/* =========================================================
   page-about 专属样式
   作用域限定 .page-about，避免污染共享组件
   移动端优先 + 桌面媒体查询
   ========================================================= */

/* ---------- 变量定义 ---------- */
.page-about {
  --ab-glow: rgba(230, 57, 70, 0.3);
  --ab-gold-fade: rgba(244, 162, 97, 0.25);
  --ab-timeline-width: 4px;
  --ab-dot-size: 20px;
  --ab-card-radius: 0;
}

/* ---------- 品牌理念（首屏） ---------- */
.page-about .brand-mission {
  position: relative;
  overflow: hidden;
  background-color: var(--deep-blue);
}

.page-about .brand-mission .panel-inner {
  padding-top: calc(var(--panel-pad) * 0.6);
  padding-bottom: var(--panel-pad);
}

.page-about .breadcrumb {
  display: flex;
  align-items: center;
  gap: 0.4rem;
  font-family: var(--font-body);
  font-size: 0.8rem;
  color: var(--gray);
  margin-bottom: 1.5rem;
}

.page-about .breadcrumb a {
  color: var(--gold);
  text-decoration: none;
  transition: color var(--transition);
}

.page-about .breadcrumb a:hover,
.page-about .breadcrumb a:focus-visible {
  color: var(--red);
}

.page-about .breadcrumb .sep {
  color: var(--border);
}

.page-about .mission-grid {
  display: flex;
  flex-direction: column;
  gap: 2rem;
}

.page-about .mission-text-block {
  position: relative;
  z-index: 2;
}

.page-about .mission-text-block .tag-label {
  display: inline-block;
  margin-bottom: 0.75rem;
}

.page-about .mission-title {
  font-family: var(--font-heading);
  font-weight: 900;
  font-size: clamp(2.2rem, 8vw, 4.5rem);
  line-height: 1.05;
  text-transform: uppercase;
  color: var(--white);
  letter-spacing: 0.04em;
  margin: 0 0 1rem 0;
}

.page-about .mission-quote {
  font-family: var(--font-body);
  font-size: clamp(1rem, 3vw, 1.35rem);
  font-weight: 300;
  font-style: italic;
  color: var(--gold);
  border-left: 3px solid var(--red);
  padding-left: 1.2rem;
  margin: 0 0 1.2rem 0;
  line-height: 1.5;
}

.page-about .mission-desc {
  font-family: var(--font-body);
  font-size: 1rem;
  line-height: 1.7;
  color: var(--gray);
  max-width: 580px;
  margin-bottom: 1.8rem;
}

.page-about .mission-actions {
  display: flex;
  flex-wrap: wrap;
  gap: 0.8rem;
}

.page-about .mission-actions .btn-primary {
  background-color: var(--red);
  color: var(--white);
  padding: 0.7rem 1.8rem;
  font-family: var(--font-body);
  font-weight: 700;
  text-transform: uppercase;
  text-decoration: none;
  letter-spacing: 0.04em;
  transition: background-color var(--transition), transform var(--transition);
  border: none;
  cursor: pointer;
}

.page-about .mission-actions .btn-primary:hover,
.page-about .mission-actions .btn-primary:focus-visible {
  background-color: #c4303c;
  transform: translateY(-2px);
}

.page-about .mission-actions .btn-ghost {
  background: transparent;
  color: var(--gold);
  padding: 0.7rem 1.8rem;
  font-family: var(--font-body);
  font-weight: 600;
  text-decoration: none;
  border: 1px solid var(--gold);
  transition: background-color var(--transition), color var(--transition);
  cursor: pointer;
}

.page-about .mission-actions .btn-ghost:hover,
.page-about .mission-actions .btn-ghost:focus-visible {
  background-color: var(--gold);
  color: var(--deep-blue);
}

.page-about .mission-visual {
  position: relative;
  z-index: 1;
  width: 100%;
}

.page-about .mission-hero-img {
  width: 100%;
  height: auto;
  max-width: 100%;
  object-fit: cover;
  border: 1px solid var(--border);
  opacity: 0.9;
}

/* ---------- 发展里程碑 ---------- */
.page-about .milestones {
  background-color: var(--light-bg);
}

.page-about .milestones .section-title {
  font-family: var(--font-heading);
  font-weight: 900;
  font-size: clamp(1.8rem, 5vw, 3rem);
  text-transform: uppercase;
  color: var(--text-dark);
  margin: 0 0 0.3rem 0;
  letter-spacing: 0.04em;
}

.page-about .milestones .section-sub {
  font-family: var(--font-body);
  font-size: 1rem;
  color: #555;
  margin: 0 0 2.5rem 0;
  max-width: 500px;
}

/* ---- 时间线容器 ---- */
.page-about .timeline {
  position: relative;
  padding-left: 2.5rem;
}

/* 竖线 — 移动端在左侧 */
.page-about .timeline-rail {
  position: absolute;
  top: 0;
  bottom: 0;
  left: 0.8rem;
  width: var(--ab-timeline-width);
  background: linear-gradient(180deg, var(--red) 0%, var(--deep-blue) 100%);
  border-radius: 2px;
  z-index: 0;
}

/* 每个节点 */
.page-about .timeline-node {
  position: relative;
  display: flex;
  gap: 1.2rem;
  margin-bottom: 2.5rem;
  z-index: 1;
}

.page-about .timeline-node:last-child {
  margin-bottom: 0;
}

/* 圆点标记 */
.page-about .node-marker {
  flex-shrink: 0;
  width: var(--ab-dot-size);
  height: var(--ab-dot-size);
  position: relative;
  z-index: 2;
  display: flex;
  align-items: center;
  justify-content: center;
}

.page-about .node-dot {
  display: block;
  width: 14px;
  height: 14px;
  border-radius: 50%;
  background-color: var(--gold);
  border: 3px solid var(--deep-blue);
  box-shadow: 0 0 0 2px var(--gold);
  transition: transform var(--transition), box-shadow var(--transition);
}

.page-about .timeline-node:hover .node-dot,
.page-about .timeline-node:focus-within .node-dot {
  transform: scale(1.25);
  box-shadow: 0 0 0 4px var(--gold), 0 0 20px var(--ab-gold-fade);
}

/* 卡片 */
.page-about .node-card {
  flex: 1;
  background-color: var(--white);
  padding: 1rem 1.2rem;
  border: 1px solid var(--border);
  transition: box-shadow var(--transition);
  min-width: 0;
}

.page-about .node-card:hover,
.page-about .node-card:focus-within {
  box-shadow: 4px 4px 0 var(--ab-glow);
}

.page-about .node-phase {
  display: inline-block;
  font-family: var(--font-data);
  font-size: 0.75rem;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 0.08em;
  color: var(--red);
  margin-bottom: 0.3rem;
}

.page-about .node-title {
  font-family: var(--font-heading);
  font-weight: 900;
  font-size: 1.2rem;
  text-transform: uppercase;
  color: var(--text-dark);
  margin: 0 0 0.4rem 0;
  letter-spacing: 0.03em;
}

.page-about .node-summary {
  font-family: var(--font-body);
  font-size: 0.95rem;
  line-height: 1.5;
  color: #333;
  margin: 0 0 0.6rem 0;
}

/* details 展开 */
.page-about .node-details {
  font-family: var(--font-body);
  font-size: 0.9rem;
}

.page-about .node-details summary {
  cursor: pointer;
  color: var(--red);
  font-weight: 700;
  font-size: 0.85rem;
  text-transform: uppercase;
  letter-spacing: 0.04em;
  padding: 0.2rem 0;
  transition: color var(--transition);
  user-select: none;
}

.page-about .node-details summary:hover,
.page-about .node-details summary:focus-visible {
  color: #c4303c;
}

.page-about .details-body {
  padding-top: 0.6rem;
  border-top: 1px solid var(--border);
  margin-top: 0.4rem;
}

.page-about .details-body p {
  font-size: 0.9rem;
  line-height: 1.6;
  color: #444;
  margin: 0 0 0.6rem 0;
}

.page-about .btn-compact {
  display: inline-block;
  font-family: var(--font-body);
  font-size: 0.8rem;
  font-weight: 700;
  text-transform: uppercase;
  color: var(--deep-blue);
  text-decoration: none;
  border-bottom: 2px solid var(--gold);
  padding-bottom: 0.1rem;
  transition: color var(--transition), border-color var(--transition);
}

.page-about .btn-compact:hover,
.page-about .btn-compact:focus-visible {
  color: var(--red);
  border-bottom-color: var(--red);
}

/* 带图片的节点卡片 */
.page-about .node-card-img {
  padding: 0.5rem;
  background: var(--white);
}

.page-about .node-card-img img {
  width: 100%;
  height: auto;
  max-width: 100%;
  display: block;
  object-fit: cover;
  border: 1px solid var(--border);
}

.page-about .node-card-caption {
  font-family: var(--font-body);
  font-size: 0.75rem;
  color: #666;
  text-align: center;
  padding: 0.4rem 0 0.1rem 0;
  letter-spacing: 0.03em;
}

/* ---------- 技术优势 ---------- */
.page-about .tech-advantages {
  background-color: var(--deep-blue);
}

.page-about .tech-advantages .section-title {
  font-family: var(--font-heading);
  font-weight: 900;
  font-size: clamp(1.8rem, 5vw, 3rem);
  text-transform: uppercase;
  color: var(--white);
  margin: 0 0 0.3rem 0;
  letter-spacing: 0.04em;
}

.page-about .tech-advantages .section-sub {
  font-family: var(--font-body);
  font-size: 1rem;
  color: var(--gray);
  margin: 0 0 2.5rem 0;
  max-width: 550px;
}

/* 卡片网格 */
.page-about .tech-grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: 1.5rem;
  margin-bottom: 2.5rem;
}

.page-about .tech-card {
  position: relative;
  background-color: rgba(255, 255, 255, 0.06);
  border: 1px solid var(--border);
  padding: 1.5rem 1.2rem 1.2rem;
  transition: background-color var(--transition), border-color var(--transition), transform var(--transition);
  cursor: default;
}

.page-about .tech-card:hover,
.page-about .tech-card:focus-within {
  background-color: rgba(255, 255, 255, 0.1);
  border-color: var(--gold);
  transform: translateY(-3px);
}

.page-about .tech-step {
  font-family: var(--font-heading);
  font-size: 2rem;
  font-weight: 900;
  color: var(--red);
  line-height: 1;
  margin-bottom: 0.3rem;
  opacity: 0.7;
}

.page-about .tech-title {
  font-family: var(--font-heading);
  font-weight: 900;
  font-size: 1.15rem;
  text-transform: uppercase;
  color: var(--white);
  margin: 0 0 0.5rem 0;
  letter-spacing: 0.04em;
}

.page-about .tech-desc {
  font-family: var(--font-body);
  font-size: 0.95rem;
  line-height: 1.5;
  color: var(--gray);
  margin: 0 0 0.8rem 0;
}

/* 悬停揭示 */
.page-about .tech-hover-reveal {
  max-height: 0;
  overflow: hidden;
  opacity: 0;
  transition: max-height 0.35s ease, opacity 0.35s ease, margin 0.35s ease;
  margin-top: 0;
}

.page-about .tech-card:hover .tech-hover-reveal,
.page-about .tech-card:focus-within .tech-hover-reveal {
  max-height: 200px;
  opacity: 1;
  margin-top: 0.8rem;
}

.page-about .tech-hover-reveal .tag-label {
  display: inline-block;
  font-size: 0.7rem;
  margin-bottom: 0.3rem;
  color: var(--gold);
  border-bottom: 2px solid var(--gold);
  padding-bottom: 0.15rem;
  text-transform: uppercase;
  letter-spacing: 0.06em;
}

.page-about .tech-hover-reveal p {
  font-family: var(--font-body);
  font-size: 0.85rem;
  color: var(--gray);
  line-height: 1.5;
  margin: 0;
}

/* 流程示意图 */
.page-about .tech-figure {
  margin: 2rem 0 1.5rem;
  text-align: center;
}

.page-about .tech-figure img {
  width: 100%;
  max-width: 500px;
  height: auto;
  object-fit: contain;
  border: 1px solid var(--border);
  background-color: rgba(255, 255, 255, 0.04);
  padding: 0.5rem;
}

.page-about .tech-figcaption {
  font-family: var(--font-body);
  font-size: 0.8rem;
  color: var(--gray);
  margin-top: 0.4rem;
  letter-spacing: 0.03em;
}

/* 底部 CTA */
.page-about .tech-cta {
  border-top: 1px solid var(--border);
  padding-top: 1.8rem;
  margin-top: 1rem;
  text-align: center;
}

.page-about .tech-cta p {
  font-family: var(--font-body);
  font-size: 0.95rem;
  color: var(--gray);
  max-width: 600px;
  margin: 0 auto 1.2rem;
  line-height: 1.6;
}

.page-about .tech-cta .btn-accent {
  display: inline-block;
  background-color: var(--gold);
  color: var(--deep-blue);
  padding: 0.7rem 2.2rem;
  font-family: var(--font-body);
  font-weight: 700;
  text-transform: uppercase;
  text-decoration: none;
  letter-spacing: 0.05em;
  transition: background-color var(--transition), transform var(--transition);
  border: none;
  cursor: pointer;
}

.page-about .tech-cta .btn-accent:hover,
.page-about .tech-cta .btn-accent:focus-visible {
  background-color: #e08f4f;
  transform: translateY(-2px);
}

/* ---------- 共享 class 微调 ---------- */
.page-about .tag-label.gold {
  color: var(--gold);
  border-bottom: 2px solid var(--gold);
  padding-bottom: 0.2rem;
  text-transform: uppercase;
  font-family: var(--font-body);
  font-weight: 700;
  font-size: 0.75rem;
  letter-spacing: 0.08em;
}

.page-about .panel-inner {
  width: 100%;
  max-width: var(--content-max);
  margin: 0 auto;
  padding-left: 1.2rem;
  padding-right: 1.2rem;
}

/* ---------- 桌面媒体查询 (min-width: 768px) ---------- */
@media (min-width: 768px) {

  /* ---- 品牌理念 ---- */
  .page-about .brand-mission .panel-inner {
    padding-top: var(--panel-pad);
    padding-bottom: var(--panel-pad);
  }

  .page-about .mission-grid {
    flex-direction: row;
    align-items: center;
    gap: 3rem;
  }

  .page-about .mission-text-block {
    flex: 1 1 55%;
  }

  .page-about .mission-visual {
    flex: 1 1 40%;
    margin-top: 0;
  }

  .page-about .mission-hero-img {
    max-width: 100%;
    height: auto;
  }

  .page-about .mission-title {
    font-size: clamp(3rem, 5vw, 4.5rem);
  }

  /* ---- 时间线 桌面端 ---- */
  .page-about .timeline {
    padding-left: 0;
    padding-right: 0;
  }

  .page-about .timeline-rail {
    left: 50%;
    transform: translateX(-50%);
    width: var(--ab-timeline-width);
  }

  .page-about .timeline-node {
    justify-content: flex-start;
    gap: 1.5rem;
    margin-bottom: 3rem;
  }

  /* 交替布局：偶数节点在右，奇数节点在左 */
  .page-about .timeline-node:nth-child(odd) {
    flex-direction: row;
    padding-right: calc(50% + 1.5rem);
  }

  .page-about .timeline-node:nth-child(even) {
    flex-direction: row-reverse;
    padding-left: calc(50% + 1.5rem);
    text-align: right;
  }

  .page-about .timeline-node:nth-child(even) .node-card {
    text-align: left;
  }

  .page-about .timeline-node:nth-child(even) .node-details summary {
    text-align: left;
  }

  /* 圆点保持在竖线上 */
  .page-about .node-marker {
    flex-shrink: 0;
    position: relative;
    z-index: 3;
  }

  .page-about .node-dot {
    width: 18px;
    height: 18px;
  }

  .page-about .node-card {
    max-width: 420px;
    padding: 1.2rem 1.5rem;
  }

  .page-about .node-card-img {
    padding: 0.5rem;
  }

  .page-about .node-title {
    font-size: 1.3rem;
  }

  /* ---- 技术优势 ---- */
  .page-about .tech-grid {
    grid-template-columns: repeat(3, 1fr);
    gap: 2rem;
  }

  .page-about .tech-card {
    padding: 2rem 1.5rem 1.5rem;
  }

  .page-about .tech-step {
    font-size: 2.4rem;
  }

  .page-about .tech-figure img {
    max-width: 100%;
  }

  .page-about .panel-inner {
    padding-left: 2rem;
    padding-right: 2rem;
  }
}

/* ---------- 大桌面微调 (min-width: 1024px) ---------- */
@media (min-width: 1024px) {
  .page-about .mission-grid {
    gap: 4rem;
  }

  .page-about .mission-text-block {
    flex: 1 1 50%;
  }

  .page-about .mission-visual {
    flex: 1 1 45%;
  }

  .page-about .timeline-node:nth-child(odd) {
    padding-right: calc(50% + 2.5rem);
  }

  .page-about .timeline-node:nth-child(even) {
    padding-left: calc(50% + 2.5rem);
  }

  .page-about .node-card {
    max-width: 480px;
    padding: 1.5rem 2rem;
  }
}