/* 品牌档案页面专属样式 */
.page-about {
  /* 定义页面级变量（不覆盖全局） */
  --page-about-hero-min-height: 60vh;
  --page-about-card-hover-translate: -6px;
  --page-about-timeline-line-color: var(--color-accent-blue, #00D4FF);
  --page-about-timeline-marker-size: 16px;
  --page-about-badge-bg: var(--color-accent-orange, #FF6B35);
  --page-about-badge-color: #fff;
}

/* 面包屑：继承全局 .breadcrumb 即可，此处仅微调 */
.page-about .breadcrumb {
  margin-bottom: 1rem;
  padding-left: 0;
}
@media (max-width: 767px) {
  .page-about .breadcrumb {
    font-size: 0.875rem;
  }
}

/* ---------- 首屏宽幅品牌声明 ---------- */
.page-about__hero {
  position: relative;
  min-height: var(--page-about-hero-min-height);
  display: flex;
  align-items: center;
  justify-content: center;
  overflow: hidden;
  background: var(--color-secondary-bg, #1A2D4A);
  margin-bottom: 3rem;
}

.page-about__hero-bg {
  position: absolute;
  inset: 0;
  opacity: 0.25;
  z-index: 0;
}
.page-about__hero-img {
  width: 100%;
  height: 100%;
  object-fit: cover;
  object-position: center;
}

.page-about__hero-content {
  position: relative;
  z-index: 1;
  max-width: 800px;
  text-align: center;
  padding: 3rem 1.5rem;
  color: var(--color-text-primary, #fff);
}

.page-about__hero-badge {
  display: inline-block;
  background: var(--page-about-badge-bg);
  color: var(--page-about-badge-color);
  font-family: var(--font-heading, 'Arial Black', sans-serif);
  font-size: 0.875rem;
  letter-spacing: 0.1em;
  padding: 0.5rem 1.2rem;
  border-radius: 4px;
  margin-bottom: 1.5rem;
  text-transform: uppercase;
}

.page-about__hero-title {
  font-family: var(--font-heading, 'Arial Black', sans-serif);
  font-size: var(--h1-size, 3rem);
  line-height: 1.1;
  margin-bottom: 1rem;
  color: var(--color-text-primary, #fff);
  text-shadow: 0 2px 8px rgba(0,0,0,0.4);
}

.page-about__hero-sub {
  font-family: var(--font-body, system-ui, sans-serif);
  font-size: var(--body-size, 1rem);
  line-height: 1.6;
  color: var(--color-text-secondary, #B0B0B8);
  margin-bottom: 2rem;
  max-width: 600px;
  margin-left: auto;
  margin-right: auto;
}

/* ---------- 通用章节标题 ---------- */
.page-about__section-title {
  font-family: var(--font-heading, 'Arial Black', sans-serif);
  font-size: var(--h2-size, 2.25rem);
  margin-bottom: 2rem;
  color: var(--color-accent-blue, #00D4FF);
  border-bottom: 2px solid var(--color-border, #2A3F5A);
  padding-bottom: 0.5rem;
}

/* ---------- 第二节：核心功能卡片 ---------- */
.page-about__features {
  margin-bottom: 4rem;
}

.page-about__features-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
  gap: 1.5rem;
}

.page-about__feature-card {
  background: var(--color-card-bg, #14283F);
  border: 1px solid var(--color-border, #2A3F5A);
  border-radius: 8px;
  transition: transform var(--transition-base, 0.3s ease), box-shadow var(--transition-base, 0.3s ease);
  cursor: default;
}
.page-about__feature-card:hover,
.page-about__feature-card:focus-within {
  transform: translateY(var(--page-about-card-hover-translate));
  box-shadow: 0 8px 24px rgba(0, 212, 255, 0.1);
}
.page-about__feature-card .card-header {
  display: flex;
  align-items: center;
  gap: 0.75rem;
  padding: 1.25rem 1.25rem 0;
}
.page-about__feature-icon {
  font-size: 1.8rem;
  line-height: 1;
}
.page-about__feature-card h3 {
  font-family: var(--font-heading, 'Arial Black', sans-serif);
  font-size: var(--h3-size, 1.5rem);
  margin: 0;
}
.page-about__feature-card .card-body {
  padding: 1rem 1.25rem 1.25rem;
  color: var(--color-text-secondary, #B0B0B8);
  font-family: var(--font-body, system-ui, sans-serif);
  font-size: var(--body-size, 1rem);
  line-height: 1.6;
}
.page-about__version-tag {
  display: inline-block;
  background: var(--color-accent-blue, #00D4FF);
  color: var(--color-primary-bg, #0B1D3A);
  font-family: var(--font-digit, 'Courier New', monospace);
  font-size: 0.8rem;
  padding: 0.2rem 0.6rem;
  border-radius: 3px;
  margin-top: 0.5rem;
}

/* ---------- 第三节：全宽时间线 ---------- */
.page-about__timeline {
  background: var(--color-secondary-bg, #1A2D4A);
  padding: 4rem 0;
  margin-bottom: 4rem;
}

.page-about__timeline-list {
  position: relative;
  padding-left: 2rem;
}
.page-about__timeline-list::before {
  content: '';
  position: absolute;
  left: 8px;
  top: 0;
  bottom: 0;
  width: 2px;
  background: var(--page-about-timeline-line-color);
}

.page-about__timeline-item {
  position: relative;
  margin-bottom: 2.5rem;
  display: flex;
  gap: 1rem;
}

.page-about__timeline-marker {
  position: absolute;
  left: calc(-2rem + 0px); /* 负偏移到竖线位置 */
  top: 4px;
  width: var(--page-about-timeline-marker-size);
  height: var(--page-about-timeline-marker-size);
  border-radius: 50%;
  background: var(--color-accent-blue, #00D4FF);
  border: 3px solid var(--color-primary-bg, #0B1D3A);
  flex-shrink: 0;
  z-index: 1;
  transition: transform var(--transition-fast, 0.2s ease);
}
.page-about__timeline-item:hover .page-about__timeline-marker,
.page-about__timeline-item:focus-within .page-about__timeline-marker {
  transform: scale(1.25);
}

.page-about__timeline-content {
  background: var(--color-card-bg, #14283F);
  border: 1px solid var(--color-border, #2A3F5A);
  border-radius: 8px;
  padding: 1.25rem;
  flex: 1;
  cursor: pointer;
  transition: box-shadow var(--transition-base, 0.3s ease);
}
.page-about__timeline-content:hover {
  box-shadow: 0 4px 16px rgba(0, 212, 255, 0.15);
}

.page-about__timeline-date {
  display: block;
  font-family: var(--font-digit, 'Courier New', monospace);
  color: var(--color-accent-orange, #FF6B35);
  font-size: 0.875rem;
  margin-bottom: 0.25rem;
}
.page-about__timeline-content h3 {
  font-family: var(--font-heading, 'Arial Black', sans-serif);
  font-size: var(--h3-size, 1.5rem);
  margin: 0 0 0.5rem 0;
}
.page-about__timeline-content p {
  font-family: var(--font-body, system-ui, sans-serif);
  font-size: var(--body-size, 1rem);
  color: var(--color-text-secondary, #B0B0B8);
  line-height: 1.6;
}
.page-about__timeline-img {
  display: block;
  max-width: 100%;
  height: auto;
  margin-top: 1rem;
  border-radius: 4px;
}

/* ---------- 第四节：技术承诺 ---------- */
.page-about__promise {
  margin-bottom: 4rem;
}

.page-about__promise-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 2rem;
  align-items: center;
}
@media (max-width: 767px) {
  .page-about__promise-grid {
    grid-template-columns: 1fr;
  }
}

.page-about__promise-text p {
  font-family: var(--font-body, system-ui, sans-serif);
  font-size: var(--body-size, 1rem);
  line-height: 1.7;
  color: var(--color-text-secondary, #B0B0B8);
  margin-bottom: 1rem;
}

.page-about__promise-img {
  max-width: 100%;
  height: auto;
  border-radius: 8px;
  border: 1px solid var(--color-border, #2A3F5A);
}

/* ---------- 移动端优先调整 ---------- */
@media (max-width: 767px) {
  .page-about__hero-title {
    font-size: 2rem;
  }
  .page-about__timeline-list {
    padding-left: 1.5rem;
  }
  .page-about__timeline-marker {
    left: calc(-1.5rem + 0px);
  }
  .page-about__features-grid {
    grid-template-columns: 1fr;
  }
}