.page-about {
  --ab-sec-y: clamp(54px, 6.8vw, 96px);
  --ab-rule: rgba(26, 26, 26, 0.16);
  background-color: var(--paper);
  color: var(--ink);
  font-family: var(--font-sans);
  font-size: 17px;
  line-height: 1.75;
  overflow-x: clip;
}

.page-about h1,
.page-about h2,
.page-about h3 {
  font-family: var(--font-serif);
  font-weight: 800;
  line-height: 1.2;
  margin: 0;
  text-wrap: balance;
}

.page-about p {
  margin: 0 0 1em;
}

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

.page-about a {
  color: var(--purple);
}

/* ---------- 首屏框景 ---------- */

.page-about .ab-hero {
  padding-top: calc(var(--bar-h) + clamp(18px, 3vw, 40px));
  padding-bottom: clamp(34px, 4.6vw, 64px);
  background:
    repeating-linear-gradient(
      90deg,
      rgba(26, 26, 26, 0.06) 0,
      rgba(26, 26, 26, 0.06) 1px,
      transparent 1px,
      transparent 96px
    ),
    var(--paper);
}

.page-about .ab-hero .breadcrumb {
  margin-bottom: clamp(16px, 2.2vw, 26px);
}

.page-about .ab-frame {
  position: relative;
  border: var(--line) solid var(--ink);
  background: var(--paper);
  box-shadow: var(--shadow-hard);
  padding: clamp(20px, 3.2vw, 46px);
}

.page-about .ab-frame::before,
.page-about .ab-frame::after {
  content: "";
  position: absolute;
  width: 58px;
  height: 58px;
  border: 3px solid var(--gold);
  pointer-events: none;
}

.page-about .ab-frame::before {
  top: -3px;
  left: -3px;
  border-right: 0;
  border-bottom: 0;
}

.page-about .ab-frame::after {
  right: -3px;
  bottom: -3px;
  border-top: 0;
  border-left: 0;
}

.page-about .ab-frame__grid {
  display: grid;
  gap: clamp(22px, 3.2vw, 46px);
  grid-template-columns: minmax(0, 1fr);
  align-items: center;
}

.page-about .ab-frame__copy h1 {
  font-size: clamp(31px, 5.4vw, 60px);
  font-weight: 900;
  letter-spacing: -0.012em;
  margin: 0.3em 0 0.55em;
}

.page-about .ab-frame__copy .lede {
  font-size: clamp(16px, 1.4vw, 18px);
  line-height: 1.8;
  color: var(--ink);
  max-width: 34em;
  margin-bottom: 0;
}

.page-about .ab-frame__actions {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
  margin-top: clamp(20px, 2.6vw, 30px);
}

.page-about .ab-frame__media {
  margin: 0;
  border: var(--line) solid var(--ink);
  background: var(--wheat);
}

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

.page-about .ab-frame__media figcaption {
  border-top: var(--line) solid var(--ink);
  background: var(--wheat);
  padding: 10px 14px;
  font-size: 13px;
  color: var(--muted);
  line-height: 1.6;
}

/* ---------- 概览数据横带 ---------- */

.page-about .ab-strip {
  background: var(--green-ink);
  border-top: var(--line) solid var(--ink);
  border-bottom: var(--line) solid var(--ink);
  padding: clamp(24px, 3.4vw, 42px) 0;
}

.page-about .ab-strip__list {
  list-style: none;
  margin: 0;
  padding: 0;
  display: grid;
  gap: clamp(18px, 2.4vw, 30px);
  grid-template-columns: repeat(2, minmax(0, 1fr));
}

.page-about .ab-strip__item {
  border-top: 2px solid rgba(212, 160, 23, 0.55);
  padding-top: 12px;
}

.page-about .ab-strip__num {
  display: block;
  font-family: var(--font-mono);
  font-variant-numeric: tabular-nums;
  font-size: clamp(30px, 4vw, 50px);
  font-weight: 600;
  line-height: 1;
  color: var(--gold);
}

.page-about .ab-strip__label {
  display: block;
  margin-top: 10px;
  font-size: 13px;
  letter-spacing: 0.08em;
  line-height: 1.5;
  color: rgba(245, 241, 232, 0.82);
}

/* ---------- 通用章节 ---------- */

.page-about .ab-sec {
  padding: var(--ab-sec-y) 0;
  border-top: var(--line) solid var(--ab-rule);
}

.page-about .ab-sec--last {
  padding-bottom: clamp(64px, 8vw, 110px);
}

.page-about .ab-sechead {
  display: flex;
  align-items: flex-start;
  gap: clamp(14px, 2vw, 28px);
  margin-bottom: clamp(18px, 2.4vw, 28px);
}

.page-about .ab-sechead__num {
  flex: 0 0 auto;
  font-family: var(--font-mono);
  font-variant-numeric: tabular-nums;
  font-size: clamp(32px, 4.6vw, 58px);
  font-weight: 600;
  line-height: 0.88;
  letter-spacing: -0.03em;
  color: var(--purple);
  padding-bottom: 8px;
  border-bottom: 6px solid var(--gold);
}

.page-about .ab-sechead__text .label {
  margin-bottom: 6px;
}

.page-about .ab-sechead__text h2 {
  font-size: clamp(25px, 3.5vw, 42px);
}

.page-about .ab-sec__lede {
  max-width: 44em;
  font-size: 17px;
  color: var(--ink);
  margin-bottom: clamp(24px, 3vw, 38px);
}

.page-about .ab-link {
  font-size: 14px;
  font-weight: 700;
  letter-spacing: 0.04em;
  color: var(--purple);
  text-decoration: none;
  border-bottom: 2px solid var(--gold);
  padding-bottom: 2px;
}

.page-about .ab-link:hover,
.page-about .ab-link:focus-visible {
  color: var(--purple-deep);
  border-bottom-color: var(--purple-deep);
}

/* ---------- 时间线 ---------- */

.page-about .ab-timeline {
  list-style: none;
  margin: 0;
  padding: 0;
  display: grid;
  gap: clamp(18px, 2.4vw, 28px);
}

.page-about .ab-timeline__item {
  position: relative;
  display: grid;
  grid-template-columns: 30px minmax(0, 1fr);
  gap: clamp(14px, 2vw, 26px);
}

.page-about .ab-timeline__item::before {
  content: "";
  position: absolute;
  left: 14px;
  top: 30px;
  bottom: calc(-1 * clamp(18px, 2.4vw, 28px) - 4px);
  width: 2px;
  background: rgba(26, 26, 26, 0.2);
}

.page-about .ab-timeline__item:last-child::before {
  display: none;
}

.page-about .ab-timeline__marker {
  position: relative;
  z-index: 1;
  display: grid;
  place-items: center;
  width: 30px;
  height: 30px;
  background: var(--paper);
}

.page-about .ab-timeline__marker svg {
  display: block;
}

.page-about .ab-stage {
  padding: clamp(16px, 2vw, 24px) clamp(18px, 2.2vw, 26px);
}

.page-about .ab-stage__title {
  font-size: clamp(19px, 2vw, 23px);
  margin-bottom: 8px;
}

.page-about .ab-stage p {
  font-size: 16px;
  color: var(--ink);
}

/* ---------- 7 + 5 分栏 ---------- */

.page-about .ab-7-5 {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: clamp(20px, 2.6vw, 32px);
  margin-bottom: clamp(26px, 3.2vw, 42px);
}

.page-about .ab-7-5__main p {
  font-size: 17px;
}

.page-about .ab-7-5__aside {
  align-self: start;
  display: grid;
  gap: 2px;
}

.page-about .ab-note__kicker {
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.14em;
  text-transform: uppercase;
  color: var(--purple);
  margin: 10px 0 0;
}

.page-about .ab-note__body {
  font-size: 16px;
  margin: 0 0 6px;
}

/* ---------- 对照表 ---------- */

.page-about .ab-table-wrap {
  border: var(--line) solid var(--ink);
  background: var(--paper);
  box-shadow: var(--shadow-hard);
  overflow: hidden;
}

.page-about .ab-table {
  width: 100%;
  border-collapse: collapse;
}

.page-about .ab-table__caption {
  caption-side: top;
  text-align: left;
  padding: 14px 18px;
  background: var(--ink);
  color: var(--paper);
  font-size: 13px;
  letter-spacing: 0.08em;
}

.page-about .ab-table th {
  background: var(--green);
  color: var(--paper);
  font-size: 13px;
  letter-spacing: 0.1em;
  text-align: left;
  padding: 13px 18px;
  border-bottom: var(--line) solid var(--ink);
}

.page-about .ab-table td {
  padding: 13px 18px;
  font-size: 15px;
  border-bottom: 1px solid rgba(26, 26, 26, 0.18);
  vertical-align: top;
}

.page-about .ab-table tbody tr:nth-child(even) {
  background: var(--wheat);
}

.page-about .ab-table tbody tr:last-child td {
  border-bottom: 0;
}

.page-about .ab-table td:first-child {
  font-weight: 700;
  color: var(--purple-deep);
}

/* ---------- 图文混排 ---------- */

.page-about .ab-media-text {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: clamp(22px, 3vw, 44px);
  align-items: start;
}

.page-about .ab-media-text__figure {
  margin: 0;
  border: var(--line) solid var(--ink);
  background: var(--wheat);
  box-shadow: var(--shadow-hard);
}

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

.page-about .ab-media-text__figure figcaption {
  border-top: var(--line) solid var(--ink);
  padding: 10px 14px;
  font-size: 13px;
  line-height: 1.6;
  color: var(--muted);
}

.page-about .ab-media-text__body > p {
  max-width: 40em;
}

/* ---------- 四步流程 ---------- */

.page-about .ab-steps {
  list-style: none;
  margin: clamp(24px, 3vw, 36px) 0 0;
  padding: 0;
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: clamp(18px, 2.4vw, 26px);
}

.page-about .ab-steps__item {
  position: relative;
  border-top: var(--line) solid var(--ink);
  padding-top: 20px;
}

.page-about .ab-steps__item::before {
  content: "";
  position: absolute;
  top: -8px;
  left: 0;
  width: 12px;
  height: 12px;
  background: var(--gold);
  border: 2px solid var(--ink);
  transform: rotate(45deg);
}

.page-about .ab-steps__num {
  display: block;
  font-family: var(--font-mono);
  font-variant-numeric: tabular-nums;
  font-size: 26px;
  font-weight: 600;
  color: var(--green);
  line-height: 1;
}

.page-about .ab-steps__title {
  font-size: 19px;
  margin: 8px 0 6px;
}

.page-about .ab-steps__item p {
  font-size: 15px;
  color: var(--muted);
  margin: 0;
}

/* ---------- 分段控件 ---------- */

.page-about .ab-tabs {
  margin-top: clamp(8px, 1.6vw, 18px);
}

.page-about .ab-tabs__list {
  display: flex;
  flex-wrap: wrap;
  gap: 0;
  border-bottom: var(--line) solid var(--ink);
}

.page-about .ab-tabs__tab {
  appearance: none;
  -webkit-appearance: none;
  background: transparent;
  border: var(--line) solid transparent;
  border-bottom: 0;
  margin-bottom: -2px;
  min-height: 44px;
  padding: 11px 16px;
  font-family: var(--font-sans);
  font-size: 14px;
  letter-spacing: 0.06em;
  color: var(--muted);
  cursor: pointer;
  transition: background-color 200ms var(--ease), color 200ms var(--ease);
}

.page-about .ab-tabs__tab:hover,
.page-about .ab-tabs__tab:focus-visible {
  color: var(--ink);
  background: var(--wheat);
}

.page-about .ab-tabs__tab[aria-selected="true"] {
  color: var(--ink);
  font-weight: 700;
  background: var(--wheat);
  border-color: var(--ink);
  border-bottom: var(--line) solid var(--wheat);
}

.page-about .ab-tabs__panels {
  border: var(--line) solid var(--ink);
  border-top: 0;
  background: var(--paper);
}

.page-about .ab-role {
  padding: clamp(20px, 2.6vw, 32px);
  display: none;
}

.page-about .ab-role[hidden] {
  display: none;
}

.page-about .ab-tabs__panel[data-panel].is-active,
.page-about .ab-tabs__panel[data-panel]:not([hidden]):first-child {
  display: block;
}

.page-about .ab-role__count {
  font-family: var(--font-mono);
  font-variant-numeric: tabular-nums;
  font-size: 14px;
  letter-spacing: 0.12em;
  color: var(--muted);
  margin: 0 0 6px;
}

.page-about .ab-role__num {
  font-size: clamp(38px, 5vw, 58px);
  font-weight: 600;
  line-height: 1;
  color: var(--purple);
  margin-right: 4px;
  border-bottom: 5px solid var(--gold);
  padding-bottom: 4px;
}

.page-about .ab-role__title {
  font-size: clamp(20px, 2.3vw, 26px);
  margin: 14px 0 10px;
}

.page-about .ab-role p:last-child {
  max-width: 46em;
  font-size: 16px;
}

/* ---------- 版本刻度 ---------- */

.page-about .ab-gens {
  position: relative;
  margin-top: clamp(22px, 3vw, 34px);
}

.page-about .ab-gens__list {
  list-style: none;
  margin: 0;
  padding: 0;
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: clamp(16px, 2.2vw, 26px);
}

.page-about .ab-gens__item {
  position: relative;
  padding-top: 26px;
  border-top: 2px solid rgba(26, 26, 26, 0.28);
}

.page-about .ab-gens__item::before {
  content: "";
  position: absolute;
  top: -8px;
  left: 0;
  width: 14px;
  height: 14px;
  background: var(--paper);
  border: 2px solid var(--ink);
}

.page-about .ab-gens__item--now::before {
  background: var(--gold);
  border-width: 3px;
}

.page-about .ab-gens__gen {
  display: block;
  font-family: var(--font-mono);
  font-size: 14px;
  font-weight: 600;
  letter-spacing: 0.08em;
  color: var(--green);
  margin-bottom: 6px;
}

.page-about .ab-gens__item--now .ab-gens__gen {
  color: var(--purple);
}

.page-about .ab-gens__note {
  display: block;
  font-size: 14px;
  line-height: 1.65;
  color: var(--muted);
}

.page-about .ab-subnote {
  margin-top: clamp(26px, 3.4vw, 44px);
  padding: clamp(20px, 2.6vw, 32px);
  background: var(--wheat);
  border-left: 6px solid var(--gold);
  border-top: var(--line) solid var(--ink);
  border-right: var(--line) solid var(--ink);
  border-bottom: var(--line) solid var(--ink);
}

.page-about .ab-subnote__title {
  font-size: 20px;
  margin-bottom: 10px;
}

.page-about .ab-subnote p {
  font-size: 16px;
  max-width: 52em;
}

.page-about .ab-subnote__links {
  display: flex;
  flex-wrap: wrap;
  gap: 20px;
  margin-top: 16px;
  margin-bottom: 0;
}

/* ---------- 紫色横带 ---------- */

.page-about .ab-band {
  background: var(--purple);
  border-top: var(--line) solid var(--ink);
  border-bottom: var(--line) solid var(--ink);
  padding: clamp(30px, 4.4vw, 56px) 0;
}

.page-about .ab-band__text {
  font-family: var(--font-serif);
  font-weight: 700;
  font-size: clamp(20px, 2.6vw, 32px);
  line-height: 1.4;
  color: var(--paper);
  max-width: 30em;
  margin: 0;
}

/* ---------- 更新节奏 ---------- */

.page-about .ab-rhythm {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: clamp(18px, 2.4vw, 26px);
}

.page-about .ab-rhythm__item {
  padding: clamp(20px, 2.4vw, 28px);
  border-left: 6px solid var(--green);
}

.page-about .ab-rhythm__kicker {
  font-family: var(--font-mono);
  font-size: 13px;
  letter-spacing: 0.1em;
  color: var(--gold);
  background: var(--ink);
  display: inline-block;
  padding: 4px 10px;
  margin: 0 0 14px;
}

.page-about .ab-rhythm__title {
  font-size: clamp(19px, 2vw, 23px);
  margin-bottom: 8px;
}

.page-about .ab-rhythm__item p:last-child {
  font-size: 15px;
  color: var(--muted);
}

/* ---------- 结尾通道 ---------- */

.page-about .ab-cta {
  margin-top: clamp(30px, 4vw, 52px);
  border: var(--line) solid var(--ink);
  background: var(--green-ink);
  box-shadow: var(--shadow-hard);
  padding: clamp(22px, 3vw, 36px);
  display: grid;
  gap: 18px;
}

.page-about .ab-cta__text {
  color: var(--paper);
  font-size: 17px;
  max-width: 40em;
  margin: 0;
}

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

/* ---------- 响应式 ---------- */

@media (min-width: 640px) {
  .page-about .ab-strip__list {
    grid-template-columns: repeat(3, minmax(0, 1fr));
  }

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

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

@media (min-width: 860px) {
  .page-about .ab-frame__grid {
    grid-template-columns: 1.04fr 0.96fr;
  }

  .page-about .ab-7-5 {
    grid-template-columns: 7fr 5fr;
  }

  .page-about .ab-media-text {
    grid-template-columns: 5fr 7fr;
  }

  .page-about .ab-media-text--flip {
    grid-template-columns: 7fr 5fr;
  }

  .page-about .ab-media-text--flip .ab-media-text__figure {
    order: 2;
  }

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

@media (min-width: 1024px) {
  .page-about .ab-strip__list {
    grid-template-columns: repeat(5, minmax(0, 1fr));
  }

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

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

  .page-about .ab-gens__list {
    grid-template-columns: repeat(7, minmax(0, 1fr));
  }
}

@media (max-width: 720px) {
  .page-about .ab-table-wrap {
    border: 0;
    box-shadow: none;
    background: transparent;
  }

  .page-about .ab-table,
  .page-about .ab-table thead,
  .page-about .ab-table tbody,
  .page-about .ab-table tr,
  .page-about .ab-table th,
  .page-about .ab-table td {
    display: block;
    width: 100%;
  }

  .page-about .ab-table__caption {
    background: var(--ink);
    padding: 12px 14px;
  }

  .page-about .ab-table thead {
    display: none;
  }

  .page-about .ab-table tbody tr {
    border: var(--line) solid var(--ink);
    border-bottom: 0;
    background: var(--paper);
    padding: 12px 14px;
  }

  .page-about .ab-table tbody tr:nth-child(even) {
    background: var(--wheat);
  }

  .page-about .ab-table tbody tr:last-child {
    border-bottom: var(--line) solid var(--ink);
  }

  .page-about .ab-table td {
    border: 0;
    padding: 5px 0;
  }

  .page-about .ab-table td::before {
    content: attr(data-label);
    display: block;
    font-size: 12px;
    letter-spacing: 0.12em;
    color: var(--muted);
    margin-bottom: 2px;
  }
}

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