.page-about {
  --ab-indent-l: clamp(0px, 5vw, 72px);
  --ab-indent-r: clamp(0px, 2vw, 24px);
  --ab-pad-x: clamp(20px, 4.6vw, 76px);
  --ab-pad-y: clamp(38px, 5.5vw, 88px);
  background:
    radial-gradient(1100px 520px at 84% -8%, rgba(34, 224, 200, .10), transparent 62%),
    radial-gradient(760px 420px at 8% 42%, rgba(255, 90, 31, .07), transparent 66%),
    var(--yb-deep);
  color: var(--yb-on-dark);
  font-family: var(--yb-font-body);
  overflow-x: clip;
  padding-bottom: clamp(40px, 6vw, 96px);
}

.page-about .ab-crumbbar {
  padding: clamp(20px, 4vw, 44px) var(--yb-gutter) 0;
  max-width: var(--yb-max);
  margin: 0 auto;
}

.page-about .yb-breadcrumb {
  font-size: 12px;
  letter-spacing: .12em;
  color: var(--yb-mist);
}

.page-about .yb-breadcrumb a {
  color: var(--yb-mist);
  text-decoration: none;
  border-bottom: 1px solid transparent;
  transition: color .24s var(--yb-ease), border-color .24s var(--yb-ease);
}

.page-about .yb-breadcrumb a:hover {
  color: var(--yb-cyan);
  border-bottom-color: var(--yb-cyan);
}

.page-about .ab-shell {
  display: grid;
  gap: clamp(14px, 2vw, 26px);
  margin-top: clamp(22px, 4vw, 52px);
}

.page-about .ab-sheet {
  position: relative;
  margin-left: var(--ab-indent-l);
  margin-right: var(--ab-indent-r);
  padding: var(--ab-pad-y) var(--ab-pad-x);
  border: 1px solid transparent;
}

.page-about .ab-sheet--stack {
  margin-left: calc(var(--ab-indent-l) + clamp(0px, 3.5vw, 46px));
}

.page-about .ab-sheet--paper {
  background: var(--yb-paper);
  color: var(--yb-on-paper);
  border-color: var(--yb-line-gold);
  clip-path: polygon(0 0, 100% 0, 100% calc(100% - 40px), calc(100% - 40px) 100%, 0 100%);
}

.page-about .ab-sheet--deep {
  background: linear-gradient(158deg, var(--yb-deep), var(--yb-ink));
  color: var(--yb-on-dark);
  border-color: var(--yb-line);
}

.page-about .ab-sheet--ink {
  background: var(--yb-ink);
  color: var(--yb-on-dark);
  border-color: var(--yb-line);
}

.page-about .ab-sheet--paper h2 { color: var(--yb-deep); }
.page-about .ab-sheet--deep h2,
.page-about .ab-sheet--ink h2 { color: var(--yb-paper); }

.page-about h2 {
  font-size: clamp(28px, 4.4vw, 60px);
  font-weight: 200;
  line-height: 1.08;
  letter-spacing: -.015em;
  margin: .2em 0 .5em;
}

.page-about h3 {
  font-size: clamp(17px, 1.9vw, 22px);
  font-weight: 700;
  letter-spacing: -.01em;
  margin: 0 0 .5em;
}

.page-about .ab-sheet--paper h3 { color: var(--yb-deep); }
.page-about .ab-sheet--deep h3,
.page-about .ab-sheet--ink h3 { color: var(--yb-paper); }

.page-about .ab-kicker {
  color: var(--yb-lava-dark);
  margin: 0;
}

.page-about .ab-kicker--dark { color: var(--yb-sand); }

.page-about .ab-lead {
  font-size: clamp(15px, 1.5vw, 18px);
  line-height: 1.78;
  max-width: 62ch;
  color: var(--yb-on-paper);
  margin: 0;
}

.page-about .ab-lead--dark { color: var(--yb-on-dark); }

.page-about p { line-height: 1.78; }

/* ---------- 01 品牌自述 ---------- */

.page-about .ab-hero__grid {
  display: grid;
  gap: clamp(30px, 4vw, 56px);
}

.page-about .ab-hero__title {
  font-size: clamp(34px, 9vw, 128px);
  font-weight: 200;
  line-height: .94;
  letter-spacing: -.02em;
  color: var(--yb-deep);
  margin: .12em 0 .22em;
}

.page-about .ab-hero__intro {
  font-size: clamp(15px, 1.6vw, 18px);
  line-height: 1.8;
  max-width: 52ch;
  color: var(--yb-on-paper);
  margin: 0 0 .9em;
}

.page-about .ab-stats {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 1px;
  background: var(--yb-line);
  border-top: 1px solid var(--yb-line-gold);
  border-bottom: 1px solid var(--yb-line-gold);
  margin: clamp(26px, 4vw, 44px) 0 0;
}

.page-about .ab-stats__item {
  background: var(--yb-paper);
  padding: 15px 14px;
  min-width: 0;
}

.page-about .ab-stats__l {
  font-size: 11px;
  letter-spacing: .18em;
  color: var(--yb-mist);
  margin: 0 0 6px;
}

.page-about .ab-stats__v {
  font-family: var(--yb-font-mono);
  font-variant-numeric: tabular-nums;
  font-size: clamp(20px, 2.6vw, 32px);
  line-height: 1.1;
  color: var(--yb-lava-dark);
  margin: 0;
}

.page-about .ab-stats__u {
  font-family: var(--yb-font-body);
  font-size: 12px;
  letter-spacing: .1em;
  color: var(--yb-mist);
  margin-left: 4px;
}

.page-about .ab-hero__figure .yb-figure__media {
  aspect-ratio: 3 / 4;
  overflow: hidden;
  border: 1px solid var(--yb-line-gold);
}

.page-about .ab-hero__figure .yb-figure__media img {
  width: 100%;
  height: 100%;
  object-fit: cover;
  display: block;
}

.page-about .yb-figure__cap {
  font-size: 12px;
  letter-spacing: .08em;
  color: var(--yb-mist);
  margin-top: 10px;
}

/* ---------- 02 资料体系 ---------- */

.page-about .ab-fields__head { max-width: 70ch; }

.page-about .ab-fields__grid {
  display: grid;
  gap: clamp(30px, 4vw, 56px);
  margin-top: clamp(28px, 4vw, 48px);
}

.page-about .ab-fields__main { min-width: 0; }

.page-about .ab-fieldgroup {
  padding-top: clamp(22px, 3vw, 34px);
  margin-top: clamp(22px, 3vw, 34px);
  border-top: 1px solid var(--yb-line);
  scroll-margin-top: 110px;
}

.page-about .ab-fieldgroup:first-child { border-top: 0; margin-top: 0; padding-top: 0; }

.page-about .ab-fieldgroup h3 {
  display: flex;
  align-items: baseline;
  gap: 12px;
  flex-wrap: wrap;
}

.page-about .ab-fieldgroup__tag {
  font-family: var(--yb-font-mono);
  font-variant-numeric: tabular-nums;
  font-size: 11px;
  letter-spacing: .16em;
  color: var(--yb-sand);
  border: 1px solid var(--yb-line-gold);
  padding: 2px 8px;
}

.page-about .ab-fieldgroup__note {
  font-size: 14px;
  color: var(--yb-on-paper-soft);
  margin: 0;
}

.page-about .ab-fieldlist {
  list-style: none;
  margin: .9em 0 0;
  padding: 0;
  display: grid;
  gap: 1px;
  background: var(--yb-line);
  border: 1px solid var(--yb-line);
}

.page-about .ab-fieldlist li {
  background: var(--yb-paper);
  padding: 14px 16px;
  transition: background .24s var(--yb-ease);
}

.page-about .ab-fieldlist li:hover { background: #EFE7DA; }

.page-about .ab-fieldlist b {
  display: block;
  font-size: 15px;
  color: var(--yb-deep);
  margin-bottom: 4px;
}

.page-about .ab-fieldlist span {
  font-size: 14px;
  line-height: 1.68;
  color: var(--yb-on-paper-soft);
}

.page-about .ab-fields__figure {
  margin: clamp(26px, 3.6vw, 42px) 0;
}

.page-about .ab-fields__figure .yb-figure__media {
  aspect-ratio: 3 / 2;
  overflow: hidden;
  border: 1px solid var(--yb-line-gold);
}

.page-about .ab-fields__figure .yb-figure__media img {
  width: 100%;
  height: 100%;
  object-fit: cover;
  display: block;
}

.page-about .ab-fields__aside { min-width: 0; }

.page-about .ab-indexcard {
  border: 1px solid var(--yb-line-gold);
  background: rgba(11, 30, 51, .04);
  padding: 22px 20px;
}

.page-about .ab-indexcard__title {
  color: var(--yb-lava-dark);
  margin: 0 0 14px;
}

.page-about .ab-indexcard__list {
  list-style: none;
  margin: 0;
  padding: 0;
  display: grid;
  gap: 1px;
  background: var(--yb-line);
  border-top: 1px solid var(--yb-line);
  border-bottom: 1px solid var(--yb-line);
}

.page-about .ab-indexcard__list li { background: var(--yb-paper); }

.page-about .ab-indexcard__list a {
  display: flex;
  align-items: baseline;
  gap: 12px;
  padding: 12px 6px;
  font-size: 15px;
  color: var(--yb-deep);
  text-decoration: none;
  border-left: 2px solid transparent;
  transition: color .24s var(--yb-ease), border-color .24s var(--yb-ease), padding-left .24s var(--yb-ease);
}

.page-about .ab-indexcard__list a:hover,
.page-about .ab-indexcard__list a:focus-visible {
  color: var(--yb-lava-dark);
  border-left-color: var(--yb-lava);
  padding-left: 12px;
}

.page-about .ab-indexcard__list .yb-num {
  font-family: var(--yb-font-mono);
  font-variant-numeric: tabular-nums;
  font-size: 12px;
  color: var(--yb-mist);
}

.page-about .ab-indexcard__note {
  font-size: 13px;
  line-height: 1.7;
  color: var(--yb-on-paper-soft);
  margin: 14px 0 0;
}

.page-about .ab-indexcard__note a {
  color: var(--yb-lava-dark);
  text-decoration: none;
  border-bottom: 1px solid var(--yb-line-gold);
  transition: color .24s var(--yb-ease), border-color .24s var(--yb-ease);
}

.page-about .ab-indexcard__note a:hover {
  color: var(--yb-deep);
  border-bottom-color: var(--yb-lava);
}

/* ---------- 03 团队与分工 ---------- */

.page-about .ab-team__grid {
  display: grid;
  gap: clamp(30px, 4vw, 56px);
}

.page-about .ab-team__visual {
  display: grid;
  gap: 18px;
  align-content: start;
}

.page-about .ab-compass {
  width: 100%;
  max-width: 300px;
  height: auto;
  display: block;
  margin: 0 auto;
}

.page-about .ab-team__body { min-width: 0; }

.page-about .ab-team__list {
  list-style: none;
  margin: clamp(26px, 3.4vw, 40px) 0 0;
  padding: 0;
  display: grid;
  gap: 1px;
  background: var(--yb-line);
  border: 1px solid var(--yb-line);
}

.page-about .ab-team__card {
  background: rgba(27, 62, 99, .34);
  padding: 20px 20px 22px;
  transition: background .24s var(--yb-ease), box-shadow .24s var(--yb-ease);
  position: relative;
}

.page-about .ab-team__card:hover {
  background: rgba(27, 62, 99, .62);
  box-shadow: inset 0 0 0 1px var(--yb-cyan);
}

.page-about .ab-team__no {
  font-family: var(--yb-font-mono);
  font-variant-numeric: tabular-nums;
  font-size: 12px;
  letter-spacing: .18em;
  color: var(--yb-sand);
  margin: 0 0 8px;
}

.page-about .ab-team__card p {
  font-size: 14.5px;
  line-height: 1.72;
  color: var(--yb-on-dark);
  margin: 0;
}

.page-about .ab-team__out {
  display: block;
  margin-top: 10px;
  padding-top: 10px;
  border-top: 1px solid var(--yb-line);
  font-size: 13px;
  letter-spacing: .04em;
  color: var(--yb-cyan);
}

/* ---------- 04 更新节奏 ---------- */

.page-about .ab-flow { overflow: hidden; }

.page-about .ab-flow__bg {
  position: absolute;
  inset: 0;
  pointer-events: none;
}

.page-about .ab-flow__bg::after {
  content: "";
  position: absolute;
  inset: 0;
  background: linear-gradient(180deg, rgba(8, 17, 28, .82), rgba(8, 17, 28, .94));
}

.page-about .ab-flow__bg img {
  width: 100%;
  height: 100%;
  object-fit: cover;
  opacity: .34;
  display: block;
}

.page-about .ab-flow__inner { position: relative; z-index: 1; }

.page-about .ab-timeline {
  list-style: none;
  margin: clamp(30px, 4vw, 52px) 0 0;
  padding: 0;
  display: grid;
  gap: clamp(26px, 3.4vw, 38px);
}

.page-about .ab-timeline__node {
  position: relative;
  padding-left: 26px;
  min-width: 0;
}

.page-about .ab-timeline__node::before {
  content: "";
  position: absolute;
  left: 5px;
  top: 18px;
  bottom: -26px;
  width: 1px;
  background: var(--yb-line);
}

.page-about .ab-timeline__node:last-child::before { display: none; }

.page-about .ab-timeline__dot {
  position: absolute;
  left: 0;
  top: 6px;
  width: 11px;
  height: 11px;
  border-radius: 50%;
  background: var(--yb-lava);
}

.page-about .ab-timeline__node--open .ab-timeline__dot {
  background: transparent;
  border: 2px solid var(--yb-lava);
}

.page-about .ab-timeline__when {
  font-family: var(--yb-font-mono);
  font-variant-numeric: tabular-nums;
  font-size: 12px;
  letter-spacing: .16em;
  color: var(--yb-cyan);
  margin: 0 0 8px;
}

.page-about .ab-timeline__node h3 { margin-bottom: .45em; }

.page-about .ab-timeline__node > p {
  font-size: 14.5px;
  line-height: 1.72;
  color: var(--yb-on-dark);
  margin: 0;
}

.page-about .ab-more { margin-top: 12px; }

.page-about .ab-more summary {
  cursor: pointer;
  list-style: none;
  font-size: 12px;
  letter-spacing: .14em;
  color: var(--yb-sand);
  border-bottom: 1px solid transparent;
  display: inline-block;
  transition: color .24s var(--yb-ease), border-color .24s var(--yb-ease);
}

.page-about .ab-more summary::-webkit-details-marker { display: none; }

.page-about .ab-more summary::before {
  content: "+";
  display: inline-block;
  width: 14px;
  font-family: var(--yb-font-mono);
}

.page-about .ab-more[open] summary::before { content: "\2212"; }

.page-about .ab-more summary:hover,
.page-about .ab-more summary:focus-visible {
  color: var(--yb-cyan);
  border-bottom-color: var(--yb-cyan);
}

.page-about .ab-more p {
  font-size: 13.5px;
  line-height: 1.72;
  color: var(--yb-on-dark-soft);
  margin: .8em 0 0;
  max-width: 40ch;
}

.page-about .ab-flow__foot {
  margin: clamp(28px, 3.6vw, 44px) 0 0;
  padding-top: 18px;
  border-top: 1px solid var(--yb-line);
  font-size: 14px;
  color: var(--yb-on-dark-soft);
}

.page-about .ab-flow__foot a {
  color: var(--yb-cyan);
  text-decoration: none;
  border-bottom: 1px solid rgba(34, 224, 200, .4);
  transition: border-color .24s var(--yb-ease);
}

.page-about .ab-flow__foot a:hover { border-bottom-color: var(--yb-cyan); }

/* ---------- 05 合作与信任 ---------- */

.page-about .ab-partner__grid {
  display: grid;
  gap: clamp(26px, 3.4vw, 44px);
  margin-top: clamp(24px, 3.2vw, 40px);
}

.page-about .ab-partner__col {
  border-top: 1px solid var(--yb-line-gold);
  padding-top: 20px;
  min-width: 0;
}

.page-about .ab-partner__col p {
  font-size: 14.5px;
  line-height: 1.76;
  color: var(--yb-on-paper);
  margin: 0 0 .8em;
}

.page-about .ab-partner__col a {
  color: var(--yb-lava-dark);
  text-decoration: none;
  border-bottom: 1px solid var(--yb-line-gold);
  transition: color .24s var(--yb-ease), border-color .24s var(--yb-ease);
}

.page-about .ab-partner__col a:hover {
  color: var(--yb-deep);
  border-bottom-color: var(--yb-lava);
}

.page-about .ab-copy {
  font-family: var(--yb-font-mono);
  font-size: 14px;
  color: var(--yb-deep);
  border-bottom: 1px dashed var(--yb-sand);
  word-break: break-all;
}

.page-about .ab-partner__note {
  font-size: 13px;
  color: var(--yb-on-paper-soft);
}

/* ---------- 06 收尾 ---------- */

.page-about .ab-cta__grid {
  display: grid;
  gap: clamp(24px, 3.4vw, 46px);
  align-items: end;
}

.page-about .ab-cta__links {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
}

.page-about .yb-cta {
  text-decoration: none;
  display: inline-block;
}

.page-about a:focus-visible,
.page-about summary:focus-visible {
  outline: 2px solid var(--yb-cyan);
  outline-offset: 3px;
}

/* ---------- 响应式 ---------- */

@media (min-width: 640px) {
  .page-about .ab-stats { grid-template-columns: repeat(3, minmax(0, 1fr)); }
  .page-about .ab-fieldlist { grid-template-columns: repeat(2, minmax(0, 1fr)); }
  .page-about .ab-team__list { grid-template-columns: repeat(2, minmax(0, 1fr)); }
  .page-about .ab-partner__grid { grid-template-columns: repeat(2, minmax(0, 1fr)); }
}

@media (min-width: 900px) {
  .page-about .ab-stats { grid-template-columns: repeat(5, minmax(0, 1fr)); }
  .page-about .ab-hero__grid {
    grid-template-columns: minmax(0, 1fr) minmax(240px, 340px);
    align-items: start;
  }
  .page-about .ab-team__grid {
    grid-template-columns: minmax(0, 320px) minmax(0, 1fr);
    align-items: start;
  }
  .page-about .ab-cta__grid {
    grid-template-columns: minmax(0, 1fr) minmax(0, auto);
  }
  .page-about .ab-cta__links { justify-content: flex-end; }
}

@media (min-width: 980px) {
  .page-about .ab-fields__grid {
    grid-template-columns: minmax(0, 1fr) minmax(250px, 318px);
    align-items: start;
  }
  .page-about .ab-indexcard {
    position: sticky;
    top: 104px;
  }
  .page-about .ab-fields__figure {
    width: 88%;
    margin-left: auto;
  }
  .page-about .ab-partner__grid { grid-template-columns: repeat(3, minmax(0, 1fr)); }
}

@media (min-width: 1020px) {
  .page-about .ab-timeline {
    grid-template-columns: repeat(4, minmax(0, 1fr));
    gap: clamp(14px, 1.8vw, 26px);
  }
  .page-about .ab-timeline__node {
    padding-left: 0;
    padding-top: 42px;
    padding-right: 6px;
  }
  .page-about .ab-timeline__node::before {
    left: 0;
    right: 0;
    top: 34px;
    bottom: auto;
    width: auto;
    height: 1px;
  }
  .page-about .ab-timeline__node:last-child::before { display: block; }
  .page-about .ab-timeline__dot {
    left: 0;
    top: 29px;
  }
}

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