.page-about {
  --rail-w: 288px;
  background: var(--void);
  color: var(--silver);
}

.page-about h1,
.page-about h2,
.page-about h3 {
  font-family: var(--font-head);
  color: var(--silver);
}

.page-about h1 {
  margin: 14px 0 20px;
  font-size: clamp(2.1rem, 7vw, 4.4rem);
  line-height: 1.06;
  letter-spacing: -0.045em;
  font-weight: 900;
}

.page-about h2 {
  margin: 0 0 14px;
  font-size: clamp(1.5rem, 3.6vw, 2.4rem);
  line-height: 1.2;
  letter-spacing: -0.03em;
  font-weight: 900;
}

.page-about h3 {
  margin: 0 0 8px;
  font-size: 1.1rem;
  line-height: 1.35;
  letter-spacing: -0.01em;
  font-weight: 700;
}

.page-about p {
  margin: 0 0 12px;
  font-size: 0.97rem;
  line-height: 1.78;
  color: var(--silver-dim);
}

.page-about .section {
  border-top: 1px solid var(--line);
}

/* ---------- 首屏 ---------- */
.page-about .about-hero {
  position: relative;
  overflow: hidden;
  padding: clamp(26px, 6vw, 64px) 0 clamp(34px, 6vw, 76px);
  border-bottom: 1px solid var(--line);
}

.page-about .about-hero__bg {
  position: absolute;
  inset: 0;
  width: 100%;
  height: 100%;
  object-fit: cover;
  opacity: 0.26;
  filter: saturate(0.85);
}

.page-about .about-hero::after {
  content: "";
  position: absolute;
  inset: 0;
  background: linear-gradient(180deg, rgba(5, 7, 15, 0.55) 0%, rgba(5, 7, 15, 0.9) 62%, var(--void) 100%);
  pointer-events: none;
}

.page-about .about-hero__grid {
  position: relative;
  z-index: 1;
  display: grid;
  gap: clamp(26px, 5vw, 52px);
}

.page-about .about-hero__body .breadcrumb {
  margin-bottom: clamp(20px, 4vw, 34px);
}

.page-about .about-hero .lead {
  max-width: 62ch;
  color: var(--silver);
  font-size: clamp(1rem, 1.8vw, 1.1rem);
  line-height: 1.82;
}

.page-about .about-stats {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 1px;
  margin-top: clamp(22px, 4vw, 38px);
  border: 1px solid var(--line);
  background: var(--line);
}

.page-about .about-stat {
  display: flex;
  flex-direction: column;
  gap: 5px;
  padding: 14px 16px 16px;
  background: rgba(11, 18, 32, 0.78);
}

.page-about .about-stat__num {
  font-size: clamp(1.35rem, 3vw, 1.85rem);
  letter-spacing: -0.02em;
  color: var(--silver);
}

.page-about .about-stat__label {
  font-size: 0.79rem;
  letter-spacing: 0.02em;
  color: var(--silver-dim);
}

/* 年度刻度 */
.page-about .about-rail {
  border-top: 1px solid var(--line-2);
  padding-top: 14px;
}

.page-about .about-rail__caption {
  margin: 0 0 10px;
  font-size: 0.72rem;
  letter-spacing: 0.12em;
  text-transform: uppercase;
  color: var(--nebula);
}

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

.page-about .about-rail__item {
  position: relative;
  display: grid;
  grid-template-columns: 62px minmax(0, 1fr);
  gap: 10px;
  padding: 11px 8px 11px 16px;
  border-bottom: 1px solid var(--line);
  transition: background 0.16s var(--ease), border-color 0.16s var(--ease);
}

.page-about .about-rail__item::before {
  content: "";
  position: absolute;
  left: 0;
  top: 17px;
  width: 6px;
  height: 6px;
  background: var(--legacy);
  transition: background 0.16s var(--ease), transform 0.16s var(--ease);
}

.page-about .about-rail__item:hover {
  background: rgba(168, 139, 250, 0.08);
  border-bottom-color: var(--line-2);
}

.page-about .about-rail__item:hover::before {
  background: var(--nebula);
  transform: scale(1.35);
}

.page-about .about-rail__item:hover .about-rail__note {
  color: var(--silver);
}

.page-about .about-rail__year {
  font-size: 0.92rem;
  letter-spacing: 0.04em;
  color: var(--nebula);
}

.page-about .about-rail__note {
  font-size: 0.82rem;
  line-height: 1.6;
  color: var(--silver-dim);
  transition: color 0.16s var(--ease);
}

/* ---------- 章节头 ---------- */
.page-about .about-head__lead {
  max-width: 64ch;
  color: var(--silver-dim);
}

.page-about .about-head {
  margin-bottom: clamp(20px, 4vw, 34px);
}

/* ---------- 三条走向 ---------- */
.page-about .scope-tracks {
  border-top: 1px solid var(--line-2);
}

.page-about .scope-track {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 8px 24px;
  padding: 20px 0;
  border-bottom: 1px solid var(--line);
  transition: border-color 0.16s var(--ease);
}

.page-about .scope-track:hover {
  border-bottom-color: var(--line-2);
}

.page-about .scope-track__no {
  margin: 0;
  font-size: 0.78rem;
  letter-spacing: 0.1em;
  color: var(--legacy);
  transition: color 0.16s var(--ease);
}

.page-about .scope-track:hover .scope-track__no {
  color: var(--nebula);
}

.page-about .scope-track__body p {
  margin: 0;
  max-width: 68ch;
}

.page-about .scope-track__link {
  justify-self: start;
  align-self: start;
  font-size: 0.85rem;
  color: var(--silver);
  text-decoration: none;
  padding-bottom: 2px;
  border-bottom: 1px solid var(--line-2);
  transition: color 0.16s var(--ease), border-color 0.16s var(--ease);
}

.page-about .scope-track__link:hover {
  color: var(--nebula);
  border-bottom-color: var(--nebula);
}

/* ---------- 资料归档 ---------- */
.page-about .archive-layout {
  display: grid;
  gap: clamp(22px, 4vw, 44px);
}

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

.page-about .archive-figure {
  border-left: 2px solid var(--nebula);
  padding-left: 14px;
}

.page-about .archive-jump {
  display: flex;
  flex-wrap: wrap;
  gap: 4px 14px;
  align-items: baseline;
  margin: 0 0 16px;
  font-size: 0.74rem;
  letter-spacing: 0.06em;
  color: var(--silver-dim);
}

.page-about .archive-jump a {
  color: var(--silver);
  text-decoration: none;
  border-bottom: 1px solid var(--line-2);
  padding-bottom: 1px;
  transition: color 0.16s var(--ease), border-color 0.16s var(--ease);
}

.page-about .archive-jump a:hover {
  color: var(--nebula);
  border-bottom-color: var(--nebula);
}

.page-about .archive-ladder {
  list-style: none;
  margin: 0;
  padding: 0;
  border-top: 1px solid var(--line-2);
}

.page-about .archive-item {
  display: grid;
  grid-template-columns: 30px minmax(0, 1fr);
  gap: 6px 12px;
  padding: 16px 10px 16px 8px;
  border-bottom: 1px solid var(--line);
  border-left: 2px solid transparent;
  scroll-margin-top: 92px;
  transition: background 0.16s var(--ease), border-color 0.16s var(--ease);
}

.page-about .archive-item:hover {
  background: var(--panel);
  border-left-color: var(--nebula);
}

.page-about .archive-item__no {
  grid-column: 1;
  grid-row: 1;
  font-size: 0.74rem;
  letter-spacing: 0.08em;
  color: var(--legacy);
}

.page-about .archive-item__title {
  grid-column: 2;
  grid-row: 1;
  margin: 0;
}

.page-about .archive-item__text {
  grid-column: 2;
  grid-row: 2;
  margin: 0;
  font-size: 0.92rem;
  line-height: 1.72;
}

.page-about .archive-item .tag {
  grid-column: 2;
  grid-row: 3;
  justify-self: start;
  align-self: center;
  margin-top: 4px;
}

/* ---------- 团队与节奏 ---------- */
.page-about .about-team__grid {
  display: grid;
  gap: clamp(24px, 4vw, 48px);
}

.page-about .about-team__main > p {
  max-width: 58ch;
}

.page-about .team-list {
  list-style: none;
  margin: 20px 0 0;
  padding: 0;
  border-top: 1px solid var(--line);
}

.page-about .team-list li {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 3px;
  padding: 12px 0;
  border-bottom: 1px solid var(--line);
}

.page-about .team-list__key {
  font-size: 0.74rem;
  letter-spacing: 0.08em;
  color: var(--nebula);
}

.page-about .team-list__val {
  font-size: 0.9rem;
  line-height: 1.6;
  color: var(--silver);
}

.page-about .rhythm {
  margin-top: 20px;
  border: 1px solid var(--line-2);
  background: var(--panel);
  padding: 16px 16px 18px;
}

.page-about .rhythm__title {
  margin: 0 0 10px;
  font-size: 0.72rem;
  letter-spacing: 0.12em;
  text-transform: uppercase;
  color: var(--orange);
}

.page-about .rhythm__list {
  margin: 0;
  display: grid;
  gap: 0;
}

.page-about .rhythm__list > div {
  display: grid;
  grid-template-columns: 60px minmax(0, 1fr);
  gap: 10px;
  padding: 9px 0;
  border-top: 1px solid var(--line);
}

.page-about .rhythm__list dt {
  font-family: var(--font-mono);
  font-size: 0.73rem;
  letter-spacing: 0.06em;
  color: var(--silver-dim);
}

.page-about .rhythm__list dd {
  margin: 0;
  font-size: 0.87rem;
  line-height: 1.6;
  color: var(--silver);
}

/* ---------- 旧版迁移 ---------- */
.page-about .legacy-grid {
  display: grid;
  gap: clamp(22px, 4vw, 40px);
}

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

.page-about .legacy-steps li {
  position: relative;
  padding: 0 0 22px 20px;
  border-left: 1px solid var(--line-2);
}

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

.page-about .legacy-steps li::before {
  content: "";
  position: absolute;
  left: -4px;
  top: 6px;
  width: 7px;
  height: 7px;
  background: var(--legacy);
}

.page-about .legacy-steps li:last-child::before {
  background: var(--orange);
}

.page-about .legacy-steps h3 {
  font-size: 1rem;
}

.page-about .legacy-steps p {
  margin: 0;
  max-width: 52ch;
  font-size: 0.92rem;
}

.page-about .legacy-drawer {
  border: 1px solid var(--line-2);
  background: var(--deep);
  align-self: start;
}

.page-about .legacy-drawer summary {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 12px;
  padding: 14px 16px;
  font-size: 0.9rem;
  font-weight: 600;
  color: var(--silver);
  cursor: pointer;
  list-style: none;
}

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

.page-about .legacy-drawer summary::after {
  content: "+";
  font-family: var(--font-mono);
  font-size: 1rem;
  color: var(--legacy);
}

.page-about .legacy-drawer[open] summary::after {
  content: "−";
  color: var(--nebula);
}

.page-about .legacy-drawer summary:hover {
  background: var(--panel);
}

.page-about .legacy-drawer__list {
  list-style: none;
  margin: 0;
  padding: 0 16px;
  border-top: 1px solid var(--line);
}

.page-about .legacy-drawer__list li {
  display: flex;
  align-items: center;
  gap: 12px;
  padding: 10px 0;
  border-bottom: 1px solid var(--line);
  font-size: 0.89rem;
  color: var(--silver);
}

.page-about .legacy-drawer__list .mono {
  font-size: 0.72rem;
  letter-spacing: 0.08em;
  color: var(--silver-dim);
}

.page-about .legacy-drawer .note {
  margin: 0;
  padding: 12px 16px 16px;
  font-size: 0.76rem;
  line-height: 1.7;
  color: var(--silver-dim);
}

.page-about .legacy-help {
  margin-top: clamp(20px, 3vw, 30px);
  padding-top: 14px;
  border-top: 1px solid var(--line);
  font-size: 0.86rem;
  color: var(--silver-dim);
}

.page-about .legacy-help a {
  color: var(--nebula);
  text-decoration: none;
  border-bottom: 1px solid rgba(168, 139, 250, 0.45);
}

.page-about .legacy-help a:hover {
  color: var(--silver);
  border-bottom-color: var(--silver);
}

/* ---------- 收尾 ---------- */
.page-about .about-cta {
  background: var(--deep);
}

.page-about .about-cta__inner {
  display: grid;
  gap: 6px;
}

.page-about .about-cta__links {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
  margin-top: 14px;
}

.page-about .about-cta .btn {
  text-decoration: none;
}

/* ---------- 断点 ---------- */
@media (min-width: 600px) {
  .page-about .about-stats {
    grid-template-columns: repeat(3, minmax(0, 1fr));
  }

  .page-about .team-list li {
    grid-template-columns: 110px minmax(0, 1fr);
    align-items: baseline;
    gap: 14px;
  }
}

@media (min-width: 780px) {
  .page-about .scope-track {
    grid-template-columns: 56px minmax(0, 1fr) 160px;
    align-items: start;
    padding: 24px 0;
  }

  .page-about .scope-track__link {
    justify-self: end;
    margin-top: 4px;
  }
}

@media (min-width: 900px) {
  .page-about .about-hero__grid {
    grid-template-columns: var(--rail-w) minmax(0, 1fr);
    align-items: start;
  }

  .page-about .about-rail {
    order: -1;
    border-top: none;
    border-left: 1px solid var(--line-2);
    padding-top: 0;
    padding-left: 18px;
  }

  .page-about .about-rail__caption {
    margin-bottom: 12px;
  }

  .page-about .about-team__grid {
    grid-template-columns: minmax(0, 1.1fr) minmax(0, 0.9fr);
    align-items: start;
  }

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

@media (min-width: 960px) {
  .page-about .archive-layout {
    grid-template-columns: minmax(0, 5fr) minmax(0, 7fr);
    align-items: start;
  }

  .page-about .archive-item {
    grid-template-columns: 42px minmax(0, 1fr) auto;
    align-items: start;
    padding: 18px 16px 18px 10px;
  }

  .page-about .archive-item__no {
    grid-column: 1;
    grid-row: 1 / span 2;
  }

  .page-about .archive-item__title {
    grid-column: 2;
    grid-row: 1;
  }

  .page-about .archive-item__text {
    grid-column: 2;
    grid-row: 2;
  }

  .page-about .archive-item .tag {
    grid-column: 3;
    grid-row: 1 / span 2;
    align-self: center;
    margin-top: 0;
  }

  .page-about .archive-item:nth-child(2) {
    width: 96%;
  }

  .page-about .archive-item:nth-child(3) {
    width: 92%;
  }

  .page-about .archive-item:nth-child(4) {
    width: 97%;
  }

  .page-about .archive-item:nth-child(5) {
    width: 94%;
  }
}
<<<END>>>