/* ================= 品牌故事页 · page-about ================= */
.page-about{
  --about-rail:220px;
  --about-paper-ink:rgba(36,30,26,.78);
  --about-hair-paper:rgba(36,30,26,.16);
  background:var(--ink-deep);
}

/* ---------- 封面 ---------- */
.page-about .about-cover{
  position:relative;
  overflow:hidden;
  padding:calc(var(--header-h) + clamp(1.75rem,6vh,3.5rem)) 0 clamp(2rem,6vh,3.25rem);
  background:
    radial-gradient(120% 90% at 88% -10%,rgba(0,230,118,.14),transparent 60%),
    radial-gradient(100% 80% at 4% 108%,rgba(208,85,43,.16),transparent 62%),
    var(--ink-deep);
  border-bottom:1px solid var(--line-hair);
}
.page-about .about-cover::before{
  content:"";
  position:absolute;
  left:0;right:0;bottom:0;height:1px;
  background:linear-gradient(90deg,transparent,var(--signal-green) 24%,transparent 62%);
  opacity:.55;
}
.page-about .about-cover-inner{
  display:grid;
  gap:1rem;
}
.page-about .about-kicker{
  color:var(--amber-node);
  letter-spacing:.18em;
  text-transform:uppercase;
}
.page-about .about-title{
  margin:.2rem 0 0;
  font-family:var(--font-display);
  font-weight:800;
  font-size:clamp(2.3rem,7.5vw,4.7rem);
  line-height:.98;
  letter-spacing:-.02em;
  color:var(--paper-cream);
  max-width:15ch;
}
.page-about .about-lede{
  margin:.35rem 0 0;
  max-width:62ch;
  color:var(--mist-gray);
  font-size:1.0625rem;
  line-height:1.75;
}

.page-about .about-index{
  list-style:none;
  margin:1.4rem 0 0;
  padding:1px;
  display:grid;
  grid-template-columns:repeat(2,minmax(0,1fr));
  gap:1px;
  background:var(--line-hair);
  border:1px solid var(--line-hair);
}
.page-about .about-index li{
  background:var(--ink-panel);
  padding:.95rem 1.05rem;
  display:flex;
  flex-direction:column;
  gap:.3rem;
  min-width:0;
}
.page-about .about-index-key{
  font-size:var(--step-index);
  letter-spacing:.12em;
  text-transform:uppercase;
  color:var(--mist-gray);
}
.page-about .about-index-val{
  font-family:var(--font-mono);
  font-variant-numeric:tabular-nums;
  font-size:clamp(1.4rem,3.4vw,1.95rem);
  line-height:1;
  color:var(--paper-cream);
}
.page-about .about-index-val.is-signal{color:var(--signal-green);}
.page-about .about-index-val.is-amber{color:var(--amber-node);}

@media (min-width:720px){
  .page-about .about-index{grid-template-columns:repeat(4,minmax(0,1fr));}
}

/* ---------- 主体骨架：左侧时间线轴 + 右侧章节 ---------- */
.page-about .about-body{
  display:grid;
  gap:clamp(1.75rem,5vw,3rem);
  padding-top:clamp(2.25rem,6vh,4rem);
  padding-bottom:clamp(3rem,9vh,6rem);
}

.page-about .rail-title{
  color:var(--mist-gray);
  margin:0 0 .75rem;
}
.page-about .rail-list{
  list-style:none;
  margin:0;
  padding:0 0 .35rem;
  display:flex;
  gap:.5rem;
  overflow-x:auto;
  -webkit-overflow-scrolling:touch;
  scrollbar-width:thin;
}
.page-about .rail-link{
  display:inline-flex;
  align-items:center;
  gap:.45rem;
  padding:.45rem .8rem;
  border:1px solid var(--line-hair);
  background:var(--ink-panel);
  color:var(--mist-gray);
  text-decoration:none;
  font-size:.8125rem;
  white-space:nowrap;
  transition:color var(--dur) var(--ease),border-color var(--dur) var(--ease);
}
.page-about .rail-link:hover,
.page-about .rail-link:focus-visible{
  color:var(--paper-cream);
  border-color:var(--amber-node);
}
.page-about .rail-num{
  font-family:var(--font-mono);
  font-variant-numeric:tabular-nums;
  font-size:var(--step-index);
  color:var(--rust-orange);
}
.page-about .rail-name{letter-spacing:.06em;}

@media (min-width:1080px){
  .page-about .about-body{
    grid-template-columns:var(--about-rail) minmax(0,1fr);
    gap:clamp(2.5rem,6vw,5rem);
    align-items:start;
  }
  .page-about .story-rail{
    position:sticky;
    top:calc(var(--header-h) + 2.5rem);
  }
  .page-about .rail-list{
    display:block;
    overflow:visible;
    padding:0;
    margin-left:.35rem;
    border-left:1px solid var(--line-hair);
  }
  .page-about .rail-link{
    display:grid;
    grid-template-columns:2.4rem minmax(0,1fr);
    align-items:baseline;
    gap:.4rem;
    padding:.52rem 0 .52rem .9rem;
    border:0;
    background:transparent;
    position:relative;
    font-size:.875rem;
  }
  .page-about .rail-link::before{
    content:"";
    position:absolute;
    left:-1px;
    top:1rem;
    width:8px;
    height:1px;
    background:var(--line-hair);
    transition:width var(--dur) var(--ease),background var(--dur) var(--ease);
  }
  .page-about .rail-link:hover::before,
  .page-about .rail-link:focus-visible::before{
    width:16px;
    background:var(--amber-node);
  }
  .page-about .rail-link:hover,
  .page-about .rail-link:focus-visible{
    border-color:transparent;
  }
}

/* ---------- 章节 ---------- */
.page-about .about-content{
  min-width:0;
  display:grid;
}
.page-about .chapter{
  display:grid;
  gap:clamp(1.25rem,3vw,1.9rem);
  padding-bottom:clamp(2.25rem,6vw,3.5rem);
  margin-bottom:clamp(2.25rem,6vw,3.5rem);
  border-bottom:1px solid var(--line-hair);
  scroll-margin-top:calc(var(--header-h) + 1.5rem);
}
.page-about .chapter:last-child{
  border-bottom:0;
  margin-bottom:0;
  padding-bottom:0;
}

.page-about .chapter-head{
  display:grid;
  grid-template-columns:auto minmax(0,1fr);
  gap:.9rem 1.1rem;
  align-items:start;
}
.page-about .chapter-num{
  font-family:var(--font-mono);
  font-variant-numeric:tabular-nums;
  font-size:clamp(1.9rem,5vw,3.1rem);
  line-height:.85;
  color:var(--rust-orange);
  transition:color var(--dur) var(--ease);
}
.page-about .chapter.is-active .chapter-num{color:var(--signal-green);}
.page-about .chapter-head-text{display:grid;gap:.4rem;}
.page-about .chapter-title{
  margin:0;
  font-family:var(--font-display);
  font-weight:800;
  font-size:clamp(1.5rem,3.6vw,2.2rem);
  line-height:1.1;
  letter-spacing:-.01em;
  color:var(--paper-cream);
}
.page-about .chapter-lede{
  margin:0;
  max-width:58ch;
  color:var(--mist-gray);
  font-size:1.0625rem;
  line-height:1.75;
}

/* 奶油阅读层 */
.page-about .chapter-prose{
  background-color:var(--paper-cream);
  background-image:repeating-linear-gradient(180deg,transparent 0 27px,rgba(36,30,26,.05) 27px 28px);
  color:var(--black-brown);
  padding:clamp(1.35rem,3.6vw,2.5rem);
  border-radius:var(--radius);
}
.page-about .chapter-prose p{
  margin:0 0 1.05rem;
  max-width:64ch;
  line-height:1.75;
}
.page-about .chapter-prose p:last-child{margin-bottom:0;}
.page-about .chapter-prose strong{
  color:var(--green-deep);
  font-weight:700;
}

/* 深色数据层 */
.page-about .chapter-data{
  background:var(--ink-panel);
  border:1px solid var(--line-hair);
  border-radius:var(--radius);
  padding:clamp(1.35rem,3.6vw,2.25rem);
  display:grid;
  gap:1rem;
}
.page-about .chapter-data p{
  margin:0;
  max-width:62ch;
  color:var(--mist-gray);
  line-height:1.75;
}
.page-about .scope-lede{
  color:var(--paper-cream) !important;
  font-family:var(--font-display);
  font-size:clamp(1.15rem,2.4vw,1.45rem);
  line-height:1.4 !important;
  letter-spacing:-.005em;
}
.page-about .scope-actions{
  display:flex;
  flex-wrap:wrap;
  gap:.75rem;
  margin-top:.35rem;
}

/* ---------- 图片框 ---------- */
.page-about .media-frame{
  margin:0;
  border:1px solid var(--line-hair);
  background:var(--ink-deep);
  border-radius:var(--radius);
  overflow:hidden;
}
.page-about .media-frame.on-paper{
  border-color:var(--about-hair-paper);
  background:var(--paper-dim);
}
.page-about .media-frame img{
  display:block;
  width:100%;
  height:auto;
  object-fit:cover;
}
.page-about .media-caption{
  padding:.7rem .9rem;
  font-size:var(--step-note);
  color:var(--mist-gray);
  border-top:1px solid var(--line-hair);
}
.page-about .media-frame.on-paper .media-caption{
  color:var(--about-paper-ink);
  border-top-color:var(--about-hair-paper);
}

/* ---------- 分级结构 ---------- */
.page-about .tier-stack{
  display:grid;
  gap:.65rem;
}
.page-about .tier{
  background:var(--ink-panel);
  border:1px solid var(--line-hair);
  border-left:3px solid var(--rust-orange);
  border-radius:var(--radius);
}
.page-about .tier:nth-child(2){border-left-color:var(--amber-node);}
.page-about .tier:nth-child(3){border-left-color:var(--mist-gray);}
.page-about .tier-summary{
  display:grid;
  grid-template-columns:auto minmax(0,1fr) auto;
  gap:.9rem;
  align-items:center;
  padding:1rem 1.1rem;
  cursor:pointer;
  list-style:none;
}
.page-about .tier-summary::-webkit-details-marker{display:none;}
.page-about .tier-summary:focus-visible{outline:2px solid var(--signal-green);outline-offset:-2px;}
.page-about .tier-level{
  font-family:var(--font-mono);
  font-size:var(--step-index);
  letter-spacing:.1em;
  color:var(--mist-gray);
}
.page-about .tier-name{
  font-family:var(--font-display);
  font-weight:700;
  font-size:1.0625rem;
  letter-spacing:.01em;
  color:var(--paper-cream);
  min-width:0;
}
.page-about .tier-count{
  font-family:var(--font-mono);
  font-variant-numeric:tabular-nums;
  font-size:1.45rem;
  line-height:1;
  color:var(--signal-green);
}
.page-about .tier-body{
  padding:0 1.1rem 1.15rem;
  border-top:1px solid var(--line-hair);
  padding-top:1rem;
}
.page-about .tier-body p{
  margin:0;
  color:var(--mist-gray);
  font-size:.9375rem;
  line-height:1.72;
  max-width:64ch;
}

/* ---------- 赛季阶段 ---------- */
.page-about .phase-list{
  list-style:none;
  margin:0;
  padding:0;
  display:grid;
  gap:.75rem;
}
.page-about .phase{
  background:var(--paper-dim);
  border:1px solid var(--about-hair-paper);
  border-top:3px solid var(--rust-orange);
  padding:1rem 1.1rem 1.15rem;
}
.page-about .phase:nth-child(2){border-top-color:var(--amber-node);}
.page-about .phase:nth-child(3){border-top-color:var(--green-deep);}
.page-about .phase:nth-child(4){border-top-color:var(--mist-gray);}
.page-about .phase-key{
  font-family:var(--font-mono);
  font-size:var(--step-index);
  letter-spacing:.14em;
  color:var(--rust-orange);
}
.page-about .phase-name{
  margin:.3rem 0 .5rem;
  font-family:var(--font-display);
  font-weight:700;
  font-size:1.15rem;
  color:var(--black-brown);
}
.page-about .phase p{
  margin:0;
  font-size:.9375rem;
  line-height:1.72;
  color:var(--about-paper-ink);
}
@media (min-width:760px){
  .page-about .phase-list{grid-template-columns:repeat(2,minmax(0,1fr));}
}

/* ---------- 三级校验流程 ---------- */
.page-about .flow{
  list-style:none;
  margin:0;
  padding:0;
  display:grid;
  gap:1rem;
}
.page-about .flow-node{
  background:var(--ink-deep);
  border:1px solid var(--line-hair);
  border-top:2px solid var(--mist-gray);
  border-radius:var(--radius);
  padding:1.05rem 1.15rem 1.2rem;
  display:grid;
  gap:.5rem;
  align-content:start;
  transition:transform var(--dur) var(--ease),border-color var(--dur) var(--ease);
}
.page-about .flow-node:nth-child(2){border-top-color:var(--amber-node);}
.page-about .flow-node:nth-child(3){border-top-color:var(--signal-green);}
.page-about .flow-node:hover{transform:translateY(-2px);}
.page-about .flow-step{
  font-family:var(--font-mono);
  font-size:var(--step-index);
  letter-spacing:.14em;
  color:var(--mist-gray);
}
.page-about .flow-name{
  margin:0;
  font-family:var(--font-display);
  font-weight:800;
  font-size:1.25rem;
  letter-spacing:-.01em;
  color:var(--paper-cream);
}
.page-about .flow-node p{
  margin:0;
  font-size:.9375rem;
  line-height:1.7;
  color:var(--mist-gray);
}
.page-about .flow-hint{
  justify-self:start;
  margin-top:.35rem;
  padding:.3rem .55rem;
  border:1px solid rgba(255,193,7,.42);
  font-family:var(--font-mono);
  font-size:var(--step-index);
  letter-spacing:.08em;
  color:var(--amber-node);
  transition:box-shadow var(--dur) var(--ease),border-color var(--dur) var(--ease);
}
.page-about .flow-node:hover .flow-hint{
  border-color:var(--amber-node);
  box-shadow:0 0 0 3px rgba(255,193,7,.12);
}
@media (min-width:900px){
  .page-about .flow{grid-template-columns:repeat(3,minmax(0,1fr));gap:1.1rem;}
}

/* ---------- 团队 ---------- */
.page-about .team-grid{
  list-style:none;
  margin:0;
  padding:1px;
  display:grid;
  gap:1px;
  background:var(--line-hair);
  border:1px solid var(--line-hair);
}
.page-about .team-cell{
  background:var(--ink-panel);
  padding:1.15rem 1.15rem 1.25rem;
  display:grid;
  gap:.4rem;
  align-content:start;
}
.page-about .team-num{
  font-family:var(--font-mono);
  font-variant-numeric:tabular-nums;
  font-size:clamp(2rem,5vw,2.7rem);
  line-height:1;
  color:var(--signal-green);
}
.page-about .team-num.is-amber{color:var(--amber-node);}
.page-about .team-num.is-mist{color:var(--mist-gray);}
.page-about .team-label{
  font-family:var(--font-display);
  font-weight:700;
  font-size:1rem;
  color:var(--paper-cream);
}
.page-about .team-note{
  font-size:var(--step-note);
  line-height:1.65;
  color:var(--mist-gray);
}
@media (min-width:760px){
  .page-about .team-grid{grid-template-columns:repeat(3,minmax(0,1fr));}
}

.page-about .about-signal{margin-top:.25rem;}

/* ---------- 迭代时间线 ---------- */
.page-about .about-timeline{
  margin:0;
}
.page-about .about-timeline .timeline-time{
  font-size:var(--step-note);
  letter-spacing:.1em;
}
.page-about .about-timeline .timeline-body p{
  margin:0;
  font-size:.9375rem;
  line-height:1.72;
  color:var(--mist-gray);
  max-width:62ch;
}

/* ---------- 审计 ---------- */
.page-about .audit-list{
  list-style:none;
  margin:0;
  padding:0;
  display:grid;
  gap:.75rem;
}
.page-about .audit-item{
  display:grid;
  grid-template-columns:auto minmax(0,1fr);
  gap:1rem;
  align-items:start;
  background:var(--paper-dim);
  border-left:3px solid var(--rust-orange);
  padding:.95rem 1.05rem 1.05rem;
}
.page-about .audit-key{
  font-family:var(--font-mono);
  font-variant-numeric:tabular-nums;
  font-size:var(--step-index);
  letter-spacing:.1em;
  color:var(--rust-orange);
  padding-top:.2rem;
}
.page-about .audit-name{
  margin:0 0 .35rem;
  font-family:var(--font-display);
  font-weight:700;
  font-size:1.0625rem;
  color:var(--black-brown);
}
.page-about .audit-item p{
  margin:0;
  font-size:.9375rem;
  line-height:1.7;
  color:var(--about-paper-ink);
}

/* ---------- 延伸阅读 ---------- */
.page-about .related-list{
  list-style:none;
  margin:0;
  padding:0;
  display:grid;
  gap:1px;
  background:var(--line-hair);
  border:1px solid var(--line-hair);
}
.page-about .related-link{
  display:grid;
  gap:.35rem;
  padding:1rem 1.1rem;
  background:var(--ink-panel);
  text-decoration:none;
  transition:background var(--dur) var(--ease),padding-left var(--dur) var(--ease);
}
.page-about .related-link:hover,
.page-about .related-link:focus-visible{
  background:var(--ink-deep);
  padding-left:1.35rem;
}
.page-about .related-title{
  font-family:var(--font-display);
  font-weight:700;
  font-size:1.0625rem;
  color:var(--paper-cream);
  letter-spacing:.01em;
}
.page-about .related-desc{
  font-size:var(--step-note);
  line-height:1.65;
  color:var(--mist-gray);
}
@media (min-width:760px){
  .page-about .related-list{grid-template-columns:repeat(2,minmax(0,1fr));}
  .page-about .related-list > li:last-child{grid-column:span 2;}
}

/* ---------- 动效收敛 ---------- */
@media (prefers-reduced-motion:reduce){
  .page-about .flow-node:hover{transform:none;}
  .page-about .related-link:hover,
  .page-about .related-link:focus-visible{padding-left:1.1rem;}
}
</main>