.page-about {
  --about-rail: clamp(3rem, 7vw, 5.5rem);
  display: block;
  padding-bottom: clamp(2.5rem, 6vw, 4.5rem);
}

.page-about .container {
  max-width: var(--w-page);
  margin-inline: auto;
  padding-inline: var(--pad-x);
}

/* 面包屑 */
.page-about .breadcrumb {
  padding-top: clamp(1.1rem, 3vw, 1.9rem);
}

.page-about .breadcrumb ol {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 0.45rem;
  margin: 0;
  padding: 0;
  list-style: none;
  font-family: var(--f-mono);
  font-size: var(--fs-note);
  letter-spacing: 0.12em;
  color: var(--muted);
}

.page-about .breadcrumb a {
  color: var(--grape-light);
  text-decoration: none;
}

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

.page-about .breadcrumb [aria-current="page"] {
  color: var(--cream);
}

/* 首屏 */
.page-about .about-head {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: clamp(1.1rem, 3vw, 2rem);
  padding-block: clamp(1.6rem, 4vw, 2.8rem) clamp(1.4rem, 3vw, 2.2rem);
  border-bottom: 1px solid var(--line-soft);
}

.page-about .about-kicker {
  margin: 0 0 0.85rem;
  font-family: var(--f-mono);
  font-size: var(--fs-note);
  letter-spacing: 0.24em;
  color: var(--gold);
}

.page-about .page-title {
  margin: 0 0 1.1rem;
  font-family: var(--f-display);
  font-weight: 900;
  font-size: clamp(2.3rem, 7vw, 4.6rem);
  line-height: 1.06;
  letter-spacing: -0.02em;
  background: linear-gradient(100deg, var(--grape-light) 0%, var(--gold) 78%);
  -webkit-background-clip: text;
  background-clip: text;
  color: transparent;
}

.page-about .lede {
  margin: 0;
  max-width: 34em;
  font-size: var(--fs-body);
  line-height: 1.9;
  color: var(--cream);
}

.page-about .about-head .v-note {
  margin: 0;
  align-self: start;
  justify-self: start;
  writing-mode: vertical-rl;
  font-family: var(--f-mono);
  font-size: var(--fs-note);
  letter-spacing: 0.22em;
  color: var(--muted);
  border-left: 1px solid var(--line);
  padding-left: 0.6rem;
}

/* 首屏图像 */
.page-about .about-hero-media {
  margin: clamp(1.4rem, 3vw, 2.2rem) 0 0;
  border: 1px solid var(--line);
}

.page-about .about-hero-media img {
  display: block;
  width: 100%;
  height: auto;
  aspect-ratio: 16 / 7;
  object-fit: cover;
}

.page-about .media-caption {
  display: block;
  padding: 0.6rem 0.75rem;
  border-top: 1px solid var(--line-soft);
  font-family: var(--f-mono);
  font-size: var(--fs-note);
  letter-spacing: 0.08em;
  color: var(--muted);
}

/* 编号章节 */
.page-about .about-chapter {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: clamp(0.9rem, 2.4vw, 1.6rem);
  padding-block: clamp(2rem, 5vw, 3.4rem);
  border-top: 1px solid var(--line-soft);
}

.page-about .chapter-rail {
  display: flex;
  align-items: flex-start;
}

.page-about .chapter-num {
  display: block;
  padding-left: 0.65rem;
  border-left: 1px solid var(--grape);
  font-family: var(--f-mono);
  font-size: var(--fs-note);
  letter-spacing: 0.18em;
  line-height: 1.2;
  color: var(--grape-light);
}

.page-about .chapter-main {
  min-width: 0;
}

.page-about .section-title {
  margin: 0 0 1rem;
  font-family: var(--f-display);
  font-weight: 900;
  font-size: clamp(1.55rem, 3.6vw, 2.4rem);
  line-height: 1.25;
  letter-spacing: -0.01em;
  color: var(--cream);
}

.page-about .about-copy {
  max-width: 34em;
  margin: 0 0 1.05rem;
  font-size: var(--fs-body);
  line-height: 1.9;
  color: var(--cream);
}

.page-about .about-copy + .about-copy {
  color: var(--muted);
}

/* 栏目清单 */
.page-about .column-list {
  list-style: none;
  margin: 1.4rem 0 1.3rem;
  padding: 0;
  border-top: 1px solid var(--line);
}

.page-about .column-item {
  display: grid;
  grid-template-columns: 2.4rem minmax(0, 1fr);
  gap: 0.2rem 0.9rem;
  align-items: baseline;
  padding: 0.85rem 0;
  border-bottom: 1px solid var(--line-soft);
}

.page-about .c-num {
  grid-row: 1;
  font-family: var(--f-mono);
  font-size: var(--fs-note);
  letter-spacing: 0.14em;
  color: var(--gold);
}

.page-about .c-name {
  grid-row: 1;
  font-family: var(--f-display);
  font-size: var(--fs-sub);
  color: var(--cream);
  text-decoration: none;
}

.page-about .c-name:hover,
.page-about .c-name:focus-visible {
  color: var(--gold-pale);
}

.page-about .c-desc {
  grid-column: 2;
  font-size: 0.95rem;
  line-height: 1.8;
  color: var(--muted);
}

/* 版本刻度带 */
.page-about .version-scale {
  margin: 1.7rem 0 1.4rem;
}

.page-about .version-points {
  position: relative;
  display: grid;
  grid-template-columns: repeat(4, minmax(0, 1fr));
  gap: 0.4rem;
  margin: 0;
  padding: 0;
  list-style: none;
}

.page-about .version-points::before {
  content: "";
  position: absolute;
  left: 0;
  right: 0;
  top: 9px;
  height: 1px;
  background: linear-gradient(90deg, var(--line-strong), var(--line-soft));
}

.page-about .version-point {
  position: relative;
  padding-top: 1.75rem;
  display: flex;
  flex-direction: column;
  gap: 0.2rem;
}

.page-about .version-dot {
  position: absolute;
  top: 4px;
  left: 0;
  width: 10px;
  height: 10px;
  background: var(--vine);
  border: 1px solid var(--line-strong);
  transform: rotate(45deg);
}

.page-about .version-point.is-current .version-dot {
  background: var(--gold);
  border-color: var(--gold);
}

.page-about .version-tag {
  font-family: var(--f-mono);
  font-size: 0.6875rem;
  letter-spacing: 0.1em;
  color: var(--grape-light);
}

.page-about .version-point.is-current .version-tag {
  color: var(--gold-pale);
}

.page-about .version-name {
  font-size: 0.8125rem;
  line-height: 1.5;
  color: var(--muted);
}

/* 折叠组 */
.page-about .fold-group {
  border-top: 1px solid var(--line-soft);
}

.page-about .fold-head {
  margin: 0;
  font-weight: 400;
}

.page-about .fold-toggle {
  display: flex;
  align-items: baseline;
  gap: 0.85rem;
  width: 100%;
  padding: 0.9rem 0;
  background: none;
  border: 0;
  text-align: left;
  cursor: pointer;
  font-family: var(--f-body);
  font-size: var(--fs-body);
  color: var(--cream);
}

.page-about .fold-toggle:hover {
  color: var(--gold-pale);
}

.page-about .fold-num {
  flex: none;
  min-width: 3.1rem;
  font-family: var(--f-mono);
  font-size: var(--fs-note);
  letter-spacing: 0.1em;
  color: var(--gold);
}

.page-about .fold-mark {
  flex: none;
  margin-left: auto;
  width: 11px;
  height: 11px;
  border-right: 1px solid var(--line-strong);
  border-bottom: 1px solid var(--line-strong);
  transform: rotate(45deg);
  transition: transform 180ms var(--ease);
}

.page-about .fold-toggle[aria-expanded="true"] .fold-mark {
  transform: rotate(225deg);
}

.page-about .fold-body {
  padding: 0 0 1.1rem 3.95rem;
}

.page-about .fold-body p {
  max-width: 34em;
  margin: 0;
  font-size: 0.975rem;
  line-height: 1.9;
  color: var(--muted);
}

.page-about .version-media {
  margin: 1.6rem 0 0;
  border: 1px solid var(--line-soft);
}

.page-about .version-media img {
  display: block;
  width: 100%;
  height: auto;
  aspect-ratio: 12 / 5;
  object-fit: cover;
  opacity: 0.85;
}

/* 团队 */
.page-about .team-grid {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: clamp(1.4rem, 4vw, 2.6rem);
  margin: 1.6rem 0 0;
}

.page-about .team-col {
  border-top: 1px solid var(--line);
  padding-top: 0.95rem;
}

.page-about .team-count {
  margin: 0 0 0.3rem;
  font-family: var(--f-display);
  font-weight: 900;
  font-size: clamp(2rem, 4vw, 2.9rem);
  line-height: 1;
  color: var(--grape-light);
}

.page-about .team-name {
  margin: 0 0 0.55rem;
  font-family: var(--f-display);
  font-size: var(--fs-sub);
  color: var(--cream);
}

.page-about .team-col p {
  max-width: 26em;
  margin: 0;
  font-size: 0.95rem;
  line-height: 1.85;
  color: var(--muted);
}

.page-about .team-media {
  margin: 1.8rem 0 0;
  max-width: 420px;
  border: 1px solid var(--line-soft);
}

.page-about .team-media img {
  display: block;
  width: 100%;
  height: auto;
  aspect-ratio: 1 / 1;
  object-fit: cover;
}

/* 校对与抽检 */
.page-about .assurance {
  list-style: none;
  margin: 1.4rem 0 0;
  padding: 0;
  border-top: 1px solid var(--line);
}

.page-about .assurance li {
  display: grid;
  grid-template-columns: 1.9rem minmax(0, 1fr);
  gap: 0.2rem 0.85rem;
  padding: 0.9rem 0;
  border-bottom: 1px solid var(--line-soft);
}

.page-about .a-num {
  font-family: var(--f-mono);
  font-size: var(--fs-note);
  letter-spacing: 0.1em;
  color: var(--gold);
}

.page-about .assurance li > span:last-child {
  font-size: 0.975rem;
  line-height: 1.85;
  color: var(--cream);
}

/* 结尾入口 */
.page-about .about-cta {
  margin-top: 1.7rem;
  padding: clamp(1.2rem, 3vw, 1.9rem);
  border: 1px solid var(--line);
  background: linear-gradient(140deg, var(--vine-veil), var(--grape-veil));
}

.page-about .about-cta p {
  max-width: 34em;
  margin: 0 0 1.1rem;
  font-size: var(--fs-body);
  line-height: 1.85;
  color: var(--cream);
}

.page-about .cta-actions {
  display: flex;
  flex-wrap: wrap;
  gap: 0.65rem;
}

.page-about .cta-actions .btn {
  font-family: var(--f-mono);
  font-size: var(--fs-note);
  letter-spacing: 0.12em;
}

/* 章节刻度导航 */
.page-about .scale-nav {
  margin-top: 2rem;
  display: flex;
  flex-wrap: wrap;
  gap: 0.4rem;
}

.page-about .scale-link {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  min-width: 2.4rem;
  padding: 0.3rem 0.4rem;
  border: 1px solid var(--line-soft);
  font-family: var(--f-mono);
  font-size: var(--fs-note);
  letter-spacing: 0.1em;
  color: var(--muted);
  text-decoration: none;
}

.page-about .scale-link:hover,
.page-about .scale-link[aria-current="true"] {
  border-color: var(--line-strong);
  color: var(--gold);
}

/* 焦点样式 */
.page-about a:focus-visible,
.page-about button:focus-visible {
  outline: 2px solid var(--gold);
  outline-offset: 3px;
}

/* 中等宽度 */
@media (min-width: 640px) {
  .page-about .about-head {
    grid-template-columns: minmax(0, 1fr) auto;
    align-items: end;
  }

  .page-about .about-head .v-note {
    justify-self: end;
  }

  .page-about .column-item {
    grid-template-columns: 2.6rem 11rem minmax(0, 1fr);
  }

  .page-about .c-desc {
    grid-column: 3;
  }

  .page-about .team-grid {
    grid-template-columns: 1.3fr 1fr 1.15fr;
  }

  .page-about .version-name {
    font-size: 0.875rem;
  }
}

/* 桌面端 */
@media (min-width: 900px) {
  .page-about .about-chapter {
    grid-template-columns: var(--about-rail) minmax(0, 1fr);
    gap: clamp(1.5rem, 4vw, 3.5rem);
  }

  .page-about .chapter-rail {
    position: sticky;
    top: 2rem;
    border-top: 1px solid var(--line);
    padding-top: 0.7rem;
  }

  .page-about .chapter-num {
    border-left: 0;
    padding-left: 0;
    font-size: 1.05rem;
    letter-spacing: 0.08em;
    color: var(--gold);
  }

  .page-about .version-point {
    padding-top: 2rem;
  }

  .page-about .version-media {
    max-width: 100%;
  }
}

@media (prefers-reduced-motion: reduce) {
  .page-about .fold-mark {
    transition: none;
  }
}
<<<END>>>