.page-about {
  --section-pad: 2.5rem 2rem;
  --radius-card: 8px;
  --glow-gold-soft: 0 0 20px rgba(212, 175, 55, 0.25);
  --glow-green-soft: 0 0 16px rgba(0, 255, 136, 0.2);
  display: flex;
  flex-direction: column;
  gap: 0;
  padding: 0;
  box-sizing: border-box;
  font-family: var(--font-body, 'Source Han Sans SC', 'Noto Sans SC', sans-serif);
  color: var(--color-text-light, #ffffff);
  background: var(--color-primary, #0A1F44);
  min-height: 100%;
}

/* ---------- 面包屑 ---------- */
.page-about .breadcrumb {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 0.4rem 0.6rem;
  padding: 1rem 2rem 0;
  font-size: 0.875rem;
  color: var(--color-text-muted, #B0B0B0);
  background: transparent;
}
.page-about .breadcrumb-item {
  color: var(--color-text-muted, #B0B0B0);
  text-decoration: none;
  transition: color var(--transition, 0.25s);
}
.page-about .breadcrumb-item:hover,
.page-about .breadcrumb-item:focus-visible {
  color: var(--color-accent, #D4AF37);
  outline: none;
  text-shadow: var(--glow-gold-soft);
}
.page-about .breadcrumb-current {
  color: var(--color-functional, #00FF88);
  font-weight: 600;
  pointer-events: none;
}
.page-about .breadcrumb-sep {
  color: var(--color-text-muted, #B0B0B0);
  user-select: none;
}

/* ---------- 通用章节 ---------- */
.page-about .section {
  width: 100%;
  box-sizing: border-box;
  padding: var(--section-pad);
}
.page-about .section-wide {
  background: var(--color-primary, #0A1F44);
}
.page-about .section-narrow {
  background: color-mix(in srgb, var(--color-primary, #0A1F44) 92%, #000);
  max-width: 100%;
}
.page-about .content-wrap {
  max-width: var(--content-max, 1200px);
  margin: 0 auto;
  display: flex;
  flex-direction: column;
  gap: 1.5rem;
}
.page-about .section-heading {
  font-family: var(--font-heading, 'Exo 2', 'Arial Black', sans-serif);
  font-size: 1.75rem;
  font-weight: 700;
  color: var(--color-accent, #D4AF37);
  margin: 0 0 0.5rem;
  letter-spacing: 0.02em;
  line-height: 1.2;
}

/* ---------- 品牌介绍（宽幅） ---------- */
.page-about .brand-intro {
  padding-top: 2rem;
  position: relative;
}
.page-about .brand-intro .content-wrap {
  flex-direction: row;
  flex-wrap: wrap;
  align-items: center;
  justify-content: space-between;
  gap: 2rem;
}
.page-about .intro-text {
  flex: 1 1 55%;
  min-width: 280px;
  display: flex;
  flex-direction: column;
  gap: 0.75rem;
}
.page-about .intro-heading {
  font-family: var(--font-heading, 'Exo 2', 'Arial Black', sans-serif);
  font-size: 2.5rem;
  font-weight: 700;
  color: var(--color-accent, #D4AF37);
  margin: 0;
  line-height: 1.1;
  text-shadow: var(--glow-gold-soft);
  letter-spacing: 0.03em;
}
.page-about .intro-sub {
  font-size: 1.125rem;
  font-weight: 500;
  color: var(--color-functional, #00FF88);
  margin: 0;
  letter-spacing: 0.02em;
}
.page-about .intro-desc {
  font-size: 1rem;
  line-height: 1.7;
  color: var(--color-text-light, #ffffff);
  margin: 0;
  max-width: 42em;
  opacity: 0.9;
}
.page-about .intro-stats {
  display: flex;
  flex-wrap: wrap;
  gap: 1.5rem 2.5rem;
  margin-top: 0.5rem;
  padding-top: 1rem;
  border-top: 1px solid rgba(212, 175, 55, 0.25);
}
.page-about .stat-item {
  display: flex;
  flex-direction: column;
  gap: 0.15rem;
}
.page-about .stat-num {
  font-family: var(--font-heading, 'Exo 2', 'Arial Black', sans-serif);
  font-size: 1.5rem;
  font-weight: 700;
  color: var(--color-accent, #D4AF37);
  line-height: 1;
}
.page-about .stat-label {
  font-size: 0.8rem;
  color: var(--color-text-muted, #B0B0B0);
  text-transform: uppercase;
  letter-spacing: 0.06em;
}
.page-about .intro-visual {
  flex: 0 0 auto;
  display: flex;
  align-items: center;
  justify-content: center;
}
.page-about .intro-icon {
  display: block;
  width: 200px;
  max-width: 100%;
  height: auto;
  aspect-ratio: 1/1;
  object-fit: contain;
  border-radius: var(--radius-card, 8px);
  filter: drop-shadow(0 0 24px rgba(212, 175, 55, 0.3));
}

/* ---------- 服务理念（窄幅） ---------- */
.page-about .philosophy {
  padding: 2.5rem 2rem;
  border-top: 2px solid rgba(212, 175, 55, 0.12);
  border-bottom: 2px solid rgba(212, 175, 55, 0.12);
}
.page-about .philosophy .content-wrap {
  flex-direction: row;
  flex-wrap: wrap;
  align-items: flex-start;
  gap: 2rem;
}
.page-about .philosophy-visual {
  flex: 0 0 40%;
  min-width: 240px;
  display: flex;
  align-items: center;
  justify-content: center;
}
.page-about .philosophy-img {
  display: block;
  width: 100%;
  max-width: 400px;
  height: auto;
  aspect-ratio: 3/2;
  object-fit: cover;
  border-radius: var(--radius-card, 8px);
  box-shadow: var(--shadow-card, 0 4px 20px rgba(0,0,0,0.06));
}
.page-about .philosophy-text {
  flex: 1 1 50%;
  min-width: 260px;
  display: flex;
  flex-direction: column;
  gap: 0.75rem;
}
.page-about .philosophy-desc {
  font-size: 1rem;
  line-height: 1.6;
  color: var(--color-text-light, #ffffff);
  margin: 0 0 0.5rem;
  opacity: 0.85;
}
.page-about .value-list {
  list-style: none;
  margin: 0;
  padding: 0;
  display: flex;
  flex-direction: column;
  gap: 1rem;
}
.page-about .value-item {
  display: flex;
  gap: 0.75rem;
  align-items: flex-start;
  padding: 0.75rem 1rem;
  background: rgba(255, 255, 255, 0.06);
  border-radius: var(--radius-card, 8px);
  border-left: 3px solid var(--color-accent, #D4AF37);
  transition: background var(--transition, 0.25s), box-shadow var(--transition, 0.25s);
}
.page-about .value-item:hover {
  background: rgba(255, 255, 255, 0.1);
  box-shadow: var(--glow-gold-soft);
}
.page-about .value-icon {
  flex: 0 0 2rem;
  font-family: var(--font-heading, 'Exo 2', 'Arial Black', sans-serif);
  font-size: 1.25rem;
  font-weight: 700;
  color: var(--color-functional, #00FF88);
  line-height: 1.4;
  opacity: 0.8;
}
.page-about .value-title {
  display: block;
  font-family: var(--font-heading, 'Exo 2', 'Arial Black', sans-serif);
  font-size: 1.05rem;
  font-weight: 600;
  color: var(--color-accent, #D4AF37);
  margin-bottom: 0.2rem;
}
.page-about .value-desc {
  display: block;
  font-size: 0.9rem;
  line-height: 1.5;
  color: var(--color-text-light, #ffffff);
  opacity: 0.75;
}
.page-about .philosophy-cta {
  align-self: flex-start;
  margin-top: 0.5rem;
  background: var(--color-functional, #00FF88);
  color: var(--color-primary, #0A1F44);
  font-family: var(--font-heading, 'Exo 2', 'Arial Black', sans-serif);
  font-weight: 600;
  font-size: 0.95rem;
  padding: 0.7rem 1.8rem;
  border-radius: var(--radius-card, 8px);
  text-decoration: none;
  transition: box-shadow var(--transition, 0.25s), transform var(--transition, 0.25s);
  cursor: pointer;
  display: inline-block;
  border: none;
}
.page-about .philosophy-cta:hover,
.page-about .philosophy-cta:focus-visible {
  box-shadow: var(--glow-green-soft);
  transform: translateY(-1px);
  outline: none;
}

/* ---------- 差异化亮点（宽幅） ---------- */
.page-about .diff {
  padding-top: 2.5rem;
  padding-bottom: 3rem;
}
.page-about .diff-heading {
  text-align: center;
  margin-bottom: 0.25rem;
}
.page-about .diff-desc {
  text-align: center;
  font-size: 1rem;
  color: var(--color-text-muted, #B0B0B0);
  margin: 0 0 1.5rem;
  max-width: 36em;
  margin-left: auto;
  margin-right: auto;
}
.page-about .skill-tree {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  justify-content: center;
  gap: 0.25rem 0.5rem;
  margin: 1rem 0 2rem;
  padding: 1.5rem 1rem;
  background: rgba(255, 255, 255, 0.04);
  border-radius: var(--radius-card, 8px);
  border: 1px solid rgba(212, 175, 55, 0.15);
}
.page-about .tree-node {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 0.35rem;
  padding: 1rem 1.25rem;
  min-width: 100px;
  text-align: center;
  background: rgba(255, 255, 255, 0.07);
  border-radius: var(--radius-card, 8px);
  border: 1px solid rgba(212, 175, 55, 0.2);
  cursor: default;
  transition: transform var(--transition, 0.25s), box-shadow var(--transition, 0.25s), border-color var(--transition, 0.25s);
  outline: none;
}
.page-about .tree-node:hover,
.page-about .tree-node:focus-visible {
  transform: scale(1.06);
  box-shadow: var(--glow-gold-soft);
  border-color: var(--color-accent, #D4AF37);
  background: rgba(212, 175, 55, 0.12);
}
.page-about .tree-node:focus-visible {
  outline: 2px solid var(--color-functional, #00FF88);
  outline-offset: 3px;
}
.page-about .node-icon {
  font-size: 1.75rem;
  line-height: 1;
}
.page-about .node-label {
  font-family: var(--font-heading, 'Exo 2', 'Arial Black', sans-serif);
  font-size: 0.9rem;
  font-weight: 600;
  color: var(--color-text-light, #ffffff);
  line-height: 1.3;
}
.page-about .node-label small {
  display: block;
  font-family: var(--font-body, 'Source Han Sans SC', sans-serif);
  font-size: 0.7rem;
  font-weight: 400;
  color: var(--color-text-muted, #B0B0B0);
  margin-top: 0.15rem;
}
.page-about .tree-connector {
  flex: 0 0 auto;
  display: flex;
  align-items: center;
  justify-content: center;
  width: 80px;
  max-width: 12vw;
}
.page-about .tree-connector svg {
  display: block;
  width: 100%;
  height: auto;
}
.page-about .diff-visual {
  display: flex;
  justify-content: center;
  margin: 1rem 0 1.5rem;
}
.page-about .diff-img {
  display: block;
  width: 100%;
  max-width: 720px;
  height: auto;
  aspect-ratio: 4/3;
  object-fit: contain;
  border-radius: var(--radius-card, 8px);
  box-shadow: 0 0 30px rgba(212, 175, 55, 0.1);
  background: rgba(255, 255, 255, 0.03);
}
.page-about .diff-links {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  justify-content: center;
  gap: 0.5rem 1.2rem;
  font-size: 0.9rem;
  color: var(--color-text-muted, #B0B0B0);
  margin-top: 0.5rem;
  padding-top: 1rem;
  border-top: 1px solid rgba(212, 175, 55, 0.12);
}
.page-about .diff-link {
  color: var(--color-functional, #00FF88);
  text-decoration: none;
  font-weight: 500;
  transition: color var(--transition, 0.25s), text-shadow var(--transition, 0.25s);
}
.page-about .diff-link:hover,
.page-about .diff-link:focus-visible {
  color: var(--color-accent, #D4AF37);
  text-shadow: var(--glow-gold-soft);
  outline: none;
}

/* ========== 响应式 ========== */
@media (min-width: 768px) {
  .page-about {
    --section-pad: 3rem 3rem;
  }
  .page-about .breadcrumb {
    padding: 1.5rem 3rem 0;
  }
  .page-about .intro-heading {
    font-size: 3.2rem;
  }
  .page-about .intro-icon {
    width: 300px;
  }
  .page-about .philosophy {
    padding: 3rem 3rem;
  }
  .page-about .skill-tree {
    flex-wrap: nowrap;
    gap: 0.5rem 1rem;
  }
  .page-about .tree-connector {
    width: 100px;
  }
}

@media (min-width: 1024px) {
  .page-about {
    --section-pad: 3.5rem 3.5rem;
  }
  .page-about .breadcrumb {
    padding: 1.5rem 3.5rem 0;
  }
  .page-about .intro-heading {
    font-size: 3.8rem;
  }
  .page-about .intro-icon {
    width: 340px;
  }
  .page-about .philosophy {
    padding: 3.5rem 3.5rem;
  }
  .page-about .section-narrow .content-wrap {
    max-width: 960px;
  }
  .page-about .tree-node {
    min-width: 130px;
    padding: 1.25rem 1.5rem;
  }
  .page-about .tree-connector {
    width: 120px;
  }
  .page-about .diff-img {
    max-width: 800px;
  }
}

@media (max-width: 600px) {
  .page-about .breadcrumb {
    padding: 0.75rem 1rem 0;
    font-size: 0.8rem;
  }
  .page-about .section {
    padding: 1.5rem 1rem;
  }
  .page-about .intro-heading {
    font-size: 1.8rem;
  }
  .page-about .intro-sub {
    font-size: 1rem;
  }
  .page-about .intro-stats {
    gap: 0.8rem 1.5rem;
  }
  .page-about .intro-visual {
    width: 100%;
  }
  .page-about .intro-icon {
    width: 160px;
  }
  .page-about .philosophy {
    padding: 1.5rem 1rem;
  }
  .page-about .philosophy-visual {
    flex-basis: 100%;
  }
  .page-about .philosophy-img {
    max-width: 100%;
  }
  .page-about .value-item {
    padding: 0.6rem 0.75rem;
  }
  .page-about .skill-tree {
    flex-direction: column;
    gap: 0.5rem;
    padding: 1rem 0.75rem;
  }
  .page-about .tree-connector {
    width: 100%;
    max-width: 100%;
    transform: rotate(90deg);
    margin: 0.25rem 0;
  }
  .page-about .tree-connector svg {
    width: 48px;
  }
  .page-about .diff-links {
    flex-direction: column;
    align-items: center;
    gap: 0.4rem;
  }
}

@media (prefers-reduced-motion: reduce) {
  .page-about *,
  .page-about *::before,
  .page-about *::after {
    transition-duration: 0.01ms !important;
    animation-duration: 0.01ms !important;
  }
  .page-about .tree-node:hover,
  .page-about .tree-node:focus-visible {
    transform: none;
  }
}