.page-about {
  padding-bottom: clamp(56px, 9vw, 128px);
}

/* ---------- 面包屑 ---------- */
.page-about .breadcrumb {
  padding-top: clamp(18px, 3vw, 34px);
  margin-bottom: clamp(20px, 4vw, 36px);
}

/* ---------- 首屏分屏 ---------- */
.page-about .about-hero {
  padding-bottom: clamp(36px, 6vw, 84px);
}

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

.page-about .about-hero__copy {
  min-width: 0;
}

.page-about .about-hero h1 {
  font-family: var(--f-display);
  font-weight: 700;
  font-size: clamp(1.9rem, 6.8vw, 3.4rem);
  line-height: 1.08;
  letter-spacing: -0.03em;
  color: var(--white);
  margin: 16px 0 0;
  max-width: 17ch;
}

.page-about .about-lede {
  margin: 20px 0 0;
  max-width: 46ch;
  font-size: clamp(1rem, 2.4vw, 1.1rem);
  line-height: 1.85;
  color: var(--paper);
}

.page-about .about-hero__meta {
  display: flex;
  flex-wrap: wrap;
  gap: 8px 20px;
  margin-top: 26px;
  padding-top: 16px;
  border-top: 1px solid var(--line);
}

.page-about .about-chip {
  font-family: var(--f-mono);
  font-size: 12px;
  letter-spacing: 0.08em;
  color: var(--cyan);
}

.page-about .about-hero__note {
  margin: 18px 0 0;
  font-size: 14px;
  line-height: 1.8;
  color: var(--muted);
  max-width: 48ch;
}

.page-about .about-hero__note a {
  color: var(--cyan);
  text-decoration: none;
  border-bottom: 1px solid rgba(47, 243, 210, 0.35);
  transition: border-color 0.18s var(--ease);
}

.page-about .about-hero__note a:hover,
.page-about .about-hero__note a:focus-visible {
  border-bottom-color: var(--cyan);
}

.page-about .about-hero__visual {
  position: relative;
  margin: 0;
  min-width: 0;
}

.page-about .about-hero__visual img {
  display: block;
  width: 100%;
  height: auto;
  max-width: 100%;
  aspect-ratio: 3 / 2;
  object-fit: cover;
  filter: saturate(0.8) brightness(0.88);
}

.page-about .about-hero__visual::before {
  content: "";
  position: absolute;
  top: 10px;
  right: 10px;
  width: 56px;
  height: 56px;
  border-top: 1px solid var(--cyan);
  border-right: 1px solid var(--cyan);
  opacity: 0.65;
  pointer-events: none;
}

.page-about .about-hero__cap {
  margin-top: 12px;
  font-family: var(--f-mono);
  font-size: 12px;
  line-height: 1.7;
  letter-spacing: 0.04em;
  color: var(--muted);
}

/* ---------- 索引带 ---------- */
.page-about .about-toc {
  border-top: 1px solid var(--line);
  border-bottom: 1px solid var(--line);
  padding: 12px 0;
}

.page-about .about-toc__row {
  display: flex;
  align-items: center;
  gap: 20px;
  overflow-x: auto;
  white-space: nowrap;
  scrollbar-width: thin;
  -webkit-overflow-scrolling: touch;
}

.page-about .about-toc__label {
  flex: none;
  font-family: var(--f-mono);
  font-size: 11px;
  letter-spacing: 0.14em;
  color: var(--muted);
}

.page-about .about-toc__link {
  flex: none;
  font-family: var(--f-mono);
  font-size: 12.5px;
  letter-spacing: 0.06em;
  color: var(--paper);
  text-decoration: none;
  padding-bottom: 2px;
  border-bottom: 1px solid transparent;
  transition: color 0.18s var(--ease), border-color 0.18s var(--ease);
}

.page-about .about-toc__link:hover,
.page-about .about-toc__link:focus-visible {
  color: var(--cyan);
  border-bottom-color: var(--cyan);
}

/* ---------- 通用区块骨架 ---------- */
.page-about .about-block {
  padding: clamp(44px, 7vw, 100px) 0;
}

.page-about .about-block + .about-block {
  border-top: 1px solid var(--line);
}

.page-about .about-block__grid {
  display: grid;
  grid-template-columns: 1fr;
}

.page-about .about-block__aside {
  display: flex;
  align-items: baseline;
  gap: 14px;
  margin-bottom: 18px;
}

.page-about .about-no {
  font-family: var(--f-mono);
  font-weight: 700;
  font-size: clamp(1.5rem, 4.6vw, 2.2rem);
  line-height: 1;
  letter-spacing: -0.02em;
  color: var(--cyan);
}

.page-about .about-kicker {
  font-family: var(--f-mono);
  font-size: 11.5px;
  letter-spacing: 0.16em;
  color: var(--muted);
}

.page-about .about-block__body {
  min-width: 0;
}

.page-about .about-block__title {
  font-family: var(--f-display);
  font-weight: 700;
  font-size: clamp(1.45rem, 3.8vw, 2.3rem);
  line-height: 1.2;
  letter-spacing: -0.02em;
  color: var(--white);
  margin: 0 0 20px;
  max-width: 20ch;
}

.page-about .about-block__body .prose {
  max-width: 62ch;
}

.page-about .prose p {
  margin: 0 0 1.05em;
}

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

/* ---------- 规模数字网格 ---------- */
.page-about .about-stats {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 1px;
  background: var(--line);
  border: 1px solid var(--line);
  margin-top: clamp(24px, 4vw, 40px);
}

.page-about .about-stats__item {
  display: flex;
  flex-direction: column;
  gap: 10px;
  background: var(--panel);
  padding: clamp(16px, 3vw, 26px);
  transition: background 0.18s var(--ease);
}

.page-about .about-stats__item:hover,
.page-about .about-stats__item:focus-within {
  background: var(--panel-deep);
}

.page-about .about-stats__num {
  font-family: var(--f-mono);
  font-weight: 700;
  font-size: clamp(1.55rem, 4.2vw, 2.5rem);
  line-height: 1;
  letter-spacing: -0.03em;
  color: var(--white);
}

.page-about .about-stats__num--cyan {
  color: var(--cyan);
}

.page-about .about-stats__num--amber {
  color: var(--amber);
}

.page-about .about-stats__key {
  font-size: 13.5px;
  line-height: 1.6;
  color: var(--paper);
}

.page-about .about-stats__gloss,
.page-about .about-stats__num-note {
  font-family: var(--f-mono);
  font-size: 11.5px;
  line-height: 1.65;
  letter-spacing: 0.02em;
  color: var(--muted);
  transition: color 0.18s var(--ease);
}

.page-about .about-stats__item:hover .about-stats__gloss,
.page-about .about-stats__item:hover .about-stats__num-note,
.page-about .about-stats__item:focus-within .about-stats__gloss,
.page-about .about-stats__item:focus-within .about-stats__num-note {
  color: var(--cyan);
}

/* ---------- 流程折叠 ---------- */
.page-about .about-flow {
  list-style: none;
  margin: clamp(24px, 4vw, 38px) 0 0;
  padding: 0;
}

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

.page-about .about-step {
  border-top: 1px solid var(--line);
}

.page-about .about-flow__item:last-child .about-step {
  border-bottom: 1px solid var(--line);
}

.page-about .about-step__sum {
  display: flex;
  align-items: center;
  gap: 14px;
  padding: 16px 0;
  cursor: pointer;
  list-style: none;
}

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

.page-about .about-step__no {
  flex: none;
  width: 26px;
  font-family: var(--f-mono);
  font-size: 12px;
  letter-spacing: 0.08em;
  color: var(--cyan);
}

.page-about .about-step__t {
  font-family: var(--f-display);
  font-weight: 700;
  font-size: clamp(1rem, 2.6vw, 1.15rem);
  letter-spacing: -0.01em;
  color: var(--white);
  transition: color 0.18s var(--ease);
}

.page-about .about-step__sum:hover .about-step__t,
.page-about .about-step__sum:focus-visible .about-step__t {
  color: var(--cyan);
}

.page-about .about-step__sign {
  position: relative;
  flex: none;
  margin-left: auto;
  width: 12px;
  height: 12px;
}

.page-about .about-step__sign::before,
.page-about .about-step__sign::after {
  content: "";
  position: absolute;
  left: 0;
  right: 0;
  top: 50%;
  height: 1px;
  background: var(--cyan);
  transition: transform 0.2s var(--ease);
}

.page-about .about-step__sign::after {
  transform: rotate(90deg);
}

.page-about .about-step[open] .about-step__sign::after {
  transform: rotate(0deg);
}

.page-about .about-step__body {
  padding: 0 0 20px 40px;
  max-width: 60ch;
}

.page-about .about-step__body p {
  margin: 0;
  font-size: 15px;
  line-height: 1.85;
  color: var(--paper);
}

/* ---------- 配图 ---------- */
.page-about .about-figure {
  margin: clamp(26px, 4vw, 46px) 0 0;
  max-width: 780px;
}

.page-about .about-figure img {
  display: block;
  width: 100%;
  height: auto;
  max-width: 100%;
  object-fit: cover;
  filter: saturate(0.82) brightness(0.9);
}

.page-about .about-figure__cap {
  margin-top: 10px;
  font-family: var(--f-mono);
  font-size: 11.5px;
  line-height: 1.7;
  letter-spacing: 0.04em;
  color: var(--muted);
}

/* ---------- 版本时间轴 ---------- */
.page-about .about-vers {
  margin: clamp(24px, 4vw, 38px) 0 0;
  max-width: 720px;
}

.page-about .about-vers__row {
  position: relative;
  padding: 0 0 26px 22px;
  border-left: 1px solid var(--line);
}

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

.page-about .about-vers__row::before {
  content: "";
  position: absolute;
  left: -1px;
  top: 5px;
  width: 9px;
  height: 9px;
  background: var(--cyan);
}

.page-about .about-vers__tag {
  font-family: var(--f-mono);
  font-weight: 700;
  font-size: 13px;
  letter-spacing: 0.06em;
  color: var(--cyan);
}

.page-about .about-vers__txt {
  margin: 8px 0 0;
  font-size: 15px;
  line-height: 1.8;
  color: var(--paper);
  max-width: 56ch;
}

/* ---------- 团队分工 ---------- */
.page-about .about-team {
  display: grid;
  grid-template-columns: 1fr;
  border-top: 1px solid var(--line);
  margin-top: clamp(24px, 4vw, 38px);
}

.page-about .about-team__item {
  display: grid;
  grid-template-columns: 62px minmax(0, 1fr);
  gap: 6px 16px;
  padding: 20px 0;
  border-bottom: 1px solid var(--line);
  align-items: start;
}

.page-about .about-team__num {
  grid-row: 1 / span 2;
  font-family: var(--f-mono);
  font-weight: 700;
  font-size: clamp(1.7rem, 4.4vw, 2.3rem);
  line-height: 1;
  letter-spacing: -0.03em;
  color: var(--amber);
}

.page-about .about-team__name {
  font-family: var(--f-mono);
  font-size: 12px;
  letter-spacing: 0.1em;
  color: var(--cyan);
  align-self: end;
}

.page-about .about-team__desc {
  grid-column: 2;
  margin: 6px 0 0;
  font-size: 14px;
  line-height: 1.75;
  color: var(--paper);
  max-width: 48ch;
}

.page-about .about-team__foot {
  margin-top: clamp(20px, 3vw, 30px);
  padding-left: 14px;
  border-left: 1px solid var(--cyan);
}

/* ---------- 规范表 ---------- */
.page-about .about-standards {
  margin-top: clamp(24px, 4vw, 36px);
  border-top: 1px solid var(--line);
}

.page-about .about-standards__row {
  display: grid;
  grid-template-columns: 1fr;
  gap: 8px;
  padding: 18px 0;
  border-bottom: 1px solid var(--line);
}

.page-about .about-standards__k {
  font-family: var(--f-mono);
  font-size: 12px;
  letter-spacing: 0.1em;
  color: var(--cyan);
}

.page-about .about-standards__v {
  font-size: 15px;
  line-height: 1.8;
  color: var(--paper);
  max-width: 58ch;
}

/* ---------- 尾部入口 ---------- */
.page-about .about-next {
  margin-top: clamp(40px, 6vw, 76px);
  padding-top: clamp(26px, 4vw, 44px);
  border-top: 1px solid var(--line);
}

.page-about .about-next__lead {
  margin: 0 0 18px;
  font-family: var(--f-display);
  font-weight: 700;
  font-size: clamp(1.05rem, 2.6vw, 1.3rem);
  letter-spacing: -0.01em;
  color: var(--white);
}

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

/* ---------- 断点 ---------- */
@media (min-width: 760px) {
  .page-about .about-stats {
    grid-template-columns: repeat(3, minmax(0, 1fr));
  }

  .page-about .about-team {
    grid-template-columns: repeat(2, minmax(0, 1fr));
    column-gap: clamp(28px, 4vw, 56px);
  }

  .page-about .about-team__item:nth-last-child(-n + 2) {
    border-bottom: 1px solid var(--line);
  }

  .page-about .about-standards__row {
    grid-template-columns: 150px minmax(0, 1fr);
    gap: 24px;
    align-items: baseline;
  }
}

@media (min-width: 900px) {
  .page-about .about-hero__visual::before {
    top: -14px;
    right: -14px;
    width: 72px;
    height: 72px;
  }
}

@media (min-width: 1000px) {
  .page-about .about-hero__grid {
    grid-template-columns: minmax(0, 1.05fr) minmax(0, 0.95fr);
    gap: clamp(36px, 5vw, 76px);
  }

  .page-about .about-block__grid {
    grid-template-columns: 116px minmax(0, 1fr);
    gap: clamp(28px, 4vw, 68px);
    align-items: start;
  }

  .page-about .about-block__aside {
    display: block;
    margin-bottom: 0;
    position: sticky;
    top: 84px;
  }

  .page-about .about-no {
    display: block;
    font-size: 2.4rem;
  }

  .page-about .about-kicker {
    display: block;
    margin-top: 12px;
  }
}

@media (prefers-reduced-motion: reduce) {
  .page-about .about-step__sign::before,
  .page-about .about-step__sign::after,
  .page-about .about-step__t,
  .page-about .about-stats__item,
  .page-about .about-stats__gloss,
  .page-about .about-stats__num-note,
  .page-about .about-toc__link,
  .page-about .about-hero__note a {
    transition: none;
  }
}