.page-about {
  --about-space: clamp(60px, 9vw, 128px);
  --about-rule: rgba(108, 130, 168, 0.3);
}

/* ---------- 首屏 ---------- */

.page-about .about-intro {
  padding-top: clamp(28px, 5vw, 52px);
  padding-bottom: clamp(48px, 7vw, 84px);
  max-width: 880px;
}

.page-about .about-intro .eyebrow {
  display: block;
  margin-bottom: 14px;
}

.page-about .about-intro h1 {
  font-family: var(--font-display);
  font-size: clamp(30px, 5vw, 56px);
  line-height: 1.06;
  letter-spacing: -0.02em;
  font-weight: 700;
  color: var(--mist-100);
  margin: 0 0 20px;
}

.page-about .about-intro__lead {
  font-size: clamp(16px, 1.6vw, 17px);
  line-height: 1.82;
  color: var(--steel-500);
  max-width: 62ch;
  margin: 0 0 34px;
}

.page-about .about-intro__facts {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 1px;
  background: var(--line-soft);
  border: 1px solid var(--line-soft);
  border-radius: var(--radius-md);
  overflow: hidden;
  margin: 0;
}

.page-about .about-intro__facts > div {
  background: var(--ds-900);
  padding: 16px 18px;
}

.page-about .about-intro__facts dt {
  font-size: 12px;
  letter-spacing: 0.08em;
  color: var(--steel-500);
  margin-bottom: 8px;
}

.page-about .about-intro__facts dd {
  margin: 0;
  font-family: var(--font-mono);
  font-variant-numeric: tabular-nums;
  font-size: 19px;
  letter-spacing: -0.01em;
  color: var(--mist-100);
}

/* ---------- 时间线 ---------- */

.page-about .about-timeline {
  position: relative;
  padding-top: var(--about-space);
  padding-bottom: var(--about-space);
  border-top: 1px solid var(--line-soft);
  overflow: hidden;
}

.page-about .timeline-bg {
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  height: 58%;
  z-index: 0;
  pointer-events: none;
  -webkit-mask-image: linear-gradient(180deg, rgba(0, 0, 0, 0.9), transparent 90%);
  mask-image: linear-gradient(180deg, rgba(0, 0, 0, 0.9), transparent 90%);
}

.page-about .timeline-bg img {
  display: block;
  width: 100%;
  height: 100%;
  object-fit: cover;
  opacity: 0.16;
  filter: saturate(0.7);
}

.page-about .about-timeline__inner {
  position: relative;
  z-index: 1;
}

.page-about .about-head {
  max-width: 660px;
  margin-bottom: clamp(38px, 5vw, 68px);
}

.page-about .about-head h2,
.page-about .about-rounds h2,
.page-about .about-next h2 {
  font-family: var(--font-display);
  font-size: clamp(24px, 3.6vw, 36px);
  line-height: 1.16;
  letter-spacing: -0.02em;
  font-weight: 700;
  color: var(--mist-100);
  margin: 0 0 14px;
}

.page-about .about-head__note {
  margin: 0;
  font-size: 15px;
  line-height: 1.78;
  color: var(--steel-500);
  max-width: 56ch;
}

.page-about .timeline {
  position: relative;
  list-style: none;
  margin: 0;
  padding: 0 0 0 22px;
}

.page-about .timeline::before {
  content: "";
  position: absolute;
  left: 4px;
  top: 10px;
  bottom: 10px;
  width: 1px;
  background: linear-gradient(
    180deg,
    rgba(242, 193, 78, 0.5),
    rgba(108, 130, 168, 0.22) 60%,
    rgba(255, 106, 31, 0.45)
  );
}

.page-about .stage {
  position: relative;
}

.page-about .stage::before {
  content: "";
  position: absolute;
  left: -22px;
  top: 12px;
  width: 9px;
  height: 9px;
  border-radius: 50%;
  background: var(--gold);
  box-shadow: 0 0 0 4px rgba(242, 193, 78, 0.14);
}

.page-about .stage--now::before {
  background: var(--orange);
  box-shadow: 0 0 0 4px rgba(255, 106, 31, 0.2);
}

.page-about .stage + .stage {
  margin-top: clamp(48px, 7vw, 96px);
  padding-top: clamp(48px, 7vw, 96px);
  border-top: 1px solid var(--about-rule);
}

.page-about .stage__inner {
  display: grid;
  gap: 22px;
}

.page-about .stage__seq {
  margin: 0 0 10px;
  font-size: 12px;
  letter-spacing: 0.1em;
  color: var(--gold);
}

.page-about .stage__title {
  font-family: var(--font-display);
  font-size: clamp(20px, 2.6vw, 27px);
  line-height: 1.2;
  letter-spacing: -0.01em;
  font-weight: 700;
  color: var(--mist-100);
  margin: 0 0 10px;
}

.page-about .stage__lead {
  margin: 0;
  font-size: 15px;
  line-height: 1.78;
  color: var(--steel-500);
  max-width: 54ch;
}

.page-about .stage__stat {
  margin: 0;
  text-align: left;
}

.page-about .stage__value {
  display: block;
  font-size: clamp(44px, 8vw, 84px);
  line-height: 0.92;
  font-weight: 700;
  letter-spacing: -0.03em;
  color: var(--mist-100);
}

.page-about .stage--now .stage__value {
  color: var(--orange);
}

.page-about .stage__unit {
  display: block;
  margin-top: 10px;
  font-size: 12px;
  letter-spacing: 0.08em;
  color: var(--steel-500);
}

/* 阶段折叠记录 */

.page-about .stage__fold {
  margin-top: 18px;
  border: 1px solid var(--line-soft);
  border-radius: var(--radius-md);
  background: rgba(18, 32, 60, 0.42);
  overflow: hidden;
}

.page-about .stage__fold summary {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 12px;
  padding: 13px 16px;
  cursor: pointer;
  font-size: 13px;
  letter-spacing: 0.06em;
  color: var(--steel-500);
  list-style: none;
  transition: color 0.2s var(--ease);
}

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

.page-about .stage__fold summary::marker {
  content: "";
}

.page-about .stage__fold summary:hover {
  color: var(--mist-100);
}

.page-about .stage__fold summary:focus-visible {
  outline: 2px solid var(--cyan);
  outline-offset: -2px;
}

.page-about .stage__chev {
  flex: none;
  width: 8px;
  height: 8px;
  border-right: 1px solid currentColor;
  border-bottom: 1px solid currentColor;
  transform: rotate(45deg);
  transition: transform 0.24s var(--ease);
}

.page-about .stage__fold[open] .stage__chev {
  transform: rotate(-135deg);
}

.page-about .stage__panel {
  padding: 16px;
  border-top: 1px solid var(--line-soft);
}

.page-about .stage__list {
  margin: 0;
  padding: 0;
  list-style: none;
  display: grid;
  gap: 9px;
}

.page-about .stage__list li {
  position: relative;
  padding-left: 18px;
  font-size: 15px;
  line-height: 1.7;
  color: var(--mist-100);
}

.page-about .stage__list li::before {
  content: "";
  position: absolute;
  left: 0;
  top: 0.72em;
  width: 9px;
  height: 1px;
  background: var(--orange);
}

/* ---------- 编号体系（浅底） ---------- */

.page-about .about-numbering {
  padding-top: var(--about-space);
  padding-bottom: var(--about-space);
  border-top: 1px solid var(--line-soft);
  border-bottom: 1px solid var(--line-soft);
}

.page-about .numbering-grid {
  display: grid;
  gap: 32px;
}

.page-about .numbering-copy .eyebrow {
  display: block;
  margin-bottom: 12px;
  color: #5A6880;
}

.page-about .numbering-copy h2 {
  font-family: var(--font-display);
  font-size: clamp(24px, 3.4vw, 34px);
  line-height: 1.16;
  letter-spacing: -0.02em;
  font-weight: 700;
  color: var(--ink-900);
  margin: 0 0 18px;
}

.page-about .numbering-copy > p {
  margin: 0 0 20px;
  font-size: 15px;
  line-height: 1.8;
  color: #3F4B60;
  max-width: 58ch;
}

.page-about .numbering-list {
  margin: 0 0 22px;
  padding: 0;
  list-style: none;
  display: grid;
  gap: 11px;
}

.page-about .numbering-list li {
  position: relative;
  padding-left: 20px;
  font-size: 15px;
  line-height: 1.72;
  color: var(--ink-900);
}

.page-about .numbering-list li::before {
  content: "";
  position: absolute;
  left: 0;
  top: 0.68em;
  width: 10px;
  height: 1px;
  background: var(--orange-deep);
}

.page-about .numbering-note {
  margin: 0;
  padding: 14px 16px;
  border-left: 2px solid var(--orange);
  background: rgba(255, 106, 31, 0.07);
  font-size: 14px;
  line-height: 1.75;
  color: var(--ink-900);
  max-width: 58ch;
}

.page-about .numbering-figure {
  margin: 0;
}

.page-about .numbering-figure .media {
  border-radius: var(--radius-md);
  overflow: hidden;
  border: 1px solid rgba(16, 24, 38, 0.14);
}

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

.page-about .numbering-figure .media__caption {
  display: block;
  margin-top: 12px;
  font-size: 13px;
  line-height: 1.68;
  color: #56637A;
}

.page-about .number-band {
  list-style: none;
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
  margin: clamp(34px, 5vw, 58px) 0 0;
  padding: 18px;
  background: var(--ds-900);
  border: 1px solid var(--ds-700);
  border-radius: var(--radius-md);
}

.page-about .number-band__item {
  display: inline-flex;
  align-items: baseline;
  gap: 8px;
  padding: 7px 12px;
  border: 1px solid var(--line-soft);
  border-radius: var(--radius-pill);
  background: rgba(18, 32, 60, 0.6);
}

.page-about .number-band__code {
  font-size: 12px;
  letter-spacing: 0.06em;
  color: var(--cyan);
}

.page-about .number-band__name {
  font-size: 13px;
  color: var(--mist-100);
}

/* ---------- 内容团队 ---------- */

.page-about .about-team {
  padding-top: var(--about-space);
  padding-bottom: var(--about-space);
}

.page-about .team-grid {
  display: grid;
  gap: 32px;
}

.page-about .team-media .media {
  border-radius: var(--radius-md);
  overflow: hidden;
  border: 1px solid var(--line-soft);
}

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

.page-about .team-copy .eyebrow {
  display: block;
  margin-bottom: 12px;
}

.page-about .team-copy h2 {
  font-family: var(--font-display);
  font-size: clamp(23px, 3.2vw, 32px);
  line-height: 1.16;
  letter-spacing: -0.02em;
  font-weight: 700;
  color: var(--mist-100);
  margin: 0 0 16px;
}

.page-about .team-copy > p {
  margin: 0 0 20px;
  font-size: 15px;
  line-height: 1.8;
  color: var(--steel-500);
  max-width: 58ch;
}

.page-about .role-list {
  list-style: none;
  margin: 0 0 22px;
  padding: 0;
}

.page-about .role-list li {
  display: grid;
  grid-template-columns: 48px minmax(0, 1fr);
  gap: 4px 16px;
  align-items: baseline;
  padding: 16px 0;
  border-top: 1px solid var(--line-soft);
}

.page-about .role-list li:last-child {
  border-bottom: 1px solid var(--line-soft);
}

.page-about .role-list__num {
  grid-column: 1;
  grid-row: 1 / span 2;
  align-self: center;
  font-size: 26px;
  font-weight: 700;
  letter-spacing: -0.02em;
  color: var(--orange);
}

.page-about .role-list__name {
  grid-column: 2;
  grid-row: 1;
  font-size: 15px;
  font-weight: 600;
  color: var(--mist-100);
}

.page-about .role-list__desc {
  grid-column: 2;
  grid-row: 2;
  font-size: 14px;
  line-height: 1.7;
  color: var(--steel-500);
}

.page-about .team-note {
  margin: 0;
  padding-left: 16px;
  border-left: 1px solid var(--line-strong);
  font-size: 14px;
  line-height: 1.78;
  color: var(--steel-500);
  max-width: 58ch;
}

/* ---------- 轮次记录 ---------- */

.page-about .about-rounds {
  padding-top: var(--about-space);
  padding-bottom: var(--about-space);
  border-top: 1px solid var(--line-soft);
}

.page-about .rounds-grid {
  display: grid;
  gap: 24px;
}

.page-about .rounds-copy p {
  margin: 0 0 16px;
  font-size: 15px;
  line-height: 1.82;
  color: var(--steel-500);
  max-width: 60ch;
}

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

.page-about .rounds-copy a {
  color: var(--cyan);
  text-decoration: none;
  border-bottom: 1px solid rgba(41, 224, 214, 0.4);
  transition: border-color 0.2s var(--ease);
}

.page-about .rounds-copy a:hover {
  border-bottom-color: var(--cyan);
}

.page-about .rounds-copy a:focus-visible {
  outline: 2px solid var(--cyan);
  outline-offset: 2px;
}

/* ---------- 推进中的工作 ---------- */

.page-about .about-next {
  padding-top: var(--about-space);
  padding-bottom: var(--about-space);
  border-top: 1px solid var(--line-soft);
}

.page-about .about-next .eyebrow {
  display: block;
  margin-bottom: 12px;
}

.page-about .next-list {
  list-style: none;
  margin: clamp(30px, 4vw, 48px) 0 0;
  padding: 0;
}

.page-about .next-list__item {
  display: grid;
  grid-template-columns: 44px minmax(0, 1fr);
  gap: 6px 18px;
  padding: 26px 0;
  border-top: 1px solid var(--line-soft);
}

.page-about .next-list__idx {
  grid-column: 1;
  grid-row: 1;
  font-size: 13px;
  letter-spacing: 0.08em;
  color: var(--orange);
}

.page-about .next-list__item h3 {
  grid-column: 2;
  grid-row: 1;
  margin: 0;
  font-family: var(--font-display);
  font-size: 19px;
  line-height: 1.3;
  letter-spacing: -0.01em;
  color: var(--mist-100);
}

.page-about .next-list__item p {
  grid-column: 2;
  grid-row: 2;
  margin: 0;
  font-size: 14px;
  line-height: 1.76;
  color: var(--steel-500);
  max-width: 56ch;
}

/* ---------- 相关页面 ---------- */

.page-about .about-links {
  padding-top: clamp(40px, 6vw, 68px);
  padding-bottom: clamp(56px, 8vw, 100px);
  border-top: 1px solid var(--line-soft);
}

.page-about .about-links__title {
  font-family: var(--font-body);
  font-size: 13px;
  font-weight: 500;
  letter-spacing: 0.08em;
  color: var(--steel-500);
  margin: 0 0 20px;
}

.page-about .about-links__list {
  list-style: none;
  margin: 0;
  padding: 0;
  display: grid;
  gap: 10px;
}

.page-about .about-links__list a {
  display: block;
  padding: 14px 16px;
  border: 1px solid var(--line-soft);
  border-radius: var(--radius-md);
  font-size: 15px;
  line-height: 1.5;
  color: var(--mist-100);
  text-decoration: none;
  transition: border-color 0.2s var(--ease), background 0.2s var(--ease);
}

.page-about .about-links__list a:hover {
  border-color: var(--line-strong);
  background: rgba(18, 32, 60, 0.55);
}

.page-about .about-links__list a:focus-visible {
  outline: 2px solid var(--cyan);
  outline-offset: 2px;
}

/* ---------- 响应式 ---------- */

@media (min-width: 720px) {
  .page-about .about-intro__facts {
    grid-template-columns: repeat(4, minmax(0, 1fr));
  }

  .page-about .about-links__list {
    grid-template-columns: repeat(2, minmax(0, 1fr));
    gap: 12px 24px;
  }
}

@media (min-width: 860px) {
  .page-about .stage__inner {
    grid-template-columns: minmax(0, 1fr) 200px;
    gap: 56px;
    align-items: start;
  }

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

  .page-about .next-list__item {
    grid-template-columns: 64px minmax(0, 1fr) minmax(0, 1.4fr);
    gap: 24px;
    align-items: baseline;
    padding: 28px 0;
  }

  .page-about .next-list__item h3 {
    grid-column: 2;
    grid-row: 1;
  }

  .page-about .next-list__item p {
    grid-column: 3;
    grid-row: 1;
  }
}

@media (min-width: 900px) {
  .page-about .numbering-grid {
    grid-template-columns: minmax(0, 1.25fr) minmax(0, 1fr);
    gap: 56px;
    align-items: start;
  }

  .page-about .team-grid {
    grid-template-columns: minmax(0, 0.92fr) minmax(0, 1.08fr);
    gap: 56px;
    align-items: start;
  }

  .page-about .rounds-grid {
    grid-template-columns: minmax(0, 0.8fr) minmax(0, 1.2fr);
    gap: 56px;
    align-items: start;
  }
}

@media (prefers-reduced-motion: reduce) {
  .page-about .stage__chev,
  .page-about .stage__fold summary,
  .page-about .rounds-copy a,
  .page-about .about-links__list a {
    transition: none;
  }
}