;
  color: var(--about-brown);
  opacity: 0.88;
  max-width: 38em;
  margin: 0;
}
.page-about .hero-visual {
  flex: 0 0 auto;
  display: flex;
  justify-content: center;
  align-items: center;
}
.page-about .hero-img {
  max-width: 100%;
  height: auto;
  width: 100%;
  max-width: 400px;
  object-fit: contain;
  border-radius: 12px;
  box-shadow: var(--shadow-soft, 0 4px 20px rgba(0,0,0,0.08));
}

/* ---------- 内容布局（索引 + 主体） ---------- */
.page-about .about-layout {
  display: flex;
  flex-direction: column;
  gap: 1.5rem;
  padding: 0 1.2rem 3rem;
  max-width: var(--about-content-max);
  margin-left: auto;
  margin-right: auto;
}

/* ---------- 章节索引（移动端在顶部） ---------- */
.page-about .about-index {
  background: var(--about-off-white);
  border-left: 6px solid var(--about-red);
  padding: 1rem 1.2rem;
  border-radius: 0 8px 8px 0;
  flex-shrink: 0;
}
.page-about .index-heading {
  font-family: var(--about-font-heading);
  font-size: 1rem;
  color: var(--about-brown);
  margin: 0 0 0.6rem;
  text-transform: uppercase;
  letter-spacing: 0.06em;
}
.page-about .index-list {
  list-style: none;
  margin: 0;
  padding: 0;
  display: flex;
  flex-wrap: wrap;
  gap: 0.6rem 1.2rem;
}
.page-about .index-link {
  font-family: var(--about-font-ui);
  font-size: 0.9rem;
  color: var(--about-brown);
  text-decoration: none;
  padding: 0.2rem 0;
  border-bottom: 2px solid transparent;
  transition: border-color 0.25s ease, color 0.25s ease;
  white-space: nowrap;
}
.page-about .index-link:hover,
.page-about .index-link:focus {
  border-bottom-color: var(--about-red);
  color: var(--about-red);
}

/* ---------- 主体内容 ---------- */
.page-about .about-main {
  flex: 1 1 100%;
  min-width: 0;
}

/* ---------- 通用章节 ---------- */
.page-about .about-section {
  margin-bottom: 3.2rem;
  scroll-margin-top: 2rem;
}
.page-about .section-title {
  font-family: var(--about-font-heading);
  font-size: 1.8rem;
  line-height: 1.2;
  color: var(--about-brown);
  margin: 0 0 0.6rem;
  display: flex;
  align-items: baseline;
  gap: 0.5rem;
  text-transform: uppercase;
}
.page-about .title-num {
  font-size: 1.2rem;
  color: var(--about-red);
  font-family: var(--about-font-ui);
  font-weight: 700;
  letter-spacing: 0.02em;
}
.page-about .section-intro {
  font-size: 1rem;
  color: var(--about-brown);
  opacity: 0.8;
  margin: 0 0 1.5rem;
  max-width: 40em;
}

/* ---------- 品牌原则卡片 ---------- */
.page-about .principles-grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: 1.2rem;
}
.page-about .principle-card {
  background: var(--about-off-white);
  padding: 1.5rem 1.2rem;
  border-radius: 10px;
  border-left: 6px solid var(--about-red);
  box-shadow: var(--shadow-soft, 0 4px 20px rgba(0,0,0,0.06));
  transition: transform 0.25s ease, box-shadow 0.25s ease;
}
.page-about .principle-card:hover {
  transform: translateY(-3px);
  box-shadow: var(--shadow-strong, 0 8px 40px rgba(0,0,0,0.12));
}
.page-about .principle-icon {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 2.4rem;
  height: 2.4rem;
  background: var(--about-red);
  color: #fff;
  font-family: var(--about-font-heading);
  font-size: 1.4rem;
  border-radius: 50%;
  margin-bottom: 0.6rem;
}
.page-about .principle-name {
  font-family: var(--about-font-heading);
  font-size: 1.3rem;
  color: var(--about-brown);
  margin: 0 0 0.4rem;
  text-transform: uppercase;
  letter-spacing: 0.02em;
}
.page-about .principle-desc {
  font-size: 0.95rem;
  color: var(--about-brown);
  opacity: 0.85;
  margin: 0 0 0.8rem;
  line-height: 1.6;
}
.page-about .principle-link {
  font-family: var(--about-font-ui);
  font-size: 0.9rem;
  color: var(--about-red);
  text-decoration: none;
  font-weight: 600;
  transition: gap 0.2s ease;
  display: inline-flex;
  align-items: center;
  gap: 0.3rem;
}
.page-about .principle-link:hover,
.page-about .principle-link:focus {
  text-decoration: underline;
  gap: 0.6rem;
}
.page-about .link-arrow {
  transition: transform 0.2s ease;
}
.page-about .principle-link:hover .link-arrow,
.page-about .principle-link:focus .link-arrow {
  transform: translateX(4px);
}

/* ---------- 故事脉络时间线 ---------- */
.page-about .timeline {
  position: relative;
  padding-left: 2rem;
  margin-bottom: 2rem;
}
.page-about .timeline::before {
  content: '';
  position: absolute;
  left: 0.6rem;
  top: 0.4rem;
  bottom: 0.4rem;
  width: 4px;
  background: var(--about-silver);
  border-radius: 2px;
}
.page-about .timeline-item {
  position: relative;
  padding-bottom: 1.4rem;
}
.page-about .timeline-item:last-child {
  padding-bottom: 0;
}
.page-about .timeline-node {
  position: absolute;
  left: -2rem;
  top: 0.3rem;
  width: 16px;
  height: 16px;
  border-radius: 50%;
  background: var(--about-red);
  border: 4px solid var(--about-cream);
  box-shadow: 0 0 0 2px var(--about-red);
  z-index: 1;
}
.page-about .timeline-content {
  padding-left: 0.4rem;
}
.page-about .timeline-details {
  display: block;
  cursor: pointer;
}
.page-about .timeline-summary {
  font-family: var(--about-font-heading);
  font-size: 1.1rem;
  color: var(--about-brown);
  padding: 0.4rem 0.6rem;
  border-radius: 6px;
  transition: background 0.2s ease, color 0.2s ease;
  list-style: none;
  display: inline-block;
}
.page-about .timeline-summary::-webkit-details-marker {
  display: none;
}
.page-about .timeline-summary::before {
  content: '▶ ';
  font-size: 0.75rem;
  color: var(--about-red);
  transition: transform 0.25s ease;
  display: inline-block;
  margin-right: 0.3rem;
}
.page-about .timeline-details[open] .timeline-summary::before {
  transform: rotate(90deg);
}
.page-about .timeline-summary:hover,
.page-about .timeline-details[open] .timeline-summary {
  background: var(--about-off-white);
  color: var(--about-red);
}
.page-about .timeline-body {
  padding: 0.6rem 0.6rem 0.2rem 1.6rem;
  font-size: 0.95rem;
  color: var(--about-brown);
  opacity: 0.88;
  line-height: 1.6;
}
.page-about .timeline-body p {
  margin: 0 0 0.4rem;
}
.page-about .timeline-visual {
  display: flex;
  justify-content: center;
  margin-top: 1.5rem;
}
.page-about .timeline-img {
  max-width: 100%;
  height: auto;
  width: 100%;
  max-width: 240px;
  border-radius: 10px;
  box-shadow: var(--shadow-soft, 0 4px 20px rgba(0,0,0,0.06));
  object-fit: contain;
}

/* ---------- 团队价值观 ---------- */
.page-about .values-grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: 1.2rem;
  margin-bottom: 1.5rem;
}
.page-about .value-card {
  background: var(--about-off-white);
  padding: 1.4rem 1.2rem;
  border-radius: 10px;
  border-top: 6px solid transparent;
  box-shadow: var(--shadow-soft, 0 4px 20px rgba(0,0,0,0.06));
  transition: transform 0.25s ease, box-shadow 0.25s ease;
}
.page-about .value-card:hover {
  transform: translateY(-3px);
  box-shadow: var(--shadow-strong, 0 8px 40px rgba(0,0,0,0.12));
}
.page-about .value-visual {
  margin-bottom: 0.6rem;
}
.page-about .value-shape {
  display: inline-block;
  width: 2.8rem;
  height: 2.8rem;
  border-radius: 8px;
  opacity: 0.85;
}
.page-about .value-name {
  font-family: var(--about-font-heading);
  font-size: 1.2rem;
  color: var(--about-brown);
  margin: 0 0 0.4rem;
  text-transform: uppercase;
  letter-spacing: 0.02em;
}
.page-about .value-desc {
  font-size: 0.95rem;
  color: var(--about-brown);
  opacity: 0.85;
  margin: 0;
  line-height: 1.6;
}
.page-about .values-image-block {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 1rem;
  margin-top: 0.5rem;
}
.page-about .values-img {
  max-width: 100%;
  height: auto;
  width: 100%;
  max-width: 240px;
  border-radius: 10px;
  box-shadow: var(--shadow-soft, 0 4px 20px rgba(0,0,0,0.06));
  object-fit: contain;
}
.page-about .values-cta {
  font-size: 1rem;
  color: var(--about-brown);
  text-align: center;
  margin: 0;
}
.page-about .inline-link {
  color: var(--about-red);
  text-decoration: none;
  font-weight: 600;
  border-bottom: 2px solid transparent;
  transition: border-color 0.2s ease, color 0.2s ease;
}
.page-about .inline-link:hover,
.page-about .inline-link:focus {
  border-bottom-color: var(--about-red);
  color: var(--about-charcoal);
}

/* ========== 桌面端 (min-width: 768px) ========== */
@media (min-width: 768px) {
  .page-about .breadcrumb {
    padding: 1.2rem 0 0.6rem;
  }

  .page-about .about-hero {
    flex-direction: row;
    align-items: center;
    gap: 2.5rem;
    padding: 2rem 0 2.5rem;
  }
  .page-about .hero-text h1 {
    font-size: 3.2rem;
  }
  .page-about .hero-tagline {
    font-size: 1.4rem;
  }
  .page-about .hero-desc {
    font-size: 1.05rem;
  }
  .page-about .hero-img {
    max-width: 480px;
  }

  .page-about .about-layout {
    flex-direction: row;
    gap: 2.5rem;
    padding: 0 0 4rem;
  }

  .page-about .about-index {
    width: var(--about-side-index-width);
    flex-shrink: 0;
    position: sticky;
    top: 2rem;
    align-self: flex-start;
    padding: 1.2rem 1.4rem;
    border-left-width: 8px;
  }
  .page-about .index-heading {
    font-size: 1.1rem;
    margin-bottom: 0.8rem;
  }
  .page-about .index-list {
    flex-direction: column;
    gap: 0.4rem;
  }
  .page-about .index-link {
    font-size: 0.95rem;
    padding: 0.3rem 0;
    border-bottom: none;
    border-left: 3px solid transparent;
    padding-left: 0.6rem;
    white-space: normal;
  }
  .page-about .index-link:hover,
  .page-about .index-link:focus {
    border-left-color: var(--about-red);
    border-bottom-color: transparent;
  }

  .page-about .section-title {
    font-size: 2.2rem;
  }
  .page-about .title-num {
    font-size: 1.4rem;
  }

  .page-about .principles-grid {
    grid-template-columns: repeat(3, 1fr);
    gap: 1.5rem;
  }
  .page-about .principle-card {
    padding: 1.8rem 1.4rem;
  }
  .page-about .principle-icon {
    width: 2.8rem;
    height: 2.8rem;
    font-size: 1.6rem;
  }
  .page-about .principle-name {
    font-size: 1.4rem;
  }

  .page-about .timeline {
    padding-left: 2.4rem;
  }
  .page-about .timeline-summary {
    font-size: 1.15rem;
    padding: 0.5rem 0.8rem;
  }
  .page-about .timeline-body {
    padding-left: 2rem;
  }
  .page-about .timeline-img {
    max-width: 280px;
  }

  .page-about .values-grid {
    grid-template-columns: repeat(3, 1fr);
    gap: 1.5rem;
  }
  .page-about .value-card {
    padding: 1.6rem 1.4rem;
  }
  .page-about .value-name {
    font-size: 1.3rem;
  }
  .page-about .values-img {
    max-width: 280px;
  }
}

/* ========== 大桌面端 (min-width: 1024px) ========== */
@media (min-width: 1024px) {
  .page-about .hero-text h1 {
    font-size: 3.6rem;
  }
  .page-about .hero-tagline {
    font-size: 1.6rem;
  }
  .page-about .hero-img {
    max-width: 500px;
  }
  .page-about .section-title {
    font-size: 2.4rem;
  }
  .page-about .principles-grid {
    gap: 2rem;
  }
  .page-about .values-grid {
    gap: 2rem;
  }
  .page-about .timeline-img,
  .page-about .values-img {
    max-width: 300px;
  }
}