/* ============================================================
   page-about ：品牌介绍页专属样式
   作用域限定 .page-about，移动端优先，桌面端增强。
   ============================================================ */
.page-about {
  /* 页面级设计变量 —— 仅在此作用域生效 */
  --about-hero-overlay: linear-gradient(135deg, rgba(10,10,26,0.92) 30%, rgba(255,42,42,0.18) 100%);
  --about-card-skew: rotate(-1deg);
  --about-card-skew-hover: rotate(0deg) scale(1.02);
  --about-gold-glow: 0 0 30px rgba(255,215,0,0.20);
  --about-divider-color: rgba(255,215,0,0.25);

  display: block;
  width: 100%;
  max-width: 100%;
  padding: 0;
  margin: 0;
  color: var(--color-text, #FFFFFF);
  font-family: var(--font-body, 'Inter','Roboto',sans-serif);
  line-height: 1.6;
  background-color: var(--color-bg, #0A0A1A);
}

/* ---------- 面包屑 ---------- */
.about-breadcrumb {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 0.35rem;
  padding: 1rem 1.25rem 0.25rem;
  font-size: 0.85rem;
  color: var(--color-text-secondary, #B0B0B0);
  max-width: 1200px;
  margin: 0 auto;
}
.about-breadcrumb a {
  color: var(--color-secondary, #00BFFF);
  text-decoration: none;
  transition: color var(--transition, 0.25s ease);
}
.about-breadcrumb a:hover,
.about-breadcrumb a:focus-visible {
  color: var(--color-primary, #FF2A2A);
  text-decoration: underline;
}
.about-breadcrumb-sep {
  color: var(--color-text-secondary, #B0B0B0);
  margin: 0 0.15rem;
}
.about-breadcrumb [aria-current="page"] {
  color: var(--color-accent, #FFD700);
  font-weight: 500;
}

/* ---------- 首屏封面 ---------- */
.about-hero {
  position: relative;
  padding: 1.5rem 1.25rem 2.5rem;
  max-width: 1200px;
  margin: 0 auto;
}
.about-hero-inner {
  display: flex;
  flex-direction: column;
  gap: 1.75rem;
}
.about-hero-text {
  order: 1;
  display: flex;
  flex-direction: column;
  gap: 0.75rem;
}
.about-hero-title {
  font-family: var(--font-heading, 'Orbitron',sans-serif);
  font-size: 2.4rem;
  font-weight: 700;
  line-height: 1.15;
  color: var(--color-accent, #FFD700);
  text-shadow: 0 0 30px rgba(255,215,0,0.25);
  margin: 0;
  letter-spacing: 0.02em;
  background: linear-gradient(135deg, #FFD700 0%, #FF8C00 100%);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}
.about-hero-subtitle {
  font-family: var(--font-heading, 'Orbitron',sans-serif);
  font-size: 1rem;
  font-weight: 400;
  color: var(--color-secondary, #00BFFF);
  letter-spacing: 0.08em;
  text-transform: uppercase;
  margin: 0;
  opacity: 0.9;
}
.about-hero-desc {
  font-size: 1rem;
  color: var(--color-text-secondary, #B0B0B0);
  max-width: 60ch;
  margin: 0;
  line-height: 1.7;
}
.about-hero-actions {
  display: flex;
  flex-wrap: wrap;
  gap: 1rem;
  padding-top: 0.5rem;
}
.about-hero-cta {
  display: inline-block;
  padding: 0.7rem 1.8rem;
  font-family: var(--font-heading, 'Orbitron',sans-serif);
  font-weight: 600;
  font-size: 0.9rem;
  color: var(--color-text, #FFFFFF);
  background: var(--color-primary, #FF2A2A);
  border: var(--border-thick, 3px) solid var(--color-primary, #FF2A2A);
  border-radius: var(--radius-sm, 4px);
  text-decoration: none;
  text-transform: uppercase;
  letter-spacing: 0.04em;
  transition: all var(--transition, 0.25s ease);
  box-shadow: 0 0 20px rgba(255,42,42,0.25);
}
.about-hero-cta:hover,
.about-hero-cta:focus-visible {
  background: transparent;
  color: var(--color-primary, #FF2A2A);
  box-shadow: 0 0 40px rgba(255,42,42,0.35);
}
.about-hero-link {
  display: inline-block;
  padding: 0.7rem 1.2rem;
  font-family: var(--font-body, 'Inter','Roboto',sans-serif);
  font-weight: 500;
  font-size: 0.9rem;
  color: var(--color-secondary, #00BFFF);
  border: var(--border-thick, 3px) solid transparent;
  border-radius: var(--radius-sm, 4px);
  text-decoration: none;
  transition: all var(--transition, 0.25s ease);
}
.about-hero-link:hover,
.about-hero-link:focus-visible {
  border-color: var(--color-secondary, #00BFFF);
  color: var(--color-accent, #FFD700);
}
.about-hero-visual {
  order: 0;
  position: relative;
  border-radius: var(--radius-md, 8px);
  overflow: hidden;
  box-shadow: var(--shadow-strong, 0 8px 32px rgba(0,0,0,0.6));
  border: var(--border-thick, 3px) solid var(--color-surface, #1A1A2E);
  background: var(--color-surface, #1A1A2E);
}
.about-hero-img {
  display: block;
  width: 100%;
  height: auto;
  max-width: 100%;
  object-fit: cover;
  aspect-ratio: 800 / 600;
}

/* ---------- 通用章节标题 ---------- */
.about-section-title {
  font-family: var(--font-heading, 'Orbitron',sans-serif);
  font-size: 1.6rem;
  font-weight: 700;
  color: var(--color-text, #FFFFFF);
  margin: 0 0 1rem;
  letter-spacing: 0.02em;
  position: relative;
  padding-bottom: 0.6rem;
}
.about-section-title::after {
  content: '';
  position: absolute;
  bottom: 0;
  left: 0;
  width: 60px;
  height: var(--border-thick, 3px);
  background: var(--color-accent, #FFD700);
  box-shadow: 0 0 12px rgba(255,215,0,0.35);
}

/* ---------- 使命区 ---------- */
.about-mission {
  padding: 2.5rem 1.25rem;
  max-width: 1200px;
  margin: 0 auto;
}
.about-mission-body {
  display: flex;
  flex-direction: column;
  gap: 1rem;
  background: var(--color-surface, #1A1A2E);
  border-left: 4px solid var(--color-primary, #FF2A2A);
  padding: 1.25rem 1.5rem;
  border-radius: 0 var(--radius-md, 8px) var(--radius-md, 8px) 0;
  box-shadow: var(--shadow-strong, 0 8px 32px rgba(0,0,0,0.6));
}
.about-mission-text {
  font-size: 1rem;
  color: var(--color-text-secondary, #B0B0B0);
  margin: 0;
  line-height: 1.75;
}
.about-mission-text:first-of-type {
  font-size: 1.05rem;
  color: var(--color-text, #FFFFFF);
  font-weight: 400;
}

/* ---------- 核心功能卡片区 ---------- */
.about-features {
  padding: 2.5rem 1.25rem 3rem;
  max-width: 1200px;
  margin: 0 auto;
}
.about-features-grid {
  display: flex;
  flex-direction: column;
  gap: 1.5rem;
  margin-top: 1.5rem;
}

/* 单张卡片 */
.about-feature-card {
  position: relative;
  background: var(--color-surface, #1A1A2E);
  border: var(--border-thick, 3px) solid var(--color-surface, #1A1A2E);
  border-radius: var(--radius-md, 8px);
  padding: 1.5rem 1.25rem;
  box-shadow: var(--shadow-strong, 0 8px 32px rgba(0,0,0,0.6));
  transition: all var(--transition, 0.25s ease);
  display: flex;
  flex-direction: column;
  gap: 0.6rem;
  transform: var(--about-card-skew);
  /* 加载时依次淡入动画 */
  animation: aboutFadeInUp 0.5s ease backwards;
}
.about-feature-card:nth-child(1) { animation-delay: 0.05s; }
.about-feature-card:nth-child(2) { animation-delay: 0.20s; }
.about-feature-card:nth-child(3) { animation-delay: 0.35s; }

.about-feature-card:hover,
.about-feature-card:focus-within {
  transform: var(--about-card-skew-hover);
  border-color: var(--color-secondary, #00BFFF);
  box-shadow: var(--shadow-glow, 0 0 30px rgba(0,191,255,0.25));
}
.about-feature-card-icon {
  width: 100%;
  max-width: 60px;
  height: auto;
  margin-bottom: 0.25rem;
  border-radius: var(--radius-sm, 4px);
  overflow: hidden;
  border: 2px solid var(--color-accent, #FFD700);
  background: var(--color-bg, #0A0A1A);
}
.about-feature-icon-img {
  display: block;
  width: 100%;
  height: auto;
  max-width: 100%;
  object-fit: contain;
  aspect-ratio: 1 / 1;
}
.about-feature-card-title {
  font-family: var(--font-heading, 'Orbitron',sans-serif);
  font-size: 1.15rem;
  font-weight: 600;
  color: var(--color-text, #FFFFFF);
  margin: 0;
  letter-spacing: 0.02em;
}
.about-feature-card-desc {
  font-size: 0.95rem;
  color: var(--color-text-secondary, #B0B0B0);
  margin: 0;
  line-height: 1.6;
  flex: 1;
}
.about-feature-card-link {
  display: inline-block;
  font-family: var(--font-body, 'Inter','Roboto',sans-serif);
  font-weight: 500;
  font-size: 0.9rem;
  color: var(--color-accent, #FFD700);
  text-decoration: none;
  padding: 0.3rem 0;
  border-bottom: 2px solid transparent;
  transition: all var(--transition, 0.25s ease);
  align-self: flex-start;
}
.about-feature-card-link:hover,
.about-feature-card-link:focus-visible {
  border-bottom-color: var(--color-accent, #FFD700);
  color: var(--color-primary, #FF2A2A);
}

/* ---------- 数据来源区 ---------- */
.about-data {
  padding: 2.5rem 1.25rem;
  max-width: 1200px;
  margin: 0 auto;
}
.about-data-inner {
  display: flex;
  flex-direction: column;
  gap: 1.5rem;
  background: var(--color-surface, #1A1A2E);
  border-radius: var(--radius-md, 8px);
  padding: 1.5rem;
  box-shadow: var(--shadow-strong, 0 8px 32px rgba(0,0,0,0.6));
  border: var(--border-thick, 3px) solid rgba(0,191,255,0.15);
}
.about-data-visual {
  border-radius: var(--radius-sm, 4px);
  overflow: hidden;
  background: var(--color-bg, #0A0A1A);
  border: 2px solid var(--color-secondary, #00BFFF);
}
.about-data-img {
  display: block;
  width: 100%;
  height: auto;
  max-width: 100%;
  object-fit: cover;
  aspect-ratio: 800 / 400;
}
.about-data-text {
  display: flex;
  flex-direction: column;
  gap: 1rem;
}
.about-data-text-item {
  font-size: 0.95rem;
  color: var(--color-text-secondary, #B0B0B0);
  margin: 0;
  line-height: 1.7;
  padding-left: 0.75rem;
  border-left: 2px solid var(--about-divider-color);
}

/* ---------- 品牌信任提示 ---------- */
.about-trust {
  padding: 1.5rem 1.25rem 0.5rem;
  max-width: 1200px;
  margin: 0 auto;
}
.about-trust-inner {
  background: linear-gradient(135deg, rgba(255,42,42,0.08) 0%, rgba(0,191,255,0.06) 100%);
  border: var(--border-thick, 3px) solid rgba(255,215,0,0.18);
  border-radius: var(--radius-md, 8px);
  padding: 1.25rem 1.5rem;
}
.about-trust-text {
  font-size: 0.9rem;
  color: var(--color-text-secondary, #B0B0B0);
  margin: 0;
  line-height: 1.7;
  text-align: center;
}

/* ---------- 内部链接导航 ---------- */
.about-links {
  display: flex;
  flex-wrap: wrap;
  justify-content: center;
  gap: 0.75rem 1.5rem;
  padding: 2rem 1.25rem 2.5rem;
  max-width: 1200px;
  margin: 0 auto;
}
.about-links-item {
  font-family: var(--font-heading, 'Orbitron',sans-serif);
  font-weight: 500;
  font-size: 0.9rem;
  color: var(--color-secondary, #00BFFF);
  text-decoration: none;
  padding: 0.4rem 0.8rem;
  border: 2px solid transparent;
  border-radius: var(--radius-sm, 4px);
  transition: all var(--transition, 0.25s ease);
  text-transform: uppercase;
  letter-spacing: 0.04em;
}
.about-links-item:hover,
.about-links-item:focus-visible {
  border-color: var(--color-accent, #FFD700);
  color: var(--color-accent, #FFD700);
  background: rgba(255,215,0,0.06);
}

/* ---------- 纯CSS模态框（:target 驱动） ---------- */
.about-modal {
  position: fixed;
  inset: 0;
  z-index: 1000;
  display: flex;
  align-items: center;
  justify-content: center;
  visibility: hidden;
  opacity: 0;
  transition: opacity 0.3s ease, visibility 0.3s ease;
  pointer-events: none;
}
.about-modal:target {
  visibility: visible;
  opacity: 1;
  pointer-events: all;
}
.about-modal-overlay {
  position: absolute;
  inset: 0;
  background: rgba(10,10,26,0.85);
  backdrop-filter: blur(6px);
  -webkit-backdrop-filter: blur(6px);
}
.about-modal-content {
  position: relative;
  z-index: 1;
  background: var(--color-surface, #1A1A2E);
  border: var(--border-thick, 3px) solid var(--color-accent, #FFD700);
  border-radius: var(--radius-md, 8px);
  padding: 2rem 1.5rem 1.5rem;
  max-width: 520px;
  width: calc(100% - 2rem);
  max-height: 80vh;
  overflow-y: auto;
  box-shadow: var(--shadow-glow, 0 0 30px rgba(0,191,255,0.25)), var(--shadow-strong, 0 8px 32px rgba(0,0,0,0.6));
  animation: aboutModalIn 0.3s ease backwards;
}
.about-modal-close {
  position: absolute;
  top: 0.75rem;
  right: 1rem;
  font-size: 1.6rem;
  font-weight: 700;
  color: var(--color-text-secondary, #B0B0B0);
  text-decoration: none;
  line-height: 1;
  transition: color var(--transition, 0.25s ease);
}
.about-modal-close:hover,
.about-modal-close:focus-visible {
  color: var(--color-primary, #FF2A2A);
}
.about-modal-title {
  font-family: var(--font-heading, 'Orbitron',sans-serif);
  font-size: 1.3rem;
  font-weight: 600;
  color: var(--color-accent, #FFD700);
  margin: 0 0 0.75rem;
  letter-spacing: 0.02em;
}
.about-modal-body {
  font-size: 0.95rem;
  color: var(--color-text-secondary, #B0B0B0);
  line-height: 1.7;
  display: flex;
  flex-direction: column;
  gap: 0.75rem;
  margin-bottom: 1.25rem;
}
.about-modal-body p {
  margin: 0;
}
.about-modal-btn {
  display: inline-block;
  padding: 0.5rem 1.5rem;
  font-family: var(--font-body, 'Inter','Roboto',sans-serif);
  font-weight: 500;
  font-size: 0.9rem;
  color: var(--color-text, #FFFFFF);
  background: var(--color-primary, #FF2A2A);
  border: 2px solid var(--color-primary, #FF2A2A);
  border-radius: var(--radius-sm, 4px);
  text-decoration: none;
  transition: all var(--transition, 0.25s ease);
  cursor: pointer;
}
.about-modal-btn:hover,
.about-modal-btn:focus-visible {
  background: transparent;
  color: var(--color-primary, #FF2A2A);
}

/* ---------- 动画关键帧 ---------- */
@keyframes aboutFadeInUp {
  0% {
    opacity: 0;
    transform: var(--about-card-skew) translateY(20px);
  }
  100% {
    opacity: 1;
    transform: var(--about-card-skew) translateY(0);
  }
}
@keyframes aboutModalIn {
  0% {
    opacity: 0;
    transform: scale(0.92) translateY(12px);
  }
  100% {
    opacity: 1;
    transform: scale(1) translateY(0);
  }
}

/* ============================================================
   桌面端增强（≥768px）
   ============================================================ */
@media (min-width: 768px) {
  .about-breadcrumb {
    padding: 1.5rem 2rem 0.5rem;
  }

  /* 首屏：左文右图双列 */
  .about-hero {
    padding: 2rem 2rem 3rem;
  }
  .about-hero-inner {
    flex-direction: row;
    align-items: center;
    gap: 2.5rem;
  }
  .about-hero-text {
    order: 0;
    flex: 1 1 45%;
  }
  .about-hero-title {
    font-size: 3.2rem;
  }
  .about-hero-subtitle {
    font-size: 1.1rem;
  }
  .about-hero-desc {
    font-size: 1.05rem;
  }
  .about-hero-visual {
    order: 1;
    flex: 1 1 50%;
    max-width: 600px;
  }

  /* 使命区 */
  .about-mission {
    padding: 3rem 2rem;
  }
  .about-mission-body {
    padding: 1.5rem 2rem;
    flex-direction: row;
    flex-wrap: wrap;
  }
  .about-mission-text {
    flex: 1 1 40%;
  }
  .about-mission-text:first-of-type {
    flex: 1 1 100%;
  }

  /* 功能卡片：三列对角线网格 */
  .about-features {
    padding: 3rem 2rem 3.5rem;
  }
  .about-features-grid {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 1.5rem;
  }
  .about-feature-card {
    padding: 1.75rem 1.5rem;
  }
  /* 对角线偏移：中间卡片下沉，右侧卡片再下沉 */
  .about-feature-card:nth-child(2) {
    margin-top: 2rem;
  }
  .about-feature-card:nth-child(3) {
    margin-top: 3.5rem;
  }

  /* 数据来源区：双列并排 */
  .about-data {
    padding: 3rem 2rem;
  }
  .about-data-inner {
    flex-direction: row;
    align-items: flex-start;
    gap: 2rem;
    padding: 2rem;
  }
  .about-data-visual {
    flex: 1 1 45%;
    max-width: 500px;
  }
  .about-data-text {
    flex: 1 1 50%;
  }

  /* 信任区 */
  .about-trust {
    padding: 2rem 2rem 1rem;
  }

  /* 内部链接 */
  .about-links {
    padding: 2.5rem 2rem 3rem;
    gap: 1rem 2rem;
  }
  .about-links-item {
    font-size: 1rem;
  }

  /* 模态框内容更宽敞 */
  .about-modal-content {
    padding: 2.5rem 2rem 2rem;
    max-width: 580px;
  }
  .about-modal-title {
    font-size: 1.5rem;
  }
}

/* 大屏微调（≥1024px） */
@media (min-width: 1024px) {
  .about-hero-title {
    font-size: 4rem;
  }
  .about-hero-inner {
    gap: 3.5rem;
  }
  .about-hero-desc {
    font-size: 1.1rem;
  }
  .about-section-title {
    font-size: 1.85rem;
  }
  .about-feature-card {
    padding: 2rem 1.75rem;
  }
  .about-feature-card-title {
    font-size: 1.25rem;
  }
}