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

/* ===== 首屏 Hero ===== */
.page-about__hero {
  position: relative;
  overflow: hidden;
  background: var(--color-primary);
  color: var(--color-white);
  padding: 3rem 0 2.75rem;
}

.page-about__hero::before {
  content: "";
  position: absolute;
  top: -30px;
  right: -30px;
  width: 160px;
  height: 160px;
  border: 2px solid rgba(212, 175, 55, 0.45);
  transform: rotate(15deg);
  pointer-events: none;
}

.page-about__hero::after {
  content: "";
  position: absolute;
  left: -40px;
  bottom: -40px;
  width: 120px;
  height: 120px;
  border: 1px solid rgba(0, 168, 168, 0.5);
  transform: rotate(45deg);
  pointer-events: none;
}

.page-about__hero-inner {
  position: relative;
  z-index: 1;
  display: grid;
  gap: 2rem;
}

.page-about__hero-copy h1 {
  font-family: var(--font-head);
  font-size: var(--font-h1);
  font-weight: 700;
  line-height: 1.22;
  margin: 0.9rem 0 1rem;
  max-width: 12em;
}

.page-about__eyebrow {
  display: inline-block;
  padding: 0.3rem 0.7rem;
  border: 1px solid rgba(212, 175, 55, 0.55);
  color: var(--color-gold);
  font-size: 0.8rem;
  font-weight: 600;
  letter-spacing: 0.14em;
  text-transform: uppercase;
}

.page-about__lead {
  max-width: 30em;
  margin: 0;
  font-size: 1rem;
  line-height: 1.75;
  color: rgba(255, 255, 255, 0.85);
}

.page-about__chapter-nav {
  display: flex;
  flex-direction: column;
  gap: 0.25rem;
  padding: 1.25rem 1.25rem 0.75rem;
  background: rgba(255, 255, 255, 0.05);
  border: 2px solid rgba(212, 175, 55, 0.6);
}

.page-about__chapter-title {
  margin: 0 0 0.5rem;
  font-size: 0.8rem;
  font-weight: 700;
  letter-spacing: 0.12em;
  text-transform: uppercase;
  color: var(--color-gold-light);
}

.page-about__chapter-nav a {
  display: flex;
  align-items: center;
  gap: 0.8rem;
  padding: 0.55rem 0.25rem;
  border-bottom: 1px solid rgba(255, 255, 255, 0.14);
  color: var(--color-white);
  font-size: 0.95rem;
  text-decoration: none;
  transition: background-color 0.25s ease, padding-left 0.25s ease;
}

.page-about__chapter-nav a:last-child {
  border-bottom: 0;
}

.page-about__chapter-nav a:hover,
.page-about__chapter-nav a:focus-visible {
  padding-left: 0.6rem;
  background: rgba(212, 175, 55, 0.16);
  outline: none;
}

.page-about__chapter-index {
  font-family: var(--font-head);
  font-size: 0.85rem;
  font-weight: 700;
  color: var(--color-gold);
}

.page-about__hero-stats {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 0.75rem;
}

.page-about__stat {
  padding: 0.9rem 1rem;
  border: 1px solid rgba(255, 255, 255, 0.25);
  background: rgba(255, 255, 255, 0.06);
}

.page-about__stat-num {
  display: block;
  font-family: var(--font-head);
  font-size: 2rem;
  font-weight: 700;
  line-height: 1.1;
  color: var(--color-gold);
}

.page-about__stat-label {
  display: block;
  margin-top: 0.2rem;
  font-size: 0.8rem;
  color: rgba(255, 255, 255, 0.8);
}

/* ===== 面包屑 ===== */
.page-about__crumb {
  padding: 0.7rem 0;
  background: var(--color-bg);
  border-bottom: 2px solid var(--color-gold);
}

/* ===== 通用章节头 ===== */
.page-about__head {
  max-width: 46rem;
  margin-bottom: 2rem;
}

.page-about__head-note {
  margin-top: 0.8rem;
  line-height: 1.65;
  color: var(--color-text-secondary);
}

/* ===== 发展历程 ===== */
.page-about__journey {
  background: var(--color-bg);
  padding: var(--space-xxl) 0;
}

.page-about__timeline-scroll {
  overflow-x: auto;
  padding-bottom: 1rem;
  scroll-snap-type: x mandatory;
  -webkit-overflow-scrolling: touch;
  overscroll-behavior-x: contain;
}

.page-about__timeline-scroll:focus-visible {
  outline: 2px solid var(--color-teal);
  outline-offset: 4px;
}

.page-about__timeline {
  display: flex;
  gap: 1rem;
  min-width: max-content;
  margin: 0;
  padding: 0 0 0.25rem;
  list-style: none;
}

.page-about__milestone {
  position: relative;
  flex: 0 0 auto;
  width: 78vw;
  min-width: 260px;
  max-width: 78vw;
  padding: 1.5rem 1.25rem;
  background: var(--color-white);
  border: 2px solid var(--color-primary);
  box-shadow: var(--shadow-hard);
  scroll-snap-align: start;
  transition: transform 0.25s ease, box-shadow 0.25s ease;
}

.page-about__milestone::before {
  content: "";
  display: block;
  height: 4px;
  margin-bottom: 1rem;
  background: linear-gradient(90deg, var(--color-gold) 0%, var(--color-gold) 60%, rgba(212, 175, 55, 0.25) 100%);
}

.page-about__milestone:hover,
.page-about__milestone:focus-within {
  transform: translateY(-4px);
  box-shadow: 8px 8px 0 rgba(10, 31, 68, 0.85);
}

.page-about__milestone-phase {
  display: inline-block;
  margin: 0 0 0.6rem;
  padding: 0.25rem 0.6rem;
  background: var(--color-primary);
  color: var(--color-gold);
  font-size: 0.75rem;
  font-weight: 600;
  letter-spacing: 0.08em;
}

.page-about__milestone h3 {
  margin: 0 0 0.5rem;
  font-family: var(--font-head);
  font-size: 1.15rem;
}

.page-about__milestone p:last-child {
  margin: 0;
  font-size: 0.9rem;
  line-height: 1.6;
  color: var(--color-text-secondary);
}

.page-about__journey-figures {
  display: grid;
  gap: 1.25rem;
  margin-top: 2.25rem;
}

.page-about__figure {
  margin: 0;
  padding: 0.5rem;
  background: var(--color-white);
  border: 2px solid var(--color-primary);
  box-shadow: var(--shadow-hard);
}

.page-about__figure img {
  display: block;
  width: 100%;
  height: auto;
}

.page-about__figure figcaption {
  padding: 0.65rem 0.1rem 0.15rem;
  font-size: var(--font-small);
  color: var(--color-text-secondary);
}

/* ===== 服务理念 ===== */
.page-about__philosophy {
  background: var(--color-white);
  padding: var(--space-xxl) 0;
}

.page-about__philosophy-head {
  display: grid;
  gap: 1.5rem;
  align-items: center;
  margin-bottom: 2.5rem;
}

.page-about__philosophy-copy .section-title {
  margin: 0.6rem 0 1rem;
}

.page-about__philosophy-copy p:last-child {
  max-width: 28em;
  line-height: 1.7;
  color: var(--color-text-secondary);
}

.page-about__philosophy-figure {
  margin: 0;
  padding: 0.6rem;
  background: var(--color-bg);
  border: 2px solid var(--color-primary);
  box-shadow: var(--shadow-gold);
}

.page-about__philosophy-figure img {
  display: block;
  width: 100%;
  height: auto;
}

.page-about__principles {
  display: grid;
  gap: 1rem;
}

.page-about__principle {
  position: relative;
  padding: 1.25rem 1.25rem 1.25rem 1.5rem;
  background: var(--color-bg);
  border: 2px solid var(--color-primary);
}

.page-about__principle-num {
  position: absolute;
  top: 0.9rem;
  right: 1rem;
  font-family: var(--font-head);
  font-size: 1.4rem;
  font-weight: 700;
  color: var(--color-gold);
  opacity: 0.4;
}

.page-about__principle h3 {
  margin: 0 0 0.45rem;
  padding-right: 2.5rem;
  font-family: var(--font-head);
  font-size: 1.1rem;
}

.page-about__principle p {
  margin: 0;
  font-size: 0.9rem;
  line-height: 1.65;
  color: var(--color-text-secondary);
}

/* ===== 资质与认证 ===== */
.page-about__certifications {
  background: var(--color-primary);
  color: var(--color-white);
  padding: var(--space-xxl) 0;
}

.page-about__cert-head {
  max-width: 42rem;
  margin-bottom: 2rem;
}

.page-about__cert-head .section-title {
  margin: 0.6rem 0 1rem;
  color: var(--color-white);
}

.page-about__cert-head p {
  margin: 0;
  line-height: 1.65;
  color: rgba(255, 255, 255, 0.85);
}

.page-about__cert-layout {
  display: grid;
  gap: 1.25rem;
}

.page-about__cert-card {
  padding: 1.5rem;
  background: var(--color-white);
  color: var(--color-text);
  border: 2px solid var(--color-gold);
  box-shadow: var(--shadow-gold);
}

.page-about__cert-card h3 {
  margin: 0.5rem 0;
  font-family: var(--font-head);
  font-size: 1.2rem;
}

.page-about__cert-card p {
  margin: 0;
  font-size: 0.9rem;
  line-height: 1.65;
  color: var(--color-text-secondary);
}

.page-about__cert-list {
  display: grid;
  gap: 0.4rem;
  margin: 1rem 0 0;
  padding: 0;
  list-style: none;
}

.page-about__cert-list li {
  position: relative;
  padding-left: 1.25rem;
  font-size: 0.875rem;
  color: var(--color-text-secondary);
}

.page-about__cert-list li::before {
  content: "";
  position: absolute;
  left: 2px;
  top: 0.45em;
  width: 8px;
  height: 8px;
  background: var(--color-gold);
  transform: rotate(45deg);
}

.page-about__cert-side {
  display: flex;
  flex-direction: column;
  gap: 1rem;
}

.page-about__cert-score {
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  padding: 1.5rem 1rem;
  text-align: center;
  border: 2px solid var(--color-gold);
  background: rgba(212, 175, 55, 0.12);
}

.page-about__cert-score-num {
  font-family: var(--font-head);
  font-size: 2.25rem;
  font-weight: 700;
  line-height: 1.1;
  color: var(--color-gold);
}

.page-about__cert-score-label {
  margin-top: 0.4rem;
  font-size: 0.85rem;
  color: rgba(255, 255, 255, 0.85);
}

.page-about__cert-detail {
  padding: 0.9rem 1rem;
  border: 1px solid rgba(255, 255, 255, 0.3);
  background: rgba(255, 255, 255, 0.06);
}

.page-about__cert-detail summary {
  display: inline-flex;
  align-items: center;
  gap: 0.4rem;
  cursor: pointer;
  list-style: none;
  color: var(--color-gold-light);
  font-size: 0.9rem;
  font-weight: 600;
}

.page-about__cert-detail summary::-webkit-details-marker {
  display: none;
}

.page-about__cert-detail summary::before {
  content: "+";
  font-weight: 700;
  color: var(--color-gold);
}

.page-about__cert-detail[open] summary::before {
  content: "–";
}

.page-about__cert-detail[open] summary {
  margin-bottom: 0.6rem;
}

.page-about__cert-detail p {
  margin: 0;
  font-size: 0.85rem;
  line-height: 1.6;
  color: rgba(255, 255, 255, 0.85);
}

/* ===== 团队与组织 ===== */
.page-about__team {
  background: var(--color-bg);
  padding: var(--space-xxl) 0;
}

.page-about__team-grid {
  display: grid;
  gap: 1.25rem;
}

.page-about__team-card {
  position: relative;
  padding: 1.5rem 1.5rem 1.5rem 4.6rem;
  background: var(--color-white);
  border: 2px solid var(--color-primary);
  box-shadow: var(--shadow-hard);
}

.page-about__team-card::after {
  content: "";
  position: absolute;
  top: 0;
  left: 0;
  width: 5px;
  height: 100%;
  background: var(--color-gold);
}

.page-about__team-count {
  position: absolute;
  top: 1.1rem;
  left: 1.1rem;
  padding-bottom: 0.3rem;
  border-bottom: 2px solid var(--color-primary);
  font-family: var(--font-head);
  font-size: 2.1rem;
  font-weight: 700;
  line-height: 1;
  color: var(--color-gold);
}

.page-about__team-role {
  margin: 0 0 0.3rem;
  font-size: 0.8rem;
  font-weight: 600;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  color: var(--color-teal);
}

.page-about__team-card h3 {
  margin: 0 0 0.5rem;
  font-family: var(--font-head);
  font-size: 1.05rem;
}

.page-about__team-card p:last-child {
  margin: 0;
  font-size: 0.875rem;
  line-height: 1.65;
  color: var(--color-text-secondary);
}

.page-about__team-note {
  margin-top: 1.5rem;
  padding: 1rem 1.25rem;
  background: var(--color-white);
  border-left: 4px solid var(--color-gold);
  box-shadow: var(--shadow-hard);
  font-size: 0.875rem;
  line-height: 1.65;
  color: var(--color-text-secondary);
}

.page-about__team-note a {
  color: var(--color-primary);
  text-decoration: underline;
  text-underline-offset: 3px;
}

.page-about__team-note a:hover {
  color: var(--color-teal);
}

/* ===== 内容日志 CTA ===== */
.page-about__journal {
  background: var(--color-white);
  padding: var(--space-xxl) 0;
}

.page-about__journal-inner {
  position: relative;
  display: flex;
  flex-direction: column;
  align-items: flex-start;
  gap: 1.25rem;
  padding: 2rem;
  background: var(--color-bg);
  border: 2px solid var(--color-primary);
  box-shadow: var(--shadow-hard);
}

.page-about__journal-inner::before {
  content: "";
  position: absolute;
  top: -2px;
  left: -2px;
  width: 90px;
  height: 6px;
  background: var(--color-gold);
}

.page-about__journal-copy h2 {
  margin: 0;
  font-family: var(--font-head);
  font-size: 1.5rem;
}

.page-about__journal-copy p {
  margin: 0.6rem 0 0;
  font-size: 0.9rem;
  line-height: 1.65;
  color: var(--color-text-secondary);
}

/* ===== 响应式 ===== */
@media (min-width: 768px) {
  .page-about__hero {
    padding: 4rem 0 3.5rem;
  }

  .page-about__hero-stats {
    gap: 1rem;
  }

  .page-about__stat {
    padding: 1.1rem;
  }

  .page-about__stat-num {
    font-size: 2.25rem;
  }

  .page-about__journey-figures {
    grid-template-columns: 1.2fr 0.8fr;
    align-items: stretch;
  }

  .page-about__philosophy-head {
    grid-template-columns: 1.1fr 0.9fr;
  }

  .page-about__principles {
    grid-template-columns: 1fr 1fr;
  }

  .page-about__cert-layout {
    grid-template-columns: 1.1fr 0.9fr;
  }

  .page-about__journal-inner {
    flex-direction: row;
    align-items: center;
    justify-content: space-between;
    padding: 2.5rem;
  }
}

@media (min-width: 900px) {
  .page-about__hero-inner {
    grid-template-columns: minmax(0, 1.1fr) minmax(0, 0.9fr);
    grid-template-areas:
      "copy nav"
      "stats nav";
    gap: 0 3rem;
  }

  .page-about__hero-copy {
    grid-area: copy;
  }

  .page-about__chapter-nav {
    grid-area: nav;
  }

  .page-about__hero-stats {
    grid-area: stats;
  }

  .page-about__milestone {
    width: auto;
    min-width: 300px;
    max-width: 320px;
  }

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