.page-about {
  --ab-gold-soft: rgba(201, 162, 75, 0.12);
  --ab-grid: rgba(127, 166, 160, 0.10);
  padding-bottom: var(--sp-7);
}

.page-about .breadcrumbs {
  padding-top: var(--sp-3);
  padding-bottom: var(--sp-2);
}

/* ---------- 首屏 ---------- */
.page-about .ab-hero {
  position: relative;
  padding: var(--sp-4) 0 0;
  overflow: hidden;
  background:
    radial-gradient(120% 90% at 84% 0%, rgba(201, 162, 75, 0.14), transparent 62%),
    linear-gradient(180deg, rgba(28, 34, 31, 0) 0%, rgba(28, 34, 31, 0.55) 100%);
  border-bottom: 1px solid var(--line);
}

.page-about .ab-hero::before {
  content: "";
  position: absolute;
  inset: 0;
  background-image:
    linear-gradient(to right, var(--ab-grid) 1px, transparent 1px),
    linear-gradient(to bottom, var(--ab-grid) 1px, transparent 1px);
  background-size: 96px 96px;
  -webkit-mask-image: radial-gradient(120% 80% at 70% 0%, #000 20%, transparent 82%);
  mask-image: radial-gradient(120% 80% at 70% 0%, #000 20%, transparent 82%);
  pointer-events: none;
}

.page-about .ab-hero__grid {
  position: relative;
  z-index: 1;
  display: grid;
  gap: var(--sp-4);
}

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

.page-about .ab-kicker {
  margin: 0 0 var(--sp-2);
  font-size: 11px;
  letter-spacing: 0.22em;
  color: var(--gold);
  text-transform: uppercase;
}

.page-about .ab-hero__title {
  margin: 0 0 var(--sp-3);
  font-family: var(--font-display);
  font-weight: 800;
  font-size: clamp(28px, 6vw, 50px);
  line-height: 1.18;
  letter-spacing: -0.02em;
  color: var(--paper);
}

.page-about .ab-hero__lede {
  margin: 0 0 var(--sp-2);
  font-size: 16px;
  line-height: 1.75;
  color: var(--txt);
  max-width: 48ch;
}

.page-about .ab-hero__sub {
  margin: 0;
  font-size: 14px;
  line-height: 1.8;
  color: var(--txt-dim);
  max-width: 52ch;
  padding-left: var(--sp-2);
  border-left: 1px solid var(--gold-line);
}

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

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

/* ---------- 台账条 ---------- */
.page-about .ab-ledger {
  position: relative;
  z-index: 1;
  list-style: none;
  margin: var(--sp-5) 0 0;
  padding: 0;
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  border-top: 1px solid var(--line-strong);
}

.page-about .ab-ledger__item {
  display: flex;
  flex-direction: column;
  gap: 4px;
  padding: 16px 12px 18px 0;
  border-bottom: 1px solid var(--line-soft);
}

.page-about .ab-ledger__num {
  font-size: 26px;
  line-height: 1;
  color: var(--gold-lt);
  font-variant-numeric: tabular-nums;
}

.page-about .ab-ledger__unit {
  font-size: 13px;
  margin-left: 2px;
  color: var(--txt-dim);
}

.page-about .ab-ledger__label {
  font-size: 12px;
  letter-spacing: 0.04em;
  color: var(--txt-dim);
}

/* ---------- 主体两栏 ---------- */
.page-about .ab-body {
  display: grid;
  gap: var(--sp-5);
  margin-top: var(--sp-6);
}

/* ---------- 目录索引 ---------- */
.page-about .ab-index__title {
  margin: 0 0 10px;
  font-size: 11px;
  letter-spacing: 0.2em;
  color: var(--txt-dim);
  text-transform: uppercase;
}

.page-about .ab-index__list {
  list-style: none;
  margin: 0;
  padding: 0;
  display: flex;
  flex-wrap: wrap;
  gap: 2px 18px;
}

.page-about .ab-index__link {
  display: flex;
  align-items: center;
  gap: 8px;
  padding: 7px 0 7px 10px;
  border-left: 1px solid var(--line-soft);
  font-size: 13px;
  color: var(--txt-dim);
  text-decoration: none;
  transition: color var(--dur) var(--ease), border-color var(--dur) var(--ease), background-color var(--dur) var(--ease);
}

.page-about .ab-index__link .mono {
  font-size: 10px;
  letter-spacing: 0.08em;
  color: var(--gold);
  opacity: 0.75;
}

.page-about .ab-index__link:hover {
  color: var(--paper);
  border-left-color: var(--gold-line);
}

.page-about .ab-index__link[aria-current="true"] {
  color: var(--gold-lt);
  border-left-color: var(--gold);
  background: linear-gradient(90deg, var(--ab-gold-soft), transparent 78%);
}

/* ---------- 章节 ---------- */
.page-about .ab-chapter {
  padding-top: var(--sp-5);
  border-top: 1px solid var(--line-soft);
}

.page-about .ab-chapters > .ab-chapter:first-child {
  padding-top: 0;
  border-top: none;
}

.page-about .ab-chapter__head {
  display: flex;
  align-items: baseline;
  flex-wrap: wrap;
  gap: 6px 16px;
  margin-bottom: var(--sp-3);
}

.page-about .ab-chapter__code {
  font-size: 40px;
  line-height: 1;
  letter-spacing: -0.05em;
  color: rgba(201, 162, 75, 0.16);
  -webkit-text-stroke: 1px rgba(201, 162, 75, 0.55);
  font-variant-numeric: tabular-nums;
}

.page-about .ab-chapter__title {
  margin: 0;
  font-family: var(--font-display);
  font-weight: 700;
  font-size: clamp(21px, 3.4vw, 30px);
  line-height: 1.35;
  letter-spacing: -0.01em;
  color: var(--paper);
}

.page-about .ab-chapter__grid {
  display: grid;
  gap: var(--sp-3);
}

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

.page-about .ab-chapter__text.prose p {
  margin-top: 0;
  margin-bottom: var(--sp-2);
}

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

.page-about .ab-chapter__text.prose a {
  color: var(--gold-lt);
  text-decoration: underline;
  text-decoration-color: var(--gold-line);
  text-underline-offset: 3px;
}

.page-about .ab-chapter__text.prose a:hover {
  color: var(--paper);
  text-decoration-color: var(--gold);
}

/* ---------- 旁注面板 ---------- */
.page-about .ab-note {
  padding: var(--sp-3);
  min-width: 0;
}

.page-about .ab-note .panel__head {
  margin: 0 0 12px;
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: 0.16em;
  color: var(--gold);
  text-transform: uppercase;
}

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

.page-about .ab-note li {
  position: relative;
  padding-left: 16px;
  font-size: 14px;
  line-height: 1.65;
  color: var(--txt);
}

.page-about .ab-note li::before {
  content: "";
  position: absolute;
  left: 0;
  top: 0.72em;
  width: 7px;
  height: 1px;
  background: var(--gold);
}

/* ---------- 图片 ---------- */
.page-about .ab-figure {
  margin: 0 0 var(--sp-4);
  border: 1px solid var(--line);
  background: var(--ink-3);
}

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

.page-about .ab-figure .media__caption {
  padding: 8px 12px;
  font-size: 11px;
  letter-spacing: 0.1em;
  color: var(--txt-dim);
  border-top: 1px solid var(--line-soft);
}

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

/* ---------- 时间轴 ---------- */
.page-about .ab-timeline {
  position: relative;
  list-style: none;
  margin: 0;
  padding: 0 0 0 24px;
}

.page-about .ab-timeline::before {
  content: "";
  position: absolute;
  left: 5px;
  top: 8px;
  bottom: 12px;
  width: 1px;
  background: linear-gradient(to bottom, var(--gold-line), rgba(127, 166, 160, 0.18));
}

.page-about .ab-node {
  position: relative;
  padding-bottom: var(--sp-4);
}

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

.page-about .ab-node::before {
  content: "";
  position: absolute;
  left: -23px;
  top: 6px;
  width: 7px;
  height: 7px;
  transform: rotate(45deg);
  border: 1px solid var(--gold);
  background: var(--ink);
}

.page-about .ab-node__meta {
  margin: 0 0 6px;
  font-size: 11px;
  letter-spacing: 0.14em;
  color: var(--gold);
  text-transform: uppercase;
}

.page-about .ab-node__title {
  margin: 0 0 8px;
  font-family: var(--font-display);
  font-weight: 700;
  font-size: 18px;
  line-height: 1.45;
  color: var(--paper);
}

.page-about .ab-node__text {
  margin: 0;
  font-size: 14px;
  line-height: 1.8;
  color: var(--txt);
  max-width: 66ch;
}

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

/* ---------- 权益色带 ---------- */
.page-about .ab-tiers {
  margin-top: var(--sp-4);
  border-bottom: 1px solid var(--line-soft);
}

.page-about .ab-tier {
  border-top: 1px solid var(--line-soft);
}

.page-about .ab-tier--1 { --bar-w: 4px; --bar-c: var(--gold); }
.page-about .ab-tier--2 { --bar-w: 6px; --bar-c: var(--gold-lt); }
.page-about .ab-tier--3 { --bar-w: 8px; --bar-c: var(--mint); }
.page-about .ab-tier--4 { --bar-w: 10px; --bar-c: var(--jade); }

.page-about .ab-tier__sum {
  display: grid;
  grid-template-columns: var(--bar-w) minmax(0, 1fr) 22px;
  grid-template-areas:
    "bar name sign"
    "bar fit sign";
  column-gap: 14px;
  row-gap: 5px;
  padding: 16px 6px 16px 0;
  list-style: none;
  cursor: pointer;
  transition: background-color var(--dur) var(--ease);
}

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

.page-about .ab-tier__sum:hover {
  background-color: rgba(127, 166, 160, 0.05);
}

.page-about .ab-tier__bar {
  grid-area: bar;
  background: var(--bar-c);
  align-self: stretch;
  min-height: 24px;
}

.page-about .ab-tier__name {
  grid-area: name;
  font-family: var(--font-display);
  font-weight: 700;
  font-size: 19px;
  line-height: 1.3;
  color: var(--paper);
}

.page-about .ab-tier__fit {
  grid-area: fit;
  font-size: 13px;
  line-height: 1.6;
  color: var(--txt-dim);
}

.page-about .ab-tier__sign {
  grid-area: sign;
  position: relative;
  align-self: center;
  justify-self: center;
  width: 14px;
  height: 14px;
}

.page-about .ab-tier__sign::before,
.page-about .ab-tier__sign::after {
  content: "";
  position: absolute;
  left: 0;
  top: 50%;
  width: 14px;
  height: 1px;
  background: var(--gold);
  transition: transform var(--dur) var(--ease), opacity var(--dur) var(--ease);
}

.page-about .ab-tier__sign::after {
  transform: rotate(90deg);
}

.page-about .ab-tier[open] .ab-tier__sign::after {
  transform: rotate(0deg);
  opacity: 0;
}

.page-about .ab-tier__body {
  padding: 0 6px 20px calc(var(--bar-w) + 14px);
}

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

.page-about .ab-tier__body li {
  position: relative;
  padding-left: 15px;
  font-size: 14px;
  line-height: 1.75;
  color: var(--txt);
}

.page-about .ab-tier__body li::before {
  content: "·";
  position: absolute;
  left: 3px;
  color: var(--gold);
}

.page-about .ab-tiers__after {
  margin-top: var(--sp-3);
}

/* ---------- 团队 ---------- */
.page-about .ab-team {
  display: grid;
  gap: var(--sp-4);
}

.page-about .ab-team .ab-figure {
  order: -1;
  margin-bottom: 0;
}

.page-about .ab-roles {
  list-style: none;
  margin: var(--sp-3) 0 0;
  padding: 0;
  display: grid;
  border-bottom: 1px solid var(--line-soft);
}

.page-about .ab-roles li {
  display: grid;
  gap: 4px;
  padding: 14px 0;
  border-top: 1px solid var(--line-soft);
}

.page-about .ab-roles strong {
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.12em;
  font-weight: 500;
  color: var(--gold-lt);
}

.page-about .ab-roles span {
  font-size: 14px;
  line-height: 1.75;
  color: var(--txt-dim);
}

/* ---------- 资质定义表 ---------- */
.page-about .ab-def {
  margin: var(--sp-3) 0 0;
  padding: 0;
  display: grid;
  border-bottom: 1px solid var(--line-soft);
}

.page-about .ab-def > div {
  display: grid;
  gap: 4px;
  padding: 14px 0;
  border-top: 1px solid var(--line-soft);
}

.page-about .ab-def dt {
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: 0.14em;
  color: var(--txt-dim);
  text-transform: uppercase;
}

.page-about .ab-def dd {
  margin: 0;
  font-size: 15px;
  line-height: 1.7;
  color: var(--paper);
}

.page-about .ab-def dd.mono {
  font-family: var(--font-mono);
  letter-spacing: 0.04em;
  color: var(--gold-lt);
  font-variant-numeric: tabular-nums;
}

/* ---------- 生态数字 ---------- */
.page-about .ab-eco {
  display: grid;
  gap: var(--sp-3);
  margin-top: var(--sp-4);
}

.page-about .ab-eco__cell {
  padding-top: 14px;
  border-top: 1px solid var(--gold-line);
  min-width: 0;
}

.page-about .ab-eco__num {
  display: block;
  font-size: 34px;
  line-height: 1;
  color: var(--gold-lt);
  font-variant-numeric: tabular-nums;
}

.page-about .ab-eco__cap {
  display: block;
  margin-top: 8px;
  font-size: 13px;
  line-height: 1.6;
  color: var(--txt-dim);
}

/* ---------- 下一步 ---------- */
.page-about .ab-next {
  margin-top: var(--sp-6);
  padding: var(--sp-4);
  display: grid;
  gap: var(--sp-3);
  border: 1px solid var(--gold-line);
  background: linear-gradient(135deg, rgba(201, 162, 75, 0.10) 0%, rgba(31, 111, 92, 0.08) 62%, transparent 100%);
}

.page-about .ab-next__title {
  margin: 0 0 8px;
  font-family: var(--font-display);
  font-weight: 700;
  font-size: clamp(20px, 3.2vw, 26px);
  line-height: 1.4;
  color: var(--paper);
}

.page-about .ab-next__text {
  margin: 0;
  font-size: 14px;
  line-height: 1.8;
  color: var(--txt-dim);
  max-width: 54ch;
}

.page-about .ab-next__actions {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
}

.page-about .ab-next__more {
  margin: var(--sp-3) 0 0;
  font-size: 13px;
}

.page-about .ab-next__more a {
  color: var(--txt-dim);
  text-decoration: none;
  border-bottom: 1px solid var(--line-strong);
  padding-bottom: 2px;
  transition: color var(--dur) var(--ease), border-color var(--dur) var(--ease);
}

.page-about .ab-next__more a:hover {
  color: var(--gold-lt);
  border-color: var(--gold);
}

/* ---------- 断点 ---------- */
@media (min-width: 760px) {
  .page-about .ab-ledger {
    grid-template-columns: repeat(4, minmax(0, 1fr));
  }

  .page-about .ab-ledger__item {
    padding-left: var(--sp-3);
    border-left: 1px solid var(--line-soft);
  }

  .page-about .ab-ledger__item:first-child {
    padding-left: 0;
    border-left: none;
  }

  .page-about .ab-chapter__code {
    font-size: 64px;
  }

  .page-about .ab-tier__sum {
    grid-template-columns: var(--bar-w) 104px minmax(0, 1fr) 22px;
    grid-template-areas: "bar name fit sign";
    align-items: center;
    column-gap: 18px;
    padding: 20px 8px 20px 0;
  }

  .page-about .ab-tier__name {
    font-size: 20px;
  }

  .page-about .ab-eco {
    grid-template-columns: repeat(3, minmax(0, 1fr));
    gap: var(--sp-4);
  }
}

@media (min-width: 900px) {
  .page-about .ab-hero__grid {
    grid-template-columns: minmax(0, 1.25fr) minmax(0, 0.75fr);
    align-items: end;
    gap: var(--sp-5);
  }

  .page-about .ab-team {
    grid-template-columns: minmax(0, 1.05fr) minmax(0, 0.95fr);
    align-items: start;
    gap: var(--sp-4);
  }

  .page-about .ab-team .ab-figure {
    order: 0;
  }

  .page-about .ab-def > div {
    grid-template-columns: 148px minmax(0, 1fr);
    gap: var(--sp-2);
    align-items: baseline;
  }
}

@media (min-width: 1000px) {
  .page-about .ab-body {
    grid-template-columns: 168px minmax(0, 1fr);
    gap: var(--sp-6);
    align-items: start;
  }

  .page-about .ab-index {
    position: sticky;
    top: calc(var(--hdr-h) + 20px);
  }

  .page-about .ab-index__list {
    flex-direction: column;
    flex-wrap: nowrap;
    gap: 0;
  }

  .page-about .ab-index__link {
    padding: 9px 0 9px 14px;
  }
}

@media (min-width: 1200px) {
  .page-about .ab-chapter__grid {
    grid-template-columns: minmax(0, 1fr) 252px;
    gap: var(--sp-4);
    align-items: start;
  }

  .page-about .ab-next {
    grid-template-columns: minmax(0, 1fr) auto;
    align-items: center;
    padding: var(--sp-5);
  }
}

@media (prefers-reduced-motion: reduce) {
  .page-about .ab-index__link,
  .page-about .ab-tier__sum,
  .page-about .ab-tier__sign::before,
  .page-about .ab-tier__sign::after,
  .page-about .ab-next__more a {
    transition: none;
  }
}