/* ===== 页面专属 CSS — .page-about ===== */
.page-about {
  --brand-gradient: linear-gradient(135deg, var(--color-orange), var(--color-green));
  --cut-size: 24px;
  --card-min-height: 380px;
  display: block;
  width: 100%;
}

/* ---------- 品牌档案区 ---------- */
.page-about .brand-story {
  position: relative;
  overflow: hidden;
  min-height: 520px;
  display: flex;
  align-items: center;
  background-color: var(--color-blue);
  padding: 4rem 0 3rem;
  color: var(--color-white);
}

.page-about .brand-bg-wrap {
  position: absolute;
  inset: 0;
  z-index: 0;
  overflow: hidden;
}

.page-about .brand-bg-img {
  width: 100%;
  height: 100%;
  object-fit: cover;
  object-position: center 30%;
  display: block;
}

.page-about .brand-overlay {
  position: absolute;
  inset: 0;
  background: linear-gradient(110deg, rgba(0,51,102,.88) 40%, rgba(0,51,102,.55) 80%, rgba(0,51,102,.3) 100%);
  z-index: 1;
}

.page-about .brand-content {
  position: relative;
  z-index: 2;
  max-width: 820px;
}

.page-about .breadcrumb {
  display: flex;
  align-items: center;
  gap: 0.5rem;
  font-size: 0.875rem;
  font-family: var(--font-body);
  color: rgba(255,255,255,.7);
  margin-bottom: 1.5rem;
}

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

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

.page-about .breadcrumb .sep {
  color: rgba(255,255,255,.4);
}

.page-about .brand-label {
  display: inline-block;
  font-family: var(--font-data);
  font-size: 0.75rem;
  letter-spacing: .15em;
  text-transform: uppercase;
  color: var(--color-green);
  border: 1px solid var(--color-green);
  padding: 0.25rem 0.75rem;
  margin-bottom: 1rem;
  border-radius: 2px;
}

.page-about .brand-headline {
  font-family: var(--font-heading);
  font-weight: 800;
  font-size: clamp(1.75rem, 5.5vw, 3rem);
  line-height: 1.15;
  margin: 0 0 1rem;
  letter-spacing: -0.02em;
}

.page-about .brand-accent {
  background: var(--brand-gradient);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
  display: inline-block;
}

.page-about .brand-desc {
  font-family: var(--font-body);
  font-size: clamp(1rem, 2vw, 1.125rem);
  line-height: 1.7;
  color: rgba(255,255,255,.9);
  max-width: 640px;
  margin: 0 0 2rem;
}

.page-about .brand-actions {
  display: flex;
  flex-wrap: wrap;
  gap: 1rem;
}

.page-about .brand-actions .btn-primary {
  background: var(--color-orange);
  border: 2px solid var(--color-orange);
  color: var(--color-white);
  padding: 0.75rem 1.75rem;
  font-family: var(--font-heading);
  font-weight: 700;
  font-size: 0.95rem;
  border-radius: var(--radius);
  text-decoration: none;
  transition: var(--transition);
}

.page-about .brand-actions .btn-primary:hover,
.page-about .brand-actions .btn-primary:focus-visible {
  background: transparent;
  color: var(--color-orange);
  transform: translateY(-2px);
  box-shadow: 0 8px 24px rgba(255,107,53,.3);
}

.page-about .brand-actions .btn-outline {
  background: transparent;
  border: 2px solid rgba(255,255,255,.6);
  color: var(--color-white);
  padding: 0.75rem 1.75rem;
  font-family: var(--font-heading);
  font-weight: 600;
  font-size: 0.95rem;
  border-radius: var(--radius);
  text-decoration: none;
  transition: var(--transition);
}

.page-about .brand-actions .btn-outline:hover,
.page-about .brand-actions .btn-outline:focus-visible {
  border-color: var(--color-white);
  background: rgba(255,255,255,.08);
  transform: translateY(-2px);
}

/* ---------- 核心服务区 ---------- */
.page-about .core-services {
  background: var(--color-bg-warm);
  padding: 4rem 0;
}

.page-about .section-title {
  font-family: var(--font-heading);
  font-weight: 800;
  font-size: clamp(1.5rem, 4vw, 2.25rem);
  line-height: 1.2;
  color: var(--color-text);
  margin: 0 0 0.5rem;
  letter-spacing: -0.02em;
}

.page-about .section-subtitle {
  font-family: var(--font-body);
  font-size: 1rem;
  color: #666;
  margin: 0 0 2.5rem;
  line-height: 1.6;
}

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

.page-about .service-card {
  background: var(--color-white);
  border-radius: var(--radius);
  overflow: hidden;
  box-shadow: var(--shadow-card);
  transition: var(--transition);
  display: flex;
  flex-direction: column;
  min-height: var(--card-min-height);
  clip-path: polygon(0 0, calc(100% - var(--cut-size)) 0, 100% var(--cut-size), 100% 100%, 0 100%);
}

.page-about .service-card:hover,
.page-about .service-card:focus-within {
  box-shadow: var(--shadow-hover);
  transform: translateY(-6px);
}

.page-about .card-img-wrap {
  width: 100%;
  aspect-ratio: 1 / 1;
  overflow: hidden;
  background: var(--color-blue-dark);
}

.page-about .card-img-wrap img {
  width: 100%;
  height: 100%;
  object-fit: cover;
  display: block;
  transition: transform .4s ease;
}

.page-about .service-card:hover .card-img-wrap img {
  transform: scale(1.05);
}

.page-about .card-body {
  padding: 1.25rem 1.5rem 1.5rem;
  flex: 1;
  display: flex;
  flex-direction: column;
}

.page-about .card-icon {
  font-size: 1.75rem;
  line-height: 1;
  margin-bottom: 0.5rem;
}

.page-about .card-title {
  font-family: var(--font-heading);
  font-weight: 700;
  font-size: 1.25rem;
  color: var(--color-blue);
  margin: 0 0 0.5rem;
}

.page-about .card-desc {
  font-family: var(--font-body);
  font-size: 0.95rem;
  line-height: 1.6;
  color: #444;
  margin: 0 0 0.75rem;
  flex: 1;
}

.page-about .card-detail {
  font-family: var(--font-body);
  font-size: 0.85rem;
  line-height: 1.5;
  color: var(--color-orange);
  margin: 0;
  max-height: 0;
  overflow: hidden;
  transition: max-height .35s ease, opacity .35s ease;
  opacity: 0;
}

.page-about .service-card:hover .card-detail,
.page-about .service-card:focus-within .card-detail {
  max-height: 80px;
  opacity: 1;
}

.page-about .service-divider {
  display: none;
}

/* ---------- 技术承诺区 ---------- */
.page-about .tech-commitment {
  background: var(--color-blue-dark);
  padding: 4rem 0;
  color: var(--color-white);
}

.page-about .tech-commitment .section-title {
  color: var(--color-white);
}

.page-about .tech-commitment .section-subtitle {
  color: rgba(255,255,255,.7);
}

.page-about .tech-grid {
  display: flex;
  flex-direction: column;
  gap: 2rem;
}

.page-about .tech-item {
  display: flex;
  flex-direction: column;
  gap: 0.25rem;
  padding: 1.5rem;
  background: rgba(255,255,255,.04);
  border-left: 3px solid var(--color-orange);
  border-radius: 0 var(--radius) var(--radius) 0;
  transition: var(--transition);
}

.page-about .tech-item:hover {
  background: rgba(255,255,255,.08);
  transform: translateX(4px);
}

.page-about .tech-version {
  font-family: var(--font-data);
  font-size: 2.25rem;
  font-weight: 700;
  color: var(--color-green);
  line-height: 1.1;
  letter-spacing: -0.02em;
  cursor: default;
  position: relative;
  display: inline-block;
  width: fit-content;
}

.page-about .tech-version::after {
  content: "↗";
  font-size: 1rem;
  color: rgba(255,255,255,.3);
  position: relative;
  top: -0.5rem;
  left: 0.25rem;
  transition: var(--transition);
}

.page-about .tech-version:hover::after {
  color: var(--color-green);
}

.page-about .tech-icon {
  font-family: var(--font-data);
  font-size: 2rem;
  color: var(--color-orange);
  line-height: 1;
}

.page-about .tech-label {
  font-family: var(--font-heading);
  font-weight: 700;
  font-size: 1.125rem;
  color: var(--color-white);
  margin-top: 0.25rem;
}

.page-about .tech-desc {
  font-family: var(--font-body);
  font-size: 0.95rem;
  line-height: 1.6;
  color: rgba(255,255,255,.75);
  margin: 0;
}

/* ---------- 联系我们区 ---------- */
.page-about .contact-section {
  background: var(--color-white);
  padding: 4rem 0;
}

.page-about .contact-grid {
  display: flex;
  flex-direction: column;
  gap: 1.5rem;
  margin-bottom: 2rem;
}

.page-about .contact-item {
  background: var(--color-bg-warm);
  border-radius: var(--radius);
  padding: 1.5rem;
  display: flex;
  flex-direction: column;
  gap: 0.25rem;
  transition: var(--transition);
  border: 1px solid transparent;
}

.page-about .contact-item:hover {
  border-color: var(--color-orange-light);
  box-shadow: 0 4px 16px rgba(255,107,53,.08);
}

.page-about .contact-icon {
  font-size: 1.5rem;
  line-height: 1;
  margin-bottom: 0.25rem;
}

.page-about .contact-label {
  font-family: var(--font-heading);
  font-weight: 700;
  font-size: 0.9rem;
  color: var(--color-blue);
  margin: 0;
}

.page-about .contact-link {
  font-family: var(--font-data);
  font-size: 1rem;
  color: var(--color-orange);
  text-decoration: none;
  transition: var(--transition);
  word-break: break-all;
}

.page-about .contact-link:hover,
.page-about .contact-link:focus-visible {
  color: var(--color-blue);
  text-decoration: underline;
}

.page-about .contact-value {
  font-family: var(--font-body);
  font-size: 1rem;
  color: var(--color-text);
}

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

.page-about .contact-note {
  font-family: var(--font-body);
  font-size: 0.9rem;
  line-height: 1.6;
  color: #666;
  background: rgba(0,51,102,.04);
  padding: 1rem 1.25rem;
  border-radius: var(--radius);
  border-left: 3px solid var(--color-green);
  margin: 0;
}

/* ---------- 桌面端 (≥768px) ---------- */
@media (min-width: 768px) {
  .page-about .brand-story {
    min-height: 600px;
    padding: 5rem 0 4rem;
  }

  .page-about .brand-content {
    max-width: 720px;
  }

  .page-about .services-grid {
    flex-direction: row;
    align-items: stretch;
    gap: 0;
    position: relative;
  }

  .page-about .service-card {
    flex: 1;
    margin: 0 0.75rem;
  }

  .page-about .service-divider {
    display: block;
    width: 2px;
    min-height: 200px;
    align-self: center;
    background: linear-gradient(180deg, var(--color-orange), var(--color-blue));
    transform: skewX(-12deg);
    border-radius: 2px;
    flex-shrink: 0;
    opacity: 0.5;
  }

  .page-about .service-card:first-child {
    margin-left: 0;
  }

  .page-about .service-card:last-child {
    margin-right: 0;
  }

  .page-about .tech-grid {
    flex-direction: row;
    gap: 1.5rem;
  }

  .page-about .tech-item {
    flex: 1;
  }

  .page-about .contact-grid {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 1.5rem;
  }

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

/* ---------- 大桌面端 (≥1024px) ---------- */
@media (min-width: 1024px) {
  .page-about .brand-story {
    min-height: 680px;
    padding: 6rem 0 5rem;
  }

  .page-about .brand-headline {
    font-size: 3.25rem;
  }

  .page-about .services-grid {
    gap: 0;
  }

  .page-about .service-card {
    margin: 0 1rem;
  }

  .page-about .service-divider {
    min-height: 260px;
  }

  .page-about .tech-grid {
    gap: 2rem;
  }

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

  .page-about .contact-item--wide {
    grid-column: auto;
  }
}