.page-about{
  --ab-gap:clamp(20px,4vw,44px);
  --ab-pad:clamp(16px,4vw,40px);
  background:var(--yb-paper);
  color:var(--yb-ink-900);
  font-family:var(--yb-font);
}

.page-about .yb-crumbs{
  max-width:var(--yb-content);
  margin:0 auto;
  padding:18px var(--ab-pad) 14px;
}

/* 首屏 */
.page-about .ab-hero{
  position:relative;
  overflow:hidden;
  background:linear-gradient(135deg,var(--yb-indigo-900) 0%,var(--yb-indigo-700) 56%,var(--yb-indigo-500) 100%);
  color:#fff;
}
.page-about .ab-hero::before{
  content:"";
  position:absolute;
  top:-34%;
  right:-16%;
  width:78%;
  height:176%;
  background:linear-gradient(210deg,rgba(242,118,46,.42),rgba(47,143,123,.18) 58%,rgba(255,255,255,0) 80%);
  clip-path:polygon(40% 0,100% 0,100% 100%,0 100%);
  pointer-events:none;
}
.page-about .ab-hero::after{
  content:"";
  position:absolute;
  inset:0;
  background-image:
    linear-gradient(to right,rgba(255,255,255,.08) 1px,transparent 1px),
    linear-gradient(to bottom,rgba(255,255,255,.08) 1px,transparent 1px);
  background-size:72px 72px;
  -webkit-mask-image:linear-gradient(180deg,rgba(0,0,0,.55),transparent 72%);
  mask-image:linear-gradient(180deg,rgba(0,0,0,.55),transparent 72%);
  pointer-events:none;
}
.page-about .ab-hero__inner{
  position:relative;
  z-index:1;
  max-width:var(--yb-content);
  margin:0 auto;
  padding:clamp(30px,6vw,64px) var(--ab-pad) clamp(32px,6vw,60px);
}
.page-about .ab-hero__eyebrow{
  margin:0 0 14px;
  font-family:var(--yb-mono);
  font-size:12px;
  letter-spacing:.14em;
  color:var(--yb-orange-100);
}
.page-about .ab-hero h1{
  max-width:22ch;
  margin:0 0 18px;
  font-size:clamp(28px,6.2vw,58px);
  line-height:1.16;
  font-weight:900;
  letter-spacing:-.02em;
  color:#fff;
}
.page-about .ab-hero__lead{
  max-width:60ch;
  margin:0 0 26px;
  font-size:clamp(15px,2.2vw,17px);
  line-height:1.85;
  color:rgba(255,255,255,.86);
}
.page-about .ab-hero__meta{
  display:flex;
  flex-wrap:wrap;
  gap:10px 22px;
  margin:0;
  padding:16px 0 0;
  list-style:none;
  border-top:1px solid rgba(255,255,255,.22);
  font-size:13px;
  color:rgba(255,255,255,.78);
}
.page-about .ab-hero__meta li{display:flex;align-items:baseline;gap:7px}
.page-about .ab-hero__meta .yb-mono{
  font-size:14px;
  font-weight:700;
  color:var(--yb-orange-500);
}

/* 骨架 */
.page-about .ab-layout{
  display:grid;
  grid-template-columns:minmax(0,1fr);
  gap:var(--ab-gap);
  max-width:var(--yb-content);
  margin:0 auto;
  padding:clamp(26px,5vw,56px) var(--ab-pad) clamp(40px,7vw,80px);
}
.page-about .ab-index{
  border:1px solid var(--yb-line);
  border-radius:var(--yb-radius-lg);
  background:#fff;
  padding:14px 16px;
  box-shadow:var(--yb-shadow-1);
}
.page-about .ab-index__title{
  margin:0 0 10px;
  font-family:var(--yb-mono);
  font-size:12px;
  letter-spacing:.12em;
  color:var(--yb-ink-500);
}
.page-about .ab-index__list{
  display:flex;
  flex-wrap:wrap;
  gap:8px;
  margin:0;
  padding:0;
  list-style:none;
}
.page-about .ab-index__link{
  display:inline-flex;
  align-items:baseline;
  gap:7px;
  padding:6px 10px;
  border:1px solid var(--yb-line);
  border-radius:100px;
  font-size:13px;
  color:var(--yb-indigo-700);
  text-decoration:none;
  transition:background .18s var(--yb-ease),border-color .18s var(--yb-ease),transform .18s var(--yb-ease);
}
.page-about .ab-index__link .yb-mono{
  font-size:11px;
  color:var(--yb-orange-500);
}
.page-about .ab-index__link:hover,
.page-about .ab-index__link:focus-visible{
  background:var(--yb-indigo-100);
  border-color:var(--yb-indigo-500);
  transform:translateY(-1px);
}
.page-about .ab-index__link:focus-visible{
  outline:2px solid var(--yb-orange-500);
  outline-offset:2px;
}

.page-about .ab-flow{min-width:0}

/* 章节 */
.page-about .ab-sec{
  padding:clamp(22px,3.4vw,36px) 0 0;
  margin:0 0 clamp(22px,3.4vw,36px);
  border-top:1px solid var(--yb-line);
}
.page-about .ab-sec:first-child{border-top:0;padding-top:0}
.page-about .ab-sec__no{
  margin:0 0 8px;
  font-family:var(--yb-mono);
  font-size:12px;
  letter-spacing:.1em;
  color:var(--yb-orange-500);
}
.page-about .ab-sec__title{
  margin:0 0 16px;
  font-size:clamp(21px,3.4vw,29px);
  line-height:1.34;
  font-weight:800;
  letter-spacing:-.01em;
  color:var(--yb-indigo-700);
}
.page-about .ab-sec p{
  max-width:64ch;
  margin:0 0 14px;
  font-size:16px;
  line-height:1.85;
  color:var(--yb-ink-900);
}
.page-about .ab-sec p:last-child{margin-bottom:0}

/* 分栏 */
.page-about .ab-split{
  display:grid;
  grid-template-columns:minmax(0,1fr);
  gap:20px;
  margin-bottom:22px;
}
.page-about .ab-split__text{min-width:0}

/* 图 */
.page-about .ab-fig{
  margin:0;
  border:1px solid var(--yb-line);
  border-radius:var(--yb-radius-lg);
  overflow:hidden;
  background:var(--yb-indigo-100);
}
.page-about .ab-fig img{
  display:block;
  width:100%;
  height:auto;
  object-fit:cover;
}
.page-about .ab-fig figcaption{
  padding:10px 14px;
  background:#fff;
  border-top:1px solid var(--yb-line);
  font-family:var(--yb-mono);
  font-size:12px;
  line-height:1.65;
  color:var(--yb-ink-500);
}
.page-about .ab-fig--wide{margin-top:22px}

/* 玻璃注释卡 */
.page-about .ab-glass{
  position:relative;
  padding:20px 18px;
  border:1px solid rgba(255,255,255,.7);
  border-radius:var(--yb-radius-lg);
  background:linear-gradient(150deg,rgba(220,227,245,.9),rgba(255,255,255,.72));
  box-shadow:var(--yb-shadow-2);
  overflow:hidden;
}
.page-about .ab-glass::after{
  content:"";
  position:absolute;
  top:0;
  right:0;
  width:56px;
  height:56px;
  background:var(--yb-orange-500);
  opacity:.16;
  clip-path:polygon(100% 0,100% 100%,0 0);
}
.page-about .ab-glass__label{
  margin:0 0 10px;
  font-size:12px;
  letter-spacing:.1em;
  color:var(--yb-indigo-500);
}
.page-about .ab-glass p{
  margin:0;
  font-size:15px;
  line-height:1.8;
  color:var(--yb-indigo-700);
}

/* 数据条 */
.page-about .ab-stats{
  display:grid;
  grid-template-columns:repeat(2,minmax(0,1fr));
  gap:16px 12px;
  margin:0;
  padding:clamp(18px,3vw,30px);
  list-style:none;
  border-radius:var(--yb-radius-lg);
  background:linear-gradient(120deg,var(--yb-indigo-900),var(--yb-indigo-700) 60%,var(--yb-indigo-500));
  color:#fff;
}
.page-about .ab-stat{display:flex;flex-direction:column;gap:4px;min-width:0}
.page-about .ab-stat__num{
  font-size:clamp(22px,4vw,30px);
  font-weight:700;
  line-height:1.1;
  color:var(--yb-orange-500);
}
.page-about .ab-stat__label{
  font-size:12.5px;
  line-height:1.6;
  color:rgba(255,255,255,.8);
}

/* 时间轴 */
.page-about .ab-tl{
  position:relative;
  margin:20px 0 0;
  padding:0;
  list-style:none;
}
.page-about .ab-tl::before{
  content:"";
  position:absolute;
  left:5px;
  top:10px;
  bottom:10px;
  width:2px;
  background:linear-gradient(180deg,var(--yb-indigo-500),var(--yb-indigo-100));
}
.page-about .ab-tl__item{
  position:relative;
  padding:0 0 20px 26px;
}
.page-about .ab-tl__item::before{
  content:"";
  position:absolute;
  left:0;
  top:8px;
  width:12px;
  height:12px;
  border-radius:50%;
  background:#fff;
  border:2px solid var(--yb-indigo-500);
  transition:border-color .18s var(--yb-ease),background .18s var(--yb-ease);
}
.page-about .ab-tl__item:hover::before{
  border-color:var(--yb-orange-500);
  background:var(--yb-orange-100);
}
.page-about .ab-tl__year{
  display:inline-block;
  padding:3px 12px;
  margin-bottom:8px;
  font-size:12px;
  letter-spacing:.08em;
  color:var(--yb-indigo-700);
  background:var(--yb-indigo-100);
  clip-path:polygon(9px 0,100% 0,calc(100% - 9px) 100%,0 100%);
}
.page-about .ab-tl__title{
  margin:0 0 6px;
  font-size:17px;
  font-weight:700;
  line-height:1.5;
  color:var(--yb-ink-900);
}
.page-about .ab-tl__body p{
  margin:0 0 6px;
  font-size:15px;
  line-height:1.8;
  color:var(--yb-ink-500);
}
.page-about .ab-tl__more{
  font-size:13px;
  color:var(--yb-green-500);
}
.page-about .ab-tl__note{
  margin:18px 0 0;
  padding:14px 16px;
  border-left:3px solid var(--yb-orange-500);
  background:var(--yb-orange-100);
  border-radius:0 var(--yb-radius) var(--yb-radius) 0;
  font-size:15px;
  line-height:1.8;
  color:var(--yb-indigo-700);
  max-width:64ch;
}

/* 团队分工 */
.page-about .ab-roles{
  display:grid;
  grid-template-columns:minmax(0,1fr);
  gap:14px;
  margin:20px 0 0;
  padding:0;
  list-style:none;
}
.page-about .ab-role{
  position:relative;
  padding:18px 18px 16px;
  background:#fff;
  border:1px solid var(--yb-line);
  border-radius:var(--yb-radius-lg);
  min-width:0;
  transition:transform .18s var(--yb-ease),border-color .18s var(--yb-ease);
}
.page-about .ab-role:hover{
  transform:translateY(-2px);
  border-color:var(--yb-indigo-500);
}
.page-about .ab-role__code{
  margin:0 0 8px;
  font-size:12px;
  letter-spacing:.1em;
  color:var(--yb-green-500);
}
.page-about .ab-role__title{
  margin:0 0 8px;
  font-size:17px;
  font-weight:700;
  color:var(--yb-indigo-700);
}
.page-about .ab-role__text{
  margin:0;
  font-size:14.5px;
  line-height:1.8;
  color:var(--yb-ink-500);
}

/* 伙伴标签 */
.page-about .ab-tags{
  display:flex;
  flex-wrap:wrap;
  gap:10px;
  margin:18px 0 0;
  padding:0;
  list-style:none;
}
.page-about .ab-tag{
  position:relative;
  display:inline-block;
  padding:8px 14px;
  border:1px solid var(--yb-indigo-500);
  border-radius:var(--yb-radius);
  background:#fff;
  font-size:14px;
  color:var(--yb-indigo-700);
  transition:background .18s var(--yb-ease),color .18s var(--yb-ease);
}
.page-about .ab-tag:hover{
  background:var(--yb-indigo-700);
  color:#fff;
}
.page-about .ab-tag__tip{
  position:absolute;
  left:0;
  bottom:calc(100% + 8px);
  z-index:3;
  width:220px;
  max-width:60vw;
  padding:8px 10px;
  border-radius:var(--yb-radius);
  background:var(--yb-indigo-900);
  color:#fff;
  font-family:var(--yb-mono);
  font-size:11.5px;
  line-height:1.6;
  opacity:0;
  visibility:hidden;
  transform:translateY(4px);
  transition:opacity .18s var(--yb-ease),transform .18s var(--yb-ease),visibility .18s;
}
.page-about .ab-tag:hover .ab-tag__tip{
  opacity:1;
  visibility:visible;
  transform:translateY(0);
}

/* 下一步 */
.page-about .ab-sec--next{border-top:1px solid var(--yb-line)}
.page-about .ab-next{
  display:grid;
  grid-template-columns:minmax(0,1fr);
  gap:14px;
  margin:18px 0 24px;
  padding:0;
  list-style:none;
}
.page-about .ab-next__item{
  padding:16px 18px;
  border:1px solid var(--yb-line);
  border-left:3px solid var(--yb-indigo-500);
  border-radius:var(--yb-radius);
  background:#fff;
  min-width:0;
  transition:border-left-color .18s var(--yb-ease),transform .18s var(--yb-ease);
}
.page-about .ab-next__item:hover{
  border-left-color:var(--yb-orange-500);
  transform:translateY(-2px);
}
.page-about .ab-next__title{
  margin:0 0 6px;
  font-size:16.5px;
  font-weight:700;
  line-height:1.5;
}
.page-about .ab-next__link{
  color:var(--yb-indigo-700);
  text-decoration:none;
  border-bottom:1px solid var(--yb-line-strong);
}
.page-about .ab-next__link:hover{color:var(--yb-orange-600);border-bottom-color:var(--yb-orange-500)}
.page-about .ab-next__link:focus-visible{
  outline:2px solid var(--yb-orange-500);
  outline-offset:2px;
}
.page-about .ab-next__text{
  margin:0;
  font-size:14px;
  line-height:1.75;
  color:var(--yb-ink-500);
}

.page-about .ab-cta{
  display:grid;
  grid-template-columns:minmax(0,1fr);
  gap:16px;
  padding:clamp(18px,3vw,26px);
  border-radius:var(--yb-radius-lg);
  background:var(--yb-indigo-100);
  border:1px solid var(--yb-line-strong);
}
.page-about .ab-cta__title{
  margin:0 0 8px;
  font-size:17px;
  font-weight:700;
  color:var(--yb-indigo-700);
}
.page-about .ab-cta__line{
  margin:0 0 6px;
  font-size:13.5px;
  letter-spacing:.02em;
  color:var(--yb-ink-900);
  word-break:break-word;
}
.page-about .ab-cta__note{
  margin:0;
  font-size:13px;
  line-height:1.7;
  color:var(--yb-ink-500);
}
.page-about .ab-cta__btn{justify-self:start}

/* 平板与桌面 */
@media (min-width:760px){
  .page-about .ab-split{
    grid-template-columns:minmax(0,1.05fr) minmax(0,.95fr);
    align-items:start;
    gap:26px;
  }
  .page-about .ab-stats{grid-template-columns:repeat(5,minmax(0,1fr))}
  .page-about .ab-roles{grid-template-columns:repeat(3,minmax(0,1fr))}
  .page-about .ab-next{grid-template-columns:repeat(2,minmax(0,1fr))}
  .page-about .ab-cta{
    grid-template-columns:minmax(0,1fr) auto;
    align-items:center;
  }
  .page-about .ab-cta__btn{justify-self:end}
}

@media (min-width:960px){
  .page-about .ab-layout{
    grid-template-columns:216px minmax(0,1fr);
    gap:clamp(32px,4vw,56px);
    align-items:start;
  }
  .page-about .ab-index{
    position:sticky;
    top:24px;
    padding:18px 16px;
  }
  .page-about .ab-index__list{
    flex-direction:column;
    flex-wrap:nowrap;
    gap:4px;
  }
  .page-about .ab-index__link{
    width:100%;
    border-color:transparent;
    border-radius:var(--yb-radius);
    padding:8px 10px;
    border-left:2px solid transparent;
  }
  .page-about .ab-index__link:hover,
  .page-about .ab-index__link:focus-visible{
    background:var(--yb-indigo-100);
    border-color:transparent;
    border-left-color:var(--yb-orange-500);
    transform:none;
  }
  .page-about .ab-tl::before{left:7px}
  .page-about .ab-tl__item{padding-left:32px}
  .page-about .ab-tl__item::before{width:14px;height:14px}
  .page-about .ab-tl__more{
    max-height:0;
    overflow:hidden;
    opacity:0;
    transition:max-height .18s var(--yb-ease),opacity .18s var(--yb-ease),margin .18s var(--yb-ease);
    margin-bottom:0;
  }
  .page-about .ab-tl__item:hover .ab-tl__more,
  .page-about .ab-tl__item:focus-within .ab-tl__more{
    max-height:80px;
    opacity:1;
    margin-bottom:6px;
  }
}

@media (prefers-reduced-motion:reduce){
  .page-about *{
    transition-duration:.01ms !important;
    animation-duration:.01ms !important;
  }
}
<<<END>>>