.page-about {
  --about-shell: 1180px;
  --about-gap: clamp(20px, 3vw, 36px);
  display: block;
  padding: clamp(20px, 3vw, 40px) clamp(20px, 4vw, 56px) clamp(64px, 8vw, 112px);
  background: var(--yk-green);
  color: var(--yk-paper);
}

.page-about > * + * {
  margin-top: clamp(48px, 7vw, 96px);
}

.page-about .yk-section {
  max-width: var(--about-shell);
  margin-inline: auto;
}

/* ---------- 首屏 ---------- */
.page-about .about-hero {
  margin-top: 0;
}

.page-about .about-hero__frame {
  position: relative;
  padding: clamp(20px, 3.2vw, 44px);
  background:
    radial-gradient(120% 90% at 100% 0%, rgba(53, 224, 208, 0.10), transparent 55%),
    linear-gradient(180deg, rgba(255, 122, 26, 0.06), transparent 40%),
    var(--yk-deep);
  border: 1px solid var(--yk-line);
  box-shadow: var(--yk-shadow);
}

.page-about .about-hero__frame::before,
.page-about .about-hero__frame::after {
  content: "";
  position: absolute;
  width: 22px;
  height: 22px;
  border: 2px solid var(--yk-cyan);
}

.page-about .about-hero__frame::before {
  top: -1px;
  left: -1px;
  border-right: 0;
  border-bottom: 0;
}

.page-about .about-hero__frame::after {
  right: -1px;
  bottom: -1px;
  border-left: 0;
  border-top: 0;
}

.page-about .about-hero__grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: var(--about-gap);
}

.page-about .about-hero__eyebrow {
  margin: 0 0 14px;
  font-family: var(--yk-font-mono);
  font-size: 12px;
  letter-spacing: 0.14em;
  text-transform: uppercase;
  color: var(--yk-cyan);
}

.page-about .about-hero__eyebrow .yk-num {
  color: var(--yk-orange);
}

.page-about .about-hero__title {
  margin: 0 0 18px;
  color: var(--yk-paper);
}

.page-about .about-hero__lead {
  margin: 0 0 26px;
  max-width: 38em;
  color: rgba(244, 241, 232, 0.82);
}

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

.page-about .about-hero__aside {
  display: grid;
  gap: 16px;
}

.page-about .about-hero__media {
  margin: 0;
}

.page-about .about-hero__facts {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: 12px;
  margin: 0;
  padding: 14px 16px;
  border: 1px solid var(--yk-line-soft);
  background: rgba(35, 69, 60, 0.35);
}

.page-about .about-hero__facts dt {
  margin: 0 0 4px;
  font-size: 11px;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  color: var(--yk-mist);
}

.page-about .about-hero__facts dd {
  margin: 0;
  font-size: clamp(15px, 1.4vw, 17px);
  font-weight: 700;
  color: var(--yk-cyan);
}

.page-about .about-hero__facts dd .yk-num {
  font-family: var(--yk-font-mono);
  color: var(--yk-orange);
}

/* ---------- 章节头 ---------- */
.page-about .about-head {
  display: grid;
  grid-template-columns: auto 1fr;
  align-items: baseline;
  gap: 16px;
  margin-bottom: clamp(24px, 3vw, 40px);
  padding-bottom: 16px;
  border-bottom: 1px solid var(--yk-line);
}

.page-about .about-head__num {
  font-family: var(--yk-font-mono);
  font-size: clamp(28px, 5vw, 56px);
  font-weight: 700;
  line-height: 1;
  color: transparent;
  -webkit-text-stroke: 1.5px var(--yk-orange);
  letter-spacing: 0.02em;
}

.page-about .about-head__title {
  margin: 0;
  font-family: var(--yk-font-serif);
  font-weight: 700;
  font-size: clamp(22px, 3.2vw, 38px);
  line-height: 1.3;
  letter-spacing: -0.01em;
  color: var(--yk-paper);
}

.page-about .about-head--alt .about-head__num {
  -webkit-text-stroke-color: var(--yk-cyan);
}

/* ---------- 01 来历 ---------- */
.page-about .about-origin__grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: clamp(16px, 2vw, 24px);
  max-width: 62em;
}

.page-about .about-origin__grid .yk-prose {
  margin: 0;
  color: rgba(244, 241, 232, 0.88);
}

.page-about .about-origin__grid .yk-prose:first-child::first-letter {
  float: left;
  margin: 6px 10px 0 0;
  font-family: var(--yk-font-narrow);
  font-size: 3.4em;
  line-height: 0.86;
  color: var(--yk-orange);
}

/* ---------- 02 版本时间轴 ---------- */
.page-about .about-versions__lead {
  max-width: 46em;
  margin: 0 0 22px;
  color: rgba(244, 241, 232, 0.76);
}

.page-about .about-versions__bar {
  display: flex;
  gap: 8px;
  flex-wrap: wrap;
  margin-bottom: clamp(20px, 3vw, 32px);
}

.page-about .about-chip {
  padding: 10px 14px;
  min-height: 40px;
  font-family: var(--yk-font-mono);
  font-size: 12px;
  letter-spacing: 0.06em;
  color: var(--yk-mist);
  background: transparent;
  border: 1px solid var(--yk-line-soft);
  border-radius: var(--yk-radius);
  cursor: pointer;
  transition: color 200ms var(--yk-ease), border-color 200ms var(--yk-ease), background-color 200ms var(--yk-ease);
}

.page-about .about-chip:hover,
.page-about .about-chip:focus-visible {
  color: var(--yk-paper);
  border-color: var(--yk-cyan);
}

.page-about .about-chip.is-active {
  color: var(--yk-deep);
  background: var(--yk-cyan);
  border-color: var(--yk-cyan);
}

.page-about .about-versions__media {
  margin: 0 0 clamp(28px, 4vw, 48px);
}

.page-about .about-timeline {
  list-style: none;
  margin: 0;
  padding: 0;
  display: grid;
  gap: clamp(20px, 3vw, 30px);
}

.page-about .about-timeline__item {
  position: relative;
  padding-left: 26px;
  border-left: 2px solid var(--yk-turf);
}

.page-about .about-timeline__item::before {
  content: "";
  position: absolute;
  top: 8px;
  left: calc(-1 * 7px);
  width: 12px;
  height: 12px;
  background: var(--yk-orange);
  border-radius: 50%;
  box-shadow: 0 0 0 3px rgba(255, 122, 26, 0.18);
}

.page-about .about-timeline__marker {
  display: flex;
  align-items: baseline;
  gap: 10px;
  margin-bottom: 8px;
}

.page-about .about-timeline__code {
  font-family: var(--yk-font-mono);
  font-weight: 700;
  font-size: 22px;
  color: var(--yk-cyan);
  letter-spacing: 0.04em;
}

.page-about .about-timeline__era {
  font-family: var(--yk-font-mono);
  font-size: 11px;
  letter-spacing: 0.1em;
  text-transform: uppercase;
  color: var(--yk-mist);
}

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

.page-about .about-timeline__body p {
  margin: 0 0 12px;
  color: rgba(244, 241, 232, 0.82);
  max-width: 42em;
}

.page-about .about-timeline__facts {
  list-style: none;
  margin: 0;
  padding: 0;
  display: grid;
  gap: 6px;
}

.page-about .about-timeline__facts li {
  position: relative;
  padding-left: 18px;
  font-size: 14px;
  color: rgba(244, 241, 232, 0.72);
}

.page-about .about-timeline__facts li::before {
  content: "";
  position: absolute;
  top: 0.62em;
  left: 0;
  width: 8px;
  height: 2px;
  background: var(--yk-cyan);
}

.page-about .about-pull {
  position: relative;
  margin: clamp(32px, 4vw, 52px) 0 0;
  padding: clamp(22px, 3vw, 34px) clamp(22px, 3vw, 40px) clamp(22px, 3vw, 34px) clamp(30px, 4vw, 52px);
  background: var(--yk-paper);
  color: var(--yk-ink);
  border: 2px solid var(--yk-ink);
  box-shadow: 10px 10px 0 rgba(7, 26, 30, 0.55), -6px -6px 0 rgba(53, 224, 208, 0.22);
}

.page-about .about-pull::before {
  content: "";
  position: absolute;
  top: 0;
  left: 0;
  bottom: 0;
  width: 6px;
  background: var(--yk-red);
}

.page-about .about-pull p {
  margin: 0;
  font-family: var(--yk-font-serif);
  font-weight: 700;
  font-size: clamp(17px, 2.1vw, 24px);
  line-height: 1.55;
  letter-spacing: -0.01em;
}

/* ---------- 03 团队 ---------- */
.page-about .about-team__layout {
  display: grid;
  grid-template-columns: 1fr;
  gap: clamp(20px, 3vw, 40px);
}

.page-about .about-team__visual figure {
  margin: 0;
}

.page-about .about-team__content > p {
  margin: 0 0 20px;
  color: rgba(244, 241, 232, 0.86);
  max-width: 42em;
}

.page-about .about-team__bars {
  list-style: none;
  margin: 0;
  padding: 0;
}

.page-about .about-team__row {
  display: grid;
  grid-template-columns: 1fr auto;
  gap: 6px 16px;
  padding: 16px 0;
  border-bottom: 1px solid var(--yk-line-soft);
}

.page-about .about-team__row:first-child {
  border-top: 1px solid var(--yk-line-soft);
}

.page-about .about-team__role {
  margin: 0;
  font-weight: 700;
  color: var(--yk-paper);
}

.page-about .about-team__count {
  margin: 0;
  font-size: 14px;
  color: var(--yk-cyan);
  text-align: right;
}

.page-about .about-team__count .yk-num {
  font-family: var(--yk-font-mono);
  font-size: 18px;
  font-weight: 700;
  color: var(--yk-orange);
}

.page-about .about-team__track {
  display: block;
  grid-column: 1 / -1;
  height: 8px;
  background: var(--yk-turf);
  border-radius: 2px;
  overflow: hidden;
}

.page-about .about-team__fill {
  display: block;
  height: 100%;
  width: var(--about-w, 0%);
  background: linear-gradient(90deg, var(--yk-cyan), var(--yk-orange));
}

.page-about .about-team__note {
  grid-column: 1 / -1;
  margin: 0;
  font-size: 13px;
  line-height: 1.7;
  color: var(--yk-mist);
}

/* ---------- 04 流程 ---------- */
.page-about .about-flow__lead {
  max-width: 46em;
  margin: 0 0 clamp(22px, 3vw, 36px);
  color: rgba(244, 241, 232, 0.78);
}

.page-about .about-flow__steps {
  list-style: none;
  margin: 0;
  padding: 0;
  display: grid;
  grid-template-columns: 1fr;
  gap: 12px;
  counter-reset: about-flow;
}

.page-about .about-flow__step {
  position: relative;
  padding: 20px 20px 20px 24px;
  background: rgba(23, 26, 30, 0.75);
  border: 1px solid var(--yk-line-soft);
  border-left: 3px solid var(--yk-cyan);
}

.page-about .about-flow__index {
  display: block;
  font-family: var(--yk-font-mono);
  font-size: 12px;
  letter-spacing: 0.12em;
  color: var(--yk-orange);
  margin-bottom: 6px;
}

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

.page-about .about-flow__step p {
  margin: 0;
  font-size: 14.5px;
  line-height: 1.75;
  color: rgba(244, 241, 232, 0.78);
}

/* ---------- 05 原则 ---------- */
.page-about .about-principles__grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: 12px;
}

.page-about .about-principle {
  border: 1px solid var(--yk-line-soft);
  background: rgba(35, 69, 60, 0.22);
  transition: border-color 200ms var(--yk-ease), background-color 200ms var(--yk-ease);
}

.page-about .about-principle[open] {
  border-color: var(--yk-cyan);
  background: rgba(35, 69, 60, 0.42);
}

.page-about .about-principle summary {
  display: grid;
  grid-template-columns: auto 1fr;
  align-items: center;
  gap: 16px;
  padding: 18px 20px;
  cursor: pointer;
  list-style: none;
}

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

.page-about .about-principle summary::after {
  content: "+";
  grid-column: 2;
  justify-self: end;
  font-family: var(--yk-font-mono);
  font-size: 20px;
  color: var(--yk-orange);
}

.page-about .about-principle[open] summary::after {
  content: "–";
  color: var(--yk-cyan);
}

.page-about .about-principle__num {
  font-family: var(--yk-font-mono);
  font-size: 22px;
  font-weight: 700;
  color: var(--yk-cyan);
  line-height: 1;
}

.page-about .about-principle__title {
  font-family: var(--yk-font-serif);
  font-weight: 700;
  font-size: clamp(17px, 2vw, 22px);
  color: var(--yk-paper);
}

.page-about .about-principle p {
  margin: 0;
  padding: 0 20px 22px 58px;
  font-size: 14.5px;
  line-height: 1.8;
  color: rgba(244, 241, 232, 0.8);
}

/* ---------- 06 合作 ---------- */
.page-about .about-partners__layout {
  display: grid;
  grid-template-columns: 1fr;
  gap: clamp(20px, 3vw, 36px);
}

.page-about .about-partners__copy p {
  margin: 0 0 18px;
  color: rgba(244, 241, 232, 0.84);
  max-width: 42em;
}

.page-about .about-partners__facts {
  list-style: none;
  margin: 24px 0 0;
  padding: 0;
  display: grid;
  gap: 10px;
}

.page-about .about-partners__facts li {
  padding: 12px 16px;
  border: 1px solid var(--yk-line-soft);
  background: rgba(7, 26, 30, 0.55);
  font-size: 14.5px;
  color: rgba(244, 241, 232, 0.86);
}

.page-about .about-partners__facts .yk-num {
  font-family: var(--yk-font-mono);
  font-weight: 700;
  font-size: 17px;
  color: var(--yk-amber);
}

.page-about .about-partners__rail {
  position: relative;
  height: 48px;
  border-top: 1px dashed var(--yk-line-soft);
  border-bottom: 1px dashed var(--yk-line-soft);
}

.page-about .about-partners__tick {
  position: absolute;
  top: -1px;
  bottom: -1px;
  left: var(--about-pos, 0%);
  width: 2px;
  background: var(--yk-cyan);
}

.page-about .about-partners__tick:nth-child(3) {
  background: var(--yk-orange);
}

/* ---------- 07 CTA ---------- */
.page-about .about-cta__grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: 14px;
}

.page-about .about-cta__card {
  display: flex;
  flex-direction: column;
  gap: 12px;
  padding: 22px 22px 24px;
  background: var(--yk-paper);
  color: var(--yk-ink);
  border: 2px solid var(--yk-ink);
  box-shadow: 8px 8px 0 rgba(7, 26, 30, 0.55);
  text-decoration: none;
  transition: transform 200ms var(--yk-ease), box-shadow 200ms var(--yk-ease);
}

.page-about .about-cta__card:hover,
.page-about .about-cta__card:focus-visible {
  transform: translate(-2px, -2px);
  box-shadow: 12px 12px 0 rgba(255, 122, 26, 0.55);
}

.page-about .about-cta__card h3 {
  margin: 0;
  color: var(--yk-ink);
}

.page-about .about-cta__card p {
  margin: 0;
  font-size: 14.5px;
  line-height: 1.75;
  color: #2f3733;
}

.page-about .about-cta__go {
  margin-top: auto;
  font-family: var(--yk-font-mono);
  font-size: 12px;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  color: var(--yk-red);
}

.page-about .about-cta__foot {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
  margin-top: clamp(22px, 3vw, 34px);
}

/* ---------- 响应式 ---------- */
@media (min-width: 720px) {
  .page-about .about-origin__grid {
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }

  .page-about .about-origin__grid .yk-prose:first-child {
    grid-column: 1 / -1;
  }

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

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

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

@media (min-width: 900px) {
  .page-about .about-hero__grid {
    grid-template-columns: minmax(0, 1.25fr) minmax(0, 1fr);
    gap: clamp(32px, 4vw, 64px);
    align-items: start;
  }

  .page-about .about-team__layout {
    grid-template-columns: minmax(0, 1fr) minmax(0, 1.15fr);
    align-items: start;
  }

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

  .page-about .about-timeline__item {
    display: grid;
    grid-template-columns: 180px minmax(0, 1fr);
    gap: clamp(20px, 3vw, 40px);
    padding-left: 0;
    padding-top: 22px;
    border-left: 0;
    border-top: 2px solid var(--yk-turf);
  }

  .page-about .about-timeline__item::before {
    top: -7px;
    left: 0;
  }

  .page-about .about-timeline__marker {
    flex-direction: column;
    gap: 4px;
  }

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

  .page-about .about-flow__steps {
    grid-template-columns: repeat(4, minmax(0, 1fr));
  }

  .page-about .about-partners__layout {
    grid-template-columns: minmax(0, 1.6fr) minmax(0, 1fr);
    align-items: center;
  }
}

@media (min-width: 1024px) {
  .page-about .about-hero__aside {
    grid-template-rows: auto auto;
  }
}

@media (prefers-reduced-motion: reduce) {
  .page-about .about-chip,
  .page-about .about-principle,
  .page-about .about-cta__card {
    transition: none;
  }
  .page-about .about-cta__card:hover,
  .page-about .about-cta__card:focus-visible {
    transform: none;
  }
}
</final>

.page-about {
  --about-pos: var(--about-shell);
  --about-w: var(--about-gap);
}