/* ==============================
   page-about  ·  品牌故事专属样式
   移动端优先，桌面增强
   ============================== */
.page-about {
  --ab-bg-card: #1A1A2E;
  --ab-border-gold: #FFD700;
  --ab-red: #E53935;
  --ab-blue: #1565C0;
  --ab-gold: #FFD700;
  --ab-text: #EAEAEA;
  --ab-muted: #9E9E9E;
  --ab-font-heading: 'Montserrat','PingFang SC','Microsoft YaHei','Helvetica Neue',Arial,sans-serif;
  --ab-font-body: 'Noto Sans SC','PT Mono','Courier New',monospace,'PingFang SC','Microsoft YaHei','Helvetica Neue',Arial,sans-serif;
  --ab-radius: 12px;
  --ab-transition: 0.25s cubic-bezier(0.25,0.46,0.45,0.94);

  width: 100%;
  max-width: 100%;
  overflow-x: hidden;
  padding: 0 16px 40px;
  box-sizing: border-box;
  font-family: var(--ab-font-body);
  color: var(--ab-text);
  background-color: #0D0D1A;
}

/* 面包屑 */
.page-about .breadcrumb {
  display: flex;
  align-items: center;
  gap: 8px;
  padding: 16px 0 8px;
  font-size: 0.85rem;
  color: var(--ab-muted);
  flex-wrap: wrap;
}
.page-about .breadcrumb a {
  color: var(--ab-gold);
  text-decoration: none;
  transition: opacity var(--ab-transition);
}
.page-about .breadcrumb a:hover,
.page-about .breadcrumb a:focus-visible {
  opacity: 0.75;
  outline: 2px solid var(--ab-gold);
  outline-offset: 2px;
}
.page-about .breadcrumb .sep {
  color: var(--ab-muted);
  user-select: none;
}
.page-about .breadcrumb [aria-current="page"] {
  color: var(--ab-text);
  font-weight: 600;
}

/* ===== 品牌宣言 · 框景首屏 ===== */
.page-about .brand-hero {
  position: relative;
  margin: 0 0 36px;
  padding: 0;
  border: 3px solid var(--ab-border-gold);
  box-shadow: 0 0 0 2px #0D0D1A, 0 0 0 5px var(--ab-border-gold), 0 12px 40px rgba(255,215,0,0.15);
  background: linear-gradient(135deg, rgba(229,57,53,0.12) 0%, rgba(21,101,192,0.12) 100%);
  overflow: hidden;
}
.page-about .brand-hero__inner {
  display: flex;
  flex-direction: column;
  gap: 0;
}
.page-about .brand-hero__image {
  display: block;
  width: 100%;
  max-width: 100%;
  height: auto;
  object-fit: cover;
  aspect-ratio: 800 / 300;
  border-bottom: 2px solid var(--ab-border-gold);
}
.page-about .brand-hero__text {
  padding: 24px 20px 32px;
}
.page-about .brand-hero__heading {
  font-family: var(--ab-font-heading);
  font-size: 2.2rem;
  font-weight: 800;
  font-style: italic;
  letter-spacing: -0.02em;
  margin: 0 0 6px;
  background: linear-gradient(135deg, var(--ab-red), var(--ab-gold), var(--ab-blue));
  -webkit-background-clip: text;
  background-clip: text;
  color: transparent;
  line-height: 1.1;
  text-shadow: none;
}
.page-about .brand-hero__sub {
  font-family: var(--ab-font-heading);
  font-size: 1.15rem;
  font-weight: 600;
  color: var(--ab-gold);
  margin: 0 0 12px;
  text-transform: uppercase;
  letter-spacing: 0.06em;
}
.page-about .brand-hero__desc {
  font-size: 1rem;
  line-height: 1.7;
  color: var(--ab-text);
  max-width: 680px;
  margin: 0;
}

/* ===== 倾斜分割线 ===== */
.page-about .gold-divider.angled {
  position: relative;
  width: 100%;
  height: 6px;
  background: linear-gradient(to right, transparent, var(--ab-gold), transparent);
  transform: skewY(-1.5deg);
  margin: 0;
  border: none;
  opacity: 0.7;
}

/* ===== 发展里程碑 ===== */
.page-about .milestones {
  padding: 32px 0 24px;
}
.page-about .milestones__title {
  font-family: var(--ab-font-heading);
  font-size: 1.9rem;
  font-weight: 800;
  font-style: italic;
  margin: 0 0 8px;
  color: var(--ab-text);
  letter-spacing: -0.01em;
}
.page-about .milestones__intro {
  font-size: 0.95rem;
  color: var(--ab-muted);
  margin: 0 0 28px;
  line-height: 1.6;
  max-width: 560px;
}

/* Bento 网格 — 移动端单列 */
.page-about .milestones__grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: 16px;
}

/* 里程碑卡片 */
.page-about .milestone-card {
  position: relative;
  background: var(--ab-bg-card);
  border: 2px solid rgba(255,215,0,0.25);
  border-radius: var(--ab-radius);
  padding: 20px 18px 18px;
  cursor: default;
  transition: transform var(--ab-transition), border-color var(--ab-transition), box-shadow var(--ab-transition);
  display: flex;
  flex-direction: column;
  gap: 8px;
}
.page-about .milestone-card:hover {
  transform: scale(1.02);
  border-color: var(--ab-gold);
  box-shadow: 0 8px 30px rgba(255,215,0,0.12);
}

/* 卡片标签（版本号 / 批次） */
.page-about .milestone-card__label {
  display: inline-block;
  font-family: var(--ab-font-body);
  font-size: 0.8rem;
  font-weight: 700;
  letter-spacing: 0.08em;
  color: var(--ab-gold);
  background: rgba(255,215,0,0.1);
  border: 1px solid var(--ab-gold);
  padding: 2px 12px;
  border-radius: 20px;
  align-self: flex-start;
}
.page-about .milestone-card__heading {
  font-family: var(--ab-font-heading);
  font-size: 1.3rem;
  font-weight: 700;
  font-style: italic;
  margin: 0;
  color: var(--ab-text);
  line-height: 1.2;
}
.page-about .milestone-card__summary {
  font-size: 0.9rem;
  color: var(--ab-muted);
  margin: 0;
  line-height: 1.5;
}
.page-about .milestone-card__details {
  font-size: 0.9rem;
  color: var(--ab-text);
  margin-top: 4px;
  border-top: 1px solid rgba(255,215,0,0.15);
  padding-top: 8px;
}
.page-about .milestone-card__details summary {
  cursor: pointer;
  font-weight: 600;
  color: var(--ab-gold);
  transition: opacity var(--ab-transition);
  list-style: none;
  display: flex;
  align-items: center;
  gap: 6px;
}
.page-about .milestone-card__details summary::-webkit-details-marker {
  display: none;
}
.page-about .milestone-card__details summary::before {
  content: "▶";
  font-size: 0.7rem;
  transition: transform var(--ab-transition);
  display: inline-block;
}
.page-about .milestone-card__details[open] summary::before {
  transform: rotate(90deg);
}
.page-about .milestone-card__details summary:hover,
.page-about .milestone-card__details summary:focus-visible {
  opacity: 0.8;
  outline: 2px solid var(--ab-gold);
  outline-offset: 2px;
}
.page-about .milestone-card__body {
  padding-top: 8px;
  line-height: 1.6;
  font-size: 0.9rem;
  color: var(--ab-muted);
}

/* 时间轴线（装饰） */
.page-about .timeline-rail {
  display: none;
}

/* ===== 数据能力 ===== */
.page-about .data-capability {
  padding: 24px 0 28px;
}
.page-about .data-capability__title {
  font-family: var(--ab-font-heading);
  font-size: 1.9rem;
  font-weight: 800;
  font-style: italic;
  margin: 0 0 20px;
  color: var(--ab-text);
}
.page-about .data-capability__content {
  display: flex;
  flex-direction: column;
  gap: 20px;
  padding: 20px;
  border: 3px solid var(--ab-border-gold);
  box-shadow: 0 0 0 2px #0D0D1A, 0 0 0 5px var(--ab-border-gold), 0 8px 30px rgba(255,215,0,0.08);
}
.page-about .data-capability__visual {
  flex-shrink: 0;
}
.page-about .data-capability__image {
  display: block;
  width: 100%;
  max-width: 100%;
  height: auto;
  object-fit: cover;
  aspect-ratio: 400 / 300;
  border: 1px solid rgba(255,215,0,0.3);
  border-radius: 6px;
}
.page-about .data-capability__text {
  display: flex;
  flex-direction: column;
  gap: 16px;
}
.page-about .data-capability__lead {
  font-size: 1.05rem;
  font-weight: 600;
  line-height: 1.7;
  margin: 0;
  color: var(--ab-text);
}
.page-about .data-capability__list {
  list-style: none;
  margin: 0;
  padding: 0;
  display: flex;
  flex-direction: column;
  gap: 12px;
}
.page-about .data-capability__item {
  display: flex;
  align-items: flex-start;
  gap: 12px;
  font-size: 0.95rem;
  line-height: 1.6;
  color: var(--ab-text);
}
.page-about .data-capability__item .mono-index {
  flex-shrink: 0;
  font-family: var(--ab-font-body);
  font-size: 0.85rem;
  font-weight: 700;
  color: var(--ab-gold);
  background: rgba(255,215,0,0.08);
  border: 1px solid var(--ab-gold);
  border-radius: 4px;
  padding: 0 8px;
  line-height: 1.8;
}

/* ===== 品牌理念深化 ===== */
.page-about .brand-philosophy {
  padding: 28px 0 20px;
}
.page-about .brand-philosophy__inner {
  max-width: 900px;
}
.page-about .brand-philosophy__title {
  font-family: var(--ab-font-heading);
  font-size: 1.9rem;
  font-weight: 800;
  font-style: italic;
  margin: 0 0 24px;
  color: var(--ab-gold);
  text-align: center;
}
.page-about .brand-philosophy__grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: 16px;
}
.page-about .brand-philosophy__block {
  padding: 20px 18px;
  border-radius: var(--ab-radius);
  border: 2px solid rgba(255,215,0,0.15);
  display: flex;
  flex-direction: column;
  gap: 6px;
  transition: transform var(--ab-transition), border-color var(--ab-transition);
}
.page-about .brand-philosophy__block:hover {
  transform: scale(1.02);
  border-color: var(--ab-gold);
}
.page-about .brand-philosophy__block .mono-index {
  font-family: var(--ab-font-body);
  font-size: 0.85rem;
  font-weight: 700;
  color: var(--ab-gold);
  opacity: 0.7;
}
.page-about .brand-philosophy__block h3 {
  font-family: var(--ab-font-heading);
  font-size: 1.3rem;
  font-weight: 700;
  font-style: italic;
  margin: 0;
  color: var(--ab-text);
}
.page-about .brand-philosophy__block p {
  font-size: 0.95rem;
  line-height: 1.6;
  margin: 0;
  color: var(--ab-muted);
}
.page-about .brand-philosophy__block--red {
  border-left-color: var(--ab-red);
  background: linear-gradient(135deg, rgba(229,57,53,0.06), transparent);
}
.page-about .brand-philosophy__block--blue {
  border-left-color: var(--ab-blue);
  background: linear-gradient(135deg, rgba(21,101,192,0.06), transparent);
}
.page-about .brand-philosophy__block--gold {
  border-left-color: var(--ab-gold);
  background: linear-gradient(135deg, rgba(255,215,0,0.06), transparent);
}

/* ===== 内部链接 ===== */
.page-about .internal-links {
  padding: 28px 0 16px;
}
.page-about .internal-links__title {
  font-family: var(--ab-font-heading);
  font-size: 1.4rem;
  font-weight: 700;
  font-style: italic;
  margin: 0 0 16px;
  color: var(--ab-text);
}
.page-about .internal-links__list {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
}
.page-about .internal-links__item {
  text-decoration: none;
  color: var(--ab-text);
  border: 2px solid var(--ab-gold);
  padding: 10px 22px;
  border-radius: 40px;
  font-weight: 600;
  font-size: 0.95rem;
  transition: background var(--ab-transition), color var(--ab-transition), transform var(--ab-transition);
  background: transparent;
}
.page-about .internal-links__item:hover,
.page-about .internal-links__item:focus-visible {
  background: var(--ab-gold);
  color: #0D0D1A;
  transform: scale(1.04);
  outline: none;
}

/* ===== 底部标语条 ===== */
.page-about .brand-tagline-bar {
  margin-top: 32px;
  padding: 14px 0;
  border-top: 2px solid rgba(255,215,0,0.2);
  border-bottom: 2px solid rgba(255,215,0,0.2);
  text-align: center;
}
.page-about .brand-tagline-bar__text {
  font-family: var(--ab-font-heading);
  font-size: 1.2rem;
  font-weight: 700;
  font-style: italic;
  color: var(--ab-gold);
  letter-spacing: 0.04em;
  background: linear-gradient(135deg, var(--ab-red), var(--ab-gold), var(--ab-blue));
  -webkit-background-clip: text;
  background-clip: text;
  color: transparent;
}

/* ===== 响应式增强：平板 / 桌面 ===== */
@media (min-width: 640px) {
  .page-about {
    padding: 0 32px 48px;
  }
  .page-about .brand-hero__text {
    padding: 32px 36px 40px;
  }
  .page-about .brand-hero__heading {
    font-size: 3rem;
  }
  .page-about .brand-hero__sub {
    font-size: 1.35rem;
  }
  .page-about .brand-hero__desc {
    font-size: 1.05rem;
  }
  .page-about .milestones__grid {
    grid-template-columns: repeat(2, 1fr);
    gap: 18px;
  }
  .page-about .milestone-card--large {
    grid-column: 1 / -1;
  }
  .page-about .data-capability__content {
    flex-direction: row;
    align-items: flex-start;
  }
  .page-about .data-capability__visual {
    flex: 0 0 220px;
  }
  .page-about .brand-philosophy__grid {
    grid-template-columns: repeat(3, 1fr);
    gap: 20px;
  }
}

@media (min-width: 1024px) {
  .page-about {
    padding: 0 48px 60px;
    max-width: 1200px;
    margin: 0 auto;
  }
  .page-about .milestones__grid {
    grid-template-columns: repeat(3, 1fr);
    gap: 20px;
  }
  .page-about .milestone-card--large {
    grid-column: 1 / 3;
    grid-row: 1 / 3;
  }
  .page-about .milestone-card--medium {
    /* 自然占位 */
  }
  .page-about .milestone-card--small {
    /* 自然占位 */
  }
  .page-about .milestones__grid {
    grid-auto-rows: minmax(auto, 1fr);
  }

  /* 时间轴线（桌面显示） */
  .page-about .timeline-rail {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 12px 0 0;
    margin-top: 8px;
    position: relative;
  }
  .page-about .timeline-rail::before {
    content: "";
    position: absolute;
    top: 50%;
    left: 0;
    right: 0;
    height: 2px;
    background: linear-gradient(to right, transparent, var(--ab-gold), transparent);
    transform: translateY(-50%);
    opacity: 0.3;
  }
  .page-about .timeline-rail__dot {
    width: 12px;
    height: 12px;
    border-radius: 50%;
    background: var(--ab-gold);
    border: 2px solid #0D0D1A;
    box-shadow: 0 0 0 2px var(--ab-gold);
    position: relative;
    z-index: 1;
  }
  .page-about .data-capability__visual {
    flex: 0 0 280px;
  }
  .page-about .brand-hero__heading {
    font-size: 3.6rem;
  }
}