.page-about {
  --about-pad: clamp(46px, 8vw, 104px);
  --about-stripe: linear-gradient(90deg, var(--orange) 0 36%, var(--cyan) 36% 70%, var(--blue) 70% 100%);
  background: var(--bg);
  color: var(--fg);
  overflow-x: hidden;
}

/* ---------- 面包屑 ---------- */
.page-about .breadcrumbs {
  padding-top: clamp(14px, 2.6vw, 26px);
}
.page-about .breadcrumbs ol {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 8px;
  margin: 0;
  padding: 0;
  list-style: none;
  font-size: var(--fs-12);
  letter-spacing: .08em;
}
.page-about .breadcrumbs a {
  color: var(--accent-2);
  text-decoration: none;
}
.page-about .breadcrumbs a:hover {
  text-decoration: underline;
}
.page-about .breadcrumbs li + li::before {
  content: "/";
  margin-right: 8px;
  color: var(--graphite);
}
.page-about .breadcrumbs [aria-current="page"] {
  color: var(--fg-dim);
}

/* ---------- 卷首 ---------- */
.page-about .about-hero {
  position: relative;
  padding-block: clamp(34px, 6.5vw, 84px) clamp(38px, 7vw, 92px);
  background:
    radial-gradient(120% 100% at 100% 0%, rgba(34, 227, 195, .15), transparent 58%),
    radial-gradient(95% 90% at 0% 100%, rgba(255, 106, 26, .13), transparent 60%),
    var(--ink-900);
  border-bottom: 2px solid var(--ink-700);
}
.page-about .about-hero::before {
  content: "";
  position: absolute;
  inset: 0 0 auto 0;
  height: 6px;
  background: var(--about-stripe);
}
.page-about .about-hero::after {
  content: "";
  position: absolute;
  right: -60px;
  top: 22%;
  width: 220px;
  height: 220px;
  border: 2px solid rgba(61, 123, 255, .28);
  transform: rotate(18deg);
  pointer-events: none;
}

.page-about .about-hero-grid {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: clamp(26px, 5vw, 54px);
}

.page-about .about-kicker {
  margin: 0 0 16px;
  font-family: var(--font-mono);
  font-size: var(--fs-12);
  letter-spacing: .2em;
  text-transform: uppercase;
  color: var(--accent-2);
}

.page-about .about-title {
  margin: 0 0 20px;
  font-family: var(--font-serif);
  font-weight: 700;
  font-size: clamp(34px, 6vw, var(--fs-64));
  line-height: 1.1;
  color: var(--paper);
}

.page-about .about-lede {
  max-width: 60ch;
  margin: 0 0 16px;
  font-size: var(--fs-16);
  line-height: 1.8;
  color: rgba(247, 249, 252, .84);
}

.page-about .about-actions {
  display: flex;
  flex-wrap: wrap;
  gap: 14px;
  margin-top: 28px;
}
.page-about .about-actions .btn {
  text-decoration: none;
}

.page-about .about-hero-panel {
  align-self: start;
  padding: clamp(20px, 3vw, 28px);
  background: var(--ink-800);
  border: 2px solid var(--ink-700);
  border-top: 4px solid var(--accent);
  box-shadow: var(--shadow-soft);
}
.page-about .about-panel-list {
  margin: 0;
}
.page-about .about-panel-list > div {
  display: flex;
  justify-content: space-between;
  align-items: baseline;
  gap: 14px;
  padding: 11px 0;
  border-bottom: var(--hair);
}
.page-about .about-panel-list > div:last-child {
  border-bottom: 0;
}
.page-about .about-panel-list dt {
  font-size: var(--fs-14);
  color: var(--fg-dim);
}
.page-about .about-panel-list dd {
  margin: 0;
  font-size: var(--fs-16);
  color: var(--paper);
}
.page-about .about-panel-list > div:first-child dd {
  color: var(--accent);
  font-size: var(--fs-20);
}
.page-about .about-panel-note {
  margin: 18px 0 0;
  padding-top: 16px;
  border-top: var(--hair);
  font-size: var(--fs-14);
  line-height: 1.7;
  color: var(--fg-dim);
}

/* ---------- 目录条 ---------- */
.page-about .about-toc {
  position: sticky;
  top: 0;
  z-index: 30;
  background: rgba(7, 12, 28, .95);
  border-bottom: 2px solid var(--ink-700);
}
.page-about .about-toc-inner {
  display: flex;
  align-items: center;
  gap: 16px;
  padding-block: 11px;
  overflow-x: auto;
  scrollbar-width: none;
}
.page-about .about-toc-inner::-webkit-scrollbar {
  display: none;
}
.page-about .about-toc-label {
  flex: none;
  font-size: var(--fs-12);
  letter-spacing: .16em;
  color: var(--graphite);
}
.page-about .about-toc-list {
  display: flex;
  gap: 8px;
  margin: 0;
  padding: 0;
  list-style: none;
}
.page-about .about-toc-list a {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 7px 12px;
  border: 1px solid rgba(154, 166, 191, .3);
  color: var(--fg);
  font-size: var(--fs-14);
  white-space: nowrap;
  text-decoration: none;
  transition: border-color .18s var(--ease), color .18s var(--ease), background-color .18s var(--ease);
}
.page-about .about-toc-list a:hover,
.page-about .about-toc-list a:focus-visible {
  border-color: var(--accent-2);
  color: var(--accent-2);
  background: rgba(34, 227, 195, .08);
}
.page-about .about-toc-list .mono {
  color: var(--accent);
  font-size: var(--fs-12);
}

/* ---------- 区段骨架 ---------- */
.page-about .about-section {
  padding-block: var(--about-pad);
  scroll-margin-top: 72px;
  border-top: 2px solid var(--ink-700);
}
.page-about .about-section--alt {
  background: var(--ink-700);
}
.page-about .about-section--deep {
  background: var(--ink-900);
}

.page-about .section-head {
  margin-bottom: clamp(26px, 4.5vw, 46px);
}
.page-about .about-head-meta {
  display: flex;
  align-items: center;
  gap: 12px;
  margin: 0 0 12px;
}
.page-about .section-num {
  font-size: var(--fs-14);
  letter-spacing: .08em;
  color: var(--accent);
}
.page-about .section-label {
  font-family: var(--font-sans);
  font-size: var(--fs-12);
  font-weight: 700;
  letter-spacing: .18em;
  color: var(--accent-2);
}
.page-about .section-title {
  margin: 0;
  font-family: var(--font-serif);
  font-weight: 700;
  font-size: clamp(26px, 4.2vw, var(--fs-40));
  line-height: 1.24;
  color: var(--paper);
}
.page-about .section-desc {
  max-width: 62ch;
  margin: 14px 0 0;
  font-size: var(--fs-16);
  line-height: 1.75;
  color: var(--fg-dim);
}

/* ---------- 正文 ---------- */
.page-about .about-prose {
  max-width: 68ch;
}
.page-about .about-prose--wide {
  max-width: 78ch;
  margin-bottom: clamp(26px, 4vw, 40px);
}
.page-about .about-prose p {
  margin: 0 0 18px;
  font-size: var(--fs-16);
  line-height: 1.82;
  color: rgba(247, 249, 252, .85);
}
.page-about .about-prose p:last-child {
  margin-bottom: 0;
}
.page-about .about-prose a {
  color: var(--accent-2);
  text-decoration: none;
  border-bottom: 1px solid rgba(34, 227, 195, .42);
  transition: border-color .18s var(--ease), color .18s var(--ease);
}
.page-about .about-prose a:hover {
  border-bottom-color: var(--accent-2);
}

.page-about .about-figure {
  margin: 0 0 clamp(26px, 4vw, 40px);
}
.page-about .about-figure--side {
  margin: 0;
}
.page-about .about-figure img {
  display: block;
  width: 100%;
  height: auto;
  object-fit: cover;
}

/* ---------- 01 来路与定位 ---------- */
.page-about .about-split {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: clamp(26px, 4vw, 46px);
}

.page-about .about-rail {
  align-self: start;
  padding-left: 20px;
  border-left: 3px solid var(--accent);
}
.page-about .about-rail-title {
  margin: 0 0 14px;
  font-family: var(--font-sans);
  font-size: var(--fs-14);
  font-weight: 700;
  letter-spacing: .12em;
  color: var(--paper);
}
.page-about .about-versions {
  margin: 0;
  padding: 0;
  list-style: none;
}
.page-about .about-versions li {
  display: flex;
  align-items: baseline;
  gap: 14px;
  padding: 11px 0;
  border-bottom: var(--hair);
}
.page-about .about-versions .mono {
  flex: none;
  min-width: 46px;
  font-size: var(--fs-14);
  color: var(--accent-2);
}
.page-about .about-versions em {
  font-style: normal;
  font-size: var(--fs-14);
  color: var(--fg-dim);
}
.page-about .about-rail-note {
  margin: 16px 0 0;
  font-size: var(--fs-14);
  line-height: 1.72;
  color: var(--fg-dim);
}

/* ---------- 02 内容原则 ---------- */
.page-about .about-rules {
  margin: 0;
  padding: 0;
  list-style: none;
}
.page-about .about-rule {
  display: flex;
  gap: clamp(16px, 3vw, 26px);
  padding: clamp(20px, 3vw, 28px) clamp(4px, 1vw, 12px);
  border-top: 1px solid rgba(154, 166, 191, .26);
  transition: background-color .18s var(--ease);
}
.page-about .about-rule:last-child {
  border-bottom: 1px solid rgba(154, 166, 191, .26);
}
.page-about .about-rule:hover {
  background: rgba(34, 227, 195, .06);
}
.page-about .about-rule-num {
  flex: none;
  width: 34px;
  font-size: var(--fs-14);
  letter-spacing: .08em;
  color: var(--accent);
  padding-top: 4px;
}
.page-about .about-rule-body {
  min-width: 0;
}
.page-about .about-rule-title {
  margin: 0;
  font-family: var(--font-sans);
  font-size: var(--fs-20);
  font-weight: 700;
  line-height: 1.4;
  color: var(--paper);
}
.page-about .about-rule-text {
  max-width: 68ch;
  margin: 8px 0 0;
  font-size: var(--fs-16);
  line-height: 1.78;
  color: var(--fg-dim);
}

.page-about .about-quote {
  max-width: 40ch;
  margin: clamp(34px, 5vw, 56px) 0 0;
  padding: 6px 0 6px 22px;
  border-left: 3px solid var(--orange);
  font-family: var(--font-serif);
  font-size: clamp(20px, 3vw, var(--fs-28));
  line-height: 1.5;
  color: var(--paper);
}

/* ---------- 03 三层索引 ---------- */
.page-about .about-layers {
  position: relative;
  margin: 0;
  padding: 0;
  list-style: none;
  display: grid;
  gap: 18px;
}
.page-about .about-layer {
  position: relative;
  display: flex;
  align-items: flex-start;
  gap: clamp(14px, 2.6vw, 24px);
  padding: clamp(18px, 3vw, 26px);
  background: var(--ink-800);
  border: 2px solid var(--ink-700);
  transition: border-color .18s var(--ease), transform .18s var(--ease);
}
.page-about .about-layer:hover {
  border-color: var(--accent-2);
  transform: translateY(-2px);
}
.page-about .about-layer-num {
  flex: none;
  width: 48px;
  height: 48px;
  display: grid;
  place-items: center;
  border: 2px solid var(--accent);
  color: var(--accent);
  font-size: var(--fs-20);
  line-height: 1;
}
.page-about .about-layer-body {
  min-width: 0;
}
.page-about .about-layer-title {
  margin: 0;
  font-family: var(--font-sans);
  font-size: var(--fs-20);
  font-weight: 700;
  color: var(--paper);
}
.page-about .about-layer-text {
  max-width: 66ch;
  margin: 8px 0 0;
  font-size: var(--fs-16);
  line-height: 1.76;
  color: var(--fg-dim);
}
.page-about .about-layer:not(:last-child)::after {
  content: "";
  position: absolute;
  left: clamp(40px, 5vw, 46px);
  bottom: -18px;
  width: 2px;
  height: 18px;
  background: var(--accent-2);
  opacity: .75;
  transition: background-color .18s var(--ease), opacity .18s var(--ease);
}
.page-about .about-layer:hover::after {
  background: var(--orange);
  opacity: 1;
}

/* ---------- 04 批次节奏 ---------- */
.page-about .about-batch-grid {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: clamp(24px, 4vw, 44px);
  margin-bottom: clamp(30px, 5vw, 52px);
}

.page-about .about-timeline {
  margin: 0;
  padding: 0;
  list-style: none;
}
.page-about .about-tl-item {
  position: relative;
  padding-left: clamp(30px, 5vw, 46px);
  padding-bottom: clamp(24px, 4vw, 36px);
}
.page-about .about-tl-item:last-child {
  padding-bottom: 0;
}
.page-about .about-tl-item::before {
  content: "";
  position: absolute;
  left: 7px;
  top: 12px;
  bottom: 0;
  width: 2px;
  background: rgba(34, 227, 195, .32);
}
.page-about .about-tl-item:last-child::before {
  display: none;
}
.page-about .about-tl-item::after {
  content: "";
  position: absolute;
  left: 0;
  top: 6px;
  width: 16px;
  height: 16px;
  border-radius: 50%;
  background: var(--accent-2);
  box-shadow: 0 0 0 4px rgba(34, 227, 195, .16), 0 0 14px rgba(34, 227, 195, .45);
  transition: background-color .18s var(--ease), box-shadow .18s var(--ease);
}
.page-about .about-tl-item:hover::after {
  background: var(--accent);
  box-shadow: 0 0 0 5px rgba(255, 106, 26, .2), 0 0 18px rgba(255, 106, 26, .5);
}
.page-about .about-tl-title {
  margin: 0;
  font-family: var(--font-sans);
  font-size: var(--fs-20);
  font-weight: 700;
  line-height: 1.45;
  color: var(--paper);
}
.page-about .about-tl-title::before {
  content: "";
  display: inline-block;
  width: 16px;
  height: 2px;
  margin-right: 12px;
  vertical-align: middle;
  background: var(--accent);
}
.page-about .about-tl-text {
  max-width: 66ch;
  margin: 8px 0 0;
  font-size: var(--fs-16);
  line-height: 1.78;
  color: rgba(247, 249, 252, .84);
}
.page-about .about-tl-scope {
  margin: 10px 0 0;
  padding-left: 12px;
  border-left: 2px solid rgba(154, 166, 191, .3);
  font-family: var(--font-mono);
  font-size: var(--fs-14);
  line-height: 1.7;
  color: var(--fg-dim);
  transition: color .18s var(--ease), border-color .18s var(--ease);
}
.page-about .about-tl-item:hover .about-tl-scope {
  color: var(--accent-2);
  border-left-color: rgba(34, 227, 195, .6);
}

/* ---------- 05 编校分工 ---------- */
.page-about .about-team-grid {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: clamp(26px, 4vw, 48px);
}

.page-about .about-stats {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(140px, 1fr));
  gap: 12px;
  margin: 0 0 clamp(22px, 3.5vw, 32px);
}
.page-about .about-stat {
  padding: clamp(14px, 2.4vw, 20px);
  background: var(--ink-900);
  border: 2px solid var(--ink-700);
  border-bottom: 4px solid var(--accent);
}
.page-about .about-stat dt {
  margin-bottom: 10px;
  font-size: var(--fs-12);
  letter-spacing: .12em;
  color: var(--fg-dim);
}
.page-about .about-stat dd {
  display: flex;
  align-items: baseline;
  gap: 4px;
  margin: 0;
  font-family: var(--font-mono);
  font-size: var(--fs-28);
  line-height: 1;
  color: var(--accent);
  font-variant-numeric: tabular-nums;
}
.page-about .about-stat dd span {
  font-size: var(--fs-14);
  color: var(--fg-dim);
}

.page-about .about-flow {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 10px;
  margin-bottom: clamp(22px, 3.5vw, 30px);
}
.page-about .about-flow-step {
  padding: 16px 18px;
  background: var(--ink-800);
  border: 2px solid var(--ink-700);
  border-left: 4px solid var(--accent-2);
  transition: border-color .18s var(--ease), transform .18s var(--ease);
}
.page-about .about-flow-step:hover {
  border-color: var(--accent-2);
  transform: translateY(-2px);
}
.page-about .about-flow-step strong {
  display: block;
  font-size: var(--fs-14);
  letter-spacing: .14em;
  color: var(--accent-2);
}
.page-about .about-flow-step p {
  margin: 8px 0 0;
  font-size: var(--fs-14);
  line-height: 1.72;
  color: var(--fg-dim);
}

/* ---------- 06 范围边界 ---------- */
.page-about .about-scope-grid {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: clamp(18px, 3vw, 28px);
}
.page-about .about-scope {
  padding: clamp(22px, 3vw, 32px);
  background: var(--ink-800);
  border: 2px solid var(--ink-700);
}
.page-about .about-scope--in {
  border-top: 4px solid var(--accent-2);
}
.page-about .about-scope--out {
  border-top: 4px solid var(--accent);
}
.page-about .about-scope-title {
  margin: 0 0 16px;
  font-family: var(--font-serif);
  font-size: var(--fs-20);
  font-weight: 700;
  color: var(--paper);
}
.page-about .about-scope ul {
  display: grid;
  gap: 12px;
  margin: 0;
  padding: 0;
  list-style: none;
}
.page-about .about-scope li {
  position: relative;
  padding-left: 22px;
  font-size: var(--fs-16);
  line-height: 1.74;
  color: rgba(247, 249, 252, .84);
}
.page-about .about-scope li::before {
  content: "";
  position: absolute;
  left: 0;
  top: .68em;
  width: 10px;
  height: 2px;
  background: currentColor;
  opacity: .7;
}
.page-about .about-scope--in li::before {
  color: var(--accent-2);
  opacity: 1;
}
.page-about .about-scope--out li::before {
  color: var(--accent);
  opacity: 1;
}
.page-about .about-scope-note {
  max-width: 74ch;
  margin: clamp(24px, 4vw, 36px) 0 0;
  font-size: var(--fs-16);
  line-height: 1.78;
  color: var(--fg-dim);
}
.page-about .about-scope-note a,
.page-about .about-steps-note a,
.page-about .about-step p a {
  color: var(--accent-2);
  text-decoration: none;
  border-bottom: 1px solid rgba(34, 227, 195, .42);
  transition: border-color .18s var(--ease);
}
.page-about .about-scope-note a:hover,
.page-about .about-steps-note a:hover,
.page-about .about-step p a:hover {
  border-bottom-color: var(--accent-2);
}

/* ---------- 07 三步定位 ---------- */
.page-about .about-steps {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: clamp(16px, 3vw, 24px);
  margin: 0;
  padding: 0;
  list-style: none;
}
.page-about .about-step {
  padding: clamp(20px, 3vw, 28px);
  background: var(--ink-800);
  border: 2px solid var(--ink-700);
  transition: transform .18s var(--ease), border-color .18s var(--ease), box-shadow .18s var(--ease);
}
.page-about .about-step:hover {
  transform: translateY(-2px);
  border-color: var(--accent-2);
  box-shadow: var(--shadow-soft);
}
.page-about .about-step-num {
  display: inline-block;
  margin-bottom: 14px;
  padding-bottom: 4px;
  border-bottom: 2px solid var(--accent);
  font-size: var(--fs-12);
  letter-spacing: .18em;
  color: var(--accent);
}
.page-about .about-step h3 {
  margin: 0 0 10px;
  font-family: var(--font-sans);
  font-size: var(--fs-20);
  font-weight: 700;
  color: var(--paper);
}
.page-about .about-step p {
  margin: 0;
  font-size: var(--fs-16);
  line-height: 1.76;
  color: var(--fg-dim);
}
.page-about .about-steps-note {
  max-width: 74ch;
  margin: clamp(24px, 4vw, 36px) 0 0;
  font-size: var(--fs-14);
  line-height: 1.78;
  color: var(--fg-dim);
}

/* ---------- 响应式 ---------- */
@media (min-width: 700px) {
  .page-about .about-flow {
    grid-template-columns: repeat(3, minmax(0, 1fr));
  }
}

@media (min-width: 820px) {
  .page-about .about-scope-grid {
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }
}

@media (min-width: 900px) {
  .page-about .about-hero-grid {
    grid-template-columns: minmax(0, 7fr) minmax(0, 4fr);
    align-items: start;
  }
  .page-about .about-split {
    grid-template-columns: minmax(0, 7fr) minmax(0, 4fr);
    align-items: start;
  }
  .page-about .about-batch-grid {
    grid-template-columns: minmax(0, 7fr) minmax(0, 4fr);
    align-items: start;
  }
  .page-about .about-team-grid {
    grid-template-columns: minmax(0, 4fr) minmax(0, 7fr);
    align-items: start;
  }
  .page-about .about-tl-item {
    padding-bottom: clamp(30px, 4vw, 42px);
  }
}

@media (min-width: 860px) {
  .page-about .about-steps {
    grid-template-columns: repeat(3, minmax(0, 1fr));
  }
  .page-about .about-step:nth-child(2) {
    transform: translateY(14px);
  }
  .page-about .about-step:nth-child(2):hover {
    transform: translateY(12px);
  }
  .page-about .about-step:nth-child(3) {
    transform: translateY(28px);
  }
  .page-about .about-step:nth-child(3):hover {
    transform: translateY(26px);
  }
  .page-about .about-step {
    margin-bottom: 28px;
  }
}

@media (min-width: 1000px) {
  .page-about .about-layer:nth-child(2) {
    margin-left: 32px;
  }
  .page-about .about-layer:nth-child(3) {
    margin-left: 64px;
  }
}

@media (max-width: 520px) {
  .page-about .about-hero::after {
    display: none;
  }
  .page-about .about-title {
    font-size: 30px;
  }
  .page-about .about-rule {
    flex-direction: column;
    gap: 8px;
  }
  .page-about .about-rule-num {
    padding-top: 0;
  }
  .page-about .about-layer {
    flex-direction: column;
  }
  .page-about .about-layer:not(:last-child)::after {
    left: 24px;
  }
}

@media (prefers-reduced-motion: reduce) {
  .page-about .about-layer,
  .page-about .about-step,
  .page-about .about-flow-step {
    transition: none;
  }
  .page-about .about-layer:hover,
  .page-about .about-step:hover,
  .page-about .about-flow-step:hover {
    transform: none;
  }
}
<<<END>>>