.page-about {
  --page-accent: #FF7A00;
  --page-primary: #0F1B2D;
  --page-teal: #1A4A5A;
  --page-wine: #8B2252;
  --page-white: #FFFFFF;
  --page-light-gray: #F4F4F4;
  --page-dark-gray: #333333;
  --page-text-on-dark: #E0E0E0;
  --page-font-heading: 'Segoe UI', Roboto, Helvetica, Arial, sans-serif;
  --page-font-body: 'Segoe UI', Roboto, Helvetica, Arial, sans-serif;
  --page-font-data: 'Courier New', Consolas, monospace;
  --page-radius-sm: 4px;
  --page-radius-md: 8px;
  --page-radius-lg: 12px;
  --page-transition: 0.3s ease;
  --page-content-width: min(1200px, 100% - 2rem);

  max-width: var(--page-content-width);
  margin: 0 auto;
  padding: 0 1rem 3rem;
  font-family: var(--page-font-body);
  color: var(--page-dark-gray);
  line-height: 1.6;
}

/* ========================================
   面包屑
   ======================================== */
.page-about .breadcrumb {
  display: flex;
  align-items: center;
  gap: 0.4rem;
  padding: 1.25rem 0 0.5rem;
  font-size: 0.85rem;
  color: var(--page-text-on-dark);
  opacity: 0.7;
}

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

.page-about .breadcrumb a:hover,
.page-about .breadcrumb a:focus-visible {
  opacity: 0.75;
  text-decoration: underline;
}

.page-about .breadcrumb .separator {
  color: var(--page-text-on-dark);
  opacity: 0.5;
}

.page-about .breadcrumb [aria-current="page"] {
  color: var(--page-white);
  opacity: 0.9;
}

/* ========================================
   通用标题/描述
   ======================================== */
.page-about .section-heading {
  font-family: var(--page-font-heading);
  font-weight: 800;
  font-size: clamp(1.6rem, 3.5vw, 2.4rem);
  color: var(--page-white);
  margin: 0 0 0.4rem;
  letter-spacing: -0.02em;
}

.page-about .section-desc {
  font-size: 1rem;
  color: var(--page-text-on-dark);
  opacity: 0.85;
  max-width: 600px;
  margin: 0 0 1.5rem;
}

.page-about .badge {
  display: inline-block;
  background: var(--page-accent);
  color: var(--page-white);
  font-size: 0.7rem;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 0.08em;
  padding: 0.2rem 0.6rem;
  border-radius: var(--page-radius-sm);
  margin-bottom: 0.6rem;
}

/* ========================================
   首屏框景 —— 切角面板
   ======================================== */
.page-about .hero {
  position: relative;
  display: grid;
  grid-template-columns: 1fr;
  gap: 1.5rem;
  padding: 2rem 1.5rem 2.5rem;
  margin: 0.5rem 0 2.5rem;
  background: var(--page-primary);
  border-radius: var(--page-radius-lg);
  overflow: hidden;
  clip-path: polygon(0 0, 100% 0, 100% calc(100% - 18px), calc(100% - 18px) 100%, 0 100%);
}

.page-about .hero__content {
  position: relative;
  z-index: 2;
}

.page-about .hero__title {
  font-family: var(--page-font-heading);
  font-weight: 800;
  font-size: clamp(1.8rem, 4vw, 2.8rem);
  color: var(--page-white);
  margin: 0 0 0.6rem;
  line-height: 1.15;
  letter-spacing: -0.02em;
}

.page-about .hero__subtitle {
  font-size: 1.05rem;
  font-weight: 500;
  color: var(--page-accent);
  margin: 0 0 0.8rem;
  padding: 0.4rem 0 0.4rem 0.8rem;
  border-left: 3px solid var(--page-accent);
}

.page-about .hero__text {
  font-size: 0.95rem;
  color: var(--page-text-on-dark);
  max-width: 480px;
  margin: 0 0 1.4rem;
  opacity: 0.9;
}

.page-about .hero__actions {
  display: flex;
  flex-wrap: wrap;
  gap: 0.8rem;
}

.page-about .btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  padding: 0.55rem 1.4rem;
  font-size: 0.9rem;
  font-weight: 600;
  border-radius: var(--page-radius-md);
  text-decoration: none;
  transition: all var(--page-transition);
  cursor: default;
  border: 2px solid transparent;
}

.page-about .btn-primary {
  background: var(--page-accent);
  color: var(--page-white);
  border-color: var(--page-accent);
}

.page-about .btn-primary:hover,
.page-about .btn-primary:focus-visible {
  background: transparent;
  color: var(--page-accent);
}

.page-about .btn-secondary {
  background: transparent;
  color: var(--page-white);
  border-color: var(--page-white);
}

.page-about .btn-secondary:hover,
.page-about .btn-secondary:focus-visible {
  background: var(--page-white);
  color: var(--page-primary);
}

.page-about .hero__visual {
  position: relative;
  z-index: 2;
}

.page-about .hero__img {
  width: 100%;
  max-width: 100%;
  height: auto;
  border-radius: var(--page-radius-md);
  object-fit: cover;
  display: block;
  box-shadow: 0 4px 24px rgba(0,0,0,0.35);
}

.page-about .hero__deco {
  position: absolute;
  inset: 0;
  z-index: 1;
  pointer-events: none;
  background:
    linear-gradient(135deg, rgba(255,122,0,0.08) 0%, transparent 50%),
    repeating-linear-gradient(45deg, transparent, transparent 18px, rgba(255,255,255,0.02) 18px, rgba(255,255,255,0.02) 19px);
}

/* ========================================
   品牌起源 —— 时间轴
   ======================================== */
.page-about .origin {
  padding: 2.5rem 0 1.5rem;
  border-top: 1px solid rgba(255,255,255,0.08);
}

.page-about .origin__header {
  margin-bottom: 2rem;
}

.page-about .timeline {
  position: relative;
  display: flex;
  flex-direction: column;
  gap: 0;
  padding-left: 2rem;
}

.page-about .timeline::before {
  content: '';
  position: absolute;
  top: 0;
  bottom: 0;
  left: 6px;
  width: 2px;
  background: var(--page-accent);
  opacity: 0.35;
}

.page-about .timeline__node {
  position: relative;
  border-bottom: 1px solid rgba(255,255,255,0.06);
  padding: 0.6rem 0;
}

.page-about .timeline__node:last-of-type {
  border-bottom: none;
}

.page-about .timeline__node-header {
  display: flex;
  align-items: center;
  gap: 0.75rem;
  cursor: pointer;
  padding: 0.5rem 0;
  user-select: none;
  transition: background var(--page-transition);
  border-radius: var(--page-radius-sm);
}

.page-about .timeline__node-header:hover {
  background: rgba(255,122,0,0.06);
}

.page-about .timeline__node-marker {
  flex-shrink: 0;
  width: 14px;
  height: 14px;
  border-radius: 50%;
  background: var(--page-accent);
  border: 3px solid var(--page-primary);
  box-shadow: 0 0 0 2px var(--page-accent);
  position: relative;
  z-index: 1;
}

.page-about .timeline__node-title {
  font-family: var(--page-font-heading);
  font-weight: 700;
  font-size: 1.1rem;
  color: var(--page-white);
  margin: 0;
  flex: 1;
}

.page-about .timeline__node-icon {
  flex-shrink: 0;
  font-size: 1.2rem;
  font-weight: 300;
  color: var(--page-accent);
  transition: transform var(--page-transition);
  width: 1.5rem;
  text-align: center;
}

.page-about .timeline__node[data-expanded="true"] .timeline__node-icon {
  transform: rotate(45deg);
}

.page-about .timeline__node-body {
  display: grid;
  grid-template-rows: 0fr;
  transition: grid-template-rows 0.4s ease;
  padding-left: 1.8rem;
  overflow: hidden;
}

.page-about .timeline__node-body > * {
  min-height: 0;
}

.page-about .timeline__node[data-expanded="true"] .timeline__node-body {
  grid-template-rows: 1fr;
}

.page-about .timeline__node-body p {
  margin: 0.5rem 0 0.8rem;
  color: var(--page-text-on-dark);
  font-size: 0.92rem;
  opacity: 0.9;
  max-width: 680px;
}

.page-about .timeline__img {
  width: 100%;
  max-width: 100%;
  height: auto;
  border-radius: var(--page-radius-md);
  object-fit: cover;
  margin: 0.4rem 0 0.8rem;
  display: block;
}

/* ========================================
   数据价值 —— 卡片网格
   ======================================== */
.page-about .value {
  padding: 2.5rem 0;
  border-top: 1px solid rgba(255,255,255,0.08);
}

.page-about .value__header {
  margin-bottom: 1.8rem;
}

.page-about .value__grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: 1rem;
  margin-bottom: 2rem;
}

.page-about .data-card {
  background: var(--page-primary);
  border-radius: var(--page-radius-md);
  padding: 1.4rem 1.2rem;
  color: var(--page-white);
  transition: transform var(--page-transition), box-shadow var(--page-transition);
}

.page-about .data-card:hover {
  transform: translateY(-3px);
  box-shadow: 0 8px 32px rgba(0,0,0,0.3);
}

.page-about .data-card--dark {
  background: var(--page-teal);
}

.page-about .value__card {
  clip-path: polygon(0 0, 100% 0, 100% calc(100% - 10px), calc(100% - 10px) 100%, 0 100%);
}

.page-about .value__card--wide {
  grid-column: 1 / -1;
}

.page-about .value__stat {
  font-family: var(--page-font-data);
  font-weight: 700;
  font-size: clamp(2rem, 4.5vw, 3rem);
  color: var(--page-accent);
  margin: 0.2rem 0 0.2rem;
  line-height: 1.1;
  letter-spacing: -0.03em;
}

.page-about .value__unit {
  font-size: 0.6em;
  font-weight: 400;
  color: var(--page-text-on-dark);
  margin-left: 0.15rem;
  vertical-align: super;
}

.page-about .value__label {
  font-family: var(--page-font-heading);
  font-weight: 700;
  font-size: 0.95rem;
  color: var(--page-white);
  margin: 0 0 0.3rem;
}

.page-about .value__note {
  font-size: 0.85rem;
  color: var(--page-text-on-dark);
  opacity: 0.8;
  margin: 0;
  max-width: 360px;
}

.page-about .value__visual {
  margin-top: 1.5rem;
}

.page-about .value__img {
  width: 100%;
  max-width: 100%;
  height: auto;
  border-radius: var(--page-radius-md);
  object-fit: cover;
  display: block;
  box-shadow: 0 4px 20px rgba(0,0,0,0.25);
}

/* ========================================
   品牌承诺 CTA
   ======================================== */
.page-about .commitment {
  background: linear-gradient(135deg, var(--page-primary) 0%, #0a1424 100%);
  padding: 2.5rem 1.8rem;
  border-radius: var(--page-radius-lg);
  text-align: center;
  margin: 2rem 0 0.5rem;
  clip-path: polygon(0 0, 100% 0, 100% calc(100% - 18px), calc(100% - 18px) 100%, 0 100%);
  border: 1px solid rgba(255,122,0,0.15);
}

.page-about .commitment__title {
  font-family: var(--page-font-heading);
  font-weight: 800;
  font-size: clamp(1.5rem, 3vw, 2.2rem);
  color: var(--page-white);
  margin: 0 0 0.8rem;
  letter-spacing: -0.02em;
}

.page-about .commitment__text {
  font-size: 1rem;
  color: var(--page-text-on-dark);
  max-width: 560px;
  margin: 0 auto 1.5rem;
  opacity: 0.9;
}

.page-about .commitment__actions {
  display: flex;
  flex-wrap: wrap;
  justify-content: center;
  gap: 0.8rem;
}

/* ========================================
   窄屏适配（移动端优先）
   ======================================== */
@media (max-width: 639px) {
  .page-about {
    padding: 0 0.75rem 2rem;
  }

  .page-about .hero {
    padding: 1.5rem 1rem 2rem;
    gap: 1.2rem;
  }

  .page-about .hero__title {
    font-size: 1.5rem;
  }

  .page-about .hero__subtitle {
    font-size: 0.9rem;
    padding-left: 0.6rem;
  }

  .page-about .hero__text {
    font-size: 0.88rem;
  }

  .page-about .hero__actions {
    flex-direction: column;
  }

  .page-about .btn {
    width: 100%;
    text-align: center;
  }

  .page-about .timeline {
    padding-left: 1.4rem;
  }

  .page-about .timeline__node-title {
    font-size: 0.95rem;
  }

  .page-about .timeline__node-body p {
    font-size: 0.85rem;
  }

  .page-about .value__grid {
    gap: 0.8rem;
  }

  .page-about .data-card {
    padding: 1rem 0.9rem;
  }

  .page-about .value__stat {
    font-size: 1.8rem;
  }

  .page-about .commitment {
    padding: 1.8rem 1rem;
  }
}

/* ========================================
   宽屏适配（桌面栅格）
   ======================================== */
@media (min-width: 640px) {
  .page-about .hero {
    grid-template-columns: 1fr 1fr;
    align-items: center;
    padding: 2.5rem 2rem 3rem;
  }

  .page-about .hero__content {
    padding-right: 0.8rem;
  }

  .page-about .hero__visual {
    display: flex;
    justify-content: flex-end;
  }

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

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

  .page-about .value__card--wide {
    grid-column: 1 / -1;
  }

  .page-about .value__visual {
    display: flex;
    justify-content: center;
  }

  .page-about .value__img {
    max-width: 560px;
  }
}

@media (min-width: 1024px) {
  .page-about .hero {
    padding: 3rem 3rem 3.5rem;
  }

  .page-about .hero__img {
    max-width: 480px;
  }

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

  .page-about .value__card--wide {
    grid-column: span 2;
  }

  .page-about .timeline__node-body p {
    font-size: 0.96rem;
  }
}

/* ========================================
   焦点 & 可访问性
   ======================================== */
.page-about a:focus-visible,
.page-about [role="button"]:focus-visible,
.page-about button:focus-visible {
  outline: 2px solid var(--page-accent);
  outline-offset: 3px;
}

/* ========================================
   斜线装饰（has-diagonal 模式）
   ======================================== */
.page-about .has-diagonal {
  position: relative;
}

.page-about .has-diagonal::after {
  content: '';
  position: absolute;
  bottom: 0;
  right: 0;
  width: 60px;
  height: 60px;
  background: linear-gradient(135deg, transparent 50%, var(--page-accent) 50%);
  opacity: 0.12;
  pointer-events: none;
}