.page-about {
  padding-bottom: clamp(56px, 8vw, 104px);
}

.page-about .about-intro {
  max-width: 74ch;
  padding-top: clamp(20px, 4vw, 44px);
}

.page-about .about-intro__title {
  font-family: var(--serif);
  font-weight: 700;
  font-size: clamp(32px, 6.2vw, 60px);
  line-height: 1.14;
  letter-spacing: 0.01em;
  color: var(--paper);
  margin: 12px 0 20px;
}

.page-about .about-intro__lede {
  font-size: clamp(16px, 1.55vw, 18px);
  line-height: 1.85;
  color: var(--silver);
  margin: 0;
}

/* 章节索引 */
.page-about .about-index {
  display: grid;
  grid-template-columns: 1fr;
  gap: 1px;
  margin-top: clamp(30px, 5vw, 52px);
  background: var(--line);
  border: 1px solid var(--line);
}

.page-about .about-index__item {
  display: flex;
  align-items: baseline;
  gap: 12px;
  padding: 16px 18px;
  background: var(--ink-2);
  text-decoration: none;
  color: var(--silver);
  transition: background 0.2s var(--ease), color 0.2s var(--ease);
}

.page-about .about-index__item:hover,
.page-about .about-index__item:focus-visible {
  background: var(--ink-3);
  color: var(--gold-lite);
  box-shadow: inset 0 -1px 0 0 var(--gold);
}

.page-about .about-index__num {
  font-family: var(--mono);
  font-size: 13px;
  letter-spacing: 0.08em;
  color: var(--gold);
}

.page-about .about-index__label {
  font-size: 15px;
}

/* 章节头 */
.page-about .about-sec {
  margin-top: clamp(56px, 9vw, 108px);
}

.page-about .about-sec__head {
  display: flex;
  align-items: flex-start;
  gap: clamp(14px, 2vw, 22px);
  border-top: 1px solid var(--line);
  padding-top: 20px;
  margin-bottom: clamp(24px, 4vw, 40px);
}

.page-about .about-sec__num {
  font-family: var(--mono);
  font-size: clamp(28px, 4.6vw, 50px);
  line-height: 1;
  color: var(--gold);
  letter-spacing: 0.02em;
  flex: none;
}

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

.page-about .about-sec__title {
  font-family: var(--serif);
  font-weight: 600;
  font-size: clamp(23px, 3.4vw, 32px);
  line-height: 1.25;
  color: var(--paper);
  margin: 0 0 8px;
}

.page-about .about-sec__kick {
  font-size: 14px;
  line-height: 1.6;
  color: var(--silver);
  margin: 0;
}

.page-about .about-sec__note {
  display: none;
  font-family: var(--mono);
  font-size: 12px;
  letter-spacing: 0.24em;
  color: var(--line-2);
  writing-mode: vertical-rl;
  text-orientation: upright;
  flex: none;
}

/* 图片 */
.page-about .about-media {
  margin: 0 0 clamp(26px, 4vw, 42px);
}

.page-about .about-media--wide {
  margin-top: clamp(26px, 4vw, 42px);
}

.page-about .about-media--banner {
  margin-top: 0;
}

.page-about .about-media .media__img {
  width: 100%;
  max-width: 100%;
  height: auto;
  display: block;
  object-fit: cover;
  filter: saturate(0.9) contrast(1.02);
}

.page-about .about-media .media__caption {
  font-size: 13px;
  line-height: 1.7;
  color: var(--silver);
  margin-top: 10px;
}

/* 时间线 */
.page-about .about-timeline {
  --tl-col: 62px;
  --tl-gap: 16px;
  display: grid;
  gap: 0;
  border-top: 1px solid var(--line);
}

.page-about .tl-item {
  border-bottom: 1px solid var(--line);
}

.page-about .tl-item > summary {
  display: grid;
  grid-template-columns: var(--tl-col) 1fr;
  gap: 0 var(--tl-gap);
  align-items: stretch;
  padding: 20px 0;
  cursor: pointer;
  list-style: none;
  transition: background 0.2s var(--ease);
}

.page-about .tl-item > summary::-webkit-details-marker {
  display: none;
}

.page-about .tl-item > summary:hover {
  background: var(--ink-2);
}

.page-about .tl-item > summary:focus-visible {
  outline: 1px solid var(--gold);
  outline-offset: 2px;
}

.page-about .tl-item__year {
  font-family: var(--mono);
  font-size: 14px;
  letter-spacing: 0.04em;
  color: var(--gold);
  border-right: 1px solid var(--line);
  padding-right: 12px;
  align-self: stretch;
}

.page-about .tl-item__main {
  display: block;
  min-width: 0;
}

.page-about .tl-item__title {
  font-family: var(--serif);
  font-weight: 600;
  font-size: 18px;
  line-height: 1.4;
  color: var(--paper);
  margin: 0 0 6px;
}

.page-about .tl-item__title::before {
  content: "";
  display: inline-block;
  width: 6px;
  height: 6px;
  background: var(--gold);
  margin-right: 10px;
  vertical-align: 3px;
}

.page-about .tl-item__sum {
  font-size: 15px;
  line-height: 1.75;
  color: var(--silver);
  margin: 0;
}

.page-about .tl-item__body {
  margin-left: calc(var(--tl-col) + var(--tl-gap));
  padding: 0 0 20px;
  font-size: 15px;
  line-height: 1.85;
  color: var(--silver);
  border-left: 1px solid var(--line);
  padding-left: var(--tl-gap);
}

/* 职能小组卡片 */
.page-about .about-groups {
  display: grid;
  grid-template-columns: 1fr;
  gap: clamp(14px, 2vw, 20px);
}

.page-about .group-card {
  display: flex;
  flex-direction: column;
  gap: 12px;
  padding: 24px 20px;
}

.page-about .group-card .card__head {
  display: flex;
  align-items: baseline;
  gap: 12px;
}

.page-about .group-card__idx {
  font-family: var(--mono);
  font-size: 13px;
  letter-spacing: 0.12em;
  color: var(--gold);
  border: 1px solid var(--line);
  padding: 2px 7px;
  flex: none;
}

.page-about .group-card .card__title {
  font-family: var(--serif);
  font-weight: 600;
  font-size: 19px;
  line-height: 1.35;
  color: var(--paper);
  margin: 0;
}

.page-about .group-card .card__text {
  font-size: 15px;
  line-height: 1.82;
  color: var(--silver);
  margin: 0;
}

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

.page-about .group-card__list li {
  position: relative;
  padding-left: 16px;
  font-size: 14px;
  line-height: 1.7;
  color: var(--silver);
}

.page-about .group-card__list li::before {
  content: "";
  position: absolute;
  left: 0;
  top: 10px;
  width: 6px;
  height: 1px;
  background: var(--gold);
}

/* 条款维护 */
.page-about .about-rules {
  margin: 0;
  border-top: 1px solid var(--line);
}

.page-about .about-rules .deflist__row {
  display: grid;
  grid-template-columns: 1fr;
  gap: 8px;
  padding: 20px 0;
  border-bottom: 1px solid var(--line);
}

.page-about .about-rules .deflist__term {
  font-family: var(--serif);
  font-weight: 600;
  font-size: 18px;
  line-height: 1.4;
  color: var(--gold-lite);
}

.page-about .about-rules .deflist__desc {
  margin: 0;
  font-size: 15px;
  line-height: 1.85;
  color: var(--silver);
}

/* 关键数字 */
.page-about .about-stats {
  list-style: none;
  margin: 0 0 clamp(28px, 4vw, 44px);
  padding: 0;
  display: grid;
  grid-template-columns: 1fr;
  gap: 1px;
  background: var(--line);
  border: 1px solid var(--line);
}

.page-about .about-stat {
  display: flex;
  flex-direction: column;
  gap: 8px;
  padding: 22px 18px;
  background: var(--ink-2);
  transition: background 0.2s var(--ease);
}

.page-about .about-stat:hover {
  background: var(--ink-3);
}

.page-about .about-stat__num {
  font-family: var(--mono);
  font-size: clamp(30px, 4.4vw, 44px);
  line-height: 1;
  letter-spacing: -0.01em;
  color: var(--gold-lite);
  transition: color 0.2s var(--ease);
}

.page-about .about-stat:hover .about-stat__num {
  color: var(--gold);
}

.page-about .about-stat__unit {
  font-size: 0.5em;
  margin-left: 3px;
}

.page-about .about-stat__label {
  font-family: var(--serif);
  font-size: 16px;
  color: var(--paper);
}

.page-about .about-stat__note {
  font-size: 13px;
  line-height: 1.65;
  color: var(--silver);
}

/* 服务网络 */
.page-about .about-network {
  display: grid;
  grid-template-columns: 1fr;
  gap: 1px;
  background: var(--line);
  border: 1px solid var(--line);
}

.page-about .about-network__col {
  background: var(--ink);
  padding: 22px 20px;
}

.page-about .about-network__title {
  font-family: var(--serif);
  font-weight: 600;
  font-size: 17px;
  line-height: 1.4;
  color: var(--paper);
  margin: 0 0 8px;
}

.page-about .about-network__col p {
  margin: 0;
  font-size: 15px;
  line-height: 1.8;
  color: var(--silver);
}

.page-about .about-network__foot {
  margin: clamp(20px, 3vw, 30px) 0 0;
  padding-left: 16px;
  border-left: 1px solid var(--gold);
  font-size: 15px;
  line-height: 1.85;
  color: var(--silver);
  max-width: 70ch;
}

/* 合作伙伴 */
.page-about .about-partners {
  display: grid;
  grid-template-columns: 1fr;
  gap: 1px;
  background: var(--line);
  border: 1px solid var(--line);
}

.page-about .about-partner {
  background: var(--ink-2);
  padding: 24px 20px;
  transition: background 0.2s var(--ease), box-shadow 0.2s var(--ease);
}

.page-about .about-partner:hover {
  background: var(--ink-3);
  box-shadow: inset 0 0 0 1px var(--gold);
}

.page-about .about-partner__title {
  font-family: var(--serif);
  font-weight: 600;
  font-size: 18px;
  line-height: 1.4;
  color: var(--paper);
  margin: 0 0 10px;
}

.page-about .about-partner p {
  margin: 0;
  font-size: 15px;
  line-height: 1.8;
  color: var(--silver);
}

.page-about .about-honor {
  display: flex;
  flex-wrap: wrap;
  align-items: flex-start;
  gap: 12px 16px;
  margin-top: clamp(22px, 3vw, 32px);
  padding: 20px;
  background: var(--ink-2);
  border-left: 1px solid var(--gold);
}

.page-about .about-honor p {
  margin: 0;
  flex: 1 1 260px;
  font-size: 15px;
  line-height: 1.8;
  color: var(--silver);
}

/* 结尾入口 */
.page-about .about-cta {
  margin-top: clamp(56px, 9vw, 104px);
  border-top: 1px solid var(--line);
  padding-top: clamp(26px, 4vw, 40px);
  display: grid;
  grid-template-columns: 1fr;
  gap: 24px;
  align-items: end;
}

.page-about .about-cta__title {
  font-family: var(--serif);
  font-weight: 600;
  font-size: clamp(22px, 3.2vw, 30px);
  line-height: 1.3;
  color: var(--paper);
  margin: 0 0 12px;
}

.page-about .about-cta__text {
  margin: 0;
  max-width: 62ch;
  font-size: 15px;
  line-height: 1.85;
  color: var(--silver);
}

.page-about .about-cta__actions {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
}

.page-about .about-cta__actions .btn {
  flex: 0 1 auto;
}

/* 响应式 */
@media (min-width: 640px) {
  .page-about .about-stats {
    grid-template-columns: repeat(2, 1fr);
  }
  .page-about .about-index {
    grid-template-columns: repeat(2, 1fr);
  }
}

@media (min-width: 780px) {
  .page-about .about-index {
    grid-template-columns: repeat(auto-fit, minmax(150px, 1fr));
  }
  .page-about .about-network {
    grid-template-columns: repeat(2, 1fr);
  }
  .page-about .about-partners {
    grid-template-columns: repeat(3, 1fr);
  }
  .page-about .about-rules .deflist__row {
    grid-template-columns: minmax(180px, 220px) 1fr;
    gap: 0 32px;
    align-items: start;
  }
}

@media (min-width: 900px) {
  .page-about .about-sec__note {
    display: block;
  }
  .page-about .about-groups {
    grid-template-columns: repeat(12, 1fr);
  }
  .page-about .group-card--a {
    grid-column: span 5;
  }
  .page-about .group-card--b {
    grid-column: span 7;
  }
  .page-about .group-card--c {
    grid-column: span 4;
  }
  .page-about .group-card--d {
    grid-column: span 8;
  }
  .page-about .about-cta {
    grid-template-columns: 1fr auto;
    gap: 40px;
  }
}

@media (min-width: 980px) {
  .page-about .about-stats {
    grid-template-columns: repeat(5, 1fr);
  }
  .page-about .about-network {
    grid-template-columns: repeat(4, 1fr);
  }
  .page-about .about-timeline {
    --tl-col: 88px;
    --tl-gap: 22px;
  }
  .page-about .tl-item__body {
    max-width: 68ch;
  }
}
<<<END>>>