.page-about{
  --about-accent: #33ff99;
  --about-accent-dim: rgba(51,255,153,0.6);
  --about-orange: #ff8c42;
  --about-line: rgba(230,237,243,0.15);
  --about-bg-elevated: #10182b;
  --about-bg-card: #1a2438;
  --about-text: #e6edf3;
  --about-text-muted: #9aa7b8;
  --about-font-sans: 'Rajdhani', 'Noto Sans SC', 'PingFang SC', 'Microsoft YaHei', sans-serif;
  --about-font-serif: 'Noto Serif SC', 'Songti SC', STSong, 'SimSun', serif;
  position: relative;
  background:
    linear-gradient(90deg, transparent 24px, rgba(230,237,243,0.04) 25px, transparent 26px) 0 0 / 60px 60px,
    linear-gradient(0deg, transparent 24px, rgba(230,237,243,0.04) 25px, transparent 26px) 0 0 / 60px 60px,
    var(--color-bg);
}

/* ===== 英雄区 ===== */
.about-hero{
  padding: 3.5rem 0 4rem;
  position: relative;
}

.about-hero::before{
  content: "";
  position: absolute;
  top: 0;
  right: 0;
  width: 64%;
  height: 1px;
  background: linear-gradient(90deg, transparent, var(--about-accent-dim), transparent);
}

.about-hero-grid{
  display: grid;
  gap: 2.5rem;
  margin-top: 2rem;
}

.about-hero-copy .section-label{
  color: var(--about-accent);
  letter-spacing: 0.12em;
  text-transform: uppercase;
  font-family: var(--about-font-sans);
  font-size: 0.875rem;
  font-weight: 700;
  margin-bottom: 1rem;
  display: inline-block;
  border-left: 2px solid var(--about-accent);
  padding-left: 0.6rem;
}

.about-hero-copy h1{
  font-family: var(--about-font-sans);
  font-size: clamp(2rem, 6vw, 3.25rem);
  font-weight: 700;
  line-height: 1.1;
  color: var(--about-text);
  letter-spacing: 0.01em;
  margin: 0 0 1rem 0;
  text-transform: uppercase;
  max-width: 11em;
}

.about-lead{
  font-family: var(--about-font-serif);
  font-size: 1rem;
  line-height: 1.8;
  color: var(--about-text-muted);
  max-width: 32em;
  margin: 0 0 1.5rem;
}

.about-hero-actions{
  display: flex;
  flex-wrap: wrap;
  gap: 0.75rem;
}

.about-hero-board{
  border: 1px solid var(--about-line);
  background: rgba(16, 24, 43, 0.6);
  padding: 1.5rem 1.25rem;
  position: relative;
  clip-path: polygon(0 0, calc(100% - 12px) 0, 100% 12px, 100% 100%, 12px 100%, 0 calc(100% - 12px));
}

.about-hero-board::after{
  content: "BA";
  position: absolute;
  right: 8px;
  bottom: 4px;
  font-family: var(--about-font-sans);
  font-size: 2.25rem;
  font-weight: 700;
  color: rgba(51, 255, 153, 0.16);
  letter-spacing: -0.03em;
  pointer-events: none;
}

.board-caption{
  font-family: var(--about-font-sans);
  font-size: 0.75rem;
  letter-spacing: 0.22em;
  color: var(--about-text-muted);
  text-transform: uppercase;
  margin: 0 0 1rem 0;
  border-bottom: 1px solid var(--about-line);
  padding-bottom: 0.5rem;
}

.about-index-list{
  list-style: none;
  margin: 0;
  padding: 0;
}

.about-index-list li + li{
  margin-top: 0.4rem;
}

.about-index-list a{
  display: flex;
  align-items: center;
  gap: 0.6rem;
  font-family: var(--about-font-sans);
  font-size: 0.95rem;
  font-weight: 500;
  color: var(--about-text);
  text-decoration: none;
  padding: 0.25rem 0;
  border-bottom: 1px solid transparent;
  transition: border-color 0.3s cubic-bezier(0.22, 1, 0.36, 1), color 0.3s;
}

.about-index-list a:hover{
  color: var(--about-accent);
  border-bottom-color: var(--about-accent-dim);
}

.index-num{
  font-size: 0.72rem;
  color: var(--about-accent);
  font-family: var(--about-font-sans);
  letter-spacing: 0.08em;
  background: rgba(51, 255, 153, 0.08);
  padding: 0.12rem 0.35rem;
}

/* ===== 品牌故事 ===== */
.about-story-section{
  padding: 2.5rem 0 4rem;
}

.about-story-wrap{
  display: grid;
  gap: 2rem;
}

.story-copy .section-label{
  color: var(--about-accent);
  letter-spacing: 0.12em;
  text-transform: uppercase;
  font-family: var(--about-font-sans);
  font-size: 0.875rem;
  font-weight: 700;
  margin-bottom: 1rem;
  display: inline-block;
  border-left: 2px solid var(--about-accent);
  padding-left: 0.6rem;
}

.story-copy h2,
.section-heading-row h2,
.tech-copy h2,
.eco-intro h2,
.about-cert-section .section-heading-row h2{
  font-family: var(--about-font-sans);
  font-size: clamp(1.5rem, 4vw, 2.25rem);
  font-weight: 700;
  line-height: 1.25;
  color: var(--about-text);
  margin: 0 0 1rem 0;
  text-transform: uppercase;
}

.story-copy > p:not(.section-label):not(.story-quote){
  font-family: var(--about-font-serif);
  font-size: 0.925rem;
  line-height: 1.8;
  color: var(--about-text-muted);
  margin: 0 0 1rem;
}

.story-quote{
  font-family: var(--about-font-serif);
  font-size: 0.925rem;
  line-height: 1.8;
  color: var(--about-text);
  border-left: 2px solid var(--about-orange);
  padding-left: 1rem;
  margin: 1.25rem 0;
  background: rgba(255, 140, 66, 0.04);
  padding: 0.9rem 1rem 0.9rem 1.4rem;
}

.story-inline-img{
  display: block;
  width: 100%;
  max-width: 100%;
  height: auto;
  margin-top: 1.5rem;
  object-fit: cover;
  filter: grayscale(0.2) contrast(1.05);
}

.story-side-info{
  display: flex;
  flex-direction: column;
  gap: 1rem;
}

.side-info-title{
  font-family: var(--about-font-sans);
  font-size: 0.8rem;
  letter-spacing: 0.2em;
  text-transform: uppercase;
  color: var(--about-accent);
  margin: 0 0 0.75rem;
  border-bottom: 1px solid var(--about-line);
  padding-bottom: 0.4rem;
}

.side-info-item{
  display: flex;
  justify-content: space-between;
  align-items: baseline;
  padding: 0.35rem 0;
  border-bottom: 1px dashed rgba(230, 237, 243, 0.08);
}

.side-info-item:last-of-type{
  border-bottom: none;
}

.side-info-label{
  font-family: var(--about-font-sans);
  font-size: 0.8rem;
  color: var(--about-text-muted);
  text-transform: uppercase;
  letter-spacing: 0.1em;
}

.side-info-value{
  font-family: var(--about-font-sans);
  font-size: 1.15rem;
  font-weight: 700;
  color: var(--about-text);
}

.side-note{
  font-family: var(--about-font-serif);
  font-size: 0.8rem;
  line-height: 1.7;
  margin: 0;
  color: var(--about-text-muted);
}

/* ===== 时间轴 ===== */
.about-timeline-section{
  padding: 4rem 0;
  background: rgba(16, 24, 43, 0.35);
  border-top: 1px solid var(--about-line);
  border-bottom: 1px solid var(--about-line);
}

.section-heading-row{
  display: grid;
  gap: 0.5rem;
  margin-bottom: 2.5rem;
}

.section-label{
  color: var(--about-accent);
  letter-spacing: 0.12em;
  text-transform: uppercase;
  font-family: var(--about-font-sans);
  font-size: 0.875rem;
  font-weight: 700;
  display: inline-block;
  border-left: 2px solid var(--about-accent);
  padding-left: 0.6rem;
}

.section-note{
  font-family: var(--about-font-serif);
  font-size: 0.875rem;
  line-height: 1.8;
  color: var(--about-text-muted);
  margin: 0;
  max-width: 28em;
}

.about-timeline{
  position: relative;
  margin-top: 2rem;
}

.about-timeline::before{
  content: "";
  position: absolute;
  left: 8px;
  top: 0;
  bottom: 0;
  width: 2px;
  background: linear-gradient(180deg, var(--about-accent), var(--about-line), transparent);
  opacity: 0.7;
}

.timeline-item{
  position: relative;
  padding-left: 2.5rem;
  padding-bottom: 2.25rem;
}

.timeline-item:last-child{
  padding-bottom: 0;
}

.timeline-marker{
  position: absolute;
  left: 2px;
  top: 0.15rem;
  width: 16px;
  height: 16px;
  border-radius: 50%;
  background: var(--color-bg);
  border: 2px solid var(--about-accent);
}

.timeline-marker span{
  position: absolute;
  top: 50%;
  left: 50%;
  transform: translate(-50%, -50%);
  width: 6px;
  height: 6px;
  border-radius: 50%;
  background: var(--about-accent);
}

.timeline-card{
  background: var(--color-bg-card);
  border: 1px solid var(--about-line);
  padding: 1rem 1.25rem;
  clip-path: polygon(0 0, calc(100% - 10px) 0, 100% 10px, 100% 100%, 0 100%);
  transition: transform 0.3s cubic-bezier(0.22, 1, 0.36, 1), border-color 0.3s ease;
}

.timeline-card:hover{
  transform: translateX(4px);
  border-color: rgba(51, 255, 153, 0.4);
}

.timeline-year{
  font-family: var(--about-font-sans);
  font-size: 0.8rem;
  font-weight: 700;
  letter-spacing: 0.1em;
  color: var(--about-accent);
  text-transform: uppercase;
  margin: 0 0 0.3rem;
}

.timeline-card h3{
  font-family: var(--about-font-sans);
  font-size: 1rem;
  font-weight: 600;
  color: var(--about-text);
  margin: 0 0 0.5rem;
}

.timeline-card p:last-child{
  font-family: var(--about-font-serif);
  font-size: 0.85rem;
  line-height: 1.75;
  color: var(--about-text-muted);
  margin: 0;
}

/* ===== 数据覆盖 ===== */
.about-coverage-section{
  padding: 4rem 0;
}

.coverage-hero{
  display: grid;
  gap: 2rem;
  margin-top: 1rem;
}

.coverage-stats{
  display: grid;
  gap: 0.75rem;
  grid-template-columns: repeat(2, 1fr);
}

.coverage-stat-card{
  display: flex;
  flex-direction: column;
  align-items: flex-start;
  justify-content: center;
  background: var(--color-bg-card);
  border: 1px solid var(--about-line);
  padding: 1.25rem 1rem;
  clip-path: polygon(0 0, calc(100% - 10px) 0, 100% 10px, 100% 100%, 10px 100%, 0 calc(100% - 10px));
  transition: transform 0.3s cubic-bezier(0.22, 1, 0.36, 1), border-color 0.3s;
}

.coverage-stat-card:hover{
  transform: translateY(-3px);
  border-color: rgba(51, 255, 153, 0.5);
}

.coverage-stat-card--warm{
  background: rgba(255, 140, 66, 0.08);
  border-color: rgba(255, 140, 66, 0.3);
}

.coverage-stat-card--warm:hover{
  border-color: rgba(255, 140, 66, 0.6);
}

.coverage-stat-card .stat-value{
  font-family: var(--about-font-sans);
  font-size: 2.2rem;
  font-weight: 700;
  line-height: 1;
  color: var(--about-text);
  letter-spacing: 0.02em;
  display: block;
  margin-bottom: 0.5rem;
}

.coverage-stat-card.coverage-stat-card--warm .stat-value{
  color: var(--about-orange);
}

.coverage-stat-card .stat-label{
  font-family: var(--about-font-sans);
  font-size: 0.72rem;
  letter-spacing: 0.12em;
  text-transform: uppercase;
  color: var(--about-text-muted);
  display: block;
}

.coverage-map-img{
  display: block;
  width: 100%;
  max-width: 100%;
  height: auto;
  object-fit: cover;
  clip-path: polygon(0 0, calc(100% - 16px) 0, 100% 16px, 100% 100%, 16px 100%, 0 calc(100% - 16px));
  filter: saturate(0.9) contrast(1.02);
}

.visual-caption{
  margin: 0.75rem 0 0;
  font-family: var(--about-font-serif);
  font-size: 0.8rem;
  line-height: 1.6;
}

/* ===== 技术架构 ===== */
.about-tech-section{
  padding: 4rem 0;
  background:
    linear-gradient(135deg, rgba(51, 255, 153, 0.04) 0%, transparent 50%),
    var(--color-bg);
  border-top: 1px solid var(--about-line);
  border-bottom: 1px solid var(--about-line);
}

.about-tech-grid{
  display: grid;
  gap: 2rem;
}

.tech-copy .section-label{
  color: var(--about-accent);
  letter-spacing: 0.12em;
  text-transform: uppercase;
  font-family: var(--about-font-sans);
  font-size: 0.875rem;
  font-weight: 700;
  margin-bottom: 1rem;
  display: inline-block;
  border-left: 2px solid var(--about-accent);
  padding-left: 0.6rem;
}

.tech-copy > p:not(.section-label){
  font-family: var(--about-font-serif);
  font-size: 0.9rem;
  line-height: 1.8;
  color: var(--about-text-muted);
  margin: 0 0 1.5rem;
}

.tech-points-list{
  list-style: none;
  margin: 0;
  padding: 0;
  display: grid;
  gap: 1rem;
}

.tech-points-list li{
  display: grid;
  grid-template-columns: 2.2rem 1fr;
  gap: 0.8rem;
  align-items: flex-start;
  padding: 0.9rem;
  background: rgba(26, 36, 56, 0.5);
  border: 1px solid var(--about-line);
  transition: border-color 0.3s ease;
}

.tech-points-list li:hover{
  border-color: rgba(51, 255, 153, 0.5);
}

.tech-point-icon{
  font-family: var(--about-font-sans);
  font-size: 0.8rem;
  font-weight: 700;
  color: var(--about-accent);
  background: rgba(51, 255, 153, 0.1);
  padding: 0.25rem 0.4rem;
  text-align: center;
}

.tech-points-list h3{
  font-family: var(--about-font-sans);
  font-size: 0.95rem;
  font-weight: 700;
  color: var(--about-text);
  margin: 0 0 0.3rem;
}

.tech-points-list p{
  font-family: var(--about-font-serif);
  font-size: 0.85rem;
  line-height: 1.6;
  color: var(--about-text-muted);
  margin: 0;
}

.tech-visual{
  position: relative;
}

.tech-img{
  display: block;
  width: 100%;
  max-width: 100%;
  height: auto;
  object-fit: cover;
  filter: grayscale(0.15) contrast(1.05);
}

.tech-label{
  font-family: var(--about-font-sans);
  font-size: 0.72rem;
  letter-spacing: 0.14em;
  text-transform: uppercase;
  background: var(--color-bg);
  border: 1px solid rgba(51, 255, 153, 0.5);
  color: var(--about-accent);
  padding: 0.35rem 0.6rem;
  display: inline-flex;
  align-items: center;
  gap: 0.4rem;
}

.tech-label span{
  font-size: 0.62rem;
  color: var(--about-text-muted);
  letter-spacing: 0.12em;
}

.tech-label-1{
  position: absolute;
  top: 0.9rem;
  left: 0.9rem;
}

.tech-label-2{
  position: absolute;
  bottom: 0.9rem;
  right: 0.9rem;
}

/* ===== 资质与认证 ===== */
.about-cert-section{
  padding: 4rem 0;
}

.cert-grid{
  display: grid;
  gap: 1rem;
  margin-top: 1.5rem;
}

.cert-card{
  background: var(--color-bg-card);
  border: 1px solid var(--about-line);
  padding: 1.5rem 1.25rem;
  position: relative;
  clip-path: polygon(0 0, calc(100% - 12px) 0, 100% 12px, 100% 100%, 12px 100%, 0 calc(100% - 12px));
  transition: transform 0.3s cubic-bezier(0.22, 1, 0.36, 1), border-color 0.3s ease;
}

.cert-card:hover{
  transform: translateY(-4px);
  border-color: rgba(51, 255, 153, 0.5);
}

.cert-tag{
  font-family: var(--about-font-sans);
  font-size: 0.65rem;
  letter-spacing: 0.2em;
  color: var(--about-accent);
  text-transform: uppercase;
  display: inline-block;
  margin-bottom: 0.8rem;
  padding: 0.2rem 0.5rem;
  background: rgba(51, 255, 153, 0.08);
  border: 1px solid rgba(51, 255, 153, 0.2);
}

.cert-card h3{
  font-family: var(--about-font-sans);
  font-size: 1.05rem;
  font-weight: 600;
  color: var(--about-text);
  margin: 0 0 0.6rem;
}

.cert-card p{
  font-family: var(--about-font-serif);
  font-size: 0.85rem;
  line-height: 1.75;
  color: var(--about-text-muted);
  margin: 0;
}

/* ===== 合作生态 ===== */
.about-eco-section{
  padding: 4rem 0;
  background: rgba(16, 24, 43, 0.35);
  border-top: 1px solid var(--about-line);
}

.eco-layout{
  display: grid;
  gap: 2rem;
}

.eco-intro .section-label{
  color: var(--about-accent);
  letter-spacing: 0.12em;
  text-transform: uppercase;
  font-family: var(--about-font-sans);
  font-size: 0.875rem;
  font-weight: 700;
  margin-bottom: 1rem;
  display: inline-block;
  border-left: 2px solid var(--about-accent);
  padding-left: 0.6rem;
}

.eco-intro > p:not(.section-label){
  font-family: var(--about-font-serif);
  font-size: 0.925rem;
  line-height: 1.8;
  color: var(--about-text-muted);
  margin: 0;
}

.eco-list{
  display: grid;
  gap: 0.75rem;
}

.eco-item{
  display: grid;
  grid-template-columns: 2.2rem 1fr;
  gap: 0.8rem;
  align-items: flex-start;
  background: rgba(26, 36, 56, 0.5);
  border: 1px solid var(--about-line);
  padding: 1rem;
  transition: border-color 0.3s ease, background 0.3s ease;
}

.eco-item:hover{
  border-color: rgba(51, 255, 153, 0.4);
  background: rgba(26, 36, 56, 0.8);
}

.eco-item-icon{
  font-family: var(--about-font-sans);
  font-size: 0.8rem;
  font-weight: 700;
  color: var(--about-orange);
  background: rgba(255, 140, 66, 0.1);
  padding: 0.25rem 0.4rem;
  text-align: center;
}

.eco-item h3{
  font-family: var(--about-font-sans);
  font-size: 0.95rem;
  font-weight: 700;
  color: var(--about-text);
  margin: 0 0 0.4rem;
}

.eco-item p{
  font-family: var(--about-font-serif);
  font-size: 0.85rem;
  line-height: 1.7;
  color: var(--about-text-muted);
  margin: 0;
}

.eco-footer-note{
  margin-top: 2.5rem;
  padding-top: 1.5rem;
  border-top: 1px dashed var(--about-line);
}

.eco-footer-note p{
  font-family: var(--about-font-serif);
  font-size: 0.85rem;
  line-height: 1.8;
  color: var(--about-text-muted);
  margin: 0;
}

.eco-footer-note a{
  color: var(--about-accent);
  text-decoration: none;
  border-bottom: 1px solid rgba(51, 255, 153, 0.4);
}

.eco-footer-note a:hover{
  border-bottom-color: var(--about-accent);
}

/* ===== data-reveal 初始态与显现态 ===== */
.page-about [data-reveal]{
  opacity: 0;
  transform: translateY(18px);
  transition: opacity 0.6s cubic-bezier(0.22, 1, 0.36, 1), transform 0.6s cubic-bezier(0.22, 1, 0.36, 1);
  transition-delay: var(--reveal-delay, 0s);
}

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

@media (prefers-reduced-motion: reduce){
  .page-about [data-reveal]{
    opacity: 1;
    transform: none;
    transition: none;
  }
  .timeline-card:hover,
  .coverage-stat-card:hover,
  .cert-card:hover{
    transform: none;
  }
}

/* ===== 平板及以上 ===== */
@media (min-width: 640px){
  .about-hero{
    padding: 4.5rem 0 5rem;
  }

  .about-hero-grid{
    grid-template-columns: minmax(0, 1fr) 300px;
    align-items: start;
    gap: 2rem;
  }

  .coverage-stats{
    grid-template-columns: repeat(3, 1fr);
  }

  .cert-grid{
    grid-template-columns: repeat(2, 1fr);
  }

  .eco-layout{
    grid-template-columns: minmax(0, 0.85fr) minmax(0, 1.15fr);
    gap: 3rem;
    align-items: start;
  }

  .story-side-info{
    position: sticky;
    top: 2rem;
  }
}

/* ===== 桌面端 ===== */
@media (min-width: 900px){
  .about-story-wrap{
    grid-template-columns: minmax(0, 1.3fr) minmax(0, 0.7fr);
    gap: 3.5rem;
    align-items: start;
  }

  .about-timeline{
    margin-left: auto;
    margin-right: auto;
    max-width: 760px;
  }

  .about-timeline::before{
    left: 50%;
    transform: translateX(-1px);
  }

  .timeline-item{
    width: 50%;
    padding-left: 2.5rem;
    padding-right: 2rem;
  }

  .timeline-item:nth-child(odd){
    left: 0;
    padding-left: 0;
    padding-right: 3rem;
    text-align: right;
  }

  .timeline-item:nth-child(even){
    left: 50%;
    padding-left: 3rem;
    padding-right: 0;
  }

  .timeline-marker{
    left: auto;
    right: -8px;
    top: 0.15rem;
  }

  .timeline-item:nth-child(odd) .timeline-marker{
    left: auto;
    right: -8px;
  }

  .timeline-item:nth-child(even) .timeline-marker{
    left: -8px;
    right: auto;
  }

  .timeline-card{
    text-align: left;
  }

  .timeline-item:nth-child(odd) .timeline-card{
    text-align: left;
  }

  .coverage-hero{
    grid-template-columns: minmax(0, 0.8fr) minmax(0, 1.2fr);
    align-items: center;
    gap: 2.5rem;
  }

  .coverage-stats{
    grid-template-columns: repeat(2, 1fr);
  }

  .about-tech-grid{
    grid-template-columns: minmax(0, 1fr) minmax(0, 1fr);
    align-items: center;
    gap: 3rem;
  }

  .tech-points-list{
    grid-template-columns: repeat(2, 1fr);
  }
}

/* ===== 大桌面端 ===== */
@media (min-width: 1200px){
  .about-hero-grid{
    grid-template-columns: minmax(0, 1fr) 340px;
    gap: 3rem;
  }

  .cert-grid{
    grid-template-columns: repeat(4, 1fr);
  }

  .eco-layout{
    grid-template-columns: minmax(0, 0.9fr) minmax(0, 1.1fr);
    gap: 4rem;
  }
}

.page-about {
  --reveal-delay: 0.3s;
}