.page-about {
  background: var(--yw-white);
  color: var(--yw-deep);
  overflow-x: hidden;
}

/* ============ 封面 ============ */
.page-about .ab-cover {
  position: relative;
  background: var(--yw-deep);
  color: var(--yw-white);
  padding: clamp(1.4rem, 4vw, 2.4rem) 0 clamp(2.2rem, 6vw, 3.6rem);
  overflow: hidden;
}

.page-about .ab-cover__dots {
  position: absolute;
  inset: 0;
  background-image: radial-gradient(rgba(31, 209, 209, .22) 1px, transparent 1px);
  background-size: 22px 22px;
  opacity: .55;
  pointer-events: none;
}

.page-about .ab-cover::after {
  content: "";
  position: absolute;
  left: 0;
  bottom: 0;
  width: 100%;
  height: 6px;
  background: linear-gradient(90deg, var(--yw-orange), var(--yw-cyan) 55%, var(--yw-purple));
  pointer-events: none;
}

.page-about .ab-crumbs {
  position: relative;
  z-index: 2;
  margin-bottom: clamp(1.4rem, 4vw, 2.6rem);
}

.page-about .ab-cover .yw-crumbs__link {
  color: var(--yw-cyan);
}

.page-about .ab-cover .yw-crumbs__sep {
  color: rgba(108, 126, 153, .8);
}

.page-about .ab-cover .yw-crumbs__current {
  color: var(--yw-white);
}

.page-about .ab-cover__body {
  position: relative;
  z-index: 2;
  display: grid;
  grid-template-columns: 1fr;
  gap: clamp(1rem, 3vw, 2rem);
}

.page-about .ab-cover__rail {
  display: none;
  flex-direction: column;
  align-items: center;
  gap: .9rem;
}

.page-about .ab-cover__railnum {
  font-family: var(--yw-mono);
  font-size: 1.05rem;
  letter-spacing: .12em;
  color: var(--yw-orange);
}

.page-about .ab-cover__railline {
  flex: 1 1 auto;
  width: 1px;
  min-height: 110px;
  background: linear-gradient(to bottom, var(--yw-orange), rgba(255, 106, 26, 0));
}

.page-about .ab-cover__railword {
  writing-mode: vertical-rl;
  font-size: .92rem;
  letter-spacing: .48em;
  color: rgba(246, 242, 230, .45);
}

.page-about .ab-cover__eyebrow {
  margin: 0;
  font-family: var(--yw-mono);
  font-size: .74rem;
  letter-spacing: .2em;
  color: var(--yw-cyan);
  text-transform: uppercase;
}

.page-about .ab-cover__title {
  margin: .9rem 0 0;
  font-size: clamp(2.3rem, 7vw, 5.4rem);
  font-weight: 200;
  line-height: 1.04;
  letter-spacing: -.02em;
  color: var(--yw-white);
}

.page-about .ab-cover__title em {
  font-style: normal;
  font-weight: 800;
  color: var(--yw-orange);
  text-shadow: 3px 3px 0 rgba(18, 60, 116, .9);
}

.page-about .ab-cover__lede {
  margin: clamp(1.1rem, 3vw, 1.7rem) 0 0;
  max-width: 64ch;
  font-size: clamp(1rem, 1.6vw, 1.1rem);
  line-height: 1.85;
  color: rgba(246, 242, 230, .74);
}

.page-about .ab-cover__actions {
  display: flex;
  flex-wrap: wrap;
  gap: .75rem;
  margin-top: clamp(1.3rem, 3.5vw, 2rem);
}

.page-about .ab-stats {
  position: relative;
  z-index: 2;
  list-style: none;
  margin: clamp(2rem, 5.5vw, 3.4rem) 0 0;
  padding: 0;
  display: grid;
  grid-template-columns: 1fr;
  gap: 1px;
  background: rgba(246, 242, 230, .16);
  border: 1px solid rgba(246, 242, 230, .16);
  border-radius: 4px;
  overflow: hidden;
}

.page-about .ab-stat {
  background: var(--yw-deep);
  padding: clamp(1.1rem, 2.8vw, 1.6rem);
}

.page-about .ab-stat__num {
  display: block;
  font-size: clamp(1.9rem, 5vw, 2.9rem);
  font-weight: 200;
  line-height: 1;
  letter-spacing: -.02em;
  color: var(--yw-yellow);
}

.page-about .ab-stat__unit {
  font-size: .48em;
  font-weight: 400;
  color: rgba(246, 242, 230, .8);
}

.page-about .ab-stat__label {
  display: block;
  margin-top: .6rem;
  font-size: .85rem;
  line-height: 1.65;
  color: rgba(246, 242, 230, .62);
}

/* ============ 章节骨架 ============ */
.page-about .ab-sec {
  position: relative;
  padding: clamp(2.6rem, 7vw, 5.2rem) 0;
}

.page-about .ab-sec--paper { background: var(--yw-white); }
.page-about .ab-sec--sand  { background: var(--yw-paper); }
.page-about .ab-sec--blue  { background: var(--yw-blue); color: var(--yw-white); }
.page-about .ab-sec--ink   { background: var(--yw-deep); color: var(--yw-white); }

.page-about .ab-block {
  display: grid;
  grid-template-columns: 1fr;
  gap: clamp(1rem, 3vw, 2rem);
}

.page-about .ab-block__rail {
  display: flex;
  align-items: center;
  gap: .7rem;
}

.page-about .ab-num {
  font-family: var(--yw-mono);
  font-size: clamp(1.5rem, 3.4vw, 2.3rem);
  font-weight: 700;
  line-height: 1;
  color: var(--yw-orange);
}

.page-about .ab-railtag {
  font-family: var(--yw-mono);
  font-size: .7rem;
  letter-spacing: .24em;
  text-transform: uppercase;
  color: var(--yw-slate);
}

.page-about .ab-sec--blue .ab-railtag,
.page-about .ab-sec--ink .ab-railtag {
  color: rgba(246, 242, 230, .5);
}

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

.page-about .ab-h2 {
  margin: 0 0 clamp(.8rem, 2vw, 1.1rem);
  font-size: clamp(1.5rem, 3.4vw, 2.45rem);
  font-weight: 800;
  line-height: 1.28;
  letter-spacing: -.01em;
  color: var(--yw-deep);
  text-shadow: 4px 4px 0 rgba(18, 60, 116, .13);
}

.page-about .ab-sec--blue .ab-h2,
.page-about .ab-sec--ink .ab-h2 {
  color: var(--yw-white);
  text-shadow: 4px 4px 0 rgba(8, 24, 46, .6);
}

.page-about .ab-lede {
  margin: 0;
  max-width: 66ch;
  font-size: clamp(1rem, 1.5vw, 1.06rem);
  line-height: 1.85;
  color: rgba(8, 24, 46, .76);
}

.page-about .ab-sec--blue .ab-lede,
.page-about .ab-sec--ink .ab-lede {
  color: rgba(246, 242, 230, .76);
}

/* ============ 六维评分 ============ */
.page-about .ab-score {
  margin-top: clamp(1.6rem, 4vw, 2.6rem);
  display: grid;
  grid-template-columns: 1fr;
  gap: clamp(1.2rem, 4vw, 2.4rem);
}

.page-about .ab-score__chart {
  background: var(--yw-paper);
  border: 2px solid var(--yw-deep);
  border-radius: 4px;
  box-shadow: var(--yw-shadow);
  padding: clamp(.7rem, 2vw, 1.15rem);
}

.page-about .ab-score__chart svg {
  display: block;
  width: 100%;
  height: auto;
}

.page-about .ab-score__list {
  list-style: none;
  margin: 0;
  padding: 0;
  display: grid;
  gap: .8rem;
}

.page-about .ab-score__item {
  display: grid;
  grid-template-columns: 1fr auto;
  align-items: baseline;
  gap: .4rem .75rem;
  padding: .85rem 1rem;
  background: var(--yw-white);
  border: 2px solid rgba(8, 24, 46, .14);
  border-radius: 4px;
  transition: border-color var(--yw-dur) var(--yw-ease),
              transform var(--yw-dur) var(--yw-ease),
              box-shadow var(--yw-dur) var(--yw-ease);
}

.page-about .ab-score__item:hover,
.page-about .ab-score__item:focus-within {
  border-color: var(--yw-orange);
  transform: translateY(-3px);
  box-shadow: 0 6px 0 rgba(8, 24, 46, .1);
}

.page-about .ab-score__name {
  font-weight: 700;
  font-size: 1rem;
  color: var(--yw-deep);
}

.page-about .ab-score__val {
  font-family: var(--yw-mono);
  font-size: 1.05rem;
  font-weight: 700;
  color: var(--yw-orange);
}

.page-about .ab-score__bar {
  grid-column: 1 / -1;
  display: block;
  height: 6px;
  border-radius: 999px;
  background: rgba(8, 24, 46, .1);
  overflow: hidden;
}

.page-about .ab-score__bar i {
  display: block;
  height: 100%;
  border-radius: inherit;
  background: linear-gradient(90deg, var(--yw-cyan), var(--yw-orange));
}

.page-about .ab-score__note {
  grid-column: 1 / -1;
  display: block;
  font-size: .83rem;
  line-height: 1.65;
  color: var(--yw-slate);
  max-height: 0;
  opacity: 0;
  overflow: hidden;
  transition: max-height 220ms var(--yw-ease),
              opacity 220ms var(--yw-ease),
              margin-top 220ms var(--yw-ease);
}

.page-about .ab-score__item:hover .ab-score__note,
.page-about .ab-score__item:focus-within .ab-score__note {
  max-height: 8rem;
  opacity: 1;
  margin-top: .35rem;
}

/* ============ 团队工作线 ============ */
.page-about .ab-shot {
  margin: clamp(1.5rem, 4vw, 2.4rem) 0 0;
  max-width: 720px;
}

.page-about .ab-shot__frame {
  border: 2px solid var(--yw-white);
  border-radius: 4px;
  overflow: hidden;
  background: var(--yw-deep);
  box-shadow: 8px 8px 0 rgba(8, 24, 46, .42);
}

.page-about .ab-shot__frame img {
  display: block;
  width: 100%;
  height: auto;
  aspect-ratio: 3 / 2;
  object-fit: cover;
}

.page-about .ab-shot__cap {
  margin-top: .8rem;
  font-size: .84rem;
  line-height: 1.65;
  color: rgba(246, 242, 230, .62);
}

.page-about .ab-lines {
  list-style: none;
  margin: clamp(1.5rem, 4vw, 2.4rem) 0 0;
  padding: 0;
  display: grid;
  grid-template-columns: 1fr;
  gap: 1rem;
}

.page-about .ab-line {
  position: relative;
  padding: 1.2rem 1.1rem 1.3rem;
  background: rgba(246, 242, 230, .07);
  border: 1px solid rgba(246, 242, 230, .2);
  border-radius: 4px;
  transition: border-color var(--yw-dur) var(--yw-ease),
              background var(--yw-dur) var(--yw-ease);
}

.page-about .ab-line:hover {
  border-color: var(--yw-cyan);
  background: rgba(31, 209, 209, .1);
}

.page-about .ab-line__idx {
  display: inline-block;
  font-family: var(--yw-mono);
  font-size: .72rem;
  letter-spacing: .16em;
  color: var(--yw-deep);
  background: var(--yw-yellow);
  padding: .12rem .42rem;
  border-radius: 2px;
}

.page-about .ab-line__title {
  margin: .7rem 0 .45rem;
  font-size: 1.16rem;
  font-weight: 800;
  color: var(--yw-white);
}

.page-about .ab-line__desc {
  margin: 0;
  font-size: .92rem;
  line-height: 1.75;
  color: rgba(246, 242, 230, .72);
}

/* ============ 时间轴 ============ */
.page-about .ab-tlart {
  margin: clamp(1.4rem, 4vw, 2.2rem) 0 0;
}

.page-about .ab-tlart img {
  display: block;
  width: 100%;
  height: auto;
  aspect-ratio: 5 / 3;
  object-fit: cover;
  border: 2px solid var(--yw-deep);
  border-radius: 4px;
  box-shadow: 6px 6px 0 rgba(8, 24, 46, .14);
}

.page-about .ab-tl {
  margin-top: clamp(1.6rem, 4vw, 2.4rem);
}

.page-about .ab-tl__list {
  display: flex;
  flex-wrap: wrap;
  gap: .55rem;
  margin-bottom: 1.25rem;
}

.page-about .ab-tl__btn {
  display: inline-flex;
  flex-direction: column;
  gap: .12rem;
  padding: .6rem 1rem;
  font: inherit;
  text-align: left;
  color: var(--yw-deep);
  background: var(--yw-white);
  border: 2px solid var(--yw-deep);
  border-radius: 3px;
  box-shadow: 3px 3px 0 rgba(8, 24, 46, .16);
  cursor: pointer;
  transition: transform var(--yw-dur) var(--yw-ease),
              box-shadow var(--yw-dur) var(--yw-ease),
              background var(--yw-dur) var(--yw-ease),
              color var(--yw-dur) var(--yw-ease);
}

.page-about .ab-tl__btn:nth-child(2n) { transform: rotate(.9deg); }
.page-about .ab-tl__btn:nth-child(3n) { transform: rotate(-.7deg); }

.page-about .ab-tl__btn:hover {
  transform: translateY(-3px);
  box-shadow: 4px 5px 0 rgba(8, 24, 46, .24);
}

.page-about .ab-tl__btn[aria-selected="true"] {
  background: var(--yw-orange);
  color: var(--yw-deep);
  transform: translateY(-4px);
  box-shadow: 5px 6px 0 rgba(8, 24, 46, .28);
}

.page-about .ab-tl__yr {
  font-family: var(--yw-mono);
  font-size: .66rem;
  letter-spacing: .16em;
  opacity: .72;
}

.page-about .ab-tl__nm {
  font-size: .96rem;
  font-weight: 800;
  letter-spacing: .02em;
}

.page-about .ab-tl__panel {
  background: var(--yw-white);
  border: 2px solid var(--yw-deep);
  border-radius: 4px;
  box-shadow: var(--yw-shadow);
  padding: clamp(1.1rem, 3vw, 1.8rem);
}

.page-about .ab-tl__head {
  margin: 0 0 .8rem;
  font-size: clamp(1.1rem, 2.2vw, 1.36rem);
  font-weight: 800;
  color: var(--yw-deep);
}

.page-about .ab-tl__panel p {
  margin: 0 0 .8rem;
  font-size: .96rem;
  line-height: 1.85;
  color: rgba(8, 24, 46, .76);
}

.page-about .ab-tl__panel p:last-child {
  margin-bottom: 0;
}

/* ============ 合作生态 ============ */
.page-about .ab-collab {
  margin-top: clamp(1.5rem, 4vw, 2.4rem);
  display: grid;
  grid-template-columns: 1fr;
  gap: clamp(1.3rem, 4vw, 2.4rem);
}

.page-about .ab-collab__art {
  margin: 0;
}

.page-about .ab-collab__frame {
  border: 2px solid var(--yw-deep);
  border-radius: 4px;
  overflow: hidden;
  box-shadow: 6px 6px 0 rgba(8, 24, 46, .14);
  background: var(--yw-paper);
}

.page-about .ab-collab__frame img {
  display: block;
  width: 100%;
  height: auto;
  aspect-ratio: 3 / 2;
  object-fit: cover;
}

.page-about .ab-collab__list {
  list-style: none;
  margin: 0;
  padding: 0;
  display: grid;
  gap: .9rem;
}

.page-about .ab-collab__item {
  padding-left: 1rem;
  border-left: 4px solid var(--yw-cyan);
}

.page-about .ab-collab__title {
  margin: 0 0 .35rem;
  font-size: 1.06rem;
  font-weight: 800;
  color: var(--yw-deep);
}

.page-about .ab-collab__item p {
  margin: 0;
  font-size: .93rem;
  line-height: 1.78;
  color: rgba(8, 24, 46, .72);
}

.page-about .ab-collab__foot {
  margin: 1.2rem 0 0;
  padding: .95rem 1.1rem;
  font-size: .93rem;
  line-height: 1.78;
  color: var(--yw-deep);
  background: rgba(255, 210, 74, .32);
  border: 2px dashed rgba(8, 24, 46, .28);
  border-radius: 4px;
}

/* ============ 社区与更新承诺 ============ */
.page-about .ab-figures {
  margin: clamp(1.5rem, 4vw, 2.2rem) 0;
  display: grid;
  grid-template-columns: 1fr;
  gap: 1px;
  background: rgba(246, 242, 230, .18);
  border: 1px solid rgba(246, 242, 230, .18);
  border-radius: 4px;
  overflow: hidden;
}

.page-about .ab-fig {
  background: var(--yw-deep);
  padding: clamp(1rem, 2.6vw, 1.4rem);
}

.page-about .ab-fig__n {
  display: block;
  font-size: clamp(1.6rem, 4vw, 2.3rem);
  font-weight: 200;
  line-height: 1;
  letter-spacing: -.01em;
  color: var(--yw-cyan);
}

.page-about .ab-fig__l {
  display: block;
  margin-top: .55rem;
  font-size: .84rem;
  line-height: 1.65;
  color: rgba(246, 242, 230, .64);
}

.page-about .ab-promise {
  list-style: none;
  margin: 0;
  padding: 0;
  display: grid;
  gap: 1px;
  background: rgba(246, 242, 230, .16);
  border: 1px solid rgba(246, 242, 230, .16);
  border-radius: 4px;
  overflow: hidden;
}

.page-about .ab-promise__item {
  display: grid;
  grid-template-columns: 1fr;
  gap: .3rem;
  background: var(--yw-deep);
  padding: .95rem clamp(.9rem, 2.4vw, 1.3rem);
}

.page-about .ab-promise__key {
  font-family: var(--yw-mono);
  font-size: .82rem;
  letter-spacing: .06em;
  color: var(--yw-orange);
}

.page-about .ab-promise__val {
  font-size: .94rem;
  line-height: 1.7;
  color: rgba(246, 242, 230, .82);
}

.page-about .ab-cta {
  margin-top: clamp(1.5rem, 4vw, 2.2rem);
  padding: clamp(1.1rem, 3vw, 1.7rem);
  border: 2px solid rgba(246, 242, 230, .24);
  border-radius: 20px;
  background: rgba(18, 60, 116, .58);
}

.page-about .ab-cta__text {
  margin: 0 0 1rem;
  font-size: .97rem;
  line-height: 1.8;
  color: rgba(246, 242, 230, .8);
}

.page-about .ab-cta__row {
  display: flex;
  flex-wrap: wrap;
  gap: .75rem;
}

/* ============ 响应式 ============ */
@media (min-width: 700px) {
  .page-about .ab-stats {
    grid-template-columns: repeat(3, 1fr);
  }

  .page-about .ab-lines {
    grid-template-columns: repeat(2, 1fr);
  }

  .page-about .ab-figures {
    grid-template-columns: repeat(3, 1fr);
  }

  .page-about .ab-promise__item {
    grid-template-columns: 11rem minmax(0, 1fr);
    align-items: baseline;
    gap: 1rem;
  }
}

@media (min-width: 880px) {
  .page-about .ab-cover__body {
    grid-template-columns: 88px minmax(0, 1fr);
    align-items: start;
  }

  .page-about .ab-cover__rail {
    display: flex;
    align-self: stretch;
  }

  .page-about .ab-block {
    grid-template-columns: 96px minmax(0, 1fr);
    gap: clamp(1.5rem, 3vw, 2.5rem);
  }

  .page-about .ab-block__rail {
    flex-direction: column;
    align-items: flex-start;
    gap: .55rem;
    padding-top: .3rem;
  }

  .page-about .ab-block__main {
    padding-left: clamp(0rem, 1.6vw, 1.5rem);
  }

  .page-about .ab-score {
    grid-template-columns: minmax(0, 300px) minmax(0, 1fr);
    align-items: center;
  }

  .page-about .ab-collab {
    grid-template-columns: minmax(0, 420px) minmax(0, 1fr);
    align-items: start;
  }

  .page-about .ab-collab__art {
    position: sticky;
    top: 6.5rem;
  }
}

@media (min-width: 1100px) {
  .page-about .ab-score {
    grid-template-columns: minmax(0, 340px) minmax(0, 1fr);
  }
}

@media (hover: none) {
  .page-about .ab-score__note {
    max-height: 8rem;
    opacity: 1;
    margin-top: .35rem;
  }
}

@media (prefers-reduced-motion: reduce) {
  .page-about .ab-score__item,
  .page-about .ab-line,
  .page-about .ab-tl__btn {
    transition: none;
  }

  .page-about .ab-score__item:hover,
  .page-about .ab-score__item:focus-within,
  .page-about .ab-tl__btn:hover,
  .page-about .ab-tl__btn[aria-selected="true"] {
    transform: none;
  }
}