.page-about {
  --about-line: 1px solid var(--moss);
  --about-body-w: 34em;
  background: var(--ink);
  color: var(--paper);
  font-family: var(--font-body);
  overflow-x: hidden;
}

.page-about .about-shell {
  width: 100%;
  max-width: var(--max-w);
  margin-inline: auto;
  padding-inline: var(--edge);
}

.page-about .about-shell--top {
  padding-block: clamp(20px, 4vw, 40px) clamp(28px, 5vw, 56px);
}

.page-about .breadcrumb ol {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
  margin: 0 0 clamp(24px, 5vw, 48px);
  padding: 0;
  list-style: none;
  font-size: 13px;
  color: var(--muted);
}

.page-about .breadcrumb li + li::before {
  content: "/";
  margin-right: 8px;
  color: var(--moss);
}

.page-about .breadcrumb a {
  color: var(--muted);
  text-decoration: none;
  transition: color var(--ease);
}

.page-about .breadcrumb a:hover {
  color: var(--cyan);
}

.page-about .eyebrow {
  margin: 0 0 16px;
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.16em;
  color: var(--cyan);
  text-transform: uppercase;
}

/* 首屏封面 */
.page-about .about-hero {
  position: relative;
  padding-block: clamp(12px, 3vw, 28px) clamp(32px, 6vw, 64px);
  background-image:
    linear-gradient(to right, rgba(27, 74, 58, 0.55) 1px, transparent 1px),
    linear-gradient(to bottom, rgba(27, 74, 58, 0.55) 1px, transparent 1px);
  background-size: 88px 88px;
  background-position: -1px -1px;
}

.page-about .about-hero__title {
  margin: 0;
  font-family: var(--font-display);
  font-weight: 900;
  font-size: clamp(48px, 13vw, 132px);
  line-height: 0.86;
  letter-spacing: -0.045em;
  color: var(--white);
}

.page-about .about-hero__title-sub {
  display: block;
  margin-top: 10px;
  font-size: clamp(20px, 4.4vw, 40px);
  letter-spacing: 0.06em;
  color: var(--cyan);
  font-weight: 700;
}

.page-about .about-hero__body {
  max-width: 46em;
  margin-top: clamp(24px, 4vw, 40px);
  padding-left: clamp(0px, 2vw, 24px);
  border-left: 2px solid var(--moss);
}

.page-about .about-hero__lede {
  margin: 0;
  font-size: clamp(16px, 2.1vw, 19px);
  line-height: 1.8;
  color: var(--paper);
}

.page-about .about-hero__meta {
  margin: 18px 0 0;
  font-size: 13px;
  letter-spacing: 0.04em;
  color: var(--orange);
}

/* 章节索引 */
.page-about .about-index {
  margin-top: clamp(32px, 6vw, 64px);
}

.page-about .about-index ol {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 0;
  margin: 0;
  padding: 0;
  list-style: none;
  border-top: var(--about-line);
}

.page-about .about-index li {
  border-bottom: var(--about-line);
}

.page-about .about-index a {
  display: flex;
  align-items: baseline;
  gap: 14px;
  padding: 13px 2px;
  color: var(--paper);
  text-decoration: none;
  font-size: 15px;
  transition: color var(--ease), transform var(--ease);
}

.page-about .about-index a .mono {
  font-size: 12px;
  color: var(--muted);
  letter-spacing: 0.08em;
}

.page-about .about-index a:hover,
.page-about .about-index a:focus-visible {
  color: var(--cyan);
  transform: translateX(3px);
}

.page-about .about-index a:hover .mono {
  color: var(--cyan);
}

/* 章节骨架 */
.page-about .about-chapter {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: clamp(18px, 3vw, 32px);
  padding-block: clamp(36px, 7vw, 88px);
  border-top: var(--about-line);
}

.page-about .about-chapter:target .about-chapter__num {
  color: var(--cyan);
}

.page-about .about-chapter__rail {
  display: flex;
  align-items: baseline;
  gap: 16px;
}

.page-about .about-chapter__rail--row {
  flex-wrap: wrap;
  align-items: flex-end;
  gap: 8px 20px;
}

.page-about .about-chapter__num {
  font-size: clamp(40px, 7vw, 88px);
  line-height: 0.9;
  font-weight: 700;
  letter-spacing: -0.04em;
  color: var(--moss);
  transition: color var(--ease);
}

.page-about .about-chapter__title {
  margin: 0;
  font-family: var(--font-display);
  font-weight: 800;
  font-size: clamp(20px, 3.2vw, 32px);
  letter-spacing: -0.02em;
  line-height: 1.25;
  color: var(--white);
}

.page-about .about-chapter__body > p {
  margin: 0 0 18px;
  max-width: var(--about-body-w);
  font-size: 16px;
  line-height: 1.85;
  color: var(--paper);
}

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

.page-about .about-serif {
  font-family: var(--font-serif);
  font-size: clamp(17px, 2.4vw, 22px);
  line-height: 1.7;
  color: var(--cyan-soft);
  padding-left: 16px;
  border-left: 2px solid var(--cyan);
}

/* 图片 */
.page-about .about-figure {
  margin: clamp(24px, 4vw, 40px) 0;
}

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

.page-about .about-figure--slant img {
  clip-path: polygon(0 5%, 100% 0, 100% 95%, 0 100%);
}

.page-about .about-figure__cap {
  margin: 10px 0 0;
  font-size: 12px;
  letter-spacing: 0.04em;
  color: var(--muted);
}

/* 时间线 */
.page-about .about-timeline {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 0;
  margin: clamp(24px, 4vw, 40px) 0 0;
  padding: 0;
  list-style: none;
}

.page-about .about-timeline__item {
  padding: 18px 0 22px 18px;
  border-left: 2px solid var(--moss);
  transition: border-color var(--ease), background var(--ease);
}

.page-about .about-timeline__item:hover {
  border-left-color: var(--cyan);
  background: var(--panel);
}

.page-about .about-timeline__year {
  display: block;
  font-size: 15px;
  letter-spacing: 0.1em;
  color: var(--orange);
}

.page-about .about-timeline__head {
  margin: 8px 0 8px;
  font-family: var(--font-display);
  font-size: 17px;
  font-weight: 800;
  color: var(--white);
}

.page-about .about-timeline__item p {
  margin: 0;
  max-width: 30em;
  font-size: 15px;
  line-height: 1.75;
  color: var(--muted);
}

/* 团队 */
.page-about .about-roster {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 1px;
  margin: 24px 0;
  padding: 0;
  list-style: none;
  background: var(--moss);
  border: var(--about-line);
}

.page-about .about-roster li {
  background: var(--panel);
  padding: 20px 18px 22px;
}

.page-about .about-roster__num {
  display: block;
  font-size: 40px;
  line-height: 1;
  font-weight: 700;
  letter-spacing: -0.03em;
  color: var(--cyan);
}

.page-about .about-roster__label {
  display: block;
  margin-top: 6px;
  font-size: 14px;
  letter-spacing: 0.04em;
  color: var(--white);
}

.page-about .about-roster li p {
  margin: 10px 0 0;
  font-size: 14px;
  line-height: 1.7;
  color: var(--muted);
}

/* 纸白章节 */
.page-about .about-chapter--paper {
  background: var(--paper);
  border-top-color: transparent;
  padding-inline: clamp(16px, 4vw, 40px);
}

.page-about .about-chapter--paper .about-chapter__num {
  color: var(--moss);
}

.page-about .about-chapter--paper .about-chapter__title,
.page-about .about-chapter--paper .about-steps__head {
  color: var(--panel);
}

.page-about .about-chapter--paper .about-chapter__body > p {
  color: var(--moss);
}

.page-about .about-chapter--paper .about-serif {
  color: var(--panel);
  border-left-color: var(--moss);
}

/* 三段内容方法 */
.page-about .about-steps {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 0;
  margin: 8px 0 24px;
  padding: 0;
  list-style: none;
  border-top: 1px solid var(--moss);
}

.page-about .about-steps__item {
  display: grid;
  grid-template-columns: 40px minmax(0, 1fr);
  gap: 4px 14px;
  padding: 18px 0;
  border-bottom: 1px solid var(--moss);
}

.page-about .about-steps__idx {
  font-size: 20px;
  font-weight: 700;
  color: var(--orange);
  line-height: 1.3;
}

.page-about .about-steps__head {
  margin: 0;
  font-family: var(--font-display);
  font-size: 16px;
  font-weight: 800;
  line-height: 1.4;
}

.page-about .about-steps__item p {
  grid-column: 2;
  margin: 0;
  font-size: 15px;
  line-height: 1.75;
  color: var(--moss);
}

/* 合作标签墙 */
.page-about .about-tags {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
  margin: 24px 0;
  padding: 0;
  list-style: none;
}

.page-about .about-tags__item {
  padding: 9px 15px;
  font-size: 14px;
  letter-spacing: 0.02em;
  color: var(--paper);
  border: 1px solid var(--moss);
  background: transparent;
  transition: border-color var(--ease), color var(--ease), transform var(--ease);
}

.page-about .about-tags__item:hover {
  border-color: var(--cyan);
  color: var(--cyan);
  transform: translateY(-2px);
}

/* 数据指标 */
.page-about .about-metrics {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 1px;
  margin: 0 0 24px;
  padding: 0;
  background: var(--moss);
  border: var(--about-line);
}

.page-about .about-metrics__item {
  background: var(--ink);
  padding: 16px 18px;
}

.page-about .about-metrics dt {
  font-size: 13px;
  letter-spacing: 0.04em;
  color: var(--muted);
}

.page-about .about-metrics dd {
  margin: 8px 0 0;
  font-size: 26px;
  font-weight: 700;
  letter-spacing: -0.01em;
  color: var(--cyan);
}

/* 节奏表 */
.page-about .about-rhythm {
  margin: 24px 0;
  padding: 0;
  list-style: none;
  border-top: var(--about-line);
}

.page-about .about-rhythm li {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 6px;
  padding: 16px 0;
  border-bottom: var(--about-line);
}

.page-about .about-rhythm__name {
  font-family: var(--font-display);
  font-size: 16px;
  font-weight: 800;
  color: var(--white);
}

.page-about .about-rhythm__focus {
  font-size: 14px;
  line-height: 1.7;
  color: var(--muted);
}

.page-about .about-rhythm__when {
  font-size: 13px;
  letter-spacing: 0.06em;
  color: var(--orange);
}

/* 下一步 */
.page-about .about-next {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 10px;
  margin-top: clamp(24px, 4vw, 40px);
}

.page-about .about-next a {
  display: flex;
  flex-direction: column;
  gap: 8px;
  padding: 20px 18px;
  color: var(--paper);
  text-decoration: none;
  border: 1px solid var(--moss);
  transition: border-color var(--ease), background var(--ease);
}

.page-about .about-next a .mono {
  font-size: 12px;
  letter-spacing: 0.1em;
  color: var(--muted);
  transition: color var(--ease);
}

.page-about .about-next a strong {
  font-family: var(--font-display);
  font-size: 17px;
  font-weight: 800;
  color: var(--white);
}

.page-about .about-next a:hover,
.page-about .about-next a:focus-visible {
  border-color: var(--cyan);
  background: var(--panel);
}

.page-about .about-next a:hover .mono {
  color: var(--cyan);
}

/* 响应式 */
@media (min-width: 640px) {
  .page-about .about-index ol {
    grid-template-columns: repeat(2, minmax(0, 1fr));
    column-gap: clamp(16px, 3vw, 40px);
  }

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

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

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

  .page-about .about-timeline {
    grid-template-columns: repeat(2, minmax(0, 1fr));
    column-gap: 24px;
  }
}

@media (min-width: 900px) {
  .page-about .about-chapter {
    grid-template-columns: minmax(0, 3fr) minmax(0, 8fr);
    gap: clamp(32px, 6vw, 96px);
  }

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

  .page-about .about-chapter__rail {
    position: sticky;
    top: 32px;
    align-self: start;
    flex-direction: column;
    align-items: flex-start;
    gap: 14px;
  }

  .page-about .about-chapter__rail--row {
    position: static;
    flex-direction: row;
    align-items: flex-end;
    gap: 20px;
  }

  .page-about .about-timeline {
    grid-template-columns: repeat(4, minmax(0, 1fr));
    column-gap: 0;
    border-top: 2px solid var(--moss);
  }

  .page-about .about-timeline__item {
    border-left: 0;
    border-top: 2px solid transparent;
    margin-top: -2px;
    padding: 20px 18px 0 0;
  }

  .page-about .about-timeline__item:hover {
    border-left-color: transparent;
    border-top-color: var(--cyan);
    background: transparent;
  }

  .page-about .about-steps {
    grid-template-columns: repeat(3, minmax(0, 1fr));
    column-gap: 28px;
  }

  .page-about .about-steps__item {
    grid-template-columns: 34px minmax(0, 1fr);
    border-bottom: 0;
    padding-bottom: 0;
  }

  .page-about .about-rhythm li {
    grid-template-columns: 190px minmax(0, 1.7fr) minmax(0, 0.9fr);
    align-items: baseline;
    gap: 24px;
  }

  .page-about .about-rhythm__when {
    text-align: right;
  }

  .page-about .about-figure {
    margin-block: clamp(32px, 5vw, 56px);
  }
}

@media (prefers-reduced-motion: reduce) {
  .page-about .about-index a,
  .page-about .about-tags__item,
  .page-about .about-timeline__item,
  .page-about .about-next a,
  .page-about .about-chapter__num {
    transition: none;
  }

  .page-about .about-index a:hover,
  .page-about .about-tags__item:hover {
    transform: none;
  }
}
<<<END>>>