.page-about {
  background: var(--pitch-900);
  color: var(--paper-050);
  overflow-x: hidden;
}

.page-about .ps-section {
  padding: clamp(40px, 7vw, 76px) 0;
}

.page-about .ps-section + .ps-section {
  border-top: var(--edge);
}

/* ---------- 首屏 ---------- */
.page-about .ab-hero {
  padding-top: clamp(20px, 3vw, 32px);
}

.page-about .ab-hero__grid {
  display: grid;
  gap: 26px;
  margin-top: 22px;
}

.page-about .ab-hero h1 {
  font-family: var(--font-display);
  font-weight: 900;
  letter-spacing: -0.02em;
  line-height: 1.08;
  font-size: clamp(2rem, 8.4vw, 3.4rem);
  margin: 10px 0 16px;
  max-width: 15em;
}

.page-about .ab-hero .ps-lead {
  font-size: var(--fs-3);
  line-height: 1.8;
  color: var(--paper-050);
  max-width: 36em;
  margin: 0;
}

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

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

.page-about .ab-stats {
  list-style: none;
  margin: 26px 0 0;
  padding: 20px 0 0;
  border-top: var(--edge);
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 16px 14px;
}

.page-about .ab-stats li {
  display: flex;
  flex-direction: column;
  gap: 2px;
}

.page-about .ab-stat__num {
  font-family: var(--font-mono);
  font-variant-numeric: tabular-nums;
  font-weight: 700;
  font-size: clamp(1.6rem, 5vw, 2.1rem);
  line-height: 1.05;
  letter-spacing: 0.02em;
  color: var(--signal-600);
}

.page-about .ab-stat__label {
  font-size: var(--fs-2);
  letter-spacing: 0.04em;
  color: var(--steel-300);
}

/* ---------- 章头 ---------- */
.page-about .ps-chapter {
  margin-bottom: 28px;
}

.page-about .ps-chapter__title {
  letter-spacing: -0.02em;
}

/* ---------- 团队分工 ---------- */
.page-about .ab-graph-wrap {
  border: 2px solid var(--line-500);
  background: var(--pitch-700);
  padding: 14px;
  margin-bottom: 26px;
  box-shadow: var(--shadow-hard);
}

.page-about .ab-graph {
  display: block;
  width: 100%;
  height: auto;
}

.page-about .ab-graph__edges path {
  fill: none;
  stroke: var(--steel-300);
  stroke-width: 2;
}

.page-about .ab-graph__node rect {
  fill: var(--pitch-900);
  stroke: var(--line-500);
  stroke-width: 2;
}

.page-about .ab-graph__node--final rect {
  stroke: var(--signal-600);
}

.page-about .ab-graph__label {
  fill: var(--paper-050);
  font-family: var(--font-display);
  font-size: 21px;
  font-weight: 700;
  letter-spacing: -0.01em;
}

.page-about .ab-graph__sub {
  fill: var(--steel-300);
  font-family: var(--font-mono);
  font-size: 13px;
  letter-spacing: 0.02em;
}

.page-about .ab-roles {
  display: grid;
  gap: 18px;
}

.page-about .ab-role {
  border: 2px solid var(--line-500);
  background: var(--pitch-700);
  padding: 20px 18px 22px;
  box-shadow: var(--shadow-hard);
  transition: transform var(--dur) var(--ease), border-color var(--dur) var(--ease);
}

.page-about .ab-role:hover,
.page-about .ab-role:focus-within {
  border-color: var(--signal-600);
  transform: translateX(2px);
}

.page-about .ab-role:focus-visible {
  outline: 2px solid var(--signal-600);
  outline-offset: 3px;
}

.page-about .ab-role__num {
  font-family: var(--font-mono);
  font-variant-numeric: tabular-nums;
  font-size: 2.6rem;
  font-weight: 700;
  line-height: 1;
  letter-spacing: 0.02em;
  color: var(--signal-600);
  margin: 0 0 8px;
}

.page-about .ab-role__title {
  font-size: var(--fs-4);
  letter-spacing: -0.01em;
  margin: 0 0 10px;
}

.page-about .ab-role__desc {
  margin: 0 0 14px;
  font-size: var(--fs-3);
  line-height: 1.75;
  color: var(--paper-050);
}

.page-about .ab-role__shift {
  margin: 0;
  padding-top: 10px;
  border-top: 1px solid var(--line-500);
  font-family: var(--font-mono);
  font-size: var(--fs-2);
  letter-spacing: 0.02em;
  color: var(--steel-300);
}

/* ---------- 三道关 ---------- */
.page-about .ab-steps {
  list-style: none;
  margin: 0;
  padding: 0;
  display: grid;
  gap: 22px;
}

.page-about .ab-step {
  border-top: 2px solid var(--line-500);
  padding-top: 16px;
}

.page-about .ab-step__no {
  font-family: var(--font-mono);
  font-size: var(--fs-2);
  letter-spacing: 0.08em;
  color: var(--amber-400);
  margin: 0 0 8px;
}

.page-about .ab-step__title {
  font-size: var(--fs-4);
  letter-spacing: -0.01em;
  margin: 0 0 8px;
}

.page-about .ab-step p:last-child {
  margin: 0;
  font-size: var(--fs-3);
  line-height: 1.75;
  color: var(--paper-050);
  max-width: 38em;
}

.page-about .ab-check__figure {
  margin: 28px 0 0;
}

/* ---------- 四个系列 ---------- */
.page-about .ab-series {
  list-style: none;
  margin: 0;
  padding: 0;
  display: grid;
  gap: 18px;
}

.page-about .ab-series__item {
  border: 2px solid var(--line-500);
  background: var(--pitch-700);
  padding: 20px 18px;
  transition: border-color var(--dur) var(--ease), transform var(--dur) var(--ease);
}

.page-about .ab-series__item:hover {
  border-color: var(--signal-600);
  transform: translateX(2px);
}

.page-about .ab-series__tag {
  display: inline-block;
  margin: 0 0 12px;
  padding: 3px 9px;
  background: var(--amber-400);
  color: var(--ink-950);
  font-family: var(--font-mono);
  font-size: var(--fs-1);
  font-weight: 700;
  letter-spacing: 0.08em;
}

.page-about .ab-series__item h3 {
  font-size: var(--fs-4);
  letter-spacing: -0.01em;
  margin: 0 0 8px;
}

.page-about .ab-series__item p:last-child {
  margin: 0;
  font-size: var(--fs-3);
  line-height: 1.75;
  color: var(--paper-050);
}

/* ---------- 版本时间线 ---------- */
.page-about .ab-tl__figure {
  margin: 0 0 24px;
}

.page-about .ab-verbar {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
  margin: 0 0 28px;
}

.page-about .ab-verbar a {
  display: inline-block;
  padding: 6px 12px;
  border: 2px solid var(--line-500);
  color: var(--paper-050);
  font-family: var(--font-mono);
  font-size: var(--fs-2);
  letter-spacing: 0.04em;
  text-decoration: none;
  transition: border-color var(--dur) var(--ease), color var(--dur) var(--ease);
}

.page-about .ab-verbar a:hover,
.page-about .ab-verbar a:focus-visible {
  border-color: var(--signal-600);
  color: var(--signal-600);
}

.page-about .ab-tl {
  list-style: none;
  margin: 0;
  padding: 0;
}

.page-about .ab-tl__item {
  position: relative;
  padding: 0 0 34px 28px;
}

.page-about .ab-tl__item::before {
  content: "";
  position: absolute;
  left: 7px;
  top: 22px;
  bottom: 0;
  width: 2px;
  background: var(--line-500);
}

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

.page-about .ab-tl__item::after {
  content: "";
  position: absolute;
  left: 2px;
  top: 8px;
  width: 12px;
  height: 12px;
  background: var(--muted-400);
  border: 2px solid var(--pitch-900);
  transition: background var(--dur) var(--ease);
}

.page-about .ab-tl__item:target::after {
  background: var(--signal-600);
}

.page-about .ab-tl__meta {
  display: flex;
  align-items: baseline;
  gap: 10px;
  margin-bottom: 10px;
}

.page-about .ab-tl__ver {
  font-family: var(--font-mono);
  font-variant-numeric: tabular-nums;
  font-weight: 700;
  font-size: var(--fs-4);
  letter-spacing: 0.02em;
  color: var(--signal-600);
}

.page-about .ab-tl__stage {
  font-family: var(--font-mono);
  font-size: var(--fs-2);
  letter-spacing: 0.06em;
  color: var(--steel-300);
}

.page-about .ab-tl__card {
  border: 2px solid var(--line-500);
  background: var(--pitch-700);
  padding: 18px 16px 20px;
  box-shadow: var(--shadow-hard);
  transition: border-color var(--dur) var(--ease), box-shadow var(--dur) var(--ease);
}

.page-about .ab-tl__item:target .ab-tl__card {
  border-color: var(--signal-600);
  box-shadow: var(--shadow-signal);
}

.page-about .ab-tl__card h3 {
  font-size: var(--fs-4);
  letter-spacing: -0.01em;
  margin: 0 0 8px;
}

.page-about .ab-tl__card p {
  margin: 0;
  font-size: var(--fs-3);
  line-height: 1.75;
  color: var(--paper-050);
  max-width: 40em;
}

/* ---------- 数据来源 ---------- */
.page-about .ab-source__grid {
  display: grid;
  gap: 26px;
}

.page-about .ab-source__text {
  margin: 0;
  font-size: var(--fs-3);
  line-height: 1.8;
  color: var(--paper-050);
  max-width: 36em;
}

.page-about .ab-source__facts {
  list-style: none;
  margin: 20px 0 0;
  padding: 0;
  display: grid;
  gap: 0;
}

.page-about .ab-source__facts li {
  display: flex;
  align-items: baseline;
  gap: 14px;
  padding: 12px 0;
  border-bottom: 1px solid var(--line-500);
  font-size: var(--fs-3);
  line-height: 1.6;
  color: var(--paper-050);
}

.page-about .ab-source__num {
  font-family: var(--font-mono);
  font-variant-numeric: tabular-nums;
  font-weight: 700;
  font-size: var(--fs-5);
  line-height: 1;
  letter-spacing: 0.02em;
  color: var(--amber-400);
  min-width: 2.4em;
  flex: 0 0 auto;
}

.page-about .ab-source__board {
  padding: 18px 16px 14px;
  overflow-x: auto;
}

.page-about .ab-table {
  width: 100%;
  border-collapse: collapse;
  font-size: var(--fs-2);
  color: var(--ink-950);
}

.page-about .ab-table caption {
  text-align: left;
  font-family: var(--font-mono);
  font-size: var(--fs-2);
  letter-spacing: 0.04em;
  color: var(--ink-950);
  padding: 0 0 12px;
}

.page-about .ab-table th,
.page-about .ab-table td {
  text-align: left;
  vertical-align: top;
  padding: 10px 8px;
  border-bottom: 1px solid rgba(7, 11, 10, 0.25);
}

.page-about .ab-table thead th {
  border-bottom: 2px solid var(--ink-950);
  font-weight: 700;
}

.page-about .ab-table tbody th {
  font-weight: 500;
}

.page-about .ab-table tbody tr:last-child th,
.page-about .ab-table tbody tr:last-child td {
  border-bottom: none;
}

/* ---------- 产能节奏 ---------- */
.page-about .ab-rhythm__grid {
  display: grid;
  gap: 26px;
}

.page-about .ab-rhythm__text {
  margin: 0 0 16px;
  font-size: var(--fs-3);
  line-height: 1.8;
  color: var(--paper-050);
  max-width: 36em;
}

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

.page-about .ab-metrics {
  list-style: none;
  margin: 0;
  padding: 0;
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 1px;
  background: var(--line-500);
  border: 2px solid var(--line-500);
}

.page-about .ab-metrics li {
  background: var(--pitch-700);
  padding: 18px 14px;
}

.page-about .ab-metric__num {
  display: block;
  font-family: var(--font-mono);
  font-variant-numeric: tabular-nums;
  font-weight: 700;
  font-size: clamp(1.5rem, 5.5vw, 2rem);
  line-height: 1.1;
  letter-spacing: 0.02em;
  color: var(--paper-050);
}

.page-about .ab-metric__num--signal {
  color: var(--signal-600);
}

.page-about .ab-metric__unit {
  font-size: 0.55em;
  margin-left: 2px;
  color: var(--steel-300);
}

.page-about .ab-metric__label {
  display: block;
  margin-top: 6px;
  font-family: var(--font-mono);
  font-size: var(--fs-1);
  letter-spacing: 0.06em;
  color: var(--steel-300);
}

/* ---------- CTA ---------- */
.page-about .ab-cta {
  padding-bottom: clamp(52px, 9vw, 96px);
}

.page-about .ab-cta__panel {
  border: 2px solid var(--line-500);
  background: var(--ink-950);
  padding: clamp(24px, 5vw, 40px);
  box-shadow: var(--shadow-hard);
}

.page-about .ab-cta__panel h2 {
  font-size: clamp(1.5rem, 5vw, 2.25rem);
  letter-spacing: -0.02em;
  margin: 0 0 12px;
}

.page-about .ab-cta__panel p {
  margin: 0;
  max-width: 38em;
  font-size: var(--fs-3);
  line-height: 1.75;
  color: var(--steel-300);
}

.page-about .ab-cta__actions {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
  margin-top: 22px;
}

/* ---------- 中屏 ---------- */
@media (min-width: 820px) {
  .page-about .ab-series {
    grid-template-columns: 5fr 7fr;
    gap: 24px 28px;
    padding-bottom: 40px;
  }

  .page-about .ab-series__item:nth-child(even) {
    margin-top: 36px;
  }
}

/* ---------- 桌面 ---------- */
@media (min-width: 900px) {
  .page-about .ab-hero__grid {
    grid-template-columns: 7fr 5fr;
    align-items: end;
    gap: 44px;
  }

  .page-about .ab-stats {
    grid-template-columns: repeat(4, minmax(0, 1fr));
    gap: 14px 20px;
  }

  .page-about .ab-check__grid {
    display: grid;
    grid-template-columns: 7fr 5fr;
    gap: 44px;
    align-items: start;
  }

  .page-about .ab-step:nth-child(2) {
    margin-top: 26px;
  }

  .page-about .ab-step:nth-child(3) {
    margin-top: 52px;
  }

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

  .page-about .ab-source__grid {
    grid-template-columns: 5fr 7fr;
    gap: 44px;
    align-items: start;
  }

  .page-about .ab-rhythm__grid {
    grid-template-columns: 7fr 5fr;
    gap: 44px;
    align-items: start;
  }
}

@media (min-width: 860px) {
  .page-about .ab-roles {
    grid-template-columns: 5fr 4fr 3fr;
    align-items: start;
  }

  .page-about .ab-role:nth-child(2) {
    margin-top: 32px;
  }

  .page-about .ab-role:nth-child(3) {
    margin-top: 64px;
  }

  .page-about .ab-tl__item {
    display: grid;
    grid-template-columns: 118px minmax(0, 1fr);
    column-gap: 28px;
    padding: 0 0 42px 0;
  }

  .page-about .ab-tl__item::before {
    left: 100px;
    top: 24px;
  }

  .page-about .ab-tl__item::after {
    left: 95px;
    top: 26px;
  }

  .page-about .ab-tl__meta {
    flex-direction: column;
    align-items: flex-end;
    text-align: right;
    gap: 4px;
    margin: 0;
    padding: 20px 34px 0 0;
  }
}

@media (min-width: 1040px) {
  .page-about .ab-tl__item:nth-child(even) .ab-tl__card {
    margin-left: 18px;
  }
}

@media (prefers-reduced-motion: reduce) {
  .page-about .ab-role,
  .page-about .ab-series__item,
  .page-about .ab-verbar a,
  .page-about .ab-tl__card,
  .page-about .ab-tl__item::after {
    transition: none;
  }

  .page-about .ab-role:hover,
  .page-about .ab-series__item:hover {
    transform: none;
  }
}