.page-about {
  --about-hair: 1px solid var(--mist);
  --about-ink-soft: #22323A;
  background: var(--paper);
  color: var(--body-text);
  font-family: var(--font-body);
  font-size: 17px;
  line-height: 1.85;
  overflow-x: clip;
}

.page-about .about-crumb {
  padding-top: 18px;
  padding-bottom: 6px;
}

.page-about .about-foot-crumb {
  padding-top: 8px;
  padding-bottom: 48px;
}

/* ---------- Hero ---------- */
.page-about .about-hero__media {
  position: relative;
  height: clamp(190px, 30vw, 400px);
  overflow: hidden;
  background: var(--cyan);
  border-top: 4px solid var(--cyan);
}

.page-about .about-hero__media img {
  display: block;
  width: 100%;
  height: 100%;
  object-fit: cover;
  object-position: center 40%;
}

.page-about .about-hero__inner {
  display: grid;
  gap: clamp(26px, 4vw, 48px);
  padding-top: clamp(26px, 4vw, 52px);
  padding-bottom: clamp(30px, 4.4vw, 56px);
}

.page-about .about-hero__eyebrow {
  margin: 0 0 14px;
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.16em;
  color: var(--teal);
  text-transform: uppercase;
}

.page-about .about-hero h1 {
  margin: 0;
  font-family: var(--font-display);
  font-weight: 800;
  font-size: clamp(31px, 5.4vw, 58px);
  line-height: 1.16;
  letter-spacing: -0.02em;
  color: var(--ink);
}

.page-about .about-hero__lead {
  margin: 20px 0 0;
  max-width: 34em;
  font-size: clamp(16px, 1.6vw, 18px);
  line-height: 1.85;
  color: var(--about-ink-soft);
}

.page-about .about-hero__stats {
  list-style: none;
  margin: 0;
  padding: 18px 0 0;
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 18px 14px;
  border-top: var(--about-hair);
}

.page-about .about-hero__stat {
  display: flex;
  flex-direction: column;
  gap: 4px;
}

.page-about .about-hero__num {
  font-family: var(--font-display);
  font-weight: 800;
  font-size: clamp(24px, 2.8vw, 32px);
  line-height: 1.1;
  letter-spacing: -0.02em;
  color: var(--cyan);
}

.page-about .about-hero__key {
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: 0.14em;
  color: var(--steel);
}

/* ---------- 章节索引 ---------- */
.page-about .about-toc {
  border-top: var(--about-hair);
  border-bottom: var(--about-hair);
  background: var(--sand-soft);
}

.page-about .about-toc__inner {
  display: flex;
  gap: 22px;
  overflow-x: auto;
  padding-top: 14px;
  padding-bottom: 14px;
}

.page-about .about-toc__link {
  display: inline-flex;
  align-items: baseline;
  gap: 7px;
  flex: 0 0 auto;
  font-size: 14px;
  color: var(--body-text);
  text-decoration: none;
  white-space: nowrap;
  padding-bottom: 3px;
  border-bottom: 1px solid transparent;
  transition: color 0.2s var(--ease), border-color 0.2s var(--ease);
}

.page-about .about-toc__link:hover {
  color: var(--cyan);
  border-bottom-color: var(--gold);
}

.page-about .about-toc__num {
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: 0.16em;
  color: var(--steel);
}

/* ---------- 章节通用 ---------- */
.page-about .about-chapter {
  padding: clamp(48px, 7vw, 96px) 0;
  border-top: var(--about-hair);
}

.page-about .about-chapter--band {
  background:
    linear-gradient(90deg, rgba(199, 154, 62, 0.12), rgba(46, 139, 122, 0.1) 55%, rgba(14, 59, 74, 0.06));
}

.page-about .about-chapter__head {
  display: grid;
  grid-template-columns: auto minmax(0, 1fr);
  gap: 10px 16px;
  align-items: start;
  margin-bottom: clamp(24px, 3.6vw, 46px);
}

.page-about .about-num {
  font-family: var(--font-mono);
  font-size: clamp(26px, 3.4vw, 34px);
  line-height: 1;
  letter-spacing: 0.08em;
  color: var(--gold-deep);
}

.page-about .about-chapter__title {
  margin: 0;
  font-family: var(--font-display);
  font-weight: 800;
  font-size: clamp(23px, 3.2vw, 38px);
  line-height: 1.28;
  letter-spacing: -0.018em;
  color: var(--ink);
}

.page-about .about-chapter__note {
  grid-column: 2;
  margin: 0;
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.1em;
  line-height: 1.7;
  color: var(--steel);
}

.page-about .about-chapter__body {
  display: grid;
  gap: clamp(22px, 3vw, 40px);
}

.page-about .about-chapter__body--single {
  gap: clamp(18px, 2.4vw, 28px);
}

.page-about .about-prose p {
  margin: 0 0 18px;
  max-width: 38em;
  font-size: 17px;
  line-height: 1.9;
}

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

/* ---------- 侧栏说明牌 ---------- */
.page-about .about-sidenote {
  border-left: 2px solid var(--gold);
  background: var(--sand-soft);
  padding: 18px 18px 20px;
}

.page-about .about-sidenote--plain {
  border-left-color: var(--mist);
  background: transparent;
  padding: 0;
}

.page-about .about-sidenote--quote p {
  margin: 0;
  font-size: 15px;
  line-height: 1.85;
  color: var(--about-ink-soft);
}

.page-about .about-sidenote__label {
  margin: 0 0 12px;
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: 0.18em;
  color: var(--steel);
}

.page-about .about-facts {
  margin: 0;
  display: grid;
  gap: 10px;
}

.page-about .about-facts__row {
  display: flex;
  justify-content: space-between;
  gap: 12px;
  padding-bottom: 9px;
  border-bottom: 1px solid var(--mist);
  font-size: 13px;
}

.page-about .about-facts__row:last-child {
  border-bottom: 0;
  padding-bottom: 0;
}

.page-about .about-facts dt {
  color: var(--steel);
  flex: 0 0 auto;
}

.page-about .about-facts dd {
  margin: 0;
  font-weight: 500;
  text-align: right;
  color: var(--ink);
}

/* ---------- 三类归档 ---------- */
.page-about .about-pillars {
  display: grid;
  gap: 1px;
  background: var(--mist);
  border: var(--about-hair);
}

.page-about .about-pillar {
  background: var(--paper);
  padding: 22px 20px 24px;
  transition: background 0.24s var(--ease);
}

.page-about .about-pillar:hover {
  background: #FFFFFF;
}

.page-about .about-pillar__label {
  margin: 0 0 10px;
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: 0.16em;
  color: var(--gold-deep);
}

.page-about .about-pillar__title {
  margin: 0 0 10px;
  font-family: var(--font-display);
  font-weight: 800;
  font-size: 20px;
  line-height: 1.35;
  color: var(--ink);
}

.page-about .about-pillar__text {
  margin: 0;
  font-size: 15px;
  line-height: 1.85;
  color: var(--about-ink-soft);
}

/* ---------- 时间轴章节 ---------- */
.page-about .about-chapter--timeline {
  padding-top: 0;
  border-top: 0;
}

.page-about .about-band-figure {
  margin: 0 0 clamp(30px, 4.4vw, 56px);
  height: clamp(120px, 16vw, 200px);
  overflow: hidden;
  background: var(--cyan);
}

.page-about .about-band-figure img {
  display: block;
  width: 100%;
  height: 100%;
  object-fit: cover;
}

.page-about .about-chapter__wide {
  max-width: 1320px;
}

.page-about .about-timeline {
  list-style: none;
  margin: 0;
  padding: 0;
  display: grid;
  gap: 0;
}

.page-about .about-timeline__item {
  position: relative;
  padding: 0 0 26px 26px;
  border-left: 1px solid var(--mist);
}

.page-about .about-timeline__item:last-child {
  padding-bottom: 0;
}

.page-about .about-timeline__item::before {
  content: "";
  position: absolute;
  left: -4.5px;
  top: 8px;
  width: 8px;
  height: 8px;
  background: var(--steel);
}

.page-about .about-timeline__item:nth-child(3)::before,
.page-about .about-timeline__item:nth-child(4)::before {
  background: var(--gold);
}

.page-about .about-timeline__sum {
  display: flex;
  align-items: baseline;
  gap: 12px;
  cursor: pointer;
  list-style: none;
  padding: 2px 0 6px;
}

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

.page-about .about-timeline__stamp {
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.14em;
  color: var(--gold-deep);
  flex: 0 0 auto;
}

.page-about .about-timeline__name {
  font-family: var(--font-display);
  font-weight: 800;
  font-size: 17px;
  line-height: 1.5;
  color: var(--ink);
  border-bottom: 1px dashed transparent;
  transition: border-color 0.2s var(--ease), color 0.2s var(--ease);
}

.page-about .about-timeline__sum:hover .about-timeline__name {
  color: var(--cyan);
  border-bottom-color: var(--gold);
}

.page-about .about-timeline__body {
  padding: 4px 0 2px;
}

.page-about .about-timeline__body p {
  margin: 0;
  font-size: 14px;
  line-height: 1.9;
  color: var(--about-ink-soft);
}

/* ---------- 团队 ---------- */
.page-about .about-chapter__body--team {
  align-items: start;
}

.page-about .about-team__bars {
  list-style: none;
  margin: 0;
  padding: 0;
  display: grid;
  gap: 22px;
}

.page-about .about-team__row {
  padding-bottom: 4px;
}

.page-about .about-team__head {
  display: flex;
  justify-content: space-between;
  align-items: baseline;
  gap: 12px;
  margin-bottom: 8px;
}

.page-about .about-team__label {
  font-family: var(--font-display);
  font-weight: 800;
  font-size: 17px;
  color: var(--ink);
  transition: color 0.2s var(--ease);
}

.page-about .about-team__value {
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.12em;
  color: var(--steel);
}

.page-about .about-team__track {
  height: 10px;
  background: var(--sand);
  overflow: hidden;
}

.page-about .about-team__fill {
  display: block;
  height: 100%;
  background: var(--cyan);
  transition: filter 0.24s var(--ease), background 0.24s var(--ease);
}

.page-about .about-team__row:nth-child(1) .about-team__fill { width: 57.1%; }
.page-about .about-team__row:nth-child(2) .about-team__fill { width: 25%; background: var(--teal); }
.page-about .about-team__row:nth-child(3) .about-team__fill { width: 17.9%; background: var(--gold-deep); }

.page-about .about-team__row:hover .about-team__label {
  color: var(--cyan);
}

.page-about .about-team__row:hover .about-team__fill {
  filter: brightness(1.12) saturate(1.15);
}

.page-about .about-team__desc {
  margin: 10px 0 0;
  font-size: 14px;
  line-height: 1.85;
  color: var(--steel);
}

.page-about .about-team__figure {
  margin: 0;
}

.page-about .about-team__figure img {
  display: block;
  width: 100%;
  height: auto;
  object-fit: cover;
  background: var(--mist);
}

.page-about .about-team__figure figcaption {
  margin-top: 12px;
  padding-left: 12px;
  border-left: 2px solid var(--gold);
  font-size: 13px;
  line-height: 1.8;
  color: var(--steel);
}

/* ---------- 折叠 ---------- */
.page-about .about-fold {
  border-bottom: var(--about-hair);
  padding: 14px 0;
}

.page-about .about-fold:first-child {
  border-top: var(--about-hair);
}

.page-about .about-fold__sum {
  list-style: none;
  cursor: pointer;
  display: flex;
  align-items: baseline;
  gap: 10px;
  font-family: var(--font-display);
  font-weight: 800;
  font-size: 15px;
  line-height: 1.6;
  color: var(--ink);
  transition: color 0.2s var(--ease);
}

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

.page-about .about-fold__sum::before {
  content: "+";
  flex: 0 0 auto;
  font-family: var(--font-mono);
  font-size: 14px;
  color: var(--gold-deep);
}

.page-about .about-fold[open] > .about-fold__sum::before {
  content: "−";
}

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

.page-about .about-fold__body {
  padding: 10px 0 4px;
}

.page-about .about-fold__body p {
  margin: 0;
  font-size: 14px;
  line-height: 1.9;
  color: var(--about-ink-soft);
}

.page-about .about-steps {
  margin: 0;
  padding-left: 1.2em;
  font-size: 14px;
  line-height: 1.9;
  color: var(--about-ink-soft);
}

.page-about .about-steps li {
  margin-bottom: 6px;
}

.page-about .about-steps li:last-child {
  margin-bottom: 0;
}

/* ---------- 协作机构 ---------- */
.page-about .about-partners {
  list-style: none;
  margin: 0;
  padding: 0;
  border-top: var(--about-hair);
}

.page-about .about-partners__item {
  display: grid;
  gap: 4px;
  padding: 18px 0;
  border-bottom: var(--about-hair);
}

.page-about .about-partners__key {
  font-family: var(--font-display);
  font-weight: 800;
  font-size: 17px;
  color: var(--ink);
}

.page-about .about-partners__key::before {
  content: "";
  display: inline-block;
  width: 8px;
  height: 8px;
  margin-right: 10px;
  background: var(--pine);
  vertical-align: 2px;
}

.page-about .about-partners__val {
  font-size: 15px;
  line-height: 1.85;
  color: var(--about-ink-soft);
}

/* ---------- 准则 ---------- */
.page-about .about-chapter--principles {
  background: var(--paper);
}

.page-about .about-principles {
  list-style: none;
  margin: 0;
  padding: 0;
}

.page-about .about-principles__line {
  display: flex;
  align-items: baseline;
  gap: 14px;
  padding: clamp(18px, 2.8vw, 32px) 0;
  border-top: 1px solid var(--mist);
  font-family: var(--font-display);
  font-weight: 800;
  font-size: clamp(21px, 3.4vw, 36px);
  line-height: 1.35;
  letter-spacing: -0.02em;
  color: var(--ink);
}

.page-about .about-principles__line:last-child {
  border-bottom: 1px solid var(--mist);
}

.page-about .about-principles__mark {
  flex: 0 0 auto;
  width: 10px;
  height: 10px;
  background: var(--gold);
  transform: translateY(-2px);
}

/* ---------- 下一步 ---------- */
.page-about .about-next {
  padding: clamp(48px, 7vw, 92px) 0 clamp(40px, 5vw, 72px);
  border-top: var(--about-hair);
}

.page-about .about-next__title {
  margin: 0 0 clamp(20px, 3vw, 34px);
  font-family: var(--font-display);
  font-weight: 800;
  font-size: clamp(21px, 2.6vw, 28px);
  line-height: 1.3;
  color: var(--ink);
}

.page-about .about-next__grid {
  display: grid;
  gap: 1px;
  background: var(--mist);
  border: var(--about-hair);
}

.page-about .about-next__card {
  display: grid;
  gap: 6px;
  padding: 20px 18px 22px;
  background: var(--paper);
  text-decoration: none;
  transition: background 0.24s var(--ease);
}

.page-about .about-next__card:hover {
  background: #FFFFFF;
}

.page-about .about-next__label {
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: 0.18em;
  color: var(--steel);
}

.page-about .about-next__name {
  font-family: var(--font-display);
  font-weight: 800;
  font-size: 17px;
  line-height: 1.5;
  color: var(--cyan);
}

.page-about .about-next__card:hover .about-next__name {
  color: var(--teal);
}

.page-about .about-next__hint {
  font-size: 14px;
  line-height: 1.8;
  color: var(--steel);
}

.page-about .about-cta {
  margin-top: clamp(22px, 3.2vw, 36px);
  padding: clamp(22px, 3.4vw, 38px);
  background: var(--cyan);
  color: var(--paper);
  display: grid;
  gap: 18px;
}

.page-about .about-cta__text {
  margin: 0;
  font-size: 16px;
  line-height: 1.85;
  color: var(--paper);
  max-width: 46em;
}

.page-about .about-cta__btn {
  justify-self: start;
  display: inline-block;
  padding: 12px 24px;
  background: var(--gold);
  color: var(--ink);
  font-family: var(--font-display);
  font-weight: 800;
  font-size: 15px;
  letter-spacing: 0.02em;
  text-decoration: none;
  transition: background 0.24s var(--ease);
}

.page-about .about-cta__btn:hover {
  background: #D8AC52;
}

/* ---------- 响应式 ---------- */
@media (min-width: 640px) {
  .page-about .about-hero__stats {
    grid-template-columns: repeat(4, minmax(0, 1fr));
  }

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

  .page-about .about-partners__item {
    grid-template-columns: 12em minmax(0, 1fr);
    gap: 20px;
    align-items: baseline;
  }
}

@media (min-width: 900px) {
  .page-about .about-hero__inner {
    grid-template-columns: minmax(0, 1.5fr) minmax(0, 1fr);
    align-items: end;
  }

  .page-about .about-hero__stats {
    border-top: 0;
    border-left: var(--about-hair);
    padding-top: 0;
    padding-left: 24px;
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }

  .page-about .about-chapter__head {
    grid-template-columns: 64px minmax(0, 1fr) 220px;
    align-items: start;
    gap: 0 24px;
  }

  .page-about .about-num {
    writing-mode: vertical-rl;
    text-orientation: mixed;
    font-size: 30px;
    letter-spacing: 0.22em;
    line-height: 1;
  }

  .page-about .about-chapter__note {
    grid-column: 3;
    text-align: right;
  }

  .page-about .about-chapter__body {
    grid-template-columns: minmax(0, 62fr) minmax(0, 34fr);
    gap: 4%;
    align-items: start;
  }

  .page-about .about-chapter__body--single {
    grid-template-columns: minmax(0, 62fr) minmax(0, 34fr);
  }

  .page-about .about-chapter__body--single .about-prose,
  .page-about .about-chapter__body--single .about-partners {
    grid-column: 1 / -1;
  }

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

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

  .page-about .about-team {
    grid-column: 1;
  }

  .page-about .about-team__figure {
    grid-column: 2;
    margin-top: 4px;
  }

  .page-about .about-cta {
    grid-template-columns: minmax(0, 1fr) auto;
    align-items: center;
    gap: 28px;
  }

  .page-about .about-cta__btn {
    justify-self: end;
  }

  /* 时间轴横向铺陈 */
  .page-about .about-timeline {
    grid-template-columns: repeat(4, minmax(0, 1fr));
    border-top: 1px solid var(--mist);
  }

  .page-about .about-timeline__item {
    padding: 34px 26px 0 0;
    border-left: 0;
    border-right: 1px solid var(--mist);
  }

  .page-about .about-timeline__item:last-child {
    border-right: 0;
    padding-right: 0;
  }

  .page-about .about-timeline__item::before {
    left: 0;
    top: -4.5px;
  }

  .page-about .about-timeline__sum {
    flex-direction: column;
    align-items: flex-start;
    gap: 6px;
  }

  .page-about .about-timeline__body {
    min-height: 96px;
  }
}

@media (min-width: 1100px) {
  .page-about .about-num {
    font-size: 34px;
  }

  .page-about .about-chapter__head {
    grid-template-columns: 74px minmax(0, 1fr) 240px;
  }
}

@media (prefers-reduced-motion: reduce) {
  .page-about .about-pillar,
  .page-about .about-next__card,
  .page-about .about-team__fill,
  .page-about .about-team__label,
  .page-about .about-cta__btn,
  .page-about .about-toc__link,
  .page-about .about-timeline__name,
  .page-about .about-fold__sum {
    transition: none;
  }
}