.page-about {
  --ab-line: #D8D2C4;
  --ab-body: #2C3A4B;
  --ab-body-soft: #3D4C5D;
  background: var(--paper);
  color: var(--ink);
}

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

.page-about .num {
  font-family: var(--font-mono);
  letter-spacing: 0.04em;
}

/* ---------- 首屏 ---------- */

.page-about .ab-hero {
  position: relative;
  overflow: hidden;
  background: var(--ink);
  color: var(--text-on-ink);
  padding: 28px 0 56px;
}

.page-about .ab-hero::after {
  content: "";
  position: absolute;
  inset: 0;
  background-image:
    linear-gradient(to right, rgba(36, 56, 79, 0.55) 1px, transparent 1px),
    linear-gradient(to bottom, rgba(36, 56, 79, 0.55) 1px, transparent 1px);
  background-size: 88px 88px;
  pointer-events: none;
  opacity: 0.7;
}

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

.page-about .ab-crumb {
  font-family: var(--font-mono);
  font-size: 0.72rem;
  letter-spacing: 0.06em;
  margin-bottom: 30px;
}

.page-about .ab-crumb ol {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  margin: 0;
  padding: 0;
  list-style: none;
}

.page-about .ab-crumb li {
  display: inline-flex;
  align-items: center;
  color: var(--cool);
}

.page-about .ab-crumb li + li {
  margin-left: 8px;
}

.page-about .ab-crumb li + li::before {
  content: "/";
  margin-right: 8px;
  color: var(--rule);
}

.page-about .ab-crumb a {
  color: var(--gold);
  text-decoration: none;
  transition: color 150ms var(--ease);
}

.page-about .ab-crumb a:hover,
.page-about .ab-crumb a:focus-visible {
  color: var(--gold-lite);
  text-decoration: underline;
  text-underline-offset: 3px;
}

.page-about .ab-hero__grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: 34px;
}

.page-about .ab-hero h1 {
  font-family: var(--font-serif);
  font-weight: 700;
  font-size: 1.9rem;
  line-height: 1.2;
  letter-spacing: -0.01em;
  color: var(--text-on-ink-strong);
  margin: 12px 0 18px;
}

.page-about .ab-hero__intro {
  margin: 0;
  font-size: 0.98rem;
  line-height: 1.85;
  color: var(--text-on-ink);
}

.page-about .ab-hero__stats {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 1px;
  background: var(--rule);
  border: 1px solid var(--rule);
}

.page-about .ab-stat {
  display: flex;
  flex-direction: column;
  gap: 6px;
  background: var(--ink-up);
  padding: 18px 16px;
}

.page-about .ab-stat__v {
  display: flex;
  align-items: baseline;
  gap: 6px;
  font-family: var(--font-mono);
  font-size: 1.5rem;
  font-weight: 700;
  line-height: 1;
  color: var(--gold-lite);
  letter-spacing: -0.01em;
}

.page-about .ab-stat__v em {
  font-style: normal;
  font-size: 0.72rem;
  font-weight: 500;
  color: var(--gold);
  letter-spacing: 0.02em;
}

.page-about .ab-stat__l {
  font-size: 0.78rem;
  line-height: 1.55;
  color: var(--cool);
}

/* ---------- 主体两栏 ---------- */

.page-about .ab-body-wrap {
  background: var(--sand);
  padding: 40px 0 64px;
}

.page-about .ab-body {
  display: grid;
  grid-template-columns: 1fr;
  gap: 30px;
}

/* 左侧索引 */

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

.page-about .ab-rail__cap {
  margin: 0 0 12px;
  font-family: var(--font-mono);
  font-size: 0.7rem;
  letter-spacing: 0.16em;
  color: var(--gold-dark);
}

.page-about .ab-rail__list {
  display: flex;
  gap: 8px;
  margin: 0;
  padding: 0 0 6px;
  list-style: none;
  overflow-x: auto;
  scrollbar-width: thin;
}

.page-about .ab-rail__item {
  flex: 0 0 auto;
}

.page-about .ab-rail__link {
  display: inline-flex;
  align-items: baseline;
  gap: 8px;
  padding: 8px 12px;
  border: 1px solid var(--ab-line);
  background: var(--paper);
  font-size: 0.82rem;
  line-height: 1.4;
  color: #4A5766;
  text-decoration: none;
  white-space: nowrap;
  transition: border-color 150ms var(--ease), color 150ms var(--ease), background-color 150ms var(--ease);
}

.page-about .ab-rail__link:hover,
.page-about .ab-rail__link:focus-visible {
  border-color: var(--gold);
  color: var(--ink);
  background: #FBF8F1;
}

.page-about .ab-rail__n {
  font-size: 0.7rem;
  color: var(--gold-dark);
}

/* ---------- 档案卡 ---------- */

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

.page-about .ab-card {
  position: relative;
  background: var(--paper);
  border: 1px solid var(--ab-line);
  border-radius: 0;
  padding: 26px 20px 26px;
  margin-bottom: 24px;
  box-shadow: 4px 4px 0 rgba(216, 210, 196, 0.6), var(--shadow-lift);
  scroll-margin-top: calc(var(--header-h) + 24px);
}

.page-about .ab-card::before {
  content: "";
  position: absolute;
  left: -1px;
  top: 26px;
  width: 3px;
  height: 42px;
  background: linear-gradient(180deg, var(--gold-lite), var(--gold-dark));
}

.page-about .ab-card__head {
  padding-bottom: 16px;
  border-bottom: 1px solid var(--ab-line);
  margin-bottom: 20px;
}

.page-about .ab-card__n {
  display: block;
  margin-bottom: 8px;
  font-size: 0.72rem;
  letter-spacing: 0.18em;
  color: var(--gold-dark);
}

.page-about .ab-card__title {
  margin: 0 0 8px;
  font-family: var(--font-serif);
  font-weight: 600;
  font-size: 1.35rem;
  line-height: 1.25;
  color: var(--ink);
}

.page-about .ab-card__lead {
  margin: 0;
  font-size: 0.9rem;
  line-height: 1.72;
  color: var(--cool);
}

.page-about .ab-card__body p {
  margin: 0 0 1em;
  font-size: 0.96rem;
  line-height: 1.85;
  color: var(--ab-body);
}

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

.page-about .ab-card__body a {
  color: var(--gold-dark);
  text-decoration: underline;
  text-underline-offset: 3px;
  text-decoration-thickness: 1px;
  transition: color 150ms var(--ease);
}

.page-about .ab-card__body a:hover,
.page-about .ab-card__body a:focus-visible {
  color: var(--ink);
}

/* 折叠 */

.page-about .ab-more {
  margin-top: 18px;
  padding-top: 14px;
  border-top: 1px dashed var(--ab-line);
}

.page-about .ab-more > summary {
  display: inline-flex;
  align-items: center;
  gap: 9px;
  padding: 4px 0;
  cursor: pointer;
  list-style: none;
  font-family: var(--font-mono);
  font-size: 0.77rem;
  letter-spacing: 0.06em;
  color: var(--gold-dark);
  transition: color 150ms var(--ease);
}

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

.page-about .ab-more > summary::before {
  content: "";
  width: 0;
  height: 0;
  border-left: 6px solid currentColor;
  border-top: 4.5px solid transparent;
  border-bottom: 4.5px solid transparent;
  transition: transform 150ms var(--ease);
}

.page-about .ab-more[open] > summary::before {
  transform: rotate(90deg);
}

.page-about .ab-more > summary:hover,
.page-about .ab-more > summary:focus-visible {
  color: var(--ink);
}

.page-about .ab-more__body {
  padding-top: 12px;
}

.page-about .ab-more__body p {
  margin: 0 0 1em;
  font-size: 0.92rem;
  line-height: 1.85;
  color: var(--ab-body-soft);
}

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

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

/* ---------- 类目网格 ---------- */

.page-about .ab-cats {
  counter-reset: ab-cat;
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 1px;
  margin: 4px 0 0;
  padding: 0;
  list-style: none;
  background: var(--ab-line);
  border: 1px solid var(--ab-line);
}

.page-about .ab-cat {
  display: flex;
  flex-direction: column;
  gap: 5px;
  padding: 13px 12px;
  background: var(--paper);
  transition: background-color 150ms var(--ease);
}

.page-about .ab-cat:hover,
.page-about .ab-cat:focus-within {
  background: #FBF8F1;
  outline: 1px solid var(--gold);
  outline-offset: -1px;
}

.page-about .ab-cat__n {
  font-family: var(--font-mono);
  font-size: 0.68rem;
  letter-spacing: 0.12em;
  color: var(--gold-dark);
}

.page-about .ab-cat__n::before {
  counter-increment: ab-cat;
  content: counter(ab-cat, decimal-leading-zero);
}

.page-about .ab-cat__name {
  font-size: 0.9rem;
  font-weight: 500;
  line-height: 1.35;
  color: var(--ink);
}

.page-about .ab-cat__desc {
  font-size: 0.74rem;
  line-height: 1.55;
  color: var(--cool);
}

/* ---------- 四项规则 ---------- */

.page-about .ab-rules {
  display: grid;
  grid-template-columns: 1fr;
  gap: 1px;
  margin-top: 4px;
  background: var(--ab-line);
  border: 1px solid var(--ab-line);
}

.page-about .ab-rule {
  padding: 17px 15px;
  background: var(--sand);
}

.page-about .ab-rule__t {
  display: flex;
  align-items: baseline;
  gap: 8px;
  margin: 0 0 8px;
  font-family: var(--font-serif);
  font-weight: 600;
  font-size: 1.05rem;
  color: var(--ink);
}

.page-about .ab-rule__t::before {
  content: "";
  flex: none;
  width: 6px;
  height: 6px;
  background: var(--gold);
  transform: translateY(-2px);
}

.page-about .ab-rule__d {
  margin: 0;
  font-size: 0.86rem;
  line-height: 1.78;
  color: var(--ab-body-soft);
}

.page-about .ab-rule__d .num {
  color: var(--ink);
  font-weight: 600;
}

/* ---------- 授权版图 ---------- */

.page-about .ab-card--map {
  padding-bottom: 28px;
}

.page-about .ab-map-grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: 22px;
  margin-bottom: 22px;
}

.page-about .ab-map__svg {
  display: block;
  width: 100%;
  height: auto;
  padding: 10px;
  background: var(--ink-up);
  border: 1px solid var(--rule);
}

.page-about .ab-map__zone rect {
  fill: rgba(201, 162, 39, 0.1);
  stroke: rgba(201, 162, 39, 0.5);
  stroke-width: 1;
  transition: fill 150ms var(--ease), stroke 150ms var(--ease);
}

.page-about .ab-map__zone:hover rect {
  fill: rgba(201, 162, 39, 0.24);
  stroke: var(--gold);
}

.page-about .ab-map__zone text {
  font-family: var(--font-sans);
  font-size: 15px;
  letter-spacing: 0.08em;
  fill: var(--text-on-ink-strong);
  text-anchor: middle;
}

.page-about .ab-legend {
  margin: 12px 0 0;
  padding: 0;
  list-style: none;
  display: flex;
  flex-direction: column;
  gap: 8px;
}

.page-about .ab-legend__i {
  display: flex;
  align-items: flex-start;
  gap: 9px;
  font-size: 0.78rem;
  line-height: 1.6;
  color: var(--cool);
}

.page-about .ab-legend__s {
  flex: none;
  width: 12px;
  height: 12px;
  margin-top: 3px;
  border: 1px solid transparent;
}

.page-about .ab-legend__s--gold {
  background: rgba(201, 162, 39, 0.22);
  border-color: var(--gold);
}

.page-about .ab-legend__s--red {
  background: rgba(178, 58, 46, 0.16);
  border-color: var(--red);
}

/* ---------- 团队 ---------- */

.page-about .ab-team {
  display: flex;
  flex-direction: column;
  gap: 1px;
  margin-top: 4px;
  background: var(--ab-line);
  border: 1px solid var(--ab-line);
}

.page-about .ab-team__row {
  display: grid;
  grid-template-columns: 1fr auto;
  gap: 4px 12px;
  padding: 16px 14px;
  background: var(--paper);
}

.page-about .ab-team__role {
  font-family: var(--font-serif);
  font-size: 1rem;
  font-weight: 600;
  color: var(--ink);
}

.page-about .ab-team__count {
  font-size: 1.2rem;
  font-weight: 700;
  line-height: 1.2;
  color: var(--gold-dark);
  text-align: right;
}

.page-about .ab-team__duty {
  grid-column: 1 / -1;
  margin: 0;
  font-size: 0.85rem;
  line-height: 1.75;
  color: var(--ab-body-soft);
}

/* ---------- 更新节奏 ---------- */

.page-about .ab-cycle {
  margin: 4px 0 0;
  padding: 0;
  list-style: none;
  border-left: 1px solid var(--ab-line);
}

.page-about .ab-cycle__i {
  position: relative;
  padding: 0 0 18px 22px;
}

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

.page-about .ab-cycle__i::before {
  content: "";
  position: absolute;
  left: -5px;
  top: 6px;
  width: 9px;
  height: 9px;
  border-radius: 50%;
  background: var(--sand);
  border: 1px solid var(--gold);
}

.page-about .ab-cycle__when {
  display: block;
  margin-bottom: 5px;
  font-family: var(--font-mono);
  font-size: 0.76rem;
  letter-spacing: 0.1em;
  color: var(--gold-dark);
}

.page-about .ab-cycle__what {
  margin: 0;
  font-size: 0.9rem;
  line-height: 1.8;
  color: var(--ab-body-soft);
}

.page-about .ab-cycle__what .num {
  color: var(--ink);
  font-weight: 600;
}

/* ---------- 主体信息 ---------- */

.page-about .ab-legal {
  display: flex;
  flex-direction: column;
  gap: 1px;
  margin-top: 4px;
  background: var(--ab-line);
  border: 1px solid var(--ab-line);
}

.page-about .ab-legal__row {
  display: flex;
  flex-wrap: wrap;
  gap: 4px 14px;
  padding: 12px 14px;
  background: var(--paper);
}

.page-about .ab-legal__k {
  flex: 0 0 auto;
  min-width: 84px;
  font-size: 0.8rem;
  line-height: 1.6;
  color: var(--cool);
}

.page-about .ab-legal__v {
  font-size: 0.88rem;
  line-height: 1.6;
  color: var(--ink);
  word-break: break-word;
}

.page-about .ab-legal__note {
  margin: 12px 0 0;
  font-size: 0.78rem;
  line-height: 1.7;
  color: var(--cool);
}

.page-about .ab-legal__note .num {
  color: var(--ink);
}

/* ---------- 延伸入口 ---------- */

.page-about .ab-next {
  margin-top: 8px;
  padding: 22px 20px;
  background: var(--ink);
  border: 1px solid var(--rule);
}

.page-about .ab-next__cap {
  margin: 0 0 14px;
  font-family: var(--font-mono);
  font-size: 0.7rem;
  letter-spacing: 0.16em;
  color: var(--gold);
}

.page-about .ab-next__list {
  display: grid;
  grid-template-columns: 1fr;
  gap: 1px;
  margin: 0;
  padding: 0;
  list-style: none;
  background: var(--rule);
}

.page-about .ab-next__link {
  display: flex;
  flex-direction: column;
  gap: 5px;
  padding: 14px 14px;
  background: var(--ink-up);
  text-decoration: none;
  transition: background-color 150ms var(--ease), box-shadow 150ms var(--ease);
}

.page-about .ab-next__link:hover,
.page-about .ab-next__link:focus-visible {
  background: #1B2E46;
  box-shadow: inset 3px 0 0 var(--gold);
}

.page-about .ab-next__t {
  font-family: var(--font-serif);
  font-size: 1rem;
  font-weight: 600;
  color: var(--text-on-ink-strong);
}

.page-about .ab-next__d {
  font-size: 0.78rem;
  line-height: 1.6;
  color: var(--cool);
}

/* ---------- 图片兜底 ---------- */

.page-about .figure {
  margin: 22px 0 0;
}

.page-about .figure__frame {
  overflow: hidden;
  border: 1px solid var(--ab-line);
}

.page-about .figure__img {
  display: block;
  width: 100%;
  height: auto;
  object-fit: cover;
  filter: saturate(0.9);
}

.page-about .figure__cap {
  margin: 10px 0 0;
  font-size: 0.76rem;
  line-height: 1.65;
  color: var(--cool);
}

/* ---------- 断点 ---------- */

@media (min-width: 640px) {
  .page-about .ab-hero {
    padding: 34px 0 68px;
  }

  .page-about .ab-hero h1 {
    font-size: 2.4rem;
  }

  .page-about .ab-hero__intro {
    font-size: 1.05rem;
    max-width: 56ch;
  }

  .page-about .ab-hero__stats {
    grid-template-columns: repeat(4, minmax(0, 1fr));
  }

  .page-about .ab-body-wrap {
    padding: 56px 0 80px;
  }

  .page-about .ab-card {
    padding: 32px 30px 30px;
    margin-bottom: 28px;
  }

  .page-about .ab-card__title {
    font-size: 1.55rem;
  }

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

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

  .page-about .ab-next {
    padding: 26px 28px;
  }

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

@media (min-width: 1024px) {
  .page-about .ab-hero {
    padding: 40px 0 84px;
  }

  .page-about .ab-hero__grid {
    grid-template-columns: minmax(0, 5fr) minmax(0, 7fr);
    gap: 60px;
    align-items: end;
  }

  .page-about .ab-hero h1 {
    font-size: 3rem;
    margin: 14px 0 22px;
  }

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

  .page-about .ab-stat {
    padding: 22px 20px;
  }

  .page-about .ab-stat__v {
    font-size: 1.75rem;
  }

  .page-about .ab-body-wrap {
    padding: 72px 0 96px;
  }

  .page-about .ab-body {
    grid-template-columns: 210px minmax(0, 1fr);
    gap: 56px;
    align-items: start;
  }

  .page-about .ab-rail {
    position: sticky;
    top: calc(var(--header-h) + 28px);
  }

  .page-about .ab-rail__list {
    display: block;
    overflow: visible;
    padding: 0;
  }

  .page-about .ab-rail__item {
    margin-bottom: 0;
  }

  .page-about .ab-rail__link {
    display: flex;
    align-items: baseline;
    gap: 10px;
    padding: 7px 0 7px 24px;
    border: 0;
    background: transparent;
    font-size: 0.85rem;
    white-space: normal;
  }

  .page-about .ab-rail__link:hover,
  .page-about .ab-rail__link:focus-visible {
    background: transparent;
    box-shadow: none;
  }

  .page-about .ab-rail__link::before {
    content: "";
    position: absolute;
    left: 1px;
    top: 0.85em;
    width: 11px;
    height: 11px;
    border-radius: 50%;
    background: var(--sand);
    border: 1px solid var(--ab-line);
    transition: background-color 150ms var(--ease), border-color 150ms var(--ease), transform 150ms var(--ease);
  }

  .page-about .ab-rail__link:hover::before,
  .page-about .ab-rail__link:focus-visible::before {
    background: var(--gold);
    border-color: var(--gold);
    transform: scale(1.18);
  }

  .page-about .ab-rail__list::after {
    content: "";
    position: absolute;
    left: 6px;
    top: 14px;
    bottom: 14px;
    width: 1px;
    background: var(--ab-line);
    z-index: -1;
  }

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

  .page-about .ab-card {
    padding: 38px 44px 36px;
    margin-bottom: 32px;
  }

  .page-about .ab-card::before {
    top: 38px;
  }

  .page-about .ab-map-grid {
    grid-template-columns: minmax(0, 0.85fr) minmax(0, 1.15fr);
    gap: 30px;
    align-items: start;
  }

  .page-about .ab-card__body p {
    font-size: 1rem;
  }

  .page-about .ab-next__list {
    grid-template-columns: repeat(4, minmax(0, 1fr));
  }
}

@media (min-width: 1280px) {
  .page-about .ab-hero h1 {
    font-size: 3.4rem;
  }

  .page-about .ab-stat__v {
    font-size: 1.9rem;
  }

  .page-about .ab-cats {
    grid-template-columns: repeat(4, minmax(0, 1fr));
  }
}