.page-about {
  --ab-rule: var(--rule-600);
  --ab-emphasis: var(--ember-500);
  --ab-signal: var(--aqua-400);
  --ab-panel: rgba(16, 38, 31, .62);
  background: var(--ink-900);
  color: var(--text-100);
  font-family: var(--font-sans);
  font-size: 16px;
  line-height: 1.8;
}

.page-about a {
  color: var(--ab-signal);
  text-decoration: none;
}

.page-about a:hover,
.page-about a:focus-visible {
  text-decoration: underline;
  text-underline-offset: 3px;
}

.page-about .mk-btn--ember {
  color: var(--ink-900);
}

.page-about .mk-btn--ghost {
  color: var(--ab-signal);
}

.page-about .mk-mono {
  font-family: var(--font-mono);
}

/* ---------- 首屏框景 ---------- */
.ab-hero {
  position: relative;
  padding: clamp(20px, 5vw, 34px) 0 clamp(34px, 7vw, 76px);
  border-bottom: 1px solid var(--ab-rule);
  background:
    radial-gradient(120% 96% at 86% 0%, rgba(53, 224, 196, .10), transparent 58%),
    linear-gradient(180deg, rgba(255, 122, 58, .06), transparent 44%),
    var(--ink-900);
}

.ab-crumb {
  font-size: 13px;
  letter-spacing: .06em;
}

.ab-frame {
  position: relative;
  margin-top: clamp(16px, 4vw, 30px);
  padding: clamp(20px, 5vw, 54px);
  border: 1px solid var(--ab-rule);
  background: linear-gradient(180deg, rgba(16, 38, 31, .88), rgba(10, 27, 23, .55));
}

.ab-frame::before,
.ab-frame::after {
  content: "";
  position: absolute;
  width: 46px;
  height: 3px;
  background: var(--ab-emphasis);
}

.ab-frame::before {
  top: -2px;
  left: clamp(20px, 5vw, 54px);
}

.ab-frame::after {
  bottom: -2px;
  right: clamp(20px, 5vw, 54px);
  background: var(--ab-signal);
}

.ab-frame__tag {
  margin: 0;
  font-size: 12px;
  letter-spacing: .2em;
  color: var(--amber-300);
}

.ab-frame__title {
  margin: 14px 0 18px;
  max-width: 22ch;
  font-size: clamp(27px, 6vw, 58px);
  font-weight: 900;
  line-height: 1.2;
  letter-spacing: -.01em;
  color: var(--text-100);
}

.ab-frame__lead {
  margin: 0;
  max-width: 62ch;
  font-size: clamp(15px, 2.4vw, 17px);
  line-height: 1.85;
  color: var(--cream-300);
}

.ab-frame__acts {
  display: flex;
  flex-wrap: wrap;
  gap: 12px 16px;
  margin-top: 26px;
}

.ab-frame__acts--end {
  margin-top: 30px;
}

/* ---------- 首屏数据带 ---------- */
.ab-stats {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 1px;
  margin: clamp(22px, 5vw, 38px) 0 0;
  border: 1px solid var(--ab-rule);
  background: var(--ab-rule);
}

.ab-stats__cell {
  padding: 15px 14px;
  background: var(--ink-900);
}

.ab-stats__cell dt {
  font-size: 13px;
  font-weight: 600;
  letter-spacing: .06em;
  color: var(--text-400);
}

.ab-stats__cell dd {
  margin: 6px 0 0;
  font-size: 14px;
  color: var(--cream-300);
}

.ab-stats__num {
  display: inline-block;
  margin-right: 4px;
  font-size: clamp(22px, 4vw, 30px);
  font-weight: 700;
  line-height: 1.1;
  color: var(--ab-signal);
}

/* ---------- 章节索引条 ---------- */
.ab-index {
  position: sticky;
  top: var(--header-h);
  z-index: 5;
  border-bottom: 1px solid var(--ab-rule);
  background: var(--glass-700);
  backdrop-filter: blur(10px);
  -webkit-backdrop-filter: blur(10px);
}

.ab-index__list {
  display: flex;
  gap: 20px;
  margin: 0;
  padding: 12px 0;
  list-style: none;
  overflow-x: auto;
  scrollbar-width: none;
}

.ab-index__list::-webkit-scrollbar {
  display: none;
}

.ab-index__list li {
  flex: 0 0 auto;
}

.ab-index__list a {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  font-size: 14px;
  font-weight: 600;
  color: var(--text-400);
  white-space: nowrap;
}

.ab-index__list a span {
  font-size: 12px;
  letter-spacing: .1em;
  color: var(--ab-emphasis);
}

.ab-index__list a[aria-current] {
  color: var(--ab-signal);
}

/* ---------- 章节骨架 ---------- */
.ab-sheet {
  background: var(--ink-900);
}

.ab-chapter {
  padding: clamp(36px, 7vw, 84px) 0;
  border-top: 1px solid var(--ab-rule);
}

.ab-chapter__grid {
  display: grid;
  gap: clamp(16px, 4vw, 44px);
}

.ab-chapter__num {
  display: block;
  font-size: 12px;
  font-weight: 700;
  letter-spacing: .22em;
  color: var(--ab-emphasis);
}

.ab-chapter__title {
  margin: 10px 0 0;
  font-size: clamp(23px, 4.6vw, 38px);
  font-weight: 800;
  line-height: 1.25;
  color: var(--text-100);
}

.ab-chapter__kicker {
  margin: 10px 0 0;
  font-size: 13px;
  font-weight: 600;
  letter-spacing: .12em;
  color: var(--text-400);
}

.ab-chapter__body > p {
  margin: 0 0 1.5em;
  max-width: 64ch;
  color: var(--text-100);
}

.ab-chapter__body > p:last-child {
  margin-bottom: 0;
}

.ab-chapter__tail {
  padding-left: 16px;
  border-left: 2px solid var(--ab-emphasis);
  color: var(--cream-300);
  font-size: 15px;
}

.ab-chapter__note {
  margin-top: 22px;
  padding: 14px 16px;
  border: 1px dashed var(--ab-rule);
  border-radius: 2px;
  font-size: 14px;
  line-height: 1.75;
  color: var(--cream-300);
}

/* ---------- 功能清单 ---------- */
.ab-feature {
  display: grid;
  gap: 1px;
  margin: 8px 0 0;
  padding: 0;
  list-style: none;
  border-top: 1px solid var(--ab-rule);
  border-bottom: 1px solid var(--ab-rule);
  background: var(--ab-rule);
}

.ab-feature li {
  padding: 18px 16px;
  background: var(--ink-900);
}

.ab-feature h3 {
  margin: 0 0 6px;
  font-size: 18px;
  font-weight: 700;
  color: var(--text-100);
}

.ab-feature h3::before {
  content: "— ";
  color: var(--ab-emphasis);
}

.ab-feature p {
  margin: 0;
  font-size: 14px;
  line-height: 1.75;
  color: var(--cream-300);
}

.ab-inline {
  margin-top: 24px;
  padding-left: 16px;
  border-left: 2px solid var(--ab-signal);
}

.ab-inline p {
  margin: 0;
  font-size: 15px;
  color: var(--cream-300);
}

.ab-inline__links {
  display: flex;
  flex-wrap: wrap;
  gap: 8px 22px;
  margin-top: 12px !important;
  font-size: 14px;
}

/* ---------- 图与图例 ---------- */
.ab-figure {
  margin: 26px 0 0;
}

.ab-figure--last {
  margin-top: 30px;
}

.ab-figure img {
  display: block;
  width: 100%;
  height: auto;
  object-fit: cover;
  border: 1px solid var(--ab-rule);
  background: var(--ink-800);
}

.ab-figure figcaption {
  margin-top: 10px;
  max-width: 60ch;
  font-size: 13px;
  font-weight: 600;
  line-height: 1.7;
  color: var(--text-400);
}

.ab-legend {
  display: grid;
  gap: 14px;
  margin: 24px 0 0;
  padding: 0;
  list-style: none;
}

.ab-legend li {
  display: grid;
  grid-template-columns: auto minmax(0, 1fr);
  gap: 14px;
  padding-bottom: 14px;
  border-bottom: 1px dashed var(--ab-rule);
}

.ab-legend__num {
  font-size: 22px;
  font-weight: 700;
  line-height: 1.2;
  color: var(--amber-300);
}

.ab-legend h3 {
  margin: 0 0 4px;
  font-size: 16px;
  font-weight: 700;
}

.ab-legend p {
  margin: 0;
  font-size: 14px;
  line-height: 1.75;
  color: var(--cream-300);
}

/* ---------- 五环节流程 ---------- */
.ab-flow {
  display: flex;
  gap: 14px;
  margin: 26px 0 0;
  padding: 0 0 8px;
  list-style: none;
  overflow-x: auto;
  scroll-snap-type: x mandatory;
  scrollbar-width: thin;
}

.ab-flow li {
  flex: 0 0 78%;
  scroll-snap-align: start;
  padding: 16px;
  border: 1px solid var(--ab-rule);
  background: var(--ab-panel);
}

.ab-flow__num {
  display: block;
  font-size: 12px;
  font-weight: 700;
  letter-spacing: .18em;
  color: var(--ab-emphasis);
}

.ab-flow h3 {
  margin: 10px 0 4px;
  font-size: 16px;
  font-weight: 700;
}

.ab-flow p {
  margin: 0;
  font-size: 14px;
  line-height: 1.7;
  color: var(--cream-300);
}

/* ---------- 覆盖宽幅章节 ---------- */
.ab-chapter__head {
  max-width: 62ch;
  margin-bottom: clamp(20px, 4vw, 34px);
}

.ab-chapter__headlead {
  margin: 14px 0 0;
  font-size: 15px;
  color: var(--cream-300);
}

.ab-cover {
  margin: 0 0 clamp(20px, 4vw, 32px);
}

.ab-cover img {
  display: block;
  width: 100%;
  height: auto;
  object-fit: cover;
  border: 1px solid var(--ab-rule);
  background: var(--ink-800);
}

.ab-cover figcaption {
  margin-top: 10px;
  font-size: 13px;
  font-weight: 600;
  color: var(--text-400);
}

.ab-metrics {
  display: grid;
  gap: 1px;
  border: 1px solid var(--ab-rule);
  background: var(--ab-rule);
}

.ab-metric {
  padding: 20px 18px;
  background: var(--ink-800);
}

.ab-metric__num {
  display: block;
  font-size: clamp(21px, 4.2vw, 28px);
  font-weight: 700;
  line-height: 1.2;
  color: var(--ab-signal);
}

.ab-metric p {
  margin: 10px 0 0;
  font-size: 14px;
  line-height: 1.75;
  color: var(--cream-300);
}

/* ---------- 合作方向 ---------- */
.ab-coop {
  display: grid;
  gap: 14px;
  margin: 24px 0;
  padding: 0;
  list-style: none;
}

.ab-coop li {
  position: relative;
  padding: 18px 18px 18px 54px;
  border: 1px solid var(--ab-rule);
  background: var(--ab-panel);
}

.ab-coop li > span {
  position: absolute;
  top: 18px;
  left: 18px;
  font-size: 14px;
  font-weight: 700;
  color: var(--ab-emphasis);
}

.ab-coop h3 {
  margin: 0 0 6px;
  font-size: 17px;
  font-weight: 700;
}

.ab-coop p {
  margin: 0;
  font-size: 14px;
  line-height: 1.75;
  color: var(--cream-300);
}

/* ---------- 联络 ---------- */
.ab-contact {
  display: grid;
  gap: 1px;
  margin: 22px 0 0;
  padding: 0;
  list-style: none;
  border: 1px solid var(--ab-rule);
  background: var(--ab-rule);
}

.ab-contact li {
  display: grid;
  gap: 6px;
  padding: 14px 16px;
  background: var(--ink-900);
}

.ab-contact li > span:first-child {
  font-size: 13px;
  font-weight: 600;
  letter-spacing: .08em;
  color: var(--text-400);
}

.ab-copy {
  padding: 0;
  border: none;
  background: none;
  font-family: var(--font-mono);
  font-size: 15px;
  text-align: left;
  color: var(--ab-signal);
  cursor: pointer;
  word-break: break-all;
}

.ab-copy:hover,
.ab-copy:focus-visible {
  text-decoration: underline;
  text-underline-offset: 3px;
}

.ab-copy[data-copied]::after {
  content: " 已复制";
  font-size: 12px;
  color: var(--amber-300);
}

.ab-contact__plain {
  font-family: var(--font-mono);
  font-size: 15px;
  color: var(--text-100);
}

.ab-legal {
  margin: 26px 0 0;
  font-size: 12px;
  letter-spacing: .1em;
  color: var(--text-400);
  font-weight: 600;
}

/* ---------- 响应式 ---------- */
@media (min-width: 620px) {
  .ab-stats {
    grid-template-columns: repeat(4, minmax(0, 1fr));
  }

  .ab-feature {
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }

  .ab-coop {
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }

  .ab-contact {
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }

  .ab-metrics {
    grid-template-columns: repeat(3, minmax(0, 1fr));
  }
}

@media (min-width: 900px) {
  .ab-chapter__grid {
    grid-template-columns: minmax(0, 3.2fr) minmax(0, 8.8fr);
    align-items: start;
  }

  .ab-chapter__rail {
    position: sticky;
    top: calc(var(--header-h) + 72px);
  }

  .ab-chapter__title {
    max-width: 14ch;
  }

  .ab-flow {
    display: grid;
    grid-template-columns: repeat(5, minmax(0, 1fr));
    gap: 1px;
    overflow: visible;
    padding-bottom: 0;
    border: 1px solid var(--ab-rule);
    background: var(--ab-rule);
  }

  .ab-flow li {
    flex: none;
    border: none;
    background: var(--ink-900);
  }

  .ab-chapter__head {
    display: grid;
    grid-template-columns: minmax(0, 3.2fr) minmax(0, 8.8fr);
    max-width: none;
    align-items: end;
    gap: 4px 44px;
  }

  .ab-chapter__head .ab-chapter__num {
    grid-column: 1;
  }

  .ab-chapter__head .ab-chapter__title {
    grid-column: 1;
    max-width: 16ch;
  }

  .ab-chapter__headlead {
    grid-column: 2;
    grid-row: 1 / span 2;
    margin: 0;
    align-self: end;
  }
}

@media (min-width: 1100px) {
  .ab-frame__title {
    max-width: 24ch;
  }
}
<<<END>>>