.page-about {
  --ab-radius: 4px;
  padding: 28px 0 76px;
}

.page-about .ab-shell {
  padding-inline: clamp(16px, 4vw, 40px);
}

/* 面包屑 */
.page-about .ab-crumbs ol {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 8px;
  margin: 0 0 26px;
  padding: 0;
  list-style: none;
  font-family: var(--sf-mono);
  font-size: 11px;
  letter-spacing: .12em;
  text-transform: uppercase;
  color: var(--sf-text-dim);
}
.page-about .ab-crumbs li + li::before {
  content: "/";
  margin-right: 8px;
  color: var(--sf-steel);
}
.page-about .ab-crumbs a {
  color: var(--sf-text-dim);
  text-decoration: none;
  border-bottom: 1px solid transparent;
  transition: color .2s var(--sf-ease), border-color .2s var(--sf-ease);
}
.page-about .ab-crumbs a:hover,
.page-about .ab-crumbs a:focus-visible {
  color: var(--sf-cyan);
  border-bottom-color: var(--sf-cyan);
}
.page-about .ab-crumbs [aria-current="page"] {
  color: var(--sf-cyan);
}

/* 首屏 */
.page-about .ab-hero {
  padding: 4px 0 40px;
  border-bottom: var(--sf-line);
}
.page-about .ab-hero__title {
  margin: 14px 0 18px;
  font-family: var(--sf-sans);
  font-weight: 900;
  font-size: clamp(30px, 6.4vw, 54px);
  line-height: 1.12;
  letter-spacing: -.02em;
  color: var(--sf-text);
}
.page-about .ab-hero__title em {
  font-style: normal;
  display: inline-block;
  color: var(--sf-cyan);
}
.page-about .ab-hero__lede {
  max-width: 64ch;
  margin: 0;
  font-size: 16px;
  line-height: 1.85;
  color: var(--sf-text-dim);
}
.page-about .ab-hero__quote {
  margin: 26px 0 0;
  padding: 6px 0 6px 18px;
  border-left: 2px solid var(--sf-orange);
  font-family: var(--sf-serif);
  font-size: clamp(17px, 2.4vw, 21px);
  line-height: 1.7;
  color: var(--sf-pearl);
}

/* 数据条 */
.page-about .ab-stats {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 1px;
  margin: 30px 0 0;
  padding: 0;
  list-style: none;
  background: var(--sf-steel);
  border: var(--sf-line);
  border-radius: var(--ab-radius);
  overflow: hidden;
}
.page-about .ab-stat {
  background: var(--sf-night);
  padding: 16px 16px 18px;
}
.page-about .ab-stat__num {
  display: block;
  font-family: var(--sf-mono);
  font-size: clamp(22px, 3.4vw, 30px);
  font-weight: 700;
  line-height: 1.1;
  color: var(--sf-cyan);
  letter-spacing: -.02em;
}
.page-about .ab-stat__num--orange {
  color: var(--sf-orange);
}
.page-about .ab-stat__label {
  display: block;
  margin-top: 6px;
  font-size: 12px;
  letter-spacing: .06em;
  color: var(--sf-text-dim);
}

/* 主体两栏 */
.page-about .ab-body {
  display: grid;
  gap: 30px;
  padding-top: 40px;
}
.page-about .ab-index {
  border-top: var(--sf-line-soft);
  padding-top: 14px;
}
.page-about .ab-index__title {
  margin: 0 0 12px;
  font-family: var(--sf-serif);
  font-size: 13px;
  letter-spacing: .2em;
  color: var(--sf-amber);
}
.page-about .ab-index__list {
  display: flex;
  flex-wrap: wrap;
  gap: 8px 16px;
  margin: 0;
  padding: 0;
  list-style: none;
}
.page-about .ab-index__list a {
  display: inline-flex;
  align-items: baseline;
  gap: 7px;
  font-size: 13px;
  color: var(--sf-text-dim);
  text-decoration: none;
  transition: color .2s var(--sf-ease);
}
.page-about .ab-index__num {
  font-family: var(--sf-mono);
  font-size: 10.5px;
  color: var(--sf-cyan);
  letter-spacing: .08em;
}
.page-about .ab-index__list a:hover,
.page-about .ab-index__list a:focus-visible {
  color: var(--sf-text);
}

/* 章节 */
.page-about .ab-chapters {
  display: block;
  min-width: 0;
}
.page-about .ab-chapter {
  position: relative;
  margin: 0 0 24px;
  padding: 28px 20px 32px;
  border: var(--sf-line-soft);
  border-radius: var(--ab-radius);
  box-shadow: var(--sf-shadow);
  scroll-margin-top: 92px;
}
.page-about .ab-chapter--wine {
  background:
    radial-gradient(120% 90% at 100% 0%, rgba(43,13,24,.95), transparent 62%),
    linear-gradient(165deg, #1B0910, var(--sf-night) 72%);
}
.page-about .ab-chapter--teal {
  background:
    radial-gradient(110% 80% at 0% 0%, rgba(10,43,45,.95), transparent 66%),
    linear-gradient(170deg, #071A1B, var(--sf-night) 78%);
}
.page-about .ab-chapter--indigo {
  background:
    radial-gradient(120% 85% at 90% 10%, rgba(24,19,56,.98), transparent 68%),
    linear-gradient(165deg, #0C0A22, var(--sf-night) 80%);
}
.page-about .ab-chapter--night {
  background: linear-gradient(180deg, #08101C, var(--sf-night));
  border-color: rgba(57,244,212,.28);
}
.page-about .ab-chapter--paper {
  background: linear-gradient(180deg, var(--sf-pearl), #EDE5D6);
  border-color: rgba(18,23,34,.16);
  color: var(--sf-ink);
}

.page-about .ab-chapter__head {
  display: flex;
  align-items: baseline;
  gap: 14px;
  margin-bottom: 22px;
  padding-bottom: 14px;
  border-bottom: var(--sf-line-soft);
}
.page-about .ab-chapter--paper .ab-chapter__head {
  border-bottom-color: rgba(18,23,34,.18);
}
.page-about .ab-chapter__num {
  flex: none;
  font-family: var(--sf-serif);
  font-size: clamp(24px, 4vw, 34px);
  line-height: 1;
  color: rgba(57,244,212,.42);
}
.page-about .ab-chapter--paper .ab-chapter__num {
  color: rgba(43,13,24,.35);
}
.page-about .ab-chapter__title {
  margin: 0;
  font-family: var(--sf-sans);
  font-weight: 800;
  font-size: clamp(20px, 3.6vw, 28px);
  line-height: 1.3;
  letter-spacing: -.01em;
  color: var(--sf-text);
}
.page-about .ab-chapter--paper .ab-chapter__title {
  color: var(--sf-ink);
}

/* 正文 */
.page-about .ab-p {
  max-width: 64ch;
  margin: 0 0 16px;
  font-size: 15.5px;
  line-height: 1.85;
  color: var(--sf-text-dim);
}
.page-about .ab-p:last-child {
  margin-bottom: 0;
}
.page-about .ab-p--ink {
  color: #3A4254;
}

/* 图片容器 */
.page-about .ab-media {
  position: relative;
  margin: 22px 0 0;
  border: var(--sf-line);
  border-radius: var(--ab-radius);
  overflow: hidden;
  background: var(--sf-indigo);
}
.page-about .ab-media img {
  display: block;
  width: 100%;
  height: auto;
  max-width: 100%;
  object-fit: cover;
  filter: saturate(.9) contrast(1.05);
}
.page-about .ab-media::after {
  content: "";
  position: absolute;
  inset: 0;
  pointer-events: none;
  background:
    repeating-linear-gradient(0deg, rgba(57,244,212,.09) 0 1px, transparent 1px 34px),
    linear-gradient(180deg, rgba(6,10,19,.05), rgba(6,10,19,.62));
}
.page-about .ab-media__cap {
  position: relative;
  z-index: 1;
  margin: 0;
  padding: 10px 14px;
  font-family: var(--sf-mono);
  font-size: 11px;
  letter-spacing: .05em;
  line-height: 1.6;
  color: var(--sf-text-dim);
  background: rgba(6,10,19,.78);
  border-top: var(--sf-line-soft);
}

/* 01 起点 */
.page-about .ab-origin {
  display: grid;
  gap: 24px;
}
.page-about .ab-rules {
  margin: 22px 0 0;
  padding: 0;
  list-style: none;
  border-top: var(--sf-line-soft);
}
.page-about .ab-rules li {
  display: grid;
  gap: 4px;
  padding: 14px 0;
  border-bottom: var(--sf-line-soft);
}
.page-about .ab-rules__k {
  font-family: var(--sf-mono);
  font-size: 12px;
  letter-spacing: .14em;
  color: var(--sf-cyan);
}
.page-about .ab-rules__v {
  font-size: 14.5px;
  line-height: 1.75;
  color: var(--sf-text-dim);
}

/* 02 时间线 */
.page-about .ab-timeline__bg {
  position: relative;
  margin: 24px 0 20px;
  border: var(--sf-line-soft);
  border-radius: var(--ab-radius);
  overflow: hidden;
  height: 132px;
}
.page-about .ab-timeline__bg img {
  width: 100%;
  height: 100%;
  max-width: 100%;
  object-fit: cover;
  display: block;
  opacity: .5;
  filter: grayscale(.2) contrast(1.15);
}
.page-about .ab-timeline__bg::after {
  content: "";
  position: absolute;
  inset: 0;
  background: linear-gradient(90deg, rgba(6,10,19,.15), rgba(6,10,19,.9));
  pointer-events: none;
}
.page-about .ab-timeline {
  position: relative;
  margin: 0;
  padding: 4px 0 4px 26px;
  list-style: none;
}
.page-about .ab-timeline::before {
  content: "";
  position: absolute;
  left: 5px;
  top: 8px;
  bottom: 14px;
  width: 1px;
  background: linear-gradient(180deg, var(--sf-cyan), rgba(57,244,212,.28) 55%, rgba(38,48,67,0));
}
.page-about .ab-node {
  position: relative;
  padding: 0 0 26px;
  scroll-margin-top: 96px;
}
.page-about .ab-node:last-child {
  padding-bottom: 0;
}
.page-about .ab-node::before {
  content: "";
  position: absolute;
  left: -25px;
  top: 6px;
  width: 9px;
  height: 9px;
  border-radius: 50%;
  background: var(--sf-night);
  border: 1px solid var(--sf-cyan);
  box-shadow: 0 0 0 4px rgba(57,244,212,.08);
}
.page-about .ab-node--now::before {
  background: var(--sf-cyan);
  box-shadow: 0 0 0 5px rgba(57,244,212,.16);
}
.page-about .ab-node__ver {
  margin: 0 0 6px;
  font-family: var(--sf-mono);
  font-size: 11.5px;
  letter-spacing: .14em;
  color: var(--sf-amber);
}
.page-about .ab-node--now .ab-node__ver {
  color: var(--sf-cyan);
}
.page-about .ab-node__title {
  margin: 0 0 8px;
  font-family: var(--sf-sans);
  font-size: 17px;
  font-weight: 700;
  line-height: 1.5;
  color: var(--sf-text);
}
.page-about .ab-node .ab-p {
  margin: 0;
  font-size: 14.5px;
}

/* 03 三条内容线 */
.page-about .ab-lines {
  margin: 24px 0 0;
  padding: 0;
  list-style: none;
}
.page-about .ab-line {
  position: relative;
  padding: 18px 0 18px 18px;
  border-left: 2px solid var(--sf-steel);
}
.page-about .ab-line + .ab-line {
  margin-top: 6px;
}
.page-about .ab-line--cyan {
  border-left-color: var(--sf-cyan);
}
.page-about .ab-line--orange {
  border-left-color: var(--sf-orange);
}
.page-about .ab-line--amber {
  border-left-color: var(--sf-amber);
}
.page-about .ab-line__idx {
  margin: 0 0 8px;
  font-family: var(--sf-mono);
  font-size: 11px;
  letter-spacing: .18em;
  color: var(--sf-text-dim);
}
.page-about .ab-line__title {
  margin: 0 0 10px;
  font-family: var(--sf-sans);
  font-size: 18px;
  font-weight: 800;
  line-height: 1.4;
  color: var(--sf-text);
}
.page-about .ab-line .ab-p {
  margin: 0;
  font-size: 14.5px;
}
.page-about .ab-lines__media {
  margin-top: 26px;
}

/* 04 团队 */
.page-about .ab-team {
  display: grid;
  gap: 0;
  margin: 22px 0 0;
  padding: 0;
  list-style: none;
  border-top: 1px solid rgba(18,23,34,.16);
}
.page-about .ab-team__item {
  padding: 20px 0;
  border-bottom: 1px solid rgba(18,23,34,.16);
}
.page-about .ab-team__mark {
  margin: 0 0 8px;
  font-family: var(--sf-serif);
  font-size: 26px;
  line-height: 1;
  color: rgba(43,13,24,.42);
}
.page-about .ab-team__title {
  margin: 0 0 8px;
  font-family: var(--sf-sans);
  font-size: 17px;
  font-weight: 800;
  color: var(--sf-ink);
}
.page-about .ab-team__desc {
  margin: 0;
  font-size: 14.5px;
  line-height: 1.78;
  color: #4A5163;
}
.page-about .ab-team__note {
  margin-top: 20px;
  padding: 16px 18px;
  border-left: 2px solid var(--sf-wine);
  background: rgba(18,23,34,.05);
}

/* 05 合作 */
.page-about .ab-plays {
  display: grid;
  gap: 1px;
  margin: 24px 0 30px;
  padding: 0;
  list-style: none;
  background: var(--sf-steel);
  border: var(--sf-line-soft);
  border-radius: var(--ab-radius);
  overflow: hidden;
}
.page-about .ab-play {
  padding: 18px 16px;
  background: rgba(6,10,19,.72);
}
.page-about .ab-play__title {
  margin: 0 0 8px;
  font-family: var(--sf-sans);
  font-size: 16px;
  font-weight: 800;
  color: var(--sf-cyan);
}
.page-about .ab-play__desc {
  margin: 0;
  font-size: 14px;
  line-height: 1.78;
  color: var(--sf-text-dim);
}
.page-about .ab-flow__title {
  margin: 0 0 6px;
  font-family: var(--sf-serif);
  font-size: 18px;
  font-weight: 400;
  letter-spacing: .04em;
  color: var(--sf-pearl);
}
.page-about .ab-flow {
  border-top: var(--sf-line-soft);
}
.page-about .ab-step {
  border-bottom: var(--sf-line-soft);
}
.page-about .ab-step summary {
  display: flex;
  align-items: center;
  gap: 12px;
  padding: 15px 0;
  cursor: pointer;
  list-style: none;
  font-family: var(--sf-sans);
  font-size: 15px;
  font-weight: 700;
  color: var(--sf-text);
  transition: color .2s var(--sf-ease);
}
.page-about .ab-step summary::-webkit-details-marker {
  display: none;
}
.page-about .ab-step summary::after {
  content: "+";
  margin-left: auto;
  font-family: var(--sf-mono);
  font-size: 16px;
  color: var(--sf-cyan);
}
.page-about .ab-step[open] summary::after {
  content: "−";
}
.page-about .ab-step summary:hover,
.page-about .ab-step summary:focus-visible {
  color: var(--sf-cyan);
}
.page-about .ab-step__num {
  font-family: var(--sf-mono);
  font-size: 11px;
  letter-spacing: .12em;
  color: var(--sf-orange);
}
.page-about .ab-step__body {
  margin: 0 0 16px;
  padding-left: 12px;
  border-left: 1px solid rgba(57,244,212,.3);
  font-size: 14px;
  line-height: 1.8;
  color: var(--sf-text-dim);
}

/* 06 承诺与联系 */
.page-about .ab-promise {
  margin: 22px 0 0;
  padding: 0;
  list-style: none;
}
.page-about .ab-promise li {
  display: grid;
  gap: 5px;
  padding: 15px 0;
  border-top: var(--sf-line-soft);
}
.page-about .ab-promise li:last-child {
  border-bottom: var(--sf-line-soft);
}
.page-about .ab-promise__k {
  font-family: var(--sf-mono);
  font-size: 11.5px;
  letter-spacing: .16em;
  color: var(--sf-orange);
}
.page-about .ab-promise__v {
  font-size: 14.5px;
  line-height: 1.78;
  color: var(--sf-text-dim);
}
.page-about .ab-actions {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
  margin-top: 26px;
}
.page-about .ab-actions .sf-btn {
  flex: 1 1 auto;
  text-align: center;
  justify-content: center;
}
.page-about .ab-contact {
  margin-top: 28px;
  padding-top: 18px;
  border-top: var(--sf-line-soft);
}
.page-about .ab-contact__row {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 8px 14px;
  padding: 10px 0;
}
.page-about .ab-contact__label {
  flex: none;
  min-width: 72px;
  font-family: var(--sf-mono);
  font-size: 11px;
  letter-spacing: .14em;
  color: var(--sf-text-dim);
}
.page-about .ab-contact__value {
  font-family: var(--sf-mono);
  font-size: 14px;
  letter-spacing: .01em;
  color: var(--sf-text);
  word-break: break-all;
}
.page-about .ab-copy {
  font-family: var(--sf-mono);
  font-size: 11px;
  letter-spacing: .1em;
}

/* 显现动效 */
.page-about .sf-reveal {
  opacity: 0;
  transform: translateY(14px);
  transition: opacity .55s var(--sf-ease), transform .55s var(--sf-ease);
}
.page-about .sf-reveal.is-in {
  opacity: 1;
  transform: none;
}

/* 平板以上 */
@media (min-width: 700px) {
  .page-about .ab-stats {
    grid-template-columns: repeat(4, minmax(0, 1fr));
  }
  .page-about .ab-chapter {
    padding: 34px 30px 40px;
  }
  .page-about .ab-origin {
    grid-template-columns: minmax(0, 1.05fr) minmax(0, .95fr);
    gap: 30px;
    align-items: start;
  }
  .page-about .ab-origin__media {
    margin-top: 4px;
  }
  .page-about .ab-timeline__bg {
    height: 180px;
  }
  .page-about .ab-plays {
    grid-template-columns: repeat(3, minmax(0, 1fr));
  }
  .page-about .ab-team {
    grid-template-columns: repeat(3, minmax(0, 1fr));
    gap: 0 28px;
    border-bottom: 1px solid rgba(18,23,34,.16);
  }
  .page-about .ab-team__item {
    border-bottom: 0;
    padding: 22px 0 6px;
  }
  .page-about .ab-team__item:nth-child(2) {
    margin-top: 26px;
  }
  .page-about .ab-contact__row {
    flex-wrap: nowrap;
  }
}

/* 桌面：左侧章节索引跟随 */
@media (min-width: 1024px) {
  .page-about .ab-body {
    grid-template-columns: 168px minmax(0, 1fr);
    gap: 46px;
    padding-top: 48px;
  }
  .page-about .ab-index {
    position: sticky;
    top: 26px;
    align-self: start;
    border-top: 0;
    padding-top: 0;
  }
  .page-about .ab-index__list {
    display: block;
    border-left: var(--sf-line-soft);
  }
  .page-about .ab-index__list li {
    margin-bottom: 16px;
  }
  .page-about .ab-index__list a {
    padding-left: 12px;
    margin-left: -1px;
    border-left: 1px solid transparent;
    transition: color .2s var(--sf-ease), border-color .2s var(--sf-ease);
  }
  .page-about .ab-index__list a:hover,
  .page-about .ab-index__list a:focus-visible {
    color: var(--sf-cyan);
    border-left-color: var(--sf-cyan);
  }
  .page-about .ab-line {
    padding-left: 22px;
  }
  .page-about .ab-lines {
    display: grid;
    gap: 8px;
  }
  .page-about .ab-line:nth-child(2) {
    margin-left: 22px;
  }
  .page-about .ab-line:nth-child(3) {
    margin-left: 44px;
  }
  .page-about .ab-actions .sf-btn {
    flex: 0 0 auto;
    min-width: 160px;
  }
}

@media (prefers-reduced-motion: reduce) {
  .page-about .sf-reveal {
    opacity: 1;
    transform: none;
    transition: none;
  }
}
<<<END>>>