/* ========== 品牌概况页专属样式 page-about ========== */
.page-about {
  --page-about-bg-start: #0A1628;
  --page-about-bg-end: #1A2A40;
  --page-about-card-bg: #1A2A40;
  --page-about-border-color: #C0C0C0;
  --page-about-paper-shadow: 0 8px 32px rgba(0,0,0,0.4);
  --page-about-timeline-line: #C0C0C0;
  --page-about-gap: 2rem;
  --page-about-radius: 0;
  background: linear-gradient(135deg, var(--page-about-bg-start), var(--page-about-bg-end));
  padding-top: calc(var(--header-height) + 2rem);
  padding-bottom: 4rem;
  min-height: 100vh;
}

/* ===== 面包屑 ===== */
.page-about__breadcrumb {
  margin-bottom: 2.5rem;
  padding: 0.5rem 0;
}

/* ===== 首屏区 ===== */
.page-about__hero {
  margin-bottom: 4rem;
}

.page-about__hero-content {
  display: grid;
  grid-template-columns: 1fr;
  gap: var(--page-about-gap);
  align-items: center;
}

.page-about__hero-text {
  order: 2;
}

.page-about__hero-image {
  order: 1;
  position: relative;
}

.page-about__hero-title {
  font-family: var(--font-heading);
  font-size: 2.8rem;
  font-weight: 900;
  line-height: 1.1;
  color: var(--color-white);
  margin: 0 0 0.5rem;
  letter-spacing: -0.02em;
}

.page-about__hero-subtitle {
  font-family: var(--font-heading);
  font-size: 1.4rem;
  font-weight: 600;
  color: var(--color-primary);
  margin: 0 0 1rem;
}

.page-about__hero-desc {
  font-family: var(--font-body);
  font-size: 1.05rem;
  line-height: 1.7;
  color: var(--color-text-secondary);
  margin: 0 0 2rem;
  max-width: 540px;
}

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

.page-about__cta {
  font-family: var(--font-body);
  font-weight: 600;
  text-decoration: none;
}

.page-about__img {
  display: block;
  width: 100%;
  max-width: 100%;
  height: auto;
  object-fit: cover;
  border: 1px solid var(--page-about-border-color);
  box-shadow: var(--page-about-paper-shadow);
  filter: saturate(0.85) contrast(1.1);
}

/* ===== 使命卡片（纸张叠层） ===== */
.page-about__vision {
  margin-bottom: 4rem;
}

.page-about__vision-card {
  background: var(--page-about-card-bg);
  border: 1px solid var(--page-about-border-color);
  padding: 2.5rem 2rem;
  position: relative;
  box-shadow: var(--page-about-paper-shadow);
  transform: rotate(-0.3deg);
}

.page-about__vision-card::before {
  content: '';
  position: absolute;
  top: -4px;
  left: -4px;
  right: -4px;
  bottom: -4px;
  border: 1px solid var(--page-about-border-color);
  pointer-events: none;
  z-index: 1;
}

.page-about__vision-tag {
  margin-bottom: 1rem;
  display: inline-block;
}

.page-about__vision-card p {
  font-family: var(--font-body);
  font-size: 1rem;
  line-height: 1.8;
  color: #E0E0E0;
  margin: 0;
}

/* ===== 核心功能 ===== */
.page-about__functions {
  margin-bottom: 4rem;
}

.page-about__functions-title {
  margin-bottom: 2rem;
}

.page-about__functions-grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: 2rem;
}

.page-about__function-card {
  background: var(--page-about-card-bg);
  border: 1px solid var(--page-about-border-color);
  padding: 2rem;
  display: flex;
  flex-direction: column;
  transition: transform 0.25s ease, box-shadow 0.25s ease;
}

.page-about__function-card:hover {
  transform: translateY(-4px);
  box-shadow: 0 12px 40px rgba(0,0,0,0.5);
}

.page-about__function-icon {
  margin-bottom: 1rem;
}

.page-about__function-name {
  font-family: var(--font-heading);
  font-size: 1.4rem;
  font-weight: 700;
  color: var(--color-white);
  margin: 0 0 0.75rem;
}

.page-about__function-desc {
  font-family: var(--font-body);
  font-size: 0.95rem;
  line-height: 1.7;
  color: var(--color-text-secondary);
  margin: 0 0 1.5rem;
  flex-grow: 1;
}

.page-about__function-image {
  margin-top: auto;
}

.page-about__function-image .page-about__img {
  border-color: var(--color-silver);
}

/* ===== 时间轴 ===== */
.page-about__timeline {
  margin-bottom: 4rem;
}

.page-about__timeline-title {
  margin-bottom: 0.5rem;
}

.page-about__timeline-desc {
  font-family: var(--font-body);
  font-size: 1rem;
  color: var(--color-text-secondary);
  margin: 0 0 2.5rem;
}

.page-about__timeline-list {
  position: relative;
  padding-left: 0;
}

/* 时间轴线 */
.page-about__timeline-list::before {
  content: '';
  position: absolute;
  left: 30px;
  top: 0;
  bottom: 0;
  width: 2px;
  background: var(--page-about-timeline-line);
  opacity: 0.3;
}

.page-about__timeline-item {
  display: flex;
  gap: 1.5rem;
  margin-bottom: 2.5rem;
  position: relative;
}

.page-about__timeline-marker {
  display: flex;
  flex-direction: column;
  align-items: center;
  flex-shrink: 0;
  width: 60px;
  position: relative;
  z-index: 2;
}

.page-about__timeline-icon {
  display: block;
  width: 60px;
  height: 60px;
  object-fit: cover;
  border: 1px solid var(--page-about-border-color);
  background: var(--page-about-bg-start);
}

.page-about__timeline-date {
  font-family: var(--font-heading);
  font-size: 0.75rem;
  font-weight: 600;
  color: var(--color-primary);
  letter-spacing: 0.05em;
  margin-top: 0.5rem;
  white-space: nowrap;
}

.page-about__timeline-content {
  flex: 1;
  padding-bottom: 1rem;
  border-bottom: 1px solid rgba(192,192,192,0.15);
}

.page-about__timeline-heading {
  font-family: var(--font-heading);
  font-size: 1.2rem;
  font-weight: 700;
  color: var(--color-white);
  margin: 0 0 0.5rem;
}

.page-about__timeline-content p {
  font-family: var(--font-body);
  font-size: 0.95rem;
  line-height: 1.7;
  color: var(--color-text-secondary);
  margin: 0 0 0.75rem;
}

.page-about__timeline-btn {
  font-size: 0.85rem !important;
  padding: 0.3rem 1rem !important;
}

.page-about__timeline-btn[aria-expanded="true"] {
  background: var(--color-primary);
  color: var(--color-white);
  border-color: var(--color-primary);
}

.page-about__timeline-detail {
  margin-top: 0.75rem;
  padding: 1rem;
  background: rgba(0,0,0,0.2);
  border-left: 3px solid var(--color-primary);
}

.page-about__timeline-detail p {
  margin: 0;
}

/* ===== 信任声明 ===== */
.page-about__trust {
  margin-bottom: 0;
}

.page-about__trust-box {
  border: 2px solid var(--page-about-border-color);
  padding: 2rem;
  text-align: center;
  background: var(--page-about-card-bg);
}

.page-about__trust-tag {
  display: inline-block;
  margin-bottom: 1rem;
}

.page-about__trust-text {
  font-family: var(--font-body);
  font-size: 1.1rem;
  color: var(--color-white);
  margin: 0 0 1rem;
  font-weight: 500;
}

.page-about__trust-link {
  font-family: var(--font-body);
  font-size: 0.95rem;
  color: var(--color-primary);
  text-decoration: none;
  border-bottom: 1px solid transparent;
  transition: border-color 0.2s;
}

.page-about__trust-link:hover {
  border-bottom-color: var(--color-primary);
}

/* ===== 通用 ===== */
.page-about__section-title {
  font-family: var(--font-heading);
  font-size: 2rem;
  font-weight: 800;
  color: var(--color-white);
  margin: 0 0 1.5rem;
  letter-spacing: -0.01em;
  position: relative;
  display: inline-block;
}

.page-about__section-title::after {
  content: '';
  display: block;
  width: 60px;
  height: 4px;
  background: var(--color-primary);
  margin-top: 0.5rem;
}

/* ===== 滚动显现动画 ===== */
.page-about .reveal {
  opacity: 0;
  transform: translateY(30px);
  transition: opacity 0.5s ease, transform 0.5s ease;
}

.page-about .reveal--visible {
  opacity: 1;
  transform: translateY(0);
}

/* ===== 响应式 ===== */
@media (prefers-reduced-motion: reduce) {
  .page-about .reveal {
    opacity: 1;
    transform: none;
  }
  .page-about__function-card:hover {
    transform: none;
  }
}

@media (min-width: 768px) {
  .page-about {
    padding-top: calc(var(--header-height) + 3.5rem);
  }
  .page-about__hero-content {
    grid-template-columns: 1fr 1fr;
  }
  .page-about__hero-text {
    order: 1;
  }
  .page-about__hero-image {
    order: 2;
  }
  .page-about__hero-title {
    font-size: 3.8rem;
  }
  .page-about__hero-subtitle {
    font-size: 1.6rem;
  }
  .page-about__functions-grid {
    grid-template-columns: repeat(3, 1fr);
  }
  .page-about__timeline-list::before {
    left: 30px;
  }
  .page-about__timeline-item {
    padding-left: 0;
  }
  .page-about__vision-card {
    padding: 3.5rem 3rem;
  }
  .page-about__section-title {
    font-size: 2.4rem;
  }
}

@media (min-width: 1024px) {
  .page-about__hero-title {
    font-size: 4.2rem;
  }
  .page-about__section-title {
    font-size: 2.8rem;
  }
}

/* 超过容器宽度时的图像保障 */
.page-about img {
  max-width: 100%;
  height: auto;
}