.page-about {
  --ab-idx: 172px;
  --ab-gap: 40px;
  --ab-paper-hi: #FBF7EC;
  --ab-paper-soft: #3D453E;
  background: var(--ink);
  color: var(--paper);
  font-family: var(--ff-body);
  box-sizing: border-box;
}

.page-about *,
.page-about *::before,
.page-about *::after {
  box-sizing: inherit;
}

.page-about [id] {
  scroll-margin-top: 78px;
}

/* ---------- 首屏 ---------- */
.page-about .ab-hero {
  display: grid;
  gap: 26px;
  padding-top: 26px;
  padding-bottom: 44px;
  border-bottom: 1px solid var(--line);
}

.page-about .ab-hero__main {
  min-width: 0;
}

.page-about .ab-hero h1 {
  font-family: var(--ff-head);
  font-weight: 800;
  font-size: clamp(29px, 7vw, 50px);
  line-height: 1.1;
  letter-spacing: -0.02em;
  margin: 18px 0 16px;
  color: var(--paper);
}

.page-about .ab-hero__lead {
  font-size: 16px;
  line-height: 1.85;
  color: var(--mist);
  max-width: 46ch;
  margin: 0;
}

.page-about .ab-facts {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 18px 14px;
  border: 1px solid var(--line);
  border-top: 3px solid var(--lime);
  background: var(--panel);
  padding: 18px 16px 20px;
  box-shadow: var(--shadow);
}

.page-about .ab-facts__num {
  display: block;
  font-family: var(--ff-num);
  font-size: 32px;
  font-weight: 700;
  line-height: 1;
  color: var(--amber);
  font-variant-numeric: tabular-nums;
}

.page-about .ab-facts__label {
  display: block;
  margin-top: 7px;
  font-size: 12px;
  line-height: 1.55;
  letter-spacing: 0.04em;
  color: var(--mist);
}

@media (min-width: 860px) {
  .page-about .ab-hero {
    grid-template-columns: minmax(0, 1.35fr) minmax(280px, 0.65fr);
    gap: 44px;
    align-items: end;
    padding-top: 40px;
    padding-bottom: 58px;
  }
}

/* ---------- 索引 + 长卷 ---------- */
.page-about .ab-layout {
  display: grid;
  grid-template-columns: 1fr;
  padding-top: 6px;
}

.page-about .ab-index {
  padding: 16px 0 6px;
}

.page-about .ab-index__list {
  list-style: none;
  margin: 0;
  padding: 0;
  display: grid;
  gap: 2px;
}

.page-about .ab-index__link {
  display: flex;
  align-items: baseline;
  gap: 10px;
  min-height: 44px;
  padding: 11px 10px 11px 12px;
  border-left: 2px solid var(--line);
  color: var(--mist);
  text-decoration: none;
  font-size: 13px;
  letter-spacing: 0.02em;
  transition: color var(--dur), border-color var(--dur), background-color var(--dur);
}

.page-about .ab-index__link:hover {
  color: var(--paper);
  border-left-color: var(--stand);
  background: var(--panel);
}

.page-about .ab-index__link:focus-visible {
  outline: 2px solid var(--lime);
  outline-offset: 2px;
  color: var(--paper);
}

.page-about .ab-index__link[aria-current="true"] {
  color: var(--lime);
  border-left-color: var(--lime);
  background: var(--panel);
}

.page-about .ab-index__num {
  font-family: var(--ff-num);
  font-size: 14px;
  color: var(--amber);
  font-variant-numeric: tabular-nums;
}

@media (min-width: 960px) {
  .page-about .ab-layout {
    grid-template-columns: var(--ab-idx) minmax(0, 1fr);
    column-gap: var(--ab-gap);
  }

  .page-about .ab-index {
    position: sticky;
    top: 76px;
    align-self: start;
    padding-top: 34px;
  }
}

/* ---------- 章节 ---------- */
.page-about .ab-ch {
  padding: 32px 0 46px;
}

.page-about .ab-ch--narrow {
  max-width: 800px;
}

.page-about .ab-ch__num {
  display: block;
  font-family: var(--ff-num);
  font-size: 60px;
  font-weight: 700;
  line-height: 0.82;
  color: var(--amber);
  opacity: 0.35;
  font-variant-numeric: tabular-nums;
  margin-bottom: 6px;
}

.page-about .ab-ch h2 {
  font-family: var(--ff-head);
  font-size: clamp(22px, 3.4vw, 30px);
  font-weight: 800;
  line-height: 1.22;
  letter-spacing: -0.02em;
  color: var(--paper);
  margin: 0 0 16px;
}

.page-about .ab-ch h3 {
  font-family: var(--ff-head);
  font-size: 16px;
  font-weight: 800;
  line-height: 1.4;
  margin: 0 0 6px;
  color: var(--paper);
}

.page-about .ab-ch p {
  font-size: 16px;
  line-height: 1.85;
  color: var(--mist);
  margin: 0 0 1.05em;
  max-width: 62ch;
}

@media (min-width: 860px) {
  .page-about .ab-ch__num {
    font-size: 76px;
  }

  .page-about .ab-ch {
    padding: 40px 0 54px;
  }
}

.page-about .ab-split {
  display: grid;
  gap: 24px;
}

.page-about .ab-split__text {
  min-width: 0;
}

@media (min-width: 820px) {
  .page-about .ab-split {
    grid-template-columns: minmax(0, 1.1fr) minmax(0, 0.9fr);
    gap: 34px;
    align-items: start;
  }
}

.page-about .ab-fig {
  margin: 0;
}

.page-about .ab-fig img {
  display: block;
  width: 100%;
  max-width: 100%;
  height: auto;
  object-fit: cover;
  border: 1px solid var(--line);
  background: var(--panel);
  filter: saturate(0.92) contrast(1.04);
}

.page-about .ab-fig--tilt img {
  clip-path: polygon(0 26px, 100% 0, 100% 100%, 0 100%);
}

.page-about .ab-fig figcaption {
  margin-top: 10px;
  font-size: 12px;
  line-height: 1.6;
  letter-spacing: 0.05em;
  color: var(--mist);
}

.page-about .ab-quote {
  margin: 22px 0 0;
  padding: 16px 18px;
  border-left: 3px solid var(--lime);
  background: var(--panel);
  font-family: var(--ff-serif);
  font-size: 17px;
  line-height: 1.8;
  color: var(--paper);
  max-width: 42ch;
}

.page-about .ab-slice {
  height: 6px;
  margin: 0 0 34px;
  background: linear-gradient(90deg, var(--stand) 0%, var(--stand-deep) 55%, var(--line) 100%);
  transform: skewY(-2.2deg);
  transform-origin: left center;
}

/* ---------- 时间轴 ---------- */
.page-about .ab-tl {
  list-style: none;
  margin: 22px 0 0;
  padding: 0;
  position: relative;
}

.page-about .ab-tl::before {
  content: "";
  position: absolute;
  left: 5px;
  top: 14px;
  bottom: 14px;
  width: 1px;
  background: var(--line);
}

.page-about .ab-tl__item {
  position: relative;
  padding: 0 0 16px 30px;
}

.page-about .ab-tl__item::before {
  content: "";
  position: absolute;
  left: 0;
  top: 17px;
  width: 11px;
  height: 11px;
  border-radius: 50%;
  background: var(--ink);
  border: 1.5px solid var(--lime);
}

.page-about .ab-tl__item--now::before {
  background: var(--lime);
}

.page-about .ab-tl__card {
  background: var(--paper);
  color: var(--paperink);
  padding: 14px 16px 16px;
  border-radius: 2px;
  box-shadow: var(--shadow);
}

.page-about .ab-tl__year {
  display: inline-block;
  font-family: var(--ff-num);
  font-size: 13px;
  letter-spacing: 0.1em;
  color: var(--stand);
  margin-bottom: 8px;
  padding-bottom: 3px;
  border-bottom: 1px solid var(--paper-2);
}

.page-about .ab-tl__card h3 {
  color: var(--paperink);
  font-size: 16px;
  margin: 0 0 6px;
}

.page-about .ab-tl__card p {
  color: var(--ab-paper-soft);
  font-size: 14.5px;
  line-height: 1.75;
  margin: 0;
  max-width: none;
}

/* ---------- 团队 ---------- */
.page-about .ab-team {
  display: grid;
  gap: 12px;
  margin: 22px 0 24px;
}

.page-about .ab-team__card {
  border: 1px solid var(--line);
  border-top: 3px solid var(--stand);
  background: var(--panel);
  padding: 16px 15px 18px;
  transition: border-color var(--dur), transform var(--dur);
}

.page-about .ab-team__card:hover {
  border-color: var(--lime);
  transform: translateY(-2px);
}

.page-about .ab-team__name {
  display: block;
  font-family: var(--ff-head);
  font-size: 16px;
  font-weight: 800;
  color: var(--paper);
  margin-bottom: 8px;
}

.page-about .ab-team__card p {
  font-size: 14.5px;
  line-height: 1.75;
  margin: 0;
  color: var(--mist);
  max-width: none;
}

@media (min-width: 780px) {
  .page-about .ab-team {
    grid-template-columns: repeat(3, minmax(0, 1fr));
    gap: 14px;
  }
}

/* ---------- 周节奏 ---------- */
.page-about .ab-rhythm {
  list-style: none;
  margin: 22px 0 0;
  padding: 0;
}

.page-about .ab-rhythm__item {
  display: grid;
  gap: 6px;
  padding: 18px 0;
  border-top: 1px solid var(--line);
}

.page-about .ab-rhythm__item:last-child {
  border-bottom: 1px solid var(--line);
}

.page-about .ab-rhythm__when {
  font-family: var(--ff-num);
  font-size: 19px;
  letter-spacing: 0.04em;
  color: var(--amber);
  font-variant-numeric: tabular-nums;
}

.page-about .ab-rhythm__what h3 {
  margin: 0 0 6px;
}

.page-about .ab-rhythm__what p {
  margin: 0;
  font-size: 15px;
}

.page-about .ab-rhythm__what a {
  color: var(--lime);
  text-decoration: underline;
  text-underline-offset: 3px;
}

@media (min-width: 700px) {
  .page-about .ab-rhythm__item {
    grid-template-columns: 168px minmax(0, 1fr);
    gap: 24px;
    align-items: start;
  }
}

/* ---------- 复核（暖纸面） ---------- */
.page-about .ab-review {
  margin-top: 26px;
  padding: 24px 18px 26px;
  background: var(--paper);
  color: var(--paperink);
  border-radius: 2px;
}

.page-about .ab-review__grid {
  display: grid;
  gap: 22px;
}

.page-about .ab-review p {
  color: var(--paperink);
  font-size: 15px;
  line-height: 1.75;
  margin: 0 0 0.8em;
  max-width: none;
}

.page-about .ab-review h3 {
  color: var(--paperink);
  font-size: 17px;
  margin: 0 0 12px;
}

.page-about .ab-review .ab-fig img {
  border-color: var(--paper-2);
  filter: saturate(0.96);
}

.page-about .ab-flow {
  display: grid;
  gap: 6px;
  margin-bottom: 16px;
}

.page-about .ab-flow__cell {
  display: flex;
  align-items: center;
  justify-content: center;
  min-height: 40px;
  padding: 8px 10px;
  background: var(--paper-2);
  color: var(--paperink);
  font-size: 13px;
  font-weight: 700;
  letter-spacing: 0.02em;
  text-align: center;
  clip-path: polygon(0 0, calc(100% - 12px) 0, 100% 50%, calc(100% - 12px) 100%, 0 100%);
}

@media (min-width: 560px) {
  .page-about .ab-flow {
    grid-template-columns: repeat(4, minmax(0, 1fr));
    gap: 4px;
  }
}

@media (min-width: 880px) {
  .page-about .ab-review {
    padding: 28px 26px 30px;
  }

  .page-about .ab-review__grid {
    grid-template-columns: minmax(0, 0.78fr) minmax(0, 1.22fr);
    gap: 30px;
    align-items: start;
  }
}

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

.page-about .ab-step {
  background: var(--ab-paper-hi);
  border: 1px solid var(--paper-2);
}

.page-about .ab-step > summary {
  display: flex;
  align-items: center;
  gap: 10px;
  min-height: 46px;
  padding: 10px 14px;
  cursor: pointer;
  list-style: none;
  font-family: var(--ff-head);
  font-size: 14.5px;
  font-weight: 800;
  color: var(--paperink);
}

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

.page-about .ab-step > summary::after {
  content: "+";
  margin-left: auto;
  font-family: var(--ff-num);
  font-size: 20px;
  line-height: 1;
  color: var(--stand);
}

.page-about .ab-step[open] > summary::after {
  content: "−";
}

.page-about .ab-step > summary:focus-visible {
  outline: 2px solid var(--stand);
  outline-offset: -2px;
}

.page-about .ab-step p {
  margin: 0;
  padding: 0 14px 14px 46px;
  font-size: 14px;
  line-height: 1.75;
  color: var(--paperink);
  max-width: none;
}

.page-about .ab-step__n {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 22px;
  height: 22px;
  flex: none;
  border-radius: 50%;
  background: var(--stand);
  color: var(--paper);
  font-family: var(--ff-num);
  font-size: 13px;
  line-height: 1;
}

.page-about .ab-review .ab-review__note {
  margin: 20px 0 0;
  padding-top: 14px;
  border-top: 1px solid var(--paper-2);
  font-size: 13.5px;
  line-height: 1.7;
  color: var(--paperink);
}

/* ---------- 接下来 ---------- */
.page-about .ab-next {
  display: grid;
  gap: 12px;
  margin: 22px 0 0;
}

.page-about .ab-next__card {
  position: relative;
  background: var(--panel);
  border: 1px solid var(--line);
  border-radius: 2px;
  padding: 20px 16px 18px;
}

.page-about .ab-next__card::before {
  content: "";
  position: absolute;
  left: 0;
  top: 0;
  width: 34px;
  height: 3px;
  background: var(--stand);
}

.page-about .ab-next__card h3 {
  font-size: 16px;
  margin: 0 0 8px;
}

.page-about .ab-next__card p {
  font-size: 14.5px;
  line-height: 1.75;
  margin: 0;
  max-width: none;
}

@media (min-width: 800px) {
  .page-about .ab-next {
    grid-template-columns: repeat(3, minmax(0, 1fr));
    gap: 14px;
  }
}

.page-about .ab-cta {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 12px;
  margin-top: 30px;
  padding-top: 22px;
  border-top: 1px solid var(--line);
}

.page-about .ab-cta__link {
  font-size: 13.5px;
  color: var(--mist);
  text-decoration: underline;
  text-underline-offset: 4px;
  padding: 8px 0;
}

.page-about .ab-cta__link:hover,
.page-about .ab-cta__link:focus-visible {
  color: var(--lime);
}

@media (prefers-reduced-motion: reduce) {
  .page-about .ab-index__link,
  .page-about .ab-team__card {
    transition: none;
  }
}
<<<END>>>