.page-about {
  --about-pad: clamp(2.5rem, 7vw, 5.5rem);
  background: var(--ink-950);
  color: var(--mist-100);
  font-family: var(--font-body);
  overflow-x: clip;
}

.page-about .about-crumb {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 0.45rem;
  padding-top: 1.5rem;
  font-family: var(--font-mono);
  font-size: 0.72rem;
  letter-spacing: 0.1em;
  color: var(--steel-500);
}

.page-about .about-crumb a {
  color: var(--mist-300);
  text-decoration: none;
  transition: color 0.2s var(--ease);
}

.page-about .about-crumb a:hover,
.page-about .about-crumb a:focus-visible {
  color: var(--cyan-400);
}

/* ---------- 品牌自述 ---------- */
.page-about .about-lede {
  padding: clamp(2rem, 5vw, 3.5rem) 0 var(--about-pad);
}

.page-about .about-lede__grid {
  display: grid;
  gap: clamp(1.75rem, 4vw, 3rem);
}

.page-about .about-lede h1 {
  margin: 0.9rem 0 0;
  font-family: var(--font-display);
  font-weight: 900;
  font-size: clamp(2rem, 7vw, 4rem);
  line-height: 1.08;
  letter-spacing: 0.04em;
  color: var(--mist-100);
}

.page-about .about-lede__body p {
  margin: 0 0 1.15rem;
  max-width: 64ch;
  font-size: 0.98rem;
  line-height: 1.9;
  color: var(--mist-300);
}

.page-about .about-lede__body .about-lede__lead {
  margin-bottom: 1.4rem;
  padding-left: 1.1rem;
  border-left: 2px solid var(--cyan-400);
  font-size: clamp(1.02rem, 2.4vw, 1.16rem);
  line-height: 1.85;
  color: var(--mist-100);
}

.page-about .about-stats {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 1px;
  margin: clamp(1.5rem, 3vw, 2rem) 0 0;
  padding: 0;
  list-style: none;
  background: var(--line);
  border: 1px solid var(--line);
}

.page-about .about-stats li {
  background: var(--ink-900);
  padding: 1rem 1.05rem;
}

.page-about .about-stats__num {
  display: block;
  font-family: var(--font-mono);
  font-size: clamp(1.45rem, 4vw, 2rem);
  line-height: 1;
  letter-spacing: 0.04em;
  color: var(--cyan-400);
}

.page-about .about-stats__label {
  display: block;
  margin-top: 0.55rem;
  font-size: 0.8rem;
  letter-spacing: 0.04em;
  color: var(--steel-500);
}

.page-about .about-lede__fig {
  margin: clamp(1.75rem, 4vw, 3rem) 0 0;
}

.page-about .about-lede__fig img {
  display: block;
  width: 100%;
  height: auto;
  aspect-ratio: 16 / 10;
  object-fit: cover;
  border: 1px solid var(--line);
}

/* ---------- 通用章节头 ---------- */
.page-about .about-head {
  margin: 0 0 clamp(1.5rem, 3vw, 2.25rem);
  max-width: 62ch;
}

.page-about .about-head .sec-title {
  margin: 0.6rem 0 0.8rem;
  font-family: var(--font-display);
  font-weight: 900;
  font-size: clamp(1.6rem, 4.4vw, 2.5rem);
  line-height: 1.15;
  letter-spacing: 0.04em;
  color: var(--mist-100);
}

.page-about .about-head .sec-lead {
  margin: 0;
  font-size: 0.98rem;
  line-height: 1.85;
  color: var(--mist-300);
}

/* ---------- 发展时间线 ---------- */
.page-about .about-era {
  padding: var(--about-pad) 0;
  background: var(--ink-900);
  border-top: 1px solid var(--line);
  border-bottom: 1px solid var(--line);
}

.page-about .about-era__fig {
  margin: 0 0 clamp(1.5rem, 3vw, 2.25rem);
}

.page-about .about-era__fig img {
  display: block;
  width: 100%;
  height: auto;
  aspect-ratio: 7 / 4;
  object-fit: cover;
  border: 1px solid var(--line);
  opacity: 0.92;
}

.page-about .about-filter {
  margin-bottom: clamp(1.25rem, 3vw, 1.75rem);
}

.page-about .about-filter .filter-status {
  width: 100%;
  margin: 0.35rem 0 0;
  font-family: var(--font-mono);
  font-size: 0.72rem;
  letter-spacing: 0.08em;
  color: var(--steel-500);
}

.page-about .about-era__scroll {
  overflow-x: auto;
  overflow-y: hidden;
  padding-bottom: 0.85rem;
  scroll-snap-type: x proximity;
  -webkit-overflow-scrolling: touch;
  scrollbar-color: var(--line) transparent;
}

.page-about .about-era__track {
  display: flex;
  gap: 1rem;
  margin: 0;
  padding: 0;
  list-style: none;
}

.page-about .about-era__item {
  flex: 0 0 min(82%, 320px);
  scroll-snap-align: start;
  padding: 1.1rem 1.1rem 1.25rem;
  background: var(--ink-800);
  border-top: 2px solid var(--line);
  transition: border-color 0.22s var(--ease), transform 0.22s var(--ease);
}

.page-about .about-era__item:hover,
.page-about .about-era__item:focus-within {
  border-top-color: var(--cyan-400);
  transform: translateY(-4px);
}

.page-about .about-era__year {
  display: inline-block;
  font-family: var(--font-mono);
  font-size: 1.5rem;
  font-weight: 600;
  letter-spacing: 0.06em;
  color: var(--cyan-400);
}

.page-about .about-era__title {
  margin: 0.5rem 0 0.6rem;
  font-family: var(--font-display);
  font-size: 1.02rem;
  font-weight: 700;
  line-height: 1.4;
  letter-spacing: 0.03em;
  color: var(--mist-100);
}

.page-about .about-era__item p {
  margin: 0 0 0.75rem;
  font-size: 0.88rem;
  line-height: 1.8;
  color: var(--mist-300);
}

.page-about .about-era__item .about-era__key {
  margin: 0;
  padding-top: 0.65rem;
  border-top: 1px solid var(--line);
  font-family: var(--font-mono);
  font-size: 0.7rem;
  line-height: 1.7;
  letter-spacing: 0.04em;
  color: var(--amber-300);
}

/* ---------- 资料整理 ---------- */
.page-about .about-method {
  padding: var(--about-pad) 0;
  scroll-margin-top: 5rem;
}

.page-about .about-method__grid {
  display: grid;
  gap: clamp(1.5rem, 4vw, 2.5rem);
}

.page-about .about-levels ol {
  display: grid;
  gap: 1px;
  margin: 0;
  padding: 0;
  list-style: none;
  background: var(--line);
  border: 1px solid var(--line);
}

.page-about .about-levels li {
  position: relative;
  padding: 1.15rem 1.2rem 1.25rem 1.4rem;
  background: var(--ink-950);
}

.page-about .about-levels li::before {
  content: "";
  position: absolute;
  left: 0;
  top: 0;
  bottom: 0;
  width: 2px;
  background: var(--cyan-400);
  opacity: 0.4;
}

.page-about .about-levels__k {
  display: block;
  font-family: var(--font-mono);
  font-size: 0.7rem;
  letter-spacing: 0.14em;
  color: var(--steel-500);
}

.page-about .about-levels strong {
  display: block;
  margin: 0.35rem 0 0.5rem;
  font-family: var(--font-display);
  font-weight: 700;
  font-size: 1.06rem;
  letter-spacing: 0.05em;
  color: var(--mist-100);
}

.page-about .about-levels p {
  margin: 0;
  font-size: 0.9rem;
  line-height: 1.8;
  color: var(--mist-300);
}

.page-about .about-version {
  padding: clamp(1.2rem, 3vw, 1.6rem);
  border: 1px solid var(--line);
  background: linear-gradient(160deg, var(--ink-800), var(--ink-950));
}

.page-about .about-version__label {
  margin: 0 0 1rem;
  font-family: var(--font-mono);
  font-size: 0.72rem;
  letter-spacing: 0.14em;
  color: var(--amber-300);
}

.page-about .about-version__code {
  display: flex;
  align-items: baseline;
  gap: 0.12rem;
  margin: 0 0 1.25rem;
  font-family: var(--font-mono);
  font-size: clamp(1.8rem, 5vw, 2.4rem);
  letter-spacing: 0.08em;
}

.page-about .about-version__code span {
  color: var(--cyan-400);
}

.page-about .about-version__code em {
  color: var(--steel-500);
  font-style: normal;
}

.page-about .about-version__list {
  display: grid;
  gap: 0.9rem;
  margin: 0;
  padding: 0;
  list-style: none;
}

.page-about .about-version__list li {
  padding-left: 0.9rem;
  border-left: 1px solid var(--line);
  font-size: 0.87rem;
  line-height: 1.8;
  color: var(--mist-300);
}

.page-about .about-version__list b {
  display: block;
  margin-bottom: 0.15rem;
  font-family: var(--font-display);
  font-size: 0.9rem;
  letter-spacing: 0.04em;
  color: var(--mist-100);
}

.page-about .about-version__note {
  margin: 1.2rem 0 0;
  padding-top: 0.9rem;
  border-top: 1px solid var(--line);
  font-size: 0.8rem;
  line-height: 1.75;
  color: var(--steel-500);
}

/* ---------- 团队分工 ---------- */
.page-about .about-team {
  padding: var(--about-pad) 0;
  background: var(--ink-900);
  border-top: 1px solid var(--line);
  border-bottom: 1px solid var(--line);
  scroll-margin-top: 5rem;
}

.page-about .about-team__grid {
  display: grid;
  gap: clamp(1rem, 3vw, 1.5rem);
  margin: 0;
  padding: 0;
  list-style: none;
}

.page-about .about-team__grid > li {
  padding: 1.15rem 1.1rem 1.3rem;
  background: var(--ink-950);
  border-top: 2px solid var(--line);
  transition: border-color 0.22s var(--ease);
}

.page-about .about-team__grid > li:hover {
  border-top-color: var(--amber-400);
}

.page-about .about-team__idx {
  display: block;
  font-family: var(--font-mono);
  font-size: 1.05rem;
  letter-spacing: 0.12em;
  color: var(--amber-400);
}

.page-about .about-team__grid h3 {
  margin: 0.55rem 0 0.55rem;
  font-family: var(--font-display);
  font-size: 1rem;
  font-weight: 700;
  letter-spacing: 0.05em;
  color: var(--mist-100);
}

.page-about .about-team__grid p {
  margin: 0 0 0.85rem;
  font-size: 0.87rem;
  line-height: 1.8;
  color: var(--mist-300);
}

.page-about .about-team__grid .about-team__rhythm {
  margin: 0;
  font-family: var(--font-mono);
  font-size: 0.7rem;
  letter-spacing: 0.08em;
  color: var(--cyan-400);
}

/* ---------- 协作生态 ---------- */
.page-about .about-eco {
  padding: var(--about-pad) 0;
  scroll-margin-top: 5rem;
}

.page-about .about-eco__grid {
  display: grid;
  gap: clamp(1.5rem, 4vw, 3rem);
}

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

.page-about .about-eco__fig img {
  display: block;
  width: 100%;
  height: auto;
  aspect-ratio: 14 / 9;
  object-fit: cover;
  border: 1px solid var(--line);
}

.page-about .about-eco__body .sec-title {
  margin: 0.6rem 0 0.8rem;
  font-family: var(--font-display);
  font-weight: 900;
  font-size: clamp(1.6rem, 4.4vw, 2.4rem);
  line-height: 1.15;
  letter-spacing: 0.04em;
  color: var(--mist-100);
}

.page-about .about-eco__body .sec-lead {
  margin: 0;
  font-size: 0.96rem;
  line-height: 1.85;
  color: var(--mist-300);
}

.page-about .about-eco__list {
  display: grid;
  gap: 0.9rem;
  margin: 1.35rem 0 0;
  padding: 0;
  list-style: none;
}

.page-about .about-eco__list li {
  padding-left: 1rem;
  border-left: 1px solid var(--amber-400);
  font-size: 0.9rem;
  line-height: 1.8;
  color: var(--mist-300);
}

.page-about .about-eco__list strong {
  font-family: var(--font-mono);
  font-size: 1rem;
  letter-spacing: 0.04em;
  color: var(--amber-300);
}

.page-about .about-eco__tail {
  margin: 1.25rem 0 0;
  font-size: 0.86rem;
  line-height: 1.8;
  color: var(--steel-500);
}

.page-about .about-eco__tail a {
  color: var(--cyan-400);
  text-decoration: none;
  border-bottom: 1px solid var(--line);
  transition: border-color 0.2s var(--ease);
}

.page-about .about-eco__tail a:hover,
.page-about .about-eco__tail a:focus-visible {
  border-bottom-color: var(--cyan-400);
}

/* ---------- 维护节奏与索引 ---------- */
.page-about .about-cadence {
  padding: var(--about-pad) 0;
  background: var(--ink-900);
  border-top: 1px solid var(--line);
  scroll-margin-top: 5rem;
}

.page-about .about-cadence__grid {
  display: grid;
  gap: clamp(1.5rem, 4vw, 2.5rem);
}

.page-about .about-rhythm {
  display: grid;
  gap: 1px;
  margin: 0;
  padding: 0;
  list-style: none;
  background: var(--line);
  border: 1px solid var(--line);
}

.page-about .about-rhythm li {
  display: grid;
  gap: 0.35rem;
  padding: 1rem 1.15rem;
  background: var(--ink-950);
}

.page-about .about-rhythm__k {
  font-family: var(--font-mono);
  font-size: 0.95rem;
  letter-spacing: 0.06em;
  color: var(--cyan-400);
}

.page-about .about-rhythm__v {
  font-size: 0.88rem;
  line-height: 1.8;
  color: var(--mist-300);
}

.page-about .about-toc {
  padding: clamp(1.1rem, 3vw, 1.5rem);
  background: var(--ink-800);
  border: 1px solid var(--line);
}

.page-about .about-toc__title {
  margin: 0 0 0.85rem;
  font-family: var(--font-mono);
  font-size: 0.72rem;
  letter-spacing: 0.14em;
  color: var(--amber-300);
}

.page-about .about-toc ul {
  display: grid;
  margin: 0;
  padding: 0;
  list-style: none;
}

.page-about .about-toc a {
  display: flex;
  gap: 0.9rem;
  align-items: baseline;
  padding: 0.65rem 0;
  border-bottom: 1px solid var(--line);
  font-size: 0.88rem;
  line-height: 1.6;
  color: var(--mist-300);
  text-decoration: none;
  transition: color 0.2s var(--ease), padding-left 0.2s var(--ease);
}

.page-about .about-toc a:hover,
.page-about .about-toc a:focus-visible {
  color: var(--cyan-400);
  padding-left: 0.35rem;
}

.page-about .about-toc__note {
  margin: 1rem 0 0;
  font-size: 0.8rem;
  line-height: 1.75;
  color: var(--steel-500);
}

/* ---------- 下一站 ---------- */
.page-about .about-next {
  padding: var(--about-pad) 0 calc(var(--about-pad) * 0.8);
}

.page-about .about-next h2 {
  margin: 0 0 1.25rem;
  font-family: var(--font-display);
  font-weight: 900;
  font-size: clamp(1.5rem, 4vw, 2.2rem);
  letter-spacing: 0.04em;
  color: var(--mist-100);
}

.page-about .about-next__links {
  display: flex;
  flex-wrap: wrap;
  gap: 0.75rem;
}

/* ---------- 响应式 ---------- */
@media (min-width: 620px) {
  .page-about .about-rhythm li {
    grid-template-columns: 8rem 1fr;
    align-items: baseline;
    gap: 1rem;
  }
}

@media (min-width: 720px) {
  .page-about .about-stats {
    grid-template-columns: repeat(4, minmax(0, 1fr));
  }

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

@media (min-width: 900px) {
  .page-about .about-lede__grid {
    grid-template-columns: 5fr 7fr;
    align-items: start;
  }

  .page-about .about-method__grid {
    grid-template-columns: 7fr 5fr;
    align-items: start;
  }

  .page-about .about-eco__grid {
    grid-template-columns: 6fr 6fr;
    align-items: center;
  }

  .page-about .about-cadence__grid {
    grid-template-columns: 7fr 5fr;
    align-items: start;
  }
}

@media (min-width: 1080px) {
  .page-about .about-team__grid {
    grid-template-columns: repeat(4, minmax(0, 1fr));
  }

  .page-about .about-team__grid > li:nth-child(even) {
    margin-top: 2.4rem;
  }

  .page-about .about-era__item {
    flex-basis: 300px;
  }
}

@media (prefers-reduced-motion: reduce) {
  .page-about .about-era__item,
  .page-about .about-team__grid > li,
  .page-about .about-toc a {
    transition: none;
  }

  .page-about .about-era__item:hover,
  .page-about .about-era__item:focus-within {
    transform: none;
  }
}