.page-about {
  --about-hair: rgba(227, 234, 240, 0.13);
  --about-hair-strong: rgba(227, 234, 240, 0.26);
  --about-dim: rgba(227, 234, 240, 0.74);
  --about-dim-soft: rgba(227, 234, 240, 0.58);
  background: var(--pitch-900);
  color: var(--chalk-50);
  overflow-x: hidden;
  padding-bottom: 88px;
}

.page-about a {
  color: var(--lemon-400);
}

/* ---------- 首屏 ---------- */
.page-about .about-hero {
  padding: 28px 0 56px;
  border-bottom: 1px solid var(--about-hair);
  background:
    radial-gradient(120% 90% at 88% 0%, rgba(203, 249, 78, 0.09), transparent 58%),
    linear-gradient(180deg, var(--pitch-950) 0%, var(--pitch-900) 100%);
}

.page-about .about-hero .breadcrumb {
  margin-bottom: 32px;
}

.page-about .about-hero__grid {
  display: grid;
  gap: 34px;
}

.page-about .about-hero__intro {
  display: grid;
  gap: 16px;
  max-width: 68ch;
}

.page-about .about-hero h1 {
  font-size: clamp(1.85rem, 6vw, 3rem);
  font-weight: 900;
  letter-spacing: -0.035em;
  line-height: 1.12;
  margin: 0;
}

.page-about .about-hero .lede {
  margin: 0;
  font-size: 1rem;
  line-height: 1.8;
  color: var(--about-dim);
}

.page-about .about-board {
  background: var(--slate-800);
  border: 1px solid var(--about-hair-strong);
  border-radius: var(--radius-md) var(--radius-md) var(--radius-md) 8px;
  padding: 24px 22px 20px;
  display: grid;
  gap: 2px;
}

.page-about .about-board__label {
  margin: 0;
  font-family: var(--font-mono);
  font-size: 0.75rem;
  letter-spacing: 0.12em;
  color: var(--mist-400);
}

.page-about .about-board__num {
  margin: 0;
  font-family: var(--font-mono);
  font-weight: 700;
  font-size: clamp(2.75rem, 12vw, 4.25rem);
  line-height: 1;
  letter-spacing: -0.03em;
  color: var(--lemon-400);
  font-variant-numeric: tabular-nums;
}

.page-about .about-board__unit {
  margin: 0 0 14px;
  font-size: 0.9375rem;
  color: var(--about-dim);
}

.page-about .about-board__list {
  list-style: none;
  margin: 0;
  padding: 14px 0 0;
  border-top: 1px solid var(--about-hair);
  display: grid;
  gap: 8px;
}

.page-about .about-board__list li {
  display: flex;
  justify-content: space-between;
  align-items: baseline;
  gap: 12px;
  font-size: 0.875rem;
  color: var(--mist-400);
}

.page-about .about-board__list strong {
  font-family: var(--font-mono);
  font-weight: 700;
  color: var(--chalk-50);
  font-variant-numeric: tabular-nums;
}

/* ---------- 章节布局 ---------- */
.page-about .about-layout {
  display: grid;
  gap: 36px;
  padding-top: 44px;
}

.page-about .about-toc {
  border-left: 2px solid var(--lemon-400);
  padding: 2px 0 2px 16px;
}

.page-about .about-toc__title {
  margin: 0 0 12px;
  font-family: var(--font-mono);
  font-size: 0.75rem;
  letter-spacing: 0.12em;
  color: var(--mist-400);
  text-transform: uppercase;
}

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

.page-about .about-toc__list a {
  display: flex;
  align-items: baseline;
  gap: 10px;
  font-size: 0.9375rem;
  font-weight: 500;
  color: var(--chalk-50);
  text-decoration: none;
  border-bottom: 1px solid transparent;
  padding-bottom: 2px;
  transition: color 200ms var(--ease), border-color 200ms var(--ease);
}

.page-about .about-toc__list a:hover,
.page-about .about-toc__list a:focus-visible {
  color: var(--lemon-400);
  border-color: var(--line-lemon);
}

.page-about .about-toc__num {
  font-family: var(--font-mono);
  font-size: 0.75rem;
  letter-spacing: 0.08em;
  color: var(--mist-400);
}

.page-about .about-body {
  display: grid;
  gap: 64px;
  min-width: 0;
}

.page-about .about-section {
  scroll-margin-top: calc(var(--header-h) + 24px);
  min-width: 0;
}

.page-about .section-head {
  display: grid;
  gap: 10px;
  margin-bottom: 26px;
  max-width: 66ch;
}

.page-about .section-title {
  font-size: clamp(1.35rem, 4vw, 1.75rem);
  font-weight: 900;
  letter-spacing: -0.03em;
  line-height: 1.25;
  margin: 0;
}

.page-about .section-head__desc {
  margin: 0;
  font-size: 0.9375rem;
  line-height: 1.8;
  color: var(--about-dim);
}

.page-about .about-section .note {
  margin-top: 22px;
  max-width: 74ch;
}

/* ---------- 01 记录边界 ---------- */
.page-about .scope-split {
  display: grid;
  gap: 16px;
}

.page-about .scope-col {
  border-radius: var(--radius-md);
  padding: 24px 20px 20px;
  border: 1px solid var(--about-hair);
}

.page-about .scope-col--in {
  background: var(--slate-800);
  border-left: 3px solid var(--lemon-400);
  border-radius: 8px var(--radius-md) var(--radius-md) var(--radius-md);
}

.page-about .scope-col--out {
  background: var(--slate-100);
  color: var(--pitch-900);
  border-top: 4px solid var(--card-400);
  border-radius: var(--radius-md) var(--radius-md) 8px var(--radius-md);
}

.page-about .scope-col__title {
  margin: 0 0 16px;
  font-size: 1.125rem;
  font-weight: 900;
  letter-spacing: -0.02em;
  padding-bottom: 12px;
  border-bottom: 1px solid var(--about-hair);
}

.page-about .scope-col--out .scope-col__title {
  border-bottom-color: rgba(11, 36, 29, 0.16);
}

.page-about .scope-list {
  margin: 0;
  display: grid;
  gap: 14px;
}

.page-about .scope-row {
  display: grid;
  gap: 4px;
}

.page-about .scope-row dt {
  font-family: var(--font-mono);
  font-size: 0.75rem;
  letter-spacing: 0.08em;
  color: var(--mist-400);
}

.page-about .scope-col--out .scope-row dt {
  color: rgba(11, 36, 29, 0.6);
}

.page-about .scope-row dd {
  margin: 0;
  font-size: 0.9375rem;
  line-height: 1.7;
}

.page-about .scope-col--in .scope-row dd {
  color: var(--about-dim);
}

/* ---------- 图片 ---------- */
.page-about .about-figure {
  margin: 0 0 30px;
}

.page-about .about-figure--texture {
  margin: 34px 0 0;
  border-radius: var(--radius-md);
  overflow: hidden;
}

.page-about .about-figure--tail {
  margin: 34px 0 0;
}

.page-about .about-figure img {
  max-width: 100%;
  height: auto;
  display: block;
  object-fit: cover;
  width: 100%;
}

.page-about .about-figure .figure-frame__media {
  border-radius: var(--radius-md);
  overflow: hidden;
}

.page-about .about-figure--texture .figure-frame__media {
  border-radius: 0;
}

/* ---------- 02 流程 ---------- */
.page-about .flow {
  list-style: none;
  margin: 0;
  padding: 0;
}

.page-about .flow-step {
  display: grid;
  grid-template-columns: 2.25rem minmax(0, 1fr);
  gap: 14px;
  padding: 22px 0;
  border-top: 1px solid var(--about-hair);
}

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

.page-about .flow-step__num {
  margin: 0;
  font-family: var(--font-mono);
  font-size: 0.8125rem;
  font-weight: 500;
  letter-spacing: 0.08em;
  color: var(--lemon-400);
  padding-top: 5px;
}

.page-about .flow-step__body {
  display: grid;
  gap: 8px;
  min-width: 0;
}

.page-about .flow-step__title {
  margin: 0;
  font-size: 1.0625rem;
  font-weight: 900;
  letter-spacing: -0.02em;
}

.page-about .flow-step__body p {
  margin: 0;
  font-size: 0.9375rem;
  line-height: 1.75;
  color: var(--about-dim);
}

.page-about .flow-step__body .note {
  margin: 2px 0 0;
  color: var(--mist-400);
}

/* ---------- 03 团队 ---------- */
.page-about .crew {
  list-style: none;
  margin: 0;
  padding: 0;
  display: grid;
  gap: 14px;
}

.page-about .crew-card {
  background: var(--slate-800);
  border: 1px solid var(--about-hair);
  border-radius: var(--radius-md) var(--radius-md) var(--radius-md) 6px;
  padding: 20px 18px 18px;
  display: grid;
  gap: 8px;
  align-content: start;
  transition: border-color 220ms var(--ease);
}

.page-about .crew-card:hover {
  border-color: var(--line-lemon);
}

.page-about .crew-card__num {
  margin: 0;
  font-family: var(--font-mono);
  font-size: 2rem;
  font-weight: 700;
  line-height: 1;
  letter-spacing: -0.03em;
  color: var(--lemon-400);
  font-variant-numeric: tabular-nums;
}

.page-about .crew-card__title {
  margin: 0;
  font-size: 1rem;
  font-weight: 900;
  letter-spacing: -0.02em;
}

.page-about .crew-card__desc {
  margin: 0;
  font-size: 0.875rem;
  line-height: 1.75;
  color: var(--about-dim);
}

.page-about .crew-card__handoff {
  margin: 6px 0 0;
  padding-top: 10px;
  border-top: 1px dashed var(--about-hair-strong);
  font-family: var(--font-mono);
  font-size: 0.75rem;
  letter-spacing: 0.04em;
  color: var(--teal-400);
}

/* ---------- 04 版本演进 ---------- */
.page-about .version-band {
  margin-top: 4px;
  padding: 22px 0 6px;
  border-top: 1px solid var(--about-hair);
  border-bottom: 1px solid var(--about-hair);
}

.page-about .version-list {
  list-style: none;
  margin: 0;
  padding: 0;
  display: grid;
  gap: 16px;
}

.page-about .version-item {
  display: flex;
  gap: 12px;
  align-items: flex-start;
  min-width: 0;
}

.page-about .version-item__dot {
  flex: 0 0 auto;
  width: 14px;
  height: 14px;
  margin-top: 14px;
  border-radius: 50%;
  border: 2px solid var(--lemon-400);
  background: var(--pitch-900);
}

.page-about .version-node {
  flex: 1 1 auto;
  min-width: 0;
}

.page-about .version-trigger {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 10px;
  width: 100%;
  padding: 12px 14px;
  border: 1px solid var(--about-hair-strong);
  border-radius: var(--radius-sm) var(--radius-sm) var(--radius-sm) 4px;
  background: var(--slate-800);
  color: var(--chalk-50);
  font: inherit;
  text-align: left;
  cursor: pointer;
  transition: border-color 200ms var(--ease), background-color 200ms var(--ease);
}

.page-about .version-trigger:hover,
.page-about .version-trigger:focus-visible {
  border-color: var(--lemon-400);
  background: rgba(203, 249, 78, 0.06);
}

.page-about .version-trigger__label {
  display: grid;
  gap: 3px;
  min-width: 0;
}

.page-about .version-code {
  font-family: var(--font-mono);
  font-size: 0.75rem;
  font-weight: 700;
  letter-spacing: 0.1em;
  color: var(--lemon-400);
}

.page-about .version-name {
  font-size: 0.9375rem;
  font-weight: 700;
  letter-spacing: -0.015em;
  line-height: 1.4;
}

.page-about .version-panel {
  padding: 12px 2px 4px;
  display: grid;
  gap: 8px;
}

.page-about .version-panel p {
  margin: 0;
  font-size: 0.875rem;
  line-height: 1.75;
  color: var(--about-dim);
}

.page-about .version-panel .note {
  margin: 0;
}

/* ---------- 05 复核与勘误 ---------- */
.page-about .about-review {
  background: var(--pitch-950);
  border: 1px solid var(--about-hair-strong);
  border-radius: var(--radius-md);
  padding: 26px 20px 22px;
}

.page-about .review-list {
  list-style: none;
  margin: 0;
  padding: 0;
  display: grid;
  gap: 22px;
}

.page-about .review-item {
  display: grid;
  gap: 8px;
  align-content: start;
}

.page-about .review-item__tag {
  justify-self: start;
}

.page-about .review-item__title {
  margin: 0;
  font-size: 1.0625rem;
  font-weight: 900;
  letter-spacing: -0.02em;
}

.page-about .review-item p {
  margin: 0;
  font-size: 0.9375rem;
  line-height: 1.8;
  color: var(--about-dim);
}

.page-about .review-actions {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
  margin-top: 26px;
  padding-top: 22px;
  border-top: 1px solid var(--about-hair);
}

/* ---------- 媒体查询 ---------- */
@media (min-width: 700px) {
  .page-about .about-hero {
    padding: 36px 0 68px;
  }

  .page-about .scope-split {
    grid-template-columns: repeat(2, minmax(0, 1fr));
    gap: 20px;
  }

  .page-about .scope-col {
    padding: 28px 24px 24px;
  }

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

  .page-about .about-review {
    padding: 32px 28px 26px;
  }
}

@media (min-width: 900px) {
  .page-about .about-hero__grid {
    grid-template-columns: minmax(0, 7fr) minmax(0, 4fr);
    gap: 52px;
    align-items: end;
  }

  .page-about .about-toc {
    position: sticky;
    top: calc(var(--header-h) + 28px);
    align-self: start;
  }

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

  .page-about .version-band {
    padding: 30px 0 26px;
  }

  .page-about .version-list {
    position: relative;
    grid-template-columns: repeat(5, minmax(0, 1fr));
    gap: 18px;
    padding-top: 26px;
  }

  .page-about .version-list::before {
    content: "";
    position: absolute;
    left: 7px;
    right: 7px;
    top: 7px;
    height: 1px;
    background: var(--about-hair-strong);
  }

  .page-about .version-item {
    display: block;
    position: relative;
  }

  .page-about .version-item__dot {
    position: absolute;
    top: -26px;
    left: 0;
    margin: 0;
    z-index: 1;
  }

  .page-about .review-list {
    grid-template-columns: repeat(3, minmax(0, 1fr));
    gap: 26px;
  }

  .page-about .review-item {
    padding-right: 12px;
    border-right: 1px solid var(--about-hair);
  }

  .page-about .review-item:last-child {
    border-right: none;
    padding-right: 0;
  }
}

@media (min-width: 1080px) {
  .page-about .about-layout {
    grid-template-columns: 236px minmax(0, 1fr);
    gap: 60px;
    padding-top: 56px;
  }

  .page-about .about-body {
    gap: 84px;
  }

  .page-about .flow-step {
    grid-template-columns: 3.25rem minmax(0, 1fr);
    gap: 20px;
  }
}

@media (prefers-reduced-motion: reduce) {
  .page-about .crew-card,
  .page-about .version-trigger,
  .page-about .about-toc__list a {
    transition: none;
  }
}