.page-about{
  background: var(--ink-900);
  color: var(--paper);
  padding-bottom: clamp(40px, 8vw, 96px);
}

.page-about .about-shell{
  padding-top: clamp(20px, 3.5vw, 40px);
}

.page-about .about-crumb{
  margin-bottom: clamp(20px, 4vw, 44px);
  color: var(--slate-300);
  font-size: 13px;
}
.page-about .about-crumb a{
  color: var(--slate-300);
  text-decoration: none;
  border-bottom: 1px solid transparent;
  transition: border-color var(--dur) var(--ease), color var(--dur) var(--ease);
}
.page-about .about-crumb a:hover,
.page-about .about-crumb a:focus-visible{
  color: var(--paper);
  border-bottom-color: var(--signal);
}

.page-about .about-split{
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: clamp(28px, 5vw, 56px);
}

/* ---------- left rail ---------- */
.page-about .about-rail{
  position: relative;
  padding-bottom: clamp(20px, 3vw, 28px);
  border-bottom: var(--hair);
}

.page-about .about-title{
  margin: 12px 0 18px;
  font-family: var(--font-display);
  font-size: clamp(2rem, 6.4vw, 3rem);
  font-weight: 900;
  letter-spacing: -0.04em;
  line-height: 1.12;
  color: var(--paper);
}

.page-about .about-lede{
  margin: 0 0 24px;
  max-width: 34em;
  font-size: 15px;
  line-height: 1.8;
  color: var(--slate-300);
}

.page-about .about-fig{
  margin: 0 0 10px;
  border: var(--hair);
  background: var(--ink-800);
  overflow: hidden;
}
.page-about .about-fig img{
  display: block;
  width: 100%;
  max-width: 100%;
  height: auto;
  object-fit: cover;
  filter: saturate(0.9);
}
.page-about .about-fig--start img{
  aspect-ratio: 4 / 3;
}
.page-about .about-fig__cap{
  display: block;
  margin: 0 0 22px;
  padding-top: 8px;
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.02em;
  color: var(--slate-500);
}

.page-about .about-jump{
  margin-top: 4px;
  padding-top: 16px;
  border-top: var(--hair);
}
.page-about .about-jump__label{
  margin: 0 0 10px;
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: 0.18em;
  text-transform: uppercase;
  color: var(--slate-500);
}
.page-about .about-jump__list{
  list-style: none;
  margin: 0;
  padding: 0;
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
}
.page-about .about-jump__list a{
  display: inline-block;
  padding: 6px 11px;
  border: var(--hair);
  color: var(--slate-300);
  font-size: 13px;
  text-decoration: none;
  transition: color var(--dur) var(--ease), border-color var(--dur) var(--ease), background var(--dur) var(--ease);
}
.page-about .about-jump__list a:hover,
.page-about .about-jump__list a:focus-visible{
  color: var(--paper);
  border-color: var(--signal);
  background: var(--ink-700);
}

.page-about .about-rail__note{
  margin: 18px 0 0;
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: 0.14em;
  color: var(--slate-500);
}

/* ---------- right flow ---------- */
.page-about .about-sec{
  scroll-margin-top: 96px;
  padding: 0 0 clamp(30px, 5vw, 52px);
  border-bottom: var(--hair);
  margin-bottom: clamp(30px, 5vw, 52px);
}
.page-about .about-sec:last-child{
  border-bottom: 0;
  margin-bottom: 0;
  padding-bottom: 0;
}

.page-about .about-h2{
  margin: 10px 0 18px;
  font-family: var(--font-display);
  font-size: clamp(1.35rem, 3.4vw, 2rem);
  font-weight: 900;
  letter-spacing: -0.02em;
  line-height: 1.28;
  color: var(--paper);
}

.page-about .about-p{
  margin: 0 0 16px;
  font-size: 15px;
  line-height: 1.85;
  color: var(--slate-300);
}
.page-about .about-p--narrow{
  max-width: 46em;
}
.page-about .about-p .num{
  font-size: 1.06em;
}

.page-about .about-quote{
  margin: 24px 0 0;
  padding: 18px 20px;
  border-left: 3px solid var(--signal);
  background: var(--ink-800);
}
.page-about .about-quote__txt{
  margin: 0 0 8px;
  font-family: var(--font-display);
  font-size: 17px;
  font-weight: 700;
  line-height: 1.6;
  color: var(--paper);
}
.page-about .about-quote__by{
  margin: 0;
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: 0.12em;
  color: var(--slate-500);
}

/* team cards */
.page-about .about-fig--team{
  margin-top: 22px;
}
.page-about .about-fig--team img{
  aspect-ratio: 10 / 7;
}

.page-about .about-cards{
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 12px;
  margin-top: 22px;
}
.page-about .about-card{
  padding: 16px 18px;
  border: var(--hair);
  background: var(--ink-800);
  box-shadow: 0 1px 0 rgba(0, 0, 0, 0.25);
}
.page-about .about-card__k{
  margin: 0 0 6px;
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: 0.16em;
  color: var(--slate-500);
}
.page-about .about-card__n{
  margin: 0 0 8px;
  font-family: var(--font-mono);
  font-size: 26px;
  font-weight: 700;
  line-height: 1.1;
  color: var(--signal);
}
.page-about .about-card__d{
  margin: 0;
  font-size: 14px;
  line-height: 1.75;
  color: var(--slate-300);
}

/* version ruler */
.page-about .about-ruler{
  display: flex;
  align-items: flex-end;
  justify-content: space-between;
  height: 72px;
  margin: 26px 0 0;
  padding: 0 2px;
  border-bottom: 1px solid var(--line);
  background-image: repeating-linear-gradient(to right, var(--line) 0, var(--line) 1px, transparent 1px, transparent 14px);
  background-repeat: repeat-x;
  background-position: bottom left;
  background-size: auto 10px;
}
.page-about .about-ruler__tick{
  width: 1px;
  height: 18px;
  background: var(--line);
}
.page-about .about-ruler__tick:nth-child(2){ height: 26px; }
.page-about .about-ruler__tick:nth-child(3){ height: 34px; }
.page-about .about-ruler__tick:nth-child(4){ height: 44px; }
.page-about .about-ruler__tick:nth-child(5){ height: 52px; }
.page-about .about-ruler__tick:nth-child(6){ height: 60px; }
.page-about .about-ruler__tick--now{
  width: 3px;
  height: 72px;
  background: var(--signal);
}
.page-about .about-ruler__cap{
  margin: 10px 0 26px;
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.04em;
  color: var(--slate-500);
}

/* version stages */
.page-about .about-stage{
  border-top: var(--hair);
}
.page-about .about-stage:last-of-type{
  border-bottom: var(--hair);
}
.page-about .about-stage__sum{
  display: flex;
  align-items: baseline;
  gap: 14px;
  padding: 14px 26px 14px 0;
  position: relative;
  cursor: pointer;
  list-style: none;
}
.page-about .about-stage__sum::-webkit-details-marker{
  display: none;
}
.page-about .about-stage__sum::after{
  content: "+";
  position: absolute;
  right: 4px;
  top: 50%;
  transform: translateY(-50%);
  font-family: var(--font-mono);
  font-size: 16px;
  color: var(--slate-500);
  transition: color var(--dur) var(--ease);
}
.page-about .about-stage[open] > .about-stage__sum::after{
  content: "−";
  color: var(--signal);
}
.page-about .about-stage__sum:hover::after,
.page-about .about-stage__sum:focus-visible::after{
  color: var(--signal);
}
.page-about .about-stage__ver{
  flex: 0 0 auto;
  min-width: 74px;
  font-size: 14px;
  letter-spacing: 0.02em;
  color: var(--signal);
}
.page-about .about-stage__ttl{
  font-family: var(--font-display);
  font-size: 15px;
  font-weight: 700;
  color: var(--paper);
}
.page-about .about-stage__body{
  padding: 0 26px 18px 88px;
}
.page-about .about-stage__body p{
  margin: 0;
  font-size: 14px;
  line-height: 1.8;
  color: var(--slate-300);
}

/* paper block */
.page-about .about-sec--paper{
  border-bottom: 0;
  padding-bottom: 0;
}
.page-about .about-paper{
  padding: clamp(22px, 4vw, 38px);
  border: var(--hair);
  box-shadow: 0 2px 18px rgba(0, 0, 0, 0.22);
}
.page-about .about-paper .about-h2{
  color: var(--ink-900);
}
.page-about .about-paper .about-p{
  color: #3A4A44;
}
.page-about .about-paper .eyebrow{
  color: var(--signal-deep);
}

.page-about .about-stats{
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 1px;
  margin: 24px 0;
  background: #D8D4C8;
  border: 1px solid #D8D4C8;
}
.page-about .about-stat{
  padding: 16px 18px;
  background: var(--paper);
}
.page-about .about-stat__n{
  margin: 0 0 6px;
  font-family: var(--font-mono);
  font-size: 24px;
  font-weight: 700;
  line-height: 1.1;
  color: var(--signal-deep);
  letter-spacing: -0.01em;
  word-break: break-word;
}
.page-about .about-stat__d{
  margin: 0;
  font-size: 13px;
  line-height: 1.65;
  color: #55635D;
}

/* partner folds */
.page-about .about-fold{
  margin-top: 12px;
  border: var(--hair);
  background: var(--ink-800);
}
.page-about .about-fold__sum{
  position: relative;
  padding: 14px 40px 14px 18px;
  font-family: var(--font-display);
  font-size: 14px;
  font-weight: 700;
  color: var(--paper);
  cursor: pointer;
  list-style: none;
}
.page-about .about-fold__sum::-webkit-details-marker{
  display: none;
}
.page-about .about-fold__sum::after{
  content: "展开";
  position: absolute;
  right: 16px;
  top: 50%;
  transform: translateY(-50%);
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: 0.1em;
  color: var(--slate-500);
}
.page-about .about-fold[open] > .about-fold__sum::after{
  content: "收起";
  color: var(--signal);
}
.page-about .about-fold__body{
  padding: 0 18px 16px;
  border-top: var(--hair);
  margin-top: 0;
}
.page-about .about-fold__body p{
  margin: 14px 0 0;
  font-size: 14px;
  line-height: 1.8;
  color: var(--slate-300);
}

/* wide figure */
.page-about .about-fig--wide{
  margin: 24px 0 20px;
}
.page-about .about-fig--wide img{
  aspect-ratio: 7 / 3;
}

/* cta */
.page-about .about-cta{
  margin-top: 30px;
  padding: 22px 20px;
  border: var(--hair);
  border-left: 3px solid var(--signal);
  background: var(--ink-800);
}
.page-about .about-cta__txt{
  margin: 0 0 14px;
  font-family: var(--font-display);
  font-size: 16px;
  font-weight: 700;
  color: var(--paper);
}
.page-about .about-cta__row{
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
}

/* ---------- tablet ---------- */
@media (min-width: 620px){
  .page-about .about-cards{
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }
  .page-about .about-stats{
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }
  .page-about .about-stage__body{
    padding-left: 88px;
  }
}

@media (min-width: 820px){
  .page-about .about-stats{
    grid-template-columns: repeat(4, minmax(0, 1fr));
  }
}

/* ---------- desktop split ---------- */
@media (min-width: 980px){
  .page-about .about-split{
    grid-template-columns: minmax(0, 33%) minmax(0, 1fr);
    gap: clamp(36px, 4.5vw, 72px);
    align-items: start;
  }
  .page-about .about-rail{
    position: sticky;
    top: 92px;
    align-self: start;
    padding-right: clamp(20px, 2.5vw, 36px);
    border-bottom: 0;
    border-right: var(--hair);
    max-height: calc(100vh - 112px);
    overflow-y: auto;
  }
  .page-about .about-rail::before{
    content: "品牌文化 · STAKE站";
    position: absolute;
    right: -9px;
    top: 4px;
    writing-mode: vertical-rl;
    font-family: var(--font-mono);
    font-size: 11px;
    letter-spacing: 0.3em;
    color: var(--slate-500);
    background: var(--ink-900);
    padding: 6px 0;
  }
  .page-about .about-title{
    font-size: clamp(2.2rem, 2.9vw, 3.1rem);
  }
  .page-about .about-cards{
    grid-template-columns: repeat(3, minmax(0, 1fr));
  }
  .page-about .about-p{
    font-size: 16px;
  }
  .page-about .about-stage__body{
    padding-left: 88px;
  }
}

@media (prefers-reduced-motion: reduce){
  .page-about *{
    transition: none !important;
  }
}
<<<END>>>