.page-about {
  --ab-gap: clamp(14px, 2vw, 22px);
  --ab-cut: 26px;
  display: block;
  padding: clamp(20px, 3.5vw, 44px) var(--gutter) clamp(48px, 7vw, 88px);
  color: var(--ink);
  font-family: var(--font-body);
  background:
    radial-gradient(900px 480px at 92% -10%, rgba(47, 243, 214, 0.09), transparent 62%),
    var(--bg);
}

.page-about p {
  margin: 0;
}

.page-about .breadcrumbs {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 8px;
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.08em;
  color: var(--mute);
  margin-bottom: clamp(18px, 3vw, 30px);
}

.page-about .breadcrumbs a {
  color: var(--mute);
  text-decoration: none;
  border-bottom: 1px solid transparent;
  transition: color 160ms var(--ease), border-color 160ms var(--ease);
}

.page-about .breadcrumbs a:hover,
.page-about .breadcrumbs a:focus-visible {
  color: var(--cyan);
  border-bottom-color: var(--cyan);
}

/* 首屏 */
.page-about .ab-hero {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: var(--ab-gap);
  align-items: stretch;
}

.page-about .ab-hero__title {
  margin: 12px 0 0;
  font-family: var(--font-display);
  font-size: clamp(34px, 7.4vw, 82px);
  font-weight: 500;
  line-height: 1.02;
  letter-spacing: -0.01em;
  color: var(--ink);
}

.page-about .ab-lede {
  max-width: 34em;
  margin-top: 18px;
  font-size: 15.5px;
  line-height: 1.85;
  color: var(--ink);
}

.page-about .ab-lede--mute {
  margin-top: 12px;
  font-size: 14.5px;
  color: var(--mute);
}

.page-about .ab-hero__actions {
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
  margin-top: 22px;
}

/* 图片框 */
.page-about .ab-figure {
  margin: 0;
  position: relative;
  overflow: hidden;
  background: var(--panel-2);
  border: 1px solid var(--line);
  clip-path: polygon(0 0, 100% 0, 100% calc(100% - var(--ab-cut)), calc(100% - var(--ab-cut)) 100%, 0 100%);
}

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

.page-about .ab-figure figcaption {
  position: absolute;
  left: 0;
  right: 0;
  bottom: 0;
  padding: 26px 14px 10px;
  font-size: 12px;
  letter-spacing: 0.04em;
  color: var(--sand);
  background: linear-gradient(to top, rgba(6, 18, 15, 0.92), rgba(6, 18, 15, 0));
}

.page-about .ab-figure--hero {
  aspect-ratio: 14 / 9;
}

.page-about .ab-figure--side {
  aspect-ratio: 4 / 3;
}

.page-about .ab-figure--band {
  aspect-ratio: 16 / 6;
  margin-top: clamp(22px, 4vw, 36px);
  --ab-cut: 34px;
}

/* 规模数字 */
.page-about .ab-scale {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: var(--ab-gap);
  margin-top: clamp(22px, 4vw, 34px);
}

.page-about .ab-scale .stat {
  display: flex;
  flex-direction: column;
  gap: 6px;
  padding: 14px 16px 16px;
  background: var(--panel);
  border: 1px solid var(--line);
  border-top: 2px solid var(--cyan-dim);
  clip-path: polygon(0 0, 100% 0, 100% calc(100% - 14px), calc(100% - 14px) 100%, 0 100%);
}

.page-about .ab-scale .stat__value {
  font-family: var(--font-mono);
  font-size: clamp(32px, 6.4vw, 54px);
  line-height: 1;
  color: var(--cyan);
  letter-spacing: -0.02em;
}

.page-about .ab-scale .stat__label {
  font-size: 12.5px;
  line-height: 1.7;
  color: var(--mute);
}

/* 章节头 */
.page-about .ab-sec {
  margin-top: clamp(38px, 6vw, 68px);
}

.page-about .ab-head {
  display: flex;
  align-items: baseline;
  gap: 12px;
  padding-bottom: 10px;
  border-bottom: 1px solid var(--line);
}

.page-about .ab-head__idx {
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.16em;
  color: var(--cyan);
}

.page-about .ab-head__title {
  margin: 0;
  font-family: var(--font-display);
  font-size: clamp(22px, 3.8vw, 40px);
  font-weight: 500;
  line-height: 1.15;
  color: var(--ink);
}

.page-about .ab-copy {
  margin-top: 16px;
  max-width: 34em;
  font-size: 15px;
  line-height: 1.85;
  color: var(--mute);
}

.page-about .ab-copy--intro {
  max-width: 40em;
}

/* 来源与小组 */
.page-about .ab-split {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: var(--ab-gap);
  margin-top: var(--ab-gap);
}

.page-about .ab-crew {
  list-style: none;
  margin: 18px 0 0;
  padding: 0;
  display: grid;
  gap: 10px;
}

.page-about .ab-crew__row {
  display: grid;
  gap: 6px;
  padding: 12px 15px;
  background: var(--panel);
  border: 1px solid var(--line);
  border-left: 2px solid var(--cyan-dim);
}

.page-about .ab-crew__tag {
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.1em;
  color: var(--cyan);
}

.page-about .ab-crew__row p {
  font-size: 14px;
  line-height: 1.8;
  color: var(--mute);
}

/* 层级目录 */
.page-about .ab-tree {
  margin-top: var(--ab-gap);
  padding: clamp(14px, 2.6vw, 26px);
  background: var(--panel);
  border: 1px solid var(--line);
  border-left: 3px solid var(--cyan-dim);
}

.page-about .ab-tree summary {
  list-style: none;
  cursor: pointer;
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 10px;
  padding: 8px 12px;
  background: var(--panel-2);
  border: 1px solid var(--line);
  transition: border-color 160ms var(--ease);
}

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

.page-about .ab-tree summary:hover,
.page-about .ab-tree summary:focus-visible {
  border-color: var(--cyan);
}

.page-about .ab-tree__sum::before {
  content: "+";
  display: inline-block;
  width: 14px;
  font-family: var(--font-mono);
  font-size: 13px;
  color: var(--cyan);
}

.page-about .ab-tree details[open] > .ab-tree__sum::before {
  content: "−";
}

.page-about .ab-tree__lv {
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: 0.1em;
  color: var(--cyan-dim);
}

.page-about .ab-tree__lv--leaf {
  display: inline-block;
  margin: 0 0 8px;
}

.page-about .ab-tree__name {
  font-size: 15px;
  color: var(--ink);
}

.page-about .ab-tree__meta {
  margin-left: auto;
  font-size: 12px;
  color: var(--mute);
}

.page-about .ab-tree__kids {
  margin: 8px 0 0 16px;
  padding-left: 12px;
  border-left: 1px dashed var(--line);
  display: grid;
  gap: 8px;
}

.page-about .ab-tree__leaf-wrap {
  padding: 10px 12px;
  border: 1px solid var(--line);
  background: rgba(18, 48, 42, 0.35);
}

.page-about .ab-tree__leaf {
  list-style: none;
  margin: 0;
  padding: 0;
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
}

.page-about .ab-tree__leaf li {
  padding: 5px 10px;
  font-family: var(--font-mono);
  font-size: 12px;
  color: var(--cyan);
  border: 1px solid var(--cyan-dim);
  clip-path: polygon(0 0, 100% 0, 100% calc(100% - 8px), calc(100% - 8px) 100%, 0 100%);
}

.page-about .ab-tree__note {
  margin-top: 10px;
  font-size: 13px;
  line-height: 1.75;
  color: var(--mute);
}

.page-about .ab-tree__foot {
  margin-top: 16px;
  padding-top: 14px;
  border-top: 1px solid var(--line);
  font-size: 14px;
  line-height: 1.85;
  color: var(--mute);
}

/* 时间轴 */
.page-about .ab-tl {
  list-style: none;
  margin: var(--ab-gap) 0 0;
  padding: 0 0 0 24px;
  position: relative;
  display: grid;
  gap: 12px;
}

.page-about .ab-tl::before {
  content: "";
  position: absolute;
  left: 5px;
  top: 8px;
  bottom: 8px;
  width: 2px;
  background: linear-gradient(var(--cyan), var(--line));
}

.page-about .ab-tl__item {
  position: relative;
}

.page-about .ab-tl__item::before {
  content: "";
  position: absolute;
  left: -24px;
  top: 16px;
  width: 9px;
  height: 9px;
  background: var(--bg);
  border: 2px solid var(--cyan);
  transform: rotate(45deg);
}

.page-about .ab-tl__panel {
  background: var(--panel);
  border: 1px solid var(--line);
  clip-path: polygon(0 0, 100% 0, 100% calc(100% - 12px), calc(100% - 12px) 100%, 0 100%);
}

.page-about .ab-tl__sum {
  list-style: none;
  cursor: pointer;
  display: flex;
  flex-wrap: wrap;
  align-items: baseline;
  gap: 10px;
  padding: 12px 15px;
  transition: background-color 160ms var(--ease);
}

.page-about .ab-tl__sum::-webkit-details-marker {
  display: none;
}

.page-about .ab-tl__sum:hover,
.page-about .ab-tl__sum:focus-visible {
  background: var(--panel-2);
}

.page-about .ab-tl__ver {
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.08em;
  color: var(--orange);
  padding: 2px 8px;
  border: 1px solid rgba(255, 106, 43, 0.45);
}

.page-about .ab-tl__name {
  font-size: 15px;
  font-weight: 600;
  color: var(--ink);
}

.page-about .ab-tl__panel p {
  padding: 0 15px 15px;
  font-size: 14px;
  line-height: 1.85;
  color: var(--mute);
  max-width: 40em;
}

/* 更新节奏 */
.page-about .ab-rhythm {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: var(--ab-gap);
  margin-top: var(--ab-gap);
}

.page-about .ab-rhythm__big {
  padding: clamp(18px, 3vw, 28px);
  background:
    linear-gradient(150deg, rgba(47, 243, 214, 0.14), rgba(47, 243, 214, 0) 58%),
    var(--panel-2);
  border: 1px solid var(--line);
  clip-path: polygon(0 0, 100% 0, 100% calc(100% - 22px), calc(100% - 22px) 100%, 0 100%);
}

.page-about .ab-rhythm__num {
  display: block;
  font-family: var(--font-mono);
  font-size: clamp(44px, 10vw, 78px);
  line-height: 1;
  color: var(--cyan);
  letter-spacing: -0.03em;
}

.page-about .ab-rhythm__unit {
  display: block;
  margin-top: 6px;
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.1em;
  color: var(--sand);
}

.page-about .ab-rhythm__big p {
  margin-top: 14px;
  font-size: 14px;
  line-height: 1.85;
  color: var(--ink);
}

.page-about .ab-rhythm__list {
  list-style: none;
  margin: 0;
  padding: 0;
  display: grid;
  gap: 8px;
}

.page-about .ab-rhythm__list li {
  padding: 11px 14px;
  background: var(--panel);
  border: 1px solid var(--line);
  border-bottom-width: 1px;
  font-size: 14px;
  line-height: 1.8;
  color: var(--mute);
}

.page-about .ab-rhythm__k {
  display: inline-block;
  margin-right: 10px;
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.08em;
  color: var(--cyan);
}

/* 使用场景 */
.page-about .ab-use {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: var(--ab-gap);
  margin-top: var(--ab-gap);
}

.page-about .ab-use__card {
  padding: 18px 18px 20px;
  background: var(--panel);
  border: 1px solid var(--line);
  border-top: 2px solid var(--line);
  clip-path: polygon(0 0, 100% 0, 100% calc(100% - 18px), calc(100% - 18px) 100%, 0 100%);
  transition: border-color 200ms var(--ease), box-shadow 200ms var(--ease);
}

.page-about .ab-use__card:hover,
.page-about .ab-use__card:focus-within {
  border-color: var(--cyan);
  border-top-color: var(--cyan);
  box-shadow: 0 0 0 1px rgba(47, 243, 214, 0.35);
}

.page-about .ab-use__card .tag {
  display: inline-block;
  padding: 3px 9px;
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: 0.1em;
  color: var(--bg);
  background: var(--sand);
}

.page-about .ab-use__card h3 {
  margin: 12px 0 8px;
  font-family: var(--font-display);
  font-size: clamp(20px, 3vw, 26px);
  font-weight: 500;
  line-height: 1.25;
  color: var(--ink);
}

.page-about .ab-use__card p {
  font-size: 14px;
  line-height: 1.85;
  color: var(--mute);
}

.page-about .ab-use__link {
  display: inline-block;
  margin-top: 14px;
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.06em;
  color: var(--cyan);
  text-decoration: none;
  border-bottom: 1px solid var(--cyan-dim);
  padding-bottom: 2px;
}

.page-about .ab-use__link:hover,
.page-about .ab-use__link:focus-visible {
  color: var(--ink);
  border-bottom-color: var(--ink);
}

/* 收尾 */
.page-about .ab-close {
  margin-top: clamp(38px, 6vw, 70px);
  padding: clamp(20px, 3.5vw, 34px);
  display: grid;
  gap: 18px;
  background:
    linear-gradient(115deg, rgba(47, 243, 214, 0.1), rgba(255, 106, 43, 0.08)),
    var(--panel);
  border: 1px solid var(--line);
  clip-path: polygon(0 0, 100% 0, 100% calc(100% - var(--ab-cut)), calc(100% - var(--ab-cut)) 100%, 0 100%);
}

.page-about .ab-close__title {
  margin: 0;
  font-family: var(--font-display);
  font-size: clamp(22px, 4vw, 36px);
  font-weight: 500;
  line-height: 1.2;
  color: var(--ink);
}

.page-about .ab-close__text {
  margin-top: 10px;
  max-width: 38em;
  font-size: 14.5px;
  line-height: 1.85;
  color: var(--mute);
}

.page-about .ab-close__links {
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
}

/* 平板及以上 */
@media (min-width: 640px) {
  .page-about .ab-crew__row {
    grid-template-columns: 132px minmax(0, 1fr);
    align-items: start;
  }

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

@media (min-width: 880px) {
  .page-about .ab-scale {
    grid-template-columns: repeat(4, minmax(0, 1fr));
  }

  .page-about .ab-split {
    grid-template-columns: 5fr 7fr;
    align-items: start;
  }

  .page-about .ab-rhythm {
    grid-template-columns: 4fr 8fr;
    align-items: start;
  }

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

  .page-about .ab-close {
    grid-template-columns: 7fr 5fr;
    align-items: center;
  }

  .page-about .ab-close__links {
    justify-content: flex-end;
  }
}

@media (min-width: 980px) {
  .page-about .ab-hero {
    grid-template-columns: 7fr 5fr;
  }

  .page-about .ab-figure--hero {
    aspect-ratio: auto;
    min-height: 100%;
  }
}

@media (prefers-reduced-motion: reduce) {
  .page-about .ab-figure img,
  .page-about .ab-use__card,
  .page-about .ab-tree summary,
  .page-about .ab-tl__sum,
  .page-about .breadcrumbs a {
    transition: none;
  }
}
<<<END>>>