.page-about {
  --page-gold: #D4A017;
  --page-gold-light: #F0C75E;
  --page-gold-dark: #B8860B;
  --page-red: #8B0000;
  --page-bg-card: #2C2C2C;
  --page-text-secondary: #CCCCCC;

  display: flex;
  flex-direction: column;
  gap: 0;
  background: var(--bg-dark);
  color: var(--text-primary);
  padding: 0;
  margin: 0;
  width: 100%;
  overflow-x: hidden;
}

/* breadcrumb */
.page-about .breadcrumb {
  display: flex;
  align-items: center;
  gap: 0.5rem;
  font-family: var(--font-ui);
  font-size: 0.85rem;
  padding: 1rem 1.25rem;
  margin: 0 auto;
  max-width: var(--max-w);
  width: 100%;
  box-sizing: border-box;
}

.page-about .breadcrumb a {
  color: var(--link);
  text-decoration: none;
  transition: var(--transition);
}

.page-about .breadcrumb a:hover,
.page-about .breadcrumb a:focus {
  color: var(--page-gold-light);
  text-decoration: underline;
}

.page-about .breadcrumb .sep {
  color: var(--page-gold);
  margin: 0 0.25rem;
}

.page-about .breadcrumb span[aria-current="page"] {
  color: var(--text-secondary);
  font-weight: 600;
}

/* intro-split */
.page-about .intro-split {
  display: flex;
  flex-direction: column;
  max-width: var(--max-w);
  margin: 0 auto;
  padding: 1.25rem;
  gap: 2rem;
  box-sizing: border-box;
  width: 100%;
}

.page-about .intro-narrow {
  flex: 1 1 auto;
}

.page-about .intro-narrow .tag-gold {
  display: inline-block;
  font-family: var(--font-ui);
  font-size: 0.75rem;
  letter-spacing: 0.15em;
  color: var(--page-gold);
  border: 1px solid var(--page-gold);
  padding: 0.2em 0.6em;
  margin-bottom: 0.75rem;
}

.page-about .intro-narrow .section-title {
  margin-top: 0.5rem;
  margin-bottom: 1rem;
}

.page-about .intro-narrow .text {
  font-size: 1rem;
  line-height: 1.7;
  color: var(--page-text-secondary);
  margin-bottom: 1rem;
}

.page-about .intro-narrow .text:last-child {
  margin-bottom: 0;
}

.page-about .intro-wide {
  flex: 1 1 auto;
  position: relative;
  display: flex;
  align-items: center;
  justify-content: center;
}

.page-about .intro-image {
  width: 100%;
  max-width: 600px;
  height: auto;
  object-fit: contain;
  border-radius: var(--radius-lg);
  box-shadow: var(--shadow-gold);
  position: relative;
  z-index: 2;
  display: block;
  transition: box-shadow 0.3s ease;
}

.page-about .intro-image:hover,
.page-about .intro-image:focus {
  box-shadow: 0 0 40px 12px rgba(212, 160, 23, 0.5), var(--shadow-gold);
}

.page-about .golden-ring {
  position: absolute;
  top: 50%;
  left: 50%;
  width: 90%;
  padding-bottom: 90%;
  transform: translate(-50%, -50%);
  border-radius: 50%;
  border: 2px solid rgba(212, 160, 23, 0.2);
  pointer-events: none;
  z-index: 0;
  animation: pulse-ring 4s ease-in-out infinite;
}

@keyframes pulse-ring {
  0%, 100% { border-color: rgba(212, 160, 23, 0.15); transform: translate(-50%, -50%) scale(1); }
  50% { border-color: rgba(212, 160, 23, 0.35); transform: translate(-50%, -50%) scale(1.05); }
}

/* philosophy block */
.page-about .philosophy-block {
  max-width: var(--max-w);
  margin: 2rem auto 0;
  padding: 0 1.25rem;
  box-sizing: border-box;
  width: 100%;
}

.page-about .philosophy-card {
  background: var(--bg-card);
  border-left: 4px solid var(--page-gold);
  padding: 2rem 1.5rem;
  border-radius: 0 var(--radius-lg) var(--radius-lg) 0;
  display: flex;
  flex-direction: column;
  gap: 1.25rem;
  box-shadow: var(--shadow-card);
}

.page-about .philosophy-card .section-title {
  margin: 0;
}

.page-about .philosophy-card .text {
  font-size: 1rem;
  line-height: 1.7;
  color: var(--page-text-secondary);
  margin: 0;
}

.page-about .philosophy-visual {
  margin-top: 0.75rem;
}

.page-about .philosophy-img {
  width: 100%;
  max-width: 400px;
  height: auto;
  object-fit: contain;
  border-radius: var(--radius);
  box-shadow: 0 4px 16px rgba(0,0,0,0.5);
  display: block;
}

/* community block */
.page-about .community-block {
  display: flex;
  flex-direction: column;
  gap: 1.5rem;
  max-width: var(--max-w);
  margin: 2rem auto 0;
  padding: 0 1.25rem;
  box-sizing: border-box;
  width: 100%;
}

.page-about .community-text {
  flex: 1 1 auto;
}

.page-about .community-text .section-title {
  margin-top: 0;
  margin-bottom: 1rem;
}

.page-about .community-text .text {
  font-size: 1rem;
  line-height: 1.7;
  color: var(--page-text-secondary);
  margin-bottom: 1rem;
}

.page-about .community-text .link {
  color: var(--link);
  text-decoration: none;
  border-bottom: 1px dotted var(--page-gold);
  transition: var(--transition);
}

.page-about .community-text .link:hover,
.page-about .community-text .link:focus {
  color: var(--page-gold-light);
  border-bottom-style: solid;
}

.page-about .community-visual {
  flex: 1 1 auto;
}

.page-about .community-img {
  width: 100%;
  max-width: 500px;
  height: auto;
  object-fit: contain;
  border-radius: var(--radius-lg);
  box-shadow: var(--shadow-card);
  display: block;
}

/* timeline block */
.page-about .timeline-block {
  max-width: var(--max-w);
  margin: 2rem auto 0;
  padding: 0 1.25rem 2rem;
  box-sizing: border-box;
  width: 100%;
}

.page-about .timeline-block .section-title {
  margin-bottom: 2rem;
}

.page-about .timeline-grid {
  display: flex;
  flex-direction: column;
  gap: 1.5rem;
  position: relative;
}

.page-about .timeline-grid::before {
  content: '';
  position: absolute;
  top: 0;
  left: 1.5rem;
  bottom: 0;
  width: 2px;
  background: linear-gradient(to bottom, var(--page-gold), var(--page-gold-dark), transparent);
  z-index: 0;
}

.page-about .timeline-item {
  position: relative;
  z-index: 1;
  padding-left: 4rem;
  background: var(--bg-card);
  border-radius: var(--radius);
  padding: 1rem 1.25rem 1rem 4rem;
  border: 1px solid rgba(212, 160, 23, 0.25);
  transition: var(--transition);
}

.page-about .timeline-item:hover,
.page-about .timeline-item:focus-within {
  border-color: var(--page-gold);
  box-shadow: 0 0 20px rgba(212, 160, 23, 0.15);
  transform: translateX(4px);
}

.page-about .timeline-item::before {
  content: attr(data-index);
  position: absolute;
  left: 0.75rem;
  top: 50%;
  transform: translateY(-50%);
  font-family: var(--font-ui);
  font-size: 1.25rem;
  font-weight: 700;
  color: var(--page-gold);
  width: 2rem;
  height: 2rem;
  display: flex;
  align-items: center;
  justify-content: center;
  border-radius: 50%;
  background: var(--bg-dark);
  border: 2px solid var(--page-gold);
  z-index: 2;
}

.page-about .timeline-item .tag-gold {
  display: inline-block;
  font-family: var(--font-ui);
  font-size: 0.75rem;
  letter-spacing: 0.1em;
  color: var(--page-gold);
  border: 1px solid var(--page-gold);
  padding: 0.15em 0.5em;
  margin-bottom: 0.5rem;
}

.page-about .timeline-item .text {
  font-size: 0.95rem;
  line-height: 1.6;
  color: var(--page-text-secondary);
  margin: 0;
}

/* trust statement */
.page-about .trust-statement {
  max-width: var(--max-w);
  margin: 0 auto;
  padding: 1.5rem 1.25rem 2.5rem;
  box-sizing: border-box;
  width: 100%;
}

.page-about .trust-statement .text {
  font-size: 0.85rem;
  color: var(--text-secondary);
  border-top: 1px solid rgba(212, 160, 23, 0.2);
  padding-top: 1.25rem;
  max-width: 560px;
  margin-left: auto;
  margin-right: auto;
}

/* container helper */
.page-about .container {
  max-width: var(--max-w);
  margin-left: auto;
  margin-right: auto;
  width: 100%;
  box-sizing: border-box;
}

/* text-center */
.page-about .text-center {
  text-align: center;
}

/* common heading */
.page-about .section-title {
  font-family: 'Noto Serif SC', serif;
  font-weight: 700;
  font-size: 1.75rem;
  letter-spacing: 0.02em;
  color: var(--page-gold);
  display: flex;
  align-items: center;
  gap: 0.5rem;
}

.page-about .section-title .index {
  font-family: var(--font-ui);
  font-size: 1rem;
  color: var(--page-gold-dark);
  opacity: 0.6;
}

/* ===== 桌面端 (min-width: 768px) ===== */
@media (min-width: 768px) {
  .page-about .breadcrumb {
    padding: 1.25rem 2rem;
  }

  .page-about .intro-split {
    flex-direction: row;
    padding: 2rem;
    gap: 3rem;
  }

  .page-about .intro-narrow {
    flex: 1 1 40%;
  }

  .page-about .intro-wide {
    flex: 1 1 60%;
  }

  .page-about .intro-image {
    max-width: 600px;
  }

  .page-about .philosophy-block {
    padding: 0 2rem;
  }

  .page-about .philosophy-card {
    flex-direction: row;
    flex-wrap: wrap;
    padding: 2.5rem 2rem;
  }

  .page-about .philosophy-card .section-title {
    width: 100%;
    font-size: 2rem;
  }

  .page-about .philosophy-card .text {
    flex: 1 1 45%;
  }

  .page-about .philosophy-visual {
    flex: 1 1 100%;
  }

  .page-about .philosophy-img {
    max-width: 400px;
  }

  .page-about .community-block {
    flex-direction: row;
    padding: 2rem;
    gap: 3rem;
  }

  .page-about .community-text {
    flex: 1 1 50%;
  }

  .page-about .community-visual {
    flex: 1 1 50%;
  }

  .page-about .community-img {
    max-width: 500px;
  }

  .page-about .timeline-block {
    padding: 0 2rem 3rem;
  }

  .page-about .timeline-grid {
    display: grid;
    grid-template-columns: repeat(4, 1fr);
    gap: 1.5rem;
  }

  .page-about .timeline-grid::before {
    display: none;
  }

  .page-about .timeline-item {
    padding: 1.5rem 1.5rem 1.5rem 4rem;
  }

  .page-about .timeline-item::before {
    left: 0.75rem;
  }

  .page-about .section-title {
    font-size: 2rem;
  }

  .page-about .trust-statement {
    padding: 2rem 2rem 3rem;
  }
}