/* ============================================
   page-about 专属样式 — 移动端优先
   ============================================ */
.page-about {
  --exhibit-gap: 2rem;
  --exhibit-padding: 2rem 1.25rem;
  --aside-width: 3rem;
  --accent-glow: 0 0 12px rgba(138, 43, 226, 0.25);
  position: relative;
  display: flex;
  flex-direction: column;
  background: var(--color-bg, #0D0D2B);
  color: var(--color-text, #E0E0FF);
  font-family: var(--font-body, 'PingFang SC', 'Noto Sans SC', sans-serif);
  line-height: 1.6;
  min-height: 100vh;
  padding-top: calc(var(--header-height, 68px) + 0.5rem);
  padding-bottom: 4rem;
}

/* ---------- 面包屑 ---------- */
.about-breadcrumb {
  display: flex;
  align-items: center;
  flex-wrap: wrap;
  gap: 0.5rem;
  padding: 0.75rem 1.25rem;
  font-size: 0.8rem;
  font-family: var(--font-pixel, 'Courier New', monospace);
  color: var(--color-secondary, #00BFFF);
  border-bottom: 1px solid var(--color-border, #4B0082);
  margin-bottom: 1.5rem;
}
.about-breadcrumb__link {
  color: var(--color-secondary, #00BFFF);
  text-decoration: none;
  transition: color 0.2s;
}
.about-breadcrumb__link:hover {
  color: var(--color-accent, #FFA500);
}
.about-breadcrumb__separator {
  color: var(--color-primary, #8A2BE2);
  font-size: 0.6rem;
}
.about-breadcrumb__current {
  color: var(--color-heading, #FFFFFF);
  font-weight: 600;
}

/* ---------- 英雄区 ---------- */
.about-hero {
  padding: 2rem 1.25rem 1.5rem;
  background: linear-gradient(135deg, rgba(10,10,40,0.92) 0%, rgba(30,10,60,0.88) 100%);
  border-bottom: 2px solid var(--color-primary, #8A2BE2);
  position: relative;
}
.about-hero__frame {
  position: relative;
  max-width: var(--max-width, 1200px);
  margin: 0 auto;
}
.about-hero__badge {
  display: inline-block;
  font-family: var(--font-pixel, 'Courier New', monospace);
  font-size: 0.7rem;
  letter-spacing: 0.3em;
  color: var(--color-accent, #FFA500);
  writing-mode: vertical-rl;
  text-orientation: upright;
  position: absolute;
  left: -0.25rem;
  top: 0;
  opacity: 0.7;
  transform: translateX(-100%);
}
.about-hero__title {
  font-family: var(--font-heading, 'Courier New', monospace);
  font-size: 2rem;
  font-weight: 700;
  color: var(--color-heading, #FFFFFF);
  margin: 0 0 0.5rem 0;
  line-height: 1.2;
  letter-spacing: 0.04em;
}
.about-hero__desc {
  font-size: 0.95rem;
  color: var(--color-secondary, #00BFFF);
  margin: 0;
  max-width: 32em;
  border-left: 3px solid var(--color-primary, #8A2BE2);
  padding-left: 1rem;
}

/* ---------- 章节导航 ---------- */
.about-section-nav {
  display: none;  /* 移动端隐藏 */
  position: fixed;
  right: 1rem;
  top: 50%;
  transform: translateY(-50%);
  z-index: 50;
  background: rgba(13,13,43,0.85);
  border: 1px solid var(--color-border, #4B0082);
  border-radius: 2px;
  padding: 0.75rem 0.5rem;
  backdrop-filter: blur(4px);
  -webkit-backdrop-filter: blur(4px);
}
.section-nav__list {
  list-style: none;
  margin: 0;
  padding: 0;
  display: flex;
  flex-direction: column;
  gap: 0.75rem;
}
.section-nav__link {
  display: block;
  font-family: var(--font-pixel, 'Courier New', monospace);
  font-size: 0.7rem;
  color: var(--color-text, #E0E0FF);
  text-decoration: none;
  writing-mode: vertical-rl;
  text-orientation: upright;
  letter-spacing: 0.2em;
  padding: 0.25rem 0.15rem;
  transition: color 0.2s, background 0.2s;
  border-radius: 1px;
}
.section-nav__link:hover {
  color: var(--color-accent, #FFA500);
  background: rgba(138,43,226,0.15);
}

/* ---------- 展览章节 ---------- */
.about-exhibit {
  display: flex;
  flex-direction: column;
  gap: 1rem;
  padding: var(--exhibit-padding);
  border-bottom: 1px solid var(--color-border, #4B0082);
  position: relative;
  background: transparent;
  transition: background 0.3s;
}
.about-exhibit:last-of-type {
  border-bottom: 2px solid var(--color-primary, #8A2BE2);
}

/* 左侧纵向区域 */
.exhibit__aside {
  display: flex;
  flex-direction: row;
  align-items: center;
  gap: 0.75rem;
  padding-bottom: 0.5rem;
  border-bottom: 1px dashed var(--color-border, #4B0082);
}
.exhibit__number {
  font-family: var(--font-pixel, 'Courier New', monospace);
  font-size: 1.4rem;
  font-weight: 700;
  color: var(--color-primary, #8A2BE2);
  line-height: 1;
}
.exhibit__label {
  font-family: var(--font-pixel, 'Courier New', monospace);
  font-size: 0.65rem;
  letter-spacing: 0.3em;
  color: var(--color-secondary, #00BFFF);
  opacity: 0.7;
}

/* 主体区 */
.exhibit__body {
  flex: 1;
}
.exhibit__title {
  font-family: var(--font-heading, 'Courier New', monospace);
  font-size: 1.6rem;
  font-weight: 700;
  color: var(--color-heading, #FFFFFF);
  margin: 0 0 1rem 0;
  line-height: 1.3;
  position: relative;
  padding-left: 0.75rem;
  border-left: 3px solid var(--color-accent, #FFA500);
}
.exhibit__content {
  display: flex;
  flex-direction: column;
  gap: 1.25rem;
}
.exhibit__text {
  margin: 0;
  font-size: 0.95rem;
  color: var(--color-text, #E0E0FF);
  max-width: 65ch;
}
.exhibit__media {
  width: 100%;
  border: 1px solid var(--color-border, #4B0082);
  background: var(--color-surface, #1A1A3E);
  padding: 0.5rem;
  box-shadow: var(--accent-glow);
}
.exhibit__img {
  display: block;
  width: 100%;
  height: auto;
  max-width: 100%;
  object-fit: cover;
  aspect-ratio: attr(width) / attr(height);
}

/* 反向章节（资料优势）图片优先 */
.about-exhibit--reverse .exhibit__content {
  flex-direction: column;
}

/* ---------- 内部链接区 ---------- */
.about-links {
  padding: 2.5rem 1.25rem;
  text-align: center;
  background: radial-gradient(ellipse at center, rgba(138,43,226,0.08) 0%, transparent 70%);
  border-top: 1px solid var(--color-border, #4B0082);
}
.about-links__title {
  font-family: var(--font-heading, 'Courier New', monospace);
  font-size: 1.2rem;
  font-weight: 400;
  color: var(--color-heading, #FFFFFF);
  margin: 0 0 1.25rem 0;
  letter-spacing: 0.1em;
}
.about-links__list {
  list-style: none;
  margin: 0;
  padding: 0;
  display: flex;
  flex-wrap: wrap;
  justify-content: center;
  gap: 0.75rem 1.5rem;
}
.about-links__link {
  font-family: var(--font-pixel, 'Courier New', monospace);
  font-size: 0.85rem;
  color: var(--color-secondary, #00BFFF);
  text-decoration: none;
  padding: 0.4rem 1rem;
  border: 1px solid var(--color-border, #4B0082);
  background: rgba(13,13,43,0.6);
  transition: all 0.25s;
  display: inline-block;
}
.about-links__link:hover {
  color: var(--color-accent, #FFA500);
  border-color: var(--color-primary, #8A2BE2);
  background: rgba(138,43,226,0.12);
  box-shadow: 0 0 10px rgba(138,43,226,0.2);
}

/* ---------- 进度条 & 返回顶部 ---------- */
.progress-bar {
  position: fixed;
  top: 0;
  left: 0;
  height: 3px;
  background: linear-gradient(90deg, var(--color-primary, #8A2BE2), var(--color-accent, #FFA500));
  z-index: 999;
  width: 0%;
  pointer-events: none;
  transition: width 0.05s linear;
}
.scroll-top {
  position: fixed;
  bottom: 1.5rem;
  right: 1.25rem;
  z-index: 100;
  width: 2.8rem;
  height: 2.8rem;
  border: 1px solid var(--color-primary, #8A2BE2);
  background: rgba(13,13,43,0.85);
  color: var(--color-primary, #8A2BE2);
  font-size: 1.4rem;
  font-family: var(--font-pixel, 'Courier New', monospace);
  cursor: pointer;
  display: flex;
  align-items: center;
  justify-content: center;
  transition: all 0.25s;
  backdrop-filter: blur(4px);
  -webkit-backdrop-filter: blur(4px);
  opacity: 0;
  visibility: hidden;
}
.scroll-top[data-visible] {
  opacity: 1;
  visibility: visible;
}
.scroll-top:hover {
  background: var(--color-primary, #8A2BE2);
  color: var(--color-dark, #0D0D2B);
  border-color: var(--color-accent, #FFA500);
}

/* ============================================
   桌面端 (>= 768px)
   ============================================ */
@media (min-width: 768px) {
  .page-about {
    padding-top: calc(var(--header-height, 68px) + 1.5rem);
    padding-bottom: 5rem;
  }

  .about-breadcrumb {
    padding: 1rem 2.5rem;
    font-size: 0.85rem;
  }

  .about-hero {
    padding: 3.5rem 2.5rem 2.5rem;
  }
  .about-hero__badge {
    font-size: 0.85rem;
    left: -0.5rem;
  }
  .about-hero__title {
    font-size: 3rem;
  }
  .about-hero__desc {
    font-size: 1.1rem;
  }

  /* 显示章节导航 */
  .about-section-nav {
    display: block;
  }

  /* 展览章节：横向布局 */
  .about-exhibit {
    flex-direction: row;
    gap: 2.5rem;
    padding: 3rem 2.5rem;
    max-width: var(--max-width, 1200px);
    margin-left: auto;
    margin-right: auto;
    width: 100%;
  }

  .exhibit__aside {
    flex-direction: column;
    align-items: flex-end;
    gap: 0.5rem;
    min-width: var(--aside-width);
    width: var(--aside-width);
    border-bottom: none;
    border-right: 1px solid var(--color-border, #4B0082);
    padding-bottom: 0;
    padding-right: 1rem;
    padding-top: 0.25rem;
  }
  .exhibit__number {
    font-size: 1.8rem;
    writing-mode: vertical-rl;
    text-orientation: upright;
  }
  .exhibit__label {
    writing-mode: vertical-rl;
    text-orientation: upright;
    font-size: 0.7rem;
    letter-spacing: 0.4em;
    line-height: 1.4;
  }

  .exhibit__body {
    padding-left: 0.5rem;
  }
  .exhibit__title {
    font-size: 2rem;
    padding-left: 1rem;
    margin-bottom: 1.5rem;
  }

  /* 内容图文错位 — 默认文字左，图片右 */
  .exhibit__content {
    flex-direction: row;
    flex-wrap: wrap;
    align-items: flex-start;
    gap: 2rem;
  }
  .exhibit__text {
    flex: 1 1 45%;
    font-size: 1rem;
  }
  .exhibit__media {
    flex: 1 1 45%;
    max-width: 50%;
  }

  /* 反向章节：图片左，文字右 */
  .about-exhibit--reverse .exhibit__content {
    flex-direction: row-reverse;
  }
  .about-exhibit--reverse .exhibit__text {
    flex: 1 1 45%;
  }
  .about-exhibit--reverse .exhibit__media {
    flex: 1 1 45%;
    max-width: 50%;
  }

  /* 更新承诺章节：纵向排列，图片在下 */
  #updates.exhibit__content {
    flex-direction: column;
  }
  #updates .exhibit__text {
    flex: none;
    max-width: 65ch;
  }
  #updates .exhibit__media {
    flex: none;
    max-width: 70%;
  }

  .about-links {
    padding: 3.5rem 2.5rem;
  }
  .about-links__title {
    font-size: 1.5rem;
  }
  .about-links__list {
    gap: 1rem 2.5rem;
  }
  .about-links__link {
    font-size: 0.95rem;
    padding: 0.5rem 1.5rem;
  }

  .scroll-top {
    bottom: 2rem;
    right: 2rem;
    width: 3.2rem;
    height: 3.2rem;
    font-size: 1.6rem;
  }
}

/* ============================================
   大桌面 (>= 1024px) 更宽敞
   ============================================ */
@media (min-width: 1024px) {
  .about-hero {
    padding: 5rem 3rem 3rem;
  }
  .about-hero__title {
    font-size: 3.6rem;
  }
  .about-exhibit {
    padding: 4rem 3rem;
    gap: 3.5rem;
  }
  .exhibit__aside {
    min-width: 4rem;
    width: 4rem;
  }
  .exhibit__number {
    font-size: 2.2rem;
  }
  .exhibit__title {
    font-size: 2.4rem;
  }
  .exhibit__text {
    font-size: 1.05rem;
  }
}