/* =============================================
   关于我们 页面专属样式
   作用域：.page-about
   ============================================= */
.page-about {
  --about-grid-line: rgba(44, 60, 78, 0.2);
  --about-card-alpha: rgba(28, 34, 43, 0.88);
  --about-diamond: 10px;
  --about-tl-gutter: 30px;
  position: relative;
  background-color: var(--j-bg);
  background-image:
    linear-gradient(to bottom, var(--about-grid-line) 1px, transparent 1px),
    linear-gradient(to right, var(--about-grid-line) 1px, transparent 1px);
  background-size: 48px 48px;
}

.page-about .container {
  max-width: var(--content-max);
  margin: 0 auto;
  padding: 0 var(--space-md);
}

/* ---- 面包屑 ---- */
.page-about .about-breadcrumb {
  display: flex;
  align-items: center;
  flex-wrap: wrap;
  gap: 10px;
  padding: var(--space-lg) 0 var(--space-md);
  font-size: 13px;
  letter-spacing: 0.02em;
}

.page-about .about-breadcrumb .breadcrumb-item {
  color: var(--j-muted);
  text-decoration: none;
  transition: color 0.2s ease;
}

.page-about .about-breadcrumb .breadcrumb-item:hover {
  color: var(--j-blue);
}

.page-about .about-breadcrumb .breadcrumb-item--active {
  color: var(--j-text);
  font-weight: 600;
}

.page-about .about-breadcrumb .breadcrumb-sep {
  color: #556070;
}

/* ---- 章节预览 ---- */
.page-about .about-index {
  display: grid;
  grid-template-columns: 1fr;
  gap: 10px;
  padding: var(--space-md) 0 var(--space-lg);
  margin-bottom: var(--space-md);
  border-bottom: 1px solid var(--j-border);
}

.page-about .about-index-chip {
  display: flex;
  align-items: baseline;
  gap: 10px;
  background: var(--about-card-alpha);
  border: 1px solid var(--j-border);
  padding: 12px 14px;
  text-decoration: none;
  color: var(--j-text);
  font-family: var(--j-font-body);
  font-size: 14px;
  font-weight: 500;
  letter-spacing: 0.02em;
  transition: border-color 0.2s ease, background-color 0.2s ease, transform 0.2s ease;
}

.page-about .about-index-chip span {
  font-family: var(--j-font-mono);
  font-size: 12px;
  color: var(--j-orange);
  font-weight: 700;
}

.page-about .about-index-chip:hover {
  border-color: var(--j-blue);
  background-color: rgba(10, 110, 189, 0.1);
  transform: translateY(-2px);
}

/* ---- 章节通用 ---- */
.page-about .section {
  padding: var(--space-xl) 0;
  scroll-margin-top: calc(var(--header-h) + 16px);
}

.page-about .section-header {
  margin-bottom: var(--space-lg);
}

.page-about .section-title {
  font-family: var(--j-font-display);
  font-size: clamp(1.75rem, 3.6vw, 2.5rem);
  line-height: 1.15;
  letter-spacing: -0.01em;
  color: var(--j-text);
  display: flex;
  align-items: baseline;
  gap: 14px;
  margin: 0;
}

.page-about .section-title::before {
  content: attr(data-index);
  font-family: var(--j-font-mono);
  font-size: 0.6em;
  color: var(--j-orange);
  font-weight: 700;
  line-height: 1;
}

/* ---- 品牌叙事 ---- */
.page-about .about-narrative-grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: var(--space-lg);
  align-items: start;
}

.page-about .about-lead {
  font-size: clamp(1.1rem, 1.8vw, 1.3rem);
  line-height: 1.7;
  font-weight: 600;
  color: var(--j-text);
  border-left: 3px solid var(--j-orange);
  padding-left: 16px;
  margin: 0 0 var(--space-md);
}

.page-about .about-narrative-content p {
  color: var(--j-muted);
  line-height: 1.85;
  margin: 0 0 18px;
  font-size: 0.95rem;
}

.page-about .about-narrative-content a {
  color: var(--j-blue);
  text-decoration: none;
  border-bottom: 1px solid rgba(10, 110, 189, 0.45);
  transition: color 0.2s ease, border-color 0.2s ease;
}

.page-about .about-narrative-content a:hover {
  color: var(--j-text);
  border-color: var(--j-text);
}

.page-about .about-narrative-media {
  margin: 0;
  border: 1px solid var(--j-border);
  background: var(--j-card);
  padding: 8px;
  display: flex;
  flex-direction: column;
  gap: 8px;
}

.page-about .about-narrative-media img {
  width: 100%;
  height: auto;
  display: block;
}

.page-about .about-narrative-media figcaption {
  font-family: var(--j-font-mono);
  font-size: 12px;
  color: var(--j-muted);
  padding: 0 4px 4px;
  letter-spacing: 0.04em;
}

/* ---- 发展历程时间线 ---- */
.page-about .about-timeline-layout {
  display: grid;
  grid-template-columns: 1fr;
  gap: var(--space-lg);
  align-items: start;
}

.page-about .about-timeline {
  position: relative;
  padding-left: var(--about-tl-gutter);
}

.page-about .about-timeline::before {
  content: "";
  position: absolute;
  left: 7px;
  top: 10px;
  bottom: 10px;
  width: 2px;
  background: linear-gradient(180deg, var(--j-blue) 0%, var(--j-orange) 100%);
}

.page-about .about-tl-item {
  position: relative;
  margin-bottom: var(--space-md);
  background: var(--about-card-alpha);
  border: 1px solid var(--j-border);
  transition: border-color 0.25s ease;
}

.page-about .about-tl-item[open] {
  border-color: rgba(10, 110, 189, 0.6);
}

.page-about .about-tl-summary {
  position: relative;
  list-style: none;
  cursor: pointer;
  user-select: none;
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 10px 14px;
  padding: 18px 20px 18px 22px;
}

.page-about .about-tl-summary::-webkit-details-marker {
  display: none;
}

.page-about .about-tl-summary::before {
  content: "";
  position: absolute;
  left: calc(-1 * var(--about-tl-gutter) + 1px);
  top: 50%;
  width: var(--about-diamond);
  height: var(--about-diamond);
  margin-top: calc(var(--about-diamond) / -2);
  background: var(--j-card);
  border: 2px solid var(--j-blue);
  transform: rotate(45deg);
  transition: background 0.25s ease, border-color 0.25s ease;
}

.page-about .about-tl-item[open] .about-tl-summary::before {
  background: var(--j-orange);
  border-color: var(--j-orange);
}

.page-about .about-tl-year {
  font-family: var(--j-font-mono);
  font-size: 1.5rem;
  font-weight: 700;
  color: var(--j-blue);
  min-width: 56px;
  letter-spacing: -0.02em;
  line-height: 1.1;
}

.page-about .about-tl-heading {
  font-family: var(--j-font-display);
  font-size: 1rem;
  color: var(--j-text);
  flex: 1;
  letter-spacing: 0.01em;
}

.page-about .about-tl-tag {
  font-family: var(--j-font-mono);
  font-size: 12px;
  letter-spacing: 0.08em;
}

.page-about .about-tl-body {
  padding: 0 20px 18px 22px;
  border-top: 1px solid var(--j-border);
  font-size: 14px;
  line-height: 1.8;
  color: var(--j-muted);
  background: rgba(18, 22, 28, 0.5);
}

.page-about .about-tl-body p {
  margin: 14px 0 0;
}

.page-about .about-timeline-media {
  margin: 0;
  border: 1px solid var(--j-border);
  background: var(--j-card);
  padding: 8px;
  display: flex;
  flex-direction: column;
  gap: 8px;
}

.page-about .about-timeline-media img {
  width: 100%;
  height: auto;
  display: block;
}

.page-about .about-timeline-media figcaption {
  font-family: var(--j-font-mono);
  font-size: 12px;
  color: var(--j-muted);
  padding: 0 4px 4px;
}

/* ---- 服务能力 ---- */
.page-about .about-capabilities-intro {
  max-width: 720px;
  color: var(--j-muted);
  font-size: 0.95rem;
  line-height: 1.8;
  margin-bottom: var(--space-lg);
}

.page-about .about-capabilities-intro p {
  margin: 0;
}

.page-about .about-capabilities-layout {
  display: grid;
  grid-template-columns: 1fr;
  gap: var(--space-lg);
  align-items: center;
}

.page-about .about-stats-grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: 12px;
}

.page-about .about-stat-card {
  padding: 20px 20px;
  background: var(--j-card);
  border: 1px solid var(--j-border);
  display: flex;
  flex-direction: column;
  gap: 8px;
  transition: border-color 0.25s ease;
}

.page-about .about-stat-card:hover {
  border-color: rgba(10, 110, 189, 0.6);
}

.page-about .about-stat-num {
  font-family: var(--j-font-mono);
  font-size: clamp(2rem, 5vw, 2.9rem);
  font-weight: 700;
  color: var(--j-orange);
  line-height: 1.1;
  letter-spacing: -0.03em;
}

.page-about .about-stat-label {
  font-size: 13px;
  color: var(--j-muted);
  letter-spacing: 0.03em;
  line-height: 1.5;
}

.page-about .about-capability-media {
  margin: 0;
  border: 1px solid var(--j-border);
  background: var(--j-card);
  padding: 8px;
  display: flex;
  flex-direction: column;
  gap: 8px;
}

.page-about .about-capability-media img {
  width: 100%;
  height: auto;
  display: block;
}

.page-about .about-capability-media figcaption {
  font-family: var(--j-font-mono);
  font-size: 12px;
  color: var(--j-muted);
  padding: 0 4px 4px;
}

/* ---- 资质与备案 ---- */
.page-about .about-credential-grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: 14px;
}

.page-about .about-credential-card {
  background: var(--j-card);
  border: 1px solid var(--j-border);
  padding: 24px;
  display: flex;
  flex-direction: column;
  gap: 12px;
}

.page-about .about-credential-card h3 {
  font-family: var(--j-font-display);
  font-size: 1.05rem;
  color: var(--j-text);
  margin: 0;
  padding-bottom: 10px;
  border-bottom: 2px solid var(--j-blue);
  position: relative;
}

.page-about .about-credential-card h3::after {
  content: "";
  position: absolute;
  left: 0;
  bottom: -2px;
  width: 36px;
  height: 2px;
  background: var(--j-orange);
}

.page-about .about-credential-card p {
  color: var(--j-muted);
  font-size: 0.9rem;
  line-height: 1.8;
  margin: 0;
}

.page-about .about-credential-note {
  margin-top: var(--space-lg);
  border: 1px dashed var(--j-border);
  background: rgba(10, 110, 189, 0.06);
  padding: 16px 20px;
}

.page-about .about-credential-note p {
  margin: 0;
  color: var(--j-muted);
  font-size: 13px;
  line-height: 1.8;
}

.page-about .about-credential-note a {
  color: var(--j-blue);
  text-decoration: none;
  border-bottom: 1px solid rgba(10, 110, 189, 0.45);
  transition: color 0.2s ease, border-color 0.2s ease;
}

.page-about .about-credential-note a:hover {
  color: var(--j-text);
  border-color: var(--j-text);
}

/* ---- 继续了解 ---- */
.page-about .about-next {
  display: grid;
  grid-template-columns: 1fr;
  gap: 14px;
  padding: var(--space-lg) 0 var(--space-xl);
  border-top: 1px solid var(--j-border);
  margin-top: var(--space-md);
}

.page-about .about-next-card {
  text-decoration: none;
  background: var(--j-card);
  border: 1px solid var(--j-border);
  border-left: 3px solid var(--j-blue);
  padding: 18px 20px;
  display: flex;
  flex-direction: column;
  gap: 6px;
  transition: border-color 0.25s ease, transform 0.25s ease, background-color 0.25s ease;
}

.page-about .about-next-card:hover {
  border-left-color: var(--j-orange);
  background-color: rgba(10, 110, 189, 0.08);
  transform: translateX(4px);
}

.page-about .about-next-code {
  font-family: var(--j-font-mono);
  font-size: 12px;
  color: var(--j-orange);
  letter-spacing: 0.12em;
}

.page-about .about-next-title {
  font-family: var(--j-font-display);
  font-size: 16px;
  color: var(--j-text);
}

.page-about .about-next-desc {
  font-size: 13px;
  color: var(--j-muted);
  line-height: 1.6;
}

/* ---- 响应式 ---- */
@media (min-width: 560px) {
  .page-about .container {
    padding: 0 var(--space-lg);
  }

  .page-about .about-index {
    grid-template-columns: repeat(2, 1fr);
  }

  .page-about .about-stats-grid {
    grid-template-columns: repeat(2, 1fr);
  }
}

@media (min-width: 900px) {
  .page-about .about-index {
    grid-template-columns: repeat(4, 1fr);
  }

  .page-about .section {
    padding: clamp(56px, 7vw, 88px) 0;
  }

  .page-about .about-narrative-grid {
    grid-template-columns: 1.1fr 0.9fr;
    gap: var(--space-xl);
  }

  .page-about .about-timeline-layout {
    grid-template-columns: 1.35fr 0.65fr;
    gap: var(--space-xl);
  }

  .page-about .about-capabilities-layout {
    grid-template-columns: 1.1fr 0.9fr;
    gap: var(--space-xl);
  }

  .page-about .about-stats-grid {
    grid-template-columns: repeat(3, 1fr);
    gap: 14px;
  }

  .page-about .about-credential-grid {
    grid-template-columns: repeat(3, 1fr);
    gap: 18px;
  }

  .page-about .about-next {
    grid-template-columns: repeat(3, 1fr);
    gap: 18px;
  }
}