.page-about {
  --about-num: clamp(56px, 9vw, 116px);
  --about-line: rgba(90, 125, 147, 0.32);
  --about-gap: clamp(56px, 8vw, 104px);
  background:
    radial-gradient(900px 460px at 90% -80px, rgba(53, 224, 208, 0.1), transparent 70%),
    radial-gradient(680px 400px at -12% 36%, rgba(255, 122, 89, 0.07), transparent 68%),
    var(--c-ink);
  color: var(--c-mist);
}

.page-about [id] {
  scroll-margin-top: 104px;
}

/* ---------- 面包屑 ---------- */
.about-top {
  padding-top: clamp(96px, 12vw, 138px);
}

.about-crumbs {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 8px;
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.06em;
  color: var(--c-slate);
}

.about-crumbs .crumbs__link {
  color: var(--c-slate);
  text-decoration: none;
  border-bottom: 1px solid transparent;
  transition: color 0.25s var(--ease), border-color 0.25s var(--ease);
}

.about-crumbs .crumbs__link:hover {
  color: var(--c-cyan);
  border-bottom-color: var(--c-cyan);
}

.about-crumbs__current {
  color: var(--c-sand);
}

/* ---------- 首屏 ---------- */
.about-hero {
  position: relative;
  overflow: clip;
  padding: clamp(28px, 4vw, 44px) 0 clamp(40px, 6vw, 72px);
}

.about-hero::before {
  content: "";
  position: absolute;
  right: -8%;
  top: 4%;
  width: min(46vw, 520px);
  aspect-ratio: 1 / 1;
  background: linear-gradient(140deg, rgba(53, 224, 208, 0.16), rgba(255, 122, 89, 0.06) 62%, transparent 78%);
  clip-path: polygon(0 0, 100% 0, 100% 74%, 22% 100%);
  pointer-events: none;
}

.about-hero__inner {
  position: relative;
  display: grid;
  gap: clamp(32px, 5vw, 56px);
  align-items: end;
}

.about-hero__copy {
  max-width: 40em;
}

.about-hero__title {
  margin: 18px 0 0;
  font-family: var(--font-sans);
  font-weight: 800;
  font-size: clamp(2rem, 5.2vw, 3.75rem);
  line-height: 1.04;
  letter-spacing: -0.02em;
  color: var(--c-mist);
}

.about-hero__mark {
  color: var(--c-cyan);
  border-bottom: 3px solid rgba(255, 122, 89, 0.7);
  padding-bottom: 2px;
}

.about-hero__lede {
  margin: 24px 0 0;
  max-width: 34em;
  font-size: clamp(1rem, 1.5vw, 1.1rem);
  line-height: 1.85;
  color: var(--c-slate);
}

.about-hero__meta {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: 16px;
  margin: 32px 0 0;
  padding-top: 22px;
  border-top: 1px solid var(--about-line);
}

.about-hero__meta-item {
  min-width: 0;
}

.about-hero__meta-label {
  display: block;
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: 0.08em;
  color: var(--c-slate);
  margin-bottom: 6px;
}

.about-hero__meta-num {
  margin: 0;
  font-family: var(--font-mono);
  font-size: clamp(1.35rem, 2.6vw, 1.9rem);
  line-height: 1;
  color: var(--c-cyan);
  letter-spacing: -0.02em;
}

.about-hero__meta-num small {
  font-size: 0.62em;
  margin-left: 2px;
}

.about-hero__meta-num--text {
  color: var(--c-sand);
  font-family: var(--font-sans);
  font-weight: 700;
  letter-spacing: 0.02em;
}

.about-hero__figure {
  margin: 0;
  border: 1px solid rgba(53, 224, 208, 0.22);
}

/* ---------- 章节索引 ---------- */
.about-index {
  display: flex;
  gap: 8px;
  overflow-x: auto;
  scrollbar-width: none;
  padding-bottom: 18px;
  border-bottom: 1px solid var(--about-line);
}

.about-index::-webkit-scrollbar {
  display: none;
}

.about-index__link {
  flex: 0 0 auto;
  display: inline-flex;
  align-items: baseline;
  gap: 8px;
  padding: 9px 15px;
  border: 1px solid var(--about-line);
  border-radius: 999px;
  font-size: 13px;
  color: var(--c-slate);
  text-decoration: none;
  transition: color 0.25s var(--ease), border-color 0.25s var(--ease), background-color 0.25s var(--ease);
}

.about-index__link:hover,
.about-index__link:focus-visible {
  color: var(--c-ink);
  background: var(--c-cyan);
  border-color: var(--c-cyan);
}

.about-index__num {
  font-family: var(--font-mono);
  font-size: 11px;
  color: var(--c-sand);
}

.about-index__link:hover .about-index__num,
.about-index__link:focus-visible .about-index__num {
  color: var(--c-ink);
}

/* ---------- 章节骨架 ---------- */
.about-chapter {
  padding: var(--about-gap) 0;
  border-top: 1px solid var(--about-line);
}

.about-chapter__inner {
  display: grid;
  gap: 24px;
}

.about-chapter__marker {
  display: flex;
  align-items: baseline;
  gap: 14px;
}

.about-chapter__num {
  font-family: var(--font-sans);
  font-weight: 800;
  font-size: var(--about-num);
  line-height: 0.82;
  letter-spacing: -0.05em;
  color: rgba(53, 224, 208, 0.14);
  -webkit-text-stroke: 1px rgba(53, 224, 208, 0.5);
}

.about-chapter__label {
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: 0.14em;
  color: var(--c-sand);
  white-space: nowrap;
}

.about-chapter__content {
  min-width: 0;
}

.about-chapter__kicker {
  margin: 0;
  font-family: var(--font-serif);
  font-style: italic;
  font-size: clamp(0.98rem, 1.5vw, 1.12rem);
  color: var(--c-sand);
  letter-spacing: 0.01em;
}

.about-chapter__title {
  margin: 14px 0 0;
  font-family: var(--font-sans);
  font-weight: 800;
  font-size: clamp(1.45rem, 3.1vw, 2.25rem);
  line-height: 1.2;
  letter-spacing: -0.02em;
  color: var(--c-mist);
  max-width: 24em;
}

.about-prose {
  max-width: 66ch;
  margin-top: 22px;
}

.about-prose p {
  margin: 0 0 18px;
  font-size: clamp(0.98rem, 1.2vw, 1.05rem);
  line-height: 1.85;
  color: var(--c-mist);
}

.about-prose p:last-child {
  margin-bottom: 0;
}

/* ---------- 品牌坐标数据条 ---------- */
.about-facts {
  list-style: none;
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(160px, 1fr));
  gap: 12px;
  margin: 32px 0 0;
  padding: 0;
}

.about-facts__item {
  display: flex;
  flex-direction: column;
  gap: 8px;
  padding: 18px 20px;
  background: var(--c-panel);
  border-left: 2px solid var(--c-cyan);
  clip-path: polygon(0 0, calc(100% - 16px) 0, 100% 16px, 100% 100%, 0 100%);
}

.about-facts__key {
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: 0.08em;
  color: var(--c-slate);
}

.about-facts__val {
  font-size: clamp(1rem, 1.5vw, 1.15rem);
  font-weight: 700;
  color: var(--c-mist);
  letter-spacing: -0.01em;
}

/* ---------- 发展时间线 ---------- */
.about-timeline {
  list-style: none;
  margin: 36px 0 0;
  padding: 0;
  display: grid;
  gap: 30px;
}

.about-timeline__item {
  position: relative;
  padding-left: 34px;
}

.about-timeline__item::before {
  content: "";
  position: absolute;
  left: 5px;
  top: 22px;
  bottom: -30px;
  width: 2px;
  background: linear-gradient(180deg, rgba(53, 224, 208, 0.65), rgba(90, 125, 147, 0.16));
  transform: skewX(-5deg);
  transform-origin: top center;
}

.about-timeline__item:last-child::before {
  display: none;
}

.about-timeline__item::after {
  content: "";
  position: absolute;
  left: 0;
  top: 7px;
  width: 12px;
  height: 12px;
  background: var(--c-cyan);
  clip-path: polygon(50% 0, 100% 50%, 50% 100%, 0 50%);
  box-shadow: 0 0 14px rgba(53, 224, 208, 0.5);
}

.about-timeline__head {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 10px;
}

.about-timeline__stamp {
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: 0.1em;
  color: var(--c-slate);
}

.about-timeline__title {
  margin: 12px 0 8px;
  font-family: var(--font-sans);
  font-size: clamp(1.05rem, 1.8vw, 1.28rem);
  font-weight: 700;
  letter-spacing: -0.01em;
  color: var(--c-mist);
}

.about-timeline__text {
  margin: 0;
  max-width: 58ch;
  font-size: 0.96rem;
  line-height: 1.8;
  color: var(--c-slate);
}

/* ---------- 变更说明 ---------- */
.about-changes__figure {
  margin: 32px 0 28px;
  border: 1px solid rgba(232, 196, 138, 0.26);
}

.about-changes {
  display: grid;
  gap: 10px;
}

.about-change {
  background: var(--c-panel);
  border: 1px solid var(--about-line);
  clip-path: polygon(0 0, calc(100% - 16px) 0, 100% 16px, 100% 100%, 16px 100%, 0 calc(100% - 16px));
  transition: border-color 0.3s var(--ease), background-color 0.3s var(--ease);
}

.about-change[open] {
  border-color: rgba(53, 224, 208, 0.4);
  background: var(--c-ink-2);
}

.about-change__summary {
  display: grid;
  grid-template-columns: auto minmax(0, 1fr) auto;
  align-items: center;
  gap: 14px;
  padding: 16px 20px;
  cursor: pointer;
  list-style: none;
}

.about-change__summary::-webkit-details-marker {
  display: none;
}

.about-change__no {
  font-family: var(--font-mono);
  font-size: 13px;
  color: var(--c-sand);
  letter-spacing: 0.04em;
}

.about-change__title {
  font-size: 0.98rem;
  font-weight: 600;
  line-height: 1.5;
  color: var(--c-mist);
}

.about-change__chev {
  width: 9px;
  height: 9px;
  border-right: 2px solid var(--c-cyan);
  border-bottom: 2px solid var(--c-cyan);
  transform: rotate(45deg);
  transition: transform 0.3s var(--ease);
}

.about-change[open] .about-change__chev {
  transform: rotate(225deg);
}

.about-change__body {
  padding: 0 20px 20px;
  border-top: 1px solid rgba(90, 125, 147, 0.24);
  margin-top: 4px;
  padding-top: 16px;
}

.about-change__body p {
  margin: 0 0 12px;
  max-width: 60ch;
  font-size: 0.94rem;
  line-height: 1.8;
  color: var(--c-slate);
}

.about-change__meta {
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: 0.04em;
  color: var(--c-teal);
  margin-bottom: 0;
}

/* ---------- 团队与生产 ---------- */
.about-team {
  display: grid;
  gap: 24px;
  margin-top: 32px;
  align-items: start;
}

.about-team__figure {
  margin: 0;
  border: 1px solid rgba(53, 224, 208, 0.2);
}

.about-team__panels {
  display: grid;
  gap: 12px;
}

.about-team__panel {
  display: flex;
  flex-direction: column;
  gap: 6px;
  padding: 20px 22px;
  background: var(--c-panel);
  border-left: 2px solid var(--c-coral);
}

.about-team__num {
  font-family: var(--font-mono);
  font-size: clamp(1.7rem, 3.4vw, 2.4rem);
  line-height: 1;
  color: var(--c-cyan);
  letter-spacing: -0.03em;
}

.about-team__label {
  font-size: 0.86rem;
  line-height: 1.6;
  color: var(--c-slate);
}

/* ---------- 协作流程 ---------- */
.about-flow {
  list-style: none;
  display: grid;
  gap: 12px;
  margin: 32px 0 0;
  padding: 0;
}

.about-flow__step {
  position: relative;
  padding: 22px 22px 20px;
  background: linear-gradient(160deg, rgba(16, 40, 59, 0.95), rgba(11, 34, 57, 0.92));
  border-top: 1px solid rgba(53, 224, 208, 0.26);
  transition: transform 0.3s var(--ease), border-color 0.3s var(--ease);
}

.about-flow__step:hover {
  transform: translateY(-3px);
  border-top-color: var(--c-cyan);
}

.about-flow__no {
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: 0.12em;
  color: var(--c-sand);
}

.about-flow__title {
  margin: 10px 0 8px;
  font-family: var(--font-sans);
  font-size: 1.06rem;
  font-weight: 700;
  letter-spacing: -0.01em;
  color: var(--c-mist);
}

.about-flow__text {
  margin: 0;
  font-size: 0.92rem;
  line-height: 1.78;
  color: var(--c-slate);
}

/* ---------- 运营中心与联系 ---------- */
.about-chapter--contact {
  border-top: 1px solid var(--about-line);
}

.about-contact {
  display: grid;
  gap: 20px;
  margin-top: 32px;
}

.about-contact__card {
  padding: 26px 24px;
  background: var(--c-panel);
  border: 1px solid rgba(53, 224, 208, 0.26);
}

.about-contact__mark {
  display: block;
  margin-bottom: 16px;
}

.about-contact__place {
  margin: 0 0 8px;
  font-size: clamp(1.02rem, 1.7vw, 1.2rem);
  font-weight: 700;
  color: var(--c-mist);
  letter-spacing: -0.01em;
}

.about-contact__sub {
  margin: 0;
  font-size: 0.9rem;
  line-height: 1.75;
  color: var(--c-slate);
}

.about-contact__list {
  margin: 0;
  display: grid;
  gap: 0;
  border-top: 1px solid var(--about-line);
}

.about-contact__row {
  display: grid;
  gap: 4px;
  padding: 14px 0;
  border-bottom: 1px solid var(--about-line);
}

.about-contact__key {
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: 0.1em;
  color: var(--c-sand);
}

.about-contact__val {
  margin: 0;
  font-size: 0.95rem;
  line-height: 1.7;
  color: var(--c-mist);
  word-break: break-word;
}

.about-contact__note {
  margin: 20px 0 0;
  max-width: 60ch;
  padding-left: 14px;
  border-left: 2px solid var(--c-coral);
  font-size: 0.9rem;
  line-height: 1.8;
  color: var(--c-slate);
}

/* ---------- 收束区 ---------- */
.about-next {
  padding: clamp(44px, 6vw, 76px) 0 clamp(60px, 8vw, 100px);
  border-top: 1px solid var(--about-line);
  background: linear-gradient(180deg, rgba(11, 34, 57, 0) 0%, var(--c-ink-2) 100%);
}

.about-next__inner {
  display: grid;
  gap: 24px;
}

.about-next__title {
  margin: 0;
  font-family: var(--font-sans);
  font-weight: 800;
  font-size: clamp(1.3rem, 2.6vw, 1.85rem);
  letter-spacing: -0.02em;
  line-height: 1.25;
  color: var(--c-mist);
  max-width: 20em;
}

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

/* ---------- 响应式 ---------- */
@media (min-width: 640px) {
  .about-team__panels {
    grid-template-columns: repeat(3, minmax(0, 1fr));
  }

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

  .about-contact__row {
    grid-template-columns: 120px minmax(0, 1fr);
    align-items: baseline;
    gap: 16px;
  }
}

@media (min-width: 880px) {
  .about-chapter__inner {
    grid-template-columns: 176px minmax(0, 1fr);
    gap: clamp(32px, 4vw, 56px);
    align-items: start;
  }

  .about-chapter__marker {
    flex-direction: column;
    align-items: flex-start;
    gap: 12px;
    position: sticky;
    top: 108px;
  }

  .about-hero__inner {
    grid-template-columns: minmax(0, 1.08fr) minmax(0, 0.92fr);
  }

  .about-hero__figure {
    margin-top: 12px;
  }

  .about-team {
    grid-template-columns: minmax(0, 1.1fr) minmax(0, 0.9fr);
    gap: 28px;
  }

  .about-team__panels {
    grid-template-columns: minmax(0, 1fr);
  }

  .about-contact {
    grid-template-columns: minmax(0, 0.85fr) minmax(0, 1.15fr);
    gap: 28px;
    align-items: start;
  }

  .about-next__inner {
    grid-template-columns: minmax(0, 1fr) auto;
    align-items: end;
    gap: 32px;
  }

  .about-next__links {
    justify-content: flex-end;
  }
}

@media (min-width: 1080px) {
  .about-flow {
    grid-template-columns: repeat(3, minmax(0, 1fr));
  }
}

@media (prefers-reduced-motion: reduce) {
  .page-about .about-flow__step,
  .page-about .about-index__link,
  .page-about .about-change,
  .page-about .about-change__chev {
    transition-duration: 0.01ms;
  }

  .page-about .about-flow__step:hover {
    transform: none;
  }
}