.page-about {
  --ab-aside: 104px;
  background: var(--yk-sand);
  color: var(--yk-ink);
}

/* ---------- 首屏 ---------- */
.page-about .ab-crumb {
  margin-bottom: 12px;
}

.page-about .ab-hero {
  position: relative;
  overflow: hidden;
  padding: clamp(18px, 3vw, 32px) 0 clamp(40px, 6vw, 76px);
  border-bottom: 3px solid var(--yk-ink);
}

.page-about .ab-hero::before {
  content: "";
  position: absolute;
  left: -10%;
  top: -34%;
  width: 64%;
  height: 160%;
  background: rgba(15, 107, 107, 0.13);
  border-right: 2px solid rgba(15, 107, 107, 0.35);
  transform: rotate(-9deg);
  pointer-events: none;
}

.page-about .ab-hero__ctx {
  position: relative;
  display: inline-flex;
  align-items: center;
  gap: 8px;
  margin: 0 0 clamp(16px, 3vw, 28px);
  padding: 5px 10px;
  background: var(--yk-paper);
  border: 2px solid var(--yk-ink);
  font-family: var(--yk-font-mono);
  font-size: 12px;
  letter-spacing: 0.04em;
  color: var(--yk-ink);
}

.page-about .ab-hero__ctx::before {
  content: "";
  width: 8px;
  height: 8px;
  background: var(--yk-green);
  flex: none;
}

.page-about .ab-hero__grid {
  position: relative;
  display: grid;
  grid-template-columns: 1fr;
  gap: clamp(28px, 5vw, 52px);
}

.page-about .ab-hero__title {
  margin: 0 0 18px;
  font-family: var(--yk-font-head);
  font-weight: 800;
  font-size: clamp(38px, 7.4vw, 90px);
  line-height: 0.98;
  letter-spacing: -0.02em;
  color: var(--yk-ink);
}

.page-about .ab-hero__title span {
  display: block;
  color: var(--yk-teal);
}

.page-about .ab-hero__lede {
  margin: 0 0 16px;
  max-width: 34em;
  font-size: clamp(16px, 1.6vw, 19px);
  line-height: 1.8;
  color: var(--yk-ink);
}

.page-about .ab-hero__sub {
  margin: 0 0 clamp(20px, 3vw, 28px);
  padding-left: 12px;
  border-left: 4px solid var(--yk-orange);
  font-family: var(--yk-font-mono);
  font-size: 13px;
  letter-spacing: 0.02em;
  color: var(--yk-gray);
}

.page-about .ab-hero__actions {
  flex-wrap: wrap;
}

.page-about .ab-hero__figure {
  position: relative;
  margin: 0;
  isolation: isolate;
}

.page-about .ab-hero__figure::before {
  content: "";
  position: absolute;
  inset: 16px -12px -12px 12px;
  background: var(--yk-teal);
  transform: rotate(-2.4deg);
  z-index: 0;
}

.page-about .ab-hero__figure img {
  position: relative;
  z-index: 1;
  display: block;
  width: 100%;
  max-width: 100%;
  height: auto;
  border: 3px solid var(--yk-ink);
  box-shadow: var(--yk-shadow);
  object-fit: cover;
}

.page-about .ab-hero__cap {
  position: relative;
  z-index: 1;
  display: flex;
  flex-wrap: wrap;
  justify-content: space-between;
  gap: 6px 16px;
  margin-top: 10px;
  font-family: var(--yk-font-mono);
  font-size: 12px;
  letter-spacing: 0.05em;
  color: var(--yk-gray);
}

/* ---------- 通用章节骨架 ---------- */
.page-about .ab-split {
  display: grid;
  grid-template-columns: 1fr;
  gap: clamp(18px, 3vw, 36px);
}

.page-about .ab-num {
  display: inline-block;
  padding-bottom: 8px;
  border-bottom: 3px solid var(--yk-orange);
  font-family: var(--yk-font-head);
  font-weight: 700;
  font-size: clamp(32px, 5vw, 54px);
  line-height: 1;
  letter-spacing: -0.03em;
  color: var(--yk-teal);
}

.page-about .ab-aside-label {
  margin: 10px 0 0;
  font-family: var(--yk-font-mono);
  font-size: 12px;
  letter-spacing: 0.16em;
  color: var(--yk-gray);
}

.page-about .ab-split__body .yk-h2 {
  margin: 0 0 16px;
}

.page-about .ab-split__body .yk-text {
  margin: 0 0 14px;
  line-height: 1.85;
}

/* ---------- 坐标起点 ---------- */
.page-about .ab-origin {
  padding: clamp(44px, 7vw, 88px) 0;
  background: var(--yk-paper);
  border-top: 3px solid var(--yk-ink);
}

.page-about .ab-keyline {
  display: flex;
  align-items: flex-start;
  gap: 10px;
  margin: clamp(20px, 3vw, 28px) 0 0;
  padding: 14px 16px;
  background: var(--yk-mint);
  border-left: 6px solid var(--yk-teal);
  font-size: 15px;
  line-height: 1.7;
  color: var(--yk-deep);
}

.page-about .ab-pin {
  flex: none;
  display: inline-block;
  width: 12px;
  height: 12px;
  margin-top: 5px;
  border: 2px solid var(--yk-orange);
  border-radius: 50%;
  transition: background 0.16s var(--yk-ease);
}

.page-about .ab-keyline:hover .ab-pin {
  background: var(--yk-orange);
}

/* ---------- 服务主张 ---------- */
.page-about .ab-claim {
  padding: clamp(44px, 7vw, 88px) 0;
  background: var(--yk-deep);
  color: var(--yk-paper);
  border-top: 3px solid var(--yk-ink);
  border-bottom: 3px solid var(--yk-ink);
}

.page-about .ab-claim__inner {
  display: grid;
  grid-template-columns: 1fr;
  gap: clamp(18px, 3vw, 36px);
}

.page-about .ab-claim .ab-num {
  color: var(--yk-sand);
  border-bottom-color: var(--yk-orange);
}

.page-about .ab-claim .ab-aside-label {
  color: var(--yk-mint);
}

.page-about .ab-claim__title {
  margin: 0 0 16px;
  color: var(--yk-paper);
}

.page-about .ab-claim__lede {
  margin: 0;
  max-width: 40em;
  font-size: 16px;
  line-height: 1.85;
  color: var(--yk-mint);
}

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

.page-about .ab-claim__list li {
  padding: 22px 0;
  border-top: 1px solid rgba(216, 232, 228, 0.28);
}

.page-about .ab-claim__list li:last-child {
  border-bottom: 1px solid rgba(216, 232, 228, 0.28);
}

.page-about .ab-claim__tag {
  display: inline-block;
  margin-bottom: 10px;
  padding: 3px 10px;
  border: 2px solid var(--yk-orange);
  font-family: var(--yk-font-mono);
  font-size: 12px;
  letter-spacing: 0.12em;
  color: var(--yk-orange);
}

.page-about .ab-claim__list .yk-h3 {
  margin: 0 0 8px;
  color: var(--yk-paper);
}

.page-about .ab-claim__list p {
  margin: 0;
  max-width: 34em;
  font-size: 16px;
  line-height: 1.85;
  color: var(--yk-mint);
}

/* ---------- 发展路径 ---------- */
.page-about .ab-path {
  padding: clamp(44px, 7vw, 88px) 0;
  background: var(--yk-sand);
}

.page-about .ab-track {
  position: relative;
  margin: clamp(26px, 4vw, 40px) 0 0;
  padding: 0 0 0 28px;
  border-left: 3px solid var(--yk-line);
  list-style: none;
  display: grid;
  gap: clamp(18px, 2.6vw, 28px);
}

.page-about .ab-track__item {
  position: relative;
  padding: 18px 20px;
  background: var(--yk-paper);
  border: 2px solid var(--yk-ink);
  box-shadow: 6px 6px 0 rgba(19, 42, 58, 0.14);
  transition: transform 0.16s var(--yk-ease), box-shadow 0.16s var(--yk-ease);
}

.page-about .ab-track__item:hover,
.page-about .ab-track__item:focus-within {
  transform: translateX(3px);
  box-shadow: 6px 6px 0 var(--yk-teal);
}

.page-about .ab-track__dot {
  position: absolute;
  left: -8px;
  top: 24px;
  width: 14px;
  height: 14px;
  border: 3px solid var(--yk-orange);
  border-radius: 50%;
  background: var(--yk-sand);
  transition: background 0.16s var(--yk-ease);
}

.page-about .ab-track__item:hover .ab-track__dot,
.page-about .ab-track__item:focus-within .ab-track__dot {
  background: var(--yk-orange);
}

.page-about .ab-track__idx {
  margin: 0 0 6px;
  font-family: var(--yk-font-mono);
  font-size: 12px;
  letter-spacing: 0.14em;
  color: var(--yk-orange);
}

.page-about .ab-track__item .yk-h3 {
  margin: 0 0 8px;
  color: var(--yk-ink);
}

.page-about .ab-track__item .yk-text {
  margin: 0 0 12px;
  font-size: 15px;
  line-height: 1.8;
}

.page-about .ab-track__key {
  display: inline-block;
  margin: 0;
  padding: 4px 9px;
  background: var(--yk-mint);
  font-family: var(--yk-font-mono);
  font-size: 12px;
  letter-spacing: 0.04em;
  color: var(--yk-deep);
}

/* ---------- 团队分工 ---------- */
.page-about .ab-team {
  padding: clamp(44px, 7vw, 88px) 0;
  background: var(--yk-mint);
  border-top: 3px solid var(--yk-ink);
  border-bottom: 3px solid var(--yk-ink);
}

.page-about .ab-team__grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: clamp(26px, 4vw, 48px);
}

.page-about .ab-team__copy .yk-h2 {
  margin: 12px 0 16px;
}

.page-about .ab-team__copy .yk-text {
  margin: 0 0 20px;
  line-height: 1.85;
}

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

.page-about .ab-team__list li {
  padding: 14px 0;
  border-top: 2px solid rgba(19, 42, 58, 0.16);
}

.page-about .ab-team__list li:last-child {
  border-bottom: 2px solid rgba(19, 42, 58, 0.16);
}

.page-about .ab-team__name {
  margin: 0 0 4px;
  font-family: var(--yk-font-mono);
  font-size: 13px;
  letter-spacing: 0.08em;
  color: var(--yk-deep);
}

.page-about .ab-team__list p {
  margin: 0;
  font-size: 15px;
  line-height: 1.75;
  color: var(--yk-ink);
}

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

.page-about .ab-team__figure img {
  display: block;
  width: 100%;
  max-width: 100%;
  height: auto;
  border: 3px solid var(--yk-ink);
  box-shadow: var(--yk-shadow);
  object-fit: cover;
}

.page-about .ab-team__cap {
  margin-top: 10px;
  font-family: var(--yk-font-mono);
  font-size: 12px;
  letter-spacing: 0.05em;
  color: var(--yk-gray);
}

.page-about .ab-partner {
  margin: clamp(26px, 4vw, 40px) 0 0;
  padding: 18px 20px;
  background: var(--yk-deep);
  border-left: 8px solid var(--yk-orange);
  font-size: 15px;
  line-height: 1.85;
  color: var(--yk-paper);
}

/* ---------- 选择理由 ---------- */
.page-about .ab-why {
  padding: clamp(44px, 7vw, 88px) 0;
  background: var(--yk-sand);
}

.page-about .ab-why__grid {
  margin-top: clamp(24px, 4vw, 40px);
  display: grid;
  grid-template-columns: 1fr;
  gap: 14px;
}

.page-about .ab-why__item {
  padding: 16px 18px 18px;
  background: var(--yk-paper);
  border: 2px solid var(--yk-ink);
  box-shadow: 5px 5px 0 rgba(19, 42, 58, 0.14);
  transition: box-shadow 0.16s var(--yk-ease), transform 0.16s var(--yk-ease);
}

.page-about .ab-why__item:hover {
  transform: translateY(-2px);
  box-shadow: 5px 5px 0 var(--yk-teal);
}

.page-about .ab-why__item summary {
  display: block;
  list-style: none;
  cursor: pointer;
}

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

.page-about .ab-why__item summary:focus-visible {
  outline: 2px solid var(--yk-orange);
  outline-offset: 4px;
}

.page-about .ab-why__value {
  display: block;
  font-family: var(--yk-font-head);
  font-weight: 700;
  font-size: clamp(28px, 4vw, 42px);
  line-height: 1.05;
  letter-spacing: -0.02em;
  color: var(--yk-teal);
}

.page-about .ab-why__label {
  display: block;
  margin-top: 6px;
  font-family: var(--yk-font-mono);
  font-size: 12px;
  letter-spacing: 0.08em;
  color: var(--yk-gray);
}

.page-about .ab-why__item p {
  margin: 12px 0 0;
  padding-top: 12px;
  border-top: 1px dashed var(--yk-line);
  font-size: 15px;
  line-height: 1.75;
  color: var(--yk-ink);
}

/* ---------- 品牌气质 ---------- */
.page-about .ab-mood {
  padding: clamp(44px, 7vw, 88px) 0;
  background: var(--yk-paper);
  border-top: 3px solid var(--yk-ink);
}

.page-about .ab-mood__figure {
  margin: clamp(24px, 4vw, 36px) 0 0;
  border: 3px solid var(--yk-ink);
  box-shadow: var(--yk-shadow);
}

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

.page-about .ab-mood__cap {
  padding: 10px 14px;
  border-top: 2px solid var(--yk-ink);
  background: var(--yk-mint);
  font-family: var(--yk-font-mono);
  font-size: 12px;
  letter-spacing: 0.05em;
  color: var(--yk-deep);
}

.page-about .ab-mood__specs {
  margin-top: clamp(26px, 4vw, 38px);
  display: grid;
  grid-template-columns: 1fr;
  gap: 20px;
}

.page-about .ab-mood__spec {
  padding-top: 14px;
  border-top: 3px solid var(--yk-teal);
}

.page-about .ab-mood__spec .yk-h3 {
  margin: 0 0 8px;
  color: var(--yk-ink);
}

.page-about .ab-mood__spec p {
  margin: 0;
  font-size: 15px;
  line-height: 1.8;
  color: var(--yk-gray);
}

.page-about .ab-swatch {
  display: block;
  width: 46px;
  height: 46px;
  margin-bottom: 12px;
  border: 2px solid var(--yk-ink);
}

.page-about .ab-swatch--teal {
  background: var(--yk-teal);
}

.page-about .ab-swatch--orange {
  background: var(--yk-orange);
}

.page-about .ab-swatch--ink {
  background: var(--yk-ink);
  box-shadow: inset 0 0 0 8px var(--yk-sand);
}

/* ---------- 收尾行动区 ---------- */
.page-about .ab-cta {
  padding: clamp(36px, 6vw, 64px) 0;
  background: var(--yk-teal);
  color: var(--yk-paper);
  border-top: 3px solid var(--yk-ink);
}

.page-about .ab-cta__inner {
  display: grid;
  grid-template-columns: 1fr;
  gap: clamp(20px, 3vw, 32px);
}

.page-about .ab-cta__title {
  margin: 0 0 10px;
  color: var(--yk-paper);
}

.page-about .ab-cta__copy p {
  margin: 0;
  max-width: 40em;
  font-size: 15px;
  line-height: 1.8;
  color: var(--yk-mint);
}

.page-about .ab-cta__actions {
  flex-wrap: wrap;
}

.page-about .ab-cta .yk-btn--ghost {
  border-color: var(--yk-paper);
  color: var(--yk-paper);
}

/* ---------- 桌面栅格 ---------- */
@media (min-width: 860px) {
  .page-about .ab-split {
    grid-template-columns: var(--ab-aside) minmax(0, 1fr);
    gap: clamp(28px, 5vw, 64px);
  }

  .page-about .ab-claim__inner {
    grid-template-columns: var(--ab-aside) minmax(0, 1fr);
    gap: clamp(28px, 5vw, 64px);
  }

  .page-about .ab-claim__list li {
    display: grid;
    grid-template-columns: 96px minmax(0, 1fr);
    align-items: start;
    column-gap: 20px;
  }

  .page-about .ab-claim__tag {
    margin-bottom: 0;
    grid-row: span 2;
    justify-self: start;
  }

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

  .page-about .ab-cta__actions {
    justify-content: flex-end;
  }
}

@media (min-width: 900px) {
  .page-about .ab-hero__grid {
    grid-template-columns: minmax(0, 1.05fr) minmax(0, 0.95fr);
    align-items: start;
  }

  .page-about .ab-team__grid {
    grid-template-columns: minmax(0, 1.1fr) minmax(0, 0.9fr);
    align-items: start;
  }

  .page-about .ab-mood__specs {
    grid-template-columns: repeat(3, minmax(0, 1fr));
    gap: 28px;
  }
}

@media (min-width: 1000px) {
  .page-about .ab-why__grid {
    grid-template-columns: repeat(4, minmax(0, 1fr));
  }
}

@media (min-width: 640px) and (max-width: 999px) {
  .page-about .ab-why__grid {
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }
}

@media (prefers-reduced-motion: reduce) {
  .page-about .ab-track__item,
  .page-about .ab-track__dot,
  .page-about .ab-why__item,
  .page-about .ab-pin {
    transition: none;
  }

  .page-about .ab-track__item:hover,
  .page-about .ab-track__item:focus-within,
  .page-about .ab-why__item:hover {
    transform: none;
  }
}