.page-about{
  --about-rail-w: 300px;
  background: var(--ink);
  color: var(--mist);
  font-family: var(--font-sans);
}

.page-about .about-shell{
  max-width: var(--shell);
  margin: 0 auto;
  padding: 26px var(--gutter) 72px;
}

/* ---------- 左侧导览 ---------- */
.page-about .about-rail{
  border-bottom: var(--line);
  padding-bottom: 20px;
  margin-bottom: 8px;
}
.page-about .about-rail-label{
  margin: 0 0 12px;
  color: var(--lime);
}
.page-about .about-title{
  margin: 0;
  font-size: clamp(28px, 7.6vw, 40px);
  font-weight: 900;
  line-height: 1.03;
  letter-spacing: -.02em;
  color: var(--mist);
}
.page-about .about-rail-note{
  margin: 12px 0 0;
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: .16em;
  color: var(--mute);
}
.page-about .about-years{
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
  margin-top: 16px;
}
.page-about .about-year{
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: .1em;
  color: var(--mute);
  text-decoration: none;
  border: 1px solid var(--grid);
  border-radius: 2px;
  padding: 4px 8px;
  transition: color .18s var(--ease), background-color .18s var(--ease), border-color .18s var(--ease);
}
.page-about .about-year:hover,
.page-about .about-year:focus-visible{
  color: var(--ink-on-lime);
  background: var(--lime);
  border-color: var(--lime);
}

/* ---------- 右栏通用 ---------- */
.page-about .about-flow{ min-width: 0; }

.page-about .breadcrumb{
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
  margin: 18px 0 24px;
  font-size: 12px;
  color: var(--mute);
}
.page-about .breadcrumb a{
  color: var(--mute);
  text-decoration: none;
}
.page-about .breadcrumb a:hover,
.page-about .breadcrumb a:focus-visible{ color: var(--lime); }

.page-about .about-sec{
  padding: 38px 0 42px;
  border-top: var(--line);
}
.page-about .about-sec-title{
  margin: 10px 0 16px;
  font-size: clamp(23px, 5.2vw, 32px);
  font-weight: 900;
  line-height: 1.08;
  letter-spacing: -.02em;
  color: var(--mist);
}
.page-about .about-sec p{
  margin: 0 0 14px;
  max-width: 64ch;
  font-size: 15px;
  line-height: 1.7;
  color: var(--mute);
}
.page-about .about-lead{
  font-size: 16.5px;
  line-height: 1.65;
  color: var(--mist) !important;
}
.page-about .about-sub{
  margin: 26px 0 10px;
  font-family: var(--font-mono);
  font-size: 12px;
  font-weight: 700;
  letter-spacing: .18em;
  color: var(--orange);
}

/* ---------- 数字条 ---------- */
.page-about .about-figures{
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: 1px;
  margin: 26px 0 0;
  background: var(--grid);
  border: var(--line);
}
.page-about .about-fig{
  background: var(--ink);
  padding: 16px 12px;
}
.page-about .about-fig-num{
  display: block;
  font-family: var(--font-mono);
  font-size: clamp(22px, 6.4vw, 32px);
  font-weight: 700;
  line-height: 1;
  letter-spacing: -.02em;
  color: var(--lime);
}
.page-about .about-fig-label{
  display: block;
  margin-top: 8px;
  font-size: 11px;
  letter-spacing: .12em;
  line-height: 1.4;
  color: var(--mute);
}

/* ---------- 字段标签 ---------- */
.page-about .about-fields{
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
  margin: 16px 0 0;
  padding: 0;
  list-style: none;
}
.page-about .about-fields li{
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: .12em;
  color: var(--lime);
  border: 1px solid rgba(184, 255, 46, .35);
  border-radius: 2px;
  padding: 5px 9px;
}

/* ---------- 图片 ---------- */
.page-about .about-media{
  margin: 24px 0 0;
  border: var(--line);
  overflow: hidden;
  background: var(--layer);
}
.page-about .about-media img{
  display: block;
  width: 100%;
  height: auto;
  max-width: 100%;
  object-fit: cover;
  filter: contrast(1.08) saturate(.72);
}

/* ---------- 时间线 ---------- */
.page-about .about-timeline-wrap{
  position: relative;
  margin-top: 22px;
}
.page-about .about-timeline-bg{
  position: absolute;
  inset: 0;
  width: 100%;
  height: 100%;
  object-fit: cover;
  opacity: .16;
  filter: grayscale(.5) contrast(1.25);
  pointer-events: none;
}
.page-about .about-timeline{
  position: relative;
  z-index: 1;
  list-style: none;
  margin: 0;
  padding: 6px 0 0 26px;
  border-left: 1px solid var(--grid);
}
.page-about .tl-item{
  position: relative;
  padding: 0 0 28px;
  scroll-margin-top: calc(var(--rail-h) + var(--index-h) + 20px);
}
.page-about .tl-item::before{
  content: "";
  position: absolute;
  left: -31px;
  top: 5px;
  width: 9px;
  height: 9px;
  background: var(--lime);
  transition: background-color .18s var(--ease), box-shadow .18s var(--ease);
}
.page-about .tl-item:hover::before,
.page-about .tl-item:target::before{
  background: var(--white);
  box-shadow: 0 0 0 4px rgba(184, 255, 46, .2);
}
.page-about .tl-year{
  display: block;
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: .16em;
  color: var(--lime);
}
.page-about .tl-name{
  margin: 6px 0 8px;
  font-size: 18px;
  font-weight: 800;
  letter-spacing: -.01em;
  color: var(--mist);
}
.page-about .tl-text{
  margin: 0;
  font-size: 14.5px;
  line-height: 1.65;
  color: var(--mute);
  max-width: 56ch;
}

/* ---------- 珠宝色章节 ---------- */
.page-about .about-band{
  border-top: 0;
  margin-left: calc(-1 * var(--gutter));
  margin-right: calc(-1 * var(--gutter));
  padding-left: var(--gutter);
  padding-right: var(--gutter);
}
.page-about .about-band--teal{ background: var(--teal); }
.page-about .about-band--wine{ background: var(--wine); }
.page-about .about-band--indigo{ background: var(--indigo); }

/* ---------- 分段切换 ---------- */
.page-about .about-tabs{ margin-top: 22px; }
.page-about .about-tab-list{
  display: flex;
  flex-wrap: wrap;
  gap: 0;
  border-bottom: var(--line);
}
.page-about .about-tab{
  appearance: none;
  background: transparent;
  border: 1px solid var(--grid);
  border-bottom: 0;
  border-radius: 0;
  margin: 0 6px -1px 0;
  padding: 10px 13px;
  font-family: var(--font-sans);
  font-size: 13px;
  font-weight: 700;
  letter-spacing: .04em;
  color: var(--mute);
  cursor: pointer;
  display: flex;
  align-items: baseline;
  gap: 6px;
  transition: color .18s var(--ease), background-color .18s var(--ease), border-color .18s var(--ease);
}
.page-about .about-tab span{
  font-family: var(--font-mono);
  font-size: 11px;
  font-weight: 400;
  letter-spacing: .06em;
  color: var(--lime);
}
.page-about .about-tab:hover{ color: var(--mist); }
.page-about .about-tab[aria-selected="true"]{
  background: var(--lime);
  border-color: var(--lime);
  color: var(--ink-on-lime);
}
.page-about .about-tab[aria-selected="true"] span{ color: var(--ink-on-lime); }
.page-about .about-panel{ padding: 18px 0 0; }
.page-about .about-panel ul{
  margin: 0;
  padding: 0;
  list-style: none;
  display: grid;
  gap: 10px;
}
.page-about .about-panel li{
  position: relative;
  padding-left: 16px;
  font-size: 14.5px;
  line-height: 1.62;
  color: var(--mute);
  max-width: 62ch;
}
.page-about .about-panel li::before{
  content: "";
  position: absolute;
  left: 0;
  top: .62em;
  width: 6px;
  height: 1px;
  background: var(--lime);
}

/* ---------- 流程图 ---------- */
.page-about .about-flowchart{
  display: grid;
  gap: 10px;
  margin: 22px 0 0;
  padding: 0;
  list-style: none;
}
.page-about .flow-seg{
  background: rgba(232, 240, 238, .05);
  border: 1px solid var(--grid);
  padding: 16px 14px;
  transition: background-color .2s var(--ease);
}
.page-about .flow-seg:hover{ background: rgba(184, 255, 46, .1); }
.page-about .flow-num{
  display: block;
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: .18em;
  color: var(--lime);
}
.page-about .flow-name{
  margin: 6px 0 10px;
  font-size: 17px;
  font-weight: 800;
  letter-spacing: -.01em;
  color: var(--mist);
}
.page-about .flow-io{
  margin: 0 0 6px;
  font-size: 12.5px;
  line-height: 1.55;
  color: var(--mute);
}
.page-about .flow-key{
  display: inline-block;
  margin-right: 6px;
  padding: 1px 5px;
  border: 1px solid rgba(255, 106, 43, .45);
  border-radius: 2px;
  font-family: var(--font-mono);
  font-size: 10px;
  letter-spacing: .12em;
  color: var(--orange);
}

/* ---------- 共建 ---------- */
.page-about .about-eco-grid{
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 1px;
  margin: 22px 0 20px;
  background: rgba(232, 240, 238, .16);
  border: 1px solid rgba(232, 240, 238, .16);
}
.page-about .about-eco-cell{
  background: var(--indigo);
  padding: 16px 14px;
}
.page-about .about-eco-cell:last-child{ grid-column: 1 / -1; }
.page-about .about-eco-num{
  display: block;
  font-family: var(--font-mono);
  font-size: clamp(26px, 7vw, 38px);
  font-weight: 700;
  line-height: 1;
  color: var(--lime);
}
.page-about .about-eco-label{
  display: block;
  margin-top: 8px;
  font-size: 11px;
  letter-spacing: .12em;
  line-height: 1.45;
  color: var(--mist);
}
.page-about .about-eco-link{
  display: inline-block;
  margin-top: 4px;
  text-decoration: none;
}

/* ---------- 下一步 ---------- */
.page-about .about-next{
  display: grid;
  gap: 1px;
  margin: 22px 0 0;
  padding: 0;
  list-style: none;
  background: var(--grid);
  border: 1px solid var(--grid);
}
.page-about .about-next a{
  display: block;
  background: var(--ink);
  padding: 16px;
  text-decoration: none;
  transition: background-color .18s var(--ease);
}
.page-about .about-next a:hover,
.page-about .about-next a:focus-visible{ background: var(--layer); }
.page-about .nx-label{
  display: block;
  font-family: var(--font-mono);
  font-size: 10px;
  letter-spacing: .18em;
  color: var(--lime);
}
.page-about .nx-title{
  display: block;
  margin-top: 6px;
  font-size: 15px;
  font-weight: 700;
  line-height: 1.5;
  color: var(--mist);
}

/* ---------- 中屏 ---------- */
@media (min-width: 620px){
  .page-about .about-next{ grid-template-columns: repeat(2, minmax(0, 1fr)); }
  .page-about .about-eco-grid{ grid-template-columns: repeat(3, minmax(0, 1fr)); }
  .page-about .about-eco-cell:last-child{ grid-column: auto; }
}

@media (min-width: 860px){
  .page-about .about-flowchart{
    grid-template-columns: repeat(5, minmax(0, 1fr));
    gap: 0;
    border: 1px solid var(--grid);
  }
  .page-about .flow-seg{
    border: 0;
    border-left: var(--line);
    padding: 20px 30px 22px 16px;
    clip-path: polygon(0 0, 100% 0, calc(100% - 16px) 100%, 0 100%);
  }
  .page-about .flow-seg:first-child{
    border-left: 0;
  }
  .page-about .flow-seg:last-child{
    clip-path: polygon(0 0, 100% 0, 100% 100%, 0 100%);
  }
}

/* ---------- 桌面分屏 ---------- */
@media (min-width: 900px){
  .page-about .about-shell{
    display: grid;
    grid-template-columns: var(--about-rail-w) minmax(0, 1fr);
    column-gap: 56px;
    padding-top: 44px;
  }
  .page-about .about-rail{
    position: sticky;
    top: calc(var(--rail-h) + var(--index-h) + 28px);
    align-self: start;
    margin: 0;
    padding: 0 26px 0 0;
    border-bottom: 0;
    border-right: var(--line);
  }
  .page-about .about-rail-main{
    display: flex;
    align-items: flex-start;
    gap: 18px;
  }
  .page-about .about-title{
    writing-mode: vertical-rl;
    font-size: clamp(28px, 2.9vw, 36px);
    letter-spacing: .06em;
    line-height: 1.1;
  }
  .page-about .about-rail-note{
    writing-mode: vertical-rl;
    margin: 0;
    font-size: 10px;
    letter-spacing: .3em;
  }
  .page-about .about-years{
    flex-direction: column;
    align-items: flex-start;
    gap: 7px;
    margin-top: 26px;
    padding-top: 18px;
    border-top: var(--line);
  }
  .page-about .about-year{
    position: relative;
    border: 0;
    padding: 0 0 0 12px;
    font-size: 12px;
  }
  .page-about .about-year::before{
    content: "";
    position: absolute;
    left: 0;
    top: .58em;
    width: 6px;
    height: 1px;
    background: var(--grid);
    transition: background-color .18s var(--ease);
  }
  .page-about .about-year:hover,
  .page-about .about-year:focus-visible{
    background: transparent;
    color: var(--lime);
  }
  .page-about .about-year:hover::before,
  .page-about .about-year:focus-visible::before{ background: var(--lime); }

  .page-about .about-sec{ padding: 46px 0 50px; }
  .page-about .about-band{
    margin-left: -32px;
    padding-left: 32px;
  }
  .page-about .about-timeline{ padding-left: 30px; }
  .page-about .tl-item::before{ left: -35px; }
}
<<<END>>>