.page-about {
  --ab-gap: clamp(20px, 4vw, 32px);
  --ab-radius: 2px;
  background: var(--yh-paper);
  color: var(--yh-ink);
  font-family: var(--yh-font-body);
  line-height: 1.75;
  overflow-x: clip;
}

/* ---------- 首屏 ---------- */
.page-about .ab-hero {
  position: relative;
  background: var(--yh-ink);
  color: var(--yh-paper);
  padding: clamp(36px, 7vw, 72px) 0 clamp(36px, 6vw, 68px);
  overflow: hidden;
}
.page-about .ab-hero__texture {
  position: absolute;
  inset: 0;
  pointer-events: none;
  background-image:
    repeating-linear-gradient(115deg, rgba(224, 165, 38, 0.09) 0 2px, transparent 2px 28px),
    radial-gradient(120% 95% at 88% 6%, rgba(224, 165, 38, 0.22), transparent 58%),
    linear-gradient(162deg, #0B0B0C 0%, #16181B 60%, #0F3B32 100%);
}
.page-about .ab-hero__inner {
  position: relative;
  z-index: 1;
}
.page-about .ab-hero .yh-crumbs {
  color: rgba(246, 243, 237, 0.62);
}
.page-about .ab-hero .yh-crumbs__item a {
  color: rgba(246, 243, 237, 0.82);
  text-decoration: none;
}
.page-about .ab-hero .yh-crumbs__item a:hover {
  color: var(--yh-amber-soft);
}
.page-about .ab-hero__eyebrow {
  margin: clamp(20px, 3vw, 30px) 0 0;
  font-family: var(--yh-font-mono);
  font-size: clamp(12px, 1.6vw, 14px);
  letter-spacing: 0.08em;
  color: var(--yh-amber);
}
.page-about .ab-hero__title {
  margin: 14px 0 0;
  font-family: var(--yh-font-display);
  font-weight: 900;
  font-size: clamp(32px, 7.6vw, 68px);
  line-height: 1.08;
  letter-spacing: -0.01em;
}
.page-about .ab-hero__title span {
  color: var(--yh-amber);
}
.page-about .ab-hero__lead {
  margin: 20px 0 0;
  max-width: 46em;
  font-size: clamp(15px, 2.2vw, 17px);
  line-height: 1.8;
  color: rgba(246, 243, 237, 0.84);
}

.page-about .ab-facts {
  list-style: none;
  margin: clamp(28px, 5vw, 44px) 0 0;
  padding: 1px;
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 1px;
  background: rgba(222, 215, 201, 0.22);
  border: 1px solid rgba(222, 215, 201, 0.16);
}
.page-about .ab-facts > li {
  background: rgba(11, 11, 12, 0.72);
  padding: 16px 16px 14px;
  display: flex;
  flex-direction: column;
  gap: 2px;
}
.page-about .ab-facts__num {
  font-family: var(--yh-font-mono);
  font-weight: 700;
  font-size: clamp(22px, 4.6vw, 34px);
  line-height: 1.1;
  color: var(--yh-amber);
  letter-spacing: -0.02em;
}
.page-about .ab-facts__unit {
  font-size: 0.52em;
  margin-left: 3px;
  color: var(--yh-amber-soft);
}
.page-about .ab-facts__label {
  font-size: 13px;
  color: rgba(246, 243, 237, 0.66);
}

/* ---------- 主壳 ---------- */
.page-about .ab-shell {
  padding: clamp(24px, 5vw, 56px) 0 clamp(48px, 8vw, 96px);
}
.page-about .ab-shell__inner {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: var(--ab-gap);
  align-items: start;
}

/* ---------- 章节导航 ---------- */
.page-about .ab-toc {
  position: sticky;
  top: 0;
  z-index: 6;
  background: var(--yh-paper);
  padding: 8px 0 10px;
  border-bottom: 1px solid var(--yh-line);
}
.page-about .ab-toc__title {
  margin: 0 0 8px;
  font-family: var(--yh-font-mono);
  font-size: 12px;
  letter-spacing: 0.1em;
  color: #6B6459;
}
.page-about .ab-toc__list {
  list-style: none;
  margin: 0;
  padding: 0 0 4px;
  display: flex;
  gap: 6px;
  overflow-x: auto;
  scrollbar-width: thin;
}
.page-about .ab-toc__link {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  white-space: nowrap;
  padding: 7px 12px;
  font-size: 13px;
  color: var(--yh-ink);
  text-decoration: none;
  background: #FFFDF8;
  border: 1px solid var(--yh-line);
  transition: background 0.18s var(--yh-ease), border-color 0.18s var(--yh-ease);
}
.page-about .ab-toc__link .yh-mono {
  font-family: var(--yh-font-mono);
  font-size: 12px;
  font-weight: 700;
  color: var(--yh-amber);
}
.page-about .ab-toc__link:hover {
  border-color: var(--yh-amber);
}
.page-about .ab-toc__link.is-current {
  background: var(--yh-ink);
  border-color: var(--yh-ink);
  color: var(--yh-paper);
  font-weight: 700;
}
.page-about .ab-toc__link.is-current .yh-mono {
  color: var(--yh-amber-soft);
}

/* ---------- 章节头 ---------- */
.page-about .ab-sec {
  padding-bottom: clamp(36px, 6vw, 64px);
}
.page-about .ab-sec:last-of-type {
  padding-bottom: 0;
}
.page-about .ab-head {
  display: grid;
  grid-template-columns: auto minmax(0, 1fr);
  gap: 14px 18px;
  align-items: start;
  padding-top: 18px;
  margin-bottom: clamp(20px, 3.5vw, 30px);
  border-top: 1px solid var(--yh-line);
}
.page-about .ab-head__idx {
  font-family: var(--yh-font-mono);
  font-weight: 700;
  font-size: clamp(26px, 5.6vw, 44px);
  line-height: 1;
  letter-spacing: -0.03em;
  color: var(--yh-amber);
}
.page-about .ab-head__title {
  margin: 0;
  font-family: var(--yh-font-display);
  font-weight: 800;
  font-size: clamp(21px, 4vw, 32px);
  line-height: 1.28;
  letter-spacing: -0.01em;
}
.page-about .ab-head__lead {
  margin: 10px 0 0;
  font-size: clamp(14px, 2.1vw, 16px);
  line-height: 1.8;
  color: #4A4640;
}

/* ---------- 时间轴 ---------- */
.page-about .ab-timeline {
  position: relative;
  display: grid;
  gap: 12px;
  padding: clamp(20px, 4vw, 32px) clamp(14px, 3vw, 26px) clamp(20px, 4vw, 32px) clamp(28px, 5vw, 46px);
  background: var(--yh-ink);
  overflow: hidden;
  clip-path: polygon(0 0, calc(100% - 30px) 0, 100% 30px, 100% 100%, 0 100%);
}
.page-about .ab-timeline__bg {
  position: absolute;
  inset: 0;
  z-index: 0;
  pointer-events: none;
}
.page-about .ab-timeline__bg img {
  width: 100%;
  height: 100%;
  object-fit: cover;
  opacity: 0.16;
}
.page-about .ab-timeline::before {
  content: "";
  position: absolute;
  left: clamp(12px, 2.4vw, 22px);
  top: 0;
  bottom: 0;
  width: 2px;
  z-index: 0;
  background: linear-gradient(180deg, transparent, rgba(224, 165, 38, 0.55) 10%, rgba(224, 165, 38, 0.55) 90%, transparent);
}
.page-about .ab-node {
  position: relative;
  z-index: 1;
  background: rgba(22, 24, 27, 0.9);
  border: 1px solid rgba(222, 215, 201, 0.18);
  border-left: 3px solid var(--yh-amber);
}
.page-about .ab-node::before {
  content: "";
  position: absolute;
  left: 0;
  top: 50%;
  width: 9px;
  height: 9px;
  margin-left: -5px;
  transform: translate(-100%, -50%);
  border-radius: 50%;
  background: var(--yh-amber);
}
.page-about .ab-node__head {
  list-style: none;
  cursor: pointer;
  display: grid;
  grid-template-columns: auto minmax(0, 1fr) 20px;
  gap: 12px;
  align-items: center;
  padding: 14px 16px;
  color: var(--yh-paper);
}
.page-about .ab-node__head::-webkit-details-marker {
  display: none;
}
.page-about .ab-node__head:focus-visible {
  outline: 2px solid var(--yh-amber-soft);
  outline-offset: -2px;
}
.page-about .ab-node__year {
  font-family: var(--yh-font-mono);
  font-weight: 700;
  font-size: clamp(19px, 3.4vw, 26px);
  letter-spacing: -0.02em;
  color: var(--yh-amber);
}
.page-about .ab-node__title {
  font-family: var(--yh-font-display);
  font-weight: 700;
  font-size: clamp(14px, 2.3vw, 18px);
  line-height: 1.4;
}
.page-about .ab-node__sign {
  position: relative;
  width: 18px;
  height: 18px;
  border: 1px solid rgba(224, 165, 38, 0.6);
}
.page-about .ab-node__sign::before,
.page-about .ab-node__sign::after {
  content: "";
  position: absolute;
  left: 50%;
  top: 50%;
  background: var(--yh-amber-soft);
  transform: translate(-50%, -50%);
}
.page-about .ab-node__sign::before {
  width: 9px;
  height: 2px;
}
.page-about .ab-node__sign::after {
  width: 2px;
  height: 9px;
  transition: transform 0.2s var(--yh-ease), opacity 0.2s var(--yh-ease);
}
.page-about .ab-node[open] .ab-node__sign::after {
  transform: translate(-50%, -50%) scaleY(0);
  opacity: 0;
}
.page-about .ab-node__body {
  padding: 0 16px 16px;
  border-top: 1px dashed rgba(222, 215, 201, 0.2);
  margin-top: 2px;
}
.page-about .ab-node__body p {
  margin: 12px 0 0;
  font-size: 15px;
  line-height: 1.8;
  color: rgba(246, 243, 237, 0.82);
}

/* ---------- 产品谱系 ---------- */
.page-about .ab-map-wrap {
  margin: 0 0 8px;
  padding: clamp(12px, 3vw, 22px);
  background: #FFFDF8;
  border: 1px solid var(--yh-line);
  overflow-x: auto;
}
.page-about .ab-map {
  display: block;
  width: 100%;
  min-width: 520px;
  height: auto;
}
.page-about .ab-lines {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 12px;
  margin: clamp(16px, 3vw, 24px) 0 0;
}
.page-about .ab-line {
  padding: 16px 18px;
  background: #16181B;
  color: var(--yh-paper);
  border-left: 3px solid var(--yh-green-2);
}
.page-about .ab-line--pocket {
  border-left-color: var(--yh-green-2);
}
.page-about .ab-line--standard {
  border-left-color: var(--yh-amber);
}
.page-about .ab-line--flagship {
  border-left-color: var(--yh-blue-2);
}
.page-about .ab-line__name {
  margin: 0;
  font-family: var(--yh-font-display);
  font-weight: 700;
  font-size: 17px;
  color: var(--yh-amber-soft);
}
.page-about .ab-line__text {
  margin: 8px 0 0;
  font-size: 14.5px;
  line-height: 1.8;
  color: rgba(246, 243, 237, 0.8);
}
.page-about .ab-scope-media {
  margin: clamp(18px, 3vw, 26px) 0 0;
}

/* ---------- 双版本 ---------- */
.page-about .ab-duo {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 14px;
}
.page-about .ab-duo__card {
  position: relative;
  padding: clamp(18px, 3vw, 26px);
  background: #FFFDF8;
  border: 1px solid var(--yh-line);
  border-top: 4px solid var(--yh-blue);
}
.page-about .ab-duo__card--amber {
  border-top-color: var(--yh-amber);
  background: #FCF6E8;
}
.page-about .ab-duo__tag {
  display: inline-block;
  font-family: var(--yh-font-mono);
  font-size: 12px;
  letter-spacing: 0.08em;
  padding: 3px 9px;
  background: var(--yh-blue);
  color: var(--yh-paper);
}
.page-about .ab-duo__card--amber .ab-duo__tag {
  background: var(--yh-amber);
  color: var(--yh-ink);
}
.page-about .ab-duo__title {
  margin: 14px 0 0;
  font-family: var(--yh-font-display);
  font-weight: 800;
  font-size: clamp(18px, 3vw, 23px);
  line-height: 1.35;
}
.page-about .ab-duo__text {
  margin: 10px 0 0;
  font-size: 15px;
  line-height: 1.8;
  color: #3E3A34;
}
.page-about .ab-note {
  margin: clamp(16px, 3vw, 22px) 0 0;
  padding-left: 14px;
  border-left: 3px solid var(--yh-amber);
  font-size: 14.5px;
  line-height: 1.85;
  color: #4A4640;
}

/* ---------- 团队 ---------- */
.page-about .ab-team {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: clamp(16px, 3vw, 26px);
}
.page-about .ab-roles {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 10px;
}
.page-about .ab-role {
  padding: 14px 16px;
  background: #FFFDF8;
  border: 1px solid var(--yh-line);
  border-left: 3px solid var(--yh-line);
}
.page-about .ab-role--key {
  border-left-color: var(--yh-amber);
  background: #FCF6E8;
}
.page-about .ab-role__name {
  margin: 0;
  font-family: var(--yh-font-display);
  font-weight: 700;
  font-size: 16px;
  display: flex;
  align-items: baseline;
  gap: 10px;
  flex-wrap: wrap;
}
.page-about .ab-role__num {
  font-family: var(--yh-font-mono);
  font-size: 15px;
  font-weight: 700;
  color: var(--yh-green);
}
.page-about .ab-role__text {
  margin: 8px 0 0;
  font-size: 14.5px;
  line-height: 1.8;
  color: #4A4640;
}
.page-about .ab-team__media {
  margin: 0;
}

/* ---------- 资质 ---------- */
.page-about .ab-stats {
  list-style: none;
  margin: 0;
  padding: 0;
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 1px;
  background: var(--yh-line);
  border: 1px solid var(--yh-line);
}
.page-about .ab-stat {
  background: #FFFDF8;
  padding: 16px 14px;
  display: flex;
  flex-direction: column;
  gap: 4px;
}
.page-about .ab-stat:nth-child(3n) {
  background: #F4EFE4;
}
.page-about .ab-stat__num {
  font-family: var(--yh-font-mono);
  font-weight: 700;
  font-size: clamp(24px, 5vw, 36px);
  line-height: 1.05;
  letter-spacing: -0.02em;
  color: var(--yh-ink);
}
.page-about .ab-stat__label {
  font-size: 13px;
  line-height: 1.6;
  color: #5A544B;
}

/* ---------- 覆盖 ---------- */
.page-about .ab-cover {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 12px;
}
.page-about .ab-cover__item {
  display: grid;
  grid-template-columns: auto minmax(0, 1fr);
  gap: 10px 16px;
  align-items: start;
  padding: 16px 18px;
  background: var(--yh-green);
  color: var(--yh-paper);
}
.page-about .ab-cover__num {
  font-family: var(--yh-font-mono);
  font-weight: 700;
  font-size: clamp(22px, 4.4vw, 30px);
  line-height: 1.1;
  color: var(--yh-amber-soft);
  white-space: nowrap;
}
.page-about .ab-cover__text {
  font-size: 14.5px;
  line-height: 1.8;
  color: rgba(246, 243, 237, 0.86);
}

/* ---------- 收束 ---------- */
.page-about .ab-cta {
  margin-top: clamp(8px, 2vw, 18px);
  padding: clamp(24px, 5vw, 40px) clamp(18px, 4vw, 36px);
  background: var(--yh-ink);
  color: var(--yh-paper);
  border-left: 4px solid var(--yh-amber);
}
.page-about .ab-cta__title {
  margin: 0;
  font-family: var(--yh-font-display);
  font-weight: 800;
  font-size: clamp(20px, 3.7vw, 30px);
  line-height: 1.32;
}
.page-about .ab-cta__text {
  margin: 12px 0 0;
  max-width: 44em;
  font-size: 15px;
  line-height: 1.85;
  color: rgba(246, 243, 237, 0.82);
}
.page-about .ab-cta__actions {
  margin-top: 20px;
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
}

/* ---------- 响应式 ---------- */
@media (min-width: 560px) {
  .page-about .ab-facts {
    grid-template-columns: repeat(4, minmax(0, 1fr));
  }
  .page-about .ab-lines {
    grid-template-columns: repeat(3, minmax(0, 1fr));
  }
  .page-about .ab-roles {
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }
  .page-about .ab-cover {
    grid-template-columns: repeat(3, minmax(0, 1fr));
  }
}

@media (min-width: 760px) {
  .page-about .ab-duo {
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }
  .page-about .ab-team {
    grid-template-columns: minmax(0, 1.35fr) minmax(0, 1fr);
    align-items: start;
  }
  .page-about .ab-stats {
    grid-template-columns: repeat(3, minmax(0, 1fr));
  }
}

@media (min-width: 960px) {
  .page-about .ab-shell__inner {
    grid-template-columns: 196px minmax(0, 1fr);
    gap: clamp(32px, 4vw, 60px);
  }
  .page-about .ab-toc {
    top: 84px;
    border-bottom: 0;
    border-left: 2px solid var(--yh-line);
    padding: 4px 0 4px 0;
  }
  .page-about .ab-toc__title {
    padding-left: 14px;
  }
  .page-about .ab-toc__list {
    flex-direction: column;
    overflow: visible;
    gap: 2px;
    padding-bottom: 0;
  }
  .page-about .ab-toc__link {
    border: 0;
    border-left: 2px solid transparent;
    margin-left: -2px;
    background: transparent;
    padding: 8px 10px 8px 14px;
    font-size: 14px;
  }
  .page-about .ab-toc__link.is-current {
    background: transparent;
    border-left-color: var(--yh-amber);
    color: var(--yh-ink);
  }
  .page-about .ab-toc__link.is-current .yh-mono {
    color: var(--yh-amber);
  }
  .page-about .ab-node__head {
    padding: 16px 22px;
  }
  .page-about .ab-node__body {
    padding: 0 22px 18px;
  }
  .page-about .ab-node__body p {
    max-width: 62em;
  }
}

@media (prefers-reduced-motion: reduce) {
  .page-about .ab-node__sign::after,
  .page-about .ab-toc__link {
    transition: none;
  }
}
</main>