.page-about {
  --about-axis-w: 96px;
  --about-text: #26302b;
  --about-soft-text: #3d4741;
  --about-line: rgba(198, 161, 91, 0.55);
  --about-chapter-gap: clamp(1.8rem, 4.5vw, 2.8rem);
  background: var(--ink-green);
  color: var(--paper-white);
  padding-bottom: clamp(3rem, 8vw, 5rem);
  overflow-x: hidden;
}

.page-about .breadcrumb {
  padding-block: 1rem 0.4rem;
}

.page-about .breadcrumb__link {
  color: var(--gold-soft);
  text-decoration: none;
}

.page-about .breadcrumb__link:hover,
.page-about .breadcrumb__link:focus-visible {
  color: var(--paper-white);
  text-decoration: underline;
  text-underline-offset: 3px;
}

.page-about .breadcrumb__sep,
.page-about .breadcrumb__current {
  color: var(--grey-green);
}

/* ---------- 首屏 ---------- */
.about-hero {
  padding-top: clamp(1rem, 3vw, 1.8rem);
}

.about-hero__inner {
  display: grid;
  grid-template-columns: 1fr;
  gap: clamp(1.4rem, 4vw, 2.2rem);
}

.about-hero__title {
  font-family: var(--font-serif);
  font-size: clamp(1.85rem, 6vw, 3.6rem);
  font-weight: 800;
  line-height: 1.16;
  letter-spacing: 0.01em;
  margin: 0.55rem 0 0;
  color: var(--paper-white);
}

.about-hero__title em {
  font-style: normal;
  color: var(--gold);
  border-bottom: 3px solid var(--cinnabar);
  padding-bottom: 0.06em;
}

.about-hero__intro {
  max-width: 56ch;
  margin: 1rem 0 0;
  font-size: var(--step-body);
  line-height: 1.85;
  color: var(--muted);
}

.about-hero__actions {
  display: flex;
  flex-wrap: wrap;
  gap: 0.7rem;
  margin-top: 1.4rem;
}

.about-hero__figure {
  margin: 0;
  border-color: var(--gold);
  box-shadow: 6px 6px 0 var(--ink-green-deep);
}

.about-hero__figure .media-frame__caption {
  color: var(--muted);
}

/* ---------- 关键数字条 ---------- */
.about-stats {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 2px;
  background: var(--gold);
  border: 2px solid var(--gold);
  box-shadow: 6px 6px 0 var(--ink-green-deep);
}

.about-stats__item {
  display: flex;
  flex-direction: column;
  gap: 0.2rem;
  padding: 0.9rem 1rem;
  background: var(--ink-green-deep);
}

.about-stats__num {
  font-family: var(--font-mono);
  font-size: clamp(1.4rem, 3.4vw, 2rem);
  font-weight: 500;
  letter-spacing: 0.04em;
  color: var(--gold);
  line-height: 1.1;
}

.about-stats__label {
  font-size: var(--step-mini);
  letter-spacing: 0.1em;
  color: var(--grey-green);
}

/* ---------- 卷宗目录 ---------- */
.about-toc {
  margin-top: clamp(2rem, 5vw, 3rem);
  padding: clamp(1rem, 2.6vw, 1.5rem);
  background: var(--paper-yellow);
  color: var(--ink-black);
  border: var(--border);
  box-shadow: var(--shadow-hard);
}

.about-toc__title {
  margin: 0;
  font-size: var(--step-mini);
  letter-spacing: 0.22em;
  text-transform: uppercase;
  color: var(--copper);
  border-bottom: 2px solid var(--copper);
  padding-bottom: 0.6rem;
}

.about-toc__list {
  list-style: none;
  margin: 0.7rem 0 0;
  padding: 0;
  display: grid;
  grid-template-columns: 1fr;
  gap: 0.1rem;
}

.about-toc__link {
  display: flex;
  align-items: baseline;
  gap: 0.7rem;
  padding: 0.55rem 0.45rem;
  color: var(--ink-black);
  text-decoration: none;
  font-size: 0.94rem;
  line-height: 1.5;
  border-bottom: 1px dashed rgba(140, 106, 63, 0.45);
  transition: background 0.22s var(--ease), color 0.22s var(--ease);
}

.about-toc__num {
  flex: none;
  font-size: 0.76rem;
  letter-spacing: 0.12em;
  color: var(--cinnabar);
  transition: color 0.22s var(--ease);
}

.about-toc__link:hover,
.about-toc__link:focus-visible {
  background: var(--ink-green);
  color: var(--paper-white);
}

.about-toc__link:hover .about-toc__num,
.about-toc__link:focus-visible .about-toc__num {
  color: var(--gold);
}

/* ---------- 章节骨架 ---------- */
.about-layout {
  display: grid;
  grid-template-columns: 1fr;
  gap: var(--about-chapter-gap);
  margin-top: clamp(2.2rem, 6vw, 3.4rem);
}

.about-chapter {
  display: grid;
  grid-template-columns: 1fr;
  gap: 0.7rem;
  scroll-margin-top: 5rem;
}

.about-chapter__axis {
  position: relative;
  display: flex;
  align-items: center;
  gap: 0.6rem;
}

.about-axis__year {
  font-size: 0.9rem;
  letter-spacing: 0.12em;
  color: var(--gold);
  flex: none;
}

.about-axis__dot {
  position: relative;
  flex: none;
  width: 20px;
  height: 20px;
  border-radius: 50%;
  border: 2px solid var(--gold);
  background: var(--ink-green);
  display: grid;
  place-items: center;
  z-index: 1;
}

.about-axis__dot::after {
  content: "";
  width: 7px;
  height: 7px;
  border-radius: 50%;
  background: var(--cinnabar);
}

.about-axis__label {
  font-size: 0.7rem;
  letter-spacing: 0.18em;
  color: var(--grey-green);
  flex: none;
}

.about-chapter__body {
  padding: clamp(1.15rem, 3vw, 2rem);
  background: var(--paper-white);
  color: var(--about-text);
  border: var(--border);
  box-shadow: var(--shadow-hard);
}

.about-chapter--yellow .about-chapter__body {
  background: var(--paper-yellow);
}

.about-chapter__title {
  position: relative;
  margin: 0;
  padding-top: 1rem;
  font-family: var(--font-serif);
  font-size: var(--step-h2);
  font-weight: 800;
  line-height: 1.22;
  color: var(--ink-black);
}

.about-chapter__title::before {
  content: "";
  position: absolute;
  top: 0;
  left: 0;
  width: 48px;
  height: 4px;
  background: var(--cinnabar);
}

.about-chapter__body p {
  margin: 0.85rem 0 0;
  font-size: var(--step-body);
  line-height: 1.85;
  color: var(--about-soft-text);
}

.about-num {
  font-family: var(--font-mono);
  font-size: 1.18em;
  font-weight: 500;
  letter-spacing: 0.03em;
  color: var(--ink-green);
  border-bottom: 2px solid var(--cinnabar);
  padding-bottom: 0.04em;
}

.about-subhead {
  margin: 1.6rem 0 0;
  font-family: var(--font-serif);
  font-size: var(--step-h3);
  font-weight: 700;
  color: var(--ink-black);
  padding-left: 0.75rem;
  border-left: 4px solid var(--gold);
}

/* ---------- 要点列表 ---------- */
.about-points {
  list-style: none;
  margin: 1rem 0 0;
  padding: 0;
  display: grid;
  gap: 0.55rem;
}

.about-points li {
  position: relative;
  padding-left: 1.15rem;
  font-size: 0.95rem;
  line-height: 1.8;
  color: var(--about-soft-text);
}

.about-points li::before {
  content: "";
  position: absolute;
  left: 0;
  top: 0.72em;
  width: 8px;
  height: 8px;
  background: var(--cinnabar);
  transform: rotate(45deg);
}

.about-points strong {
  color: var(--ink-green);
  font-weight: 700;
}

/* ---------- 编号示例块 ---------- */
.about-code {
  margin-top: 1.3rem;
  padding: clamp(0.9rem, 2.4vw, 1.25rem);
  background: var(--ink-green-deep);
  color: var(--paper-white);
  border: 2px solid var(--gold);
  box-shadow: 5px 5px 0 rgba(7, 26, 21, 0.6);
}

.about-code__cap {
  margin: 0;
  font-size: 0.72rem;
  letter-spacing: 0.22em;
  color: var(--gold-soft);
}

.about-code__value {
  margin: 0.5rem 0 0;
  font-family: var(--font-mono);
  font-size: clamp(1.05rem, 3vw, 1.5rem);
  letter-spacing: 0.08em;
  color: var(--gold);
  word-break: break-word;
}

.about-code__legend {
  list-style: none;
  margin: 0.7rem 0 0;
  padding: 0;
  display: grid;
  gap: 0.35rem;
  font-size: 0.84rem;
  line-height: 1.7;
  color: var(--muted);
}

.about-code__legend .mono {
  display: inline-block;
  min-width: 5.4rem;
  color: var(--paper-white);
}

/* ---------- 图片 ---------- */
.about-figure {
  margin: 1.4rem 0 0;
  border-color: var(--copper);
}

.about-figure--4x3 {
  aspect-ratio: 4 / 3;
}

/* ---------- 筛选条 ---------- */
.about-filter {
  margin-top: 1.2rem;
  padding: 0.7rem;
  background: var(--ink-green-deep);
  border: 2px solid var(--ink-green-deep);
}

/* ---------- 六类资料 ---------- */
.about-docs {
  list-style: none;
  margin: 1.2rem 0 0;
  padding: 0;
  display: grid;
  grid-template-columns: 1fr;
  gap: 0.75rem;
}

.about-docs__item {
  padding: 0.85rem 1rem;
  background: rgba(246, 241, 229, 0.62);
  border: 1px solid var(--copper);
  border-left: 4px solid var(--cinnabar);
}

.about-docs__item[hidden] {
  display: none !important;
}

.about-docs__name {
  margin: 0;
  font-family: var(--font-serif);
  font-size: 1.02rem;
  font-weight: 700;
  color: var(--ink-black);
}

.about-docs__desc {
  margin: 0.35rem 0 0;
  font-size: 0.87rem;
  line-height: 1.72;
  color: var(--about-soft-text);
}

/* ---------- 三种找法 ---------- */
.about-methods {
  display: grid;
  grid-template-columns: 1fr;
  gap: 0.7rem;
  margin-top: 0.9rem;
}

.about-methods__item {
  padding: 0.8rem 0.9rem;
  background: var(--paper-white);
  border: 1px dashed var(--copper);
}

.about-chapter--yellow .about-methods__item {
  background: rgba(246, 241, 229, 0.7);
}

.about-methods__tag {
  display: inline-block;
  font-size: 0.72rem;
  letter-spacing: 0.16em;
  color: var(--paper-white);
  background: var(--ink-green);
  padding: 0.18rem 0.5rem;
}

.about-methods__item p {
  margin: 0.55rem 0 0;
  font-size: 0.88rem;
  line-height: 1.72;
}

/* ---------- 归档流程 ---------- */
.about-flow {
  list-style: none;
  margin: 1.2rem 0 0;
  padding: 0;
}

.about-flow__step {
  display: grid;
  grid-template-columns: 2.2rem minmax(0, 1fr);
  gap: 0.75rem;
  padding: 0.9rem 0;
  border-bottom: 1px dashed rgba(140, 106, 63, 0.55);
}

.about-flow__step:last-child {
  border-bottom: none;
}

.about-flow__idx {
  display: grid;
  place-items: center;
  width: 2.2rem;
  height: 2.2rem;
  font-size: 0.82rem;
  letter-spacing: 0.06em;
  color: var(--ink-green);
  background: rgba(198, 161, 91, 0.28);
  border: 2px solid var(--copper);
}

.about-flow__text h3 {
  margin: 0;
  font-family: var(--font-serif);
  font-size: 1.02rem;
  font-weight: 700;
  color: var(--ink-black);
  line-height: 1.4;
}

.about-flow__text p {
  margin: 0.3rem 0 0;
  font-size: 0.88rem;
  line-height: 1.72;
}

/* ---------- 折叠 ---------- */
.about-fold {
  margin-top: 1.3rem;
  border: 2px solid var(--ink-green);
  background: rgba(246, 241, 229, 0.72);
}

.about-chapter--yellow .about-fold {
  background: var(--paper-white);
}

.about-fold__summary {
  cursor: pointer;
  padding: 0.8rem 1rem;
  font-weight: 700;
  font-size: 0.94rem;
  color: var(--ink-green);
  list-style: none;
  display: flex;
  align-items: center;
  gap: 0.6rem;
}

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

.about-fold__summary::before {
  content: "+";
  font-family: var(--font-mono);
  font-size: 1.05rem;
  color: var(--cinnabar);
  line-height: 1;
}

.about-fold[open] .about-fold__summary::before {
  content: "−";
}

.about-fold__summary:focus-visible {
  outline: 3px solid var(--cinnabar);
  outline-offset: -3px;
}

.about-fold__body {
  padding: 0 1rem 0.9rem;
}

.about-fold__body p {
  margin: 0.5rem 0 0;
  font-size: 0.88rem;
  line-height: 1.78;
}

/* ---------- 服务场景 ---------- */
.about-scenes {
  list-style: none;
  margin: 0.9rem 0 0;
  padding: 0;
  display: grid;
  gap: 0.6rem;
}

.about-scenes li {
  display: grid;
  grid-template-columns: 1.4rem minmax(0, 1fr);
  gap: 0.5rem;
  align-items: start;
  font-size: 0.9rem;
  line-height: 1.75;
  color: var(--about-soft-text);
  padding: 0.6rem 0.8rem;
  background: rgba(246, 241, 229, 0.65);
  border-left: 3px solid var(--gold);
}

.about-scenes__icon {
  color: var(--cinnabar);
  font-size: 0.7rem;
  line-height: 1.9;
}

/* ---------- 延伸入口 ---------- */
.about-next {
  margin-top: clamp(2.4rem, 6vw, 3.6rem);
}

.about-next__title {
  margin: 0 0 1rem;
  font-family: var(--font-serif);
  font-size: var(--step-h2);
  font-weight: 800;
  color: var(--paper-white);
  position: relative;
  padding-top: 0.9rem;
}

.about-next__title::before {
  content: "";
  position: absolute;
  top: 0;
  left: 0;
  width: 48px;
  height: 4px;
  background: var(--cinnabar);
}

.about-next__grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: 0.8rem;
}

.about-next__card {
  display: flex;
  flex-direction: column;
  gap: 0.35rem;
  padding: 1rem 1.1rem;
  background: var(--ink-green-deep);
  color: var(--paper-white);
  text-decoration: none;
  border: 2px solid var(--gold);
  box-shadow: 5px 5px 0 rgba(7, 26, 21, 0.75);
  transition: transform 0.22s var(--ease), box-shadow 0.22s var(--ease), border-color 0.22s var(--ease);
}

.about-next__card:hover,
.about-next__card:focus-visible {
  transform: translate(-2px, -2px);
  box-shadow: 7px 7px 0 var(--cinnabar);
  border-color: var(--gold-soft);
}

.about-next__kicker {
  font-size: 0.7rem;
  letter-spacing: 0.2em;
  color: var(--gold);
}

.about-next__name {
  font-family: var(--font-serif);
  font-size: 1.12rem;
  font-weight: 700;
  color: var(--paper-white);
}

.about-next__desc {
  font-size: 0.85rem;
  line-height: 1.7;
  color: var(--muted);
}

/* ---------- 响应式 ---------- */
@media (min-width: 560px) {
  .about-stats {
    grid-template-columns: repeat(4, minmax(0, 1fr));
  }

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

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

@media (min-width: 720px) {
  .about-toc__list {
    grid-template-columns: repeat(2, minmax(0, 1fr));
    column-gap: 1.2rem;
  }

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

@media (min-width: 820px) {
  .about-chapter {
    grid-template-columns: var(--about-axis-w) minmax(0, 1fr);
    gap: clamp(1rem, 2.4vw, 1.8rem);
    align-items: stretch;
  }

  .about-chapter__axis {
    flex-direction: column;
    align-items: center;
    justify-content: flex-start;
    gap: 0.45rem;
    padding-top: 0.7rem;
    text-align: center;
  }

  .about-chapter__axis::before {
    content: "";
    position: absolute;
    left: 50%;
    top: 0;
    bottom: 0;
    width: 2px;
    transform: translateX(-50%);
    background: linear-gradient(180deg, rgba(198, 161, 91, 0.85), var(--about-line));
  }

  .about-chapter:first-of-type .about-chapter__axis::before {
    top: 2.4rem;
  }

  .about-chapter:last-of-type .about-chapter__axis::before {
    bottom: 2.4rem;
  }

  .about-axis__label {
    letter-spacing: 0.14em;
  }

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

@media (min-width: 1024px) {
  .about-hero__inner {
    grid-template-columns: minmax(0, 1.15fr) minmax(0, 0.85fr);
    align-items: start;
  }

  .about-hero__lead {
    grid-column: 1;
    grid-row: 1;
  }

  .about-hero__figure {
    grid-column: 2;
    grid-row: 1 / span 2;
    align-self: stretch;
    aspect-ratio: 4 / 5;
  }

  .about-stats {
    grid-column: 1;
    grid-row: 2;
  }
}

@media (prefers-reduced-motion: reduce) {
  .about-toc__link,
  .about-next__card {
    transition: none;
  }

  .about-next__card:hover,
  .about-next__card:focus-visible {
    transform: none;
  }
}
<<<END>>>