.page-about {
  background: var(--paper-050);
}

/* ---------- 首屏 ---------- */
.page-about .about-hero {
  position: relative;
  overflow: hidden;
  background: var(--paper-050);
  border-bottom: var(--line);
}

.page-about .about-hero::before {
  content: "";
  position: absolute;
  inset: 0;
  background-image:
    repeating-linear-gradient(to right, var(--grid-line) 0, var(--grid-line) 1px, transparent 1px, transparent 96px),
    repeating-linear-gradient(to bottom, var(--grid-line) 0, var(--grid-line) 1px, transparent 1px, transparent 96px);
  opacity: .35;
  pointer-events: none;
}

.page-about .about-hero-inner {
  position: relative;
  z-index: 1;
  display: grid;
  gap: 34px;
  padding-block: clamp(36px, 6vw, 84px);
}

.page-about .about-title {
  margin: 14px 0 0;
  font-family: var(--font-display);
  font-weight: 700;
  font-size: clamp(32px, 5.6vw, var(--fs-2xl));
  line-height: 1.12;
  letter-spacing: -0.02em;
  color: var(--ink-900);
  max-width: 17ch;
}

.page-about .about-title em {
  font-style: normal;
  color: var(--brass-500);
}

.page-about .about-lede {
  margin: 20px 0 0;
  max-width: 46ch;
  font-size: var(--fs-base);
  line-height: 1.85;
  color: var(--muted-600);
}

.page-about .about-hero-actions {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
  margin-top: 28px;
}

.page-about .about-hero-frame {
  margin: 0;
}

/* ---------- 页内索引条 ---------- */
.page-about .about-jump {
  background: var(--paper-100);
  border-bottom: var(--line);
}

.page-about .about-jump-inner {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 6px 18px;
  padding-block: 13px;
}

.page-about .about-jump-label {
  font-family: var(--font-mono);
  font-size: var(--fs-xs);
  letter-spacing: .16em;
  text-transform: uppercase;
  color: var(--brass-700);
}

.page-about .about-jump-inner a {
  font-size: var(--fs-sm);
  color: var(--ink-green-600);
  text-decoration: none;
  padding-bottom: 2px;
  border-bottom: 1px solid transparent;
  transition: color .2s var(--ease), border-color .2s var(--ease);
}

.page-about .about-jump-inner a:hover,
.page-about .about-jump-inner a:focus-visible {
  color: var(--brass-700);
  border-bottom-color: var(--brass-500);
}

/* ---------- 通用左右分置 ---------- */
.page-about .about-split {
  display: grid;
  gap: 26px;
}

.page-about .about-rail {
  border-top: 2px solid var(--brass-500);
  padding-top: 14px;
}

.page-about .about-rail-num {
  margin: 0;
  font-family: var(--font-mono);
  font-size: var(--fs-xl);
  font-weight: 300;
  line-height: 1;
  letter-spacing: -.02em;
  color: var(--brass-500);
}

.page-about .about-rail .kicker {
  margin-top: 10px;
}

.page-about .about-rail-note {
  margin: 12px 0 0;
  max-width: 26ch;
  font-size: var(--fs-sm);
  line-height: 1.75;
  color: var(--muted-600);
}

.page-about .about-body > .h2 {
  margin-top: 0;
}

.page-about .about-body p {
  margin: 18px 0 0;
  font-size: var(--fs-base);
  line-height: 1.85;
  color: var(--ink-900);
}

.page-about .about-body p strong {
  color: var(--brass-700);
  font-weight: 600;
}

.page-about .about-inline-link {
  font-size: var(--fs-sm);
  color: var(--muted-600);
}

.page-about .about-inline-link a {
  color: var(--ink-green-600);
  text-decoration: underline;
  text-underline-offset: 3px;
  text-decoration-color: var(--brass-500);
}

.page-about .about-inline-link a:hover {
  color: var(--brass-700);
}

/* ---------- 区块标题 ---------- */
.page-about .about-section-head {
  max-width: 60ch;
  margin-bottom: clamp(26px, 4vw, 48px);
}

.page-about .about-section-head .h2 {
  margin-top: 10px;
}

.page-about .about-section-head .lede {
  margin-top: 16px;
  color: var(--muted-600);
  line-height: 1.8;
}

/* ---------- 版本时间轴 ---------- */
.page-about .about-versions-grid {
  display: grid;
  gap: 34px;
}

.page-about .about-timeline-list {
  display: grid;
  gap: 0;
}

.page-about .about-tl-item {
  position: relative;
  padding-left: 30px;
  border-top: var(--line);
}

.page-about .about-tl-item:last-child {
  border-bottom: var(--line);
}

.page-about .about-tl-item::before {
  content: "";
  position: absolute;
  left: 8px;
  top: 0;
  bottom: 0;
  width: 1px;
  background: var(--grid-line);
  z-index: 0;
}

.page-about .about-tl-item::after {
  content: "";
  position: absolute;
  left: 4px;
  top: 24px;
  width: 9px;
  height: 9px;
  border-radius: 50%;
  background: var(--brass-500);
  box-shadow: 0 0 0 4px var(--paper-100);
  z-index: 1;
}

.page-about .about-tl-trigger {
  position: relative;
  z-index: 1;
  display: flex;
  align-items: baseline;
  flex-wrap: wrap;
  gap: 4px 14px;
  width: 100%;
  padding: 20px 0;
  background: none;
  border: 0;
  text-align: left;
  font: inherit;
  color: inherit;
  cursor: pointer;
}

.page-about .about-tl-ver {
  flex: 0 0 auto;
  font-family: var(--font-mono);
  font-size: clamp(20px, 3vw, var(--fs-lg));
  font-weight: 700;
  line-height: 1;
  letter-spacing: .02em;
  color: var(--brass-500);
}

.page-about .about-tl-main {
  flex: 1 1 15ch;
  min-width: 0;
}

.page-about .about-tl-title {
  display: block;
  font-family: var(--font-display);
  font-size: var(--fs-md);
  font-weight: 600;
  line-height: 1.4;
  color: var(--ink-900);
}

.page-about .about-tl-meta {
  display: block;
  margin-top: 5px;
  font-family: var(--font-mono);
  font-size: var(--fs-xs);
  letter-spacing: .1em;
  color: var(--muted-600);
}

.page-about .about-tl-trigger .accordion-icon {
  flex: 0 0 auto;
  margin-left: auto;
  align-self: center;
}

.page-about .about-tl-panel ul {
  margin: 0 0 20px;
  padding-left: 18px;
  display: grid;
  gap: 10px;
}

.page-about .about-tl-panel li {
  font-size: var(--fs-sm);
  line-height: 1.8;
  color: var(--ink-900);
}

.page-about .about-versions-aside {
  display: grid;
  gap: 22px;
  align-content: start;
}

.page-about .about-versions-aside .img-frame {
  margin: 0;
}

.page-about .about-stat {
  border-left: 2px solid var(--brass-500);
  padding-left: 16px;
}

.page-about .about-stat-num {
  display: block;
  font-family: var(--font-display);
  font-size: var(--fs-xl);
  font-weight: 700;
  line-height: 1;
  color: var(--brass-700);
}

.page-about .about-stat-label {
  display: block;
  margin-top: 8px;
  font-size: var(--fs-sm);
  line-height: 1.7;
  color: var(--muted-600);
}

.page-about .about-aside-note {
  margin: 0;
  font-size: var(--fs-sm);
  line-height: 1.8;
  color: var(--muted-600);
}

.page-about .about-aside-note a {
  color: var(--ink-green-600);
  text-decoration: underline;
  text-underline-offset: 3px;
  text-decoration-color: var(--brass-500);
}

/* ---------- 团队 ---------- */
.page-about .about-team-figure {
  margin: 0 0 clamp(28px, 4vw, 48px);
}

.page-about .about-team-grid {
  display: grid;
  gap: 18px;
}

.page-about .about-team-card {
  background: var(--paper-100);
  padding: 24px 22px 18px;
}

.page-about .about-team-code {
  margin: 0;
  font-family: var(--font-mono);
  font-size: var(--fs-xs);
  letter-spacing: .16em;
  color: var(--brass-700);
}

.page-about .about-team-card h3 {
  margin: 10px 0 0;
  font-family: var(--font-display);
  font-size: var(--fs-lg);
  font-weight: 600;
  line-height: 1.3;
  color: var(--ink-900);
}

.page-about .about-team-card > p {
  margin: 12px 0 0;
  font-size: var(--fs-sm);
  line-height: 1.8;
  color: var(--muted-600);
}

.page-about .about-team-card .accordion {
  margin-top: 16px;
  border-top: var(--line);
}

.page-about .about-team-trigger {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 12px;
  width: 100%;
  padding: 14px 0;
  background: none;
  border: 0;
  text-align: left;
  font: inherit;
  font-size: var(--fs-sm);
  color: var(--ink-green-600);
  cursor: pointer;
}

.page-about .about-team-panel ul {
  margin: 0 0 16px;
  padding-left: 18px;
  display: grid;
  gap: 8px;
}

.page-about .about-team-panel li {
  font-size: var(--fs-sm);
  line-height: 1.8;
  color: var(--ink-900);
}

/* ---------- 长期机制（深底） ---------- */
.page-about .about-keep {
  background: var(--ink-green-900);
}

.page-about .about-keep-head {
  max-width: 58ch;
}

.page-about .about-keep-kicker {
  color: var(--gold-tint);
}

.page-about .about-keep .h2 {
  margin-top: 10px;
  color: var(--paper-050);
}

.page-about .about-keep-lede {
  margin: 16px 0 0;
  font-size: var(--fs-base);
  line-height: 1.85;
  color: var(--gold-tint);
}

.page-about .about-keep-list {
  margin-top: clamp(26px, 4vw, 44px);
}

.page-about .about-keep-row {
  padding: 22px 0;
  border-top: 1px solid var(--ink-green-600);
  border-bottom: 1px solid var(--ink-green-600);
}

.page-about .about-keep-row + .about-keep-row {
  border-top: 0;
}

.page-about .about-keep-code {
  font-family: var(--font-mono);
  font-size: var(--fs-xs);
  letter-spacing: .14em;
  color: var(--gold-tint);
}

.page-about .about-keep-item-title {
  margin: 0 0 8px;
  font-family: var(--font-display);
  font-size: var(--fs-md);
  font-weight: 600;
  line-height: 1.4;
  color: var(--paper-050);
}

.page-about .about-keep-item-text {
  margin: 0;
  font-size: var(--fs-sm);
  line-height: 1.85;
  color: var(--gold-tint);
}

.page-about .about-keep-meta {
  font-family: var(--font-mono);
  font-size: var(--fs-xs);
  letter-spacing: .1em;
  color: var(--brass-500);
}

.page-about .about-keep-more {
  display: inline-block;
  margin-top: 26px;
  padding-bottom: 4px;
  font-family: var(--font-mono);
  font-size: var(--fs-sm);
  letter-spacing: .08em;
  color: var(--gold-tint);
  text-decoration: none;
  border-bottom: 1px solid var(--brass-500);
  transition: color .2s var(--ease);
}

.page-about .about-keep-more:hover,
.page-about .about-keep-more:focus-visible {
  color: var(--paper-050);
}

/* ---------- 适配流程 ---------- */
.page-about .about-flow {
  list-style: none;
  margin: 26px 0 0;
  padding: 0;
  border-top: var(--line);
}

.page-about .about-flow-step {
  display: grid;
  gap: 8px;
  padding: 22px 0;
  border-bottom: var(--line);
}

.page-about .about-flow-num {
  font-family: var(--font-mono);
  font-size: var(--fs-md);
  line-height: 1.2;
  color: var(--brass-500);
}

.page-about .about-flow-title {
  margin: 0;
  font-family: var(--font-display);
  font-size: var(--fs-md);
  font-weight: 600;
  line-height: 1.4;
  color: var(--ink-900);
}

.page-about .about-flow-step p {
  margin: 8px 0 0;
  font-size: var(--fs-sm);
  line-height: 1.85;
  color: var(--muted-600);
}

/* ---------- 下一步 ---------- */
.page-about .about-next-inner {
  display: grid;
  gap: 26px;
  padding-block: clamp(34px, 5vw, 64px);
  align-items: center;
}

.page-about .about-next-inner .h2 {
  margin-top: 10px;
}

.page-about .about-next-text {
  margin: 14px 0 0;
  max-width: 52ch;
  font-size: var(--fs-base);
  line-height: 1.85;
  color: var(--muted-600);
}

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

/* ---------- 桌面栅格 ---------- */
@media (min-width: 760px) {
  .page-about .about-flow-step {
    grid-template-columns: 72px minmax(0, 1fr);
    gap: 24px;
    align-items: start;
  }
}

@media (min-width: 900px) {
  .page-about .about-hero-inner {
    grid-template-columns: minmax(0, 7fr) minmax(0, 5fr);
    gap: clamp(32px, 5vw, 72px);
    align-items: end;
  }

  .page-about .about-split {
    grid-template-columns: minmax(0, 4fr) minmax(0, 8fr);
    gap: clamp(32px, 6vw, 88px);
    align-items: start;
  }

  .page-about .about-team-grid {
    grid-template-columns: repeat(3, minmax(0, 1fr));
    gap: 22px;
    align-items: start;
  }

  .page-about .about-team-card:nth-child(2) {
    margin-top: 34px;
  }

  .page-about .about-team-card:nth-child(3) {
    margin-top: 68px;
  }

  .page-about .about-next-inner {
    grid-template-columns: minmax(0, 1fr) auto;
    gap: 40px;
  }
}

@media (min-width: 980px) {
  .page-about .about-versions-grid {
    grid-template-columns: minmax(0, 7fr) minmax(0, 4fr);
    gap: clamp(32px, 5vw, 68px);
    align-items: start;
  }

  .page-about .about-tl-trigger {
    padding: 24px 0;
  }

  .page-about .about-tl-item {
    padding-left: 34px;
  }
}

@media (prefers-reduced-motion: reduce) {
  .page-about .about-jump-inner a,
  .page-about .about-keep-more {
    transition: none;
  }
}
<<<END>>>