/* ===== 页面专属样式: .page-about ===== */
.page-about {
  --sidebar-width: 260px;
  --sidebar-bg: var(--color-bg-medium);
  --gold: var(--color-accent-gold);
  --primary: var(--color-primary);
  --neon: var(--color-accent-neon);
  display: block;
  width: 100%;
  min-height: 80vh;
  position: relative;
  background-color: var(--color-bg-dark);
  color: var(--color-text-primary);
  font-family: var(--font-body);
  line-height: 1.7;
}

/* ---- 顶部进度条 ---- */
.page-about .page-progress {
  position: fixed;
  top: var(--header-height, 60px);
  left: 0;
  width: 0%;
  height: 3px;
  background: linear-gradient(90deg, var(--gold), var(--primary));
  z-index: 100;
  transition: width 0.15s ease;
  pointer-events: none;
}

/* ---- 左右画布容器 ---- */
.page-about .about-canvas {
  display: flex;
  flex-direction: column;
  width: 100%;
  max-width: var(--content-max-width, 1200px);
  margin: 0 auto;
  position: relative;
}

/* ---- 左侧索引栏 ---- */
.page-about .canvas__sidebar {
  display: none;
  background-color: var(--sidebar-bg);
  border-right: 1px solid rgba(255, 215, 0, 0.15);
  padding: 2rem 1.5rem;
  position: relative;
  z-index: 10;
  min-height: 300px;
}

.page-about .sidebar__brand {
  margin-bottom: 2.5rem;
  display: flex;
  flex-direction: column;
  gap: 0.25rem;
}

.page-about .sidebar__brand-icon {
  font-family: var(--font-tech);
  font-size: 1.8rem;
  font-weight: 400;
  color: var(--gold);
  letter-spacing: 2px;
  line-height: 1;
}

.page-about .sidebar__brand-name {
  font-family: var(--font-heading);
  font-size: 1rem;
  font-weight: 300;
  color: var(--color-text-primary);
  letter-spacing: 3px;
  text-transform: uppercase;
}

.page-about .sidebar__tagline {
  font-family: var(--font-body);
  font-size: 0.7rem;
  font-weight: 300;
  color: var(--color-text-secondary);
  letter-spacing: 1px;
  margin-top: 0.25rem;
}

.page-about .sidebar__nav {
  display: flex;
  flex-direction: column;
  gap: 0.35rem;
  margin-bottom: 2rem;
}

.page-about .sidebar__link {
  display: flex;
  align-items: center;
  gap: 0.75rem;
  padding: 0.6rem 0.8rem;
  text-decoration: none;
  color: var(--color-text-secondary);
  font-family: var(--font-body);
  font-size: 0.85rem;
  font-weight: 300;
  border-left: 2px solid transparent;
  transition: all 0.3s ease;
  border-radius: 0 4px 4px 0;
}

.page-about .sidebar__link:hover {
  color: var(--gold);
  background-color: rgba(255, 215, 0, 0.05);
  border-left-color: var(--gold);
}

.page-about .sidebar__link.is-active {
  color: var(--gold);
  border-left-color: var(--gold);
  background-color: rgba(255, 215, 0, 0.08);
  font-weight: 400;
}

.page-about .sidebar__num {
  font-family: var(--font-tech);
  font-size: 0.75rem;
  font-weight: 400;
  color: var(--primary);
  min-width: 1.8rem;
}

.page-about .sidebar__link.is-active .sidebar__num {
  color: var(--gold);
}

.page-about .sidebar__label {
  font-size: 0.85rem;
  letter-spacing: 0.5px;
}

.page-about .sidebar__footer-meta {
  margin-top: auto;
  padding-top: 1.5rem;
  border-top: 1px solid rgba(255, 215, 0, 0.1);
  display: flex;
  align-items: center;
  gap: 0.5rem;
}

.page-about .sidebar__meta-dot {
  width: 6px;
  height: 6px;
  border-radius: 50%;
  background-color: var(--neon);
  opacity: 0.6;
}

.page-about .sidebar__meta-text {
  font-size: 0.6rem;
  font-weight: 300;
  color: var(--color-text-secondary);
  letter-spacing: 1px;
  text-transform: uppercase;
}

/* ---- 右侧主内容 ---- */
.page-about .canvas__main {
  flex: 1;
  min-width: 0;
  padding: 0 1.25rem;
  position: relative;
}

/* ---- 移动端导航（水平） ---- */
.page-about .canvas__mobile-nav {
  display: flex;
  gap: 0.25rem;
  padding: 1rem 0 0.5rem;
  overflow-x: auto;
  scrollbar-width: none;
  -ms-overflow-style: none;
  position: sticky;
  top: calc(var(--header-height, 60px) + 4px);
  z-index: 20;
  background-color: var(--color-bg-dark);
}

.page-about .canvas__mobile-nav::-webkit-scrollbar {
  display: none;
}

.page-about .mobile-nav__link {
  flex-shrink: 0;
  padding: 0.45rem 1rem;
  text-decoration: none;
  color: var(--color-text-secondary);
  font-family: var(--font-body);
  font-size: 0.78rem;
  font-weight: 300;
  border: 1px solid rgba(255, 215, 0, 0.2);
  border-radius: 20px;
  transition: all 0.25s ease;
  white-space: nowrap;
}

.page-about .mobile-nav__link:hover {
  border-color: var(--gold);
  color: var(--gold);
}

.page-about .mobile-nav__link.is-active {
  background-color: var(--primary);
  border-color: var(--primary);
  color: var(--color-text-primary);
  font-weight: 400;
}

/* ---- 首屏封面 ---- */
.page-about .about-cover {
  position: relative;
  padding: 2.5rem 0 3rem;
  display: flex;
  flex-direction: column;
  gap: 1.5rem;
  border-bottom: 1px solid rgba(255, 215, 0, 0.12);
  overflow: hidden;
}

.page-about .cover__text {
  position: relative;
  z-index: 2;
}

.page-about .cover__title {
  font-family: var(--font-heading);
  font-size: 3.2rem;
  font-weight: 200;
  letter-spacing: 6px;
  text-transform: uppercase;
  color: var(--color-text-primary);
  line-height: 1.1;
  margin: 0 0 0.5rem;
  text-shadow: 0 0 40px rgba(139, 0, 0, 0.3);
}

.page-about .cover__subtitle {
  font-family: var(--font-body);
  font-size: 0.85rem;
  font-weight: 300;
  color: var(--gold);
  letter-spacing: 4px;
  text-transform: uppercase;
  margin: 0 0 0.75rem;
}

.page-about .cover__intro {
  font-family: var(--font-body);
  font-size: 0.95rem;
  font-weight: 300;
  color: var(--color-text-secondary);
  line-height: 1.6;
  max-width: 32em;
  margin: 0;
}

.page-about .cover__image {
  position: relative;
  z-index: 2;
  width: 100%;
  max-width: 320px;
  margin: 0 auto;
}

.page-about .cover__img {
  display: block;
  width: 100%;
  height: auto;
  max-width: 100%;
  object-fit: contain;
  border-radius: 12px;
  box-shadow: 0 20px 40px rgba(0, 0, 0, 0.6);
}

.page-about .cover__accent-line {
  position: absolute;
  top: 1.2rem;
  right: 0;
  width: 30%;
  height: 1px;
  background: linear-gradient(90deg, transparent, var(--gold), transparent);
  opacity: 0.4;
  z-index: 1;
}

.page-about .cover__accent-dot {
  position: absolute;
  bottom: 2rem;
  right: 15%;
  width: 12px;
  height: 12px;
  border-radius: 50%;
  background-color: var(--neon);
  opacity: 0.3;
  z-index: 1;
}

/* ---- 断点装饰 ---- */
.page-about .break-decor {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 1rem;
  padding: 1.5rem 0;
  opacity: 0.35;
}

.page-about .break-decor__line {
  flex: 1;
  height: 1px;
  background: linear-gradient(90deg, transparent, var(--gold), transparent);
  max-width: 120px;
}

.page-about .break-decor__diamond {
  font-size: 0.7rem;
  color: var(--gold);
  font-family: var(--font-body);
}

/* ---- 通用章节 ---- */
.page-about .about-section {
  position: relative;
  padding: 2.5rem 0;
}

.page-about .section__inner {
  position: relative;
  z-index: 2;
  max-width: 720px;
}

.page-about .section__header {
  display: flex;
  align-items: baseline;
  gap: 0.75rem;
  margin-bottom: 1.5rem;
}

.page-about .section__num {
  font-family: var(--font-tech);
  font-size: 1.2rem;
  font-weight: 400;
  color: var(--primary);
  opacity: 0.7;
  letter-spacing: 2px;
}

.page-about .section__title {
  font-family: var(--font-heading);
  font-size: 1.8rem;
  font-weight: 200;
  letter-spacing: 4px;
  text-transform: uppercase;
  color: var(--color-text-primary);
  margin: 0;
  line-height: 1.2;
}

.page-about .section__body {
  padding-left: 0.5rem;
}

.page-about .section__lead {
  font-size: 1.05rem;
  font-weight: 300;
  color: var(--gold);
  margin: 0 0 1rem;
  line-height: 1.6;
}

.page-about .section__text {
  font-size: 0.9rem;
  font-weight: 300;
  color: var(--color-text-secondary);
  line-height: 1.7;
  margin: 0;
}

.page-about .section__decor {
  position: absolute;
  right: 0;
  bottom: 0;
  opacity: 0.08;
  z-index: 0;
  pointer-events: none;
}

/* ---- 核心功能：背景图区 ---- */
.page-about .about-section--features {
  overflow: hidden;
}

.page-about .section__bg {
  position: absolute;
  inset: 0;
  z-index: 0;
  opacity: 0.12;
  pointer-events: none;
}

.page-about .section__bg-img {
  width: 100%;
  height: 100%;
  object-fit: cover;
  object-position: center;
}

/* ---- 功能卡片网格 ---- */
.page-about .features-grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: 1.25rem;
  margin-top: 1.5rem;
}

.page-about .feature-card {
  background-color: rgba(26, 26, 26, 0.7);
  backdrop-filter: blur(4px);
  border: 1px solid rgba(255, 215, 0, 0.08);
  border-radius: 12px;
  padding: 1.5rem 1.25rem;
  transition: all 0.3s ease;
  position: relative;
  overflow: hidden;
}

.page-about .feature-card::before {
  content: '';
  position: absolute;
  top: 0;
  left: 0;
  width: 4px;
  height: 100%;
  background: linear-gradient(180deg, var(--primary), var(--gold));
  opacity: 0;
  transition: opacity 0.3s ease;
}

.page-about .feature-card:hover {
  border-color: rgba(255, 215, 0, 0.25);
  transform: translateY(-3px);
  box-shadow: 0 12px 30px rgba(0, 0, 0, 0.5);
}

.page-about .feature-card:hover::before {
  opacity: 1;
}

.page-about .feature-card__icon {
  margin-bottom: 0.75rem;
}

.page-about .feature-card__title {
  font-family: var(--font-heading);
  font-size: 1.1rem;
  font-weight: 400;
  color: var(--color-text-primary);
  margin: 0 0 0.5rem;
  letter-spacing: 1px;
}

.page-about .feature-card__desc {
  font-size: 0.85rem;
  font-weight: 300;
  color: var(--color-text-secondary);
  line-height: 1.6;
  margin: 0;
}

/* ---- 用户价值 ---- */
.page-about .about-section--value {
  padding-bottom: 3rem;
}

.page-about .value-content {
  display: flex;
  flex-direction: column;
  gap: 1.5rem;
  margin-top: 1rem;
}

.page-about .value__lead {
  font-size: 0.95rem;
  font-weight: 300;
  color: var(--color-text-secondary);
  margin: 0 0 1rem;
}

.page-about .value__list {
  list-style: none;
  padding: 0;
  margin: 0;
  display: flex;
  flex-direction: column;
  gap: 1rem;
}

.page-about .value__item {
  display: flex;
  align-items: flex-start;
  gap: 0.75rem;
  padding: 0.75rem 1rem;
  background-color: rgba(0, 191, 255, 0.04);
  border-radius: 8px;
  border-left: 3px solid var(--neon);
  font-size: 0.9rem;
  font-weight: 300;
  color: var(--color-text-secondary);
  line-height: 1.6;
}

.page-about .value__item-icon {
  font-size: 1.1rem;
  flex-shrink: 0;
  margin-top: 0.1rem;
}

.page-about .value__item strong {
  color: var(--color-text-primary);
  font-weight: 400;
}

.page-about .value__image {
  width: 100%;
  max-width: 320px;
  margin: 0 auto;
}

.page-about .value__img {
  display: block;
  width: 100%;
  height: auto;
  max-width: 100%;
  object-fit: contain;
  border-radius: 12px;
  box-shadow: 0 12px 30px rgba(0, 0, 0, 0.5);
}

/* ---- 底部导航 ---- */
.page-about .canvas__footer-nav {
  margin-top: 1rem;
  padding: 1.5rem 0 2.5rem;
  border-top: 1px solid rgba(255, 215, 0, 0.1);
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 0.75rem;
  text-align: center;
}

.page-about .footer-nav__label {
  font-family: var(--font-heading);
  font-size: 0.7rem;
  font-weight: 300;
  color: var(--color-text-secondary);
  letter-spacing: 3px;
  text-transform: uppercase;
}

.page-about .footer-nav__links {
  display: flex;
  align-items: center;
  gap: 0.5rem;
  flex-wrap: wrap;
  justify-content: center;
}

.page-about .footer-nav__link {
  color: var(--gold);
  text-decoration: none;
  font-size: 0.85rem;
  font-weight: 300;
  transition: color 0.2s ease;
  letter-spacing: 1px;
}

.page-about .footer-nav__link:hover {
  color: var(--color-text-primary);
  text-decoration: underline;
}

.page-about .footer-nav__sep {
  color: var(--color-text-secondary);
  font-size: 0.7rem;
  opacity: 0.5;
}

/* ============================================= */
/* 桌面端样式 (min-width: 768px)                  */
/* ============================================= */
@media (min-width: 768px) {
  .page-about .about-canvas {
    flex-direction: row;
    align-items: flex-start;
  }

  .page-about .canvas__sidebar {
    display: flex;
    flex-direction: column;
    position: sticky;
    top: calc(var(--header-height, 60px) + 1rem);
    width: var(--sidebar-width);
    min-width: var(--sidebar-width);
    height: calc(100vh - var(--header-height, 60px) - 2rem);
    align-self: flex-start;
    border-right: 1px solid rgba(255, 215, 0, 0.15);
    border-radius: 0 12px 12px 0;
    margin-right: 2rem;
    padding: 2.5rem 1.8rem;
  }

  .page-about .canvas__main {
    padding: 0 1.5rem 0 0;
    flex: 1;
    min-width: 0;
  }

  .page-about .canvas__mobile-nav {
    display: none;
  }

  .page-about .about-cover {
    flex-direction: row;
    align-items: center;
    justify-content: space-between;
    padding: 3.5rem 0 4rem;
    gap: 2rem;
  }

  .page-about .cover__text {
    flex: 1;
  }

  .page-about .cover__title {
    font-size: 4.5rem;
    letter-spacing: 10px;
  }

  .page-about .cover__subtitle {
    font-size: 1rem;
    letter-spacing: 6px;
  }

  .page-about .cover__intro {
    font-size: 1.05rem;
  }

  .page-about .cover__image {
    max-width: 360px;
    flex-shrink: 0;
  }

  .page-about .cover__accent-line {
    width: 20%;
    top: 2rem;
  }

  .page-about .cover__accent-dot {
    bottom: 3rem;
    right: 10%;
    width: 16px;
    height: 16px;
  }

  .page-about .about-section {
    padding: 3.5rem 0;
  }

  .page-about .section__title {
    font-size: 2.2rem;
    letter-spacing: 6px;
  }

  .page-about .section__num {
    font-size: 1.5rem;
  }

  .page-about .features-grid {
    grid-template-columns: repeat(3, 1fr);
    gap: 1.5rem;
  }

  .page-about .feature-card {
    padding: 1.8rem 1.5rem;
  }

  .page-about .value-content {
    flex-direction: row;
    align-items: flex-start;
    gap: 2.5rem;
  }

  .page-about .value__text {
    flex: 1;
  }

  .page-about .value__image {
    max-width: 300px;
    flex-shrink: 0;
  }

  .page-about .canvas__footer-nav {
    flex-direction: row;
    justify-content: space-between;
    padding: 1.5rem 0 3rem;
  }

  .page-about .break-decor {
    padding: 2rem 0;
  }
}

/* ============================================= */
/* 大桌面端 (min-width: 1024px)                   */
/* ============================================= */
@media (min-width: 1024px) {
  .page-about .cover__title {
    font-size: 5.5rem;
  }

  .page-about .cover__image {
    max-width: 400px;
  }

  .page-about .section__inner {
    max-width: 800px;
  }

  .page-about .section__title {
    font-size: 2.5rem;
  }

  .page-about .canvas__sidebar {
    padding: 3rem 2rem;
    margin-right: 3rem;
  }
}

/* ============================================= */
/* 滚动淡入交互 (渐进增强)                          */
/* ============================================= */
.page-about .about-section {
  opacity: 1;
  transition: opacity 0.6s ease, transform 0.6s ease;
  transform: translateY(0);
}

.page-about .about-section[data-scroll-section]:not(.is-visible) {
  opacity: 0.6;
  transform: translateY(12px);
}

.page-about .about-section[data-scroll-section].is-visible {
  opacity: 1;
  transform: translateY(0);
}

/* 侧栏链接高亮配合滚动 */
.page-about .sidebar__link.is-active {
  color: var(--gold);
  border-left-color: var(--gold);
}

/* 确保图片响应 */
.page-about img {
  max-width: 100%;
  height: auto;
}

/* 窄屏不溢出 */
.page-about .canvas__main,
.page-about .about-canvas {
  overflow-x: hidden;
}

/* 打印优化 */
@media print {
  .page-about .canvas__sidebar,
  .page-about .canvas__mobile-nav,
  .page-about .page-progress,
  .page-about .break-decor {
    display: none !important;
  }
  .page-about .about-canvas {
    display: block;
  }
  .page-about .canvas__main {
    padding: 0;
  }
  .page-about .cover__title {
    font-size: 2.5rem;
  }
}