.page-about {
  --about-bodyw: 68ch;
  color: var(--paper);
  padding-bottom: clamp(48px, 8vw, 96px);
}

.page-about .eyebrow {
  font-family: var(--font-data);
  font-size: 12px;
  letter-spacing: 0.24em;
  color: var(--sand);
  margin: 0;
  text-transform: uppercase;
}

/* ---------- 首屏 ---------- */
.page-about .about-hero {
  display: grid;
  gap: var(--gap);
  padding-block: clamp(24px, 4vw, 44px) clamp(36px, 6vw, 72px);
}

.page-about .about-hero__lead {
  display: grid;
  align-content: start;
  gap: 16px;
}

.page-about h1 {
  margin: 0;
  font-family: var(--font-head);
  font-weight: 900;
  font-size: clamp(2rem, 6.4vw, 3.6rem);
  line-height: 1.14;
  letter-spacing: 0.03em;
  color: var(--paper);
  max-width: 16em;
}

.page-about .about-hero__intro {
  margin: 0;
  max-width: 46ch;
  font-family: var(--font-body);
  font-size: clamp(15px, 1.7vw, 17px);
  line-height: 1.75;
  color: var(--mist);
}

.page-about .about-hero__note {
  display: none;
  margin: 0;
  writing-mode: vertical-rl;
  font-family: var(--font-data);
  font-size: 11px;
  letter-spacing: 0.32em;
  color: var(--mintdark);
}

.page-about .about-hero__media {
  margin: 0;
  border-radius: 4px 28px 4px 4px;
}

.page-about .about-hero__media img {
  display: block;
  width: 100%;
  height: auto;
  object-fit: cover;
  aspect-ratio: 3 / 2;
}

/* ---------- 首屏数字 ---------- */
.page-about .about-stats {
  margin: 0;
  display: grid;
  gap: 14px;
  grid-template-columns: 1fr;
  border-top: 1px solid var(--steel);
  padding-top: 18px;
}

.page-about .about-stats .stat {
  display: grid;
  gap: 4px;
  padding-left: 14px;
  border-left: 2px solid var(--sand);
}

.page-about .about-stats .stat__num {
  margin: 0;
  font-family: var(--font-data);
  font-weight: 700;
  font-size: clamp(1.5rem, 4.4vw, 2rem);
  letter-spacing: 0.02em;
  color: var(--sand);
}

.page-about .about-stats .stat__label {
  margin: 0;
  font-family: var(--font-body);
  font-size: 13px;
  line-height: 1.6;
  color: var(--mist);
}

/* ---------- 主题筛选 ---------- */
.page-about .about-filter {
  display: flex;
  gap: 8px;
  overflow-x: auto;
  padding-bottom: 4px;
  margin-bottom: clamp(20px, 3vw, 32px);
  border-bottom: 1px solid var(--steel);
  padding-bottom: 14px;
  scrollbar-width: thin;
}

.page-about .about-filter .filter-btn {
  flex: 0 0 auto;
  font-family: var(--font-head);
  font-size: 13px;
  font-weight: 700;
  letter-spacing: 0.06em;
  color: var(--mist);
  background: transparent;
  border: 1px solid var(--steel);
  border-radius: 999px;
  padding: 8px 16px;
  cursor: pointer;
  transition: color 0.2s ease, border-color 0.2s ease, background 0.2s ease;
}

.page-about .about-filter .filter-btn[aria-pressed="true"] {
  color: var(--deep);
  background: var(--sand);
  border-color: var(--sand);
}

.page-about .about-filter .filter-btn:hover {
  border-color: var(--coral);
  color: var(--paper);
}

.page-about .about-filter .filter-btn[aria-pressed="true"]:hover {
  color: var(--deep);
}

/* ---------- 主体双栏 ---------- */
.page-about .about-layout {
  display: grid;
  gap: clamp(24px, 4vw, 48px);
}

.page-about .about-index__kicker {
  margin: 0 0 10px;
  font-family: var(--font-data);
  font-size: 11px;
  letter-spacing: 0.26em;
  color: var(--sand);
}

.page-about .about-index ol {
  display: flex;
  gap: 8px;
  overflow-x: auto;
  list-style: none;
  margin: 0;
  padding: 0 0 6px;
  scrollbar-width: thin;
}

.page-about .about-index li {
  flex: 0 0 auto;
}

.page-about .about-index a {
  display: inline-flex;
  align-items: baseline;
  gap: 8px;
  padding: 6px 12px;
  font-family: var(--font-head);
  font-size: 13px;
  font-weight: 700;
  letter-spacing: 0.04em;
  color: var(--mist);
  text-decoration: none;
  border-left: 2px solid transparent;
  border-radius: 0 3px 3px 0;
  white-space: nowrap;
  transition: color 0.2s ease, border-color 0.2s ease;
}

.page-about .about-index a span {
  font-family: var(--font-data);
  font-size: 11px;
  color: var(--steel);
}

.page-about .about-index a:hover,
.page-about .about-index a.is-active {
  color: var(--sand);
  border-left-color: var(--sand);
}

.page-about .about-index a.is-active span {
  color: var(--mint);
}

/* ---------- 章节 ---------- */
.page-about .about-chapter {
  padding-block: clamp(32px, 5vw, 60px);
  border-top: 1px solid var(--steel);
}

.page-about .about-chapter:first-child {
  border-top: 0;
  padding-top: 0;
}

.page-about .about-chapter.is-filtered {
  display: none;
}

.page-about .about-chapter__head {
  display: flex;
  align-items: baseline;
  gap: 16px;
  margin-bottom: 18px;
}

.page-about .about-chapter__num {
  font-family: var(--font-data);
  font-weight: 700;
  font-size: clamp(2rem, 7vw, 3.6rem);
  line-height: 0.82;
  letter-spacing: -0.02em;
  color: var(--sand);
  opacity: 0.85;
}

.page-about .about-chapter h2 {
  margin: 0;
  font-family: var(--font-head);
  font-weight: 900;
  font-size: clamp(1.35rem, 3.2vw, 2rem);
  line-height: 1.25;
  letter-spacing: 0.04em;
  color: var(--paper);
}

.page-about .about-body p {
  margin: 0 0 16px;
  max-width: var(--about-bodyw);
  font-family: var(--font-body);
  font-size: clamp(15px, 1.7vw, 17px);
  line-height: 1.78;
  color: var(--paper);
}

/* ---------- 引用摘要 ---------- */
.page-about .about-quote {
  margin: 24px 0 0;
  padding: clamp(18px, 3vw, 28px);
  max-width: 46ch;
  background: var(--sandpale);
  border-radius: 2px 22px 22px 2px;
  border-left: 5px solid var(--coral);
}

.page-about .about-quote p {
  margin: 0;
  max-width: none;
  font-family: var(--font-head);
  font-weight: 800;
  font-size: clamp(1.05rem, 2.4vw, 1.35rem);
  line-height: 1.5;
  letter-spacing: 0.02em;
  color: var(--ink2);
}

/* ---------- 人群卡片 ---------- */
.page-about .about-cards {
  display: grid;
  gap: 12px;
  margin: 8px 0 22px;
  grid-template-columns: 1fr;
}

.page-about .about-card {
  position: relative;
  padding: 18px 18px 18px 20px;
  background: var(--ink2);
  border: 1px solid var(--steel);
  border-radius: 3px 16px 16px 3px;
  transition: border-color 0.25s ease, transform 0.25s ease;
}

.page-about .about-card::before {
  content: "";
  position: absolute;
  left: 0;
  top: 16px;
  bottom: 16px;
  width: 3px;
  background: var(--mintdark);
  border-radius: 2px;
}

.page-about .about-card:hover {
  border-color: var(--sand);
  transform: translateY(-3px);
}

.page-about .about-card h3 {
  margin: 0 0 8px;
  font-family: var(--font-head);
  font-weight: 800;
  font-size: 1rem;
  letter-spacing: 0.05em;
  color: var(--sand);
}

.page-about .about-card p {
  margin: 0;
  max-width: none;
  font-size: 14px;
  line-height: 1.7;
  color: var(--mist);
}

/* ---------- 方法章节 ---------- */
.page-about .about-method {
  display: grid;
  gap: clamp(20px, 3vw, 32px);
}

.page-about .about-steps {
  list-style: none;
  margin: 4px 0 20px;
  padding: 0;
  display: grid;
  gap: 2px;
}

.page-about .about-steps li {
  display: flex;
  gap: 14px;
  padding: 14px 0;
  border-bottom: 1px dashed var(--steel);
}

.page-about .about-steps__num {
  flex: 0 0 auto;
  font-family: var(--font-data);
  font-weight: 700;
  font-size: 13px;
  letter-spacing: 0.06em;
  color: var(--mint);
  padding-top: 3px;
}

.page-about .about-steps h3 {
  margin: 0 0 4px;
  font-family: var(--font-head);
  font-weight: 800;
  font-size: 1rem;
  letter-spacing: 0.04em;
  color: var(--paper);
}

.page-about .about-steps p {
  margin: 0;
  max-width: 52ch;
  font-size: 14px;
  line-height: 1.7;
  color: var(--mist);
}

.page-about .about-method__media {
  margin: 0;
  border-radius: 24px 4px 4px 4px;
}

.page-about .about-method__media img {
  display: block;
  width: 100%;
  height: auto;
  object-fit: cover;
  aspect-ratio: 4 / 3;
}

.page-about .media__caption {
  display: block;
  margin-top: 8px;
  font-family: var(--font-data);
  font-size: 11px;
  letter-spacing: 0.1em;
  color: var(--mist);
}

/* ---------- 版本时间轴 ---------- */
.page-about .about-timeline {
  list-style: none;
  margin: 20px 0 0;
  padding: 0;
  display: grid;
  gap: 10px;
  grid-template-columns: 1fr;
}

.page-about .about-version {
  height: 100%;
  background: var(--ink2);
  border: 1px solid var(--steel);
  border-radius: 14px;
  padding: 14px 16px;
  transition: border-color 0.22s ease, background 0.22s ease;
}

.page-about .about-version[open] {
  border-color: var(--sand);
  background: var(--tactic);
}

.page-about .about-version summary {
  display: flex;
  align-items: baseline;
  gap: 10px;
  cursor: pointer;
  list-style: none;
}

.page-about .about-version summary::-webkit-details-marker {
  display: none;
}

.page-about .about-version__no {
  flex: 0 0 auto;
  font-family: var(--font-data);
  font-weight: 700;
  font-size: 12px;
  letter-spacing: 0.08em;
  color: var(--mint);
}

.page-about .about-version h3 {
  margin: 0;
  font-family: var(--font-head);
  font-weight: 800;
  font-size: 14px;
  line-height: 1.5;
  letter-spacing: 0.03em;
  color: var(--paper);
}

.page-about .about-version p {
  margin: 10px 0 0;
  max-width: none;
  font-size: 13px;
  line-height: 1.7;
  color: var(--mist);
}

/* ---------- 共建章节 ---------- */
.page-about .about-eco__media {
  margin: 20px 0 22px;
  border-radius: 4px 4px 26px 4px;
}

.page-about .about-eco__media img {
  display: block;
  width: 100%;
  height: auto;
  object-fit: cover;
  aspect-ratio: 3 / 2;
}

/* ---------- 结尾入口 ---------- */
.page-about .about-next {
  margin-top: clamp(28px, 4vw, 44px);
  padding: clamp(22px, 4vw, 36px);
  background: var(--tactic);
  border-radius: 4px 30px 4px 30px;
  border-left: 4px solid var(--sand);
}

.page-about .about-next h2 {
  margin: 0 0 10px;
  font-family: var(--font-head);
  font-weight: 900;
  font-size: clamp(1.3rem, 3vw, 1.85rem);
  line-height: 1.3;
  letter-spacing: 0.04em;
  color: var(--paper);
}

.page-about .about-next p {
  margin: 0 0 20px;
  max-width: 58ch;
  font-family: var(--font-body);
  font-size: 15px;
  line-height: 1.75;
  color: var(--mist);
}

.page-about .about-next__links {
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
}

.page-about .about-next__links .btn {
  font-family: var(--font-head);
  font-size: 13px;
  font-weight: 800;
  letter-spacing: 0.06em;
  padding: 11px 20px;
  border-radius: 999px;
  text-decoration: none;
  transition: transform 0.2s ease, background 0.2s ease, border-color 0.2s ease;
}

.page-about .about-next__links .btn--primary {
  background: var(--sand);
  color: var(--deep);
  border: 1px solid var(--sand);
}

.page-about .about-next__links .btn--ghost {
  background: transparent;
  color: var(--paper);
  border: 1px solid var(--steel);
}

.page-about .about-next__links .btn--quiet {
  background: transparent;
  color: var(--mint);
  border: 1px solid transparent;
  padding-inline: 6px;
}

.page-about .about-next__links .btn:hover {
  transform: translateY(-2px);
}

.page-about .about-next__links .btn--ghost:hover {
  border-color: var(--sand);
}

.page-about .about-next__links .btn--quiet:hover {
  color: var(--sand);
}

/* ---------- 平板与桌面 ---------- */
@media (min-width: 700px) {
  .page-about .about-stats {
    grid-template-columns: repeat(3, minmax(0, 1fr));
    gap: 18px;
  }

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

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

@media (min-width: 920px) {
  .page-about .about-hero {
    grid-template-columns: minmax(0, 1.02fr) minmax(0, 0.98fr);
    align-items: start;
    column-gap: clamp(24px, 3.5vw, 48px);
  }

  .page-about .about-hero__lead {
    grid-row: 1 / span 2;
  }

  .page-about .about-hero__note {
    display: block;
    position: absolute;
    right: -6px;
    top: 8px;
  }

  .page-about .about-hero__lead {
    position: relative;
    padding-right: 26px;
  }

  .page-about .about-hero__media img {
    aspect-ratio: 4 / 5;
  }

  .page-about .about-stats {
    grid-row: 2;
    align-self: start;
  }

  .page-about .about-layout {
    grid-template-columns: 208px minmax(0, 1fr);
    align-items: start;
  }

  .page-about .about-index {
    position: sticky;
    top: calc(var(--topbar) + 22px);
    padding-right: 12px;
  }

  .page-about .about-index ol {
    display: grid;
    gap: 2px;
    overflow: visible;
    padding-bottom: 0;
  }

  .page-about .about-index a {
    display: flex;
    white-space: normal;
    padding: 9px 0 9px 12px;
    line-height: 1.45;
  }

  .page-about .about-method {
    grid-template-columns: minmax(0, 1.15fr) minmax(0, 0.85fr);
    align-items: start;
  }

  .page-about .about-method__media {
    position: sticky;
    top: calc(var(--topbar) + 22px);
  }

  .page-about .about-eco__media {
    margin-left: clamp(-40px, -3vw, 0px);
  }
}

@media (prefers-reduced-motion: reduce) {
  .page-about .about-card,
  .page-about .about-next__links .btn,
  .page-about .about-filter .filter-btn {
    transition: none;
  }

  .page-about .about-card:hover,
  .page-about .about-next__links .btn:hover {
    transform: none;
  }
}
<<<PAGE_CSS_END>>>