.page-about {
  background: var(--ink);
  color: var(--chalk);
}

.page-about .ab-h2 {
  font-size: clamp(26px, 4.4vw, 44px);
  font-weight: 300;
  line-height: 1.16;
  letter-spacing: -0.02em;
  margin: 10px 0 0;
}

.page-about .ab-lead {
  margin: 16px 0 0;
  max-width: 58ch;
  font-size: 15px;
  line-height: 1.8;
}

/* ---------- 封面 ---------- */
.page-about .ab-cover {
  position: relative;
  overflow: hidden;
  padding: clamp(20px, 4vw, 40px) 0 clamp(48px, 7vw, 92px);
  background:
    radial-gradient(120% 90% at 88% -10%, rgba(53, 240, 208, 0.16), transparent 62%),
    radial-gradient(90% 70% at 0% 100%, rgba(255, 122, 61, 0.1), transparent 60%),
    var(--ink);
}

.page-about .ab-cover::before {
  content: "";
  position: absolute;
  inset: 0;
  pointer-events: none;
  background-image:
    repeating-linear-gradient(90deg, rgba(53, 240, 208, 0.07) 0 1px, transparent 1px 108px),
    repeating-linear-gradient(0deg, rgba(53, 240, 208, 0.05) 0 1px, transparent 1px 108px);
  -webkit-mask-image: linear-gradient(180deg, #000 0%, transparent 82%);
  mask-image: linear-gradient(180deg, #000 0%, transparent 82%);
}

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

.page-about .breadcrumb {
  display: flex;
  align-items: center;
  gap: 8px;
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.06em;
  color: var(--paper-dim);
}

.page-about .breadcrumb a {
  color: var(--cyan);
  text-decoration: none;
}

.page-about .breadcrumb a:hover {
  color: var(--chalk);
}

.page-about .breadcrumb__sep {
  color: rgba(207, 195, 168, 0.5);
}

.page-about .eyebrow {
  margin: 24px 0 0;
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.24em;
  text-transform: uppercase;
  color: var(--cyan);
}

.page-about .ab-cover__grid {
  display: grid;
  gap: clamp(26px, 4vw, 44px);
  margin-top: 10px;
}

.page-about .ab-cover__title {
  margin: 12px 0 0;
  font-size: clamp(34px, 8vw, 84px);
  font-weight: 300;
  line-height: 1.07;
  letter-spacing: -0.035em;
  transform: skewX(-2.5deg);
  transform-origin: left bottom;
}

.page-about .ab-cover__title .num {
  color: var(--cyan);
  font-style: normal;
}

.page-about .ab-cover__lede {
  margin: 20px 0 0;
  max-width: 52ch;
  font-size: 16px;
  line-height: 1.8;
  color: rgba(247, 245, 239, 0.86);
}

.page-about .ab-cover__lede--dim {
  margin-top: 12px;
  font-size: 14px;
  color: var(--paper-dim);
}

.page-about .ab-stats {
  display: grid;
  gap: 10px;
  margin-top: clamp(22px, 3.5vw, 32px);
}

.page-about .ab-stat {
  display: block;
  padding: 16px 18px 15px;
  text-decoration: none;
  color: var(--chalk);
  border: 1px solid rgba(53, 240, 208, 0.26);
  background: rgba(12, 42, 33, 0.66);
  clip-path: polygon(0 0, calc(100% - 16px) 0, 100% 16px, 100% 100%, 16px 100%, 0 calc(100% - 16px));
  transition: border-color 0.2s var(--ease), transform 0.2s var(--ease), background 0.2s var(--ease);
}

.page-about .ab-stat:hover,
.page-about .ab-stat:focus-visible {
  border-color: var(--cyan);
  background: rgba(20, 82, 63, 0.72);
  transform: translateY(-3px);
}

.page-about .ab-stat__num {
  display: block;
  font-family: var(--font-mono);
  font-size: clamp(30px, 5.4vw, 40px);
  line-height: 1;
  color: var(--cyan);
  letter-spacing: -0.02em;
}

.page-about .ab-stat__num em {
  font-style: normal;
  color: var(--orange);
  font-size: 0.6em;
  margin-left: 1px;
}

.page-about .ab-stat__label {
  display: block;
  margin-top: 9px;
  font-size: 13px;
  line-height: 1.6;
  color: var(--paper-dim);
}

.page-about .ab-stat__go {
  display: inline-block;
  margin-top: 10px;
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: 0.1em;
  color: var(--orange);
}

.page-about .ab-cover__actions {
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
  margin-top: clamp(22px, 3.5vw, 30px);
}

.page-about .ab-cover__figure {
  position: relative;
  margin: 0;
  clip-path: polygon(0 0, 100% 0, 100% calc(100% - 34px), calc(100% - 34px) 100%, 0 100%);
  background: var(--deep);
}

.page-about .ab-cover__figure img {
  display: block;
  width: 100%;
  height: auto;
  max-width: 100%;
  object-fit: cover;
}

.page-about .ab-cover__figure::after {
  content: "";
  position: absolute;
  inset: 14px 14px auto 14px;
  height: 34%;
  border: 1px solid rgba(53, 240, 208, 0.5);
  clip-path: polygon(0 0, 100% 0, 100% 100%, calc(100% - 14px) 100%, 0 calc(100% - 14px));
  pointer-events: none;
}

.page-about .ab-cover__cap {
  position: absolute;
  left: 14px;
  bottom: 12px;
  font-family: var(--font-mono);
  font-size: 10px;
  letter-spacing: 0.18em;
  color: rgba(247, 245, 239, 0.75);
}

/* ---------- 时间线 ---------- */
.page-about .ab-time {
  position: relative;
  padding: clamp(46px, 7vw, 92px) 0 clamp(46px, 7vw, 88px);
  background: var(--deep);
  border-top: 1px solid rgba(53, 240, 208, 0.16);
}

.page-about .ab-time .ab-lead {
  color: var(--paper-dim);
}

.page-about .ab-timeline {
  list-style: none;
  margin: clamp(26px, 4vw, 44px) 0 0;
  padding: 0;
  position: relative;
}

.page-about .ab-timeline::before {
  content: "";
  position: absolute;
  left: 7px;
  top: 8px;
  bottom: 8px;
  width: 2px;
  background: linear-gradient(180deg, var(--cyan), var(--line) 55%, rgba(20, 82, 63, 0.18));
}

.page-about .ab-timeline__item {
  position: relative;
  padding: 0 0 clamp(26px, 4vw, 38px) 34px;
  outline-offset: 4px;
}

.page-about .ab-timeline__item:last-child {
  padding-bottom: 0;
}

.page-about .ab-timeline__item::before {
  content: "";
  position: absolute;
  left: 0;
  top: 4px;
  width: 16px;
  height: 16px;
  box-sizing: border-box;
  border: 2px solid var(--cyan);
  border-radius: 50%;
  background: var(--deep);
  transition: background 0.2s var(--ease), box-shadow 0.2s var(--ease);
}

.page-about .ab-timeline__item:hover::before,
.page-about .ab-timeline__item:focus::before {
  background: var(--cyan);
  box-shadow: 0 0 0 5px rgba(53, 240, 208, 0.16);
}

.page-about .ab-timeline__year {
  display: block;
  font-family: var(--font-mono);
  font-size: 13px;
  letter-spacing: 0.18em;
  color: var(--cyan);
  margin-bottom: 4px;
}

.page-about .ab-timeline__body h3 {
  margin: 4px 0 8px;
  font-size: clamp(19px, 2.6vw, 24px);
  font-weight: 600;
  line-height: 1.3;
  color: var(--chalk);
}

.page-about .ab-timeline__body p {
  margin: 0 0 8px;
  max-width: 62ch;
  font-size: 15px;
  line-height: 1.78;
  color: var(--paper-dim);
}

.page-about .ab-timeline__extra {
  overflow: hidden;
  max-height: none;
  opacity: 1;
}

.page-about .ab-timeline__meta {
  margin: 0;
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.06em;
  color: var(--cyan);
}

.page-about .ab-time__figure {
  margin: clamp(30px, 5vw, 52px) 0 0;
  position: relative;
}

.page-about .ab-time__figure img {
  display: block;
  width: 100%;
  height: auto;
  max-width: 100%;
  object-fit: cover;
  clip-path: polygon(0 0, 100% 0, 100% 100%, 28px 100%, 0 calc(100% - 28px));
}

.page-about .ab-time__figure figcaption {
  margin-top: 12px;
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: 0.08em;
  color: var(--paper-dim);
}

/* ---------- 团队（暖纸） ---------- */
.page-about .ab-team {
  position: relative;
  padding: clamp(56px, 8vw, 104px) 0 clamp(48px, 7vw, 88px);
  background: var(--paper);
  color: var(--black);
}

.page-about .ab-team::before {
  content: "";
  position: absolute;
  left: 0;
  right: 0;
  top: 0;
  height: clamp(26px, 6vw, 64px);
  background: var(--deep);
  clip-path: polygon(0 0, 100% 0, 0 100%);
  pointer-events: none;
}

.page-about .ab-team .eyebrow {
  color: var(--orange-ink);
}

.page-about .ab-team .ab-lead {
  color: rgba(16, 25, 21, 0.78);
}

.page-about .ab-team__figure {
  margin: clamp(24px, 4vw, 38px) 0 0;
}

.page-about .ab-team__figure img {
  display: block;
  width: 100%;
  height: auto;
  max-width: 100%;
  object-fit: cover;
  clip-path: polygon(0 0, 100% 0, 100% calc(100% - 26px), calc(100% - 26px) 100%, 0 100%);
}

.page-about .ab-team__grid {
  display: grid;
  gap: 12px;
  margin-top: clamp(22px, 3.6vw, 34px);
}

.page-about .ab-role {
  padding: 18px 20px 20px;
  background: rgba(247, 245, 239, 0.82);
  border: 1px solid var(--paper-dim);
  clip-path: polygon(0 0, calc(100% - 18px) 0, 100% 18px, 100% 100%, 0 100%);
}

.page-about .ab-role__num {
  display: block;
  font-family: var(--font-mono);
  font-size: 30px;
  line-height: 1;
  letter-spacing: -0.02em;
  color: var(--orange-ink);
}

.page-about .ab-role__name {
  margin: 10px 0 8px;
  font-size: 16px;
  font-weight: 600;
  color: var(--black);
}

.page-about .ab-role__desc {
  margin: 0;
  font-size: 14px;
  line-height: 1.75;
  color: rgba(16, 25, 21, 0.76);
}

/* ---------- 覆盖与合作 ---------- */
.page-about .ab-eco {
  position: relative;
  padding: clamp(56px, 8vw, 104px) 0 clamp(48px, 7vw, 92px);
  background: var(--ink);
  color: var(--chalk);
}

.page-about .ab-eco::before {
  content: "";
  position: absolute;
  left: 0;
  right: 0;
  top: 0;
  height: clamp(26px, 6vw, 64px);
  background: var(--paper);
  clip-path: polygon(0 0, 100% 0, 100% 100%);
  pointer-events: none;
}

.page-about .ab-eco .ab-lead {
  color: var(--paper-dim);
}

.page-about .ab-eco__layout {
  display: grid;
  gap: clamp(28px, 4.5vw, 52px);
}

.page-about .ab-eco__stats {
  list-style: none;
  margin: clamp(22px, 3.4vw, 32px) 0 0;
  padding: 0;
}

.page-about .ab-eco__stats li {
  display: flex;
  align-items: baseline;
  gap: 14px;
  padding: 12px 0;
  border-bottom: 1px solid rgba(53, 240, 208, 0.18);
}

.page-about .ab-eco__snum {
  font-family: var(--font-mono);
  font-size: clamp(26px, 4vw, 36px);
  line-height: 1;
  color: var(--cyan);
  letter-spacing: -0.02em;
  flex: 0 0 auto;
  min-width: 2.6em;
}

.page-about .ab-eco__snum em {
  font-style: normal;
  font-size: 0.55em;
  color: var(--orange);
}

.page-about .ab-eco__slabel {
  font-size: 13px;
  line-height: 1.6;
  color: var(--paper-dim);
}

.page-about .ab-eco__sub {
  margin: 0 0 16px;
  font-size: 18px;
  font-weight: 600;
  line-height: 1.4;
  color: var(--chalk);
}

.page-about .ab-eco .filter-bar {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
  margin-bottom: 18px;
}

.page-about .filter-chip {
  font-family: inherit;
  font-size: 13px;
  line-height: 1;
  padding: 9px 16px;
  border-radius: 999px;
  border: 1px solid rgba(53, 240, 208, 0.34);
  background: transparent;
  color: var(--paper-dim);
  cursor: pointer;
  transition: background 0.18s var(--ease), color 0.18s var(--ease), border-color 0.18s var(--ease);
}

.page-about .filter-chip:hover {
  border-color: var(--cyan);
  color: var(--chalk);
}

.page-about .filter-chip[aria-pressed="true"] {
  background: var(--cyan);
  border-color: var(--cyan);
  color: var(--ink);
  font-weight: 600;
}

.page-about .ab-eco__grid {
  display: grid;
  gap: 10px;
  grid-template-columns: repeat(auto-fill, minmax(150px, 1fr));
}

.page-about .ab-eco__item {
  padding: 14px 16px 16px;
  background: rgba(12, 42, 33, 0.78);
  border: 1px solid rgba(53, 240, 208, 0.2);
  border-radius: var(--radius-md);
}

.page-about [data-filter-item][hidden] {
  display: none;
}

.page-about .ab-eco__type {
  display: inline-block;
  font-family: var(--font-mono);
  font-size: 10px;
  letter-spacing: 0.16em;
  color: var(--orange);
  text-transform: uppercase;
}

.page-about .ab-eco__item h4 {
  margin: 6px 0 6px;
  font-size: 15px;
  font-weight: 600;
  line-height: 1.4;
  color: var(--chalk);
}

.page-about .ab-eco__count {
  margin: 0 0 6px;
  font-family: var(--font-mono);
  font-size: 15px;
  color: var(--cyan);
  letter-spacing: 0.02em;
}

.page-about .ab-eco__note {
  margin: 0;
  font-size: 12.5px;
  line-height: 1.65;
  color: var(--paper-dim);
}

.page-about [data-filter-empty] {
  display: none;
  margin: 14px 0 0;
  font-size: 13px;
  color: var(--paper-dim);
}

.page-about [data-filter-empty][data-open="true"] {
  display: block;
}

/* ---------- 工作方式（暖纸） ---------- */
.page-about .ab-practice {
  position: relative;
  padding: clamp(56px, 8vw, 104px) 0 clamp(48px, 7vw, 92px);
  background: var(--paper);
  color: var(--black);
}

.page-about .ab-practice::before {
  content: "";
  position: absolute;
  left: 0;
  right: 0;
  top: 0;
  height: clamp(26px, 6vw, 64px);
  background: var(--ink);
  clip-path: polygon(0 0, 100% 0, 0 100%);
  pointer-events: none;
}

.page-about .ab-practice .eyebrow {
  color: var(--orange-ink);
}

.page-about .ab-practice .ab-lead {
  color: rgba(16, 25, 21, 0.78);
}

.page-about .ab-practice__layout {
  display: grid;
  gap: clamp(24px, 4vw, 48px);
}

.page-about .ab-practice__list {
  display: grid;
  gap: 0;
}

.page-about .ab-practice__item {
  display: grid;
  grid-template-columns: auto minmax(0, 1fr);
  gap: 16px;
  padding: 20px 0;
  border-top: 1px solid var(--paper-dim);
}

.page-about .ab-practice__idx {
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.18em;
  color: var(--orange-ink);
  padding-top: 4px;
}

.page-about .ab-practice__item h3 {
  margin: 0 0 8px;
  font-size: 17px;
  font-weight: 600;
  color: var(--black);
}

.page-about .ab-practice__item p {
  margin: 0;
  font-size: 14.5px;
  line-height: 1.78;
  color: rgba(16, 25, 21, 0.78);
}

/* ---------- 结尾行动区 ---------- */
.page-about .ab-cta {
  position: relative;
  overflow: hidden;
  padding: clamp(56px, 8vw, 104px) 0 clamp(56px, 8vw, 96px);
  background:
    radial-gradient(110% 80% at 90% 0%, rgba(255, 122, 61, 0.16), transparent 62%),
    var(--deep);
  color: var(--chalk);
}

.page-about .ab-cta::before {
  content: "";
  position: absolute;
  left: 0;
  right: 0;
  top: 0;
  height: clamp(26px, 6vw, 64px);
  background: var(--paper);
  clip-path: polygon(0 0, 100% 0, 100% 100%);
  pointer-events: none;
}

.page-about .ab-cta__inner {
  position: relative;
  max-width: 760px;
}

.page-about .ab-cta .eyebrow {
  margin-top: 0;
  color: var(--orange);
}

.page-about .ab-cta__title {
  margin: 14px 0 0;
  font-size: clamp(26px, 4.6vw, 48px);
  font-weight: 300;
  line-height: 1.14;
  letter-spacing: -0.02em;
  transform: skewX(-2deg);
  transform-origin: left bottom;
}

.page-about .ab-cta__text {
  margin: 18px 0 0;
  max-width: 54ch;
  font-size: 15px;
  line-height: 1.8;
  color: var(--paper-dim);
}

.page-about .ab-cta__actions {
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
  margin-top: clamp(22px, 3.5vw, 32px);
}

/* ---------- 响应式 ---------- */
@media (min-width: 600px) {
  .page-about .ab-stats {
    grid-template-columns: repeat(3, minmax(0, 1fr));
    gap: 12px;
  }

  .page-about .ab-team__grid {
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }

  .page-about .ab-eco__grid {
    grid-template-columns: repeat(auto-fill, minmax(180px, 1fr));
  }
}

@media (min-width: 900px) {
  .page-about .ab-cover__grid {
    grid-template-columns: minmax(0, 7fr) minmax(0, 5fr);
    align-items: end;
  }

  .page-about .ab-cover__figure {
    margin-bottom: 6px;
  }

  .page-about .ab-timeline__item {
    padding-left: 200px;
    padding-bottom: 46px;
  }

  .page-about .ab-timeline::before {
    left: 149px;
    width: 2px;
  }

  .page-about .ab-timeline__item::before {
    left: 141px;
    top: 8px;
    width: 18px;
    height: 18px;
  }

  .page-about .ab-timeline__year {
    position: absolute;
    left: 0;
    top: 0;
    width: 126px;
    margin: 0;
    font-size: 36px;
    letter-spacing: 0.02em;
    line-height: 1;
  }

  .page-about .ab-timeline__extra {
    max-height: 0;
    opacity: 0;
    transition: max-height 0.28s var(--ease), opacity 0.22s var(--ease);
  }

  .page-about .ab-timeline__item:hover .ab-timeline__extra,
  .page-about .ab-timeline__item:focus .ab-timeline__extra,
  .page-about .ab-timeline__item:focus-within .ab-timeline__extra {
    max-height: 180px;
    opacity: 1;
  }

  .page-about .ab-team__grid {
    grid-template-columns: repeat(3, minmax(0, 1fr));
  }

  .page-about .ab-eco__layout {
    grid-template-columns: minmax(0, 5fr) minmax(0, 7fr);
    align-items: start;
  }

  .page-about .ab-practice__layout {
    grid-template-columns: minmax(0, 5fr) minmax(0, 7fr);
    align-items: start;
  }
}

@media (min-width: 1200px) {
  .page-about .ab-cover__grid {
    grid-template-columns: minmax(0, 7.2fr) minmax(0, 4.8fr);
  }
}

@media (prefers-reduced-motion: reduce) {
  .page-about .ab-stat,
  .page-about .ab-timeline__item::before,
  .page-about .ab-timeline__extra,
  .page-about .filter-chip {
    transition: none;
  }

  .page-about .ab-stat:hover {
    transform: none;
  }
}