.page-about {
  --ab-gap: clamp(1rem, 2.4vw, 1.8rem);
  --ab-num: var(--font-mono);
  background-color: var(--paper);
  color: var(--ink);
}

.page-about .ab-mono {
  font-family: var(--font-mono);
  letter-spacing: .02em;
}

.page-about .ab-num {
  font-family: var(--ab-num);
  font-weight: 700;
  color: var(--flame);
  font-size: 1.15em;
}

/* ---------- 面包屑 ---------- */
.page-about .breadcrumbs {
  padding-top: 1.1rem;
  padding-bottom: .2rem;
  font-size: .82rem;
  color: var(--muted);
  letter-spacing: .04em;
}

.page-about .breadcrumbs__item {
  color: var(--blue-deep);
  text-decoration: none;
  margin-right: .6rem;
}

.page-about .breadcrumbs__item + .breadcrumbs__item::before {
  content: "/";
  color: var(--line);
  margin-right: .6rem;
}

.page-about .breadcrumbs__item:last-child {
  color: var(--muted);
}

.page-about .breadcrumbs__item:hover {
  text-decoration: underline;
}

/* ---------- 首屏 ---------- */
.page-about .ab-hero {
  position: relative;
  overflow: hidden;
  margin-top: 1rem;
  padding: clamp(2rem, 5.5vw, 4.2rem) 0 clamp(2.2rem, 5vw, 3.6rem);
  color: var(--paper);
  background:
    repeating-linear-gradient(135deg, rgba(247, 245, 239, .045) 0 2px, transparent 2px 15px),
    linear-gradient(148deg, var(--green-deep) 0%, #073a2b 52%, var(--blue-deep) 100%);
  border-bottom: 4px solid var(--flame);
}

.page-about .ab-hero__grid {
  position: absolute;
  inset: 0;
  pointer-events: none;
  background-image:
    repeating-linear-gradient(90deg, rgba(247, 245, 239, .08) 0 1px, transparent 1px 92px),
    repeating-linear-gradient(0deg, rgba(247, 245, 239, .05) 0 1px, transparent 1px 92px);
  -webkit-mask-image: linear-gradient(90deg, rgba(0, 0, 0, .95), transparent 76%);
  mask-image: linear-gradient(90deg, rgba(0, 0, 0, .95), transparent 76%);
}

.page-about .ab-hero__slash {
  position: absolute;
  top: -30%;
  right: 6%;
  width: 130px;
  height: 170%;
  transform: rotate(18deg);
  background: linear-gradient(180deg, rgba(255, 90, 43, .5), rgba(255, 197, 61, .12));
  pointer-events: none;
}

.page-about .ab-hero__inner {
  position: relative;
  z-index: 1;
}

.page-about .ab-hero__kicker {
  margin: 0;
  font-family: var(--font-mono);
  font-size: .82rem;
  letter-spacing: .16em;
  text-transform: uppercase;
  color: var(--yellow);
}

.page-about .ab-hero__title {
  margin: .7rem 0 1.1rem;
  font-family: var(--font-head);
  font-weight: 800;
  font-size: clamp(2.4rem, 6.6vw, 5.2rem);
  line-height: 1.03;
  letter-spacing: -.02em;
}

.page-about .ab-hero__title em {
  display: block;
  font-style: normal;
  color: var(--yellow);
}

.page-about .ab-hero__lede {
  max-width: 60ch;
  margin: 0;
  font-size: clamp(1rem, 1.15vw, 1.12rem);
  line-height: 1.8;
  color: rgba(247, 245, 239, .88);
}

.page-about .ab-hero__stats {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 1px;
  margin-top: clamp(1.6rem, 3.5vw, 2.6rem);
  background-color: rgba(247, 245, 239, .22);
  border: 1px solid rgba(247, 245, 239, .22);
}

.page-about .stat {
  display: flex;
  flex-direction: column;
  gap: .3rem;
  padding: .9rem 1rem;
  background-color: rgba(11, 63, 46, .55);
}

.page-about .stat--accent {
  background-color: var(--flame);
}

.page-about .stat__value {
  font-family: var(--font-mono);
  font-weight: 700;
  font-size: clamp(1.5rem, 3vw, 2.1rem);
  line-height: 1.1;
  color: var(--paper);
}

.page-about .stat__label {
  font-size: .8rem;
  line-height: 1.5;
  color: rgba(247, 245, 239, .82);
}

.page-about .stat--accent .stat__label {
  color: rgba(255, 255, 255, .92);
}

/* ---------- 三栏骨架 ---------- */
.page-about .ab-shell {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: var(--ab-gap);
  padding-top: clamp(1.8rem, 4vw, 3rem);
  padding-bottom: clamp(2.4rem, 6vw, 4.4rem);
}

.page-about .ab-toc {
  padding: .95rem 1rem 1.1rem;
  border: 1px solid var(--line);
  border-top: 4px solid var(--green-mid);
  background-color: #fff;
  box-shadow: var(--shadow-print);
}

.page-about .ab-toc__title {
  margin: 0 0 .7rem;
  font-family: var(--font-mono);
  font-size: .76rem;
  letter-spacing: .18em;
  text-transform: uppercase;
  color: var(--muted);
}

.page-about .ab-toc__list {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: .35rem .9rem;
  margin: 0;
  padding: 0;
  list-style: none;
}

.page-about .ab-toc__link {
  display: flex;
  align-items: baseline;
  gap: .5rem;
  padding: .34rem .4rem;
  color: var(--ink);
  text-decoration: none;
  border-left: 3px solid transparent;
  transition: background-color .18s var(--ease), border-color .18s var(--ease), color .18s var(--ease);
}

.page-about .ab-toc__num {
  font-family: var(--font-mono);
  font-size: .74rem;
  color: var(--green-mid);
}

.page-about .ab-toc__text {
  font-size: .92rem;
  font-weight: 500;
}

.page-about .ab-toc__link:hover,
.page-about .ab-toc__link:focus-visible {
  background-color: rgba(46, 134, 222, .1);
  border-left-color: var(--blue-bright);
}

.page-about .ab-toc__link.is-active,
.page-about .ab-toc__link[aria-current] {
  background-color: var(--flame);
  border-left-color: var(--flame);
  color: #fff;
}

.page-about .ab-toc__link.is-active .ab-toc__num,
.page-about .ab-toc__link[aria-current] .ab-toc__num {
  color: rgba(255, 255, 255, .86);
}

.page-about .ab-toc__note {
  margin: .8rem 0 0;
  font-size: .78rem;
  line-height: 1.6;
  color: var(--muted);
}

/* ---------- 章节 ---------- */
.page-about .ab-flow {
  display: grid;
  gap: clamp(1.6rem, 3.6vw, 2.8rem);
  min-width: 0;
}

.page-about .ab-chapter {
  scroll-margin-top: 110px;
  padding-top: clamp(1.2rem, 2.6vw, 1.8rem);
  border-top: 1px dashed var(--line);
}

.page-about .ab-chapter:first-child {
  border-top: 0;
  padding-top: 0;
}

.page-about .ab-chapter__head {
  display: flex;
  align-items: flex-start;
  gap: .8rem;
  margin-bottom: 1rem;
}

.page-about .ab-chapter__num {
  flex: none;
  margin-top: .3rem;
  padding: .18rem .5rem;
  font-family: var(--font-mono);
  font-size: .86rem;
  font-weight: 700;
  letter-spacing: .08em;
  color: var(--paper);
  background-color: var(--green-deep);
  border-radius: var(--radius);
}

.page-about .ab-chapter__title {
  margin: 0;
  font-family: var(--font-head);
  font-weight: 800;
  font-size: clamp(1.35rem, 2.7vw, 2rem);
  line-height: 1.25;
  letter-spacing: -.01em;
}

.page-about .ab-chapter__body {
  display: grid;
  gap: clamp(1rem, 2.4vw, 1.7rem);
}

.page-about .ab-prose p {
  margin: 0 0 .9rem;
  font-size: 1rem;
  line-height: 1.85;
  color: #1a242b;
}

.page-about .ab-prose p:last-child {
  margin-bottom: 0;
}

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

.page-about .ab-prose a:hover {
  color: var(--flame);
}

/* 角色清单 */
.page-about .ab-roles {
  margin: 0 0 1rem;
  padding: 0;
  list-style: none;
  display: grid;
  gap: .55rem;
}

.page-about .ab-roles__item {
  display: grid;
  gap: .2rem;
  padding: .7rem .85rem;
  border-left: 3px solid var(--green-mid);
  background-color: rgba(30, 155, 114, .07);
}

.page-about .ab-roles__name {
  font-weight: 700;
  font-size: .98rem;
}

.page-about .ab-roles__desc {
  font-size: .92rem;
  line-height: 1.7;
  color: var(--muted);
}

/* 信息块 */
.page-about .ab-fact {
  align-self: start;
  padding: 1rem 1.05rem 1.1rem;
  border: 1px solid var(--line);
  border-left: 4px solid var(--flame);
  background-color: #fff;
  box-shadow: var(--shadow-print);
}

.page-about .ab-fact__label {
  margin: 0 0 .6rem;
  font-family: var(--font-mono);
  font-size: .74rem;
  letter-spacing: .18em;
  text-transform: uppercase;
  color: var(--muted);
}

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

.page-about .ab-fact__row {
  display: flex;
  align-items: baseline;
  justify-content: space-between;
  gap: .8rem;
  padding: .5rem 0;
  border-bottom: 1px solid var(--line-soft);
}

.page-about .ab-fact__row:last-child {
  border-bottom: 0;
}

.page-about .ab-fact__row dt {
  font-size: .88rem;
  color: var(--muted);
}

.page-about .ab-fact__row dd {
  margin: 0;
  font-family: var(--font-mono);
  font-size: .92rem;
  font-weight: 700;
  color: var(--ink);
  text-align: right;
}

.page-about .ab-fact__foot {
  margin: .8rem 0 0;
  font-size: .82rem;
  line-height: 1.65;
  color: var(--muted);
}

.page-about .ab-fact__foot a {
  color: var(--blue-deep);
}

/* ---------- 图 ---------- */
.page-about .ab-shot {
  margin: 0;
  border: 1px solid var(--line);
  background-color: #fff;
}

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

.page-about .ab-shot--a img {
  aspect-ratio: 1000 / 680;
}

.page-about .ab-shot--b img {
  aspect-ratio: 900 / 600;
}

.page-about .ab-shot--c img {
  aspect-ratio: 860 / 600;
}

.page-about .ab-shot figcaption {
  padding: .6rem .85rem;
  font-size: .82rem;
  line-height: 1.6;
  color: var(--muted);
  border-top: 1px solid var(--line);
}

/* ---------- 流程 SVG ---------- */
.page-about .ab-flowmap {
  margin: 0;
  padding: .8rem .6rem .5rem;
  border: 1px solid var(--line);
  background-color: #fff;
  box-shadow: var(--shadow-print);
  overflow-x: auto;
}

.page-about .ab-flowmap svg {
  display: block;
  width: 100%;
  min-width: 560px;
  height: auto;
}

.page-about .ab-flowmap__box {
  fill: rgba(30, 155, 114, .1);
  stroke: var(--green-mid);
  stroke-width: 1.5;
}

.page-about .ab-flowmap__box--final {
  fill: rgba(255, 90, 43, .12);
  stroke: var(--flame);
}

.page-about .ab-flowmap__line {
  stroke: var(--flame);
  stroke-width: 2;
}

.page-about .ab-flowmap__arrow-head {
  fill: var(--flame);
}

.page-about .ab-flowmap__step {
  font-family: var(--font-body);
  font-size: 18px;
  font-weight: 700;
  fill: var(--ink);
  text-anchor: middle;
}

.page-about .ab-flowmap__sub {
  font-family: var(--font-mono);
  font-size: 12px;
  fill: var(--muted);
  text-anchor: middle;
}

.page-about .ab-flowmap figcaption {
  margin-top: .5rem;
  font-size: .82rem;
  line-height: 1.6;
  color: var(--muted);
}

/* ---------- 时间线 ---------- */
.page-about .ab-timeline {
  margin: 0;
  padding: .3rem 0 .3rem 1.7rem;
  list-style: none;
  position: relative;
}

.page-about .ab-timeline::before {
  content: "";
  position: absolute;
  left: .42rem;
  top: .6rem;
  bottom: .9rem;
  width: 2px;
  background: linear-gradient(180deg, var(--green-mid), var(--blue-bright));
}

.page-about .ab-tl__item {
  position: relative;
  padding-bottom: 1.15rem;
}

.page-about .ab-tl__item:last-child {
  padding-bottom: 0;
}

.page-about .ab-tl__item::before {
  content: "";
  position: absolute;
  left: -1.62rem;
  top: .38rem;
  width: .86rem;
  height: .86rem;
  border-radius: 50%;
  background-color: var(--paper);
  border: 2px solid var(--green-mid);
}

.page-about .ab-tl__item--now::before {
  background-color: var(--flame);
  border-color: var(--flame);
  box-shadow: 0 0 0 4px rgba(255, 90, 43, .18);
}

.page-about .ab-tl__ver {
  margin: 0;
  font-family: var(--font-mono);
  font-size: .76rem;
  letter-spacing: .12em;
  color: var(--blue-deep);
}

.page-about .ab-tl__title {
  margin: .12rem 0 .2rem;
  font-size: 1.02rem;
  font-weight: 700;
}

.page-about .ab-tl__desc {
  margin: 0;
  font-size: .92rem;
  line-height: 1.7;
  color: var(--muted);
}

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

/* ---------- 边界 ---------- */
.page-about .ab-bound {
  display: grid;
  gap: .8rem;
}

.page-about .ab-bound details {
  border: 1px solid var(--line);
  background-color: #fff;
  box-shadow: var(--shadow-print);
}

.page-about .ab-bound summary {
  display: flex;
  align-items: center;
  gap: .7rem;
  padding: .85rem 1rem;
  font-weight: 700;
  font-size: .98rem;
  cursor: pointer;
  list-style: none;
}

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

.page-about .ab-bound summary::after {
  content: "+";
  margin-left: auto;
  font-family: var(--font-mono);
  font-size: 1.1rem;
  color: var(--green-mid);
}

.page-about .ab-bound details[open] summary::after {
  content: "−";
  color: var(--flame);
}

.page-about .ab-bound details[open] summary {
  border-bottom: 1px dashed var(--line);
}

.page-about .ab-bound summary:focus-visible {
  outline: 2px solid var(--blue-bright);
  outline-offset: -2px;
}

.page-about .ab-bound__tag {
  flex: none;
  padding: .14rem .45rem;
  font-family: var(--font-mono);
  font-size: .7rem;
  letter-spacing: .12em;
  color: #fff;
  background-color: var(--flame);
  border-radius: var(--radius);
}

.page-about .ab-bound__body {
  padding: .8rem 1rem 1rem;
}

.page-about .ab-bound__body p {
  margin: 0;
  font-size: .94rem;
  line-height: 1.8;
  color: var(--muted);
}

/* ---------- 联系 ---------- */
.page-about .ab-contact {
  align-self: start;
  padding: 1rem 1.05rem 1.1rem;
  border: 1px solid var(--line);
  border-top: 4px solid var(--blue-deep);
  background-color: #fff;
  box-shadow: var(--shadow-print);
}

.page-about .ab-contact__label {
  margin: 0 0 .7rem;
  font-family: var(--font-mono);
  font-size: .74rem;
  letter-spacing: .18em;
  text-transform: uppercase;
  color: var(--muted);
}

.page-about .ab-contact__item {
  display: grid;
  gap: .15rem;
  margin: 0 0 .7rem;
}

.page-about .ab-contact__key {
  font-size: .78rem;
  color: var(--green-deep);
  letter-spacing: .06em;
}

.page-about .ab-contact__val {
  font-size: .92rem;
  line-height: 1.65;
  word-break: break-word;
  color: var(--ink);
}

.page-about .ab-contact__note {
  margin: .8rem 0 .9rem;
  padding-top: .8rem;
  font-size: .8rem;
  line-height: 1.65;
  color: var(--muted);
  border-top: 1px dashed var(--line);
}

.page-about .ab-contact .btn {
  display: inline-block;
}

/* ---------- 继续看 ---------- */
.page-about .ab-next {
  margin-top: clamp(1rem, 3vw, 2rem);
  padding: clamp(1.2rem, 3vw, 2rem);
  border: 1px solid var(--line);
  border-left: 6px solid var(--green-deep);
  background:
    repeating-linear-gradient(135deg, rgba(30, 155, 114, .07) 0 2px, transparent 2px 14px),
    #fff;
}

.page-about .ab-next__title {
  margin: 0 0 .5rem;
  font-family: var(--font-head);
  font-weight: 800;
  font-size: clamp(1.15rem, 2.2vw, 1.5rem);
}

.page-about .ab-next__desc {
  margin: 0 0 1rem;
  font-size: .95rem;
  line-height: 1.75;
  color: var(--muted);
}

.page-about .ab-next__links {
  display: flex;
  flex-wrap: wrap;
  gap: .6rem;
}

/* ---------- 响应式 ---------- */
@media (min-width: 700px) {
  .page-about .ab-hero__stats {
    grid-template-columns: repeat(4, minmax(0, 1fr));
  }

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

  .page-about .ab-chapter__body--split {
    grid-template-columns: minmax(0, 1.65fr) minmax(0, 1fr);
  }
}

@media (min-width: 1000px) {
  .page-about .ab-shell {
    grid-template-columns: 216px minmax(0, 1fr);
    gap: clamp(1.6rem, 3vw, 2.8rem);
    align-items: start;
  }

  .page-about .ab-toc {
    position: sticky;
    top: 108px;
  }

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

@media (prefers-reduced-motion: reduce) {
  .page-about .ab-toc__link {
    transition: none;
  }

  .page-about .reveal {
    opacity: 1;
    transform: none;
  }
}
<<<END>>>