.page-about {
  --about-gradient-lake: linear-gradient(135deg, #1B6CA8 0%, #0B3A5C 100%);
  --about-plane: #F8F9FA;
  --about-line: #C5D3E0;
  --about-ink: #172B3A;

  background: var(--about-plane);
  color: var(--about-ink);
  font-family: var(--body-font);
  overflow-x: hidden;
}

.page-about .breadcrumbs {
  max-width: var(--maxw);
  margin: 0 auto;
  padding: 1.25rem 1rem 0;
  font-size: 0.875rem;
  color: var(--ink-soft);
}

.page-about .breadcrumbs a {
  color: var(--primary-lake);
  text-decoration: none;
  border-bottom: 1px solid transparent;
  transition: border-color var(--ease);
}

.page-about .breadcrumbs a:hover {
  border-bottom-color: var(--primary-lake);
}

.page-about .sep {
  margin: 0 0.5rem;
  color: var(--line-ice);
}

.page-about .page-header {
  max-width: var(--maxw);
  margin: 0 auto;
  padding: 2.5rem 1rem 1.5rem;
}

.page-about .page-kicker {
  font-family: var(--display-font);
  font-size: 1rem;
  letter-spacing: 0.18em;
  text-transform: uppercase;
  color: var(--sunset-orange);
  margin-bottom: 0.5rem;
}

.page-about .page-title {
  font-family: var(--display-font);
  font-size: clamp(2.5rem, 7vw, 5rem);
  font-weight: 700;
  line-height: 0.98;
  margin: 0 0 1rem;
  max-width: 14em;
}

.page-about .page-lead {
  font-size: 1.125rem;
  line-height: 1.7;
  max-width: 36em;
  color: var(--ink-soft);
  margin: 0;
}

/* ===== 首屏品牌区 ===== */
.page-about .about-hero {
  max-width: var(--maxw);
  margin: 0 auto;
  padding: 2rem 1rem 3.5rem;
  display: grid;
  grid-template-columns: 1fr;
  gap: 2rem;
  align-items: center;
}

@media (min-width: 760px) {
  .page-about .about-hero {
    grid-template-columns: 1fr 1fr;
    padding: 3rem 1rem 5rem;
  }
}

.page-about .about-hero-copy {
  background: var(--about-gradient-lake);
  color: #fff;
  border-radius: 0;
  padding: 2rem 1.75rem;
  min-height: 280px;
  display: flex;
  flex-direction: column;
  justify-content: center;
  gap: 1rem;
}

.page-about .about-hero-copy p {
  font-size: 1rem;
  line-height: 1.8;
  margin: 0;
  max-width: 30em;
}

.page-about .about-hero-image {
  margin: 0;
}

.page-about .about-hero-image img {
  width: 100%;
  height: auto;
  display: block;
  object-fit: cover;
}

/* ===== 章节通用 ===== */
.page-about .section {
  max-width: var(--maxw);
  margin: 0 auto;
  padding: 3rem 1rem;
}

.page-about .section-head {
  display: flex;
  align-items: baseline;
  gap: 1rem;
  border-bottom: 2px solid var(--about-ink);
  padding-bottom: 0.75rem;
  margin-bottom: 2rem;
}

.page-about .section-index {
  font-family: var(--display-font);
  font-size: 2.75rem;
  font-weight: 700;
  line-height: 1;
  color: var(--primary-lake);
}

.page-about .section-title {
  font-family: var(--display-font);
  font-size: clamp(1.75rem, 4vw, 2.5rem);
  font-weight: 600;
  line-height: 1;
  margin: 0;
}

/* ===== 01 品牌使命 ===== */
.page-about .about-mission-grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: 2.5rem;
}

@media (min-width: 821px) {
  .page-about .about-mission-grid {
    grid-template-columns: 2fr 1fr;
    gap: 3rem;
  }
}

.page-about .about-mission-text p {
  font-size: 1rem;
  line-height: 1.8;
  color: var(--ink-blue);
  margin-bottom: 1rem;
  max-width: 42em;
}

.page-about .about-mission-aside {
  background: var(--cloud-gray);
  padding: 1.75rem 1.5rem;
  border-left: 4px solid var(--primary-lake);
}

.page-about .aside-label {
  font-family: var(--display-font);
  font-size: 1rem;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  color: var(--ink-soft);
  margin-bottom: 1rem;
}

.page-about .about-tag-list {
  list-style: none;
  margin: 0;
  padding: 0;
  display: flex;
  flex-wrap: wrap;
  gap: 0.5rem;
}

.page-about .about-tag-list li {
  background: #fff;
  border: 1px solid var(--line-ice);
  padding: 0.4rem 0.85rem;
  font-size: 0.85rem;
  font-weight: 600;
  color: var(--primary-lake);
  letter-spacing: 0.02em;
}

/* ===== 02 时间线 ===== */
.page-about .timeline-wrap {
  position: relative;
  display: grid;
  grid-template-columns: 1fr;
  gap: 2rem;
}

@media (min-width: 900px) {
  .page-about .timeline-wrap {
    grid-template-columns: 0.45fr 1fr;
    gap: 3rem;
    align-items: start;
  }
}

.page-about .timeline-bg {
  display: none;
  margin: 0;
}

@media (min-width: 900px) {
  .page-about .timeline-bg {
    display: block;
    margin-top: 1rem;
  }
}

.page-about .timeline-bg img {
  width: 100%;
  height: auto;
  object-fit: cover;
  display: block;
  border: 1px solid var(--about-line);
}

.page-about .timeline-list {
  list-style: none;
  margin: 0;
  padding: 0;
  position: relative;
}

.page-about .timeline-list::before {
  content: "";
  position: absolute;
  left: 7px;
  top: 0;
  bottom: 0;
  width: 2px;
  background: var(--line-ice);
}

.page-about .timeline-item {
  position: relative;
  padding-left: 2.5rem;
  padding-bottom: 2.5rem;
}

.page-about .timeline-item:last-child {
  padding-bottom: 0;
}

.page-about .timeline-node {
  position: absolute;
  left: 0;
  top: 0.4rem;
  width: 16px;
  height: 16px;
  border-radius: 50%;
  background: var(--primary-lake);
  border: 3px solid #fff;
  box-shadow: 0 0 0 2px var(--primary-lake);
}

.page-about .timeline-card {
  background: #fff;
  border: 1px solid var(--about-line);
  border-left: 3px solid var(--primary-lake);
  padding: 1.25rem 1.5rem;
  transition: transform var(--ease), box-shadow var(--ease);
}

.page-about .timeline-card:hover {
  transform: translateY(-5px);
  box-shadow: 0 8px 24px rgba(11, 58, 92, 0.08);
}

.page-about .timeline-version {
  display: inline-block;
  font-family: var(--display-font);
  font-size: 1.5rem;
  font-weight: 700;
  color: var(--sunset-orange);
  letter-spacing: 0.04em;
  margin-bottom: 0.4rem;
}

.page-about .timeline-card h3 {
  font-size: 1.1rem;
  font-weight: 700;
  margin: 0 0 0.5rem;
  color: var(--ink-blue);
}

.page-about .timeline-card p {
  font-size: 0.925rem;
  line-height: 1.65;
  margin: 0;
  color: var(--ink-soft);
}

/* ===== 03 数据能力 ===== */
.page-about .capability-intro {
  max-width: 42em;
  font-size: 1.05rem;
  line-height: 1.7;
  color: var(--ink-soft);
  margin-bottom: 2rem;
}

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

@media (min-width: 560px) {
  .page-about .capability-grid {
    grid-template-columns: repeat(2, 1fr);
  }
}

@media (min-width: 960px) {
  .page-about .capability-grid {
    grid-template-columns: repeat(3, 1fr);
  }
}

.page-about .capability-card {
  border: 1px solid var(--about-line);
  border-radius: 0;
  padding: 1.75rem 1.5rem;
  transition: transform var(--ease), box-shadow var(--ease);
}

.page-about .capability-card:hover {
  transform: translateY(-5px);
  box-shadow: 0 8px 24px rgba(11, 58, 92, 0.08);
}

.page-about .capability-num {
  font-family: var(--display-font);
  font-size: 2.5rem;
  font-weight: 700;
  line-height: 1;
  color: var(--primary-lake);
  margin: 0 0 0.75rem;
}

.page-about .capability-card h3 {
  font-size: 1rem;
  font-weight: 700;
  margin: 0 0 0.5rem;
  color: var(--ink-blue);
}

.page-about .capability-card p {
  font-size: 0.925rem;
  line-height: 1.6;
  color: var(--ink-soft);
  margin: 0;
}

.page-about .capability-visual {
  margin-top: 3rem;
  display: grid;
  grid-template-columns: 1fr;
  gap: 1.5rem;
  align-items: center;
}

@media (min-width: 820px) {
  .page-about .capability-visual {
    grid-template-columns: 1.2fr 0.8fr;
  }
}

.page-about .capability-visual .image-frame {
  margin: 0;
}

.page-about .capability-visual img {
  width: 100%;
  height: auto;
  display: block;
  object-fit: cover;
}

.page-about .capability-note {
  background: var(--about-gradient-lake);
  color: #fff;
  padding: 2rem 1.75rem;
  min-height: 220px;
  display: flex;
  flex-direction: column;
  justify-content: center;
}

.page-about .note-title {
  font-family: var(--display-font);
  font-size: 1.5rem;
  font-weight: 700;
  margin: 0 0 0.75rem;
}

.page-about .capability-note p {
  font-size: 0.95rem;
  line-height: 1.7;
  margin: 0;
}

/* ===== 04 V4 亮点 ===== */
.page-about .v4-display {
  display: grid;
  grid-template-columns: 1fr;
  gap: 2rem;
}

@media (min-width: 900px) {
  .page-about .v4-display {
    grid-template-columns: 0.35fr 1fr;
    gap: 3rem;
    align-items: start;
  }
}

.page-about .v4-version {
  font-family: var(--display-font);
  font-size: clamp(5rem, 14vw, 9rem);
  font-weight: 700;
  line-height: 0.9;
  color: var(--line-ice);
  transform: rotate(-6deg);
  transform-origin: left center;
  user-select: none;
  letter-spacing: -0.02em;
}

@media (min-width: 900px) {
  .page-about .v4-version {
    position: sticky;
    top: 5rem;
    font-size: 8rem;
  }
}

.page-about .v4-point-list {
  list-style: none;
  margin: 0;
  padding: 0;
  border-top: 2px solid var(--about-ink);
}

.page-about .v4-point-list li {
  display: grid;
  grid-template-columns: 3rem 1fr;
  gap: 1.25rem;
  padding: 1.5rem 0;
  border-bottom: 1px solid var(--line-ice);
  align-items: start;
}

.page-about .v4-point-index {
  font-family: var(--display-font);
  font-size: 1.5rem;
  font-weight: 700;
  color: var(--sunset-orange);
}

.page-about .v4-point-list h3 {
  font-size: 1.1rem;
  font-weight: 700;
  color: var(--ink-blue);
  margin: 0 0 0.5rem;
}

.page-about .v4-point-list p {
  font-size: 0.95rem;
  line-height: 1.65;
  color: var(--ink-soft);
  margin: 0;
  max-width: 36em;
}

/* ===== 05 服务承诺 ===== */
.page-about .commitment-grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: 1rem;
}

@media (min-width: 760px) {
  .page-about .commitment-grid {
    grid-template-columns: repeat(3, 1fr);
  }
}

.page-about .commitment-block {
  background: var(--cloud-gray);
  padding: 2rem 1.75rem;
  border-top: 4px solid var(--primary-lake);
}

.page-about .commitment-num {
  font-family: var(--display-font);
  font-size: 2.25rem;
  font-weight: 700;
  color: var(--primary-lake);
  margin: 0 0 0.75rem;
}

.page-about .commitment-block h3 {
  font-size: 1rem;
  font-weight: 700;
  color: var(--ink-blue);
  margin: 0 0 0.5rem;
}

.page-about .commitment-block p {
  font-size: 0.925rem;
  line-height: 1.6;
  color: var(--ink-soft);
  margin: 0;
}

.page-about .commitment-actions {
  display: flex;
  flex-wrap: wrap;
  gap: 0.75rem;
  margin-top: 2rem;
}

.page-about .btn {
  display: inline-block;
  font-family: var(--body-font);
  font-size: 0.9rem;
  font-weight: 600;
  padding: 0.7rem 1.5rem;
  text-decoration: none;
  border-radius: 0;
  transition: background var(--ease), color var(--ease), transform var(--ease);
}

.page-about .btn-primary {
  background: var(--primary-lake);
  color: #fff;
  border: 2px solid var(--primary-lake);
}

.page-about .btn-primary:hover {
  background: var(--lake-deep);
  border-color: var(--lake-deep);
  transform: translateY(-2px);
}

.page-about .btn-ghost {
  background: transparent;
  color: var(--primary-lake);
  border: 2px solid var(--primary-lake);
}

.page-about .btn-ghost:hover {
  background: var(--primary-lake);
  color: #fff;
  transform: translateY(-2px);
}

/* ===== 06 更多入口 ===== */
.page-about .more-link-grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: 1rem;
}

@media (min-width: 760px) {
  .page-about .more-link-grid {
    grid-template-columns: repeat(2, 1fr);
  }
}

.page-about .more-link {
  display: block;
  background: #fff;
  border: 1px solid var(--line-ice);
  padding: 1.5rem 1.75rem;
  font-size: 1rem;
  font-weight: 600;
  color: var(--ink-blue);
  text-decoration: none;
  transition: border-color var(--ease), color var(--ease), transform var(--ease);
}

.page-about .more-link:hover {
  border-color: var(--primary-lake);
  color: var(--primary-lake);
  transform: translateY(-4px);
}

@media (prefers-reduced-motion: reduce) {
  .page-about *,
  .page-about *::before,
  .page-about *::after {
    transition: none !important;
    animation: none !important;
  }
}